Alexandre Darbon

Eugenio Valdano

Chiara Poletto

Armando Giovannini

Lara Savini

Luca Candeloro

Vittoria Colizza

Network-based assessment of the vulnerability of Italian regions to bovine brucellosis

Keywords: Brucellosis, networks, animal trade, vulnerability, epidemic model

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Introduction

Brucellosis is the most common zoonotic disease worldwide, severely hindering livestock productivity and human health [START_REF] Corbel | Brucellosis: an overview[END_REF][START_REF] Pappas | The new global map of human brucellosis[END_REF][START_REF] Ariza | Perspectives for the treatment of brucellosis in the 21st century: the Ioannina recommendations[END_REF][START_REF] Franc | Brucellosis remains a neglected disease in the developing world: a call for interdisciplinary action[END_REF]. Bovines are the natural host for Brucella abortus, the pathogen causing bovine brucellosis, a highly contagious sub-acute and chronic disease leading to abortion, premature births, weak offspring, retained placenta, or infertility [START_REF] Corbel | Brucellosis in humans and animals[END_REF]. Transmission between animals generally occurs by direct contact and environmental contamination following an abortion. The disease is the cause of severe economic losses as a consequence of late term abortion, substantial decline in milk and meat production, reduced fertility, and the induced effects of control strategies such as the loss of infected animals to culling and restrictions in commerce.

Despite the great progress in controlling and eradicating the disease in many areas of the world [START_REF] Pappas | The new global map of human brucellosis[END_REF], there still remain regions where the infection is endemic in livestock. In Europe the vast majority of Member States (19 out of 28, 68%) are currently declared officially free from bovine brucellosis (OBF) [START_REF] Efsa | The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2016[END_REF], following successful eradication campaigns co-financed by the European Union. The disease still persists in the Southern countries close to the Mediterranean basin where it is responsible for the largest notification of infections in humans in Europe, often leading to severe cases requiring hospitalizations. Eradication is dramatically hampered by several factors: the sub-acute nature of the disease that leads to an initial phase following the infection that is often not apparent (silent spreading phase); the lack of specificity of serological tests that may cross-react with other bacteria [START_REF] Fadeel | Comparison of four commercial IgM and IgG ELISA kits for diagnosing brucellosis[END_REF][START_REF] Varshochi | False positive seroreactivity to brucellosis in tuberculosis patients: a prevalence study[END_REF]; the performance of control activities and the lack of full compliance to reporting and regulations in some contexts [START_REF] Calistri | Risk factors for the persistence of bovine brucellosis in Sicily from 2008 to 2010[END_REF][START_REF] Graziani | La brucellosi in Italia dal[END_REF][START_REF] Bronner | Why do farmers and veterinarians not report all bovine abortions, as requested by the clinical brucellosis surveillance system in France?[END_REF].

Italy currently has OBF status for 11 regions and 9 provinces, localized in the center and north of the country [START_REF] Efsa | The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2016[END_REF]. The first eradication strategy was introduced in 1994 through a strict test-and-slaughter policy when the disease was endemic in the entire country (Italian Ministry of Health, 1994), after the discontinuation of animal vaccination. Efficient progress towards eradication was made in the regions of the north and center that progressively gained the OBF status. Despite the continuous and considerable efforts of the veterinary services and the implementation of stricter regulatory policies in 2006 (Italian Ministry of Health, 2006), the southern part still remains affected by the disease with a considerable persistence in the regions of Campania, Calabria, Puglia, and Sicilia (Figure 1) [START_REF] Efsa | The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2016[END_REF].

Previous studies identified important drivers for brucellosis persistence in the affected countries in Europe. Contiguous spread from previous outbreaks was generally identified as the main source of new infections [START_REF] Godfroid | Brucellosis in the European Union and Norway at the turn of the twenty-first century[END_REF]. Pathways for brucellosis spatial transmission in Spain and Northern Ireland were contacts between herds, in particular from pasture rental practices, neighboring herds, or through cattle movements between farms [START_REF] Abernethy | Epidemiology of bovine brucellosis in Northern Ireland between 1990 and 2000[END_REF]Stringer et al., 2008;[START_REF] Dias | Epidemiological situation of bovine brucellosis in the State of Paraná, Brazil[END_REF][START_REF] Abernethy | Epidemiology and management of a bovine brucellosis cluster in Northern Ireland[END_REF][START_REF] Cowie | Shared risk factors for multiple livestock diseases: a case study of bovine tuberculosis and brucellosis[END_REF]. The only study on risk factors for bovine brucellosis in Italy was conducted in the insular region of Sicilia and showed that herd size and beef or mixed production types were associated with higher risk of persistence of the disease in the region [START_REF] Calistri | Risk factors for the persistence of bovine brucellosis in Sicily from 2008 to 2010[END_REF]. The number of animals introduced from other herds instead did not seem to play an important role.

The aim of this study was to quantitatively assess the vulnerability of Italian regions to bovine brucellosis to explain the extremely diverse epidemiological situation reported in the country, with strong regional differences. Adopting a network perspective for veterinary epidemiology and policy assessment [START_REF] Dubé | A review of network analysis terminology and its application to foot-and-mouth disease modelling and policy development[END_REF][START_REF] Martínez-López | Social network analysis. Review of general concepts and use in preventive veterinary medicine[END_REF], we developed a mathematical model describing the spread of bovine brucellosis from farm to farm associated with the movement of infected animals in the region. The model is based on the complete database of daily cattle trade movements for the whole country from January 2006 to December 2012, and it is parameterized with outbreak data reported to the Italian National Veterinary authority in the period 1983-2015. We introduced a measure of vulnerability quantifying the risk for brucellosis persistence in the affected regions, and compared OBF areas with non-OBF areas accounting for premises spatial distribution, trading patterns, farming practices, outbreak status, herd market value, and exploring different epidemic conditions.

Material and Methods

Cattle trade movement data

Data on cattle trade movements were obtained from the Italian National Database for Animal Identification and Registration (NDB) that is managed by the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise (IZSAM) on behalf of the Italian Health Ministry ("Sistema Informativo Veterinario," n.d.). The database details the movements of the entire Italian population of bovines among animal holdings, providing a comprehensive picture of where cattle have been kept and moved within the country. Each movement record reports the unique identifier of the animal, the identifiers of the holdings of origin and destination, and the date of the movement. Holdings are georeferenced.

Here we examined the daily records from January 1, 2006 to December 31, 2012. A total of 11,775,842 bovines were tracked, counting for 3,693,593 recorded displacements among 190,596 animal holdings in Italy (Table 1).

Network-based spatial transmission model

Cattle movements were represented in terms of a network with nodes corresponding to premises, and directed edges representing animal movements between two premises [START_REF] Dubé | A review of network analysis terminology and its application to foot-and-mouth disease modelling and policy development[END_REF][START_REF] Martínez-López | Social network analysis. Review of general concepts and use in preventive veterinary medicine[END_REF]. The static projections of Italian network aggregated over a year were provided by [START_REF] Natale | Network analysis of Italian cattle trade patterns and evaluation of risks for potential disease spread[END_REF], and its dynamical properties considering multiple timescales were assessed in [START_REF] Bajardi | Dynamical Patterns of Cattle Trade Movements[END_REF]Valdano et al., 2015c).

Given the fundamental importance of causality in the sequence of trading links for the transmission of cattle diseases [START_REF] Bajardi | Dynamical Patterns of Cattle Trade Movements[END_REF][START_REF] Vernon | Representing the UK's cattle herd as static and dynamic networks[END_REF], we built the full time-resolved directed weighted network based on daily movement records. We denoted with 𝑊 ! the weighted adjacency matrix representing the network at the daily snapshot 𝑡 in the time period under study. The matrix element 𝑊 !,!" corresponds to the number of animals moved from holding 𝑖 to holding 𝑗 at time 𝑡, and it is equal to zero if no animals are moved.

Since we are interested in the transmission and persistence of brucellosis at the regional level, rather than the detailed dynamics within a single farm, we modeled spatial transmission from farm to farm considering animal holdings as discrete epidemiological units. The spread on the dynamical network was modeled using a simple susceptible-infectious-susceptible (SIS) approach for disease progression [START_REF] Keeling | Modeling Infectious Diseases in Humans and Animals[END_REF] where premises can be in one of the following two states: susceptible (S), if the farm is brucellosis-free, and infectious (I), if the farm experiences a brucellosis outbreak. Transmission may occur from an infected farm 𝑖 to a susceptible one 𝑗 upon trading animals at time 𝑡 with a probability 𝛬 !,!" = 1 -1 -𝜆 ! !,!" , where 𝑊 !,!" counts the number of animals moved and 𝜆 indicates the per-animal risk of transmission. The expressed probability 𝛬 !,!" thus accounts for an increased risk associated to a larger number of traded animals [START_REF] Bajardi | Dynamical Patterns of Cattle Trade Movements[END_REF]Valdano et al., 2015b). An infected farm can clear the infection with rate 𝜇 whose inverse measures the average duration of a brucellosis outbreak in a farm. Once disease-free, the farm recovers the S status and can be infected again with brucellosis, thus experiencing successive outbreaks.

To assess the spatial heterogeneity of the brucellosis epidemiological situation in Italy at the regional level, we considered regional sub-networks of the national cattle trade network, each of them including all premises and all trading links within the region (Table 1).

We also measured basic network indicators for each animal holding: the in-degree of farm 𝑖 counting the number of farms which farm 𝑖 receives cattle from (and similarly for the out-degree counting outgoing links); the in-strength of farm 𝑖 counting the number of incoming animals in the farm (and similarly for the out-strength counting the number of animals moved out of the farm). These quantities can be defined at a given time resolution (e.g. during a day, a week, a month, etc.) [START_REF] Bajardi | Dynamical Patterns of Cattle Trade Movements[END_REF], and here we considered the yearly timescale. We then computed averages and standard deviations for these indicators over the years of the dataset under study, and over all farms in the region (Table 1).

Model parameterization

Data on brucellosis control activities were collected from the Italian National Animal Health Managing Information System, an informatics system developed by IZSAM on behalf of the Ministry of Health to monitor the progress of the eradication plan and measure the degree of achievement of its objectives (Italian Ministry of Health, 2012;"Sistema Informativo Veterinario," n.d.). The database reports on all surveillance and eradication activities and their results at farm and individual animal level. We used records of bovine brucellosis outbreaks occurring in Italy between February 1983 and September 2015. For each outbreak, we considered data reporting the identifiers of the affected animal holding, its production type, and the dates of start and end of the outbreak, based on the date of first infection detection and date of clearing of the infection, respectively.

To account for different regional contexts, we parameterized the transmission model in the brucellosis-affected regions by setting the recovery rate 𝜇 equal to the inverse of the median outbreak duration reported for each region, and listed in Table 2. We also explored fluctuations of this value within the 95% confidence intervals.

Since regions in the center and north of Italy have been OBF for many years, no empirical data exist on the duration of the outbreak. We then parameterized the SIS model in those regions using the average of the outbreak durations reported in brucellosis-affected regions. The underlying hypothesis is the comparison of the risk of brucellosis persistence across all regions of Italy under the same epidemiological and veterinary conditions (here measured by the outbreak duration in the southern affected regions).

In addition, we explored a full range of values of the outbreak duration, from 10 days to 10,000 days, the upper limit used for theoretically assessing the trend of vulnerability to brucellosis for varying outbreak durations.

The per-animal transmission rate 𝜆 is left as a variable to identify the critical conditions for brucellosis persistence in each region, as explained in the following subsection.

Epidemic vulnerability assessment, control strategies, and compliance

We introduced a measure of vulnerability 𝜈 quantifying the risk for brucellosis persistence in a given region, once the disease is introduced in the region. It is defined as the inverse of the critical value 𝜆 ! of the transmissibility 𝜆, 𝜈 = 1 𝜆 ! , where 𝜆 ! quantifies the critical condition for the endemic state of the disease [START_REF] Anderson | Infectious Diseases of Humans: Dynamics and Control[END_REF][START_REF] Keeling | Modeling Infectious Diseases in Humans and Animals[END_REF]. If the transmissibility is larger than the critical value, 𝜆 > 𝜆 ! , the model predicts the disease to spread through the cattle trade system and become persistent; if the transmissibility is lower than this value, 𝜆 < 𝜆 ! , the model predicts the disease to go extinct.

To compute the epidemic vulnerability of each region to bovine brucellosis and how it depends on cattle trade patterns and outbreak conditions, we consider the infection propagator approach explicitly integrating time-resolved animal movements among premises (Valdano et al., 2015a). The approach is based on the SIS spatial transmission model described above and parameterized with the outbreak data. Adopting a Markov chain perspective [START_REF] Wang | Epidemic spreading in real networks: An eigenvalue viewpoint[END_REF][START_REF] Gomez | Discrete-time Markov chain approach to contact-based disease spreading in complex networks[END_REF] under the assumption of locally treelike networks [START_REF] Gleeson | Accuracy of mean-field theory for dynamics on real-world networks[END_REF][START_REF] Radicchi | Beyond the locally treelike approximation for percolation on real networks[END_REF], the equations describing the SIS propagation among farms connected by timeresolved trading links are:

𝑝 !,! = 1 -1 -1 -𝜇 𝑝 !!!,! 1 -𝛬 !!!,!" 𝑝 !!!,! ! (1)
where 𝑝 !,! is the probability that farm 𝑖 is infected at time 𝑡 and 𝛬 !!!,!" is the transmission probability from 𝑗 to 𝑖 at time 𝑡 -1, defined previously. By mapping the process into a multilayer formalism accounting for both spreading and network dynamics (Valdano et al., 2015a), the infection propagator approach allows for the analytical solution of the linearized Markov chain description of the spreading process, with the epidemic threshold 𝜆 ! expressed as the solution of the equation:

𝜌 𝑃(𝜆 ! , 𝜇) = 1 (2)
where 𝜌 is the spectral radius of the following matrix:

𝑃(𝜆, 𝜇) = (1 -𝜇 + 𝛬 ! ) ! . ( 3
)
The generic element 𝑃 !" represents the probability that brucellosis can spread from an infected farm 𝑖 at the beginning of the time period under study to farm 𝑗 at the end of this period through time-respecting transmission paths along the temporal trading links of the network. For this reason it is denoted as infection propagator. More details on the analytical treatment are provided in (Valdano et al., 2015a(Valdano et al., , 2015b)).

For each region, we compute the brucellosis vulnerability 𝜈 = 1 𝜆 ! , with 𝜆 ! obtained from Eq. ( 2) where the infection propagator 𝑃 is parameterized with cattle trade data and brucellosis clearing rate 𝜇 obtained from regional outbreak data. We compute fluctuations of the vulnerability by taking into account the empirically obtained fluctuations of the outbreak duration per farm (Table 2).

The SIS transmission scenario implicitly considers the implementation of control strategies, as the model allows for a farm to clear the infection after an outbreak. Their specific details, such as e.g. the number and timing of testing and culling of infected animals, cannot be explicitly considered here because of the farm-level description of our transmission model. The promptness of their implementation and their efficacy are however effectively integrated and represented by the duration of the outbreak.

In addition, we measured the compliance to animal movements ban by identifying the infected farms that continue to trade animals while infected and characterize their trading behavior with respect to the same seasonal period in a previous year when they were brucellosis free (also accounting for yearly variations of overall trading volume).

Statistical analyses

Spearman correlation coefficients were computed to test the correlation between the regional brucellosis vulnerability and a set of different features: (i) the number of brucellosis outbreaks experienced in the region; (ii) animal trade features, such as the average farm in-degree and average farm in-strength; (iii) average regional cattle market value (2016 data) (RICA, -); (iv) farming practices, considering the number of premises with pastures per region (2010 data, onetailed test, as a decrease in risk induced by pastures is not supported by biological plausibility) (ISTAT, 2011).

In addition, we analyzed the relation between the number of outbreaks experienced by a single farm and the number of herds purchased from infected farms.

Results

A total of 3,910 outbreaks affecting 3,214 premises were recorded in the period under study in the regions of Puglia, Calabria, Campania, Basilicata, Molise, and Sicilia (Figure 1), with the largest fraction occurring in Sicilia (2,666, 68%). Outbreak duration in a farm was heterogeneously distributed (except for Basilicata and Molise experiencing very few outbreaks), with median values ranging from 104 days in Basilicata to 201 days in Molise (Figure 1 and Table 2), and overall average of 157 days.

A widely heterogeneous vulnerability situation was predicted for brucellosis-affected regions in the south of Italy (Figure 2). Sicilia is by large the region with the highest vulnerability to brucellosis ( 𝜈 = 15.9 [4.3; 190.8] ), followed by Campania ( 𝜈 = 8.2 [2.2; 318.0] ). Most importantly, the estimated vulnerability per region was strongly associated with the number of outbreaks recorded in the region (Spearman 𝑟 =0.82, 𝑝 =0.04).

Risk assessment results were highly heterogeneous also for the regions in the center and north of the country, with vulnerability values ranging from 𝜈 = 1.6 in Liguria to 𝜈 = 364.8 in Lombardia, the region with the highest predicted risk in the country. Unexpectedly, we found considerably higher vulnerability estimates in the northern OBF regions compared to the affected regions in the south, once the model was parameterized in those regions with outbreak statistics from the south.

A large difference in trading and farming presence was reported between the north and the rest of the country. Almost half of the total number of premises (90,407, 47%) was located in the northern regions, and the vast majority of animal movements originated in those same regions (2,967,897, 80%, Figure 3). On the other hand, the proportion of animals traded within each region compared to across-region movements was quite stable across the different areas.

The regional vulnerability to brucellosis had a strong association with the average in-degree (𝑟 = 0.85, 𝑝 < 10 !! , panel c of Fig. 3) and the average in-strength of a farm in the region (𝑟 = 0.65, 𝑝 < 10 !! , panel d). The association was moderate with the number of premises with pastures in the region (𝑟 = 0.4, 𝑝 = 0.04, panel b of Fig. 3).

Given that no accurate parameterization is possible for the transmission model in the OBF regions because of the absence of outbreaks, we synthetically explored outbreak durations ranging from 1 to 10 ! days. Vulnerability was found to increase with the average outbreak duration, as expected (Figure 4). Lombardia was at a consistently higher risk (two orders of magnitude) compared to Sicilia. We found that the vulnerability estimated in Sicilia based on the region's brucellosis outbreak duration of 157 days would be recovered in Lombardia if outbreaks lasted on average 12 days.

Regional vulnerability to brucellosis (parameterized on southern outbreaks) was moderately associated with the average regional cattle market value (𝑟 = 0.56, 𝑝 = 0.01, Figure 5), indicating that the most vulnerable regions are also the highest capitalized markets.

Finally, we analyzed the compliance of farmers to the regulatory framework put in place in case of brucellosis outbreak declared in affected premises. Despite the imposed movement ban following the detection of the infection, we found that 15% of the infected premises continued to trade (Figure 6). Approximately half of them traded at least 50% or more of the animals compared to the same period of the year while non-infected, with 17% increasing their trade by 150%. The number of outbreaks occurring in a given farm was strongly associated with the number of traded herds originated from infected premises (𝑟 = 0.88, 𝑝 < 10 !! ).

Discussion

Despite continuous progress in the control of bovine brucellosis in Italy, leading to a decline in prevalence from 0.016 to 0.08 in the period 2009-2016 ("Sistema Informativo Veterinario," n.d.), complete eradication has not been achieved and 21% of provinces in the country are still affected, with a significant economic damage to the agricultural and food industries. Here we introduced a novel mathematical approach to estimate the vulnerability of regional cattle populations to brucellosis persistence, based on the spatial transmission of the disease through animal movements. Parameterized on empirical data from the affected regions, our approach is able to capture the large epidemiological heterogeneity reported in these regions and independently explain the number of brucellosis outbreaks (re-)occurring in the south of Italy. This reveals that the introduced vulnerability is an accurate indicator of the likelihood of disease persistence in a given area, showing the potential of a synthetic assessment for veterinary epidemiology based on animal movements and disease spatial transmission.

Comparing the affected regions with OBF ones through the vulnerability indicator becomes instead problematic as it suffers from an incomplete parameterization. Having eradicated the disease since many years, there is indeed no outbreak data to accurately inform our transmission model and specifically Eq. (3). Our findings showed that, in presence of endemic circulation of brucellosis in the whole country with infection clearing rates in the farms similar to what recorded in the south, regions of the north would be considerably more vulnerable than those in the south. Several factors drive this result. Distribution of farms is denser in the north, an area of the country that is highly industrialized and characterized by intensive farming and production.

Even though the proportion of animals moved within the region is similar throughout the country, trading is more frequent in the north where premises exchange animals with a larger number of holdings and in larger batches compared to center and south. The number of connections and the total volume of traffic going through a node are well-established drivers for infection spread in a host population [START_REF] Anderson | Infectious Diseases of Humans: Dynamics and Control[END_REF][START_REF] Pastor-Satorras | Epidemic spreading in scale-free networks[END_REF][START_REF] Lloyd | Epidemiology. How viruses spread among computers and people[END_REF][START_REF] Moreno | Epidemic outbreaks in complex heterogeneous networks[END_REF][START_REF] Keeling | Modeling Infectious Diseases in Humans and Animals[END_REF][START_REF] Barrat | Dynamical processes on complex networks[END_REF][START_REF] Dubé | A review of network analysis terminology and its application to foot-and-mouth disease modelling and policy development[END_REF][START_REF] Martínez-López | Social network analysis. Review of general concepts and use in preventive veterinary medicine[END_REF][START_REF] Vernon | Representing the UK's cattle herd as static and dynamic networks[END_REF]. Farms that are on average better connected also increase their possibility to contract the infection from neighboring farms, and, on their turn, they can transmit the disease to a larger portion of the trading system, strongly increasing its vulnerability. In addition, northern regions did not suffer from travel bans reducing commercial trade in the studied period because of their OBF status, compared to southern regions. These results clearly show the role of animal movements in contributing significantly to the maintenance of the disease, confirming previous results obtained in Spain identifying the number of purchased animals as a risk factor for brucellosis persistence [START_REF] Cowie | Shared risk factors for multiple livestock diseases: a case study of bovine tuberculosis and brucellosis[END_REF][START_REF] Dias | Epidemiological situation of bovine brucellosis in the State of Paraná, Brazil[END_REF].

Other types of animal movements beyond trade may play an important role in the disease diffusion, such as movements to pastures [START_REF] Dias | Epidemiological situation of bovine brucellosis in the State of Paraná, Brazil[END_REF][START_REF] Abernethy | Epidemiology and management of a bovine brucellosis cluster in Northern Ireland[END_REF][START_REF] Calistri | Risk factors for the persistence of bovine brucellosis in Sicily from 2008 to 2010[END_REF][START_REF] Cowie | Shared risk factors for multiple livestock diseases: a case study of bovine tuberculosis and brucellosis[END_REF]. These movements are not included in the cattle trade database used in this study as Italian regulations do not require their compulsory tracking. Using a different dataset, we were able however to find a moderate association of the brucellosis vulnerability of each region with the number of premises with pastures. Direct contact between cattle at pasture was found to be the most likely driver for bovine brucellosis transmission in Northern Ireland [START_REF] Abernethy | Epidemiology and management of a bovine brucellosis cluster in Northern Ireland[END_REF], where several neighboring herds reported epidemics breaking out during summer (when they more likely moved to pastures), and epidemiological investigations identified deficiency boundary fencing in the area. Similar results were obtained also in Spain, where the number of farmers sharing summer pastures was identified as a significant risk factor for brucellosis [START_REF] Dias | Epidemiological situation of bovine brucellosis in the State of Paraná, Brazil[END_REF][START_REF] Cowie | Shared risk factors for multiple livestock diseases: a case study of bovine tuberculosis and brucellosis[END_REF]. In the Italian region of Sicilia, a previous study indirectly concluded that the habit of moving animals to shared pastures may underlie the observed clustering of infected herds in specific locations, without however providing a statistical analysis for lack of data (Calistri 2013). Here we show that the possible risk provided by the specific type of husbandry adopted involving the use of pastures is aligned with the vulnerability computed on commercial trade, thus strengthening our overall risk assessment. The region with the largest number of premises with access to pastures is indeed Sicilia with more than 31,000 premises (ISTAT, 2011), followed by regions in the north such as Piemonte and Veneto also having indeed a high vulnerability. Though eradicating a disease in islands like Sicilia is expected to be eased by the possibility of better isolating the territory and defend it from external importation, these areas are also the ones characterized by a breakdown of the use of the agricultural territory that facilitates uncontrolled contact between neighboring herds: for example, more than 40% of the farming territory is used for pastures in Sicilia, compared to only 18% in the center regions (ISTAT, 2016).

These findings analyzed the vulnerability of Italian regions under the same epidemiological and control conditions throughout the country, i.e. a hypothetical and non-realistic scenario for OBF regions. The synthetic exploration of the average brucellosis outbreak duration in a farm however showed that Lombardia, the highest vulnerability northern OBF region, would experience a risk similar to Sicilia for infections lasting for about one tenth of the average duration in a Sicilian farm, i.e. approximately 10 days. Given that brucellosis has been eradicated in Lombardia since many years, these findings seem to point to a considerably prompter and more efficient control in the regions of the north and center than those in the south, thus minimizing the duration of an outbreak following an importation and effectively preventing its further spread. Since farmers are required to declare all clinical signs associated to brucellosis according to national regulations, the duration of the outbreak considered in this study is not only a measure of disease progression in time in the affected herd, but also quantifies the response of the farmer and of veterinary services called for its control, having an inevitable impact on brucellosis persistence. In Sicilia, Calistri et al. found that the time between detection of the infection and slaughtering of infected animals influences the health status of the herd in the following testing [START_REF] Calistri | Risk factors for the persistence of bovine brucellosis in Sicily from 2008 to 2010[END_REF].

Measuring promptness and efficacy of interventions directly, for instance through a survey, might provide additional evidence to further support our findings. Very few studies have however considered in detail the possible variety of biosecurity practices adopted on premises to reduce transmission between farms through direct contacts (e.g. investigations or testing prior to animal purchases), indirect contacts (e.g. reducing possible contamination of equipment, personnel, vehicles), or transmission within farms (e.g. enhanced cleaning, hygiene, change of material, etc.). This is mainly due to the large costs and efforts required to conduct biosecurity surveys to gather information on preventive actions at the premises level and to farmers' acceptability. Few published data exist for the UK [START_REF] Davison | Dairy farm characteristics, including biosecurity, obtained during a cohort study in England and Wales[END_REF][START_REF] Brennan | Biosecurity on Cattle Farms: A Study in North-West England[END_REF], the US [START_REF] Brandt | Biocontainment, biosecurity, and security practices in beef feedyards[END_REF][START_REF] Hoe | Opinions and Practices of Wisconsin Dairy Producers About Biosecurity and Animal Well-Being[END_REF], and Sweden [START_REF] Nöremark | Application of routines that contribute to on-farm biosecurity as reported by Swedish livestock farmers[END_REF].

Little is available for cattle farms in Italy and is generally focused on specific events or activities [START_REF] Fratini | Raw milk for sale in Pisa province: biosecurity of dairy farms and hygienic evaluation of milk[END_REF], or on affected regions [START_REF] Graziani | La brucellosi in Italia dal[END_REF] and thus not generalizable. To overcome the lack of biosecurity data, we thus tested the correlation between vulnerability and regional market value of the cattle compartment, finding a moderate association. This indirectly suggests that premises at a considerably higher risk because of their intensive farming practices are also the ones that implement stricter, prompter and more efficient preventive and control policies to protect the large capital invested in their production. Circulation of brucellosis on northern premises would cause dramatically larger economic losses compared to extensive farming in the south.

Efficacy of interventions is also related to the compliance of farmers to regulations. This is generally outlined in official reports monitoring the progress of control activities [START_REF] Graziani | La brucellosi in Italia dal[END_REF], through for example measures of the percentage of effectively tested herds on the total subject to control, or of the percentage of infected animals that are slaughtered. An important part of brucellosis control is the ban on movements as soon as an infection is detected in a given holding. By crossing the database of animal movements (NDB) and the database of brucellosis surveillance and eradication activities (SANAN) ("Sistema Informativo Veterinario," n.d.), our study allowed for the first time the assessment of farmers' compliance to restrictions on trade while experiencing an ongoing outbreak. Approximately 15% of farmers with infected herds continued to trade despite the policy in place, and half of them moved about the same number of animals or more than they were used to move in the same seasonal period. Most importantly, the number of outbreaks occurring in a given premises is clearly associated with the number of incoming traded herds received from infected premises. Such risk was previously assessed only in Northern Ireland, where it was found to be 19 times higher compared with animals from herds with no history of infection [START_REF] Abernethy | Epidemiology and management of a bovine brucellosis cluster in Northern Ireland[END_REF]. Our study confirms that movements are therefore significant for disease dissemination and persistence. This was not previously observed in the analysis of brucellosis risk factors in Sicilia [START_REF] Calistri | Risk factors for the persistence of bovine brucellosis in Sicily from 2008 to 2010[END_REF], likely because of confounding factors such as the large number of pastures present in the sole region under study.

The strong reluctance of producers in complying with eradication programs is expected to be related to the large losses incurred. The total cost for brucellosis eradication in the region of Lazio in central Italy from 2007 to 2011 was estimated to be 6M Euros with 6.5% contribution of the European Union [START_REF] Caminiti | Tuberculosis, Brucellosis and Leucosis in Cattle: A Cost Description of Eradication Programmes in the Region of Lazio, Italy[END_REF], for an average number of 236,262 cattle heads. While including culling, representing 0.5% of the overall figure, this estimate did not however consider costs associated with movement bans or additional losses for farmers such as decreased milk and meat production. It is important to note that gaining OBF certification halved the overall cost, thus showing the importance of attaining disease eradication through a collective and proactive approach, for both national authorities and individual producers. In addition to measures to improve compliance, different management strategies can be envisioned, some of them already adopted by other countries, such as e.g. testing prior to movements, quarantine of animals following trade, or cattle restrictions on larger areas, i.e. extending travel bans from the farm level to the province or regional area. This is especially important for diseases characterized by a silent spreading phase with a latent sub-clinical infection that may hide epidemiological links between premises due to the long interval between infection and disclosure.

Finally, we stress the importance of cross-matching different databases such as the one for bovine identification that tracks animal movements and the database for the continuous monitoring of surveillance and control activities, in order to uncover unexpected behaviors weakening the progress of efficient brucellosis eradication, as we showed here. We suggest that such cross-matching is performed routinely by veterinary authorities to considerably enrich the knowledge on the health status of animal populations and improve the accuracy of the evaluation of veterinary policies for updates and replanning.

This study is affected by some limitations. First, we did not consider interactions between cattle and wildlife that may act as a reservoir for Brucella pathogens. Spillovers from wildlife are known to pose a greater risk for domestic pigs than for cattle, due to the presence of hares and wild boars infected with Brucella suis [START_REF] Godfroid | Brucellosis in the European Union and Norway at the turn of the twenty-first century[END_REF]. In Spain, wild ruminants were not identified as a significant brucellosis reservoir for livestock [START_REF] Munoz | Spatial distribution and risk factors of Brucellosis in Iberian wild ungulates[END_REF]. Contacts with wildlife also strongly depend on farming practices. Indoor farming is the most common breeding practice adopted in Italy with the effect of strongly limiting brucellosis transmission through interactions with wildlife.

Second, our assessment of the vulnerability of cattle population to brucellosis refers to the risk of persistence within the country, once the disease has already been introduced. Thus, it does not account for the probability of importation that may vary throughout the country. The peculiar geographical configuration and position of Italy may indeed increase the exposure of southern regions to exotic pathogens from high-risk areas, such as Northern Africa, Greece, and others. A recent phylogenetic study found indeed that bovine brucellosis isolates from Italy are substantially different than those recovered in northern regions of Europe, and are more closely related to those found in the Middle East [START_REF] Garofolo | Origins and global context of Brucella abortus in Italy[END_REF]. In this study we decided to focus on within-country transmission because of lack of accurate estimates for the risk of introduction of brucellosis from out of the country.

Conclusion

Bovine brucellosis remains a serious problem in the southern regions of Italy, notwithstanding the long-term and intensive eradication efforts, and causes important economic consequences on the Italian cattle production system, the 2nd largest market in the EU by trade volume. Here we introduced a novel modeling approach assessing the vulnerability of Italian regions to brucellosis persistence, based on empirical movement data and parameterized on outbreak data at farm level. Our findings showed the accuracy of the vulnerability indicator in predicting the number of outbreaks experienced in the affected regions. Most importantly, they identified for the first time animal trade movements as a significant driver for the maintenance of the disease in this area, with an additional appreciable contribution of the use of pastures favoring contiguous spread between neighboring herds. By comparing OBF regions with affected ones, our analysis uncovered the role of limited compliance to trade bans in the southern regions and biosafety measures protecting high production values in the northern regions in explaining the extremely diverse epidemiological situation reported in the country. Providing a synthetic vulnerability indicator, our approach offers a novel tool for veterinary epidemiology based on animal movements and disease spatial transmission that can be readily applied to other epidemiological contexts. Figure 5. Impact of cattle market value on regional vulnerability to brucellosis. Relation between vulnerability and average cattle market value per region. Each dot represents a region and is color-coded according to its geographic position (north, center, south, as in Figure 3). The black straight line is a linear fit shown as a guide to the eye.

Tables

FiguresFigure 1 .

 1 Figures

Figure 2 .

 2 Figure 2. Vulnerability of Italian regions to bovine brucellosis and comparison with number of outbreaks. a) Map of predicted vulnerability per region. The color scale refers to the estimated value of 𝜈 per region, when the model is parameterized with the data of Table 2. b) Relation between vulnerability and number of outbreaks per region in the south. Whisker boxes (red line at the median, box at 50% confidence interval, whiskers at 95% confidence intervals) represent the variation in the predicted vulnerability due to fluctuations in the estimated outbreak duration from data. The red straight line is a log-log fit shown as a guide to the eye.

Figure 3 .

 3 Figure 3. Impact of trading and farming practices on regional vulnerability to brucellosis. a) Distribution across the country (north, center, and south) of: number of premises, number of bovines moved out of a farm, proportion of animals traded within the area. b), c), d) Relation between vulnerability and: number of premises with pastures (panel b), average in-degree (panel c), average in-strength (panel d) per region. Each dot represents a region and is colorcoded according to its geographic position (north, center, south, as in plots of panel a). Black straight lines are linear fits shown as guides to the eye.

Figure 4 .

 4 Figure 4. Impact of outbreak duration on regional vulnerability to brucellosis. Relation between vulnerability and outbreak duration for Sicilia (non-OBF region at highest predicted risk) and Lombardia (OBF region at highest predicted risk). Median duration of brucellosis outbreak in the south (vertical grey line) is shown together with its 95% confidence interval (vertical grey area).

Figure 6 .

 6 Figure 6. Compliance to trade bans and impact on bovine brucellosis diffusion. a) Number of infected premises according to their trading behavior while infected. b) Cattle movement volume variation for infected premises that trade when infected. c) Relation between number of outbreaks experienced by farms in a given province and number of movements received from infected premises. The black straight line is a linear fit shown as a guide to the eye.

Table 1 . Basic description of regional cattle trade systems in Italy.

 1

		Region	#premises	#trading links	#moved bovines	in-degree	in-strength
				total	avg/y	total	avg/y	avg/y	avg/y
		Piemonte	18,993	598,155	85,450	1,669,615	238,516	3.99	16.87
		Valle d'Aosta	1,632	48,876	6,982	103,144	14,735	3.20	9.10
		Lombardia	22,891	759,936	108,562 2,929,995	418,571	3.35	23.44
	NORTH	Trento Alto-Adige Veneto	11,637 19,492	400,109 506,377	57,158 72,339	608,486 2,173,769	86,927 310,538	2.31 2.32	4.25 17.44
		Friuli Venezia Giulia 3,133	108,662	15,523	221,740	31,677	1.58	6.40
		Liguria	1,834	13,359	1,908	28,091	4,013	1.03	2.18
		Emilia Romagna	10,795	532,423	76,060	1,622,371	231,767	2.10	16.16
		Toscana	6,075	51,586	7,369	146,927	20,990	1.39	4.68
		Umbria	4,862	37,460	5,351	98,684	14,098	1.26	3.94
	CENTER	Marche Lazio	5,995 15,098	49,346 124,222	7,049 17,746	123,476 354,362	17,639 50,623	1.30 1.30	4.00 4.47
		Abruzzo	7,021	52,625	7,518	107,585	15,369	1.39	3.36
		Sardegna	10,642	66,542	9,506	410,764	58,681	1.19	8.02
		Molise	3,821	29,528	4,218	55,093	7,870	1.18	2.46
		Campania	14,992	92,117	13,160	214,501	30,643	1.32	3.56
	SOUTH	Puglia Basilicata	5,533 3,729	58,335 27,697	8,334 3,957	191,759 106,833	27,394 15,262	1.39 1.10	6.83 4.38
		Calabria	9,370	36,545	5,221	128,280	18,326	1.13	4.52
		Sicilia	13,051	99,693	142,412 480,367	68,624	1.60	9.10

Table 2 . Outbreaks and their duration per region (median and 95% confidence interval).

 2 assumed value obtained as average of non-OBF outbreak durations

	Region	# outbreaks	Outbreak duration (days)
	Sicilia	2666	155 [68; 1125]
	Campania	533	171 [67; 1007]
	Calabria	478	154 [81; 928]
	Puglia	224	157 [66; 1039]
	Molise	6	201 [94; 212]
	Basilicata	3	104
	OBF regions	0	157*

*

Funding

This study was partially supported by the EC-ANIHWA Contract No. ANR-13-ANWA-0007-03 (LIVEepi).


Dacia Dressen-Hammouda

Adapting methods for teaching work-based literacies to a changing workplace context: Using protocol-assisted modeling

Introduction 1.1 Context for the study

The field of technical writing has undergone significant changes over the last fifteen years. No longer is it sufficient to have "good writing skills" and produce clear manuals. Changing business practices have profoundly transformed what traditionally were writing tasks into the full-scale management of a company's "information meta-products". Writing professionals must now design information by skillfully combining several semiotic resources for each audience, situation and context, including textual, visual, spatial, audio, video, and code. One question teachers can legitimately ask in this context is, how can university programs in professional writing best help prepare students for such complex work-based literacies?

While teaching particular professional genres (e.g., a set of instructions, a user manual) can be one way to start, it is highly unlikely that such knowledge alone will help students learn to function successfully as professionals in such a complex, dynamic and multi-semiotic context. This observation is made even more salient when we consider that since [START_REF] Ivanič | Writing and Identity: The Discoursal Construction of Identity in Academic Writing[END_REF] we know that mastering contextual discourses and genres is as much, if not more, a matter of taking on new -and often competing -identities as it is of knowing how to wield the relevant surface features of the genres students will need to produce as professionals. For this reason, students typically have a hard time taking on an authentic voice and professional identity in their productions, an entirely expected problem since they are not yet legitimate members of the workplace community they are aiming to participate in (Lave & Wenger 1992).

The problems engendered by taking on new identities have been central in writing research since [START_REF] Ivanič | Writing and Identity: The Discoursal Construction of Identity in Academic Writing[END_REF]. In effect, the difficulties involved in taking on the identity of a target community can impede a writer's legitimate participation in that community (see also Lea & Street 1999, Lillis 2002, Street 1995[START_REF] Schriver | Dynamics in Document Design: Creating Text for Readers[END_REF]. Today, much work still remains to be done on exploring the implications of identity for teaching professional and academic writing. In technical writing, for example, developing a relevant professional identity requires simultaneously fostering relevant attitudes and behaviors as well as skills in technical and professional writing, information design, visual design, user studies methods, project management, scientific research methods, web/mobile application design, tutorials and online help design, and communication strategies. This topic is also an important area of research for international networks of writing researchers, especially in terms of intercultural communication. In effect, students in professional and academic writing programs in Europe are most often required to navigate the conditions of learning to write not only in their first language, but often in one or several additional languages, as well. What this has to say about switching between the salient and implicit norms from one language to the next is very relevant to issues of identity in writing, as it adds to the complexity of the task. Students learning the indexicalities of professional writing in the context of technical communication and information design must also attend to the ways in which those indexicalities differ across cultures. In addition to writing, they must learn to pay attention to the indexes of community belonging -attitudes, behaviors, implicit mental representations -including navigating how these indexicalities are expressed differently in different cultures. This is certainly the case for professionals who were former students in our program. Today they must juggle managing technical communication projects across both languages and cultures, in French, English, and one or several additional languages (German, Italian, Spanish, Portuguese, Russian, Arabic, or Chinese). Given the complex pedagogical needs of such students, it may perhaps be somewhat unexpected that the primary claim to be made in this paper is that stimulating awareness and consideration of audience, long a priority in writing research and pedagogy, is still essential. In effect, to be effective, writers need to have "an image of the intended audience interacting with the text" (Schriver 1989, p. 4). This paper describes results from an ongoing study mapping the emergence of situated work-based literacy in French and Dutch technical writing students, using a method specifically designed to elicit more well-developed representations of the actual readers and users of their work. It uses a modified version of [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF] protocol-assisted modeling (PAM) approach, designed to help writers construct a more accurate mental model of how readers think and react to information. Fifteen students enrolled in a master's program in technical communication participated in a semester-long study in which they were asked to predict potential problems for readers in six poorly designed documents, then revise their evaluation based on a think-aloud protocol transcript showing how the document's actual users reacted to it. A post-test assessed changes in their ability to anticipate reader problems. Writing pedagogies such as these may better contribute to the long-term construction of students' professional identities. In addition, the approach could very well be a relevant addition to writing pedagogies by researchers in discourse studies, applied linguistics or English Language Teaching, in that it specifically helps students learn how to better target the specific audiences they are writing for, including audiences whose native language and culture are not those of the author.

2. Background: What is protocol-assisted modeling?

Protocol-aided revision

In the early 1980s, [START_REF] Swaney | Editing for comprehension: Improving the process through reading protocols[END_REF][START_REF] Hayes | Uncovering cognitive processes in writing: An introduction to protocol analysis[END_REF]) developed a technique for helping writers to revise texts based on a method they adopted from industrial performance testing: think-aloud protocols (also described at length by Carroll 1997). In this method, participants were asked to perform a task while thinking aloud as they interacted with a document and/or machine. Because they were asked to verbalize anything that came to mind while they were carrying out the requested task(s), their comments revealed the key difficulties they encountered while using the document, both in terms of problem type and placement.

The resulting technique adapted by [START_REF] Swaney | Editing for comprehension: Improving the process through reading protocols[END_REF][START_REF] Hayes | Uncovering cognitive processes in writing: An introduction to protocol analysis[END_REF], called "protocol-aided revision", provided think-aloud protocols to writers to help them revise their texts: "Evaluators make visual and/or audio recordings of readers as they think aloud while comprehending a text. The transcripts are then analyzed for evidence of readers' problemsolving strategies, comprehension, misuse and error recovery, access and retrieval behaviors, inferences and predictions, level of satisfaction and preferences. This information was then used to guide the revision of: insurance forms, apartment leases, computer manuals, or medical support forms." (Schriver 1989, p. 28) 2.2 Reader protocol teaching method [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF][START_REF] Schriver | Dynamics in Document Design: Creating Text for Readers[END_REF] adapted the protocol-aided revision approach to teach writing to university students, with the idea being that the approach would help writers develop a stronger image of readers. In a series of papers [START_REF] Schriver | Evaluating text quality: The continuum from text-focused to reader-focused methods[END_REF](Schriver , 1990[START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF], she reviews a number of readercentered techniques that are typically used to help teach writers how to create "an image of the intended audience interacting with the text" (Schriver 1990, p. 4). Among them, she cites audienceanalysis heuristics, peer review, and role-playing, which she found to be less successful than another technique, "protocol-assisted modeling" (PAM, also known as the "reader protocol method", Schriver 1992, and "protocol-aided audience modeling " Schriver 1997, p. 475). In an experimental study [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF], she compared the effectiveness of traditional audience awareness methods and PAM, and found that students who were exposed to the PAM method were: "better able to diagnose problems from the readers' point of view; more sensitive to problems caused by omissions or information gaps; more aware of problems at the global level of text." (1992, p. 202) The PAM method was shown to improve her student writers' ability to anticipate readers' needs. She suggested that the method could be used as a helpful supplement to other methods for teaching the process of 'imagining the reader.' As she also argued, the method shows significant potential for teaching tacit and perceptual knowledge because no explicit instruction is given to students on how they are to evaluate the texts and anticipate reader problems. In other words, by analyzing samples of reader responses to various texts, students gradually create their own 'intuitive', but empirically grounded, understandings and mental representations about real reader information needs. This is important because Previous research and classroom experience tell us that examples can be powerful ways of teaching perceptual knowledge, that is, the "seeing" or "listening" abilities that allow people to recognize significant categories of objects or events in their environment (Bransford, 1979;Brown & Campione, 1981;Sweller & Cooper, 1985;VanLehn, 1986;Zhu & Simon, 1987). Perceptual knowledge is important for instigating or guiding action in a variety of contexts for learning and doing. […] In particular, I explored the hypothesis that extensive experience in interpreting readers' feedback (provided through transcripts of think-aloud reading protocols) would help writers to become more aware of how readers construct text. (Schriver 1992, p. 182)

A description of protocol-assisted modeling

In this teaching method, in which students are taught over ten lessons to better anticipate reader reactions, [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF][START_REF] Schriver | Dynamics in Document Design: Creating Text for Readers[END_REF] proposes a four-part approach:

(1) present students with a problematic document (i.e., a poorly written and poorly visualized document that will cause comprehension problems). Students are asked to read the text and identify problems for the reader;

(2) give students a guided writing task in which they describe the features of the text they think will pose problems for the reader;

(3) have students read a think-aloud protocol transcript of a user attempting to understand and use the document;

(4) give students a second guided writing task in which they describe any other problematic features they may have missed when first evaluating the document. A sample PAM from Schriver (1997, p. 477-478) is provided (Figures 1234). Figure 1 shows an excerpt taken from a problematic instructions text, while Figure 2 shows the writing prompts students received after reading the original text.

EMACS: Commands for creating text

EMACS enables you to manipulate words, sentences or paragraphs of text. In addition, there are commands to fill text, and convert case.

Editing files of text in a human language ought to be done using Text mode rather than Fundamental mode. After describing the document features they predicted would be problematic for readers, students then read the think-aloud protocol transcript of an actual user trying to navigate that same document (Figure 3). As the final task in the exercise, students are once again asked to respond to a set of written prompts (Figure 4), intended to help them identify any other problems in the original document after having read about how a particular user reacted upon reading the document. Despite their potential, using think-aloud protocols to create teaching materials for developing audience awareness does pose a number of problems, as described by Schriver (1989, p. 27):

-Think-aloud protocol transcripts inevitably have "gaps" when participants forget to speak. In effect, one of the challenges involved in using think-aloud protocols is keeping the participants talking throughout their entire interaction with the document and/or machine. Quite often, people

Writing task (1):

1. Read the draft document.

2. Predict the reader's problems with this document.

3. Write your answers below. Editing files of text in a human language human language? Boy that sounds strange, what could they be distinguishing here? Maybe computer language or machine language from human language? ought to be done using text mode rather than fundamental mode. Writing task (2):

Ok, now I'm going to try …

1. Now, read the think-aloud protocol transcript.

2. Use the reader's comments to identify additional problems in the draft.

3. Write your answers below.

forget to speak as they become engaged with the task at hand, causing the transcript to give an incomplete account of the problems they encountered. The final transcript might therefore fail to fully account for all the problems a particular user may have had, although it can still give students a very good idea of many of the problems actually encountered.

-The second point follows from the first: participants may make "mental leaps" and reach a conclusion without verbalizing the intermediate steps of how they reached their understanding, once again leading to potentially incomplete information in the protocol transcript.

-If the original document contains visuals or other nonverbal representations, participants may be unable to verbalize what they are thinking.

-Protocols are time-consuming to make.

This final point is of particular concern when deciding whether or not to integrate the method into a professional or academic writing class. In effect, a significant amount of time needs to be set aside for creating the teaching corpus, including finding suitable examples of documents. Ideally, documents chosen should show clear enough problems from a pedagogical point of view while, at the same time, not being overloaded with problematic features. Clear criteria on whether or not to include the documents in the teaching module need to be decided at the outset, so as to avoid going through the inconvenience of spending a considerable amount of time both recording a live participant user-testing the document and transcribing the session, only to conclude in the end that the document is pedagogically unsuitable. In addition, issues of pedagogical progression -in other words, deciding whether it would be interesting to have students analyze one document before another, and why -should also be addressed before running the module in a classroom setting.

Another drawback concerns whether or not, due to study size, it is feasible to evaluate the method's effectiveness in comparison to the other methods commonly used to develop audience awareness (audience-analysis heuristics, peer review, or role-playing). In [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF] rigorously constructed experimental study, the studied population included 117 students enrolled in ten professional writing classes. The population size made it feasible to compare methods, using five classes as an experimental group, and five as control. Depending on teaching conditions, replicating Schriver's study could prove unethical if participants are constrained to a single class, and are taught variously using either PAM or traditional audience awareness methods. Such would have been the case in the current study, which describes the implementation and results of using PAM in a single group of 15 students. As a consequence, this study takes Schriver's claims about the effectiveness of PAM as its starting point, in order to focus on how it might contribute to the development of the students' professional identity and workplace literacies.

The purpose of the study was to examine the implementation of the PAM method with a small group of Master's students in technical communication and information design. The results from the study are very much to be taken as preliminary within a larger study underway looking at how professional writing programs can better help students learn the indexicalities of professional writing, specifically in the context of technical documentation and information design in France. In the conclusion, the method is evaluated, looking specifically at whether it effectively prepares students for the complex workplace contexts they will encounter, in which their ability to frequently and rapidly adapt to user and contextual information needs is crucial.

Methods

Research questions

A corpus of texts was designed for a 15-hour, first-year Master's course on information design, where the topics ranged from a focus on message design and Plain Language principles, to design theories and graphic design principles, visual design (color, shape and typography) and information visualization. The PAM exercises were created specifically to reflect these aspects of the course.

All students had previously been introduced to traditional audience analysis techniques (using guidelines, peer review and audience analysis) in a technical communication course taught the previous semester. At the end of the course, they produced and user-tested a user guide. During the user tests, students were also initiated into carrying out and transcribing think-aloud protocol analysis, and so had been familiarized with the technique.

The current study was designed to answer the following two questions:

(1) Does the PAM teaching method impact how well students identify problems in a document?

(2) If yes, how so?

Participants

Fifteen first-year Master's students participated in the study. Of those fifteen, only nine participants were targeted for analysis because they provided a full set (for various reasons, the remaining six participants were unable to complete the entire set of PAM exercises). Of those nine participants, seven were native speakers of French, and two of Dutch. Five were male, and four were female. Schriver (1997, p. 477-78) was used as a model to create a corpus of eight PAM exercises. The corpus included Schriver's sample, plus seven further exercises, each of which consisted of the fourpart approach shown in Figures 1234. Of those, two exercises were eliminated retrospectively from the analysis due to faults in their design. The other five PAM exercises used the following original documents: (1) the online explanation originally provided by Amazon when it introduced its currency converter;

Materials

(2) an administrative university document providing instructions for setting up hiring committees;

(3) a set of instructions including both text and images on how to install a wall clock; (4) an online user guide for using plagiarism detection software; and (5) an educational brochure intended to help adolescents safely manage their interactions with the police. Two of the documents were in French (1 & 2), the remaining four were in English (3-5, plus the sample PAM shown in Figures 1234).

Procedure

Participants carried out a PAM exercise each week. Alternately, one was carried out in class, and the other was completed independently outside of class. Each PAM exercise was made available on the course Moodle, and participants were asked to upload their completed PAMs onto the course Moodle. All participants responded to the writing prompts solely in English.

Results

Comparing the results obtained in the current study to the original claim, we can recall that [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF] found that students who had been exposed to the PAM method had a greater ability to:

identify and propose solutions to the global aspects of text quality (i.e., in terms of rhetoric, organization, logic, cohesion, and tone);

predict readers' needs.

Progressive increase in the length of written responses

One of the first observations to be made in the current study is that the participants' analysis of the documents became more detailed over time. This observation is reflected first and foremost in the number of words, as seen in Figure 5. While at the outset, both the first and second written responses averaged the same length (i.e., about 40 words), as time went on, participants proposed more observations based on their own analysis of the documents, than they did after reading the think-aloud protocol transcript.

Early focus on surface features

Interestingly, not only did the written responses increase quantitatively, they also demonstrated a qualitative shift in focus. The earliest written responses showed a greater tendency to focus on surface-level features, such as word choice (e.g., specialist jargon) and inappropriate grammar (i.e., non-compliant with Plain Language principles). In the first PAM exercise, for example, participants used a "checklist" approach in their evaluation, attempting to match the principles they had previously studied with the problems they identified in the document:

"Complicated wording and syntax. References to items not present. Vocabulary."

"Problems with specific vocabulary (domain specific, no definitions…). Problems with wordiness: useless words."

"Problem with document: difficult to understand, technical language." "Sentence complexity."

Over the course of repeating the exercises, however, they increasingly moved toward a more reader-centered approach, making more predictions about the problems readers would have based on the documents' actual features, rather than a checklist. In turn, the evaluations they made in the first guided writing responses became comparatively longer than the second guided responses. They also appeared to integrate the 'before' and 'after' analyses from the previous exercises, and to use that to formulate their own, more detailed observations, with progressively less and less recourse to the think-aloud protocol transcripts to identify the problems.

Increasing focus on predicting reader reactions

For example, over time, participants steadily focused more on predicting actual reader reactions based on the problems they themselves had identified in the documents. They indicated how the actual document features might impede reader interaction, as seen in comments such as:

"A user that is skimming the document will have a hard time finding the chapter titles. Too many red arrows and red lines in the images make it difficult to discern what is important. The use of arrows is not linked to the text, making it difficult to establish connections between the text and the images. Sometimes the image is on the left of the page and sometimes on the right which makes it difficult to establish a structure." "Readers will face problems with document usefulness. The content is neither appropriate nor structured. Multiple negatives will cause confusion. Text complexity and the way it's written do not take into account the user's needs. The content focuses entirely on liability, and the reader will be naturally unmotivated. Amazon encourages this lack of motivation with obscure language. Users will quickly forget the content (lack of accessibility)." 4.4 Increased proposals for revision (unprompted)

In addition, all participants gradually offered more diagnostic analyses of the documents, as well as solutions for revision. On both first and second response sheets, they increasingly commented on what, in their opinion, the document authors should have done differently. Such evaluative comments are particularly noteworthy because they were entirely unprompted by the research design (i.e., participants offered them freely, without being explicitly asked to do so by the guided writing tasks): "The guide is not effective: it contains the right information but not in the right order, it should be reorganized (like a forum, with QA format)."

"This paragraph should be situated at the end of the brochure because when people are looking at this they can think that the following information is not important and they won't read it." "Too much text will make the reader skim and miss important information. Warnings at the beginning risk being overlooked. Readers will only read relevant info (7. Operation); they may miss important information. Make an index and use short sentences, make steps. Put warnings in places where absolutely needed. Start the document with the instructions and add other information later." "The background is too stimulating, and risks tiring the reader before he even starts. The yellow box on the right has information in it. It's a menu I think and the tags… I don't know what it is supposed to mean. The fact there is a similar box on the right means that the reader does not know where to start scanning for useful information. Use a calm background. Restructure the entire page. Put the menu in a clearly identified position. Use only 1 box. Maybe put a long horizontal block at the top with menus like on a website. Remove unnecessary and unhelpful information and images."

Discussion and conclusion

Shortcomings of the study

One of the shortcomings in carrying out this study stems from the difficulties encountered in constituting the corpus. In addition to being time-consuming, questions were raised retrospectively about the pedagogical appropriateness of the exercise progression. Whether the order in which the exercises are presented make a difference in terms of how well participants perceive the imagined needs of a document's readers will need to be validated in a later study.

Relatedly, results from the two final exercises (from the original eight) were discarded during the analysis phase, as it became apparent that they were inappropriately placed in terms of pedagogical progression: the problems in the original documents were far too numerous and blatantly obvious to maintain credibility in the eyes of the students, who after completing several PAM exercises were showing substantial sophistication and thoroughness in their evaluations.

How the PAM method contributes to building an effective professional identity

The PAM method is an inductive method, meaning that it does not explicitly point out to students what aspects of the information are relevant to pinpointing difficulties readers may have with a document. In this sense, it allows them to develop -on their own -an 'intuitive' sense of the strengths and shortcomings of professional documents: their perceptual knowledge [START_REF] Schriver | Teaching writers to anticipate readers' needs: A classroom-evaluated pedagogy[END_REF].

Through its ability to develop students' mental representations of a document's readers, the PAM method helps them better adapt their attitudes, behaviors and abilities to a company's needs. There is indirect evidence that the method has already been successful in helping the students who participated in the study to develop a more appropriate professional identity. One line of evidence comes from the positive evaluation of the students' performance by their internship tutors over the course of a mandatory 12-to-16 week company internship. In addition, of the nine students who participated in the study, six have received work-study contracts for their second year as a direct result of the quality of their work during their internships. In France, a work-study contract is the much coveted contrat d'alternance, which allows students to work as salaried employees in a company throughout the second year of their Master's program (spending three days in class, two days in company training); the company covers tuition fees, as well as travel and housing expenses while on site.

The next step in the study will be to build on these initial findings by carrying out a qualitative exploration of the impact of the PAM method, tracking the six students over the course of the coming year during their work-study contracts. To further explore how the PAM method influences students' ability to rapidly adapt their projects to widely variable user/shareholder information needs, the following methods are planned as part of an ongoing project:

semi-structured interviews with the six students, their company tutors and colleagues; onsite observations of their work practices and interactions in the workplace; reflective journals on their changing abilities to design effective information, the difficulties they encounter when doing so, and the strategies they put into play in order to resolve them.

Study implications

Although relatively little attention was paid in the writing research community to Protocol-Assisted Modeling when it was first proposed, it is clearly time to re-assess its potential as a major contributor to professional and academic writing programs, especially in terms of fostering new identities and complex workplace literacies. The implications of using Protocol-Assisted Modeling are far-reaching:

(1) The perceptual knowledge that arises when writers learn how to construct valid mental representations of readers / users, once set in motion, appears to become a sort of procedural knowledge that crosses both genre and situational boundaries. When writers learn how to effectively imagine and predict reader reactions in one genre or situation, they appear able to apply that knowledge to other genres and situations. Schriver (1989, p. 250) raises this possibility when she notes that the students who participated in the control groups (i.e., were exposed to the PAM method) transferred their ability to detect document problems from one genre and audience (computer manuals for instruction) to another (elementary science texts written for lay people). In this respect, being exposed to Protocol-Assisted Modeling may impact the construction of professional writers' identities in ways which have yet to be uncovered. (2) The PAM method can also be used to help speakers of additional languages gain access to the hidden indexicalities that make their mastery of writing in a foreign language so problematical. Writing skillfully and with legitimacy is clearly not a question of just learning the relevant genres' surface features, but is also highly dependent on a writer's ability to access what is both implicit and inferred, and wield that in contextually appropriate ways. While gaining access to the indexical knowledge that acts as a 'gatekeeper' for institutional

Figure 1 :

 1 Figure 1: An excerpt from a problematic document

  Invoke M-X Text Mode to enter Text mode. See section 20.1 [Major Modes], p. 85. M-X Text Mode causes Tab to run the function ˆR Tab to Tab Stop, which allows you to set any tab stops with M-X Edit Tab Stops (See section 11.3 [Indentation], p. 46). Features concerned with comments in programs are turned off except when explicitly invoked. Automatic display of parenthesis matching is turned off, which is what most people want. Finally, the syntax table is changed so that periods are not considered part of a word, while apostrophes, backspaces and underlines are. If you are editing input for the text justifier TEX, you might want to use TEX mode instead of Text mode. See the file INFO: ETEX. INFO

Figure 2 .

 2 Figure 2. First guided writing task, given after students read the original document

Figure 3 .

 3 Figure 3. An excerpt from a think-aloud usability protocol transcript

Figure 4 .

 4 Figure 4. Second guided writing task, given after students read the think-aloud protocol transcript

  Commands for English text. EMACS enables you to manipulate words, sentences, or paragraphs of text. These commands sound like ones I'd use all the time, good. In addition, there're commands to fill text, and convert case. I don't know what it means to fill text, I guess it means putting data from one text into another … that is, filling the text with what you want in it. Well, I guess I'll soon find out.

  If you are editing input for the text justifier TEX you might want to use TEX mode instead of text mode. See the file info etex info.Well, I don't want to edit input for the text justifier mode, I just want to figure out how to manipulate words and paragraphs. Like it says up here (points to top of section). This stuff is too complicated and it's aggravating to read.

Figure 5 .

 5 Figure 5. Length of written responses over time Number of PAM exercises Number of words per response

Well, I don't know what text mode or fundamental mode is, so how will I know which I'm in? Let's see

… Invoke MX text mode to enter text mode. I won't

do that because I don't have time to see the other section. That's terrible to tell me to… See

  section 20.1 major modes page 85 MX text mode cause tab to run the function ˆR tab to tab stop. Now

wait a minute, what is all this stuff? Sounds important, but I have no idea what it could mean. I know what tabs on a typewriter are, and I see a tab key here, but what the heck does running the function ˆR tab to tab stop mean? Oh god, now they want me to look up another section…

which allows you to set any tab stops with MX edit tab stops see section 11.3 indentation page 46… Just to get started in this one. No I think I'll skip that. I'

ll deal with it when I have to use it. I thought this section was on how to edit. What does setting tab stops have to do with editing

? Features concerned with comments in programs are turned off except when explicitly invoked. Hmmm… a feature?

Wonder what a comment feature is? How do they get turned off? Do I have to turn them off? Well I guess I can't turn them off if I don't know what they are

. Automatic display of parenthesis matching is turned off, which is what most people want. What

does that mean? How do I know if I'm like most people and want them turned off? I wish they'd tell me why I need to know all these hacker terms!

  Finally the syntax table is changed so that periods are not considered part of a word, while apostrophes, backspaces and underlines are.

Syntax table… no idea. Of course, I do know what the syntax of sentences are, so maybe it means something to do with certain commands EMACS considers acceptable… maybe certain actions in a row produce a correct syntax.