An Atlas of Trafficking in Southeast Asia:

The Illegal Trade in Arms, Drugs, People, Counterfeit Goods, and Natural Resources in Mainland Southeast Asia

Introduction: Illegal Trades across National Borders

Pierre-Arnaud CHOUVY Mainland Southeast Asia-or Indochina as it has long been known owing to its position between India and China (see map 1)-has been marked by decades of trafficking in illegal goods. Illegal trades in mainland Southeast Asia are numerous, highly diverse, and most likely increasingly complex. Of course, two of the most prominent illegal trades defining the area are human trafficking and drug trafficking, human trafficking in relation, notably, to the extensive regional prostitution market it feeds, with Thailand being infamous the world over for that reason; and drug trafficking in relation to opium and heroin produced in bulk within the similarly ill-famed Golden Triangle. Complexity arises from the fact that human trafficking and drug trafficking can be said to be linked in some places and to some extent, whether drug consumption by prostitutes-and by many of their clients-is concerned or whether economic havoc created by excessively brutal and rapid eradication of illegal crops pushes women into prostitution. However, as we will see, complexity is likewise increased by the fact that many other illegal trades feed off these two major trafficking activities and their sometimes congruous networks. Some of these trades may, at some point, contribute to one another; they may also proceed, to some extent, from propitious specific regional dynamics (trafficking in drugs and arms in the context of armed conflicts for example). It is this great diversity and complexity of illegal trading across mainland Southeast Asia that this book addresses, focusing on five of its most pervasive phenomenon: drug trafficking, human trafficking, arms trafficking, wildlife and timber trafficking, and the trade in counterfeit goods and contraband.

As might be expected, the peninsular mass of mainland Southeast Asia is not only one of Asia's historical major crossroads (hence -Indochina‖ and the French Indochine). It is also famous worldwide as the site of the so-called Golden Triangle, one of the two main areas of illegal opium production in Asia and one of the largest in the world for that matter. But, insofar as illegal activities are concerned, contemporary mainland Southeast Asia is known not only as a locus of illegal drug production but also as a drug trafficking hub and a significant drug consumer market. Heroin and methamphetamine are produced mainly in Burma (also known as Myanmar since 1988) and trafficked heavily throughout the region.

Heroin and methamphetamine may be consumed regionally (both in mainland and in insular Southeast Asia) or may be exported to China (via the province of Yunnan), to India (via its northeastern states), or overseas, mostly to Japan, Australia, and North and South America (see map 13).

However, many other trafficking or smuggling activities have long occurred in and throughout mainland Southeast Asia while others are now in the process of being developed.

One of them, constantly increasing both regionally and worldwide, is human trafficking. This activity shares many features with drug trafficking and, although statistics are unreliable and trustworthy studies remain scant, it is frequently mentioned as becoming the world's largest illegal economy. Again, though, the assertion is unverifiable since no one can reasonably provide a precise estimate of the global value of drug trafficking alone [START_REF] Tom | Wages of Crime: Black Markets, Illegal Finance, and the Underworld Economy[END_REF] . In any case, Southeast Asia also experiences many other major smuggling and trafficking activities, from the international trade in small arms and in nuclear and other radioactive materials, to the international trade in illegally logged timber, forest products and wildlife. It is at once worth noting that some of these traffics can be distinguished from many others insofar as they constitute instances of environmental harm and predatory activities or both. However, while seizures conducted throughout the region attest to the existence of various and numerous smuggling and trafficking activities, the scope, diversity, nature and mechanisms of the overall phenomenon are far from being satisfactorily studied and understood. In fact, the very complexity of the phenomenon goes beyond its diversity and fast-evolving trends as the extent of the illegal trades undoubtedly exceeds what is known and understood from open or even restricted sources. This condition owes largely to the relative failure of concerned authorities and bodies, both at the national and international level, to monitor illegal movements across national borders. Yet it is also the result of a general deficit in academic research on these issues and of the segmentation of most of the research that has been undertaken. The various studies of illegal trades do not provide a regional and systemic understanding of the variety of smuggling and trafficking activities. Even less is known of the synergies that are likely to exist between drug trafficking, human smuggling and trafficking, arms trafficking, wood smuggling, etc. As Itty Abraham and Willem van Schendel explain, there is a -problem of compartmentalization, as specialists in small arms and drugs rarely communicate, and scholars of smuggling, trafficking, and money laundering have no common forum to share their insights, all preventing a comprehensive landscape of the scale of illegal activities from being visualized‖ 2 .

Still, smuggling and trafficking activities have been drawing increased attention during the past decade or so, as globalization further opened and deregulated national and regional markets. Trafficking is increasingly being presented as a growing threat in the media as well as in governmental and non-governmental reports. This is not only because, as Itty Abraham and Willem van Schendel put it, -individuals and social groups that systematically contest or bypass state controls [...] flout the letter of the law‖ and sometimes jeopardize public health (illegal drugs, counterfeit pharmaceuticals), the environment (illegal logging and poaching), social fabrics (human smuggling and trafficking), or even peace (arms trafficking). In fact, states see trafficking activities as a major threat also because smugglers and traffickers -bring into question the legitimacy of the state itself by questioning the state's ability to control its own territory‖ 3 . Whether smuggling and trafficking activities are clearly on the rise or whether greater attention has been paid by national and international authorities, the phenomenon nowadays is more and more presented as a major multi-fold and worldwide threat.

But, while globalization has undoubtedly and increasingly transformed the phenomenon during recent decades, the historical and geographical approach of notions such as borders, frontiers and routes, shows us that the phenomenon is far from being entirely new. History shows that the rise of the nation-state and its multiple regulations have directly affected various types and ways of trading by rendering them illegal. Thus, to shed some light on what is, by essence, a complex and shadowy world made of illegal and therefore absconded activities one must first understand how -the politics of access and of its denial‖ [START_REF] Mahnaz | Roads and Rivals: the Politics of Access in the Borderlands of Asia[END_REF] have been deeply affected by the modern modification of frontiers, borders, routes and regulations. But, firstly, the widely used notions of smuggling and trafficking need to be distinguished from each other and explained, in order to show that although both activities amount to illegal trading, smuggling is not trafficking.

Smuggling or trafficking?

One major distinction must be made between the different activities that amount to illegal trading. Illegal trades can be distinguished according to the nature of the goods that are exchanged as well as to the nature of the trade itself. Therefore, distinguishing between smuggling and trafficking enables us to dissociate two major types of illegal trading and to overcome the confusion of two terms that are frequently used interchangeably and without distinction. To that effect, one can build on the work of David Bevan, Paul Collier and Jan Gunning [START_REF] Bevan | Black Markets and Black Goods[END_REF] , who separate what they call -black goods‖ (goods that are illegal) and -black parallel markets‖ (where legal goods are being traded illegally). Another interesting and useful distinction has been made by Abraham and Van Schendel who -build up a distinction between what states consider to be legitimate (-legal‖) and what people involved in transnational networks consider to be legitimate (licit)‖. As the authors explain, this distinction is most useful in the context of an -approach to issues of legality and illegality which does not take the state as its point of departure‖ 6 . Yet, raising issues of legitimacy in this book would have made things even more complicated than they already were (rights of individuals to consume drugs, own guns, poach, log, mine, illegally and willingly across international border, etc.) and it was thought here that focusing on what made some cross border activities illegal according to national laws was a better choice, which does not mean that the perceptions of borders and borderlanders have been dismissed altogether.

Hereafter, smuggling will describe the importation and, or, exportation of legal goods contrary to the law of at least one country, especially when duties are not paid or when part of a regulation is not observed. As for trafficking, it will describe a trade in goods that are illegal per se; that is, a trade therefore illegal by definition. Thus trading in heroin differs greatly from trading in cigarettes since heroin is an illegal product and cigarettes are produced and sold legally. Nevertheless, cigarette smuggling is rampant in the world, for instance in the European Union, owing to great variation in duties and ages of legal consumption from country to country. Therefore, duties, regulations and prohibition partly determine the extent to which goods are smuggled or trafficked, whether locally, regionally or globally [START_REF]L'illicite dans le commerce international des marchandises[END_REF] . Of course, goods that are considered -licit‖ by people involved in transnational networks are more likely to be smuggled and, or, trafficked, than goods deemed -illicit‖, whether they are legal or not.

Usually, the difference between smuggling and trafficking is made only concerning the trade in human beings. According to the United Nations Office on Drugs and Crime (UNODC), human smuggling and human trafficking are similar in some respects, but bear several important differences. The United Nations Protocol Against the Smuggling of Migrants by Land, Sea and Air, Supplementing the United Nations Convention Against Transnational Organized Crime, defines the -smuggling of migrants‖ as -the procurement, in order to obtain, directly or indirectly, a financial or other material benefit, of the illegal entry of a person into a State Party of which the person is not a national or permanent resident.‖

The United Nations Protocol to Prevent, Suppress and Punish Trafficking in Persons defines -trafficking in persons‖ as -the recruitment, transportation, transfer, harbouring or receipt of persons, by means of the threat or use of force or other forms of coercion, of abduction, of fraud, of deception, of the abuse of power or of a position of vulnerability or of the giving or receiving of payments or benefits to achieve the consent of a person having control over another person, for the purpose of exploitation. Exploitation shall include, at a minimum, the exploitation of the prostitution of others or other forms of sexual exploitation, forced labour or services, slavery or practices similar to slavery, servitude or the removal of organs.‖ Thus, trafficked victims, according to the UNODC, -have either never consented or, if they initially consented, that consent has been rendered meaningless by the coercive, deceptive or abusive actions of the traffickers.‖ Another major difference, according to the UNODC, is that -smuggling ends with the arrival of the migrants at their destination, whereas trafficking involves the ongoing exploitation of the victims in some manner to generate illicit profits for the traffickers.‖ Thus, according to the United Nations, what distinguishes human smuggling from human trafficking, which are both illegal practices and designate illegal movements of persons, is coercion (or, alternatively, absence of consent). While both smuggled and trafficked people are illegal immigrants, only the first are compliant and complicit, unless, of course, initial consent is nullified by deception and, or, coercion [START_REF] Iselin | Distinguishing between Human Trafficking and People Smuggling[END_REF] . The extreme complexity of human smuggling and trafficking is notably determined by the fact that activities fed by illegal migration-as diverse as prostitution, mining, or even begging-can be either coerced or consented activities: prostitution can be voluntary, while forced labour can be used in mines.

Children, who are increasingly being trafficked, can be abducted to become beggars in a foreign country. Moreover, as is the case in Southeast Asia, countries are frequently source, transit and destination areas for trafficked persons, depending on the segmentation of national and regional markets [START_REF]Trafficking in Persons Report[END_REF] .

Other migrants (emigrants or immigrants) can also be said to be illegal or to have been illegally moved from one place to another, for example refugees (as immigrants) and adopted children (both as emigrants and immigrants). Refugees often cross international borders without proper paperwork but while this kind of illegal immigration is forced, it surely must not be viewed as being criminal, for a refugee, while not always benefiting from having refugee status, is frequently exposed to physical violence and economic exploitation. This is a global phenomenon, despite the United Nations High Commissioner for Refugees (UNHCR) using the 1951 Geneva Refugee Convention as its major tool to ensure the basic human rights of vulnerable persons, particularly toward guaranteeing that refugees will not be returned involuntarily to a country where they face persecution.

It is worth noting that children, being especially vulnerable, are among the first victims of human trafficking. For instance, Xin Ren alleges that -trafficking in children for sale, sexual exploitation, child pornography, and slavery labour has become one of the fastest growing global crime enterprises stretching from the African continent to Europe and from Asia-Pacific to North and South America‖. Children are being -sold, abducted, kidnapped, or lured away from their families, bought, exploited, abused or even murdered for profits and illicit services‖ [START_REF] Ren | Trafficking in Children: China and Asian Perspective, California State University, Sacramento, Conference on Making Children's Rights Work: National & International Perspectives, International Bureau for Children's Rights[END_REF] . Of course, trafficking in children can occur in various contexts, with many different push and pull factors. For example, illegal adoption is an international phenomenon in which local and global push and pull factors can be closely intertwined. Whether for domestic or international markets, -trafficking in children in China is largely for domestic illegal adoption that is driven by a deeply rooted traditional belief that only male heirs can carry on the family name and sonless marriage is a moral shame that disgraces one's ancestors‖ [START_REF] Ren | Trafficking in Children: China and Asian Perspective[END_REF] . But since legal adoption may prove extremely difficult in Western countries, because of strict laws aimed at child protection, and because regulation acts as a strong incentive for traffickers, worldwide illegal child adoption has become a highly lucrative market.

Children, as well as men and women, furthermore can be abducted, trafficked and killed for forced organ removal for transplant purposes, as high prices paid for kidneys, as just one example, drive an extremely profitable global market. However, because sex workers are in such great demand worldwide, it appears that 50% of trafficked persons in the world are children, and that 70% are women 12 . As stated by Vitit Muntarbhorn, the former UN Special Rapporteur on the Sale of Children, Child Prostitution and Child Pornography, -the world community is faced with a rampant and perverse sex market which wreaks havoc on a multitude of children‖ 13 . Indeed, ECPAT 14 , an international non-governmental organization working to -End Child Prostitution, Child Pornography and Trafficking in Children for sexual purposes‖, reports that there are more than 1 million child prostitutes involved in sex tourism in Asia, of which 300,000 are in Thailand, 100,000 in the Philippines and Taiwan and 40,000 in Vietnam 15 .

In May 2005, in a report that has been termed -the most comprehensive analysis ever undertaken by an intergovernmental organization of the facts and underlying causes of contemporary forced labour‖, the International Labour Organisation (ILO) revealed that -at least 12.3 million people were trapped in forced labour around the world‖ and that -children aged less than 18 years bear a heavy burden, comprising 40 to 50 per cent of all forced labour victims‖. If we refer to the aforementioned definition provided by the United Nations Protocol to Prevent, Suppress and Punish Trafficking in Persons, exploitation through forced labour is a fundamental dimension of human trafficking. This is something that the ILO report also points to when confirming something that had often been hinted at by less comprehensive studies: that forced labour, human trafficking and the sex industry, were closely linked. In fact, according to ILO, at least one-fifth of the world's 12 million bonded labourers are victims of illegal human trafficking-mainly for the sex industry. For instance, the report details, -Forced economic exploitation in such sectors as agriculture, construction, brick-making and informal sweatshop manufacturing is more or less evenly divided between the sexes‖. However, -forced commercial sexual exploitation entraps almost entirely women and girls‖ [START_REF]A global alliance against forced labour[END_REF] .

Smuggling and trafficking, then, are different, no matter what trade (human beings or commercial goods) is concerned. As we will see, the very dimensions and impact of smuggling and trafficking also differ, mainly depending on the consequences of the illegal trade on source, transit and destination countries. However, to better understand smuggling and trafficking activities, one first needs to learn about borders, routes, and their respective logics. Indeed, smuggling and trafficking consist of illegal border crossings made via various routes or lines of travel, namely trails, paths, roads, and the like.

Of routes, frontiers and borders: the politics of access

A border, through its definition and its delimitation processes, modifies the very nature of any traditional trading that preceded its imposition. In fact, for many merchants, activities suddenly termed smuggling or trafficking are nothing else than traditional trading turned illegal or traditional goods turned illegal; for instance -what is now called smuggling was normal among the Pashtun nomads of eastern Afghanistan for many generations‖ [START_REF] Robert | Ethnic, Regional, and Sectarian Alignments in Afghanistan[END_REF] . Indeed, according to a Pakistani Afridi from the Northwest Frontier Province (NWFP) of Pakistan:

-You might call what we do smuggling. But to us, it's just trade‖ [START_REF] Edwards | An Eye for an eye: Pakistan's Wild Frontier‖[END_REF] . Between Afghanistan and Pakistan, as well as between Burma and Thailand, imposed boundaries cut through frontier zones and tribal land, changing frontiers into borders and creating de facto jurisdictions-in effect, bounded legal territories. But boundaries also affect the very nature or existence of routes. For example, -a road through tribal territory is much more than an avenue of mobility.

Here the laws of the state intersect with the laws of the tribe‖ [START_REF] Mahnaz | Regarding borders and trafficking routes in Asia, see also: Pierre-Arnaud Chouvy[END_REF] . As David Ludden explains, -Modernity consigned human mobility to the dusty corners of archives that document the hegemonic space of national territorialism. As a result, we imagine that mobility is border crossing, as though borders came first and mobility second‖ [START_REF] Ludden | Presidential Address: Maps in the Mind and the Mobility of Asia‖[END_REF] .

As stressed in the work of Mahnaz Ispahani, a route is -both a geographical and a political idea, both an end and a means‖. Her study of -the politics of access in the borderlands of Asia‖ draws on the work of the French geographer Jean Gottmann who stated that -one of the major aims of politics is to regulate the conditions of access‖. Opposing the route is what Mahnaz Ispahani calls the antiroute: -any natural or artifical constraint on access‖, ranging from mountains and deserts to -legal boundaries and tariffs that raise the cost of crossing them‖. Antiroutes, as she rightly observes, -may serve the same human purposes as routes‖, that is, to regulate the conditions of access. Indeed, -what routes move, and what antiroutes prevent from moving, are people and goods within and across frontiers‖ 21 . And routes are consubstantial to borders since -without land routes, borders cannot be defined and secured‖.

Ispahani continues, -Whereas states cannot come into existence without the ability to deny access, they cannot be physically consolidated and politically sustained without the ability to expand access-without the extension of the authority and the legitimacy of the center to the peripheries‖ 22 .

As Lord Curzon, Governor General and Viceroy of India (1899-1905), remarked, -the earliest frontiers ‗erected a barrier or created a gap', that is, restricted movement and access‖ 23 . What was true in the borderlands of Southwest Asia, and for its borderlanders, can also be osberved in the frontier area that stretched between Burma and Siam in the 19 th century. When the British raised the question of the western frontier of Siam, in the early 19 th century, no document or treaty identifying and delimitating the boundary could be provided by the local chiefs, as Thongchai Winichakul explains: -as these were friendly neighbors who shared understanding and trust, one local chief replied, the boundary did not forbid people to trespass or to earn their living in the area‖ [START_REF] Winichakul | Siam Mapped. A History of the Geo-Body of a Nation[END_REF] . The borders were even said to be -golden, silver paths, free for traders‖ and -the tribal people wandering in the mountain forests were subjects of no power‖ 25 . Borders were then far from being boundaries: they were frontiers. Lord Curzon depicted this -widely diffused type of ancient Frontier‖ that was that of -the intermediary or Neutral Zone‖: -This may be described as a Frontier of separation in place of contact, a line whose distinguishing feature is that it possesses breadth as well as length‖ [START_REF]Text of the 1907 Romanes Lecture on the subject of Frontiers by Lord Curzon of Kedleston, Viceroy of India[END_REF] .

Boundaries were surimposed on transfrontier routes then, since Southeast Asian frontiers have long been areas linking policies rather than separating them [START_REF] Chouvy | [END_REF] . Colonialism and, later, nationalism, required having boundary lines clearly demarcated: -The major principle behind the Asian frontier system was recognition of the desirability of avoiding direct contact between the administered territories of the various colonial empires concerned‖ 28 (see map 5). In Asia, where the power over individuals was traditionally separated from the power over land, since a subject was bound first and foremost to his lord rather than to a state, modern boundaries have -violently and arbitrarily‖ divided -ethnic peoples into different nationals‖ 29 .

Hence, the ‗external', or alien, may not really be external -while the ‗internal' can be made alien or external‖ as various tribal or refugee people can still experience in Thailand, where many tribal people have spent decades waiting for Thai citizenship and thus have never -belonged‖ to any state or nation 30 .

As far as the symbiotic relationship between routes and borders is concerned, Abraham and Van Schendel explain how -the act of enforcing a selected flow of people and objects across a border, from border patrols to customs, immediately allows for the possibility of rents to be charged for circumventing these rules and by the same token provides opportunities for smuggling of people and objects across these borders‖. Of course, -The weight of enforcement is directly related to the prices that can be charged for getting around it-the risk, uncertainty and demand for these flows -across the border‖ all go into making the border a site for illicitness, from an economic point of view‖. But, it is also important to understand that -making borders also makes illicit the life activities of border communities‖ [START_REF] Van Schendel | Beyond Borders: (Il)licit Flows of Objects, People, and Ideas‖[END_REF] . Andrew Walker also stresses the fact that -‗open' borders, characterised by flow and passage, usually provide more opportunities for regulation than ‗closed' borders‖ [START_REF] Walker | The Legend of the Golden Boat. Regulation, Trade and Traders in the Borderlands of Laos, Thailand[END_REF] .

Not surprisingly, all kinds of smuggling and trafficking flourish in these old frontier areas that often became buffer zones, as had been and still is the case between Burma and Thailand: if the border not only affords some protection to the refugees (from political oppression, economic distress, or even law enforcement) who cross it, it can also help enrich those who do not travel -empty-handed‖. Thus, a route and an antiroute can engender one another: a closed border can engender a route to transgress it and the rules and restrictions it implies; the presence of a route can call for an artificial antiroute (a checkpoint for example) to monitor or restrict access. Hence the ever-growing diversity of smuggling and trafficking routes and techniques that arise as a consequence of growing markets and increased controls.

From ancient to modern routes

That both legal and illegal goods can be traded on the same routes or even together in the same cargo is made easier by the marked increase in movements of goods by land, sea and even air, especially during recent decades. Hiding illegal goods among legal cargo is becoming easier as the global economy unites national and regional markets and as traded goods become more numerous. But modernity draws heavily on history and so-called new routes are often only old routes that have been rediscovered or revived [START_REF] Chouvy | [END_REF] .

In mainland Southeast Asia, as Mya Maung stresses, history teaches us that most of the trading routes between Burma and Thailand are old historic roads, some of them being -the ancient trails used by the Burmese kings when they invaded Thailand‖ [START_REF] Maung | The Burma Road to Poverty[END_REF] . Mya Maung describes precisely the routes and trading points that allowed black markets to flourish along the Sino-Thai-Indo-Burmese borders: he accounts for -ten different major black market routes between Burma and its three neighbours of China, Thailand, and India‖ 35 .

The most active illegal border trade between Burma and Thailand occurred and still occurs at three points: Mae Sai, Mae Sot and Ranong. Goods traded illegally across the Thai-Burmese border were and are still extremely diverse: according to Mya Maung, it was reported that, in the 1970s, Thailand's major exports through the border outposts were -pharmaceutical products, aluminium, wadding rope-coated fabric, boiler machinery, synthetic rubber, and man-made fibre,‖ while in the 1980s, the dominant exports of Thailand were -edible preparations, organic chemicals, iron and steel, manufacturing articles and wadding rope.‖ The dominant imports of Thailand from Burma have been wood and wood articles, especially teak, and gems‖ 36 .

As for the trade between China and Burma, it developed considerably in the 1990s along the famed Burma Road, across Burma's Shan State toward China's Yunnan Province. Once again, of course, this road and the majority of the Shan trading posts -were not really new, their existence dating back to the days of the Burmese kings‖. In the thirteenth century, -Chinese trading caravans and the invading army of Kublai Khan from China travelled that route‖ 37 . As with Thailand, goods illegally traded between Burma and China are manufactured in one direction and natural products in the other. Another major trading route between Burma and China lies in Kachin State and was, until the Kachin Independence Army lost control over the jade mines, -the main route for smuggling famous Burmese jade and

gems‖ 38 .
These old trading routes of mainland Southeast Asia, some of them also linking China to India, have been plied by merchants even when international boundaries were officially closed. Because clandestine border crossings are illegal, the increased risk of such actions raises the value of both the people and goods that accomplish it: having to deal with closed borders, and as some rarefied goods became more expensive and interesting to trade, merchants turned into smugglers and, or, traffickers. Indeed, as many have acknowledged, -making borders engenders illicitness, or in Janet Roitman's words, transgression is productive‖ [START_REF] Van Schendel | [END_REF] .

The evolution of drug trafficking in the Golden Triangle has forged new transport routes in the region and has brought abandoned routes back into service, such as those previously used by communist guerrillas. Other pathways were never abandoned. Traditional caravaners such as the Haw of Thailand and the Hui (Panthay) of Burma are very active in the regional illicit drug trade, and still use routes today that their forebears used at the end of the 19th century [START_REF] Chouvy | Yaa Baa. Production, Traffic and Consumption of Methamphetamine in Mainland Southeast Asia[END_REF] (see map 7).

It should be noted here that smuggling and trafficking are old activities that are consubstantial to trading and date back to the earliest regulatory practices meant to restrict and tax commerce. Smuggling actually developed considerably in the context of the British and French colonial tariff regimes. In his extremely valuable study of regulation, trade and traders in the borderlands of Laos, Thailand and Burma, Andrew Walker quotes Sidney Legendre, a visitor to Luang Phrabang in the early twentieth century (1936): -The French had placed such a high duty on all goods entering Indo-China that smuggling has become one of the most essential and profitable if not the most honourable of the native trades‖.

Counterfeiting also dates back a long time for Legendre explains that Chinese smugglers -have commenced the importation from China of cheap copies of English, French and American goods‖ and that he himself bought a Waterman fountain pen and a pair of -Keds‖ tennis shoes that he found to be -the rankest imitations‖ 41 . Opium smuggling also preceded opium trafficking: in the context of the British and French colonial monopolies (see map 5), but also of the Siamese monopoly, independent trading was prohibited and opium smuggling became a very profitable enterprise, especially for Yunnanese and Shan caravaners. The British (who sold only Indian opium in their colonial possessions) and the Siamese faced smuggling of Chinese opium into Burma and Siam, while the French faced the same problem in Laos, where they were processing and selling Shan opium from Burma (Kengtung) [START_REF] Walker | [END_REF] .

Diversity and complexity of smuggling and trafficking activities

As we have seen, smuggling and trafficking differ according to the (il)legality of the traded goods. Since the trading activity is basically the same-sending goods illegally across a border-networks and techniques can alternatively or concurrently be used. A great diversity of goods can be legally traded, smuggled and trafficked along one specific route, either separately or concurrently. Trafficking of various illegal goods almost invariably occurs along a single route, in the same cargo or not. This, of course, is not a new phenomenon; for example, drugs-for-arms deals have long been in existence across the world. Obviously, successful smuggling and trafficking routes are very much prone to multiple traffics: in mainland Southeast Asia, as this books shows, most smuggling and trafficking activities appear to occur on the same routes. Overall, the same routes are used for the trafficking in small arms, the trade in illegally logged timber, forest products and wildlife, for people smuggling, drug trafficking, the trade in counterfeit goods and for contraband. The coexistence, both in time and space, of various smuggling and trafficking activities, concurrent or congruent, is frequent as illegal trading, as an activity, is not always segmented according to the goods that are illegally traded.

But while a certain degree of coexistence of trafficking activities exists, some of the activities, such as trafficking in nuclear or radiological materials, are at most only suspected.

On the contrary, activities such as drug trafficking are much better known. Indeed, -although there is little evidence of involvement of organized criminal groups in nuclear trafficking worldwide, the success with which criminals have smuggled other contraband in South and Southeast Asia-such as narcotic drugs and conventional arms-suggests that nuclear trafficking might be carried out with relative ease, along some of the same routes, by the same criminals, with little hindrance by authorities or permeable border controls‖ [START_REF] Prosser | Nuclear Trafficking Routes: Dangerous Trends in Southern Asia[END_REF] . In fact, according to Lyudmila Zaitseva and Kevin Hand, -because of the ease with which organized crime can avoid detection of their illicit activities... [n]etworks trafficking in drugs, weapons, and other illicit commodities are well suited for nuclear smuggling. Their experience in avoiding detection, knowledge of safe routes, protection by corrupt authorities, and established infrastructures can be utilized for trafficking in nuclear and other radioactive material‖ [START_REF] Zaitseva | Nuclear Smuggling Chains‖[END_REF] .

Another well known fact is that arms can be exchanged for illegal drugs by using the same networks and corridors (especially when rebel armies are involved in production, and, or trafficking of drugs), as has been the case in Afghanistan, in Burma and in northeast India.

Human beings, for instance Chinese women, are also smuggled and trafficked into Southeast Asia on the same routes used for drug trafficking to feed, for example, a well-established regional prostitution market (chiefly, Chinese women go south while Burmese heroin goes north). Logically, if drugs can be more or less safely trafficked across certain borders and territories, then other items can also follow the same trails, either hidden into large legal cargo and transited across legal entry points, or more or less discretely smuggled and trafficked over long and porous borders, through mountain passes, across rivers or even by unauthorized or unchecked helicopter flights (antiques from Burma being one example). In mainland Southeast Asia smuggling and trafficking is not only made easier by its often mountainous and heavily forested relief but also by its large number of extremely diverse ethnic groups, many of them tribal and semi-nomadic, who straddle international borders (see maps 2, 3, 6).

The number and diversity of drug trafficking routes enable other types of smuggling and, or, trafficking activities, sometimes by notorious drug traffickers themselves. For example, trafficking in counterfeit goods has recently increased across the Thailand-Burma border.

Based near Thailand's northern border with Burma, some key drug traffickers such as Wei Hsueh Kang have diversified their activities into producing and trafficking pirated pornographic Video Compact Discs (VCDs). This proves interesting since it brings another category of traffickers to the fore: those taking advantage of legal touristic migrations between Tachileck, in Burma, to Mae Sai, in Thailand. The result is an upsurge of trafficking in pirated VCDs. Considering that pirated copies of Hollywood, Thai, Chinese and Taiwanese films can be found everywhere in Tachileck and that -about 1000 tourists cross the border from Thailand to Tachileck every day, rising to 6000 a day during a holiday‖, Thai authorities estimate that about 80% of these tourists buy pirated VCDs in Burma and bring them back in Thailand [START_REF] Post | Drug kingpin moves into porno business‖[END_REF] . Also widely available at Tachileck markets are Chinese-made sex stimulants that are not approved by Thailand's Food and Drug Administration and end up being seized by customs officials from returning tourists. As far as counterfeited goods are concerned, a new trend is emerging in Southeast Asia, where drug-resistant malaria is widespread and is -fuelling a roaring trade in counterfeit drugs, including the new and effective Artemisinin-based Combination Therapy (ACT) drugs‖: -Even the Artemisinin compounds-touted as the solution to drug resistance-are being faked in Southeast Asia.

The counterfeiters follow where people are buying these drugs, counterfeit the drug and put it in the market‖ [START_REF]Drug resistant malaria haunts Southeast Asia, fuels illicit trade‖[END_REF] . This is a clear and recent example of how drug-trafficking routes can be used for other trafficking activities. In this case, a famous drug trafficker diversifies its production and trafficking activities thanks to the networks and routes he controls. But such routes are being widely used by other smugglers and traffickers, either for the same trades or for different ones.

The scope of illegal trades in Mainland Southeast Asia

Various examples of smuggling and trafficking activities show that these drug trafficking routes are conducive to multiple trafficking. Mainland Southeast Asia has experienced decades of wars and conflicts, from the Indochina wars, including the Vietnam War, to the internal conflicts in Burma and Cambodia. The armed violence and numerous human rights violations of the Rangoon junta and its army in Shan State, for example, have increased an already constant inflow of Burmese refugees into Thailand. During the past four decades Thailand has become a major country of asylum, receiving some 1.3 million refugees 47 .

Yet, armed conflicts have not only thrown waves of refugees on the roads and across international borders, they have also spurred an international and regional trade in small arms that is still very active and regionally integrated. In the 1990s Cambodia had emerged as a regional market for small arms: -Myanmar rebel groups, secessionists from Sri Lanka and supporters of Acehnese independence movements in Indonesia were among those groups that have were buying weapons from Cambodia's well-established black market‖ [START_REF]Jane's Sentinel Security Assessment, -Cambodia‖, Southeast Asia, Issue Twelve[END_REF] .

Arms shipments from Cambodia could reach all the way to India, as was allegedly the case in the late 1990s when arms consignments comprising -AK series rifles, mortars, landmines, Sten guns and high-powered explosives‖, meant for various insurgent groups in northeastern India, were said to be coming from Bangladesh, where illegal drugs from Burma and arms from Cambodia crossed their paths: -The drug shipments head towards Jaffna and from there to various destinations in West Asia for entry into the European and US markets.

According to intelligence sources, Ranong Island off the coast of Thailand is the staging point for arms shipments that originate from Cambodia and take the sea route through the Andaman Sea to the major receiving point at Cox's Bazar, Bangladesh's southernmost tip‖.

While this route has been used by arms dealers and their end-users for a number of years, the alleged -drug trafficking by the LTTE has added a new dimension‖ [START_REF]Outlook India, -Arms, Drugs, and the Man‖[END_REF] . This maritime route has also clearly been used for trafficking drugs as the January 2001 seizure of heroin and methamphetamine off Surin Island (Thailand) has shown: via the Irrawaddy River Burmese heroin reached the Andaman Sea where fishing boats took it to Ko Surin and unloaded it south of Ranong (see maps 12, 15). Ranong is thus not only one of the main trading points for the Burmese black market; it is also a drug-trafficking node and a well-known passage for human smuggling, as testified by its rampant prostitution. But India's eastern borders with Bangladesh and Burma have also -witnessed smuggling incidents-some of which involved nuclear material of indigenous South and Southeast Asian origin-which since the late 1990s have led authorities to suspect the operation of organized nuclear smuggling rings in the India-Bangladesh border area‖ [START_REF] Prosser | [END_REF] . Indeed, -cesium- Southeast Asian borders are also known for other thriving smuggling and trafficking activities. Burmese teak (Tectona grandis), for example, has long been increasingly logged and exported to Thailand, some of it smuggled, since in 1989 Thailand forbade its own teak from being cut. Farther north, on the Chinese-Burmese border, it is the Wa hills that are being deforested, this for the economic benefit of China and in the context of a hastened opium suppression programme [START_REF] Chouvy | The dangers of opium eradication in Asia‖[END_REF] . Much has been said on Burma's balance of payments and the fact that it shows hundreds of millions of dollars in unexplained foreign financial inflows. The most widely accepted explanation was that heroin exports were the largest contributor to the country's economy. However, illegal timber exports are likely to have contributed tens of millions of dollars to these financial inflows. -As well as deliberately concealed exports, another explanation for the export-import discrepancies … is that substantial timber exports are taking place from territories outside the control of the Forest Department. Both explanations are probably valid. Burma's biggest customers (China, India, and Thailand) are not only its neighbours, thus facilitating unofficial cross-border trade, but also report the greatest differences between their imports and Burma's declared exports. Thailand reported more than four times Burma's declared exports in 1994 and double the declared exports in 1995; India did not provide any statistics for 1994, but in 1995 its declared imports were 30 times greater than Burma's declared exports. Burma reported no exports to China in 1995, though China declared imports of more than 500,000 m 3 ‖ 53 .

According to the Chiang Mai based Lahu National Development Organisation, -There is hardly any teak forest remaining [in Eastern Shan state, Burma], but other kinds of hardwood, pinewood and fragrant sandalwood are still in great demand‖. The LNDO also reports that -[m]ost of the ceasefire groups and militia are involved in logging in their areas, some in conjunction with wealthy businessmen from the cities‖ and that -[t]he UWSA's Hong Pang company is currently the main organisation in eastern Shan State carrying out logging. They have their own logging equipment, and also sub-contract other local or foreign (Thai or Chinese) loggers with equipment to carry out the logging‖ [START_REF]Aftershocks along Burma's Mekong[END_REF] . More of Burma's natural resources are being plundered in the country's peripheries as numerous non-timber forest products are also being removed from Burma's luxurious forests. The LNDO also mentions that: -There is a huge demand from China for wildlife and forest products, mainly for medicinal purposes. These include tortoises, bears' gall bladders, snakes, otter skins, pangolin scales and wild orchids. Despite the fact that many of these species are endangered and trade in them is prohibited in Burma, there exists a thriving black market network to locate and export the various items. The main dealers are Chinese businesspeople living in towns such as Tachilek and Kengtung. They send out representatives to villages, where they place orders for certain products with local agents. Villagers are told that if they can find the products, they will receive a particular amount of money, for example up to 20,000 kyat (approx US$20) per 10 tical (approx 160 g) of bear's gall bladder or 150 000 kyat (approx US$140) per viss (1,6 kg) for first class orchids‖ [START_REF]Aftershocks along Burma's Mekong[END_REF] . The wildlife of mainland Southeast Asia has already considerably suffered from the wide-scale hunting, poaching, and trafficking of numerous species, reorienting the plunder and trade toward countries that have been somehow spared until recently. Hence, -as neighbouring countries have exhausted their own valuable natural resources, the price for Cambodia's last populations of tigers, elephants, and bears has soared to levels undreamed of even a decade ago‖. But Cambodia is not the only country concerned: -as demand for wild animals has grown in far off places, new supply routes have opened up in Asia‖, most notably in Burma, and -the supply routes are growing bigger and more sophisticated by the day‖ [START_REF] Davies | On the Trail of the Wildlife Traffickers‖, The Irrawaddy[END_REF] . As suggested by the above-mentioned examples, smuggling and trafficking activities are widespread and extremely diverse in Southeast Asia.

Trafficking synergies or isolated trends?

There is a distinction that goes beyond that made between smuggling and trafficking. Indeed, smuggling and trafficking vie not only on newly generated resources such as illegal drugs but also and even more on non-renewable natural resources: most of smuggling and trafficking activities thrive on what can be designated as predatory economies and activities, that is, most notably, plundering of natural resources. What is rarely acknowledged is that such trading can prove much more detrimental to the environment and to human societies than the production of, and trafficking in, illegal drugs (the environmental costs of which should not be ignored either) or counterfeit items (even though counterfeit mechanical parts and medical drugs present obvious dangers). But since smuggling and trafficking are of concern for source, transit, and destinations countries, one has to dissociate the impacts and consequences of these trades according to their very nature and extent. For instance, human trafficking can have extremely detrimental social and health consequences in source as well as in destination countries. As for the trade in exotic timber and rare animal species, it can create environmental havoc in source countries (forest depletion but also landslides, vulnerability to tidal waves, etc.) but is unlikely to have dramatic consequences in destination countries, at least until a probable global impact is felt in these countries.

Moreover, some law enforcement activities can have rather perverse and so-called unintended consequences, fuelling other illegal activities than the targeted one as producers and, or, smugglers and traffickers resort to alternative economic activities to make up for lost revenues. For example, the -war on drugs‖ can clearly be counter-productive in terms of drug production, -resulting in perverse incentives for farmers to grow more drugs (e.g., in Colombia), displacement of production to more remote areas, and fuelling of violence and insecurity (Peru, Bolivia, Colombia), which in several cases forced the eradication policy to be reversed and led to adverse political outcomes‖ [START_REF]Afghanistan: State building, sustaining growth, and reducing poverty[END_REF] . No doubt, such a phenomenon occurs in Asia too, where the failure to provide economic alternatives to opium production before eradicating poppy crops also can have a devastating impact on the impoverished rural people who depend on the illegal opium economy for their livelihood [START_REF] Chouvy | The dangers of opium eradication in Asia‖[END_REF] , and thus foster other drugtrafficking activities (heroin in lieu of opium, methamphetamine in lieu of opium and, or heroin) such as human trafficking, widespread logging, trafficking in rare species, etc.

Other such synergies can be suspected and still need to be properly documented and understood. For example, various trades and movements can be linked: the sex trade can, to some extent, be nurtured by ill-designed and ill-implemented anti-drug policies, thus worsening an AIDS pandemic that, in Asia, grows mostly through intravenous drug use. The AIDS pandemic can also be suspected of spurring child prostitution as it is likely that the worldwide explosion of child prostitution that happened after 1985 has been partly driven by the fear of AIDS (but also by a growing worldwide tourism industry that made sex tourism more affordable). Moreover, when eradication of illegal crops such as opium is favoured against the development of alternative livelihoods, -unintended‖ consequences such as accelerated deforestation and other predatory activities are very much likely to occur.

As for small arms smuggling and trafficking, mostly of ordinary conventional weapons, it is responsible for the vast majority of casualties in the world's conflicts and thus for the death, wounding and uprooting of a countless number of people each year 59 . In Southeast Asia, as is now well known, decades of armed conflicts (in Vietnam, Laos, Cambodia, Burma) have spurred the production and traffic of opium, heroin and, more recently, methamphetamine. But armed conflicts have also put hundreds of thousands of refugees on the move and across the national borders of the region, creating favourable conditions for the growth of black markets, the regional sex trade, and drug trafficking and consumption.

Of course, demand from buyers around the world plays a significant role by fuelling these trades. But poverty and underdevelopment as well as economic disruptions, political crises, armed conflicts and natural catastrophes create local, national and regional contexts and synergies that can push people into smuggling and trafficking. In Southeast Asia as in the rest of the world the smuggling and trafficking phenomenon is extremely diverse and complex.

Complex yet unaccounted, for synergies are undoubtedly at work between different smuggling and trafficking activities. The case of mainland Southeast Asia shows a complex reality in which every smuggler or trafficker may not be a versatile and diversified merchant, but where many illegal trades coexist and can compete with and, or, benefit from each other, though to an extent that will not be satisfactorily known and understood until further research is conducted through specific case studies.

Five authors, six case studies

This volume addresses the diversity and complexity of illegal trading in mainland Southeast Asia, not by presenting an exhaustive state of illegal trades but by surveying the scope and multi-fold nature of the phenomenon. As an atlas, it focuses on the routes used to carry various illegal trades in the region. The attempt here has been to gather contributors who could write about illegal trades from a variety of disciplines and could contribute to the mapping of the smuggling and trafficking routes according to their respective fields of expertise. It seemed logical, if not necessary, to draw maps of the routes described in the chapters of this volume, so that the readers could better visualise how illegal trades organised themselves spatially, but also to enable a comparison between the different routes followed by the different trades. In the end it appears that the different trades tend to follow the same routes, with the same main cross border points being used for either drug trafficking, human smuggling or trafficking, the illegal trade in wood, wildlife, small arms, and counterfeit goods (see map31). In fact the smuggling and trafficking routes correspond to a great extent to the main transport corridors of the region (compare maps 8 and 31): basically the historic trading roads of mainland Southeast Asia, India, and China (map 7) that were included in both the Asian Highway Network project (1959) and the more recent Greater Mekong Subregion corridor project (1992) (map 8).

Mapping smuggling and trafficking routes is a difficult and delicate task, not only because such activities are meant to be concealed, but also because of difficulties and limitations inherent to the cartographic process. Mapping is not very different from writing in its way of describing and representing reality, yet it is too often read as being not a representation of reality but the real itself. The map, writes Marco Quaggiotto, -is not only a passive representation of reality but a tool for the production of meaning‖, just like any text: -The map as narration, is thus the expression of a communicative purpose‖ [START_REF] Quaggiotto | Knowledge cartographies: Tools for the social structures of knowledge‖, Changing the Change Conference[END_REF] . But -a representation is reproduced rather than reality‖ stresses Geoff King, who also warns that, too often, in the cartographic process, -the distinction between reality and representation becomes blurred‖ [START_REF] King | Mapping Reality. An Exploration of Cultural Cartographies[END_REF] . Quaggiotto rightly explains:

-Just like a text, the map makes selections on reality, distorts events, classifies and clarifies the world in order to better tell a particular aspect of a territory, an event, a space.

When used with malice, it can hide, conceal, falsify or diminish a reality through the construction of an ideological discourse, in which the communicative aims are hidden to the user. In this context, the term ‗map' is a synonym of visual narration of space: a cultural artefact created by an author to describe a space according to an objective‖ 62 .

In fact, cartography, like any discourse, has its own rhetoric, that is, -a linguistic technique used to select and process elements of reality in order to transform them in an effective speech‖ 63 . This is actually what Van Schendel aims at when he criticizes what he calls a -surfeit of arrows‖. Arrows, bodies and heads, are of course useful tools resorted to by the cartographer while mapping smuggling and trafficking routes, something that Van Schendel denounces not only because -the arrow is a godsend for those wishing to represent illegal flows in a threatening manner‖ but also because:

-The discourse on illegal flows focuses on the (ill) effects of the flows at their points of destination but has little time for possible effects at the various staging posts, including borders: it is the head of the arrow rather than its body that we are invited to concentrate on‖ [START_REF] Van Schendel | Spaces of Engagement‖[END_REF] .

Arrows were of course used in this atlas, not -to represent illegal flows in a threatening manner‖ but because the arrow is a -discursive tool that conveys the notion of motion, stimulus, and target as perhaps no other graphic code could‖ 65 . Also, borders were drawn in a very usual way by using thin lines that can also be said to misrepresent the reality of borderlands and frontiers (something that Van Schendel does not criticize). An effort was made, however, to represent smuggling and trafficking as cross border activities by detailing as many border towns, staging posts, and hubs as possible (Tachileck -Mae Sai and Muse -Ruili for example). In any case, cartography is obviously -an art of compromise and partial solutions‖ 66 and a knowledge map should never be conflated with the reality it intends to depict or represent. Van Schendel is right when he writes that -bold arrows hide more than they reveal‖ as many maps of flows are drawn with broad arrows showing only directions and not actual routes or roads, something that was avoided in this atlas. This is actually why arrows in this atlas are not -quick stopgaps‖ that hide -our lack of detailed knowledge, dramatizing and simplifying processes that we understand at best in outline‖ [START_REF] Van Schendel | [END_REF] . In fact, here, the maps are nothing more, or less, than the graphic equivalent to the texts that they illustrate.

Texts and maps complement one another not only by helping the readers to place the many locales in the region but also by showing the limited extent of our knowledge and of our understanding of what stay, in the end, complex and constantly changing phenomena.

To some extent the maps of this atlas look alike: the main smuggling and trafficking routes are often the same no matter what is actually being smuggled or trafficked. Yet, smuggling and trafficking sometimes occur in opposite directions along the very same routes: for example, drugs and arms often go opposite ways. And wildlife and timber go from Burma to China along the same routes used to introduce counterfeit goods from China to Burma. The reader also needs to keep in mind that smuggling and trafficking can, and most likely do, also occur in the blank spaces on the maps: if anything, blank spaces represent more a lack of hard evidence than an absence of smuggling or trafficking routes. As the English poet William Cowper (1731-1800) wrote, -Absence of proof is not proof of absence‖.

The book is divided in 7 chapters and 30 maps. In chapter 1, I, as a geographer, introduce this volume by stressing how mainland Southeast Asia shows a complex reality in which every smuggler or trafficker may not be a versatile and diversified merchant, but where many illegal trades coexist and can compete with and, or, benefit from each other. In chapter 2, I provide a broad history and geography of the drug trafficking routes in and out of the socalled Golden Triangle, whose opium and heroin production and networks have played a significant role in both the regional and world history. I detail the old and new drug trafficking routes and conclude that -drug trafficking is only one aspect of the drug economy and while the goals of a drug-free world or a drug-free ASEAN will never be reached, efforts can and should be made to minimize the harms caused by illegal drug production, trafficking, and consumption‖. Chapter 3, by anthropologist David Feingold, focuses on human smuggling and trafficking, a highly complex trade that has many historical and social and political causes and implications. Feingold calls for the need to develop an epidemiology of trafficking and warns against -more restrictive border security that will push greater numbers of migrants to depend on traffickers and smugglers to move them across borders‖. In chapter 4, David Capie, a political scientist, examines the illegal trade in small arms, obviously a key topic in mainland Southeast Asia with its many passed and ongoing armed conflicts. As Capie explains, -while there has been impressive rhetoric about the need to tackle the illicit arms trade in the region, there has been much less in the way of practical action‖. He concludes that -there is little evidence that weapons trafficking will disappear from the regional landscape any time soon‖. Chapters 5 and 6, by political scientist Vanda Felbab-Brown, examine two other keyand interrelatedtopics in mainland Southeast Asia: illegal logging and wildlife trafficking. Since illegal logging accounts -for a very large portion of forest destruction in the region‖, Felbab-Brown explains that -law enforcement can be tightened, regulatory regimes improved, demand for certified timber encouraged, and demand for timber overall reduced‖ but that it remains to be seen -whether these measures can be developed and adopted on a sufficient scale to preserve the world's natural biologically-rich forest ecosystems that are collapsing at an unprecedented rate‖. Similarly, she stresses how, -sadly, the overall prospects for designing policy interventions in a way that can achieve substantial reduction in the illegal trade in wildlife in Southeast Asia are not high‖. In Chapter 7, Bertil Lintner, a journalist, surveys the trade in counterfeit goods and in contraband, two prominent activities in mainland Southeast Asia. Lintner estimates that -there is little that can be done to stop the flow of consumer goods-whether real or counterfeit-from China to Southeast and South Asia‖. Some of mainland Southeast Asia's countries rank among the world's most corrupt countries, with Burma being perceived as the third most corrupt country in the world, after Afghanistan and Somalia (in 2009 and according to Transparency International). As for the others, Laos ranked 158, along with Cambodia, while Vietnam ranked 120, and Thailand 84, along with India. China fared a bit better as the world's 79th most corrupt country. On the other end, Singapore ranked as the world's third least corrupt country.

Therefore, Cambodia provides a great case study of how corruption undermines antitrafficking efforts: it is not usually perceived as being as corrupt as Burma but still ranks as one of the most corrupt countries in the world. Cambodian corruption clearly hinders antitrafficking efforts at various levels and stages, including at international borders. This was any of the nine aforementioned cross border checkpoints, except for small quantities years ago. Seizures seemed virtually nonexistent and the Cambodian customs appeared to be mostly concerned with collecting tax and duties while the border police and the immigration police did not seem to be more efficient at intercepting traffickers or smugglers. But corruption is not the only issue hindering anti-trafficking efforts in Cambodia, or in the other countries of the region. In fact, the Border Liaison Offices (BLO) (see map 9) set up by UNODC in Cambodia, if functioning at all, did not seem to be very efficient either. The staff of the Poipet BLO was actually absent (reportedly in Phnom Penh) when visited in late 2010 (although the visit had been planned in accordance with UNODC) and interviews conducted with senior administrative authorities revealed that bilateral meetings or communications rarely happened and never yielded any result. Corruption is obviously a major hindrance to counter-trafficking policies in mainland Southeast Asia but ill-designed programs also bear responsibility for the overall failure of interdiction efforts, especially when development programs aimed at strengthening anti-trafficking measures fail to integrate anti-corruption measures, such as in Cambodia.

In the end it seems that while national governments, ASEAN, UNODC, and NGOs have made and keep making efforts against trafficking and smuggling, no significant achievement will be reached without addressing corruption and its causes. In a similar way, addressing illicit drug production in the region will only be possible by addressing poverty, i.e. the main driver of illegal opium production. Corruption and illegal opium production actually happen to have the same root causes: poverty and the desire for a better life, but also violence (repression, persecution, war, genocide) and environmental degradation. Suppressing smuggling and trafficking altogether in mainland Southeast Asia (or anywhere else for that matter) will never be possible for illegal trading is the necessary corollary of commerce. But reducing the scope of smuggling and trafficking is something that can be achieved if the policies and measures devised to address the problem also aim at the root causes of the phenomenon, that is, poverty and corruption.

  137, a radioactive material that could fuel a potent Radiological Dispersal Device, was smuggled into Bangkok, Thailand, in 2003. The material was reported to have entered Thailand across the Laotian border and was said to have been of Russian origin. In 2001, equipment stolen from a public works facility in Bangkok contained radioactive material, including cesium-137. In addition, [...] in 1993, police in Hanoi, Vietnam, arrested a Vietnamese man for smuggling 10 kg of uranium from his former workplace in the former Soviet Union‖ 51 .

  verified during three field trips undertaken in Cambodia in 2010 and 2011. Nine points of entry into Cambodia were visited, on the coast (the deep water sea port of Sihanoukville and the Oknha Mong Port near Keo Phos) and the borders of Thailand (Poipet, Cham Yeam, Prom), Vietnam (Bavet, Tropieng Phlong, Tropieng Sre), and Laos (Dong Kralor). No matter what material or human means were deployed at these points of entry, almost no seizures of any kind were made during the last years, according to interviewed officials. For example, not one single seizure of illegal goods was made using the container scan of Sihanoukville since China offered it to Cambodia in 2005. Seizures of illegal drugs were almost unknown at


Koenraad Theuwissen

Marie-Christine Lafont

Lydia Laffont

Bernard Viguier

Jacques Lacaze
email: jacques.lacaze@ensiacet.fr

M.-C Lafont

Á L Laffont

Á B Viguier

Á J Lacaze

Microstructural Characterization of Graphite Spheroids in Ductile Iron

Keywords: Solidification, Cast iron, Crystal growth, Graphite, Transmission electron microscopy

The present work brings new insights by transmission electron microscopy allowing disregarding or supporting some of the models proposed for spheroidal growth of graphite in cast irons. Nodules consist of sectors made of graphite plates elongated along a hai direction and stack on each other with their c axis aligned with the radial direction. These plates are the elementary units for spheroidal growth and a calculation supports the idea that new units continuously nucleate at the ledge between sectors.

1 Introduction 60 years ago, the discovery of the spheroidization process of graphite in cast irons was a major breakthrough in materials science and engineering as these alloys then presented a new range of properties and applications. Since then, a significant amount of research has been carried out to determine the growth mechanism of graphite nodules. The present work brings new results allowing disregarding some of the models proposed for this growth while sustaining the bases of others.

Without a spheroidization treatment, growth of graphite in usual cast irons proceeds by rapid extension of the precipitates parallel to the basal plane-i.e. along the hai direction -with frequent bending and branching of the elongated lamellae thus formed. It has been suggested that this growth direction is favoured because of the much higher binding energy between carbon atoms in the basal planes than between graphene layers. On the contrary, graphite spheroids (see Fig. 1) consist of adjacent conical sectors developing radially from the nodule centre, with the graphite c direction parallel to the radius.

It would thus appear that in the case of spheroidal graphite, growth occurs preferentially in the c direction. For some authors, this implied the existence of a mechanism enhancing c axis growth in graphite spheroids at the expense of growth in the hai direction. The presence of screw dislocation spirals in very slowly grown natural graphite [1,2] led Hillert and Lindblom [3] to suggest a model for spheroidal graphite growth based on screw dislocations. In this model, the growth of the cones occurs by addition of atoms at the step ledge of a screw dislocation whose axis is perpendicular to the graphite basal planes. The authors suggested that the elements added for spheroidization (Mg, Ce…) promote screw dislocations by adsorbing onto the graphite lattice. From the observation of graphite grown from the gas phase, Double and Hellawell [4] suggested a very similar model based on cone-helix structures made of curved basal planes. In these structures, the basal planes present rotations around the c axis of graphite at angles corresponding to optimum coincidence configurations between successive graphite layers. Miao et al. [5,6] have adopted a nearly identical model when their observations by transmission electron microscopy (TEM) showed that the sectors contain numerous crystal defects and particularly tilts around the c axis which can not be reconciled with the nearly perfect alignment of the c axis expected after spiral growth.

In opposition to the above models and following earlier proposals, Sadocha and Gruzleski [START_REF] Sadocha | The Metallurgy of Cast Iron[END_REF] suggested that growth of graphite spheroids is circumferential rather than radial. They proposed that multiple twinning can produce curved crystals, i.e. that spheroidal growth could proceed continuously from spheroidal nuclei. It has indeed been observed repeatedly (e.g. by Liu et al. [START_REF] Liu | [END_REF]) that the outer surface of nodules extracted by deep etching sometimes presents extended foliated graphite deposits that give the nodules a cabbage-like shape with leaves partly superposing on each other. However, such a structure where continuously bending graphite foils extend on a significant part of the nodule surface is not representative of the bulk structure and may better be associated to crystallization of amorphous vapour graphite deposits [9] or to solid-state graphite growth in cast iron [START_REF] Purdy | The Physical Metallurgy of Cast Irons[END_REF] or steel [11]. In these latter cases, no subgrain boundaries could be observed in clear conflict with the TEM observations mentioned above [5,6].

Multiple twinning to explain spheroidal graphite growth has in fact been proposed for long time by Shubnikov (referenced by Minkoff [START_REF] Minkoff | The Solidification of metals[END_REF]). Double and Hellawell [START_REF] Double | [END_REF][START_REF] Double | The Metallurgy of Cast Iron[END_REF] considered it as a possible mechanism to generate an imperfect sphere with ill fitting junctions offering numerous sources for layer growth. Detailed studies of multiple branching have been performed by Faivre and coworkers [START_REF] Ryschenkow | [END_REF]16] in the case of pure hexagonal selenium, and Faivre [START_REF] Faivre | Physical Metallurgy of Cast Iron V[END_REF] discussed the parallel with spheroidal graphite growth. In the model proposed by these latter authors, a few plates elongate radially from the centre along their hai direction and branch laterally to fill the space between them. Multiple branching then leads to a structure in which a large proportion of the plates have their c direction parallel to the radius of the precipitate. Such a model seems suitable for explaining the initial formation of spheroidal precipitates but could not be extended to late growth of spheroidal graphite as no part of the bulk of spheroids has been reported with the hai direction parallel to the radius.

The present study is one of the very few papers reporting TEM results to characterize spheroidal graphite in cast irons. It was intended to give clue for selecting a model appropriate for describing spheroidal growth, or at least for excluding those unable to do that. Attempt was thus made to characterize the graphite structure along the radial direction of the nodules.

Experimental Details

The spheroidal graphite cast iron investigated is a standard ferritic alloy used in previous work [18], containing mainly 3.64 wt % C and 2.05 wt % Si. It was spheroidized with a FeSiMg commercial master alloy. The graphite precipitates were of high nodularity, their surface density was evaluated at 400 mm -2 and their mean diameter at 19 lm. Sections of the iron of 1 cm 2 were mechanically ground and polished until 80-100 lm, then sections of 3 mm in diameter were stamped, dimpled and thinned by ion-milling to transparency with a low-angle (0-10°) precision ion-beam polishing system (PIPS) to be observed by TEM. Imaging was performed using a JEOL JEM 2010 electron microscope at the Temscan service of the Paul Sabatier University in Toulouse. The TEM apparatus was operated at 200 kV and the diffraction patterns were carried out by selected area diffraction.

It was difficult to find spheroids with appropriate thickness, most of them being electron transparent only at their periphery, or consumed during sample preparation. Further, it is worth stressing that after extensive TEM examination of a given area, amorphisation of the graphite could be noticed. Whilst this radiation damage is known for other carbon materials [19], it has seldom been mentioned in TEM studies of graphite in cast irons. Care was thus taken for minimizing the time during which the beam was focused on the observed areas, particularly when electronic diffraction had to be carried out.

Results

The photomontage in Fig. 2 shows a graphite nodule whose radius is about 10 lm. Within this nodule, dark areas are metallic particles containing Fe and Si as often observed [20]. The boundary between two sectors can be seen by the change in orientation of the contrast lines, e.g. at the lower right of the photomontage. At the outer limit of the nodules, the sectors appear to be 2-3 lm wide. At a higher magnification, such as in the insert at the upper right of Fig. 2, it is seen that the boundary between adjacent sectors is delineated by the change in the general orientation of the graphite plates stacked on one another in each of the sectors. A few measurements of the angle between the [0001] directions of adjacent sectors were performed as illustrated with the selected area diffraction pattern shown in Fig. 2. Values of 10-15°,2 0 °-22°and 29°-30°have been observed. These high misorientation angles most probably correspond to twins [START_REF] Bollmann | The Metallurgy of Cast Iron[END_REF] and even higher values at 39°-53°are possible and have been reported [5].

As illustrated in the insert image in Fig. 2, it was generally easy to evidence the stacking of elementary graphite plates at the junction of two sectors. Following research on graphene [START_REF] Oberlin | [END_REF], it is suggested to call these individual plates structural base units (SBU). In the present observations, it was found they have a thickness between 10 and 100 nm, values which are similar to those reported by Miao et al. [5] at 120 nm and Monchoux et al. [20] at 100-1,000 nm for spheroidal graphite, but also by Double and Hellawell [START_REF] Double | [END_REF] at 100 nm for lamellar graphite.

In some instances, it was observed that graphite presented microcrystalline areas at the extreme outer periphery of the nodules, over a thickness of about 1 lm. Such an observation has already been reported by Monchoux et al. [20] who related it to solid state precipitation of graphite upon the nodules formed during solidification. As in the case of the extended leaves mentioned above, this feature appears to be peculiar and focus was put later on bulk graphite.

It was thus intended to map the crystallographic orientation of graphite along nodule radii within selected sectors. Figure 3 illustrates one example where this could be achieved over a length of 2 microns. Some areas showed misorientations between each other which could be determined by measuring the angle between their respective (0002) spots in the diffraction patterns (Fig. 3). These misorientations are quite high at 10-11°but still agree with values reported by Miao et al. [5] and Monchoux et al. [20]. Observations on other sectors showed misorientations ranging from 6°to 12°, with a peak at 10°. However, in quite many locations, no misorientation could be observed such as the area between diffraction patterns 2 and 3 in Fig. 3. In such locations, fringes which are due to multiple reflections associated with the local high crystalline quality of the graphite could be seen in the bright field image (arrow). While the observation of areas without misorientation would be in favour of the helix-like models, the presence of faults within the same sectors leads to definitely disregard them.

The centre of the spheroids was often too thick for TEM observations. However, a partially torn spheroid shown in Fig. 4 enabled some investigation of the core. The upper part of the figure shows the irregular edges of the hole made by ion milling while the lower right corner (dark contrast) corresponds to the matrix. Several selected area diffraction patterns recorded near the core with a 250 nm diameter aperture revealed a structure made of small areas with different orientations. The diffraction pattern shown in the figure was taken in this same zone with a 1 lm diameter aperture to illustrate the resulting microcrystalline structure at the centre of the spheroid.

Discussion

It can be considered that graphite in spheroidal graphite cast irons is made of SBU which consist of graphene layers of nanometric size piled up without any crystallographic defect [START_REF] Oberlin | [END_REF]. In the centre of the nodules, the arrangement of these SBU gives a diffraction pattern that appears polycrystalline and could well be in agreement with the multiple branching model described for growth of spheroids in selenium [START_REF] Ryschenkow | [END_REF][16][START_REF] Faivre | Physical Metallurgy of Cast Iron V[END_REF]. After the core has formed, further growth of the graphite spheroids proceeds with the development of sectors where the SBU stack on each other with the graphite c axis roughly parallel to the radius of nodule. Within the sectors, the SBU can be perfectly stacked over a certain length but will eventually present faults and tilt misorientations between each other. As already stressed, the presence of these faults leads to disregard the models based on a helix which assumes perfect stacking of graphite layers.

The SBU appear to be elongated along their hai direction, exactly as lamellae in cast irons which have not been treated for spheroidization. This means that the growth rate of graphite remains much more rapid along the hai direction than along the c direction, even during spheroidal growth. One way to connect this observation with the overall growth along the c direction is to assume that new SBU are regularly nucleated at the precipitation front. Following Double and Hellawell [START_REF] Double | [END_REF][START_REF] Double | The Metallurgy of Cast Iron[END_REF]23], the most probable locations for the nucleation events are the ledges formed along the outer junctions of neighbouring sectors. It may be imagined that caps of graphite nucleate along these boundaries in epitaxy with one of the sectors over which they expand. It may be postulated that these caps are cylinders elongated along the ledge with a section that is onefourth of a circle whose radius is the critical radius for nucleation, r c . This radius is given by r c = c/DG, where c is the surface energy and DG is the driving force that may be estimated as DG = L V (1 -T/T eut ), where L V is the latent heat of melting per unit volume and T eut the eutectic temperature. Using the values selected by Johnson and Smartt [24] for c and L V and denoting DT = (T eut -T), one gets r c (nm) = 600/DT. For a typical undercooling DT of 5 K during eutectic solidification, the critical radius is 60 nm, well within the range experimentally observed for the thickness of the SBU. This simple estimate thus gives support to the model suggested by Double and Hellawell [START_REF] Double | [END_REF][START_REF] Double | The Metallurgy of Cast Iron[END_REF]23] for spheroidal growth after the sectors have formed.

Conclusion

The present results lead to disregard any cone-helix model to explain spheroidal growth of graphite in cast irons. Instead, the above views put emphasis on the role of twinning on the formation of the inner part of the nodules as well as on the development of the sectors. However, twinning events should be much more numerous during spheroidal growth than during lamellar growth. It thus seems that the role of O and S which are withdrawn from the melt by the spheroidization treatment is not only to create an avalanche of carbon atoms on the prismatic planes (so as to explain the lamellar growth) but also to limit twinning. In this line of thoughts, the effect of some elements on the primary growth of graphite has been recently investigated with secondary ion mass spectroscopy [18] and further TEM investigations are presently being carried out.

Fig. 1

 1 Fig. 1 Optical micrograph (polarized light) of a graphite spheroid in cast iron showing sectors

Fig. 2

 2 Fig. 2 Bright field TEM photomontage of a graphite nodule. In the insert, bright field image of the boundary between two adjacent sectors and selected area diffraction pattern corresponding to the white open circle in the latter. The angle between the [0001] direction of graphite in the two sectors is a = 31°F

Fig. 4

 4 Fig. 4 Bright field image of a graphite spheroid torn by ion milling and diffraction pattern taken at its centre. The selected area aperture diameter is 1 lm( white open circle in the bright field image)


Claire Cury
email: claire.cury.pro@gmail.com

Joan Alexis Glaunès

Marie Chupin
email: marie.chupin@upmc.fr

Olivier Colliot
email: olivier.colliot@upmc.fr

Fast Template-based Shape Analysis using Diffeomorphic Iterative Centroid

A common approach for the analysis of anatomical variability relies on the estimation of a representative template of the population, followed by the study of this population based on the parameters of the deformations going from the template to the population. The Large Deformation Diffeomorphic Metric Mapping framework is widely used for shape analysis of anatomical structures, but computing a template with such framework is computationally expensive. In this paper we propose a fast approach for templatebased analysis of anatomical variability. The template is estimated using a recently proposed iterative approach which quickly provides a centroid of the population. Statistical analysis is then performed using Kernel-PCA on the initial momenta that define the deformations between the centroid and each subject of the population. This approach is applied to the analysis of hippocampal shape on 80 patients with Alzheimer's Disease and 138 controls from the ADNI database.

Introduction

Computational Anatomy aims at developing tools for the quantitative analysis of variability of anatomical structures, and its variation in healthy and pathological cases [START_REF] Grenander | Computational anatomy: An emerging discipline[END_REF]. A common approach in Computational Anatomy is template-based analysis, where the idea is to compare anatomical objects variations relatively to a common template. These variations are analysed using the ambient space deformations that match each individual structure to c 2014. The copyright of this document resides with its authors. It may be distributed unchanged freely in print or electronic forms.

the template. The Large Deformation Diffeomorphic Metric Mapping (LDDMM) framework [START_REF] Beg | Computing large deformation metric mappings via geodesic flows of diffeomorphisms[END_REF] has been widely used for the study of the geometric variation of human anatomy. This framework generates metrics between deformable shapes and provides smooth and non ambiguous matchings between objects.

Estimating a template from the population in the LDDMM framework, to be used for further template-based statistical analysis, is a computationally expensive task. Several methods have been proposed. Vaillant et al. proposed in 2004 [12] a method based on geodesic shooting which iteratively updates a shape by shooting towards the mean directions. The method proposed by Glaunès and Joshi [START_REF] Glaunès | Template estimation from unlabeled point set data and surfaces for Computational Anatomy[END_REF] starts from the whole population and estimates a template by co-registering all subjects using a backward scheme. A different approach was proposed by Durrleman et al. [START_REF] Durrleman | A forward model to build unbiased atlases from curves and surfaces[END_REF][START_REF] Durrleman | Topology Preserving Atlas Construction from Shape Data without Correspondence Using Sparse Parameters[END_REF]. The method initializes the template with a standard shape, and uses a forward scheme: deformations are defined from the template to the subjects. The method presented by Ma et al. [START_REF] Ma | Bayesian template estimation in computational anatomy[END_REF] uses an hyper template which is an extra fixed shape, and optimizes at the same time deformations from the hyper template to the template and deformations from the template to subjects of the population. All these methods are expensive in terms of computation time, due to the iterations needed for the convergence of the method.

In this paper, we propose a fast approach for template-based shape analysis in the LD-DMM framework. The template is estimated using an iterative approach which quickly provides a centroid of the population [START_REF] Cury | Template Estimation for Large Database: A Diffeomorphic Iterative Centroid Method Using Currents[END_REF]. This method iteratively computes a centroid of the population in the LDDMM framework, which requires only N -1 matching steps, with N the number of subjects, while template estimation methods typically require N such steps per iteration. Using this centroid computation as initialization drastically reduces the computation time for template computation. We use this iterative centroid as a template to study the anatomical variability by analysing the deformations from the centroid to the subjects of the population using Kernel-PCA [START_REF] Schölkopf | Kernel principal component analysis[END_REF]. This approach was applied to 218 hippocampi (80 patients with Alzheimer's Disease, 138 controls) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database1 .

Methods

LDDMM framework

We briefly present the LDDMM framework to introduce notations, for more details see [START_REF] Beg | Computing large deformation metric mappings via geodesic flows of diffeomorphisms[END_REF]. Deformation maps ϕ : R 3 → R 3 are generated via integration of time-dependent vector fields

v(x,t), x ∈ R 3 ,t ∈ [0, 1], such that each v(•,t) belongs to a Reproducing Kernel Hilbert Space V with kernel K V . The transport equation dφ v dt (x,t) = v(φ v (x,t),t) ∀t ∈ [0, 1] φ v (x, 0) = x ∀x ∈ R 3 (1)
has a unique solution, and one sets

ϕ v = φ v (•, 1) the diffeomorphism induced by v(x,t).
In a discrete setting, optimal vector fields v(x,t) are expressed as combinations of spline fields: v(x,t) = ∑ n p=1 K V (x, x p (t))α p (t), where x p (t) = φ v (x p ,t) are the trajectories of control points x p (the vertices of the mesh to be deformed), and α p (t) ∈ R 3 are time-dependent vectors called momentum vectors. Optimal trajectories between shapes can be shown to satisfy geodesic equations for a metric on the set of control points [START_REF] Vaillant | Statistics on diffeomorphisms via tangent space representations[END_REF]. As a result the full deformation between a template shape and its surface target S i is encoded by the vector of initial momentum vectors α i (0) = (α i p (0)) 1≤p≤n i located on the vertices of the template mesh.

Iterative Centroid method

We proposed in 2013 [START_REF] Cury | Template Estimation for Large Database: A Diffeomorphic Iterative Centroid Method Using Currents[END_REF] an Iterative Centroid method which use the LDDMM framework and the framework of currents [START_REF] Vaillant | Surface matching via currents[END_REF]. The authors propose three different schemes for centroid computation, but here we only use the first one, which is the faster one. The Iterated Centroid method consists in applying the following procedure: given a collection of N shapes Si, we first set C1 = S1 (initial centroid) and successively update the centroid by matching it to the next shape and moving it along the geodesic flow. (Algorithm 1).

Data: N surfaces S i

Result: 1 surface C N representing the centroid of the population

C 1 = S 1 ; for i from 1 to N -1 do C i is matched to S i+1 which results in a deformation map φ v i (x,t); Set C i+1 = φ v i (C i , 1 i+1
) which means we transport C i along the geodesic and stop at time t = 1 i+1 ; end Algorithm 1: Iterative Centroid algorithm This algorithm can be defined in a pure Riemannian setting, for the averaging of a set of points p k (instead of shapes S i ) on a Riemannian manifold M. If points p k belong to a vector space and the metric is flat, the algorithm converges towards the mean 1 N ∑ k p k , but in general it depends on the ordering of the points. Back to our shape space framework, we showed in a previous study [START_REF] Cury | Template Estimation for Large Database: A Diffeomorphic Iterative Centroid Method Using Currents[END_REF] that indeed the ordering changes the result, but the different results are very close to each other. Emery and Mokobodzki [START_REF] Emery | Sur le barycentre d'une probabilité dans une variété[END_REF] proposed to define the centroid not as a unique point but as the set C N of points p ∈ M satisfying f (p) ≤ 1 N ∑ N k=1 f (p k ), for any convex function f on M (a convex function f on M being defined by the property that its restriction to all geodesics is convex). This set C N takes into account all centroids obtained by bringing together points p k by all possible means, i.e. recursively by pairs, or by iteratively adding a new point, as we are doing with Algorithm 1. To further reduce the computational load, we used a GPU implementation for the kernel convolutions involved in the matchings.

Statistical Analysis

For the statistical analysis of shapes, we compute a centroid of the population, and we use it as a template. Then we deform the centroid toward each shape of the population to obtain the deformations from the centroid to the population. The deformations are determined by the vector of initial momentum vectors α i (0); we can analyse these deformations with a Kernel-PCA [START_REF] Schölkopf | Kernel principal component analysis[END_REF] as in [START_REF] Vaillant | Statistics on diffeomorphisms via tangent space representations[END_REF]. The Kernel-PCA is the non-linear version of the Principal Component Analysis (PCA) which can be used for learning shape variability from a training set, or for reducing dimensionality of the shape space. In fact the difference between the two versions is in the computation of the covariance matrix, which writes

Cov(i, j) = 1 N-1 (α i (0) -ᾱ(0))K V (x)(α j (0) -ᾱ(0)
), with ᾱ(0) the mean of initial momentum vectors and K V (x) the matrix of the K V (x i , x j ). Then we can run a standard PCA on the covariance matrix Cov.

Experiments and results

Dataset

The method was applied to the analysis of hippocampal shape of 80 patients with Alzheimer's Disease (AD) and 138 controls (CN) (N = 218) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Left hippocampi were segmented with the SACHA software (Chupin et al. [START_REF] Chupin | Automatic segmentation of the hippocampus and the amygdala driven by hybrid constraints: Method and validation[END_REF]) from 3D T1 weighted MRI. Then the meshes were computed using the BrainVisa2 software. They are composed of 800 vertices on average.

Results

We computed a centroid for each of the two populations (AD and CN) using Algorithm 1. The two centroids are denoted IC(AD) and IC(CN). Computation times were 2.4 hours for IC(AD) and 3.6 hours for IC(CN). To assess whether the centroids are close to the center of the respective population, we computed the ratio R =

1 N ∑ N i=1 v 0 (S i ) V 1 N ∑ N i=1 v 0 (S i ) V
between the mean of the norms of initial vector fields from the centroid to the population and the norm of the mean of initial vector fields. Both ratios are 0.25, which means that both centroids are correctly centred even though they are not exactly at the Fréchet mean (which would correspond to R = 0). To visualise differences between IC(CN) and IC(AD), we computed distances between vertices (figure 1) of IC(CN) and the deformation of IC(CN) on IC(AD). We then analysed the variability of the AD and the CN populations using Kernel-PCA. Figure 2 shows, for each group, the principal mode of variation. This figure is obtained by geodesic shooting from each centroid in the first principal direction with a magnitude of ±2σ . One can note that, while the templates of the two groups are different, the variabilities of both groups share similarities. Nevertheless, there seems to be less variability in the medial part of the body for the CN group.

In order to visualize the localization of IC(CN) and IC(AD) and their modes within the whole population, we computed a centroid of the whole population and performed the corresponding K-PCA. We then projected IC(CN) and IC(AD) on the two first principal For each row, the centroid is in the center (in blue), on the right its deformation at +2σ , and at -2σ on the left. The colormap indicates the displacement of each vertex between the corresponding centroid and its deformation. components. We can observe (figure 3) that IC(CN) is on the left of the global centroid, and IC(AD) is on the right, and the 3 principal modes of variation have different directions.

Figure 3: First principal modes of the whole population (in green). In blue, the projections of IC(CN) and projections of its deformations at ±2σ CN in the direction of its first mode of variation. In red, for the AD group. Intermediate points are show the trajectory of the first modes.

Conclusion

In this paper, we proposed a new approach for fast template-based shape analysis in the LDDMM framework. The template is estimated using a diffeomorphic iterative centroid method. The Iterative Centroid is roughly centred within the population of shapes. Analysis of variability is then based on a Kernel-PCA of the initial momenta that define the deformations of the template to each individual. We applied this approach to the analysis of hippocampal shape in AD patients and control subjects. Projection of the templates of the CN group and the AD group onto the main modes of variability of the whole population show that they are located on the main axis of variability. The template estimation takes only a couple of hours for both populations (with about 100 subjects each). The low computational load of the proposed approach makes it applicable to very large datasets.

Figure 1 :

 1 Figure 1: Distances between IC(CN) and IC(AD). On the left, the hippocampus is viewed from below.

Figure 2 :

 2 Figure 2: First mode of deformation of the AD group (top) and of the CN group (bottom).For each row, the centroid is in the center (in blue), on the right its deformation at +2σ , and at -2σ on the left. The colormap indicates the displacement of each vertex between the corresponding centroid and its deformation.

(adni.loni.usc.edu). The Principal Investigator of this initiative is Michael W. Weiner, MD, VA Medical Center and University of California -San Francisco.

http://www.brainvisa.info

Acknowledgments

The research leading to these results has received funding from ANR (project HM-TC, grant number ANR-09-EMER-006, and project KaraMetria, grant number ANR-09-BLAN-0332) and from the program Investissements d´avenir ANR-10-IAIHU-06.