Jihed Hsouna

Houda Ilahi

Jia-Cheng Han

Takwa Gritli

Walid Ellouze

Xiao Xia Zhang

Maroua Mansouri

Praveen Rahi

Mustapha Missbah

El Idrissi

Missbah Mustapha

El Idrissi

Mouad Lamrabet

M'hamed Oubla

Pierre Emmanuel Courty

Daniel Wipf

James T Tambong
email: james.tambong@agr.gc.ca

Bacem Mnasri
email: bacemmnasri@yahoo.com

Rhizobium acaciae sp. nov., a new nitrogen-fixing symbiovar isolated from root nodules of Acacia saligna in Tunisia

Keywords: Acacia saligna, nodules, Rhizobium acaciae, Rhizobium leguminosarum complex ANI, Average Nucleotide Identity, dDDH, Digital DNA-DNA hybridization, YMA, Yeast Mannitol Agar

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Acacia is a multipurpose, fast-growing tree species of the family Fabaceae. This genus comprises over 1350 species that are distributed in the warm regions of the world, including Australia, the Americas, Africa and Asia [START_REF] Adiamo | Acacia seed proteins: low or high quality? a comprehensive review[END_REF]. Acacia saligna (Labill.) Wendl is an invasive, fast-growing woody tree that has been introduced to the Mediterranean coast in the Maghreb area including Tunisia for many different purposes, including revegetation of arid regions [START_REF] Swelim | Survival and shelf life of leguminous trees rhizobia as affected by sterilization, culture dilution and maltose and trace elements enriched carrier[END_REF]. These plants enrich soil nitrogen in symbiotic association with various genera of rhizobia such as Mesorhizobium, Rhizobium, Ensifer and preferentially Bradyrhizobium [START_REF] Amrani | Phenotypic and genotypic characterization of rhizobia associated with Acacia saligna (Labill.) Wendl. in nurseries from Algeria[END_REF]. In a recent study, Hsouna et al. [4] reported that Acacia saligna plants grown in Tunisian soils are promiscuous and were nodulated by fast growing organisms that could constitute putative new species within the genus Rhizobium. The 100 bacterial strains obtained in the study of Hsouna et al. [4] were characterized into three distinct ribotypes based on rrs PCR-RFLP analysis. Sequence analyses of rrs and four housekeeping genes (recA, atpD, gyrB and glnII) assigned 30 isolates to four putative new lineages of the genera Rhizobium and Bradyrhizobium and a single isolate to Sinorhizobium meliloti. One of these new lineages consisted of 10 isolates, including the representative strains 1AS11 T , 1AS12 and 1AS13. Phylogenetic analysis of 1734-bp concatenated sequences of recA, atpD, glnII and gyrB clustered strains 1AS11 T , 1AS12 and 1AS13 in a distinct clade within the R. leguminosarum complex (Rlc). The closest described species were R. laguerreae and R. indicum [4]. Interestingly, based on the divergence of nodA/nodC sequences and host range nodulation patterns used in previous study for symbiovar delineation [START_REF] Rincón-Rosales | Rhizobia with different symbiotic efficiencies nodulate Acaciella angustissima in Mexico, including Sinorhizobium chiapanecum sp. nov. which has common symbiotic genes with Sinorhizobium mexicanum[END_REF][START_REF] Tampakaki | A novel symbiovar (aegeanense) of the genus Ensifer nodulates Vigna unguiculata[END_REF][START_REF] Rogel | Symbiovars in rhizobia reflect bacterial adaptation to legumes[END_REF], strains 1AS11 T , 1AS12 and 1AS13 were classified as a new symbiovar named salignae [4] . The three strains effectively nodulated A. saligna, A. salicina and Leucaena leucocephala, while they failed to nodulate Glycine max, Phaseolus vulgaris and Retama raetam.

In the present study, the taxonomic status of strains 1AS11 T , 1AS12 and 1AS13 was investigated using a polyphasic approach including genome-based analyses.

ISOLATION AND ECOLOGY

The three strains were isolated from root nodules of A. saligna grown in the locality of Borj Cedria in Tunisia [4]. Nodules were surface sterilized and bacteria were extracted following the standard procedures of Vincent [START_REF] Vincent | A Manual for the Practical Study of the Root-nodule Bacteria[END_REF]. Pure single colonies of the bacterial cultures were obtained by repetitive streaking on yeast-mannitol agar (YMA) as described previously [4]. Aliquots of the purified single colonies were preserved in 15 % (v/v) glycerol suspensions at -80 °C. The nodulation and nitrogen-fixation performance of the three novel strains was tested on various legume species.

rrs, recA, atpD, gyrB AND glnII PHYLOGENY

Bacterial DNA was extracted from three isolates and used as template for 50 µl PCR reactions [4]. The rrs gene were sequenced using the primers fD1 and rD1 [START_REF] Weisburg | 16S ribosomal DNA amplification for phylogenetic study[END_REF]. Amplification and sequencing of recA, atpD, glnII and gyrB genes were carried out according to the methods of Hsouna et al. [4]. PCR-amplified products were purified from agarose gels using the EZ-10 spin column DNA gel extraction Minipreps Kit (Bio Basic Canada Inc.) following the manufacturer's instructions. Purified DNA fragments were sequenced at the Centre of Biotechnology, Borj-Cédria, Tunisia. The sequence similarities in the DNA databases were examined using the blast program (http://blast.ncbi.nlm.nih.gov/Blast.cgi). The rrs gene sequences were compared with NCBI reference sequences. Sequences were aligned using the ClustalW2 software (www.ebi.ac.uk/Tools/clustalw2/). Maximum-likelihood (ML) phylogenetic trees were inferred using the mega7 [START_REF] Kumar | MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets[END_REF] using the Kimura two-parameter substitution model [START_REF] Kimura | A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences[END_REF] with the pairwise deletion option [START_REF] Gevers | Opinion: re-evaluating prokaryotic species[END_REF]. Bootstrap analysis was based on 1000 re-samplings and values >50 % are shown on the phylogenetic trees.

In the phylogenetic tree based on partial rrs gene sequences (1215 nt), all three new strains grouped together and showed 100 % similarity to R. laguerreae, R. changzhiense, R. anhuiense, R. leguminosarum, R. ruizarguesonis, R. acidisoli, R. hidalgonense, R. indicum, R. sophorae and R. redzepovicii type strains. Except for R. anhuiense, R. acidisoli and R. hidalgonense, these species were recently named to belong to the Rlc [START_REF] Young | Defining the Rhizobium leguminosarum species complex[END_REF]. Fig. S1 (available in the online version of this article) shows an ML phylogenetic tree with the three strains of the proposed R. acaciae sp. nov. clustering with the type strains of the Rlc at a bootstrap value of 76 %. This suggests that the three strains of R. acaciae sp. nov. belong to the Rlc. Neighbour-joining and minimum-evolution algorithms were also used to reconstruct phylogenetic relationships and showed similar topologies (Figs S2 andS3). Given that, rrs phylogenies have been reported to show low-resolution power among closely related species [START_REF] Mulet | DNA sequence-based analysis of the Pseudomonas species[END_REF][START_REF] González | Pseudomonas asturiensis sp. nov., isolated from soybean and weeds[END_REF], multilocus sequence analysis was performed using four housekeeping genes (recA, atpD, gyrB and glnII). Based on recA-atpD-gyrB-glnII concatenated sequences (1734 bp), the three novel strains were divergent from strains of type strains of previously described Rhizobium species of the Rlc group and the closest described species with were R. indicum, R. laguerrea and R. changzhiense. Based on the phylogenetic analysis of recA-atpD-gyrB-glnII, the three strains of R. acaciae sp. nov. clustered in a distinct clade (bootstrap of 100 %), an indication that these strains are unique (Fig. 1).

GENOMIC RELATEDNESS AND PHYLOGENOMICS

Draft whole-genome sequences of the three new strains were generated using Illumina NovaSeq 6000 technology (Génome Québec, Montreal, Canada). The quality of the raw reads (2×150 bp) was checked using the FastQC algorithm [START_REF] Andrews | A quality control tool for high throughput sequence data[END_REF]. De novo assembly was

+ + - + + N-Acetyl-β-d-mannosamine + + + - + - N-Acetyl-d-galactosamine - - - - + - N-Acetyl neuraminic acid - - - - - + α-d-Glucose + + + - - - d-Mannose + + + - - - d-Galactose + + + - + + d-Fucose + + + - + + l-Rhamnose + + + - - + dArabitol + + + - - + myo-Inositol + + + - - + Glycerol + + + - + + d-Fructose-6-PO 4 - - - + + - l-Glutamic acid + + + - + + l-Histidine + + + - - + l-Pyroglutamic acid + + + - + - d-Galacturonic acid - - - + + - d-Gluconic acid + + + - + + d-Glucuronic acid - - - + + - Mucic acid - - - - - + Quinic acid - - - - - + Methyl pyruvate + + + - - - l-Lactic acid - - - - - + d-Malic acid - - - - - + l-Malic acid - - - - + w Tween 40 - - - - w + α-Hydroxy-butyric acid - - - - - + β-Hydroxy-d,l butyric acid - - - - + +
Continued performed using Unicyler version 0.4.8 [START_REF] Wick | Unicycler: resolving bacterial genome assemblies from short and long sequencing reads[END_REF] and assessed using quast [START_REF] Gurevich | QUAST: quality assessment tool for genome assemblies[END_REF] as implemented in patric 3.6.12 [START_REF] Wattam | PATRIC, the bacterial bioinformatics database and analysis resource[END_REF][START_REF] Davis | The PATRIC bioinformatics resource center: expanding data and analysis capabilities[END_REF]. Contigs of length <300 bp were discarded. Where required, assembled genome sequences were annotated using Prokka version 1.12 [START_REF] Seemann | Prokka: rapid prokaryotic genome annotation[END_REF]. Table 1 shows the basic statistics of the sequenced draft genomes. For each of the strains, 33 112 583 raw reads were generated. After quality checks, the readsused in the assembling processed gave an average coverage depth of 1213.9×, 1314.8× and 1226.6× with contig counts of 84, 79 and 112, for strains 1AS11 T , 1AS12 and 1AS13, respectively. The completeness of the genomes was 100 % with coarse and fine consistencies of 99.8-99.9% and 96.8-96.9 %, respectively, with a contamination rate of 0.5 % (CheckM algorithm) [START_REF] Parks | CheckM: assessing the quality of microbial genomes recovered from isolates, single cells, and metagenomes[END_REF]. The largest contigs were 761366, 1 110 614 and 761 366 bases and had N 50 values of 247715, 270 518 and 247 715 bases for strains 1AS11 T , 1AS12 and 1AS13. The total lengths of the draft genomes were 8.01, 7.49 and 8.02 Mb, respectively, with G+C contents of 60.82-60.92 mol% (Table 1). Annotation reports of the genome sequences identified a total of 7714, 7127 and 7758 protein-coding sequences as well as 48 or 50 tRNAs, three rRNAs and one tmRNA (Table 1). The generated new draft whole-genome sequences were used to confirm the uniqueness of these strains relative to closest related Rhizobium species.

Genome-sequence-based digital DNA-DNA hybridization (dDDH; GGDC 3.1 [START_REF] Meier-Kolthoff | Genome sequence-based species delimitation with confidence intervals and improved distance functions[END_REF]), blast-based average nucleotide identity (ANIb; JSpecies [START_REF] Richter | JSpe-ciesWS: a web server for prokaryotic species circumscription based on pairwise genome comparison[END_REF]) and ANI (Fastani [START_REF] Jain | High throughput ANI analysis of 90K prokaryotic genomes reveals clear species boundaries[END_REF]) values were computed and compared to 12 validly published close Rhizobium species to validate the taxonomic position of strains. The three strains (1AS11 T , 1AS12 and 1AS13) exhibited dDDH, ANIb and ANI values significantly above the species-level cut-offs of 70 and 96 %, validating that these three belong to the same Rhizobium species (Table 2). For example, strain 1AS11 T showed dDDH, ANI and ANIb values of 100, 99.99 and 99.97 % with strain 1AS13 (Table 2). Strain 1AS12 exhibited lower dDDH, ANb and ANI values with 1AS11 T but still significantly above the species-level cut-off (Table 2). The type strain of the proposed R. acaciae sp. nov, strain 1AS11 T , had lower relatedness with the 12 closest species with values significantly below the cut-off values of 70 and 96 % for dDDH and ANIb and ANI, respectively ( cut-off species delineation threshold. These data are consistent with the results of the recA-atpD-gyrB-glnII phylogenetic analysis, suggesting that strains 1AS11 T , 1AS12 and 1AS13 constituted a novel species in the genus Rhizobium. The dDDH, ANIb and ANI results were corroborated by the phylogenomics tree [START_REF] Farris | Estimating phylogenetic trees from distance matrices[END_REF][START_REF] Lefort | FastME 2.0: a comprehensive, accurate, and fast distance-based phylogeny inference program[END_REF] inferred using GBDP-derived intergenomic distances and computed on the Type (Strain) Genome Server (TyGS [START_REF] Meier-Kolthoff | TYGS and LPSN: a database tandem for fast and reliable genome-based classification and nomenclature of prokaryotes[END_REF][START_REF] Meier-Kolthoff | TYGS is an automated high-throughput platform for state-of-the-art genome-based taxonomy[END_REF]) (Fig. S4). Also, the uniqueness of strains 1AS11 T , 1AS12 and 1AS13 was validated by phylogenetic analysis of a concatenated alignment of 92 core genes as implemented in the up-to-date bacterial core gene (UBCG) tool [START_REF] Na | UBCG: Up-to-date bacterial core gene set and pipeline for phylogenomic tree reconstruction[END_REF] (Fig. 2). Both TyGS and UBCG pipelines generated phylogenomic trees that showed strains 1AS11 T , 1AS12 and 1AS13 clustering uniquely from the closest known species within the genus Rhizobium (Fig. S4; Fig. 2). Based on these genome data and analyses, these new strains of the genus Rhizobium constitute a new species.

In addition, the whole genome sequences generated in this study were used to locate the proposed new species within the 18 genomospecies (gsp) groupings according to Young et al. [START_REF] Young | Defining the Rhizobium leguminosarum species complex[END_REF] . The UBCG tool was used to implement an ML phylogenomics tree of strains 1AS11 T , 1AS12 and 1AS13 and the proposed representatives of the genomospecies of Young et al. [START_REF] Young | Defining the Rhizobium leguminosarum species complex[END_REF]. Fig. 3 shows an unrooted tree of the R. acaciae strains clustering closely with the representative strain of gsp J. The gsp J was represented by two strains WSM1455 (AJUF01) and WSM1481 (AQUM01) and these strains were classified as unique [START_REF] Young | Defining the Rhizobium leguminosarum species complex[END_REF] but deposited in GenBank as Rhizobium leguminosarum bv. viciae. Interestingly, a taxonomy check using GenBank's algorithm flagged these two strains as "inconclusive " to be classified as R. leguminosarum. These two unique strains, WSM1455 (AJUF01) and WSM1481 (AQUM01), exhibited dDDH and ANI values of 83.10 and 98.07 % with the type strain of the proposed R. acaciae 1AS11 T . These values are significantly above the species-level cut-off of 70 and 96 %, respectively, suggesting that strains WSM1455 and WSM1481 are genetically valid members of the proposed new species, R. acaciae sp. nov. Both WSM1481 and WSM1455 were isolated from roots of Vicia faba plants in the Greek island of Mykonos (GOLD database; https://gold.jgi.doe.gov/organism?id=Go0007354). This suggests that members of the proposed new species, R. acaciae sp. nov., might have preference for plant species of the family Fabaceae, from cultivated legumes (broad beans) to small wild trees, e.g. golden wreath wattle (Acacia saligna).

PHYSIOLOGY AND CHEMOTAXONOMY

Colonies of strains 1AS11 T , 1AS12 and 1AS13, as examined on YMA, were typical rhizobial-like translucent, cream-white and convex. The morphology of the bacterial species was examined with an atomic force microscope (FlexAFM Nanosurf AG) operated in the tapping imaging mode in phase contrast, at room temperature, using a CoreAFM Microscope, Nanosurf Isostage 300. Cells were 0.4-0.5×1-2 µm in size (Fig. S5). The phenotypic and physiological features of the novel isolates were determined and compared with their most related type strains. The characteristics tested included the use of sole carbon and nitrogen sources, tolerance to NaCl, pH, resistance to antibiotics and fatty methyl ester content. Biochemical characteristics, enzyme activities and utilization of carbon sources were performed using the API ZYM systems (07584D and 25 200, bioMérieux) and the Biolog GEN III system following the manufacturers' instructions. Antibiotic resistance testing was carried out on Yeast extract Mannitol (YEM) plates supplemented with five concentrations of each antibiotic (5, 10, 50 80 and 100 µg ml -1 ). The antibiotics used were streptomycin, kanamycin, ampicillin, neomycin, erythromycin, chloramphenicol and tetracycline. Tolerance to NaCl, pH and temperature was checked in liquid YEM as previously reported [START_REF] Mnasri | Salt-tolerant rhizobia isolated from a Tunisian oasis that are highly effective for symbiotic N 2 -fixation with Phaseolus vulgaris constitute a novel biovar (bv. mediterranense) of Sinorhizobium meliloti[END_REF] .The optimum pH for growth was assessed on YMA medium plates adjusted to pH 4-10 using 1 M HCl (pH 4.0 and 5.0) or 1M NaOH (pH 7-10 prior to autoclaving).

Carbon substrate characteristics (Table 3) shared by all three strains of R. acaciae sp. nov. that differed from at least one of their closest related type strains were the ability to utilize trehalose, turanose, raffinose, lactose, melibiose, methyl β-d-glucoside, N-acetyl-d-glucosamine, N-acetyl-β-d-mannosamine, α-d-glucose, d-mannose, d-galactose, d-fucose, l-rhamnose, arabitol and myo-inositol. In addition, strains of R. acaciae were able to use l-glutamic acid, l-histidine and l-pyroglutamic acid. Other characteristics shown by the strains of the novel species that differed from at least one of these closest type strains were their weak positive enzymatic reaction for cystinol-arylamidase, α-mannosidase and β-fucosidase and negative reactions for N-acetylβ-glucosaminase. Rhizobium acaciae sp. nov. strains were resistant to kanamycin (10 µg ml -1 ) and streptomycin (10 µg ml -1 ) but sensitive to lincomycin and rifamycin. Fatty acid methyl esters were analysed using the Microbial Identification System (midi) and the Microbial Identification software package (Sherlock version 6.1; midi database, TSBA6). The fatty acid composition and abundance varied between 1AS11 T and closely related type strains of Rhizobium species (Table 4). Indeed, the amount of C 18 : 1 ω7c 11-methyl in strain 1AS11 T was higher than that in strains FB206 T of R. laguerreae and JKLM12A2 T of R. indicum. Also, we detected small amounts of C 15 : 0 3OH (0.27 %), C 17 : 0 (0.78 %), C 17 : 1 anteiso ω9c (0.32 %), C 17 : 1 ω8c (0.26 %), C 17 : 1 ω6c (0,1 %), C 17 : 0 3OH (0.16 %), C 20 : 1 ω7c (0.45 %) and C 20 : 2 ω6,9c (0.17 %) that were absent in FB206 T and JKLM12A2 T .

DESCRIPTION OF RHIZOBIUM ACACIAE SP. NOV.

Rhizobium acaciae ( a. ca' ci. ae. L. gen. n. acaciae, of the plant genus Acacia the host plant from which the novel species was isolated).

Cells of R. acaciae are Gram-stain-negative, non-spore forming rods. Colony morphology, as examined on YMA, was typical rhizobial-like translucent, cream-white and convex after 2-3 days of incubation at 28 °C. All strains grew at 16-37 °C (optimum, 28 °C) and pH 6-10 (optimum, pH 7). Strains 1AS11 T , 1AS12 and 1AS13 were not able to grow at NaCl concentrations higher than 0.6 %. Detailed phenotypic and biochemical data for the R. acaciae strains are given in Table 3. The strains can be distinguished from their most closely related Rhizobium species by their ability to use trehalose, turanose, raffinose, lactose, melibiose, methyl β-d-glucoside, N-acetyl-d-glucosamine, N-acetyl-β-d-mannosamine, α-d-glucose, d-mannose, d-galactose, fucose, l-rhamnose, d-arabitol and myo-inositol as sole carbon sources; the strains showed weak positive enzymatic reactions for cystinol-arylamidase, α-mannosidase and β-fucosidase and negative reactions for N-acetyl-β-glucosaminase. Strains are resistant to 10 µg ml -1 kanamycin and 10 µg ml -1 streptomycin, but sensitive to lincomycin and rifamycin. The major fatty acid of the type strain 1AS11 T is C 18 : 1 ω7c with 57.81 % content.

The type strain of Rhizobium acaciae sp. nov. is 1AS11 T (=DSM 113913 T =ACCC 62388 T ), which was isolated from root nodules of Acacia saligna grown in Borj Cedria, a city in Ben Arous governorate, Tunisia. The G+C content of 1AS11 T is 60.82 mol% and the genome size is approximately 8.01 Mb.

Fig. 1 .

 1 Fig.1. Maximum-Likelihood-based phylogenetic analysis of recA-atpD-gyrB-glnII concatenated gene sequences (1734 nucleotides). The three novel strains are in bold. Bootstrap values ≥50 are indicated for each node (1000 replicates). After species name, the strain designation is given followed by the NCBI accession number of the sequence used. The scale indicates the number of substitutions per site.

Fig. 2 .

 2 Fig. 2. Unrooted maximum-likelihood phylogenetic tree based on UBCGs (concatenated alignment of 92 core genes) inferred using RAxML-ng with the GTR +CAT model. Percentage bootstrap values are given at branching points. Bar, 0.005 substitution per position.

Fig. 3 .

 3 Fig.3. Maximum-likelihood phylogenetic tree based on UBCGs (concatenated alignment of 92 core genes) of strains of Rhizobium acaciae sp. nov. and representatives of the 18 genomospecies proposed by Young et al.[START_REF] Young | Defining the Rhizobium leguminosarum species complex[END_REF]. Tree was inferred using RAxML-ng with the GTR +CAT model. Percentage bootstrap values are given at branching points. Strains of R. acaciae sp. nov. are affiliated with genomospecies j. Letters in bold denote the genomospecies proposed by Young et al.[START_REF] Young | Defining the Rhizobium leguminosarum species complex[END_REF] .

Table 1 .

 1 Basic statistics of whole-genome sequences of the three strains of Rhizobium acaciae sp. nov, sequenced using Illumina NovaSeq 6000 technology

	Description

Table 2 .

 2 Digital DNA-DNA hybridiziation (dDDH), average nucleotide identity (ANI) and blast-based average nucleotide identity (ANIb) values among Rhizobium acaciae sp. nov. AS11 T (type strain) and related Rhizobium species

	Rhizobium species	dDDH	ANI	ANIb
	Rhizobium acaciae sp. nov. 1AS11 T (JAPCZO01)	100	100	100
	Rhizobium acaciae sp. nov. 1AS13 (JAPCZM01)	100 (0)	99.99	99.97
	Rhizobium acaciae sp. nov. 1AS12 (JAPCZN01)	90.7 (0.0114)	98.84	98.72
	Rhizobium indicum JKLM 12A2 T (CP054021)	60.0 (0.0515)	94.95	94.58
	Rhizobium laguerreae FB 206 T (MRDM01)	56.1 (0.0588)	94.08	93.19
	Rhizobium changzhiense WYCCWR 11279 T (JABFCQ01)	53.8 (0.0634)	93.68	93.08
	Rhizobium sophorae CCBAU 03386 T (JABFCN01)	53.2 (0.0645)	93.59	92.50
	Rhizobium ruizarguesonis UPM 1133T (PQIG01)	52.7 (0.0656)	93,52	92,27
	Rhizobium leguminosarum DSM 106839 T (JACHFX01)	49.1 (0.0737)	92.67	91.34
	Rhizobium indigoferae CCBAU 71042 (JABFCO01)	49.0 (0.0740)	92.66	91.57
	Rhizobium trifolii DSM 30141 T (JACJHV01)	49.2 (0.0736)	92.60	91.48
	Rhizobium anhuiense CGMCC 112621 T (BMFI01)	42.5 (0.0915)	91.07	89.97
	Rhizobium acidisoli FH23 T (CP034998)	37.3 (0.1090)	89.50	88.79
	Rhizobium redzepovicii 18T T (JAILYH01)	36.5 (0.1123)	88.91	87.60
	Rhizobium hidalgenense FH14 T (LODW01)	35.9 (0.1146)	88.68	87.16

Table 3 .

 3 Phenotypic results on Biolog GENIII MicroPlatesStrains: 1AS11 T ; 2, 1AS12; 3, 1AS13; 4, Rhizobium indicum JKLM 12A2 T ; 5, Rhizobium laguerreae FB206 T ; 6, Rhizobium changzhiense WYCCWR 11279 T . +, Positive; -, negative; w, weakly positive.

			Rhizobium acaciae sp. nov.
	Biolog substrate	1	2	3	4	5	6
	Trehalose	+	+	+	w	-	-
	Sucrose	-	-	-	+	-	-
	Turanose	+	+	+	w	-	-
	Raffinose	+	+	+	-	-	-
	Lactose	+	+	+	-	-	-
	Melibiose	+	+	+	-	+	-
	Methyl β-d-glucoside	+	+	+	-	+	+
	N-Acetyl-d-glucosamine	+

Table 2

 2

			Rhizobium acaciae sp. nov.
	Biolog substrate	1	2	3	4	5	6
	α-Keto-butyric acid	-	-	-	-	-	+
	Acetoacetic acid	-	-	-	-	-	+
	Propionic acid	-	-	-	-	-	+
	Acetic acid	-	-	-	w	-	+
	Formic acid	-	-	-	-	-	+
	Chemical sensitivity
	pH 6	+	+	+	-	-	-
	pH 5	+	+	+	-	-	-
	NaCl 1%	-	-	-	-	+	-
	Antbiotic resistance
	Rifamycin	-	-	-	-	-	+
	Lincomycin	-	-	-	-	-	+
	Kanamycin	+	+	+	NA	-	-
	Streptomycin	+	+	+	NA	-	-
	API ZYM
	Alkaline phosphomonoesterase	-	-	-	-	-	w
	Esterase	-	-	-	NA	-	w
	Cystinol-arylamidase	w	w	w	NA	+	+
	N-Acetyl-β-glucosaminase	-	-	-	NA	-	+
	α-Mannosidase	w	w	w	NA	+	+
	β-Fucosidase	w	w	w	NA	+	+

). R. indicum JKLM 12A2 T showed the highest dDDH of 60.0 % (cut-off, 70 %) and ANIb and ANI values of 94.58 and 94.95 % (cut-off, 96.00%) with strain 1AS11 T followed by R. laguerreae FB206 T with values of 56.10, 93.19 and 94.08 % (Table

2

), all below the respective

Table 3 .

 3 Continued

Table 4 .

 4 Fatty acid composition (%) of 1AS11 T and its related Rhizobium type strains Strains: 1, 1AS11 T ; 2, Rhizobium indicum JKLM 12A2 T ; 3, Rhizobium laguerreae FB206 T ; 4, Rhizobium changzhiense WYCCWR 11279 T . -, Not detected.

	Fatty acid	1	2	4	4
	C 15 : 0 3OH	0.27	-	-	-
	C 17 : 0	0.78	-	-	-
	C 17 : 1 ω8c	0.26	-	-	-
	C 17 : 1 ω6c	0.1	-	-	-
	C 17 : 0 3OH	0.16	-	-	-
	C 17 : 1 anteisoω9c	0.32	-	-	-
	C 18 : 1 ω9c	0.6	-	-	0.5
	C 18 : 1 ω7c 11-methyl	13.24	1.8	1.9	-
	C 20 : 1 ω7c	0.45	-	-	-
	C 20 : 2 ω6,9c	0.17	-	-	-
	Summed feature 8*	57.81	68	69.3	74.9

*Summed feature 8: C 18 : 1 ω7c.

Acknowledgements

All contributions made by members of the Centre of biotechnology of Borj Cedria are sincerely appreciated.

Funding information

This study was funded by the PHC Maghreb project (34MAG21) and the Tunisian Ministry of Higher Education and Scientific Research. The contribution of James T. Tambong was funded by Agriculture and Agri-Food Canada through projects J-002272 and J-002295.

Conflicts of interest

The authors declare that there are no conflicts of interest.


Andres Rivas

Primerica Rahul Verma

Antonio Rodriguez

Pedro H Albuquerque

The Increasing Impact of Spain on the Equity Markets of Brazil, Chile and Mexico

Keywords: JEL classification codes: G15, O54, C22 Emerging markets, Latin America, Spain, Stock markets interdependence, VAR modeling

The article examines stock index price responses in Brazil, Chile and Mexico to those in the US, Spain and four European countries during three sub-periods surrounding the neoliberal reforms of the 1990s: 1988 to 1994, 1995 to 1998, and 1999 to 2004, using VAR modeling. It finds that equity markets became more interconnected as countries opened to international trade and capital flows, and that there was an increasing impact of Spain on Latin American equity markets. Stronger economic linkages (more trade and foreign direct investment) between Spain and these countries, specially in Brazil, seem to explain increased equity markets interconnectedness.

Introduction

Sanchez [START_REF] Valle | A Cointegration Analysis of Latin American Stock Markets and the U.S[END_REF] and Soydemir (1998) point out that, during the 1990s, Latin American markets have become increasingly attractive to investors since they provided high rates of return and had high prospects for economic growth. Given the significance of Latin American equity markets for investors, there has been a substantial body of literature that has examined different issues, among them, the effects originating from the US market [START_REF] Soydemir | International transmission mechanism of stock market movements: evidence from emerging equity markets[END_REF]Meric et al. 2001a[START_REF] Meric | Co-movements of US and Latin American equity markets before and after the 1987 crash[END_REF][START_REF] Ratanapakorn | Interrelationships among regional stock indices[END_REF]; increased interdependence [START_REF] Ratner | Causality tests for the emerging markets of Latin America[END_REF][START_REF] Choudhry | Stochastic trends in stock prices: evidence from Latin American markets[END_REF][START_REF] Meric | Co-movements of Latin American equity markets[END_REF][START_REF] Christofi | Correlation in price changes and volatility of major Latin American stock markets[END_REF][START_REF] Pagan | On the linkages between equity markets in Latin America[END_REF][START_REF] Chen | Stock market linkages: evidence from Latin America[END_REF][START_REF] Pretorius | Economic determinants of emerging stock market interdependence[END_REF][START_REF] Johnson | Economic integration and stock market comovement in the Americas[END_REF]; macroeconomic spillovers [START_REF] Bailey | Exchange rate fluctuations, political risk, and stock returns: some evidence from emerging market[END_REF][START_REF] Bilson | Selecting macroeconomic variables as explanatory factors of emerging stock market returns[END_REF][START_REF] Adrangi | Dynamic relationship between equity prices and macroeconomic conditions: evidence from emerging markets[END_REF][START_REF] Verma | Are emerging equity markets responsive to cross-country macroeconomic movements? Evidence from Latin America[END_REF]; economic asymmetries [START_REF] Pagan | Response asymmetries in the Latin American equity markets[END_REF]; US bond market effects [START_REF] Soydemir | The impact of the movements in USA three months treasury bill yields on the equity markets in Latin America[END_REF]; volatility spillovers [START_REF] Ortiz | Heteroskedastic behavior of the Latin American emerging stock markets[END_REF]; contagion [START_REF] Calvo | Capital flows to Latin America: is there evidence of contagion effects?[END_REF]Bazdresch and Werner 2000); increased integration among regional market indices [START_REF] Ratanapakorn | Interrelationships among regional stock indices[END_REF]; and increased integration among global and regional indices [START_REF] Barari | Equity market integration in Latin America: A time-varying integration score analysis[END_REF]).

The literature indicates that Latin American equity markets are driven by global and local risk factors. In particular, the US market and local macroeconomic variables are the most important factors respectively. However, an important area that has been less studied is the investigation of the influence of European stock markets on Latin American markets, in particular Spain in relation to Brazil, Chile, and Mexico, during the period of the neoliberal reforms of the 1990s. One can expect such relationship because of the following factors: first, there was substantial growth in the bilateral trade between Europe and Latin America during the 1990s [START_REF] Yeyati | Implications of the euro for Latin America's financial and banking systems[END_REF]Europa 2005); second, privatization policies pursued by Latin American countries led to a significant increase in foreign direct investments (FDI) in the region, specially by European countries [START_REF] Hawkins | The banking industry in the emerging market economies: competition, consolidation and systemic stability-an overview[END_REF]Bubel and Skelton 2002); third, during the 1990s, capital flows into Latin America from Europe steadily increased due to low rates of return in Europe [START_REF] Verner | The euro and Latin America[END_REF][START_REF] Yeyati | Implications of the euro for Latin America's financial and banking systems[END_REF].

Because all these are important determinants of international stock market linkages, the 1990s should be marked by significant co-movements between Latin American and European stock prices.

The original contribution of this article is that, unlike previous studies that have compared the role of the US and European markets, such as in [START_REF] Rivas | Are European Stock Markets Influencing Latin American Stock Markets?[END_REF], we concentrate our analysis on the impacts originating from the Spanish stock market, even if alongside other European markets, and refine it by using VAR modeling. This allows for a more careful examination of the structural breaks that happened during three sub-periods: 1988 to 1994, 1995 to 1998, and 1999 to 2004. We also refine previous results by identifying the Latin American markets that were the most affected by the Spanish market. For example, does Mexico respond similarly to Brazil and Chile to shocks originating from Spain? Among other results, the impulse response functions generated from vector autoregression (VAR) models suggest that Latin American stock markets were responsive, with varying degrees of magnitude, to movements in the stock market of Spain. In addition, there were significant differences in the response of these markets during different sub-sample periods.

The paper is organized as follows: section 2 provides a description of the connections between Latin America and Europe. Section 3 describes the theories of stock market interconnectedness. Section 4 presents the empirical results based on the estimated VAR models, and the analysis of these results. Finally, Section 5 offers concluding remarks.

Economic interconnections between Latin America and Europe

As discussed in [START_REF] Dornbusch | Contagion: how it spreads and how it can be stopped[END_REF], international trade is one of the major channels through which a crisis in one economy can affect the economic pillars of other economies. A measure of market interconnectedness is the contemporaneous correlation between countries' output growth rates, based on the theory that trade linkages transmit economic activity from one country to another. If two countries experience output comovements, then cash flows should also move together, and so will their equity markets [START_REF] Phylaktis | Measuring financial and economic integration with equity prices in emerging markets[END_REF]. This mechanism has been confirmed in the long-run by empirical studies that find a positive relationship between output and stock prices [START_REF] Schwert | Stock returns and real activity: A century of evidence[END_REF][START_REF] Roll | Industrial structure and the comparative behavior of international stock market indices[END_REF] for the US, and Canova and De Nicolo 1995, for European countries).

Therefore, increasing economic and financial interdependence among European and Latin American countries was expected to rise in the 1990s, as Europe, and in particular some EU members such as Spain, became increasingly important as a source of capital inflows to Latin America [START_REF] Yeyati | Implications of the euro for Latin America's financial and banking systems[END_REF], and also as trade connections between the two regions have deepened (Europa 2005).

As shown in [START_REF] Rivas | Are European Stock Markets Influencing Latin American Stock Markets?[END_REF] The literature consensus is that the neoliberal reforms of the 1990s led to an increase in the supply of foreign direct investment and capital. There was a significant rise in European foreign direct investment in Latin America, for example, it rose from US$ 31,179 million to US$73,915 million between 1996 and[START_REF] Verner | The euro and Latin America[END_REF] In large part, this was the result of privatization programs, starting with industrial sectors and subsequently moving to service sectors (Europa 2005). Among all European countries, and since 1995, Spain contributed to 45% of total FDI, followed by the US (32%), France, Portugal, UK, Canada and Italy. The banking industry was one of the most exposed to FDI after the structural reforms. The market share of foreign banks in Latin America rose from 7% in 1990 to 40% in 2000 [START_REF] Hawkins | The banking industry in the emerging market economies: competition, consolidation and systemic stability-an overview[END_REF], Mexico being the country with the largest participation of foreign banks in its financial sector (Bubel and Skelton 2002).

The rise of Europe as a source of foreign investment in Latin America was a consequence, among other factors, of the need of most European banks to diversify their portfolios. For European investors, Latin American countries were a potentially profitable and still unexploited destination for their investments. Investment fund managers in Europe had to confront an aging population seeking always higher rates of return, and responded by increasing their investments in developing economies. Pension funds and insurance companies allocated a large share of their portfolios towards Latin American countries in order to diversify their risks [START_REF] Verner | The euro and Latin America[END_REF]. The stock of European investment in Latin America and the Caribbean continued to increase, and by the early 2000s it accounted for more than EUR 200 billion (Europa 2005).

Higher integration among European financial markets also contributed to the search for diversification, as correlations among assets in Europe increased [START_REF] Soydemir | International transmission mechanism of stock market movements: evidence from emerging equity markets[END_REF][START_REF] Yeyati | Implications of the euro for Latin America's financial and banking systems[END_REF]. In conclusion, different factors during the 1990s led European investors to allocate higher amounts of funds into Latin American assets.

Empirical methodology

In order to investigate equity price comovements, we created a database of closing prices of indices from Spain, Italy, Germany, France, and UK, and from Brazil, Chile, and Mexico. We also included US stock market prices as a control variable.

Stock indices are represented by the Bovespa in Brazil, the general price index (IGPA) in Chile, the IPC price index (BOLSA) in Mexico, the Madrid SE price index in Spain, the Milan MIB Storico price index in Italy, the DAX Industrial price index in Germany, the CAC 40 price index in France, the FTSE100 in the United Kingdom, and the S&P500 composite price index in the US.

We choose Brazil, Mexico, and Chile because they were at that time part of the group of the top 30 developed and emerging markets in the world, ranked 18 th , 25 th , and 30 th respectively (IFC 1999). We selected the European countries that are known to have the strongest economic connections with the chosen Latin American countries (International Monetary Fund 1999).

The data set ranges from January 4, 1988, to December 8, 2004, resulting in 778 observations. Data is represented as weekly percentage returns (log P t -log P t-1 ) , where P t is the value of the index at time t in terms of the local currency [START_REF] Tsay | Impact of the Asian Financial Crisis on Latin America[END_REF]. We define the three sub-sample periods based on the timing of the different types of Latin American economic and financial crises that happened during the observation period [START_REF] Kaminsky | Financial crises in Asia and Latin America: Then and now[END_REF][START_REF] Edwards | Contagion[END_REF], Gelos and Sahay 2000and UN 1998). The chosen sub-sample periods are hence January 1988 to December 1994, January 1995 to December 1999, and January 2000 to December 2004.

Firstly, the sub-sample period of January 1988 to December 1994 was marked by currency and banking crises and hyperinflation in Brazil. Secondly, the sub-sample period of January 1995 to December 1999 saw the financial crisis that started in Thailand (1997) and spread across Asian countries with consequences for Latin American countries, and the Russian crisis of 1998 that also impacted Latin America. Finally, during the sub-sample period of January 2000 to December 2004 there was the creation of the euro as the currency of Europe.

Descriptive statistics of the continuously compounded returns are given in Table 1. As expected, higher return rates tend to be associated with higher volatility, and volatility tends to be higher among Latin American economies.

[Table 1 about here] To address the robustness of our estimations, we conducted unit root tests to analyze the time series properties of the data. Table 2 reports the results of the unit root tests for the variables using the Augmented Dickey-Fuller (ADF) test (Dickey andFuller 1979, 1981;[START_REF] Enders | Applied econometric time series[END_REF]. For the ADF test, we reject the null hypothesis of non-stationary series of stock market returns. Given that the log of first differences of all the series is stationary, we estimated the model in log of first differences. This procedure guaranteed series with non-unit roots and thus eliminated the possibility of running into spurious relationships.

[Table 2 about here] We used a VAR model to test for the presence or absence of a stock market response to changes in European stock markets [START_REF] Sims | Macroeconomics and reality[END_REF]). The VAR model is appropriate when estimating unrestricted reduced-form equations with a uniform set of dependent variables as regressors. This model is useful for analyzing possible linkages that might exist between Latin American and European markets, since it does not impose a priori restrictions on the structure of the system and can be viewed as a flexible approximation to the reduced-form of the correctly specified but unknown structural model.

The VAR model can be expressed as:

z (t )=C+ ∑ s=1 m A (s ) z (t -s)+e (t )
where z(t) is a column vector of stock market returns for the three periods of the study, C is the deterministic component comprised of a constant, A(s) is a matrix of coefficients, m is the lag length and e(t) is a vector of random error terms.1 [START_REF] Sims | Macroeconomics and reality[END_REF] suggests that autoregressive systems like these are difficult to describe concisely. It is difficult to explain them only by examining the coefficients in the regression equations. Additionally, [START_REF] Enders | Applied econometric time series[END_REF] argues that the t-tests on individual coefficients are not reliable and do not uncover the most important relationships among the variables. In that sense, [START_REF] Sims | Macroeconomics and reality[END_REF] recommends the analysis of the system's response to random innovations, i.e., IRFs. Thus, we construct IRFs for the VAR models to investigate the response of one variable to a one standard deviation innovation in another variable in the system, which can be thought of as a dynamic multiplier representation. The effects of these innovations can then be orthogonalized using Cholesky decomposition [START_REF] Runkle | Vector autoregressions and reality[END_REF] or generalized impulses [START_REF] Pesaran | Impulse Response Analysis in Linear Multivariate Models[END_REF]. The results based on the Cholesky orthogonalization method may be affected by the choice of variable ordering, so we verify the results using the generalized impulses orthogonalization method, which does not depend on the variable ordering choice.

Since impulse responses are non-linear functions of the estimated parameters, we construct confidence bands around the mean response. Responses are considered statistically significant at the 95% confidence level when the upper and lower bands carry the same sign.

Estimation results

Sub-period January 1988 to December 1994

Figures 1-6 contain the impulse response functions of the Latin American stock market returns in dollars to shocks from European and US stock markets for the sub-sample period of January 1988 to December 1994.2 Figure 1 contains the response of Mexico's stock market to shocks from European stock markets. The graphs in Figure 1 suggest that during this first sub-period of the study, movement in the Mexican stock market seems to be affected by the US and the Spanish stock markets (see Figure 1 a,b). Consistent with the finding of [START_REF] Soydemir | International transmission mechanism of stock market movements: evidence from emerging equity markets[END_REF], we find that there is a positive and significant effect of the US on the Mexican stock market. The response is significant during the first week and becomes insignificant from the second week onward. Unlike [START_REF] Soydemir | International transmission mechanism of stock market movements: evidence from emerging equity markets[END_REF], we also considered the effects of European Markets on Latin America. Our results show that Spain had a positive effect on the Mexican stock market while the effect of the UK market was insignificant. The effect of Spain on the Mexican stock market is positive and significant the first week and becomes insignificant on the second week. However, during the third week becomes significant and then insignificant. Additionally, the graph in figure 1 suggests that movements in France's stock market had a significant effect on the Mexican market during the second week while becoming insignificant thereafter. Lastly, we do not find evidence that the stock markets of the UK, Germany, and Italy had an effect on the stock market of Mexico (see Figure 1 c,d,e). The response of Mexico to the US stock market is a bit higher than to the Spanish market, but much higher than to the French stock market. These findings are consistent with the trade links observed between these economies. The US-Mexico trade links are stronger than those between Spain and Mexico and France and Mexico.

[Figure 1 about here] Figure 2 presents the results based on generalized impulses. In this case, all countries, except for Italy, affect the Mexican market. The Spanish market however presents the most economically significant impact, followed by the US market.

[Figure 2 about here] Figure 3 and 4 contain the impulse response functions of the Brazilian and Chilean stock markets to shocks from the European and US stock markets for the sub-sample period of January 1988 to December 1994. The graph in Figure 3b shows that the Brazilian stock market is affected by shocks in the Spanish stock market during the third week. Additionally, figure 3e suggests that movements in Italy's stock market affected Brazil negatively during the second week. Figure 4a shows that Chile's stock market is affected by shocks from the US stock market. During this period, we did not find evidence that shocks from other European had an effect on the Brazilian and Chilean stock markets.

[Figure 3 was significant during the first week and then became insignificant. However, the response of the Mexican stock market to France is positive and significant during the second week. Note that for this sub-period both the US and Spain had a stronger effect on the Mexican stock market. The same result is obtained based on generalized impulses, as seen in Figure 8, although in this case all European markets present effects on the Mexican market, even if less economically significant than the effects of the US and Spanish markets.

Figure 9 shows the response of the Brazilian stock market to US and European stock markets shocks. Both the US and Spain had a significant effect on the Brazilian market during the first week. Spain, however, also had a significant effect on Brazil during the third week.

Additionally, the dispersion around the mean response of Brazil to shocks from the US and Spain is smaller during this sub-period. The US-Brazil and Spain-Brazil trade links and the foreign direct investment links increased importantly during this period, which may partially explain the difference in response patterns between the first two sub-periods for these countries. Figure 10, based on generalized impulses, also indicates that the US and Spanish markets were the most influential, although all other markets in this case had effects on the Brazilian market.

Figure 11 shows the response of Chile to shocks from the US and European stock markets. Shocks in the US and Spanish stock markets had significant and positive effects on Chile. This response lasted for two weeks and died down afterwards. The Chile-Spain trade and foreign direct investment links are greater than those for Chile and the US during this sub-period, which may partially explain the importance of Spain in the Chilean stock market.

Figure 12 also indicates that, according to the generalized impulses method, the US and Spanish markets had the most economically significant effects on the Chilean market, even if all other markets, except for Italy, also had statistically significant effects.

[Figures 7-12 about here]

Sub-period January 1999 to December 2004

Figures 13-18 contain the Latin American countries' impulse response functions of the stock market returns in dollars to innovations from the European and US stock markets during the sub-period January 1999 to December 2004. Figure 13 contains the response of Mexico's stock market to shocks from the US and European stock markets. Similarly to the previous sub-period, the graphs in Figure 13 suggest that after the implementation of the Euro, the Mexican stock market seems to be affected by movements in the US and Spanish markets (see Figure 13 a,b). The effect of the US on the Mexican stock market is higher than that of Spain, which may be due to the increase trade link between the US and Mexico.

However, an interesting finding for this sub-period is that, despite the fact that the impact of Spain is lower than in the previous sub-period, the dispersion around the mean response of Mexico to an innovation from Spain is also lower (the effects are statistically more significant). Lastly, we do not find that the stock markets of the other European countries had any effect on the stock market of Mexico (see Figure 13 c-f) during the sub-period. The results using generalized impulses shown in Figure 14 however indicate otherwise, with all European markets now affecting the Mexican market with equal strength, maybe as a result of the adoption of the Euro.

Figure 15 contains Brazil's impulse response functions to shocks from the US and European stock markets. The effect of the US and Spain on the Brazilian stock market was positive and significant during the first week while it became insignificant thereafter. The magnitude of the effect of the US was a bit higher than that of Spain, and the dispersion around the mean response of Brazil in this sub-period was smaller. Brazil's response is consistent with the fact that the trade link between Brazil and the US has gotten stronger. Note also that the effect of Spain's stock market on Brazil is higher than in the previous sub-period and that it is statistically more significant, which may be attributed to the fact that both trade between these two countries and Spain's FDI in Brazil became more pronounced during this sub-period. Once again, we found no evidence that the rest of the European markets had any effect on Brazil's stock market during this sub-period (see Figure 15 c-f). On the other hand, the results based on the generalized impulses method (Figure 16) show that European countries were equally important during the period, with effects on Brazil that are in most cases stronger than the effects of the US market.

Figure 17 contains the response of Chile's stock market to shocks in European and American stock markets. The graphs in Figure 17 suggest that movements in Spain and US's stock markets affect Chile's stock market (see Figure 17 a,b). US and Spain stock market effects on Chilean stock market are positive and significant the first week and then become insignificant the second week. This might be accredited to the fact that the trade links with Spain are stronger than during the previous sub-periods. Figure 18, as in the case of Mexico and Brazil, indicates that, based on the generalized impulses method, all European markets affected the Chilean market during the period.

[Figure 13-18 about here]

Conclusion

In this study we employed VAR models to examine the interdependence among equity markets of Latin American countries (Brazil, Chile, and Mexico), the US and European countries during the years surrounding the neoliberal reforms of the 1990s, from January 1988 to December 2004. Three sub-periods were considered : 1988 to 1994, 1995 to 1998, and 1999 to 2004. Each sub-period represents different macroeconomic contexts, as a result of stabilization policies or changes in trade and foreign direct investment flows.

During the first sub-period (January 1988 to December 1994), we found evidence of a significant response of Mexico to the US, Spain, and France. Moreover, during the second sub-period, January 1995 to December 1998, the markets of Spain and France seem to have had an even stronger effect on Mexico than during the first sub-period, and the dispersion effects seem to have gotten smaller. During the last sub-period, January 1999 to December 2004, however, we found evidence of a significantly smaller effect of Spain on the Mexican stock market, and, based on generalized impulses, a tendency of all European markets to become equally important, maybe due to the adoption of the Euro.

In the case of Brazil we found that, in the first and second sub-period of our study, innovations in Spain still produced an effect after two weeks. During the third sub-period we found an even more statistically and economically significant effect of Spain on Brazil. The generalized impulses method indicates, on the other hand, that the effects of most European markets became larger than the effects of the US market during the third sub-period.

In the case of Chile, only the US seems to have had an effect during the first subperiod of the study. None of the European countries had a significant effect on Chile's stock market during the first sub-period. During the second and third sub-periods, however, Spain had a significant impact on Chile's stock market, and, according to the generalized impulses method, all European countries had equally significant impacts after the adoption of the Euro.

Consistent with previous studies, we found that the US stock market had a strong influence on the Latin American stock markets during the three sub-periods under study.

Our findings are consistent with the view that trade links and differences in institutional structures caused emerging markets to respond differently to shocks originating from Europe and the US. For example, Mexico, Brazil and Chile are more responsive to US stock market movements than to European shocks, which can be attributed to the fact that the Latin American economies, and especially Mexico, are more geared towards the US economy. Additionally, during the second and third sub-periods, Spain had much stronger ties with Brazil, which may explain why Brazil responds more strongly to innovations originating from Spain than, for example, Chile.

In conclusion, this study reveals that European stock markets, particularly Spain, seem to have increasingly influenced Latin American markets during the years surrounding the neoliberal reforms of the 1990s. The effects of European markets vary across Latin American markets and time periods. In conclusion, our findings indicate that Latin American trade and financial participation in global affairs changed significantly in nature during the studied period. Response of R_MX to R_US

  , Mexico has the highest trade links with the US among all Latin American countries. The volume of exports and imports of Brazil, Chile, and Mexico to European countries increased significantly from 1990 to 1998, suffered a small declined with the crises of 1998, and increased again up in the early 2000s. Trade between Europe and Mexico rose, but still remained much less important than trade between Mexico and the US. Relatively speaking, trade connectedness between Brazil, Chile and the US is much less important than for Mexico.

  Figures 5 and 6, based on generalized impulses, mostly confirm the results based on Cholesky decomposition, indicating that during this period the Brazilian market was not affected by any other market, and that the Chilean market was affected only by the US market.

Figure 1 .

 1 Figure 1. Response of Mexico to European stock market innovations during 1988-1994

Table 1

 1 Descriptive Statistics of Returns (in local currency) German stock market return (R_GER); French stock market return (R_FR); UK stock market return (R_UK); and US stock market return (R_US). All the variables are in the form of continuously compounded rate of change. The variables in the Augmented Dickey Fuller test are: Brazilian stock market return (R_BR); Chilean stock market return (R_CH); Mexican stock market return (R_MX); Spain market return (R_SPA); Italian market return (R_ITL); German stock market return (R_GER); French stock market return (R_FR); UK stock market return (R_UK); and US stock market return (R_US). All the variables are in the form of continuously compounded rate of change.

	Local
	Currency	Mean Median Maximum Minimum Std. Dev. Skewness Kurtosis
	R_BR	0.0189 0.0101	0.6931	-0.6931	0.1118	0.1179 19.9254
	R_CH	0.0031 0.0024	0.1325	-0.1218	0.0234	0.1195 7.0056
	R_MX	0.0043 0.0058	0.1730	-0.1676	0.0385	-0.1793 4.2786
	R_SPA	0.0014 0.0036	0.0960	-0.1414	0.0271	-0.4277 5.0613
	R_ITL	0.0009 0.0031	0.1058	-0.1153	0.0298	-0.1669 3.8493
	R_GER	0.0011 0.0023	0.1490	-0.1526	0.0311	-0.4847 5.8852
	R_FR	0.0008 0.0009	0.1432	-0.1094	0.0287	-0.1066 5.0601
	R_UK	0.0009 0.0010	0.0991	-0.0815	0.0216	-0.1294 4.7257
	R_US	0.0016 0.0023	0.0895	-0.1041	0.0213	-0.3559 4.7441
	Brazilian stock market return (R_BR); Chilean stock market return (R_CH); Mexican
	stock market return (R_MX); Spain market return (R_SPA); Italian market return
	(R_ITL);

  Response to Cholesky One S.D. Innovations ± 2 S.E. Figure 13. Response of Mexico to European stock market innovations during 1999-2004 Response to Cholesky One S.D. Innovations ± 2 S.E.Figure 15. Response of Brazil to European stock market innovations during 1999-2004

						Response to Cholesky One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E. Response to Cholesky One S.D. Innovations ± 2 S.E. Response to Cholesky One S.D. Innovations ± 2 S.E. Response to Cholesky One S.D. Innovations ± 2 S.E.
				Response of R_BR to R_US Response of R_BR to R_US Response of R_MX to R_US Response of R_BR to R_US Response of R_CH to R_US Response of R_MX to R_US Response of R_BR to R_US							Response of R_BR to R_SPA Response of R_BR to R_SPA Response of R_MX to R_SPA Response of R_BR to R_SPA Response of R_CH to R_SPA Response of R_MX to R_SPA Response of R_BR to R_SPA
	.03 .04 .04 .05 .016 .04 .04																			.03 .04 .05 .016 .04 .04	.04
	.02 .03 .03 .04 .012 .03 .03																			.02 .03 .04 .012 .03 .03	.03
	.01 .02 .02 .03 .008 .02																			.01 .02 .03 .008 .02	.02
	.01 .02 .02																			.02 .02		.01
	.00 .01 .004 .01																			.00 .01 .004 .01
	.00 .01 .01																			.01 .01		.00
	-.01 -.01 .00 .00 .000 .00																			-.01 .00 .00 .000 .00	-.01
	-.02 -.02 -.01 -.01 -.004 .00 -.01																			-.02 -.01 -.01 -.004 .00 -.01	-.02
	-.03 -.03 -.02 -.02 -.008 -.01 -.02																			-.03 -.02 -.02 -.008 -.01 -.02	-.03
	1 1 1 1 1 1 1	2 2 2 2 2 2 2		3 3 3 3 3 3 3	4 4 4 4 4 4 4		5 5 5 5 5 5	5	6 6 6 6 6 6	6		7 7 7 7 7 7	7	8 8 8 8 8 8	8	9 9 9 9 9 9	10 9 10 10 10 10 10	10	1 1 1 1 1 1	2 1 2 2 2 2 2	3 2 3 3 3 3 3	4 3 4 4 4 4 4	5 4 5 5 5 5 5	6 6 6 6 6	5 6		7 7 7 7 6 7 7	8 8 8 8 8	7 8		9 9 9 9 9 9	8	10 10 10 10 10 10	9	10
				Response of R_BR to R_UK Response of R_BR to R_UK Response of R_MX to R_UK Response of R_BR to R_UK Response of R_CH to R_UK Response of R_MX to R_UK Response of R_BR to R_UK							Response of R_BR to R_GER Response of R_BR to R_GER Response of R_MX to R_GER Response of R_BR to R_GER Response of R_CH to R_GER Response of R_MX to R_GER Response of R_BR to R_GER
	.03 .04 .04 .05 .016 .04 .04																			.03 .04 .05 .016 .04 .04	.04
	.02 .03 .03 .04 .012 .03 .03																			.02 .03 .04 .012 .03 .03	.03
	.01 .02 .02 .03 .008 .02																			.01 .02 .03 .008 .02	.02
	.01 .02 .02																			.02 .02		.01
	.00 .01 .004 .01																			.00 .01 .004 .01
	.00 .01 .01																			.01 .01		.00
	-.01 -.01 .00 .00 .000 .00																			-.01 .00 .00 .000 .00	-.01
	-.02 -.02 -.01 -.01 -.004 .00 -.01																			-.02 -.01 -.01 -.004 .00 -.01	-.02
	-.03 -.03 -.02 -.02 -.008 -.01 -.02																			-.03 -.02 -.02 -.008 -.01 -.02	-.03
	1 1 1 1 1 1 1	2 2 2 2 2 2 2		3 3 3 3 3 3 3	4 4 4 4 4 4 4		5 5 5 5 5 5	5	6 6 6 6 6 6	6		7 7 7 7 7 7	7	8 8 8 8 8 8	8	9 9 9 9 9 9	10 9 10 10 10 10 10	10	1 1 1 1 1 1	2 1 2 2 2 2 2	3 2 3 3 3 3 3	4 3 4 4 4 4 4	5 4 5 5 5 5 5	6 6 6 6 6	5 6		7 7 7 7 6 7 7	8 8 8 8 8	7 8		9 9 9 9 9 9	8	10 10 10 10 10 10	9	10
				Response of R_BR to R_ITL Response of R_BR to R_ITL Response of R_MX to R_ITL Response of R_BR to R_ITL Response of R_CH to R_ITL Response of R_MX to R_ITL Response of R_BR to R_ITL							Response of R_BR to R_FR Response of R_BR to R_FR Response of R_MX to R_FR Response of R_BR to R_FR Response of R_CH to R_FR Response of R_MX to R_FR Response of R_BR to R_FR
	.03 .04 .04 .05 .016 .04 .04																			.03 .04 .05 .016 .04 .04	.04
	.02 .03 .03 .04 .012 .03 .03																			.02 .03 .04 .012 .03 .03	.03
	.01 .02 .02 .03 .008 .02																			.01 .02 .03 .008 .02	.02
	.01 .02 .02																			.02 .02		.01
	.00 .01 .004 .01																			.00 .01 .004 .01
	.00 .01 .01																			.01 .01		.00
	-.01 -.01 .00 .00 .000 .00																			-.01 .00 .00 .000 .00	-.01
	-.02 -.02 -.01 -.01 -.004 .00 -.01																			-.02 -.01 -.01 -.004 .00 -.01	-.02
	-.03 -.03 -.02 -.02 -.008 -.01 -.02																			-.03 -.02 -.02 -.008 -.01 -.02	-.03
	1 1 1 1 1 1 1	2 2 2 2 2 2 2		3 3 3 3 3 3 3	4 4 4 4 4 4 4		5 5 5 5 5 5	5	6 6 6 6 6 6	6		7 7 7 7 7 7	7	8 8 8 8 8 8	8	9 9 9 9 9 9	10 9 10 10 10 10 10	10	1 1 1 1 1 1	2 1 2 2 2 2 2	3 2 3 3 3 3 3	4 3 4 4 4 4 4	5 4 5 5 5 5 5	6 6 6 6 6	5 6		7 7 7 7 6 7 7	8 8 8 8 8	7 8		9 9 9 9 9 9	8	10 10 10 10 10 10	9	10
	Figure 5. Response of Brazil to European stock market innovations during 1988-1994 Figure 7. Response of Mexico to European stock market innovations during 1995-1998
	(Generalized)
						Response to Cholesky One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E. Response to Generalized One S.D. Innovations ± 2 S.E.
				Response of R_CH to R_US Response of R_CH to R_US Response of R_MX to R_US Response of R_BR to R_US Response of R_CH to R_US Response of R_MX to R_US Response of R_BR to R_US						Response of R_MX to R_SPA Response of R_CH to R_SPA Response of R_CH to R_SPA Response of R_MX to R_SPA Response of R_BR to R_SPA Response of R_CH to R_SPA Response of R_MX to R_SPA Response of R_BR to R_SPA
	.008 .008 .04 .05 .016 .04 .05																			.008	.020 .008 .04 .05 .016 .04 .05
	.004 .004 .02 .03 .03 .006 .03 .04 .012 .03 .04																			.004	.010 .015 .004 .02 .03 .03 .006 .03 .04 .012 .03 .04
	.002 .02 .008 .02																					.002 .02 .008 .02
	.000 .01 .02																			.000	.005 .01 .02
	.000 .01 .004 .01																					.000 .01 .004 .01
	-.004 -.004 -.01 -.01 .000 .00 .00 -.002 .00 .00 .01																			-.004	-.005 .000 -.004 -.01 -.01 .000 .00 .00 -.002 .00 .00 .01
	-.008 -.006 -.02 -.02 -.004 -.01 -.01																			-.008	-.010 -.006 -.02 -.02 -.004 -.01 -.01
	1 1 1 1 1 1 1	2 2 2 2 2	2 2	3 3 3 3 3 3 3	4 4 4 4 4	4 4	5	5 5 5 5 5 5	6	6 6 6 6	6 6	7	7 7 7 7 7 7	8	8 8 8 8	8 8	9	10 9 9 9 9 9 9	10 10 10 10 10 10		1	1 2 1 1 1 1 1 1	2 3 2 2 2 2 2 2	3 4 3 3 3 3 3 3	4 5 4 4 4 4 4 4		6 5 5 5 5	5 5 5	7 6 6 6 6	6 6 6	8 7 7 7 7	7 7 7	9	8 8 8 8	8 8 8	10	9 9 9 9	9 9 9	10 10 10 10 10 10 10
				Response of R_MX to R_UK Response of R_CH to R_UK Response of R_CH to R_UK Response of R_MX to R_UK Response of R_BR to R_UK Response of R_CH to R_UK Response of R_MX to R_UK Response of R_BR to R_UK						Response of R_MX to R_GER Response of R_CH to R_GER Response of R_CH to R_GER Response of R_MX to R_GER Response of R_BR to R_GER Response of R_CH to R_GER Response of R_MX to R_GER Response of R_BR to R_GER
	.020 .008 .008 .04 .05 .016 .04 .05																			.008	.020 .008 .04 .05 .016 .04 .05
	.010 .015 .004 .004 .02 .03 .03 .006 .03 .04 .012 .03 .04																			.004	.010 .015 .004 .02 .03 .03 .006 .03 .04 .012 .03 .04
	.002 .02 .008 .02																					.002 .02 .008 .02
	.005 .000 .01 .02																			.000	.005 .01 .02
	.000 .01 .004 .01																					.000 .01 .004 .01
	-.005 .000 -.004 -.004 -.01 -.01 .000 .00 .00 -.002 .00 .00 .01																			-.004	-.005 .000 -.004 -.01 -.01 .000 .00 .00 -.002 .00 .00 .01
	-.010 -.008 -.006 -.02 -.02 -.004 -.01 -.01																			-.008	-.010 -.006 -.02 -.02 -.004 -.01 -.01
	1 1 1 1 1 1 1 1	2 2 2 2 2	2 2 2	3 3 3 3 3 3 3 3	4 4 4 4 4	4 4 4	5	5 5 5 5 5 5 5	6	6 6 6 6	6 6 6	7	7 7 7 7 7 7 7	8	8 8 8 8	8 8 8	9	9 10 9 9 9 9 9 9	10 10 10 10 10 10 10		1	1 2 1 1 1 1 1 1	2 3 2 2 2 2 2 2	3 4 3 3 3 3 3 3	4 5 4 4 4 4 4 4		6 5 5 5 5	5 5 5	7 6 6 6 6	6 6 6	8 7 7 7 7	7 7 7	9	8 8 8 8	8 8 8	10	9 9 9 9	9 9 9	10 10 10 10 10 10 10
				Response of R_MX to R_ITL Response of R_CH to R_ITL Response of R_CH to R_ITL Response of R_MX to R_ITL Response of R_BR to R_ITL Response of R_CH to R_ITL Response of R_MX to R_ITL Response of R_BR to R_ITL						Response of R_MX to R_FR Response of R_CH to R_FR Response of R_CH to R_FR Response of R_MX to R_FR Response of R_BR to R_FR Response of R_CH to R_FR Response of R_MX to R_FR Response of R_BR to R_FR
	.020 .008 .008 .04 .05 .016 .04 .05																			.008	.020 .008 .04 .05 .016 .04 .05
	.010 .015 .004 .004 .02 .03 .03 .006 .03 .04 .012 .03 .04																			.004	.010 .015 .004 .02 .03 .03 .006 .03 .04 .012 .03 .04
	.002 .02 .008 .02																					.002 .02 .008 .02
	.005 .000 .01 .02																			.000	.005 .01 .02
	.000 .01 .004 .01																					.000 .01 .004 .01
	-.005 .000 -.004 -.004 -.01 -.01 .000 .00 .00 -.002 .00 .00 .01																			-.004	-.005 .000 -.004 -.01 -.01 .000 .00 .00 -.002 .00 .00 .01
	-.010 -.008 -.006 -.02 -.02 -.004 -.01 -.01																			-.008	-.010 -.006 -.02 -.02 -.004 -.01 -.01
	1 1 1 1 1 1 1 1	2 2 2 2 2	2 2 2	3 3 3 3 3 3 3 3	4 4 4 4 4	4 4 4	5	5 5 5 5 5 5 5	6	6 6 6 6	6 6 6	7	7 7 7 7 7 7 7	8	8 8 8 8	8 8 8	9	9 10 9 9 9 9 9 9	10 10 10 10 10 10 10		1	1 2 1 1 1 1 1 1	2 3 2 2 2 2 2 2	3 4 3 3 3 3 3 3	4 5 4 4 4 4 4 4		6 5 5 5 5	5 5 5	7 6 6 6 6	6 6 6	8 7 7 7 7	7 7 7	9	8 8 8 8	8 8 8	10	9 9 9 9	9 9 9	10 10 10 10 10 10 10
	Figure 2. Response of Mexico to European stock market innovations during 1988-1994 Figure 4. Response of Chile to European stock market innovations during 1988-1994 Figure 6. Response of Chile to European stock market innovations during 1988-1994 Figure 8. Response of Mexico to European stock market innovations during 1995-1998 Figure 10. Response of Brazil to European stock market innovations during 1995-1998 Figure 12. Response of Chile to European stock market innovations during 1995-1998 Figure 14. Response of Mexico to European stock market innovations during 1999-2004 Figure 16. Response of Brazil to European stock market innovations during 1999-2004
	(Generalized) (Generalized) (Generalized) (Generalized) (Generalized) (Generalized) (Generalized)

Response to Generalized One S.D. Innovations ± 2 S.E. Figure 3. Response of Brazil to European stock market innovations during 1988-1994 Figure 9. Response of Brazil to European stock market innovations during 1995-1998.

Figure 11. Response of Chile to European stock market innovations during 1995-1998

After conducting lag-length tests based on the Akaike information criteria and the Schwartz Bayesian criteria and taking into consideration the number of data points and the loss of degrees of freedom, the appropriate number of lags to be included in the model was found to be equal to two.

The Cholesky decomposition ordering is: US, Spain, UK, Germany, Italy and France.

Funding

The project leading to this publication has received funding from the French government under the "France 2030" investment plan managed by the French National Research Agency (reference: ANR-17-EURE-0020) and from Excellence Initiative of Aix-Marseille University -A*MIDEX.

Data Availability Statement

The dataset analyzed during the current study is publicly available in the OSF repository: https://osf.io/t64nx/files/osfstorage/63122c4cdb9397048c11e80e

Conflict of Interest Statement

The authors have no competing interests to declare that are relevant to the content of this article.


Alexandre Ferrere

Bombs, Shapes and Sounds: A joint analysis of Gregory Corso's "Bomb" and Allen Ginsberg's "Hum Bom!"

Keywords: Beat Generation, Poésie de guerre, Poésie visuelle, Poésie sonore, Contreculture Beat Generation, War Poetry, Visual Poetry, Sound Poetry, Counter-culture The

Ce travail se propose d'étudier deux oeuvres d'écrivains de la Beat Generation : « Bomb » de Gregory Corso et « Hum Bom! » d'Allen Ginsberg. Bien que tous deux soient construits autour d'une variation thématique sur la bombe, ils utilisent deux stratégies poétiques différentes. Le premier est un poème visuel, prenant la forme d'un champignon nucléaire, tandis que le second est un poème sonore dans lequel est développé tout un travail sur le son et le rythme. Cet article analyse ces deux stratégies différentes mais complémentaires qui se retrouvent au coeur du travail et de la philosophie de chaque poète et explore ces dimensions ajoutées ainsi que leurs fonctions et expérimentations poétiques respectives.

1950s, can be described as a direct product of World War II. Their works are indeed characterized by a quest for freedom, equality and awareness, partly as a response to the horrors of the war. This influential group also took part in a long-time and virulent anti-war activism as can be seen in the works of artists orbiting around this wide group such as the painting/installation created by Wally Hedrick titled The War Room, The Revolutionary Letters of Diane di Prima, the lyrics of Ed Sanders' band The Fugs, Tuli Kupferberg's humorous book 1001 Way to Beat the Draft or Lawrence Ferlinghetti's broadside "Where is Vietnam?". In that context, two poems stand out for the new dimensions they add to the written word and by summoning the readers' senses participation: Gregory Corso's mushroom-shaped poem "Bomb" and Allen Ginsberg's heavily cadenced piece 'Hum Bom!". Arguing that both poems are transgressing and expanding poetical conventions, this paper is thus an exploration of these two bomb-themed poetical works, with a particular focus on the stress and tensions the two poets worked with in their respective compositions. Beginning with Coro's "Bomb" before moving towards a study of Ginsberg's "Hum Bom!", this paper will also underline how the poems' shapes and sounds form the core of both poet's poetical and political stances.

Gregory Corso, often called the fourth member of the Beat Generation along with Jack Kerouac, William Burroughs and Allen Ginsberg, played an important and distinctive part in the poetical field by the end of the fifties. After a rough start in life, including incarcerations where he discovered poetry, he set himself up in Paris, in a seedy nameless hotel he called himself the Beat Hotel (Miles 2002, 106) where he composed his poem "Bomb"-first edited as a broadside by Lawrence Ferlinghetti for City Lights (Skau 2005, 72) and then published as a foldout in Corso's third poetry collection The Happy Birthday of Death. One striking feature of this particular poem is its shape-a feature that was of utmost importance for Corso who wanted his poem to be printed on a single sheet to make it look like a mushroom cloud (Corso 2003, 111), a shape easily and immediately recognizable, echoing the design of the book's cover. Corso was confronted to formatting problems for the publication of his poem, writing for example "NO MAGAZINE WOULD PRINT IT AS I wanted" in a letter (138) and suggesting that he should print it himself in order to obtain the mushroom cloud he had in mind (111). Another example of the importance of poem's shape is Ferlinghetti's letter in which he accepted to print it as a broadside and included a sketch suggesting the overall mushroom form the poem should take once published (Columbia 2010). All those elements point to the central importance of shape for Corso's poem: a reference to the global context of nuclear threats-"America first with the bomb" Corso would write in 1963, ironizing on the nationalist slogan (Corso 2003, 335)-but also to his immediate environment at the time he composed this poem.

On September 2 nd , 1958, Corso wrote to poet Peter Orlovsky, who was also Allen Ginsberg's lover, about his time in Paris: Dear Peter, Paris in an uproar. Arabas FLN have taken to war in city, they have in past week killed ten cops and four soldiers (mostly on dark streets and in Metros). Yesterday they blew up around here and killed nine. (Corso 2003, p. 136) He would also write a letter to Donald Allen on the same day, detailing the dreadful situation ("Paris teeming with war. Arabs killing police and soldiers and blowing up cafes") (136), and would also describe his terrifying experience in Paris in a similar letter to Ferlinghetti:

Paris is boiling with trouble, Arabas have placed their war here. Last night cafe a block away blown up, dead nine. They are killing soldiers in Metros, and many police. (136) And with this poetic gesture, Corso also placed himself in the tradition of pattern poetry, defined as the harmony between the meaning of words and their physical representations; the most famous example is George Herbert's "Easter Wings" published in 1633, and later Guillaume Apollinaire would give his pattern poems the name of calligrams. Though pattern poems originally use geometric figures,1 the mushroom shape gives a stronger impact to the poem's ideas and visually builds the reality of the bomb's threat. To a certain extent and because of the importance of form in Corso's poem and its theme, "Bomb" can be compared with Filippo Tommaso Marinetti's work "A Tumultuous Assembly" composed after World War I. Indeed, besides the fact that both have been produced after a war, both focus on the interplay between words and their representations on the page. But while the Italian futurist deconstructs, Gregory Corso reconstructs a representation of war. Considering words as more than words, using them as raw materials to build a physical and symbolic representation in a context of war was also practiced by other poets, such as e.e. cummings who worked on the typographic aspect of poetry in his war poems like "a Woman". In fact, just like Rick Rylance stated in War Poetry, "modern approaches to familiar problems adjust our sense of their importance" (Featherstone xiii), and Corso did just that: he pushed his readers to see and feel a physical representation of a new but familiar threat.

But what is even more interesting with Corso's "Bomb" is his deliberate choice to represent a mushroom cloud as a poem-the paroxysmic symbol of annihilation of existence, of the destruction of mankind, and thus of literature, as a literary object. This gesture is a reversal one; Corso hijacked the tradition of pattern poetry which is usually an ode to an object or an animal and dedicated his poem to an anti-poetic but, and this is important, a human, creation. The content of the poem itself seemed to have suffer from the explosion: "grassy clarion air", "marble helmsmen" (Corso 1960, 32-33)… It is as if the explosion had scattered and blended words throughout the mushroom cloud, leaving the poem in a state of confusion and the reader in stunned position. This provocative take on poetry and war goes even further in the language of the poem itself, with the poet addressing directly the bomb in ambiguous lines ("O Bomb I love you") (32)(33) or even showing pity to it ("Poor little bomb") (32-33). Corso's dark humor builds against preconceptions-as a bomb cannot be loved (reminding a famous line from Dr.

Strangelove which would appear six years later)-but also against his peers' conceptions since it seems to go opposite to pacifist notions and anti-war movements. This explains why the audience-consisting of members of the Campaign for Nuclear Disarmament-was shocked when Corso read it in public: "they showed their feelings by removing their shoes and throwing them at Gregory, calling him a fascist" (Miles 2000, 113). Though this story may have been exaggerated, Gregory Corso was indeed insulted and "jeered" (Hugh-Jones); and a review in Time magazine considered the last lines as an example of "Beat Blather" (Kraemer Hoff 211).

But it seems that this part of the audience misunderstood Gregory Corso's point. As he wrote: "A parody really, but they couldn't get it-anyway, it did bug them" (Corso 2003, 105). First, the poem is mostly ironic, as is the antithetical title of the volume, in the same vein as Stephen Crane's poem "War is Kind". For example, Gregory Corso frequently used apostrophe and lyrical pronouns to imitate an ode, like in the line "O Bomb thy BOOM his tomb" (Corso 1960, 32-33). The gap between the language, its musicality and the tricky subject of the poem adds absurdity to the very act of bombing and to the Cold War arms race: the poem, imitating a love poem, is therefore flirting with craziness-Corso sometimes referred to his poem as his "crazy "Bomb" poem" (Corso 2003, 105). Some lines also reveal this surrealist situation, using the power of humor to denounce, as in "I want to kiss your clank eat your boom" (Corso 1960, 32-33) , and avoiding lamentations; a poetic choice he explained:

[…] the only way for me to do this was not to say "O Bomb how terrible you are," but to say "O Bomb I love you, I want to put a wig of goldilocks on your baldy bean, a lollipop in your furcal mouth…" (Corso 2003, 355) Moreover, Corso wrote in one of his letters that the poem is "all about the bomb being lonely and sad because everybody wants to die by cars drowning electric chairs, but not by Bomb" (Corso 2003, 105). The same idea is to be found at the very beginning of the poem in the line "you're no crueler than cancer" (Corso 1960, 32-33); for Corso, death is death and it is already omnipresent. What is more is that, in this poem, the bomb is not to blame because it simply is a human creation, a growth or an extension of knowledge and a mirror of mankind.

For example, a line like "bomb / you are as cruel as man makes you" (32-33) invites the reader to think about who is really to be blamed. Corso is thus pointing at the ambiguity of fearing the bomb but not who created it-and he composed a poem in a mushroom cloud shape to that extent: a product of mankind which, like bombs, is simply a human creation, the main difference being that one is an opening and the other a destruction. This paradoxical situation also echoes Diane di Prima's "the vortex of creation is the vortex of destruction" in her "Revolutionary Letter #12" (20); and Corso's poem seems to bear this motto throughout the lines and the chosen shape, as the creative impulse is crystalized in a destructive shape, and destruction is immortalized in a creative work. This endless mirror effect plays like a kaleidoscope, the form reflecting mankind's potential auto-annihilation, the poetic gestures inviting reflections after reflections, the paradoxical view of the bomb as an artifact to celebrate… As he wrote: "my Bomb poem is a hundred different poems" (Corso 2003, 211). But this poem is not a direct pamphlet against the bomb, offering "no impetus to fight to change the system" according to Christine Hoff Kraemer (211). Corso even stated that this poem was not meant to be neither political nor lampoonist:

If I start with hating it [the bomb], with the hate of it, I get no farther than a piece of polemic, a political poem-which I usually fall flat on. That's not a political poem exactly, that "Bomb" poem". (Miles 2000, 107) On the contrary, the subtlety of the poem is Corso's insistence that the bomb is a creation we all should embrace and welcome, that we must learn to live with it and look into our own creations-according to Corso, we could even laugh at/with it:

That I am unable to hate what is necessary to love That I can't exist in a world that consents A child in a park a man dying in an electric-chair

That I am able to laugh at all things (Corso 1960, 32-33) In other words, if we are to embrace human creations such as a poem, we thus should be welcoming the bomb as part of our own existence-that is to say to avoid the hypocrisy of celebrating the best while hiding the worst, to see them as two sides of the same coin and to accept that they live together: it is "necessary to love" it, there is no escape. Corso declared in this context that the poem's "content is one of love, love for life, love for man" (Corso 2003, 133). This is conveyed by the numerous and various references to scales (from neutrons to the universe), places (from the Bronx to Istanbul), eras (from swords to the bomb) and religions (from Zeus to Buddha).

Though this "love for man" is, as he wrote in his poem, a consequence of his role as a poet (Corso 1960, 32-33), this nevertheless results into a paradoxical feeling of humanity within the idea of the bomb. According to him, he chose to conclude the poem with "bitterness", after struggling between "light or profundity" and "humor", (Corso 2003, 112) because " […] in the hearts of men to come more bombs will be born" (Corso 1960, 32-33). However, the poet admitted in a letter that someday the poem might end in a lighter way (Corso 2003, 112), creating therefore a global and universal poem that would be adaptable as time went by.

Another interesting feature of this poem is that it also plays on sounds, as the last part mimicking explosions with the help of capital letters, onomatopoeias and assonances clearly 1960,[32][33] This tends to demonstrate that two dimensions are at work in Corso's poem: the immediate visual shape and its sonorous quality. In fact, as Gregory Corso put it himself: "when it's read, it's a sound poem" (Miles 2000, 107). As a consequence, not only are the words colliding into one another building the dense mushroom cloud in terms of meaning, but their sounds also provide the poem with a new layer of texture. Corso' poem then invades the reader's sense and perceptions to pervade their minds with a new reflection on the bomb-it is both an explosion of the senses and an explosion of the mind.

The playing on sounds is the main characteristic of Allen Ginsberg's poem "Hum Bom!". 2 Allen Ginsberg is mostly known for his long groundbreaking poem "Howl", as well as for his lifelong anti-war activism. He participated in many public protests, especially against the Vietnam war and, of course, many of his poems convey his active pacifism. One example is from "America" where he addressed America just like Corso did with the bomb: "America when will you end the human war? / Go fuck yourself with your atom bomb" (Ginsberg 154).

In the same poem, Allen Ginsberg already played with sounds and meaning, transforming "Ugh" to "Hah" to a final "Help": That no good. Ugh. Him make Indians learn read. Him need big black Niggers. Hah. Her make us all work sixteen hours a day. Help. (156) But the protest poem "Hum Bom!" appears to deepen Ginsberg's exploration of sound poetry.

This poem has a rather peculiar history as it was written over a twenty-year period: a first part was composed in 1971 (1004-1005), a second one (which was modified in the final version) in 1984 (1005-1007)3 and a last part in 1991 (1007-1008). Furthermore, at least two parts were composed in response to a conflict. The first was written just after Allen Ginsberg visited the Jessore Road refugee camp during the Bangladesh Liberation War (Allen Ginsberg Project 2018) and, according to him, this part "codifies a longer improvisation in a Southern church at an antiwar rally marking U.S. carpet-bombing North Vietnam" (Hoffman 145). The last part is a straightforward reference to the Gulf War, as can be understood from the explicit mentions of Saddam Hussein and George H. W. Bush: It seems that the 1984 part was specifically written for a recording with Elvin Jones, hence the dedication. But this is also the year the New York Times published a blacklist of people banned from "government-sponsored overseas speaking engagements", which included Allen Ginsberg (Miles 2002, 510-512).

Ginsberg's aim in this poem is to mimic the sounds of wars through repetitive lines and the omnipresence of alliterations and assonances; meant to be read out loud-as showed by Ginsberg's own various renditions4 -the poem can therefore be situated more precisely between a performance poem and a sound poem. In fact, the very title sets the mood. First of all, it reveals the importance of sound as an evolutive quality of a word since "Hum Bom!" later becomes "Whom bomb?" in the poem (Ginsberg 1004). This evolution implies that Allen Ginsberg put the emphasis on the very sounds of the words, free from their spellings, to indicate that the phonemic realization of the words is of significance here, perhaps even more than their meanings. The original title chosen for this poem was "Hūṃ Bom!", a spelling which is to be linked with Allen Ginsberg's practice of Buddhism, since it is usually used in mantras like "oṃ maṇipadme hūṃ". During a 1993 reading, Ginsberg also explained: And then the.. continued consideration with a poem I had begun, May 1971, and then added every ten years a new section, based on the Shaivite cry when Shaivite saddhus in India in the burning grounds smoke a chillum of marijuana, they raise a clay pipe to their foreheads and say "HUM BOM!" or "BOM BOM MAHADEV!" (The Allen Ginsberg Project 2017) He also declared in an interview that chanting was a link to yoga and meditation which led to experiments like "Hum Bom!" (Portugés 131). This point is interesting because it blends the horror of war and the calm of meditation, materialistic destruction and spiritual awareness-a mantra being a spiritual tool to be repeated rhythmically and continuously, just like the poet does in this poem. The orality of the poem is also underlined on the page in the spelling of expressions like "whydja", "hadda" or "wanna" (Ginsberg 1007), and in his performances, one can notice that Allen Ginsberg hammers a kind of playful, primitive rhythm that progressively evolves into a more aggressive pattern. Indeed, Ginsberg expands several rhythms, from very distinct accentuated words to violent contractions like "whatdid" or "musta" (1006). In that sense, words like "whom" or "bomb" offer a structural rhythm for the poem which can lead to multiple interpretations, from an angry crowd of striking workers to an ironic and aggressive cheerleading. 5 In fact, the difference between the usual accentuation of a word and Ginsberg's own accentuation led Patrick Dunn to write that "patterns of pitch accent are repeated, often without concern for their pragmatic meaning" (84). The aim of Allen Ginsberg in his readings

  and BOOM ye suns BOOM BOOM ye moons ye stars BOOM nights ye BOOM ye days ye BOOM BOOM BOOM ye winds ye clouds ye rains go BANG ye lakes ye oceans BING Barracuda BOOM and cougar BOOM Ubangi BOOM orangutang BING BANG BONG BOOM bee bear baboon ye BANG ye BONG ye BING (Corso

  still there building a bomb! Saddam's still there building a bomb!(Ginsberg 1007)

"Among the shapes commonly represented in such poems have been axes, eggs, spears, altars, wings, columns, pyramids, diamonds, and other geometric figures."

See:Ginsberg 2006, 577 for the unaltered version.

Bono also performed it a few years ago TheAllen Ginsberg Project. "Hum Bom -(Bono & Juan Felipe Herrera)." The[START_REF] Allen | Hum Bom -(Bono & Juan Felipe Herrera[END_REF]) http://allenginsberg.org/2017/04/hum-bom-april-9/), as well as Ai Weiwei very recently (TheAllen Ginsberg Project. "Hum Bom". Youtube (3 Nov. 2022) https://www.youtube.com/watch?v=FQOn4k90VIk).

A type of poetic construction Ginsberg would also use in his most famous poems like "Howl" or "America" for example, the two poems being written with extensive use of anaphora.

of this poem is mostly on hammering natural sounds, with a focus on emotion, implying that the emotional response to the sounds is more powerful than to the concrete meaning; one of the reasons why this poem evokes sufferings and destructions so strongly without even mentioning them directly. Moreover, and as can be heard in the second part, rhythm is also a fundamental feature of the poem:

Who said bomb? Who said we hadda bomb? (Ginsberg 1006) In the audio version, Allen Ginsberg insisted on the syllabic division of the lines, playing with rhythm. While the first verse in the example above contains three syllables, the second one doubles it. Another interesting example can be found in the first part:

What do we do? You bomb! You bomb them! (1005)

The rhythmic pattern here is almost jazzy, due to a virtual offbeat implied by the first exclamation mark:

What do we do?

The powerful sonorous quality of the poem is thus intrinsically linked to its rhythmic construction, working as a basic structure to convey the idea of war, of bombing and of destruction. Furthermore, it seems that 'Hum Bom!" could be read (or heard) like a modern "Beat! Beat! Drums!", the famous poem written by Walt Whitman:

Beat! beat! drum! -blow! bugles! blow! Through the windows-through doors-burst like a ruthless force, Into the solemn church, and scatter the congregation, Into the school where the scholar is studying; (Whitman 237) At least five elements in this poem are to be found in Ginsberg's "Hum Bom!": a very specific rhythm-Michael Moon speaks of "martial rhythm" (237), a shared emphasis on sounds (for example the alliterations in [b] in the first verse), an extensive use of repetitions and anaphora (like "through" or "into the") as well as of exclamation marks, and a direct bond with the reader/listener.

This last point leads us to the particular use of pronouns in "Hum Bom!". Allen Ginsberg uses two main pronouns in the poem, "we" and "you", and he plays on what these pronouns refer to. Sometimes we understand that they refer to countries or political institutions though sometimes, they refer to individuals against the institutions responsible for the bomb, implying therefore the active participation of the reader/listener. If we take examples from the first and second stanzas, as well as from the third and fourth ones, there is a kind of (distorted) mirror effect between them (Ginsberg 1004-1005): 6

First stanza

Whom bomb?

We bomb'd them!

Second stanza

Whom bomb?

You bomb you!

Third stanza

What do we do?

Who do we bomb?

Fourth stanza

What do we do?

This split reaches a climax in passages where the pronouns "we" and "you" disappear to become "they", as to separate "they" (who are responsible for the wars) from "we" and "you" (the poet and the reader/listener):

They thought they hadda bomb! They thought they hadda bomb! (1006-1007)

But the notion of camp is totally wiped out when it comes to the victims of wars, reinforcing the idea that death knows no boundaries, as shown by the use of pronouns in the following passage:

6 Emphasis mine.

Whom bomb?

We bomb you!

Whom bomb?

You bomb you! (1005) 7

The third part sounds like an aggravation of the bombing in the sense that Ginsberg builds a progressive outburst of apocalyptic sounds and meanings:

Armageddon for the mob

This is no coincidence then that Armageddon is a reference to a well-known biblical prophesied battle between good and evil, and that Gog and Magog-respectively an individual and a place considered as enemies of "the people of God to appear at the end of the historical process" in the Bible ( Then again, "GogMagog" appears to be the bearer of destruction and "desolation"-and knowing the lasting influence of William Blake on Allen Ginsberg's life and poetical erudition, 8

such an intertextual reference tends to insist on the timelessness of the message. This particular poetic construction, both in sound and meaning implies two things. First, it underlines the reality of the conflicts and erases the frontiers between poetry and reality, poetical prophecies and modern politics, which is emphasized not only by the overall war sounds of the poem or the tone of Ginsberg's reading, but also by actual mentions of Saddam Hussein and George H.

W. Bush in the second part of the poem, making them part of an anti-war poem for both the sounds of their names and their political embodiments:

Saddam said he hadda bomb! Bush said he better bomb! Saddam said he hadda bomb! Bush said he better bomb! (Ginsberg 1007) Allen Ginsberg's imaginative creation is thus here a symbol of real wars. Not only does Ginsberg used political leaders as poetic tools to explore the sounds of their names and to underline in the same gesture their responsibilities towards the world as well as the absurdity and danger of such a concentration of destructive powers, but he also placed them on the same apocalyptic level of annihilation with biblical prophecies, blurring the frontier with reality, calling to the readers' and audience's imagination and thus increasing the impact of his messages. Then, it also shows that, as a poet, Allen Ginsberg considered that he had a responsibility (as Hussein and Bush had) regarding wars. To that extent, it is worth noting that Allen Ginsberg's own name appears at the end of the poem, where the incantatory question "who wanteda a bomb?" is partially answered:

8 For more on this topic see:

Ginsberg says Gog & Magog

Armageddon did the job. (Ginsberg 1008) In fact, by including the sounds of his name, as well as Hussein's and Bush's, the poet composed a poetic structure in which names are real incarnations of wars and palpable figures; whether it be Allen Ginsberg denouncing wars or Hussein and Bush making it, they are all taking part in them, their own names being symbolically at the core of the horrors. Those last two lines also introduce the poet in the tradition of the prophetic bard warning the rest of the world, trying to convince us through the power of sounds-and also positioning Ginsberg back in the primitive realm of oral poetry. While this posture of Ginsberg as a poet-prophet is not new in his career, he directly experimented this position when he chose to read this poem during one particular American moment: the ceremonial first pitch of a baseball game. Indeed, invited in 1994 by the Giants to read a poem and throw out the first pitch, Ginsberg delivered his "Hum Bom!" in front of an unusual audience of nearly 30.000 baseball fans. And just like Corso had experienced with his "Bomb", Ginsberg was booed the entire performance-before throwing a "perfect, bounceless first ball" (Miller). Ginsberg told a reporter that he had chosen to read this specific poem for this particular occasion "because it is a sound poem that would echo properly through the stadium and penetrate everybody's skulls" (Miller), underlining his public mission as a poet-prophet.

To a certain extent, Gregory Corso's and Allen Ginsberg's poems can be seen as complementary: while one stresses the visual display of words on the page, the other focuses on the penetrative sound for the ear; Gregory Corso sculpted the page in order to graphically impact the reading process, while Allen Ginsberg gave to words a powerful sound incarnation to evoke wars-giving shape and sounds to ideas. But while both poems are bomb-themed and both of their authors share the same so-called "Beat" label, their poetic and semantical conceptions are very different and unfold in almost opposite directions. Corso's poem, indeed, embraces self-annihilation as part of mankind and contemplates death as an omnipresent, inevitable reality, no matter the form it takes and therefore inversing the usual view on such a process. In that sense, the shape of the bomb acts like a visual shock for the reader and the poem is built from fragment of words, absurd juxtapositions and layers of confusion, reinforcing in return the very shape of the poem and establishing the bomb as a complex postmodern symbol. 9 On the contrary, Ginsberg's poem is an overtly politically-engaged sound pamphlet. And while Corso's "bomb" "den[ies] the agents of destruction both credit and responsibility" as Michael Skau pointed (1999, 131), "Hum Bom!" is a hypnotic, aggressive and sonorous poem denouncing the powerful men of the world who are able to annihilate life in a few seconds.

More than that, Ginsberg placed himself in a bardic tradition, the poet who knows and who warns us about the madness of times. In that sense, the poem's sound variations are working on multiple levels: getting into the heads of the audience with catchy rhythms and an overflow of assonances and alliterations, hammering the ultimate danger of the bomb by imitating war sounds and involving personal responsibilities-both political leaders' and citizens'. In other words, this is an omnidirectional preach addressed to the world, figuratively and literally, asking us to take actions to fight against a global threat. Nevertheless, both poets highlighted an omnipresent component of modern society in their poems and introduce their audience to what constitute a new paradigm in a warfare era: embrace it, or fight it.