Published in 2013 in Krassimira Daskalova and Kornelia Slavova Gendering Popular Culture: Perspectives from Eastern Europe and the West. Sofia : Polis, pp 239-257.

Aliens as an Invasive Reproductive Power in Science Fiction

Marika Moisseeff

Tenure Research Fellow, CNRS/Laboratoire d'Anthropologie Sociale, Paris It is worth noticing that the words "East", "West", "North" and "South" are abundantly used in the media and in geopolitics to emphasise major cultural differences. It is also significant that explanations regarding these cultural differences increasingly refer to differences in the treatment of women: at present and for some time now, the construction of stereotypes regarding cultural distinctions between "Eastern" and "Western" societies, or between "Northern" and "Southern" societies, make use of gender issues. The West is held to have rendered "their" women free, free to pursue careers until recently restricted to men, free to experience a better sexual life. These achievements in both the professional and sexual domains are in turn linked to Westerners' abilities to control reproduction and to separate it from erotic activities. The analysis of works of science fiction will allow me to show how popular representations of reproduction are used to portray cultural differences metaphorically as differences between species, thereby justifying the idea of a clash of "civilizations". 1 An important part of my anthropological research on the ideology underlying contemporary Western representations of procreation is linked to my dual training. I studied medicine (later psychiatry) and cultural anthropology at the same time, in two different universities. Going back and forth between these two disciplines quickly led me to become aware of the highly contrasting ways we have of speaking about sexual differences and reproduction, according to whom we, Westerners, are referring to: ourselves or Others, that is, members of exotic societies studied by anthropologists. At the same time, I could not but notice the pervasive effect the popular version of the Darwinian evolutionist perspective has on the way Westerners perceive these Others, those they, we, so kindly tend to qualify as "primitive" or "archaic". Indeed, we tend to approach differences between cultures in a way similar to how we treat differences between species. This is probably why we are so easily able to imagine that some "civilizations" cannot be reconciled with each other. I am of course referring here to Samuel Huntington's article The Clash of Civilizations (1993). We Westerners have a hierarchy of cultures in mind that we are usually not aware of. On the one hand, there are evolved peoples, societies, cultures -those who value sex, eroticism and control over reproduction -who really deserved to be qualified as civilized; on the other hand, there are archaic peoples, societies, cultures who, by contrast, do not only value but overvalue reproductive activities, and still worse, do so at the expense of eroticism and women's freedom.

However, in a number of science fiction works, societies of the future, having reached the highest level of evolution by virtue of their technological achievements, are pictured as susceptible to reverting to a kind of insect-like organization. The overdevelopment of technology in the realm of reproduction having led them to a state of chronic low fertility, they privilege reproduction over erotic activities and individual freedom, and make use of sophisticated biotechnology and/or inferior species in order to reproduce (see for example Science fiction authors and film makers have the gift of transforming ideology into striking images. Indeed, many contemporary, especially American academics (such as [START_REF] Jameson | Archaeologies of the Future: The Desire Called Utopia and Other Science Fictions[END_REF], Sharp 2007[START_REF] Valantin | Hollywood, le Pentagone et Washington. Les trois acteurs d'une stratégie globale[END_REF] have stressed the role played by sciencefiction in bringing to light critical issues concerning the future of the West, now that the socialist and communist utopias have petered out. Analysing the representations conveyed by works of science fiction provides access to their underlying ideology. Thus, in biology, species are distinguished and hierarchically ordered according to their respective modes of reproduction. However, such considerations also tend to be used, often without our being aware of it, to classify human societies as more or less humanised. In my view, cultural representations of reproduction are particularly useful for analysing how Western societies define themselves with regard to other societies, and more specifically, how they define cultural otherness as grounded in biological differences. It also helps to explain why gender issues tend to be systematically articulated with ways of conceiving cultural differences.

The advent of a Brave New World

In the West, what is presumed to provide freedom and equality to women with respect to men is society's ability to free them from procreative obligations through the development of cultural capacities of control over reproduction. The development of such capacities is equated with a mastery over nature itself, leading to a higher level of culture. This perspective is certainly not a recent one in the West. Thus, in 1898, that is, just prior to the new century, Freud suggested that "it would be one of the greatest Triumphs of Mankind, one of the most concrete liberations from the constraint of Nature to which our culture is submitted, if we were able to make procreation into a voluntary and intentional act, and to separate it from the satisfaction" of sexual pleasure (1989, p. 232). In brief, it would be wonderful to be able to separate sex and reproduction.

One century later, at the very end of 1999, in the last issue prior to the new Millennium, of a French magazine Télérama (a guide for television, theatre and art exhibits which is read by all who wish to be seen as well educated), an article proposed a list of traits whereby people in the year 2100 would characterize humanity of the year 2000. Among the items mentioned was: "In the year 2000, people were born inside their mothers, like animals" (Sorg 1999: 13, italics added).

Thus, maternity, pregnancy, natural child birth, the unavoidable process of being embedded within another body in order to be born, is supposed to relegate mankind to the level of animality. This idea has to be taken seriously even if the article I am referring to was facetious. Indeed, this same notion is constantly found in works of science fiction dealing with matters of procreation. I have tried to demonstrate elsewhere that science-fiction is a new form of modern Western mythology (Moisseeff 2000(Moisseeff , 2004(Moisseeff , 2005(Moisseeff , 2008(Moisseeff , 2009(Moisseeff , 2010abc, 2011(Moisseeff , 2012a)). One of the first myths of this genre, which the just quoted text reminds us of, is Huxley's Brave New World. It was published in 1932 when new modes of procreation for human beings did not yet exist. In Brave New World, children are made in test tubes and raised in State Hatcheries and Conditioning Centres. This industrial mode of reproduction, making use of artificial uteruses, is contrasted with "viviparity", a scientific term purposely used as such by Huxley to refer to the dreadful obligation of having to pass through a female body in order to be born. For civilized human beings, in this novel, viviparity is considered to connotations that imply its current usage. be a hideous remnant of the past. It persists only in a few reservations for "savages" from which the truly civilized must be protected by electrified fences.

In this pseudo utopia -or rather dystopia -the height of civilization is sterilization for all. This is accompanied by the disappearance of family, marriage and all forms of kinship relations which have become so many obscenities. When we think of Brave New World, we tend to remember and focus on test tube babies. We often forget the importance and value attributed to sexual activities. Indeed, what is really at stake in this book is the emphasis placed on the separation between sex and reproduction through the use of contraceptive, here called "Malthusian", measures, such as condoms -French letters -and abortion. Everybody is encouraged to practice sex as much as he/she can and with as many people as possible.

Children in kindergarten, who are reluctant to join in "ordinary erotic play", are sent to a psychologist. Indeed, in this anticipatory narrative, pornography is related not to erotic activities but to natural childbirth. Thus, persons, young and old, are extremely embarrassed when the past, viviparous state of mankind is mentioned. This is what happens when the Director of Hatcheries and Conditioning questions his students, a bunch of teenagers, on the meaning of the word "parent": "There was an uneasy silence. Several of the boys blushed. They had not yet learned to draw the significant but often very fine distinction between smut and pure science. One, at last, had the courage to raise his hand.

'Human beings used to be…' He hesitated; the blood rushed to his cheeks. 'Well, they used to be viviparous.' […] The poor boy was overwhelmed with confusion.

'In brief', the Director summed up, 'the parents were the father and the mother.' The smut that was really science fell with a crash into the boys' eye-avoiding silence. Our Freud had been the first to reveal the appalling dangers of family life. The world was full of fathers -was therefore full of misery; full of mothers -therefore full of every kind of perversion from sadism to chastity; full of brothers, sisters, uncles, aunts -full of madness and suicide" (Huxley, 1994: pp 20-34).

In the motherless universe pictured by Huxley, sex reigns supreme. Chastity, on the other hand, is perceived as one of the worst perversions. Indeed, it prevents people from experiencing orgasm, one of the greatest spiritual experiences for those who are given the right to enjoy the highest degree of civilization. This was the point Freud wanted to make: in his view, the cause of most neuroses was the lack of sexual satisfaction due to fear of undesired pregnancy. In Brave New World, as tends to be the case in contemporary Western society, sex and pregnancy are presented as antithetical. In the novel, pregnancy is seen as lowering humanity to the level of bestiality. It is linked with nature, the sexual life of animals being held to be mainly concerned with reproductive goals and to be deprived of orgasm. Sex per se, without a reproductive goal, on the other hand, is portrayed as the privilege of humanity. It is "cultural" rather than "natural". And, in order to fully enjoy eroticism, true human beings, that is, supposedly the most evolved beings on Earth, should be freed from the reproductive yoke.

In our, non-fictional world, this emphasis on the separation between procreation and erotic activities has provided the basis for sexual liberation and for a symmetrization of male and female social roles. Indeed, in the present-day Western world, the more or less radical separation between sexuality and procreation (as attested by contraception, abortion and the use of new reproductive techniques) is to be seen as correlated with a will to achieve symmetry between gender roles: once the issue of procreation is removed, men and women may be appreciated as occupying status-equivalent positions. However, because of women's physiological constraints, this development creates new problems regarding society's capacity to maintain its reproductive abilities over time. Technology thus comes to be seen as an inevitable recourse for all. The remarks of a renowned French immunologist, Jean-Claude Weil, published in a very serious journal of geopolitical studies in 2004, corroborate this perspective:

"I am convinced that, very soon, reproduction will be done only in laboratories and only through in vitro procedures. The old mode of reproduction will be the exception rather than the rule. Considering the current evolution of society, this is inevitable: women pursue careers, get diplomas and, when they reach forty, they want the children they did not have the time to have before. The simple solution is to extract ova and sperm from individuals when they are eighteen in order to foresee this future parental desire. Thus, one will have fresh reproductive cells that one will be able to use as required for in vitro fertilization."

This account of new normative modes of reproduction for the future is very close to what is envisaged in Brave New World. Indeed, if Huxley was influenced by what is saw in the West of the West (he wrote this novel after a trip to California), Westerners -writers, biologists and the lot -have internalized, in turn, Huxley's myth. Thus, it appears obvious to us that the advent of the technological baby-making for all is just over the horizon.

The alien: a metaphor of the female reproductive function

Huxley's novel sets the ground for subsequent science fiction works reflecting the evolution of representations and practices linked with reproduction in Western societies where erotic activities and procreation tend to be viewed as independent spheres: if individuals are to achieve full sexual pleasure, believed to be a human prerogative, they must be "protected" from reproductive risk. Child-bearing, in turn, belongs to the preserve of the "medically assisted". The function of motherhood is placed under the authority of specialists, gynaecologists and obstetricians in particular, who are more or less exclusively in charge of this domain. At the same time, having children is not linked with access to any particularly respected social status, and the parental function does not partake of the definition of adulthood. Adult sexual identity is assumed to derive directly from one's sexual identity at birth, and the acquisition of an adult, parenting role does not require any specific procedure, aside from the act of providing pubescent individuals with effective means of contraception aimed at avoiding pregnancy (Moisseeff 1992(Moisseeff , 2012b)).

The fact that procreation is taken care of by specialized agencies, third parties set apart from the mundane world, gives rise to the possibility that procreation be represented as an autonomous entity, distinct from the relations between men and women. Pregnancy and the uterus are sacralized, occupying an ambiguous position in Western ideology: we have to master them, and control over them must be undertaken by specialists. These specialists tend to perceive and to describe pregnancy as a parasitic phenomenon, one potentially lethal for mothers. One of the greatest mysteries of immunity deals with a mother's capacity to host an alien body within her own body. When I was a medical student, we were told that if ever we were able to explain this mystery we would be able to fight cancer. Indeed, the development of cancer is due to the transformation of one's own cells into alien, foreign ones.

This state of affairs leads to representations of pregnancy as a parasitic, cancerous type of phenomenon, in which the baby is perceived as a stranger within, an invader from inner space. This is obvious in science-fiction movies of the Alien type. I am referring specifically to the four episodes of Alien 2 , whose predecessor is The Thing from another World made in 1951 (Nyby) -a remake being Carpenter's The Thing (1982) -and its prequel Prometheus (2012) made by the Alien saga's initiator, Ridley Scott.

In Alien, the enemy of the future is a gigantic insectoid species, half-insect, halfspider, whose outline is like that of a dinosaur, so as to better remind us of its primitive nature. It is a predator whose only goal is to reproduce itself at the expense of other species, especially human beings. It does not eat, nor does it copulate or excrete. It only reproduces itself by transforming its prey into cocoons in which its offspring, the content of its eggs, will develop. Here, Otherness is not the other sex, but procreation itself: Alien's deadly arsenal is its reproductive system. A face-hugger shaped like a large scorpion implants the contents of the Alien's eggs within the chest of its prey; after a very rapid development, the baby Alien hatches, bursting the chest of its host. In this case, the reproduction process is therefore not sexual: it occurs in the upper half of the body and within male and female chests alike. The reproduction is portrayed as an invader that destroys its hosts from the inside, like a cancer or a parasite.

In a way, science-fiction movies, Alien and its Hollywood avatars -Xtro (Davenport 1983), Species I (Donaldson 1995) & II (Medak 1998), The Body Snatchers (Siegel 1956, Kaufman 1978, Ferrara 1994), The Puppet Master (Schmoeller 1993), etc.-are the follow up of Brave New World. It is as if natural procreation, having been denied its rights on Earth, was trying to take revenge: it is floating somewhere in outer space waiting for the opportunity to regain its original power to threaten humanity as a whole. Paradoxically, in these worlds where female and male roles tend to have become more equal, only a woman can fight this "thing" which, in fact, is the hideous aspect -for Westerners -of Maternity itself. Its huge eggs look like externalized wombs and they are shown to be Pandora's boxes 3 from which escape thousands of demons transforming human beings into animals, that is, into slaves devoted to furthering the life force of reproduction.

At the same time, the Alien epic may be seen as an allegory of female initiation in which one can see the threefold division of rites of passage as described by [START_REF] Van Gennep | Les rites de passage[END_REF][START_REF] Van Gennep | Les rites de passage[END_REF]): separation from the ordinary society, a liminal phase during which the novice undergoes painful and terrifying ordeals, and finally, reaggregation into society with a new status. It is important to note that science fiction writers and film-makers very often use the framework of an initiation path to develop their plot. Let's consider the four episodes of the Alien saga in this light:

A young woman is taken out of her usual (earthly) environment and immersed in a wild undomesticated world (intergalactic space), where she has to undergo a number of painful ordeals in order to accede to what is, for her, a hideous aspect of femininity: maternity. During this liminal period, she passes through different initiation stages that lead her gradually to assume this other aspect of herself. She is first the nurturing mother of a kitten, then the surrogate mother of a little girl, then she is pregnant with a non human female and finally is at the origin of the first male of the Alien species. At the end of this initiation, she dies to be reborn totally metamorphosed, stronger and even more feminine than ever. She can now be reintegrated to society -the Earth -with a new status as a full-fledged woman.

The symbolism of death and rebirth, so characteristic of male initiation rites in the real world (Moisseeff 1992), is linked here with the initiation of a female, fact that suggests that in future times, in the new brave new world these films portray, women will gain superiority 2 Alien, the 8th passenger (Scott 1979), Aliens (Cameron 1986), Alien 3 (Fincher 1993), The Resurrection (Jeunet 1997).

3 Brian de Palma's film, Carrie (1972), is a masterful, more direct illustration of how terrifying women's powers are, to this day. Carrie is an innocent teenage girl frightened to death by her first menstrual blood. The rest of the story will corroborate her fears: with puberty, her innocence turns into a devilish force destroying everyone around her. over men at the condition of mastering reproduction. Alien and the heroin, Lieutenant Ripley, alias Sigourney Weaver, represent the battle between woman and her reproductive function: the woman has to become the hero of future times in order to definitely master maternity. In order to do so, she has to incorporate her animality that underlies her strength and power and then sacrifice it by killing her offspring.

Huxley's anticipation myth foresaw the yet-to-come evolution of cultural representations and practices related to reproduction in Western Countries. Indeed, erotic activities and reproduction tend to be dealt with as two separate domains almost independent of each other. As soon as they become fertile, individuals, and more specifically women, have to be protected from reproductive risk. Pregnancy is conceived, described and treated as a what amounts to a sexual disease and, in a number of science-fiction movies or TV series, among which those most favoured by teenagers and young adults, it is portrayed as a potentially lethal one (Moisseeff 2004(Moisseeff , 2012a)). Moreover, childbearing is often presented as a possible obstacle to sexual fulfilment, to personal realization and professional attainment. It is something that may prevent women from reaching equality with men and, more generally, may impair sexual freedom.

Peoples, cultures and societies which are not willing to control procreation, to free "their" women from the reproductive yoke, are placed on a lower rank on the evolution ladder, closer to animals. In popular representations and phrases, for example, having lots of children is sometimes seen as behaving like animals: dogs in the US, rabbits in France. The level of evolution of a society is deemed inversely proportional to its fertility rate, high fertility rates being closely linked to poverty (Malthus 1778(Malthus , 1803;;Moisseeff 2005).

East/West: prolificity versus subfertility

Western countries are those which have difficulties maintaining a viable fertility rate, all the while being the ones which most fear overpopulation. This makes sense: they fear the overpopulation of others they judge less evolved than themselves, claiming, at the same time, that overpopulation is a threat for all humankind. The West feels threatened by the fertility rates of more "primitive" countries located in the East and the South, described as archaic societies precisely because they are held to overbreed. But at the same time, the migrant populations that come from the East and the South enable Western countries to maintain a viable fertility rate, allowing for the renewal of generations, that is, a viable demography required to maintain geopolitical balance. This is not new. Jonathan Swift, in his Modest Proposal for Preventing the Children of Poor People, from being a Burthen to their Parents, published in 1729, suggested, with trenchant humour, that the babies of the poor be sold and eaten by the rich. The present-day circulation of children through international adoption gives some weight to this early analysis of the problems between the rich and the poor. It also has to do with what Foucault has called "biopolitics".

However, if we see ourselves as civilized with regard to other terrestrial peoples deemed primitive, we may also, just as well, imagine ourselves to be the "primitives" for more advanced extraterrestrial civilizations or species. This is precisely what happens in movies like The Village of the Damned.

In a number of works of science-fiction, cultural differences tend to be portrayed as similar to those between species. In this light, different planets can be seen as referring to different continents. The Earth is the territory of the real human beings, typically exemplified by Americans; they are located in the West of the West, and in the Northern hemisphere where the most evolved Westerners live. According to his view, other planets refer to continents of potential immigrants located in the South and in the East. These immigrants, these Aliens, are supposed to be much less evolved, and to have exhausted their resources; they have stayed archaic and are deprived of individual freedom because they did not try to control their reproduction. In doing so, they have endangered not only themselves but also all the human beings on Earth. In science-fiction films, these far-too prolific migrants who are supposedly less evolved than Westerners are portrayed as huge insects that have a problem of overpopulation on their planet.

Parasitism and swarming related to insects' prolific nature underlie the privileged position occupied by insects in science-fiction movies as a means of designating the horror of uncontrolled reproduction. In ordinary life, insects are very small in comparison to human beings. However for film makers, gigantic insects are perfect for portraying the threat of a swarming, parasitic invasion. A good example is the 1998 Verhoeven movie Starship Troopers. The film is inspired by a classic science fiction novel of the same name published by Robert Heinlein in 1959. However it is also a way for Verhoeven to criticize the US intervention in the first Iraqi war in 1991. In the very beginning of the movie, a professor explains to his students that insects are superior to human beings because they breed so much and in much greater quantities, and because they do not have individual selves. Gigantic arachnoids from another planet are sending asteroids to Earth in order to kill human beings and so as to be able to replace them on Earth. Indeed, they have clearly exhausted their native milieu because of their overpopulation. This is why they need to conquer other territories. At the same time, one cannot but see the metaphorisation of the first Persian Gulf war.

Another characteristic of insects that has been used by film-makers, is the transformation of the sterile individual, the larva, into a reproductive adult, an imago, by passing through the stage of chrysalis, the nymph. This insect metamorphosis is often used, in this type of movie, to describe the metamorphosis occurring at puberty: an innocent girl is thus transformed into a terrible predator whose unique goal is to have sex with a male in order to reproduce her kind. A reproductive woman, a menstruating one, is potentially dangerous: incorporating her maternal role transforms her into someone of a different species dangerous for humanity.

For example in the movie Species 1 (Donaldson 1995), the alien born from extraterrestrial DNA attains puberty by passing through the intermediary state of a chrysalis from which emerges a fully reproductive individual. Prior to this metamorphosis, the young woman is portrayed as unappealing and somewhat chubby, as is the case for many preadolescents. She also behaves in ways that often show up at this stage of life: binge eating, running away from home, looking in the mirror with the impression of undergoing horrible changes. However, when she emerges from the chrysalis, it is as a svelte, sexy assertive bombshell. Upon acquiring her reproductive capacities, what was until then an inoffensive little girl is transformed into a predator seeking sexual relations with the sole aim of reproduction. Like the praying mantis or the black widow spider, she kills her sexual partners as soon as they have fulfilled this procreative role. Once inseminated, she becomes an animal and is ready to do anything to save her offspring. Here reproduction is associated both with animality and with death. In the movie Species 2 (Medak 1998), an astronaut infected by Martian DNA can not help but make love whenever he can. His partners are immediately impregnated and moments later are killed by the explosion of their impregnated wombs; next to their corpses young boys, their offspring, suddenly appear. When the infected astronaut impregnates these women, tentacles grow out of his back, once again showing how the conjunction of sex and reproduction leads to animality.

In traditional Western representations since Antiquity, sperm is held to be produced in the bone marrow and especially in the spinal column, the penis being seen as a prolongation of the spine through which sperm flows out (Héritier 1985[START_REF] Heritier | Le sperme et le sang. De quelques théories anciennes sur leur genèse et leurs rapports[END_REF], D'Onofrio 2004). In species such as deer, the horns of males are taken to attest to the abundance of sperm they secrete. It is not for nothing that in English, to be sexually excited is to be "horny". And if the cuckold is symbolically portrayed as having horns, it is because, as Francoise Héritier (ibid.) has argued, his sperm, whose flow is blocked by the one who has replaced him in the conjugal bed, is believed to flow backwards towards his head. The horns and bony protuberances of the mutants in Species 1 and 2 that appear when insemination takes place makes use of this symbolism.

In the movies of the kind I am referring to here, sex and procreation, when linked together, are shown to be potentially lethal, annihilating. And this is also the case with the four episodes of Alien initiated by Ridley Scott.

Anthropology in the study of popular culture

In Alien and other similar films, pregnancy is likened to an inexorably fatal, parasitic occurrence affecting men as well as women: with the exception of the heroine, the male and female characters are equal in this respect and in all others (they perform similar activities together). Otherness is not represented by the difference between the sexes, but by reproduction, embodied by a monster. Indeed, the creature's name, Alien, with its various implications, clearly indicates the terrible Otherness facing humanity: stranger; different or set apart; supposedly linked to creatures from other worlds; a specimen coming from elsewhere, entering this world and having accustomed itself to its new environment; hostile; unacceptable or repellent [START_REF] Allen | Alien". The Concise Oxford Dictionary of Current English[END_REF]. It is presented as "a survivor unsullied by conscience, remorse or moral illusions" (Alien, the Eighth Passenger). And by a strange coincidence, in this science fiction world where men and women are equal and mix in all spheres, only a woman is able to combat the crazy, immoral "relic" represented by pregnancy. This new type of myth therefore brings dramatically back to life what our 'egalitarian' societies tend to conceal; that is, the primordial asymmetry favouring women by virtue of their reproductive faculty, giving them specific, exclusive powers. For if there is one constant underlying symbolic elaboration on the difference between the sexes, it is the more or less systematic correlation between women's reproductive powers and the notion of danger, of some hidden, death-dealing force.

In a number of non Western societies, the cultural elaboration of the difference between the sexes consists in a reversal of the natural asymmetry favouring women that consolidates men's social and cultural superiority (Moisseeff 2008(Moisseeff , 2010c)). In the Alien myth, the cultural elaboration of the difference between the sexes consists of creating symmetry between their social and cultural roles; paradoxically, it tends to reinforce the asymmetrical nature of male and female positions with respect to reproduction. By inventing practices such as new reproductive techniques (IVF, test-tube babies, clones) corroborating the feasibility of dissociating sexuality and procreation -that is, by setting the field of obstetrics apart from the relations between the sexes -society simply recognizes what is specific about the female reproductive function, namely gestation. Pregnancy can then be reintegrated into cultural imagery as an independent entity, cut off from its usual sexual medium, the female body. Its appearance becomes that of a beast, whose monstrous mask hides those occult, lethal female powers. Thus, in movies such as Alien, we are led to witness a battle between a female and her procreative function, a means of connecting what has previously been disconnected.

However, if this myth suggests the possibility of such a disjunction, it also provides a novel solution to this situation: a process of initiation, through which women may subjugate what have become the quasi autonomous powers inherent in their capacity from motherhood.

During all four episodes of the Alien saga, the eponymous character to be combated by the heroine -the foreigner -has the physical appearance of an extraordinary predator whose only aim is reproduction. It is a cancer-like invader, exterminating from within by penetrating the host organisms, where it develops lightning-fast. Alien's supreme weapon is pregnancy. This repugnant 'thing' with its many Hollywood avatars is no other than the hideous mask by which the modern Western world, patterned after the United States, designates the inhuman, beastly, invasive -in short, parasitic -aspect of procreation. Moreover, pregnancy, that exclusively female phase of sexual reproduction, is close to representing an almost insufferable asymmetry in a cultural universe whose proclaimed ideal is to achieve perfect symmetry in gender roles. Medical science has successfully taken over this problem: making babies outside their mother's womb is apparently a particularly adequate solution. It is as though medical agencies have appropriated the female reproductive function, thanks to their increasingly sophisticated technology and the growing power it gives them in this sphere.

After all, the idea of men appropriating female reproductive powers is a rather commonplace theme in anthropology. It is easily found in the rituals and myths of more traditional cultural contexts, where it serves to justify the superiority of men as a group, notably with respect to fertility (Moisseeff 2010c).

In the Alien myth too, it is men (scientific officers working for a mercantile Company, and soldiers) who attempt to monopolize the reproductive function by capturing the creature.

However, the difference is that they are systematically and unambiguously depicted as the bad guys. Indeed, one of the paradoxes of Western culture resides in its association of reproduction -represented here by Alien -not so much with the perpetuation of the species as with its destruction. A connection should be made between the fictional beast's extraordinary ability to proliferate, ability which underlies its phenomenal destructiveness, and the constantly hammered theme, in real life, of the threat of annihilation by overpopulation. As opposed to the general assumption that holds sway in traditional societies, in the Western world, and for some time now (see Malthus and Swift), misfortune and poverty tends to be associated with excessive fertility 4 rather than with sterility.

Controlling the access of the poor, the "under-civilized", to reproduction by controlling the wombs of their women is indeed one of the primary objectives of the "civilized" world (United Nations 1995, Paltrinieri 2010) 5 . With sterilization viewed as an efficient means of warding off the supposedly dramatic risks entailed by the global overpopulation to which unbridled natural reproduction would allegedly expose the human race, one has the uneasy impression that Huxley's brave new world, foreseen in 1932 6 , will soon be upon us. In that dystopian state of affairs, only a few savages surviving in faraway reservations still resort to the womb, to the great displeasure of the "civilized" world whose favourite motto is "civilization is sterilization". The corollary of this development is unrestricted access to sexual pleasure. Thus in Brave New World, the civilized indulge in unlimited erotic enjoyment, free of any risk of pregnancy, with babies being produced in test tubes or cloned in "incubation" and "conditioning" centres. This shows how prophetic science fiction can be and demands that we recognize it as an anthropological object in its own right.

(1995) as: "Excessive fertility (in a couple or a nation)". In the exotic societies studied by anthropologists, fertility is hardly ever and possibly never spoken of as excessive. The existence of this notion in modern western societies, and definitely in our society, as indicated by this French term and the English equivalent, is associated not only with a form of malady, but also with animality. One occasionally hears people say: "Those people act like animals". The fact that rabbits are extremely prolific qualifies them as metaphors for both the affliction of excessive fertility and the animality on which such behaviour confines. A very peculiar affliction indeed, since it is supposed to affect not only couples but also whole peoples, incidentally those who have not reached a par for civilization: the poor, the savages, the "developing". 5 It is worth consulting the table of contents of the Programme of Action of the United Nations International Conference on Population & Development on line (http://www.iisd.ca/Cairo/program/p00000.html) as evidence of a clear articulation between Malthusian perspectives and biopolitics. 6 It should be recalled that Huxley believed that the risk of having a "dictatorship of scientists" set up to impose widespread sterilization would be an unavoidable consequence of overpopulation, as he explicitly showed in Brave New World Revisited, published in 1958.

  Rilla's The Village of theDamned [1960] and Carpenter's 1995 remake based on the 1957 novel The Midwich Cuckoos by John Wyndham). Now, in contemporary Western ideology, state control over reproduction is one of the major characteristics of totalitarian societies, symbolically comparable to insect societies (see, among others, the movies The Savage Bees [Geller 1976], Marabunta, Killer Ants [Charleston and Manasse 1998], Antz [Darnell and Johnson 1998]).

'

  Mother,' he repeated loudly, rubbing in the science […]. 'These', he said gravely, 'are unpleasant facts; I know it. But, then, most historical facts are unpleasant.' […] ('For you must remember that in those days of gross viviparous reproduction, children were always brought up by their parents and not in State Conditioning Centres.') [...] 'Try to realize what it was like to have a viviparous mother.' That smutty word again. […] 'Try to imagine what "living with one's family" meant.' They tried; but obviously without the smallest success. 'And do you know what a "home" was? They shook their heads. […] home was as squalid psychically as physically. Psychically, it was a rabbit hole, a midden, hot with the frictions of tightly packed life, reeking with emotion. What suffocating intimacies, what dangerous, insane obscene relationships between the members of the family group! Maniacally, the mother brooded over her children (her children) … brooded over them like a cat over its kittens […].

The word "civilization" is no longer used in present day anthropology because of the almost inevitably racist


THE INVISIBLE WORLD : LADAKHIS AND ILLNESS Patrick Kaplanian

In the 1970"s, gradually, through conversations with both farmers and scholars, through the analysis of various rituals and further explanations I obtained fromLadakhis (concerning, for instance, shrines to local gods (lhatho; lha-tho) and spirits of the earth or water (lhubang: klu-bang sometimes klu-khang)), the supernatural world including ideas about witchcraftbegan to unfold before me.

However, what originally drew my attention to these questions was illness, because most of the time it is ascribed to a tsan(btsan, a red demon), a gyapo(rgyal-po, another deity who curses the robbers), a witch or the like. After a circumstantial study of all the phenomena I was able to witness and listeningof the interpretations the Ladakhis gave of them, a keynotion became apparent to me, that of snotpa or notpa (gnod-pa).

The Ladakhis call (s)notpa(gnod-pa)also called rdon (gdon), skyon or gek (bgegs) any form of damage caused by a supernatural entity. This can range from drought, poverty, the death of animals, etc. to physical or mental illness. (s)Notpa can manifest in many other ways: a violent gust of wind that destroys crops, a wolf who enters a house are other forms it can take besides illness. However the Ladakhis concede that illness is not always a result of (s)notpa. They say that there are some 80,000 different kinds of (s)notpa. This is doubtless a fanciful figure intended to reflect the countless entities and supernatural occurrences that can cause (s)notpa.

Illness caused by (s)notpais opposed to natural disorders. According to traditional Tibetan medicine (which Ladakhis follow, see Meyer, 1981: 146-147) there are 404 kinds of disorders, subdivided as follows: 101 are considered incurable, 101 are curable by medicine, 101 cure on their own and 101 are (s)notparelated. Since an educated Ladakhi volunteered the same information, this fourfold division obviously applies in Ladakh too.

Other people, such as the amchi of Yurtung (Leh), extend this figure to 424 diseases and believe they are chiefly due to natural causes, (s)notparemaining an exception.

Ladakhis adhere to the Tibetan classification of diseases into two major categories, those originating from natural causes and those caused by (s)notpa. Naturally-caused diseases are strictly the domain of the amchi (am-chi) or smanba (sman-pa, sman meaning remedy), the traditional Tibetan doctor. (s)notpa-related disorders are referred to the monk, oracle (lhaba; lha-pa) and notably to the astrologer. The Ladakhis all agree on one point: (s)notpadiseases cannot be cured by the amchi's remedies alone and therefore require religious ceremonies (skurim or rimdro; rim-gro). In some cases these ceremonies suffice, in others, the amchi's treatment is also needed. The skurim is therefore a necessary measure but not always sufficient in the case of (s)notpa.

In Ladakh, like most Lamaist societies, popular and scholarly cultures constantly interact and it is virtually impossible to dissociate one from the other. Elements of scholarly knowledge pop up in almost every conversation, even that of the illiterate and inversely, the scholar's discourse is always impregnated with popular beliefs. This is not surprising since the scholars' and the lay world are intimately intertwined: the amchisand onposare village notables, monks come from peasant families; hence farmers and scholars meet on a regular basis. As long as you base yourself on conversations with Ladakhis, you will find that they conform to what is written in the texts and claim that almost all diseases arise from natural causes, (s)notpabeing a rare exception. This is all very well, but I had learned not to take my informants' declarations at face value, because I had long realized that what they professed to believe did not always correspond to their actual behavior.

Several occurrences showed me that they believed in (s)notpamore than they liked to admit. I will relate here two such instances.

1)

Like others I interviewed, S.T., an illiterate goldsmith living in Chilling, assured me without giving any figures, that illnesses due to natural causes were by far the most numerous and that those caused by supernatural entities were very rare, even exceptional.

He definitely did not obtain this information from texts (which he could not read) but, more likely, from scholars who came to visit him. A week later, when he told me his three-year old daughter had fallen ill, I innocently advised him to go and see a doctor. He refused as he was convinced she would be cured, at the latest the following day, because he had already called upon a lama to perform a skurim. The girl's condition worsened (she had chicken pox) and so S.T. finally consulted the amchi. However he persisted in believing that the illness was not "natural", and with no valid reason, remained obstinately convinced that it was due to (s)notpa. At length, the child was taken to the hospital where she eventually recovered. S.T. never doubted for a minute that he had taken the right course of action and that, without the skurim, modern medicine would have been ineffective.

2)

The following anecdote is most revealing. M.T. has studied at university and now holds an interesting and stable position. He can read, write and speak fluent Tibetan, Urdu and English. In all these ways, he is the opposite of S.T. Furthermore, he married a girl out of love and against the girl"s parents will -which suggests a great deal of emancipation from traditional Ladakhi ways. He ran away with his wife to Chandigarh in order to be married by the Indian civil administration. When they returned, his wife reconciled herself with part of her family (an aunt) and a traditional wedding was arranged to "legalize" their situation in the aunt"s house. The night before the wedding, M.T. showed signs of discomfort: he had a little fever and pains in his back and legs. I asked him whether this wasn't (s)notpa. He brushed my question aside and asked me for some medicine. I did not have any so he went off to bed. The next day, the wedding took place as planned with no particular incident. You can imagine my surprise when, about ten days later, I met M.T. again during a session at a lhamo's (oracle). When the consultation was over, he told me, somewhat embarrassed, that he was afflicted with mirdeches (mi-bde-byas), a sense of ill-being that often heralds possession by a spirit. He explained that another girl was in love with him and that her mother being a gongmo (a kind of witch whose soul possess the body of her victim), there was a good chance that she had become one too, after she had found out he had eloped with another. He admitted that he believed that he was the victim of the neglected girl's attempts to possess him.

These examples (and there are many more I could give) seem to show that the Ladakhis, despite scholarly knowledge, give a greater importance to (s)notpathan to natural causes. This irrefutable fact is not only due to the amchis' poor standards or to their tendency to prescribe skurim rather than their own remedies (sman); one must also take into account the multitudes of supernatural entities liable to cause (s)notpa. The daughter of S.T., a traditional mind, ends up in hospital. M.T., a more modern-minded man, first asks for medicine and then goes to see a lhamo.That Ladakhis are paradoxical is putting it mildly! I related S.T.'s story to my friend Phuntsok, a practitioner of Western medicine who once cured me and to whom 1 bring medicine every time I go to Ladakh. "It's always the same!" he exclaimed, "they try everything, the astrologer, the amchi, the lama, the oracle and only in desperation do they turn to us, but often, by that time, it's already too late."

Let us say a few words to introduce the different kind of healers.

The amchis

In Lamayuru Norbu is a young fellow in his twenties, who has inherited his profession from his father, as is usually the case. He is not one of the lucky few who have had the opportunity to complete the training offered by his father either in Lhasa, at the wellrespected medical College, or at the Astro-medical Institute in Dharamsala, capital of the Tibetan Government in exile.

" Meme T.G., the old amchi of Stok, claims that pulse diagnosis and urine analysis are enough to immediately determine whether the disease is natural or (s)notparelated.

However, with the exception of mirdeches, which I will discuss in further detail below, most amchis rely on more empirical methods. For instance, A.T. believes that since, a priori, doubt always prevails, the onpo (astrologer) should always be consulted first. For H.T, from Sabu, however, the failure of medicine to cure a disease is always a clear indication of (s)notpa. As for amchi P. who lives in Shankar, he is even more pragmatic and uses both medicine and skurim simultaneously. "In this way", he says, "the patient is sure to recover!" If onpo, lama and their skrurim fail, one may still call upon the rinpoche (rin-po-che) as a last resort. And when all else fails, there remains one last remedy: meditation (tshams).

Although we may find it unusual, the use of spiritual methods combined with traditional medicine when faced with (s)notpais quite within accepted norms. The great Tibetan Medical Treaty devotes an entire chapter on spirit-related disorders. Obviously, from a theoretical point of view, Tibetan and Western medicine do not have much in common.

The Tibetan system is based on simple notions such as the balance between the three bodily humors: air or wind (lung spelt rlung meaning both air and wind) bile and phlegm.

For a general outline of traditional Tibetan medicine, I will refer the reader to the work of Fernand Meyer, an acclaimed French Tibetologist, who is also a doctor in Western medicine. The following passage is taken from his study Gso-ba-rig-pas, Le Système Médical Tibétain (published by the CNRS, 1981).

Firstly, a child is not born from the fusion of sperm and an ovum but from the merging of sperm and menstrual blood. According to popular belief, the bones are formed from the sperm and the flesh and skin from the mother's blood. A proverb says ame thrak abe rus (ama'i thrag aba'i rus), "the blood of the mother, the bones of the father". When Ladakhis talk of nobility, they speak of rus, bones, and one inherits rank, title and bones from one's father (whereas we talk of "blue blood"). According to the medical tantras, if there is more blood than sperm, the child will be a girl and if there is more sperm, it will be a boy.

The body's proper functioning depends on the delicate balance between the three basic elements, wind, bile and phlegm, which are located, in specific quantities, in different parts of the body. Disorders arise when this balance is disturbed. For instance, you are a wind (lung) victim if the wind in your body is not where it should be and/or in inadequate quantities.

Amchisestablish a diagnosis by pulse reading and urine analysis. Recovery is most often obtained with medicinal plants. "This is one of our tragedies", Norbu told us, "most of the plants we use do not grow here and we have to rely on the Indians or the Nepalese to obtain them".

Astrologers

There are two types of astrologers (onpo; dbon-po): those who work with calculations and those who practice divination (mopa, mo meaning divination). Both might make mistakes at times but, no matter, there is always an explanation for any error that they might make. For instance, the mopashave a simple though rather unusual story concerning their Book of Divination (mospe; mo-dpe) in case of a mistake: one day, a wicked witch threw the book into the fire and when the legendary hero Kesar managed to retrieve it, half had already been consumed by the flames. This is why the mopas' predictions are correct only fifty percent of the time.

Rtsikspasare astrologers as we know them in the West: according to dates, time, the position of planets and stars, they determine the future of a newborn baby, the favorable day for a wedding, etc. To the same end,mopa throws dice and interprets their position, according to the famous book mentioned above.

Astrologers, soothsayers and even monks engage in the practice of exorcism and use one of the two following methods:

-either the exorcist makes a statuette representing the demon the victim is persecuted by, and then destroys it; the demon supposedly suffers a similar fate. This statuette is called storma (gtor-ma);

-or he shapes a figurine, this time representing the victim. Deceived into believing that the effigy is the actual victim, the demon throws himself onto it and the real victim is thus released. This figurine is called lut(glud), sometimes translated into English by ransom.

"Psychological" categories

Here a note of caution must be sounded concerning Western psychological terminology which cannot, in any way, be applied to Ladakhis. Even though men and women are basically similar throughout the world, they abide by laws and regulations inherent to their own culture and these differ from one culture to another. This fact becomes even more obvious when one has to compare two radically different cultures. Consequently, I will only use terms such as "psychology" or "concept" sparingly and I do not use them in reference to a notion of the subconscious.

The existence of malevolent entities alone does not entirely explain the damage they occasion. In addition, there are a number of abstract categories or psychological conditions favoring the manifestation of (s)notpa. These subjective conditions must be distinguished from direct causes such as injuring a lhu (klu, underground deity) or soiling his abode (lhusa), perceiving a tsan (btsan, red devil without back) from behind, performing a ceremony (skurim) incorrectly, or disregarding the restrictions which follow birth or death.

One such notion is that of namstok (rnam-rtog), which I will temporarily translate as "belief" or "faith". If a person does not believe in those entities (the lha, lhu, tsan, etc.) he or she cannot be a victim of (s)notpa. One often hears the Ladakhis say: rangrang seme namstok, "It depends on the person's namstok, namstok medna dra met, "no namstok, no enemies", namstok medna ch(i)an metk(y)ak "if there is no namstok, then nothing can happen".

According to S.G., a monk of high rank, this is not altogether true. Lack of namstok might protect you fromtsan, witches and the like, but not from the Ihu and other powerful deities such as higher-ranking gods likegyapo. F.E., from Sakti, at first claimed that there was no exception to the rule before conceding that (s)notpa could sometimes be inflicted by a very powerful lhu or choskyong, whether you believed in them or not.

For others, however, the rule suffers no exception: the occurrence of (s)notpadepends entirely on faith in the entitles which provoke it. Meme R, from Sabu, told me that he is hardly able to walk now because of a lhu. One of his employees cut the branch of a tree that happened to be a lhalchang, a tree inhabited by a lha or a lhu. The employee, being a Muslim, did not believe in them and therefore suffered no harm. However, Meme R., who does believe in them, is almost completely paralyzed from the waist down. T.P, from Skara goes so far as to include belief in astrology as a determining factor. He told me of a man who married on the most inauspicious day of the year (ngang-pa tozom, ngang-pa 'tgo-dzom). His father was furious but the son could not care less and thus nothing happened to him. Today, both he and his wife are in excellent health and have many children. Moreover he has become one of the richest men in the country. According to T.P., if his son had believed in astrology, things would not have turned out so well.

It would be misleading to speak of namstok in terms of superstition and conditioning.

Faith, as irrational as it may seem, is not superstition. The objective existence of demons (rdut; bdut or dre; "dre) causing (s)notpais never questioned. However they are rampant only in the presence of namstok. In addition to the notion of faith, the term namstok also conveys the notion of fear these revengeful entities inspire. "If, while I am quietly writing, a gust of wind suddenly blows my window open and if, at that moment, I am seized with fear, it is a sign of namstok, and a demon will surely sense it and attack me", Wangchuk told me.

Thus, both faith in these various deities and the fear they inspire as a result are expressed by the same term, namstok. K.T. told me the following episode from the life of Milarepa, which conveniently illustrates this point. One day Milarepa reached the foot of a mountain where he came upon a cave. He wondered what kind of creature dwelt in it and despite his high spiritual powers he was filled with apprehension. A demon came out of the cave and grabbed Milarepa by his big toe. "Why do you wish to trouble me?" asked Milarepa. "I do not wish to trouble anyone", answered the demon, "but I can't help attacking someone who has namstok". (s)Parka also conveys our notion of morale. A good morale can be understood in terms of high (s)parka. Similarly, low morale can be described as low (s)parka. However, (s)parka is not an entirely subjective factor: contact with impurity, with a low-caste person for instance, will lower the (s)parka of the one who becomes contaminated. deliberately used so that the prayer printed on the flag may be released to the four quarters of the universe. When a person has low (s)parka,an additional flag is hoisted on the roof top. The higher, the better the chance of recovery. For more effect, one may also add one's name and even astrological sign (lostak; lo, year; stak, sign). According to some, rubbing one's forehead with the flag is also helpful as the forehead is the seat of(s)parka.

When someone is seriously ill, as many flags as the ailing person's age should be planted on a hill top. This will undoubtedly cure him. The name of the actual flag (without the pole) is lotrang (lo-grangs, lo meaning year) and refers to this custom.

We can gather from these examples that (s)parkais related to the concept of high and low:

(s)parka is said to be high or low, and to rise or fall. from Nubra opposes these two notions even more radically, saying that, as you may have no namstok, i.e. no "faith" or -"belief" in (s)parka, namstok is above (s)parka.

Certain (s)notpadevelop from a general feeling of ill-being, called mirdeches (mi-bdebyas), stemming from the word rdemo or ldemo (bde-mo) signifying "beautiful". This illbeing is generally characterized by insomnia, nightmares, as well as diffuse pains.

Mirdeches is characterized by its sudden irruption and, for this reason, is associated with another notion, parchat. Parchat (bar-chad) is the element which disrupts the normal course of events, the obstacle created by a hostile force. For instance, distraction in meditation can be ascribed to a dre. Mirdeches is a form of parchat, the brutal, unexpected interruption of a normal routine. Mirdeches, by its suddenness, indicates the presence of (s)notpaand can be explained as follows: the heart, seat of all emotions and thought is affected; consequently, mirdeches is the forerunner of possession and as such, already part of this "illness". Thus, the term mirdeches is used as aneuphemism to indicate that someone is possessed or is a victim of a disorder related to possession.

We can say that mirdeches is a symptom or parchat which, by its very abruptness, betrays the presence of (s)notpa. On a more general level we can deduce that all forms of parchat, any accident, sudden illness and even sudden death, are likely to be a sign -or result -of (s)notpa. Ladakhis, whether they actually acknowledge it or not, ascribe all mishap, from the most insignificant to the gravest, to supernatural entities and agree that their nefarious influence can only be undone by a qualified expert such as an astrologer, a lhaba or a lama. Western medicine therefore is only used in last resort and is not likely to make a successful breakthrough in this part of the world*.

*I give the ladakhi pronunciation followed by the transliteration of orthography in Classical written Tibetan.

I thank Sophie Day for rereading this paper and correcting my English.

  (s)Parka (par-kha) is another "psychological" factor which also explains the effectiveness of demons and other supernatural entitles. Like namstok, (s)parkais a difficult word to translate. By (s)parka, the Ladakhis generally mean spiritual power. A monk, a scholar well-read in Buddhist scriptures, is almost by definition a person endowed with high (s)parka. A spiritually weak person has low or very low(s)parka. Thus the strong and brave hero is distinguished by an exceptionally high (s)parkaand curiously enough, this very hero is usually none other than the well-read and devoted monk himself. A Ladakhi legend tells how one day, a great warrior from Yarkand came to Ladakh with the intention of defying the strongest Ladakhi in combat. The warrior appeared to be invincible and the king of Ladakh became afraid about the future of his kingdom.Meanwhile, a monk returning from Tibet stopped by a bridge in construction. He helped the workers by removing, unaided, a huge boulder that they had been trying to displace in vain. His exploit earned him instant fame. So the king sent for him immediately and the monk defeated the Yarkandi warrior within a few seconds.

  (s)Parka finds its physical expression in the prayer flags or tarchok (dar-lchog) one sees floating above all the houses. Their five different colors indicate the five different directions. Each flag carries the image of a wind horse (lungta; rlunta) bearing a gem on his back, surrounded by mantra syllables (sngaks; sngags). Low quality material is

  One does not have to inherit the profession from one's father", Norbu explains, "anyone

can receive the teachings here, and then, if he has the means, go to college". He pretended to ignore what I already knew, that hereditary amchis, the gyut-amchis (gyut spelt brgyud means lineage) are considered to be the best. One who cannot boast a long lineage of amchisin his family has little chance of gaining widespread recognition. Open-minded as he is, Norbu is interested in Western medicine and even has a stethoscope of his own, which he apparently knows how to use. He has no qualms about using Western medicine imported by the Kashmiri nurses and even asked me for some. "True enough", Norbu tells us, "not all Ladakhi doctors are amchis. Those who work in the hospital in Leh or Kargil have a degree in Western medicine. But it is not as though we live in two separate worlds". This may be true as far as doctors like Norbu are concerned, but further investigation was to question this point of view. Amchisare far closer in their ways to those Involved in exorcism and possession than to Western doctors.

  This notion is concretely expressed by placing flags in elevated places. H.T. from Nubra told me he once trekked up a Insofar as they are shapeless shadows, they are immaterial, invisible and powerless. Only a person with low (s)parka, for example, affected by namstok, becomes visible and in potential danger.On a more general level, (s)parkaalso affectsgongmoduring possession. If a woman is bewitched by another, this means that her (s)parkais lower than that of the woman possessing her. One way of neutralizing a gongmo consists in lowering her (s)parka.

	Thus, you can be malicious and still have a relatively high (s)parka.
	Low (s)parkaand namstok are therefore two subjective conditions favoring the
	mountain to erect a flag. Certain dreams are also associated with (s)parka: if you dream
	you are falling from a cliff or mountain, it means that your (s)parka is low.
	A person with a high (s)parka, a monk or highly spiritually realized person, will not be

endangered if he meets a tsan, he won't even see him. Again, this does not mean that such entities are non-existent, but simply, that, in certain circumstances, they are harmless, even invisible. development of (s)notpa. It is important, however, not to confuse them. In both cases, high (s)parkaor lack of namstok, the demons become harmless, even invisible. However, the notion of namstok is stronger than that of (s)parka, as an onpo living in Zanskar explained to me: someone who has a high (s)parka can be attacked if he has namstok (and this is precisely what happened to Milarepa in the anecdote above). A former monk


Nesrine Changuel

Madalina Ene

Bessem Sayadi

Michel Kieffer

CLASS-BASED MDP FOR IMPROVED MULTIMEDIA TRANSMISSION OVER LTE

Keywords: Video, 4G mobile communication, optimization

This paper proposes an improved cross-layer control mechanism to efficiently stream videos to mobile users over an LTE network. A proxy-based filtering algorithm among scalable layers is considered to decide the number of SVC layers to transmit for each frame according to the communication conditions and to the class to which the video belongs to. The problem is cast in the context of Markov Decision Processes which allow the design of foresighted policies maximizing some long-term accumulated reward. Optimal actions to apply to the system are obtained by reinforcement learning. The proposed solution is implemented in an LTE simulation platform. Experiments show the performance of the proposed class-based layer filtering algorithm for a single video transmission and its robustness to content changes.

INTRODUCTION

Today, we are facing an explosion of the video traffic on wireless network due to the proliferation of multimedia-friendly portable devices [START_REF]Cisco visual networking index: Forecast and methodology, 2008-2013[END_REF]. This trend is expected to intensify further in the near future. Even if the rates provided by nextgeneration mobile networks are increasing, the demand for high-quality multimedia content is growing faster [START_REF] Amram | QoE-based transport optimization for video delivery over next generation cellular networks[END_REF].

Network congestion will be the main cause of QoS deterioration in the mobile network [START_REF]Beyond LTE: New solutions for easing escalating network congestion[END_REF]. It may occur in the wireless part, due to the nature of the wireless channel and the limited bandwidth, or in the backhaul part. Service providers need to find solutions to deliver multimedia contents in the most efficient way to provide users with the best quality of experience (QoE) while accounting for scarce network resources.

In the current implementation, a multimedia session is controlled either by the client, e.g., via HTTP adaptive streaming [START_REF] Stockhammer | Dynamic adaptive streaming over HTTP design principles and standards[END_REF] or by the server via RTP [START_REF] Singh | Rate-control for RTP-based multimedia applications[END_REF]. In both cases, the network is not aware of the video traffic and the control of any congestion in the network relies only on the way the multimedia session is managed.

Long Term Evolution (LTE) [START_REF] Sesia | The UMTS Long Term Evolution : From theory to practice[END_REF] substantially improves end-user throughputs, sector capacity and reduces user plane latency, bringing significantly improved user experience. LTE provides IP connectivity between the User Equipment (UE) and the Packet Data Network (PDN) without any disruption during mobility. LTE supports different types of services including web browsing, video streaming, VoIP, online gaming, real time video, etc. [START_REF]Top 10 considerations for a successful evolved packet core (EPC) deployment[END_REF].

In order to improve the received video quality, in the context of LTE networks, control may be done in Medium Access Control (MAC) or in PHYsical (PHY) level. In [START_REF] Luo | Qualitydriven cross-layer optimized video delivery over LTE[END_REF] a QoSaware scheduling algorithm is proposed for real time video delivery over LTE cellular networks. A cross-layer optimized system is proposed to achieve a good perceived video quality under delay constraint by dynamically adapting the resource allocation to the instantaneous channel quality. This requires scheduler adaptation in the eNodeB (eNB). In [START_REF] Pande | Qualityoriented video delivery over LTE using adaptive modulation and coding[END_REF] a qualityoriented video delivery over LTE algorithm based on modulation and coding adaptation is proposed. In this algorithm, PHY layer technologies, MIMO configuration, and MCS are dynamically adjusted.

In [START_REF] Shuaib | Smoothing of video transmission rates for an LTE network[END_REF][START_REF] Combernoux | Cross-layer optimization of a multimedia streaming system via dynamic programming[END_REF], video delivery control techniques are proposed for single-video delivery. In [START_REF] Shuaib | Smoothing of video transmission rates for an LTE network[END_REF] a smoothing buffer is used in the eNB to smooth the transmission rates with minimal information about the video to be transmitted. This approach is mapped to be used in an LTE network where a fourstate Markov channel model is used to represent the channel variations. In [START_REF] Combernoux | Cross-layer optimization of a multimedia streaming system via dynamic programming[END_REF], a cross-layer optimization of various parameters of the coding and transmission chain is performed to deliver video to mobile users. The problem is cast in a Markov Decision Process (MDP) framework [START_REF] Sutton | Reinforcement Learning: An Introduction[END_REF]. Coarse models of the source and of the channel have been considered due to the increase of complexity of the optimization algorithm with the number of state values.

In [START_REF] Changuel | Online learning for QoE-based video streaming to mobile receivers[END_REF], we proposed an online control mechanism to maximize the quality of the received video, while accounting for the source type (I, or P) of the transmitted frames. The control problem is again cast in the framework of MDP. The solution in [START_REF] Changuel | Online learning for QoE-based video streaming to mobile receivers[END_REF] was proposed for single-user video delivery with coarse description of the system characteristics. In this paper, we propose to better account for the variability of video characteristics among video streams and within a video stream. Videos are mainly characterized by their Rate-Distortion (RD) function which depends on the activity in the video, as well as the their spacial and temporal resolution. A cross-layer optimization mechanism should account for these characteristics, which have a significant impact on the user QoE. Various video classes may be defined to to take these characteristics (activity, resolution) into account. Then, the proposed solution consists in learning optimal policies for each class. This allows a finer adaptation of the policy to the video content. Determining the class a video or a frame of it belongs to may be done at the server or in the network using, e.g, [START_REF] Xu | Video classification using spatialtemporal features and PCA[END_REF][START_REF] Toderici | Finding meaning on youtube: Tag recommendation, category discovery and their implications in browsing and search[END_REF]. The proposed class-based control algorithm is implemented on an LTE simulation platform [16]. Typically, in case of 3GPP mobile network, the last buffer in a multimedia session is the Radio Link Control (RLC) layer. The RLC buffer is monitored and controlled to avoid the underflow or overflow situations which can cause disruptive or low quality of the multimedia content.

The remainder of the paper is organized as follows. Section 2 introduces the considered unicast video streaming. Section 3 details the optimization algorithm and the use of video classification. Section 4 presents the performance of the proposed class-based layer filtering process implemented on an LTE simulation platform.

SYSTEM ARCHITECTURE

Consider the video streaming system to a mobile receiver sketched in Figure 1.

Fig. 1. Proposed class-based layer filtering process using H.264/SVC in LTE network for a unicast connection

The considered system is based on the LTE network topology with an emphasis on the downlink radio access sector between the eNB and the UE. For each unicast connection, a video server hosts a scalable video coder providing L SNR layers and can be situated inside or outside the core network. Frames are generated with a constant period of time T . The video packets travel through a limited delay core LTE network to reach a Post-Encoding (PE) buffer situated in a proxy where a controller performs layer filtering. For each frame, SNR layers may be sent, kept, or dropped. The layer filtering process should maximize the video quality at the receiver side by taking into account most factors impacting it: video class, frame type, number of SNR layers, and lost packets due to possible RLC buffer overflow. Filtered layers are then sent to the eNB. The RLC buffer status in the eNB is monitored to estimate the channel state. In fact, there is one RLC buffer per radio bearer, and therefore per video service. Moreover, the RLC buffer is the last buffer in the Layer 2 protocol stack that can provide information about the data flow through the stack. The MAC scheduler, as well as its PHY layer, its radio front-end, the wireless channel, the physical layer of the receiver, and the part of the MAC layer at receiver side managing ACK/NACK procedures are considered as the channel.

LAYER FILTERING ALGORITHM

Single user layer filtering

In [START_REF] Changuel | Online learning for QoE-based video streaming to mobile receivers[END_REF] a layer filtering process for a unicast video delivery is proposed. It is cast in the MDP framework [START_REF] Sutton | Reinforcement Learning: An Introduction[END_REF]. Time is slotted into discrete-time intervals of length T . The t-th time slot is the time interval [t, t+1)T . The states of the system consist of the frame type s F and the level of the RLC buffer s R . The system state is then s = (s F , s R ) ∈ S. The actions indicate the number of scalability layers to transmit, keep or drop from the PE buffer. Action chosen at time slot t is described by the vector a t = (a ℓ,f ) t where ℓ ∈ {1, ..., L} is the layer index and f ∈ {1, ..., F } is the frame index. The possible values of a ℓ,f are 0, 1, and-1 corresponding respectively to keeping, sending, and dropping a frame. Actions corresponding to sending enhancement layers and keeping or dropping base layer of the same frame are excluded.

The effect of an action is expressed via a reward function r t (s t , a t ) depending on the PSNR or any other video quality metric [START_REF] Itu-T | Objective perceptual multimedia video quality measurement in the presence of a full reference[END_REF][START_REF] Sullivan | Rate-distortion optimization for video compression[END_REF][START_REF] Winkler | Image Analysis, Random Fields and Dynamic Monte Carlo Methods: A Mathematical Introduction[END_REF], and the level of the RLC buffer to determine the optimal policy. In absence of overflow and frame drop, the reward function provides an estimate of the video quality at the receiver

r t (s t , a t ) = L ℓ=1 max(0, a ℓ,f,t )q t (s F t , ℓ) (1)
where q s f , ℓ is the quality increment measure provided by the transmission of layer ℓ from a frame of type s F . When there is a frame drop, concealment is performed at receiver side, the video quality of the current frame is assumed to be equal to that of the previous frame reduced by a factor λ(s f ) depending on the type of the lost frame (lost I frames will have more impact on the next frames than lost P frames). One then gets

r t (s t , a t ) = r t-1 (s t-1 , a t-1 ) -λ(s F t ). (2)
The optimal foresighted policy [START_REF] Sutton | Reinforcement Learning: An Introduction[END_REF] maximizing the discounted sum of present and future rewards is evaluated through reinforcement learning (RL). In fact, unlike policy or value iteration [START_REF] Sutton | Reinforcement Learning: An Introduction[END_REF] where state transition probability are needed to find the optimal policy, RL aims at estimating a good policy without requiring knowledge of state transition probabilities which is very practical in the considered situation, where system state transition are partially unknown. RL leads to a two-phase algorithm. In the exploration phase, the system states (frame type, buffer state, channel state) are explored by taking random actions and measuring the resulting rewards. In the exploitation phase, the optimal actions learned in the exploration phase are applied as a function of the system state.

System states can be chosen with a fine granularity leading to a fine description of the system (e.g, number of PDU in the RLC buffer) and finely tuned actions. This may result in a very long exploration phase before getting the optimal action to take in each system state, see Figure 2. On the other hand, Fig. 2. Cumulative PSNR reward for foresighted policies obtained using the technique in [START_REF] Changuel | Online learning for QoE-based video streaming to mobile receivers[END_REF].

system states can be chosen with a coarse granularity leading to an averaged description of the system (using, e.g, a coarse quantization of the number of PDU in the RLC buffer) which may decrease the learning time. The second choice, considered in [START_REF] Changuel | Online learning for QoE-based video streaming to mobile receivers[END_REF], is more robust to small system changes since it corresponds to an average behavior of the system.

With this approach, video characteristics are not accurately taken into account at the learning process, and only policy optimal in average are obtained. Better tuned policies may be obtained by taking more characteristics into account.

Class-based layer filtering

In order to improve the accuracy of the solution in [START_REF] Changuel | Online learning for QoE-based video streaming to mobile receivers[END_REF], we propose to add a new state in the system model. Consider s C ∈ {1, . . . , C} corresponding to index of the class the frame, Group of Picture (GoP), or video belongs to. A video class can be considered at different granularity levels, it can be related to an entire video, or it can be updated at each frame, GoP, or set of GoPs. When considering classes at a finer granularity than the video level, the evolution of the class state may be distributed by a Markov chain as in [START_REF] Xie | Structure analysis of soccer video with hidden markov models[END_REF].

Information related to the video class can be derived in the proxy according the R-D characteristics of the stored video packets in the PE buffer or it can be defined by the server and marked in the header of the compressed flow at each time the class changes. Depending on the class s C t at time t, different policies may be used. Due to the unknown class state transition probabilities, RL is used which allows estimating a good policy without requiring an accurate knowledge of the class transition probability P (s C t+1 |s C t ).

EXPERIMENTAL RESULTS

The proposed solution consists of on the following steps: First, action-state learning matrices are derived either dynamically using the delivered flows or offline for different video classes and stored in the layer filtering block, see Figure 1.

Second, for each frame to be filtered, the video class s C t is identified. Third, the optimal policy corresponding to video class s C t is used while filtering the transmitted frame. One has to verify the robustness of the algorithm with respect to the video class.

LTE SIMULATOR

In this section we briefly describe the layer 2 of the LTE downlink link level simulator framework and the implementation of the proposed algorithm.

Open Air Interface (OAI) [16] provides an open source wireless technology platform with both hardware and software components. It hosts a prototype representative of the LTE infrastructure offering the possibility of a large scale simulation. From the packet delivery point of view, the simulation is soft real-time with an emulation which permits the existence of several instances (eNB and UE) on the same machine.

Video delivery begins at the server side where video packets are transmitted to the proxy and stored in the PE buffer. Video class as well as the frame type are assumed delivered by the server and marked in the header of the transmitted video packets. Decision making is then performed by the layer filtering control block using information about the frame type, the video class from the stored video packets and the level of the RLC buffer from the eNB. The filtered layers travel to the eNB via OAI. Once transmitted, video packets are segmented and placed in the RLC buffer. The new RLC buffer status is then fed back to the layer filtering block and the system state is updated. Based on the new system state a PSNR reward is generated and used to update the policy during the exploration phase of the RL. Then, the algorithm continues its loop.

Considered tests

The performance of the proposed layer filtering process has been evaluated with two classes (C = 2) at the video level. Foreman.qcif (Average Encoding Rate (AER) 3.1 Mbps) and Carphone.qcif (AER 3 Mbps) are considered belonging to video class s C = 1 due to their similar R-D characteristics and low activity level. Then, Football.cif (AER 5.2 Mbps), and Basket.cif (AER 5 Mbps) 100 s long both extracted from real TV programs belong to video class s C = 2, characterized by very high activity level. Video classification is performed offline; it can also be realised using [START_REF] Xie | Structure analysis of soccer video with hidden markov models[END_REF][START_REF] Zeng | Video indexing by motion activity maps[END_REF][START_REF] Xu | Video classification using spatialtemporal features and PCA[END_REF][START_REF] Toderici | Finding meaning on youtube: Tag recommendation, category discovery and their implications in browsing and search[END_REF]. The Packet Data Units (PDUs) in the RLC buffer are of variable size, depending on the the condition of the channel assigned by the eNB to the UE. The maximum number of PDU in the RLC buffer is R MAX = 128. Five states for the RLC are considered corresponding to a quantization of the number of PDU in the buffer. The intervals are [0, 0.6) R MAX , [0.6, 0.75) R MAX , [0.75, 0.85) R MAX , [0.85, 0.95) R MAX , and [0.95, 1] R MAX . The fifth interval is smaller than the others to anticipate overflow and prevent PDUs from being dropped. All videos are encoded at 30 fps using the H.264/SVC encoder (JSVM 9.19) [START_REF] Vieron | JSVM9 software[END_REF] with three MGS scalability layers per frame (L = 3). The period at which the controller is operating is T = 1/30 s. IPPP GoPs of 16 frames are considered. A base layer only control scheme [START_REF] Schwarz | Overview of the scalable video coding extension of the H.264/AVC standard[END_REF] for the encoder is adopted to minimize the drift when refinement layers are lost. Thus, two possible frame type s F are considered: I or P frame. OAI emulates the LTE channel variation and the MAC scheduler selects the appropriate Modulation Coding Scheme (MCS) so that the channel rate values range from 0.5 to 4 Mbps, the optimal action for each possible state is determined for the foresighted policy. In our simulations, no handover is considered and the receiver buffer size is assumed infinite. The robustness of the proposed approach to variations of the characteristics of the system is evaluated.

Intra-class robustness

To make sure that an optimal filtering policy learned for a video is satisfying for another sequence within the same class, intra-class robustness is evaluated. The performance of the proposed algorithm is evaluated based on the decoded PSNR received at the UE. The policy is learned using Carphone or Foreman at a channel rate of 2Mbps. These two policies are then used to filter SVC layers while transmitting Carphone sequence. Results are shown in Figure 3. The dotted Fig. 3. Decoded PSNR using Carphone and Foreman foresighted policies for different rates. curve represents the average PSNR of Carphone as a function of the channel rate. The Carphone-tuned policy applied on Carphone (no mismatch). Solid curve represents the average PSNR of Foreman -tuned policy applied on Carphone (mismatch). In case of mismatch in the same class the PSNR is slightly decreased compared to case of no mismatch.

Inter-class robustness

Inter-class robustness is now evaluated. The class of each sequence is assumed available while transmitting the video. The experiment consists in learning the three optimal foresighted policies using: Basket, Football, and then Foreman. The three policies are then applied separately on the Basket sequence. Results are shown in Figure 4. One can see that curves refer- ring to videos which fall in the same video class (Basket and Football) show a comparable behavior. On the other hand, applying the optimal actions learned with Foreman (not the same class as Basket) gives a PSNR degraded in average of 2 dB compared to using the optimal actions learned with Basket sequence. This result shows the importance of using video classes in the system state in order to consider variations of the video characteristics. Later, more videos classes will be considered to test the robustness with various video contents.

CONCLUSION

This paper proposes a cross-layer optimization solution to efficiently deliver scalable video over LTE networks. Optimal SVC layer filtering decisions are learned for different video classes in order to take into consideration the variability of the video characteristics mainly related to their rate-distortion properties, as well as their spacial and temporal resolution. The proposed algorithm is implemented on an LTE simulation platform. Intra-class robustness shows that the solution is robust for video sequences belonging to the same class. When applying a policy learned for one class to a video belonging to an other class, a more significant quality decrease is observed. This illustrates the importance of accounting for the class a video belong to in such layer filtering algorithm. More classes and more videos in each class will be considered in the final version of the paper.

Fig. 4 .

 4 Fig. 4. Decoded PSNR of Basket video using optimal foresighted policies of different video class.

This work is supported by the European Commission under the ME-DIEVAL project (grant agreement no FP7-258053). Michel Kieffer is partly supported by the Institut Universitaire de France.