Pr Olivier Nay
email: o.nay@univ-lille2.fr

What drives Reforms in International Organizations? External Pressure and Bureaucratic Entrepreneurs in the UN Response to AIDS

Keywords:

This paper explores organizational dynamics that go with the design and implementation of public administration reforms within the UN system. It focuses on management reforms carried out in the UNAIDS Programme, which brings together ten UN agencies to combat the worldwide HIV/AIDS epidemic. The paper suggests that understanding these reforms requires questioning the exposure of UN administrations to pressures emanating from their environment and, at the same time, investigating the intentions of bureaucratic entrepreneurs who promote and drive reforms within the UN system. The empirical development demonstrates that the swift incorporation of the external pressure into a reform process in the mid-2000s cannot be dissociated from the active support of some UN agencies who have had a common interest in shifting institutional arrangements inside UNAIDS to expand their bureaucratic authority. In conclusion, the paper suggests analyzing reforms within international administrations as social processes driven by both coercion and opportunities.

provides an empirical analysis of the reform of Joint UN Programme on HIV/AIDS -better known as UNAIDS -which brings several UN agencies and a Secretariat together. It focuses on the efforts that have been made to improve the governance of UNAIDS, as well as the various obstacles that may prevent to achieve its objectives. It concentrates on "management reforms," defined as the various intentional actions taken by governing bodies, on one or several occasions, to change the formal rules, procedures and mechanisms of the organizations over which they have authority. These reforms aim at influencing decisionmaking and regulation processes regarding power distribution, resource allocation, human resources, and policy-making 4 . This article explores organizational dynamics that go with the design and implementation of public administration reforms in a UN Programme constituting a multi-organizational system. It pays particular attention to various factors that may explain why public organizations enter into a process of management reform in a certain time and in a specific configuration. It questions the exposure of international bureaucracies to external pressures and, at the same time, investigates the intentions of actors involved in the decision-making processes leading to reform. Therefore it argues that one might not dissociate approaches concentrating on interactions between public organizations and their environment on the one hand, and analytical accounts that focus on administrations and their sub-units as collective actors who are concerned with the realization of specific goals on the other hand. This article also suggests that one might examine both institutional pressure and strategic games, considered as intertwined factors that may open the way to reform in international organizations.

The paper is divided into four parts. Part 1 draws some theoretical perspectives on public administration reforms within international organizations. Part 2 explores some intentionbased and institutional factors that explain why management reforms within UNAIDS could not have come from UN agencies themselves, although they have been assigned to drive bureaucratic change towards an integrated Programme. Part 3 analyses the increasing responsiveness of UN agencies to external pressure in the early 2000s, which contributed to place the governance reform on the UNAIDS agenda. Part 4 analyzes transactional games between UNAIDS members, which led to a new configuration of actors who supported the elaboration and the implementation of reform objectives into the UNAIDS Programme.

Administration reforms in international organizations: a conceptual framework

This paper suggests that understanding the management reforms initiated within a UN Programme such as UNAIDS requires investigating both the factors that lead public organizations to adopt new standard rules and operating procedures in order to respond to the pressure coming from their environment, and the factors associated with the intentions and "observer" to several UNAIDS governing boards. For reasons associated with confidentiality obligations, the author does not quote or mention individuals. This confidentiality does not mean that the role of individual actors should be underestimated in bureaucratic processes within UNAIDS. 4 Therefore, this paper does not concentrate on "institutional reforms," which not only relate to decision-making and regulation within organizations, but also look for an extensive, multi-layered reorganization of bureaucratic structures. Both management and institutional reforms are intended to change governance mechanisms, but this is a merely theoretical distinction: empirically, some management reforms may be so extensive as to result in institutional reform.

activities of "public entrepreneurs" who promote and drive reform processes within these bureaucracies 5 .

The three dimensions of international administrations' exposure to external pressure A wide literature on bureaucratic organizations demonstrates that public administrations are not self-referential organizations. Some perspectives pay attention to the processes by which organizations tend to import policy options, administrative solutions, norms, beliefs, and patterns of behavior that are predominant in other organizations, policy sectors, and countries.

Other approaches focus on transversal relations based on cooperation and conflict bringing bureaucratic agents together with political authorities, policy partners, various stakeholders and opinion makers. Such approaches constitute reasonable evidence that bureaucracies have an interest in their own reproduction and, therefore, are keen to respond to external inputs in order to shore up support and consolidate legitimacy. They examine the extent to which bureaucratic organizations depend on and react to external pressure. Not only do they concentrate on processes by which administrative reforms within organizations are shaped or even driven by external demands, they also pay attention to the capacity of bureaucratic organizations to select, reinvent and locally adapt standardized solutions [START_REF] Eymeri-Douzans | NPM-inspired Reforms: A Differentiated Acclimatisation for a Common Repertoire of Legitimisation[END_REF][START_REF] Holzinger | Causes and Conditions of Cross-national Policy Convergence[END_REF][START_REF] Knill | The Europeanisation of National Administrations: Patterns of Institutional Change and Persistence[END_REF], to accommodate their formal structures without changing their internal practices (March and Olsen, 1989;[START_REF] Meyer | Institutionalized Organizations: Formal Structure as Myth and Ceremony[END_REF], or even to resist to external pressure.

The exposure of administrations to external pressure can be associated with legal-institutional, cultural or material variables. Each variable is referring to a certain type of relation of dependency from the administration to its environment: legality, legitimacy, and interest. On the legal-institutional dimension, the dependency is based on legal regulations associated with the formal structure of the bureaucratic system. As international bureaucracies are organizations driven by governing boards composed of member states, they are subject to binding resolutions that are to be implemented through a large range of formal organizational mechanisms and procedures. Such a perspective leads to understand bureaucratic life by investigating the interactions between the administration's units -considered as "agents"and the member states that delegate power to the administration -considered as "principals". By exploring such interactions, the principal/agent approach can provide some valuable insights into a better understanding of the legal-institutional relation of dependency.

The cultural dimension has been extensively explored by neoinstitutionalist studies on organizations. These studies lay the emphasis on the tendency of public organizations to import the norms, beliefs and institutional standards that are prevalent in their environmenta process known as "institutional isomorphism". They argue that organizations are embedded in interorganizational systems and therefore are concerned about their external legitimacy; consequently they are keen to institutionalize routines, rules, patterns of behavior and standard procedures that are well in fashion in their environment and/or supposed to be efficient [START_REF] Powell | The iron Cage Revisited: Institutional Isomorphism and Collective Rationality in Organizational Fields[END_REF]Meyer and Scott 1992;Scott and Christensen 1995). Neoinstitutionalist studies usually focus on symbolic elements that relate to shared representations, ideological frames, and 'policy narratives'. They provide valuable accounts that help to understand how administrative reforms may be shaped by the success of a normative vision (e.g., new public management precepts), by policy ideas disseminated by other actors6 (e.g., scientific knowledge promoted by epistemic communities, or moral ideas supported by advocacy coalitions), and by long-term change in the underlying representations and belief systems (e.g., global norms such as human rights or gender conceptions).

As regards material aspects, administrations are dependent on various resources that are necessary to implement their activities and possibly to expand their influence. At the international level, they are highly reliant on funds provided by donor organizations, particularly in a time when extrabudgetary funding become key resources to supplement regular budgets. Most international organizations are dependant on governmental organizations representing OECD states (aid agencies and ministries), but an increasing number also rely on non-state financial partners from the charities or the private sector, which contribute to the financing of international programmes in many policy areas. The material dependency does not only refer to financial needs of administrations, but also to technical support and seconded staff provided by various state and non-state actors, which are key partners for international organization as they implement policies.

Empirically, the exposure of public organizations to their environment leads to a wide variety of bureaucratic situations and may yield divergent organizational responses. Firstly, there are different types of external pressure on public organizations. The pressure from the environment may result from direct claims and demands from a wide range of actors (e.g., political authorities, policy partners, rival organizations, interest groups, activist networks). It may result from indirect incentives that are carried by policy broker and knowledge organizations (e.g., groups of experts, think tanks, epistemic communities, consulting firms). In such situations, it may be identified through specific interactions between bureaucrats and actors who work in contact with the administration. By contrast, the pressure may be the effect of a diffuse influence coming from cultural norms and representations, and may lead to incremental and elusive change in the organization. Secondly, the degree of exposure varies from organization to organization, depending on various factors, such as the strength of the bureaucratic culture within the organization, the legitimacy of the administration due to past activities, the capacity of administrative units to build sustainable linkages with policy partners (e.g. interest groups, NGOs, the medias), the financial capacity of the organization, the control of expert knowledge, or the characteristics of the policy sector within which the organization is involved (e.g. organizations acting in technical sectors, such as housing or transport, are usually less exposed than organizations in highly politicized areas, such as migrations). Thirdly, depending on such factors, the external pressure on bureaucracies may lead to a wide spectrum of organizational and policy responses, from institutional compliance to autonomous activities (Barnett and Finnemore 2004). For instance, in a study on the European Commission, C. Boswell (2008), identifies four ideal-typical responses from public administrations to signals coming from their environment: full adaptation, reinterpretation, institutional decoupling, and evasion.

Public administration reform and interest

The analysis of the exposure of bureaucracies to their environment may help understand why they embark on a process of reform. It may help demonstrate that reforming policies regarding bureaucratic norms, rules and mechanisms are connected to incentives from other institutional actors, and are reflecting external shifts in the regulatory and normative patterns in the environment. Nevertheless, this article argues that these approaches should be complemented by and articulated to an analysis of the interests, intentions and strategies of actors who contribute to channel external pressure into appropriate functional responses within the organization. In this perspective, an analysis of reforms within international organizations should also capitalize on studies that focus on the various actors who compose the bureaucratic system itself. Such studies usually consider each administration as a system of actors driven by interests and goals, consolidated by shared norms and beliefs, rather than a single, homogenous organization. They show that social activities within bureaucracies may sometimes lead to organizational change. Most of the time, these studies focus on the interplay between specific sub-units within organizations7 , which contribute to the adaptation of rules and the setting up of new policy-oriented instruments. They draw attention to the individuals, groups and units that drive change, or resistance to change. They may highlight internal competition for power, resource, and prestige [START_REF] Pfeffer | Organizational Design[END_REF], principal/agent relations [START_REF] Vaubel | Principal-agent problems in international organizations[END_REF][START_REF] Vaubel | Staff Growth in International Organizations: A Principal-Agent Problem? An Empirical Analysis[END_REF], policy entrepreneurs [START_REF] Mccown | Policy Entrepreneurs and Policy Change: Strategies beyond Agenda Setting[END_REF][START_REF] Roberts | Policy Entrepreneurs: Their Activity Structure and Function in the Policy Process[END_REF]Weissert 1991), leadership (Baumann and[START_REF] Vaubel | Staff Growth in International Organizations: A Principal-Agent Problem? An Empirical Analysis[END_REF], the activity of veto players [START_REF] Tsebelis | The history of Conditional Agenda-Setting in European Institutions[END_REF], and even the role of bureaucratic culture and professional socialization in the shaping of staff behavior (Cini 1996).

Choosing one perspective and excluding the other would mean maintaining a "blind spot" in the explanation. As Bauer and Knill (2007, 20) argue, analyzing management reforms within public organizations calls for an investigation of the interrelations between external and internal factors. On the one hand, decisions leading to bureaucratic reforms depend to a large extent on transversal activities that connect administrations to the various actors, policy networks and institutions in their environment. They are often imposed or encouraged, and sometimes immediately affected, by signals, direct incentives and structural transformations in the global environment. On the other hand, such reforms also result from the intentions and strategies of units or groups who participate in decision-making within organizations. They may even influence partners' behavior and policy rules in the immediate environment of the organization.

This article tackle a primary question regarding reform activities within UNAIDS: why has the Programme experienced a shift in management rules in [2005][2006], through the introduction of new standards procedures regarding budgets and finance, policy development, and coordination. This paper argues that the choice of UNAIDS members to embark on an extensive reform process is both a response to incentives coming from their environment, and the result of entrepreneurial strategies for change. At the empirical level, it suggests that UNAIDS reforms cannot be dissociated from structural change in global AIDS governance, from coercive pressures emanating from influent actors operating in the environment of the UN bureaucracy, and from strategies carried out by some segments of the UN Programme.

Impediments to cooperation in a fragmented inter-organizational system

While being originally conceived as a "groundbreaking" system aiming at experimenting innovative management and interagency coordination within the UN system, UNAIDS revealed very low capacity to insufflate change in the management and policy-making of the multilateral response to the epidemic until the mid-2000s. This part identify some factors that may explain the impediments to change in the UNAIDS Programme.

The experimentation of interagency coordination in the UN system

When created in 1994 by the UN Economic and Social Council (ECOSOC), UNAIDS was conceived an innovative institutional mechanism aiming at strengthening the commitment of UN organizations to respond to HIV and AIDS, one of the most critical challenges for development. The Programme brings together the efforts and resources of ten UN organizations involved in the response to the epidemic 8 : the Office of the UN High Commissioner for Refugees (UNHCR), the UN Children's Fund (UNICEF), the World Food Programme (WFP), the UN Development Programme (UNDP), the UN Population Fund (UNFPA), the UN Office on Drugs and Crime (UNODC), the International Labour Organization (ILO); the UN Educational, Scientific and Cultural Organization (UNESCO), the World Health Organization (WHO), and the World Bank. These ten international organizations have the status of "Cosponsoring organizations," better known as "Cosponsors." From the outset, UNAIDS was viewed as a cutting-edge system, with the objective to establish new governance mechanisms in the UN system at global level. First, it had been given the task of improving UN governance by strengthening interagency collaboration. Second, UNAIDS was the first UN Programme to introduce the formal representation of civil society on its governing board, with consultative status.

Within UNAIDS the Cosponsors operate under the authority of a governing board 9 . They are assisted by a Secretariat, which is mandated to raise funds targeting HIV/AIDS and to distribute them among the Cosponsors. It also assists the Cosponsors in various ways. Moreover, it is expected to provide strategic information about the epidemic, mobilize technical resources, and engage with governments and civil society. It is to a large extent a "secretariat of UN secretariats".

In 1994, the ECOSOC assigned UNAIDS a very ambitious role in the long run, as the Joint UN Programme was officially established to build global consensus on policy responses to AIDS. Through UNAIDS, governments from the North and South, the UN system, and international partners from civil society were asked to agree on a global framework to combat a scourge that was jeopardizing years of effort in development, especially in sub-Saharan Africa. However, in contrast to other UN programmes whose main objective is to coordinate the efforts of state actors, the creation of UNAIDS was first and foremost a response to internal UN organizational challenges. Through UNAIDS, the Cosponsors were given the mandate of developing a multi-sectoral and integrated response to AIDS, by harmonizing their goals and objectives, constructing common policy tools, sharing knowledge and technical expertise, speaking "with one voice," and, finally, jointly delivering at country level.

8 At the outset, UNAIDS brought together six UN organizations (in fact one member, the World Bank, is a Bretton Woods system organization). In the late 1990s and early 2000s, four new UN entities joined the "UNAIDS family" (ILO, UNODC, WFP, UNHCR). 9 The board is called the Programme Coordinating Board (PCB). It comprises 22 member states, the ten Cosponsors and five organizations representing the civil society. Only member states have the right to vote.

Interagency cooperation was expected to bring about a swift, reactive, and large-scale commitment by the UN to affected countries.

From a broader perspective, as an interorganizational mechanism UNAIDS is expected to ensure the convergence -and, wherever possible, a close match -of policy goals in the areas of HIV prevention, impact mitigation, and access to antiretroviral treatment. It is also mandated to facilitate the elaboration of common management standards and work agreements in the various policy sectors associated with the response to AIDS. A system such as UNAIDS challenges the Cosponsors to combine their activities, even though they are complex organizational systems driven by different mandates, particular policy agendas, specific knowledge and norms, distinct technical expertise, and, last but not least, internal management procedures and routines. It also aims to reduce competition in fund-raising and fragmentation in decision-making, as well as overlap and duplication of effort in the provision of technical assistance to developing countries.

At first sight, the functioning of the UNAIDS system provides a noteworthy example of the restructuring efforts that have been tried out to better coordinate the many UN agencies and programmes dedicated to development and poverty alleviation. To a great extent, when it was started in 1996 UNAIDS was a forerunner of the current UN system-wide reform policy. It was the first UN Programme dedicated to building a multi-dimensional response combining the efforts of various agencies.

The resistance of UN bureaucracies to inter-organizational cooperation

Despite being a good example of the institutional reforms the UN system has sought to set in motion in recent years, UNAIDS demonstrated very little progress in interagency cooperation during the first decade of the Programme. The large number of obstacles that impeded progress toward a unified UN response to AIDS offered significant illustrations of the challenges that go with reform activity in the UN system.

UNAIDS faced not only limitations in financial and human capacity, but also discrepancies between Cosponsors' key policy priorities and objectives. In the first years of the Programme, the absence of standard rules and mechanisms for interagency coordination, the low level of funding devoted to AIDS in most agencies' programmes (except for WHO), and even the mistrust between top-level management teams (for example between WHO and the Secretariat), made the partnership less than consistent with the ambitious objectives set in 1996. The policy dialogue between organizations led to cautious resolutions, most of which could hardly satisfy civil society organizations and networks of people living with HIV and AIDS, whose expectations of UNAIDS were very high at the start of the Programme.

In the late nineties, there was very little chance that a change in UNAIDS governance would be initiated by the Cosponsors themselves. As an inter-organizational system, UNAIDS remained fragmented and poorly managed, as very low resources were dedicated to establish technical partnerships among Cosponsors and to build joint policy-guidance on AIDS. One common criticism, often raised by organizations representing the civil society, asserted that the low progress was resulting from three major factors: a lack of interest from the governments of the North, a political denial and/or a lack of political leadership in countries of the South, and a lack of commitment of international organizations due to their inefficient internal procedures. Connecting the lack of action to a lack of will, this criticism focuses on global actors and their intentions. Nevertheless the following development argues that these three intention-based arguments should be balanced with an analysis of organizational characteristics of UNAIDS, which may explain little progress in reforming institutional practices during the first decade of the Programme.

First, the low integration of the Programme may have resulted from a lack of financial incentives to persuade Cosponsors to effectively engage in interagency partnerships. The donors from OECD countries kept the UNAIDS budget at a level that could not meet the basic requirements for a scaled-up response. In 2002-2003, this budget reached only US$ 190 million, which was far from matching the level of epidemiological threat 10 . Moreover, during the first years of the Joint Programme, the absence of "interagency funds" (funding inducements dedicated to joint activities) meant that collaboration at a technical level was highly unlikely. Although UN policy-makers publicly disapproved of bureaucratic divisions and compartmentalization as a hindrance to a joint response to the epidemic, none of them had an interest in loosing part of their autonomy and influence by being involved in an integrated inter-organizational system, which might increase the risk of cross-checks and mutual surveillance regarding financial expenses, policy objectives, implementation effectiveness, and ethical issues. Each Cosponsor could expect to lose margins of autonomy within a new coordination system.

Second, the lack of authority of the UNAIDS Secretariat is an important factor of poor management and coordination of the Programme in the first decade of exercize. Third, UNAIDS remained a conglomerate of international organizations rather than an integrated system because of inefficient and incomplete institutional mechanisms. Three characteristics of the institutional "architecture" of the Programme highly contributed to protect the autonomy of Cosponsors against pressures from the UNAIDS governing board, and therefore led to a fragmented inter-organizational system. The first characteristic relates to decision-making procedures. These procedures set consensus as a basis for all decisions within the Programme. Not only consensus is the rule for resolutions adopted by the governing board of UNAIDS, but it is also the decision rule within the steering committee bringing the Cosponsors' executive directors together twice a year (the Committee of Cosponsoring Organizations). As AIDS has always been a very controversial policy issue among governments, the consensus-based decision-making mechanisms led to low-profile resolutions of the governing board with few recommendations to harmonize Cosponsors' policy priorities and to set common management tools. The rule of consensus also preserved Cosponsors' executive directors, in their steering committee, to make any decision towards organizational unity that would force other agencies to renounce to their autonomy, especially the most influent ones (such as WHO or the World Bank) that have no direct interest in loosing margins of control by participating in an interagency system. Moreover, despite having been created to ensure a coordination between the Cosponsors before and after each 10 The UNAIDS budget reached US$ 484.8 million for 2008-2009 and is kept flat for 2010-2011 of which US$ 182 million is pledged for the functioning of the Secretariat and US$ 136 million for inter-institutional activities (some of which may be used by the Secretariat). The remaining funds are secured to support activities of the Cosponsors (US$ 161 million) and emergencies (US$ 5 million). 74 percent of the UBW targets country-and regional-level activities, while 26 percent is dedicated to global activities.

governing board, the steering committee acted as a filtering body between the UNAIDS board and the Cosponsors, protecting the UN bureaucracy from direct intrusions from UNAIDS member states.

The second characteristic relates to mechanisms of endorsement involving UNAIDS member states and Cosponsors. The member states adopt resolutions at the UNAIDS governing board. These resolutions are binding decisions, but to be effective they have to be legally endorsed by the governing boards of each Cosponsors so as to be incorporated into their regular programmes. Such a system, requiring a "two-step endorsement" by two distinct governing bodies, reduces the UNAIDS board's authority, which does not have the full resources to compel Cosponsors' top-level managers to systematically connect their AIDS strategies and their micro-management to the rest of the UNAIDS family. It gives too much power to the "gate-keepers" who control the exchanges between UNAIDS and each UN agency. It increases the number of bureaucrats horizontally involved in the decision processes leading to the implementation of each UNAIDS resolution.

A third characteristic of the institutional architecture of UNAIDS has been its low exposure to pressures and controls from the civil society organizations. In the global AIDS governance, civil society organizations have targeted the UN system to prompt governments to engage in massive AIDS responses at national level. They raised strong criticisms against the tendency of UN agencies to develop bureaucratic and scattered responses to AIDS problems. Nevertheless, their representatives have never had much influence on the development of the Programme despite being full members of the UNAIDS board. They take the floor on behalf of the populations who are affected, at risk, or vulnerable. But not only do they not have the right to vote, they do not weigh heavily in the deliberation processes. Moreover, despite interacting on a regular basis with the Secretariat and developing technical partnerships with the Cosponsors on specific policy issues, civil society organizations do not have any permanent forum -except the annual governing board -to ensure collective discussions with all UNAIDS members at the global level.

In this context, one could hardly expect that UNAIDS governance reform would be initiated by its internal bodies, whether they are in the position of principals or agents. The following part argues rather that the management reform of UNAIDS has been resulting from external pressure on the UN Programme. It investigates institutional change in the environment of UNAIDS and the processes by which such change has contributed to make reform a priority on the agenda of all Cosponsors.

The responsiveness of UN institutions to external pressure to reform

This part focuses on two interrelated sets of external factors that have spurred UNAIDS to embark on a process of management reform: the structural change in global AIDS governance, and the pressure emanating from the donors to engage the UN into system-wide reform in a context of diffusion of new public management (NPM) standards.

Global shifts in the AIDS governance and pressure to change

In a globalized world, global AIDS responses illustrate how an international regime has become a pluralistic and complex governance system in less than 15 years. In the early nineties, AIDS policies were initiated by very few UN organizations, with the support of a limited number of donors. Twenty year after, the global AIDS governance is characterized by a complex architecture composed of multilevel institutions and embedded arenas, and involving a whole range of actors with different statuses and roles, such as innovative financial mechanisms, bilateral agencies, financial institutions, foundations, pharmaceutical companies, field-based and international NGOs working in the health and social sectors, activist groups and networks of people living with HIV, community-based and faith-based organizations. These actors represent various constituencies. They are both allies and competitors in public-private partnerships, calling for international funding, building expertise and knowledge, and providing assistance to developing countries and vulnerable populations.

In this polyarchic world, UN actors are no longer spearheading organizations. Most Cosponsors operate as "development partners" in multi-actor policy networks. They still fulfill the mandate to disseminate global policy guidance and provide technical assistance, but they have neither the resources nor the legitimacy to act as leading organizations in their policy sectors. Their individual visibility is lower, especially at country level where bilateral organizations and financial partners are more influential in policy-making mechanisms. Their singularity as drivers of development policies is increasingly challenged by non state actors, which are developing parallel activities in the same policy areas. In some countries, they are likely to be sidelined by host governments who may choose to work with other development partners to build and implement their national AIDS strategy, including bilateral agencies, NGOs, charities and private companies. At the global level, the creation of a multilateral fund disconnected from the UN system in 2001 -the Global fund to fight AIDS, malaria and tuberculosis -constituted a major signal for all UNAIDS partners as the UN system was not considered as an appropriate vehicle to channel multilateral funding sources to countries. In the new governance of AIDS, the UN's leading role can no longer be taken for granted.

These transformations are not specific to the AIDS governance. They characterize most sectors of development. In the new global aid architecture, UN organizations are more exposed to their environment, as well as confronted to a potential decline of their authority in multi-actor networks11 . They have been confronted to permanent criticisms regarding their capacity to deliver technical assistance to countries and populations of the South. UN organizations are therefore particularly concerned with their external legitimacy, as they are challenged to survive by demonstrating their ability to change. They have to give evidence that they have a capacity to change. They are prompted to demonstrate accountability, as well as to adapt their policy objectives and their operating procedures to emerging standards emanating from their environment. UN organizations are challenged to deliver with greater efficiency, through two main directions: the reform of their internal management and the better coordination of the whole UN system. The pressure on the UN system was particularly high in the 2000s, as state representatives from OECD countries drove explicit claims for management reform within multilateral organizations. The following part pays particular attention to the transactional exchanges through which the main donors of UNAIDS addressed the need to disseminate new management solutions within the Programme.

UN system-wide reform, donor pressure and the diffusion of new management standards

The acceleration of UN system-wide reform is a key factor that has stimulated efforts to improve UNAIDS governance. In the early 2000s, a series of high-level meetings on development assistance 12 urged the many UN specialized agencies, funds, and programmes to improve their internal management. These meetings took place in a context of global diffusion of new public management rules and instruments, attesting to the globalization of the neoliberal paradigm already in place in the early 1990s (Common 1998;Suleiman and Waterbury 1990). They resulted in the adoption of resolutions enjoining international organizations to pool resources, undertake joint programming, build knowledge networks, coordinate the provision of technical support, simplify legal procedures, evaluate their results on a regular basis, and align their programmes with government development plans. The pressures for organizational restructuring became very high during Kofi Annan's tenure as UN Secretary-General. In 1997 and again in 2002, the Secretariat General launched a vast series of administration reforms that assigned UN agencies considerable obligations to reform their management rules and standard procedures, and to connect and combine their activities. The commitment to reform has been so high on the agenda of the Secretariat General and various UN bodies that it gives substance to the idea that "reforming the organization" has become not only an objective of the UN but a modus operandi that structures all its activities at every stage.

The call for UN system-wide reform created a momentum that immediately affected UN activities on AIDS in the early-2000s. The pressure to reform the UN system increased with various political commitments that raised expectations among donors and partners of the UN, and created the conditions for reforming the management of UNAIDS13 . These commitments were followed by an independent five-year evaluation of UNAIDS ( 2002), a Consultation meeting on harmonization of AIDS international funding (2004), as well as a 2005 survey on UNAIDS conducted by a network of 16 donors (MOPAN), which fueled criticisms regarding the weaknesses of the Joint UN Programme and the lack of accountability of the Cosponsors. They also revealed how little progress had been made by UNAIDS since its creation in 1996.

As in many other fields of development, they addressed the major flaws, obstacles, and other impediments to an integrated and efficient Programme: lack of responsiveness in the provision of technical assistance in the field; policy gaps; fragmentation of programmes; inefficient interagency coordination; duplication of efforts; and competition among agencies in fund raising and in country-level implementation. Moreover, it was observed that separate UN agendas, lack of joint mechanisms, and actions in parallel, resulted in burdening the national administrations of developing countries. In this context, the key donors of UNAIDS placed the Programme under scrutiny.

The convergence of criticisms regarding UNAIDS revealed contradictory strategies from donor states: the US government found a justification to give priority to its major bilateral initiative against AIDS (the PEPFAR initiative); the French government could justify pushing the Global Fund as an innovative mechanism, as well as a state-controlled programme such as UNITAID, rather than UNAIDS; by contrast, the UK, Scandinavian countries, the Netherlands and Germany found a way to call for a more efficient UN mechanism that would be effectively accountable to their coming financial contributions. Despite promoting different strategies, all bilateral donors had interest in pushing the UNAIDS reform.

In this context, the British government hosted in 2005 a high-level Global Task Team (known as the "GTT") to promote noticeable and swift improvements in AIDS coordination among multilateral institutions and international donors. Convened just one week after the adoption of the 2005 Paris Declaration on Aid Effectiveness, the GTT made recommendations for improving the institutional architecture of the response to AIDS. It urged the Cosponsors and the Secretariat to move towards a comprehensive response demonstrating their capacity to coordinate their many AIDS plans through the Joint Programme. It called for a reform of their management rules with tangible results that could be assessed and measured. The UN General Assembly subsequently endorsed its recommendations during the 2005 World Summit.

The external pressure to reform UNAIDS created the conditions of reform. Nevertheless they would not have come through without the active support of bureaucratic actors within the UN system. As major researches on administration reforms at national level show, the political decisions are not sufficient to explain why administration reforms are engaged. Various groups of actors based within the bureaucratic system (e.g. administrative units, high-level bureaucrats, professions, unions) or situated in the near environment of bureaucracies (policy partners, experts and consultants, pressure groups) may weigh on the reform process [START_REF] James | The Executive Agency Revolution in Whitehall: Public Interest Versus Bureau-Shaping Perspectives[END_REF]Bezes 2009). They constitute a conglomerate of distinct rationalities and interests. They follow specific logic of action and may build individual or collective strategies regarding the reform. They also act according to their own culture, their knowledge and their institutional routines. Their intervention may result in accelerating, reinterpreting or impeding organizational reforms.

Rather than considering the adaptation of the UN Programme to external pressure as a mechanical and diffuse process, the following development pays attention to transactional games bringing together some actors who have been drivers for reform. It focuses particularly on bureaucratic actors who participated in channeling the external demands within the UNAIDS system and were keen to promote organizational reform to strengthen their authority within the UN administration.

Bureaucratic entrepreneurs and management reforms

This section identifies the major steps through which the UNAIDS system has engaged in efforts to set up performance-based management instruments, to harmonize policy priorities, and to strengthen interorganizational coordination. It argues that the active support of some UN agencies who have a common interest in shifting institutional arrangements inside the UNAIDS system may explain the swift incorporation of the donors' demands within a reform process. It draws particular attention to the increasing capacity of the UNAIDS Secretariat to take part in the design and implementation of new management standards and coordination rules within the Programme.

Bureaucratic alliances and the rise of a new configuration of actors

A focus on organizational interests within the UNAIDS system may help understand why some of the Cosponsors may have supported strategies of managerial change. From the early years, as a coordinating body in charge of overcoming organizational compartmentalization within UNAIDS, the Secretariat has always been a supporter of policy convergence, interagency coordination and standardization of rules. Nevertheless, it remained confined in a restricted role during the first decade of the Programme. Its low bureaucratic authority resulting from its position of secretariat, from a lack of support from member states and from a lack of expert capacities, did not provide any chance for the Secretariat to drive Cosponsors towards a more integrated system. For years, Cosponsors' executive directors considered the Secretariat's executive director as a facilitator, rather than a counterpart.

The capacity of the Secretariat to channel the donors' claims for managerial reforms increased in the mid-2000s, as divisions between Cosponsors became higher. The Secretariat took advantage of the divisions between UN agencies to play a greater role in the Programme. It used the temporary support provided by some Cosponsors to overcome the resistance of other

Cosponsors to move towards a coordinated system. Between 1999 and 2004, four new members joined the Programme (UNODC, ILO, WFP, UNHCR), in addition to the six "founding" Cosponsors (UNICEF, UNDP, UNFPA, UNESCO, WHO, World Bank). This new institutional configuration appeared to be favorable to the Secretariat's influence within the Programme. One reason is the greater dependency of the four newcomers on the facilitation role of the Secretariat, which could help them to capture "backstage information", informal rules and bureaucratic routines of UNAIDS, with a greater chance to challenge the influence of the founding Cosponsors. Another reason is the early support of these newcomers to the introduction of new management standards that could change the criteria of resource allocation on their advantage. In particular, the introduction of performance-based standards was an unparalleled opportunity for newcomers to challenge the existing institutional rules based on low mutual control and unclear fund-sharing principles. Such a shift was also supported by three founding Cosponsors (UNDP, UNFPA, UNICEF), mainly because of their institutional commitment to a wider interagency mechanism, the UN Development Group (UNDG), aiming at designing guidance on UN reform at country-level14 . None of these agencies could have found itself in a schizophrenic situation by challenging a shift towards new management rules in UNAIDS while they were supporting similar reform through UNDG.

In this new institutional configuration of the mid-2000s, the capacity of the Secretariat to build cooperative games with the Cosponsors whose rationality and interests were open to a change in the governance of UNAIDS constituted a major step in its ability to instill reform proposals within the Programme. The commitment of WFP was particularly high, as it contributed, together with the Secretariat, to raise pressure on all UNAIDS members in 2005 by convincing the steering committee of Cosponsors to command an "external consultant review" to the Boston Consulting Group (BCG). The BCG, one of the most prominent global management consulting firm, thus played a role in the dissemination of new ideas and norms throughout the Programme, by calling for a greater clarification of Cosponsors' roles and a better accountability system. At the same time, following its mandate in resource mobilization, the Secretariat led bilateral consultations with national delegations and governmental agencies representing the "likeminded donors" of UNAIDS. As these consultations were occasions for donors from Nordic countries and the UK to set conditions in favor of reforming the Programme in the context of the GTT resolution, they gave to the Secretariat an additional legitimacy vis-à-vis the Cosponsors to push efforts towards new management standards within UNAIDS. They also gave the Secretariat a capacity to make a good case for demonstrating its key role in resource mobilization, at a time when some donors of UNAIDS were reorientating their funding strategies outside the UN system.

In the mid-2000s, the balance of power among UNAIDS members imperceptibly shifted from a polyarchic system based on voluntary initiatives of Cosponsors, a certain level of bureaucratic autonomy vis-à-vis member states, and a Secretariat with limited authority, to greater interdependencies among agencies, higher dependency on donors' strategies, and a consolidation of the Secretariat's brokering capacities. With regard to reform incentives, this article argues that such a shift cannot be explained only as the result of the donors' pressure along with UN system-wide reform, but also went with attempts of the Secretariat to build alliances with the new Cosponsors and to embark some of the founding agencies on a strategy of organizational change, while also using its position in resource mobilization to reappropriate donors' claims, and to be given a key role in the design of management reform.

In such a context, some Cosponsors like WHO or the World Bank, which were reluctant to acknowledge the driving role of the Secretariat in the early 2000s, had no longer strong argument to object to strengthened coordination rules. The following development describes the entrepreneurial role of the Secretariat within the Joint Programme, and particularly its contribution to the institutionalization of new policy and management standards in the years 2005-2008.

The UNAIDS Secretariat as a reform entrepreneur

The Secretariat 15 has become a key policy broker in the new institutional configuration that took shape within UNAIDS after 2005, despite a limited mandate and low resources. Not only was it empowered by the principals of UNAIDS to coordinate the setting of reform objectives, it has taken advantage of the lack of cohesion among Cosponsors to gradually broaden its influence as a coordinator of the Programme. It participated in the UNAIDS governance reform in four main areas: dissemination of management standards, policy harmonization, clarification of agencies' policy jurisdictions, and interagency coordination.

First, the GTT recommendations in 2005 constituted a window of opportunity for the Secretariat's executive team to introduce NPM-inspired principles and instruments in the management of the Programme. The first shift took place in 2005 during a closed-door session of a meeting that brought together the UNAIDS "Global coordinators" (Cosponsors' heads of AIDS programmes). The objective was to share out the 2006-2007 UNAIDS budget among the ten Cosponsors. Up until then, the distribution had been based on previous years' decisions, not on a performance review. At this meeting, participants adopted informal criteria to assess the quality and scope of each Cosponsor's AIDS programme, and then voted by secret ballot for a sharing out of the funds. The meeting was an authentic psychodrama. For the first time, UNAIDS funds were allocated according to the mutual assessment of Cosponsors' strategies and results. This new procedure was a first step towards performancebased standards.

The Secretariat's department of Financial Management and Accountability dedicated the next two years to the elaboration of new standards regarding budget and finance. It held several consultation meetings with Cosponsors to come up with measurable policy objectives that could be monitored and assessed through performance indicators and benchmarks. It also contributed to the dissemination of new regulations covering budget management, accounting and contracting procedures, using a results-based management (RBM) approach. In particular, it contributed to the adoption of control procedures aimed at reinforcing the transparency of budget appropriations, to the setting of tracking methods to assess the use of funds, and to the construction the relevant indicators needed to measure the impact of Cosponsors' programmes. In 2007, such a multi-agency results-based budget was unique within the UN system.

Since 2006-2007, the Cosponsors have agreed to shift towards new management standards. Several agencies have been investing in monitoring and evaluation capabilities. They have strengthened oversight mechanisms. They have created procedures to integrate findings into strategic planning cycles. They have set new quantified indicators to make their field offices accountable for policy results on the ground. The objective of this in-depth transformation is to avoid the situation that prevailed during the first decade of UNAIDS: an absence of formal 15 Reform entrepreneurs may be defined as a kind of policy entrepreneur [START_REF] Kingdon | Agendas, Alternatives and Public Policies[END_REF] who promotes innovations in organizational systems (Christensen, Laegreid, Roness and Rovik, 2007;Le Lidec and Bezes 2010). When this paper refers to "the Secretariat" as a reform entrepreneur, it refers to the top and senior managers of this administration (executive head, team leaders, and high-profile technical staff).

rules for the allocation of the UNAIDS budget; a lack of tracking methods, results-based indicators, and independent oversight procedures regarding the use of the funds; and a general trend among the Cosponsors to spend financial resources on scattered and non-coordinated small-scale projects.

Second, the Secretariat also gave major support to policy convergence through the consolidation of a multisectoral policy framework aiming at streamlining the Cosponsors' AIDS strategies under one UNAIDS Programme. At the country level, efforts for UN harmonization were undertaken through a global campaign promoting coordination of national AIDS responses (called the "Three Ones"), as well as through the UN system-wide reform driven by the UN Development Group. At the global level, the Secretariat used the UNAIDS budget as a technical leverage to drive Cosponsors towards an agreement on joint policy objectives. The 2006-2007 UNAIDS budget was the first budget to be built on a resultbased structure. The Secretariat reduced the number of "key results" associated with the Cosponsors' AIDS strategies by 90 %, shifting from 487 in 2004-05 to 46 in 2006-07. In parallel, at the request of the UN General Assembly it organized consultation meetings at country and regional levels to build a joint policy framework called "Towards Universal Access," which were endorsed by all UNAIDS partners and is now conceived as worldwide guidance for internationally recognized policy standards.

The appropriation of this programmatic shift by Cosponsors has been uneven. On the one hand, Cosponsors have paid particular attention to these joint objectives when it came to providing the UNAIDS governing board and donors with data and information in progress reports. They have had to align their performance indicators to these objectives. Greater effort and resources have been dedicated to conducting various assessments, reviews, and evaluation of UNAIDS efforts in selected areas of activities. On the other hand, Cosponsors continue to base their global strategies on their own priorities. Their programmes on AIDS scarcely reflect UNAIDS as a family and do not focus on the expected "key results."

Third, policy harmonization may appear irrelevant without a clear identification of the UN agencies' respective jurisdictions with regard to the epidemic. In 2005, the GTT enjoined the Cosponsors to make substantial efforts to clarify their mandates, in order to put an end to competition among agencies, programmatic fragmentation, policy overlaps and gaps, and lack of accountability. The Secretariat seized these recommendations and conducted the elaboration of a "UNAIDS Division of Labor", which assigned each Cosponsor to specific policy areas, depending on their mandate and their "comparative advantage" in the field. For instance, UNICEF is responsible for the support of orphans and vulnerable children, UNESCO for HIV prevention in educational institutions, UNFPA for prevention among key populations, and UNHCR for all activity related to refugees and internally displaced people.

Four, coordination of UN bureaucracies remains one of the primary objectives of UNAIDS.

From coordination depends the capacity of the UN system to integrate the various UN agencies' sectoral approaches into a coherent policy framework. It is also crucial in the provision of technical assistance to support governments and national stakeholders in implementing AIDS responses in various fields (e.g. public health, education, finance, agriculture). It is essential for building results-focused and cost-effective strategies against the epidemic. With the support of Cosponsors having large operational capacities on the ground (WHO, UNDP and UNICEF), the Secretariat participated in the setting of new vertical mechanisms to channel UN assistance to a variety of beneficiaries (national administrations, civil society organizations, the private sector, and sometimes bilateral organizations and other UN agencies). The Secretariat also participated in the setting new support desks ("Technical Support Facilities") in nearly 60 countries, tasked with helping identify and contact the relevant experts who can assist national authorities and stakeholders in AIDS responses. In 2006, it also established a permanent forum ("the Global Implementation Support Team") bringing together a limited number of UN agencies, funding organizations, bilateral donors, and NGOs to build rapid and coordinated technical responses to requests from governments. As stated by Le [START_REF] Lidec | Ordre institutionnel et genèse des réformes[END_REF], the activity of reform entrepreneurs within public administrations should not be viewed as a "heroic activity." It always takes place in systems of actors that generate both resistance and incentives to bureaucratic change. Therefore, the Secretariat's participation in the UNAIDS reform policy cannot be dissociated from the configuration of Cosponsors, donors and member states, and other actors (e.g. members of the GTT, the Boston Consulting Group), in a context of global AIDS governance characterized by a greater exposure of international organizations to their environment. Nevertheless, this article suggests that the Secretariat also gained bureaucratic authority by promoting the reform, along the four criteria identified by Barnett and Finnemore (2004, 20): rational-legal (ability to make general, impersonal rules that order and classify the world), delegated (ability to represent the will of member states), moral (ability to serve the interests of the community and to defend universal values), and expert (ability to deploy specialized and technical knowledge).

Conclusion

The analysis of the UNAIDS Programme offers insights into understanding the organizational processes that go with management reforms in multilateral agencies. In particular, it shows that reforms are implemented through interactions driven by both coercion and opportunities.

The UNAIDS case demonstrates that UN agencies are not likely to enter into a process of management reform by themselves, despite they participate in an sui generis interorganizational system tailor-made to overcome recurring governance challenges faced by international bureaucracies -such as institutional complexity, coordination problems, competing policy agendas, and overlapping activities. As most other international organizations, they are bureaucratic entities, protecting their autonomy and focusing on their own expansion. They tend to reproduce organizational patterns, practices and routines, which were institutionalized during past activities. They do not systematically import norms and prescriptions from their environment. By contrast, external pressure -which can be diffuse (circulation of ideas) or concentrate (direct interventions from principals and partners) -may contribute to induce organizational change and policy shifts. In the UNAIDS case, the choice to initiate management reforms results to a large extent from the growing pressure from the donor community, the diffusion of neomanagerial norms throughout international organizations, and structural change in the global AIDS governance.

Nevertheless, this article makes a connection between the disposition of UNAIDS actors to respond to external pressures and entrepreneurial activities within the Programme. It demonstrate that such pressures are likely to result in tangible organizational reforms only if they are appropriated and supported by actors who anticipate increased influence and control over their partners once reforms are implemented. The reforming process depends on the distribution of power among UNAIDS members and the interests of each member to strategically embark in the reform. As suggested in the article, it is necessary to explore the configuration of actors, their interests and intentions, when understanding the reasons why some of them decided to reappropriate the call for reform, to import and adapt principals' demands into a programmatic strategy, and to seek various supports (donors, other UN entities, a consulting firm) to sustain and legitimate the design of a policy response. This article argues that the reform of UNAIDS was associated with the aspiration of some its members to strengthen their authority and to challenge the initial distribution of resources within the Programme. It shows that the members with lower capacity, such as "new" Cosponsors or the Secretariat, had the strongest interest in promoting better efficiency and accountability of UNAIDS, through neomanagerial instruments, policy harmonization and coordination efforts. In particular, as a low-resource actor in the Programme, the Secretariat had a strong interest in pushing the reform agenda. It seized the external pressure as a window of opportunity to promote organizational change and, by doing so, to expand its coordinating role. However, it has also encountered some strong criticisms regarding the risk of selfexpansion and bureaucratization, as it may shift in the long term from the situation of a restricted coordination body to a new bureaucratic structure 16 .

Lastly, in the 2000s the growing attention to governance challenges in the AIDS response has had an impact on the agenda of UNAIDS organizations. As many multilateral organizations, the Secretariat and the Cosponsors have turned their primary attention to organizational challenges. This shift may be seen as a step forward, since it has helped UN agencies to move away from years of mismanagement, competition, and fragmentation of agency plans. Nevertheless, bureaucratic reform has become an end in itself: the focus on governance issues may well result in a reallocation of resources towards improving UN mechanisms rather than focusing on the assistance needed by affected populations at the grass-root level. It can thus encourage UN professionals working on AIDS to concentrate primarily on organizational processes instead of paying greater attention to policy development. Gathering statistics that meet requirements set by new indicators and benchmarks, setting new coordinating mechanisms or adapting standard operating rules at all levels, may partly satisfy donors and other financial partners. But it takes a lot of energy, time, and money, which may divert the attention of UN experts from the urgent challenges they ought to be taking up. As often demonstrated in the scientific literature on public organizations, actual bureaucratic change hardly reflects the intentions of the reformers. Any reform has hidden costs and unanticipated side-effects that should always be questioned.

REFERENCE LIST

-

  Barnett, Michael, and Martha Finnemore. 2004. Rules for the World: International Organizations in Global Politics. Ithaca and London: Cornell University Press. -Bauer, Michael W., and Christoph Knill, Hrsg. 2007. Management Reforms in International Organizations. Baden-Baden, Nomos. -Baumann, Soo Mee, Markus Hagel, and Barbara Kobler. 2007. Management in Change: the Reform Broker Concept, in Michael W. Bauer and Christoph Knill, eds. Management Reforms in International Organizations. Baden-Baden: Nomos. -Bezes, Philippe. 2009. Réinventer l'État. Les réformes de l'administration française (1962-2008), Paris: PUF. -Boswell, Cristina. 2008. Evasion, Reinterpretation and Decoupling: European Commission Responses to the 'External Dimension' of Immigration and Asylum. West European Politics 31 (3): 491-512. -Christensen, Tom, Per Laegreid, Paul G. Roness, and Kjell Arne Rovik. 2007. Organization Theory and the Public Sector: Instrument, Culture and Myth. London: Routledge. -Cini, Michelle. 1996. The European Commission: Leadership, Culture and Administration in the EU Commission. Manchester: Manchester University Press. -Common, Richard K. 1998. Convergence and transfer: a review of the globalisation of new public management. International Journal of Public Sector Management 11 (6): 11 p.

Public entrepreneurs may be defined as all individual or collective actors who mobilize resources and develop strategies to build, disseminate and/or implement innovative solutions within organizations of the public sector[START_REF] Schneider | Public Entrepreneurs: Agents for Change in American Government[END_REF].

The circulation of policy ideas that might have nurtured UNAIDS during the first decade of the Joint Programme is discussed elsewhere[START_REF] Nay | Policy Transfer and Bureaucratic Influence in the United Nations: The case of AIDS[END_REF]).

For instance, in UN bureaucracies, this can include secretariats, departments, governing bodies, top-level bureaucrats, diplomats, unions, oversight committees, and evaluation teams.

The degree of exposure of multilateral agencies to external pressure may vary from one organization to the other(Barnett and Finnemore 2004; Boswell 2008).

The MonterreyConference (2002), the Rome Forum onHarmonization (2003), the Marrakech Round Table on Results-Based Management (2004), the Paris Declaration on Aid Effectiveness (2005), the 2005 UN World Summit, and, more recently, the Accra High-Level Forum on Aid Effectiveness (2008).

TheUN "Millennium Declaration" (2000) or the UN Declaration of Commitment on HIV/AIDS (2001).

The UNDG was created in 1997 to improve effectiveness of operational development agencies. The three UN agencies are, together with WFP, chairing the Executive Committee of UNDG, with the mandate of designing system-wide guidance to coordinate, harmonize and align UN development programmes at the country-level

The consequences of UNAIDS administrative reforms are not addressed in this paper. They are studied elsewhere[START_REF] Nay | Administrative Reform in International Organizations: the case of the Joint United Nations Programme on HIV/AIDS[END_REF]

Public Administration Reform -HIV and Administration -New Public Management -Public Administration -Public author while he was working as a special advisor to UNESCO. The observation was consolidated by several semi-directed interviews carried out with former and current UN staff members;


Isabelle Gruais
email: isabelle.gruais@univ-rennes1.fr

Dan Poliševski

Dan Polişevschi

Homogenization of fluid-porous interface coupling in a biconnected fractured media

Keywords: fractured porous media, Stokes flow, Beavers-Joseph interface, homogenization, two-scale convergence Mathematics Subject Classification (2010) 35B27, 76M50, 76S05

The modelization of mass transfer through biconnected fractured porous media is studied by homogenizing the coupling between the Darcyan percolation and the viscous Stokes flow on their interface governed by the Beavers-Joseph law. The case of high transmission coefficients is considered. The asymptotic behaviour is completely described with the help of the solutions of some specific local problems and of a non homogeneous Neumann problem defined by the effective permeability tensor.

Introduction

Damaged porosity is the realistic counterpart of the model of porous media that was successfully recovered by means of homogenization methods based on formal asymptotic expansions in [START_REF] Sanchez-Palencia | Non-Homogeneous Media and Vibration Theory[END_REF] and later proved in [START_REF] Tartar | Incompressible fluid flow in a porous medium. Convergence of the homogenization process[END_REF] in its main part, namely the pressure problem. Variants including the influence of cracks have been studied in [START_REF] Barenblatt | On basic conceptions of the theory of homogeneous fluids seepage in fractured rocks (in Russian)[END_REF], [START_REF] Ene | Model of diffusion in partially fissured media[END_REF] based on an adequate choice of the physical model, see [START_REF] Barenblatt | On basic conceptions of the theory of homogeneous fluids seepage in fractured rocks (in Russian)[END_REF]- [START_REF] Beavers | Boundary conditions at a naturally permeable wall[END_REF], [START_REF] Jäger | Modeling effective interface laws for transport phenomena between an unconfined fluid and a porous medium using homogenization[END_REF]- [START_REF] Mikelić | Effets inertiels pour un écoulement stationnaire visqueux incompressible dans un milieu poreux[END_REF], [START_REF] Saffman | On the boundary condition at the interface of a porous medium[END_REF] where this issue is taken into account. An important assumption in homogenization theory dealing with porous media is the periodicity of the distribution of inclusions [START_REF] Cioranescu | Homogenization in open sets with holes[END_REF], [START_REF] Sanchez-Palencia | Non-Homogeneous Media and Vibration Theory[END_REF], [START_REF] Tartar | Incompressible fluid flow in a porous medium. Convergence of the homogenization process[END_REF], which has given rise to the periodicity-based two-scale convergence method of the pioneering article [START_REF] Nguetseng | A general convergence result for a functional related to the theory of homogenization[END_REF] and numerous improvements by [START_REF] Allaire | Homogenization of the Stokes flow in a connected porous medium[END_REF], [START_REF] Allaire | Homogenization and two-scale convergence[END_REF], [START_REF] Neuss-Radu | Some extensions of two-scale convergence[END_REF]. Darcy's law results from the homogenization theory applied to a periodic distribution of solid blocks immersed in a Stokes fluid. The asymptotic analysis was performed with the help of a restriction operator, which enables a natural extension of the pressure in the blocks. The next step was to consider transmission problems which proved to be a difficult question to handle in asymptotic analysis. In this direction, we have already studied (see [START_REF] Gruais | Fluid flows through fractured porous media along Beavers-Joseph interfaces[END_REF]) the Stokes problem immersed in a porous medium when the interface is governed by the Beavers-Joseph law. The two-component model is that of a porous medium perforated by cracks filled with Stokes fluid interacting with the ambiant porous medium through Beavers-Joseph conditions, in the case of bounded transfer coefficient. The study is handled by the two-scale convergence method and gives rise to a coupled model between a microscopic Stokes flow and a macroscopic Darcy law.

We consider here an incompressible viscous fluid flow in a periodically structured domain consisting of two interowen regions, separated by an interface. The first region represents the system of fissures which form the connected fracture, where the viscous flow is governed by the Stokes system. The second region, which may be also connected, stands for a porous structure of a certain permeability, where the flow is governed by Darcy's law. These two flows are coupled on the interface by the Saffman's variant [START_REF] Saffman | On the boundary condition at the interface of a porous medium[END_REF] of the Beavers-Joseph condition [START_REF] Beavers | Boundary conditions at a naturally permeable wall[END_REF], [START_REF] Jones | Low Reynolds number flow past a porous spherical shell[END_REF] which was confirmed by [START_REF] Jäger | Modeling effective interface laws for transport phenomena between an unconfined fluid and a porous medium using homogenization[END_REF] as the limit of a homogenization process. Besides the continuity of the normal component of the velocity, it imposes the proportionality of the tangential component of the viscous stress. The local problem has vanishing tangential velocity at the interface, which is linking both components of the corresponding microscopic cell problem while being coupled to a macroscopic Darcy law as well. The asymptotic behaviour is completely described with the help of the solutions of the local problems and of a non homogeneous Neumann problem defined by an effective permeability tensor.

The paper is organized as follows. The mathematical problem is presented in Section 2 along with a priori estimates derived from it. The coupling between the porous medium submitted to Darcy's law and the Stokes flow is described in details in Section 3. In particular, the scalings of both components are linked through the modelization of the interface which plays an important part in the asymptotic study. Compactness properties of the sequence of problems are studied in Section 4. The limit problem is introduced in Theorem 7 of Section 5 and described thereafter in Theorem 8. It consists of a macroscopic Darcy system characterized by a permeability tensor having the advantage of being easily computable through a local cell problem.

The properties of the two-connected components structure

Let Ω be an open connected bounded set in R N (N ≥ 2), locally located on one side of the boundary ∂Ω, a Lipschitz manifold composed of a finite number of connected components.

Let Y f be a Lipschitz open connected subset of the unit cube Y =]0, 1[ N , such that the intersections of ∂Y f with ∂Y are reproduced identically on the opposite faces of the cube without reaching the edges.

Repeating Y by periodicity, we assume that the reunion of all the Ȳf parts, denoted by R N f , is a connected domain in R N with a boundary of class C 2 , such that ∂Y f is Lipschitz-continuous. Defining Y s = Y \ Y f , we assume also that the reunion of all the Ȳs parts is a connected domain in R N . We set the origin of the coordinates system in such a point that there exists δ > 0 for which

B(0, δ) ⊂ R N s = R N \ R N f . The normal on Γ = Y f ∩ Y s , outward with respect to Y f , is denoted by ν.
For any ε ∈]0, 1[ we denote

Z ε = {k ∈ Z N , εk + εY ⊆ Ω} (2.1)
I ε = {k ∈ Z ε , εk ± εe i + εY ⊆ Ω, ∀i ∈ 1, N } (2.2)
where e i are the unit vectors of the canonical basis in R N . Finally, we define the system of fissures by

Ω εf = int ∪ k∈Iε (εk + ε Ȳf ) (2.3)
and the porous matrix of our structure by Ω εs = Ω\ Ωεf . The interface between the porous blocks and the fluid is denoted by

Γ ε = ∂Ω εf .
Obviously, Ω εs and Ω εf are connected and the fracture ratios of this structure have the property:

|Ω εf |/|Ω| → m := |Y f | ∈]0, 1[, when ε → 0.
A useful property of the present structure is the existence of a bounded extension operator (see [START_REF] Poliševski | Basic homogenization results for a biconnected ǫ-periodic structure[END_REF]) similar to that introduced in [START_REF] Cioranescu | Homogenization in open sets with holes[END_REF] (see also [START_REF] Conca | On the application of the homogenization theory to a class of problems arising in fluid mechanics[END_REF]) in the case of isolated fractures.

Theorem 1 There exists an extension operator P

ε : H 1 (Ω εf ) → H 1 (Ω) such that P ε u = u in Ω εf (2.4) |e(P ε u)| L 2 (Ω) ≤ C|e(u)| L 2 (Ω εf ) , ∀u ∈ H 1 (Ω εf ) (2.5)
where C is independent of ε.

For any h ∈ {s, f }, we recall the main inequalities that hold here.

Lemma 1 There exists C > 0 independent of ε such that

|u| L 2 (Ω εf ) ≤ Cε|∇u| L 2 (Ω εf ) , ∀u ∈ H 1 0 (Ω εf ) (2.6) |u| L 2 (Ωεs) ≤ C( ε|∇u| L 2 (Ωεs) + ε 1/2 |u| L 2 (∂Ωεs) ) , ∀u ∈ H 1 (Ω εs ) (2.

7)

Theorem 2 There exists C > 0 independent of ε such that

|p| L 2 (Ω εh )/R ≤ C ε |∇p| H -1 (Ω εh ) , ∀p ∈ L 2 (Ω εh ). ( 2

.8)

Corollary 1 There exists C > 0 independent of ε such that

|p| L 2 (Ω εh )/R ≤ C|∇p| L 2 (Ω εh ) , ∀p ∈ H 1 (Ω εh ). (2.9) Denoting χ εh (x) = χ h x ε
, where χ h is the characteristic function of Y h in Y , h ∈ {s, f }, we have a specific compactness result (see [START_REF] Poliševski | Basic homogenization results for a biconnected ǫ-periodic structure[END_REF]) for the pressure type estimates in H -1 (Ω εf ).

Theorem 3 For every ε ∈]0, 1[, let q ε ∈ L 2 (Ω εf ), such that for some constant C > 0 there hold:

Ω εf q ε (x) dx ≤ C, ∀ε ∈]0, 1[. (2.10)
|∇q ε | H -1 (Ω εf ) ≤ Cε, ∀ε ∈]0, 1[. (2.11)
Then, there exists q ∈ L 2 (Ω) such that, on some subsequence:

χ εf q ε 2 ⇀ χ f q.
(2.12)

The coupled Darcy-Stokes percolation

A model of fluid flow through a fractured porous medium is associated to our structure by assuming that there is a filtration flow in Ω εs obeying the Darcy's law and that there is a viscous flow in Ω εf governed by the Stokes system. These two flows are coupled by a Saffman's variant [START_REF] Saffman | On the boundary condition at the interface of a porous medium[END_REF] of the Beavers-Joseph condition [START_REF] Beavers | Boundary conditions at a naturally permeable wall[END_REF], [START_REF] Jones | Low Reynolds number flow past a porous spherical shell[END_REF]. The system is completed by an impermeability condition on ∂Ω:

divu ε = 0 in Ω (3.1)
A ε u ε = g -∇p εs in Ω εs , g ∈ L 2 (Ω) (3.2) σ εf ij = -p εf δ ij + ε 2 e ij (u ε ) in Ω εf (3.3) - ∂ ∂x j σ εf ij = g i in Ω εf (3.4) v εs • ν ε = v εf • ν ε on Γ ε , (3.5)
p εs ν ε i + σ εf ij ν ε j + ε r α ε (u εf i -(u εf • ν ε )ν ε i ) = 0 on Γ ε , r < 1 (3.6) u ε • n = 0 on ∂Ω, n the outward normal on ∂Ω, (3.7)
where u εs , u εf and p εs , p εf stand for the corresponding velocities and pressures,

A ε (x) = A x ε , A ∈ (C ∞ per (Y )) N ×N coercive, symmetric (3.8)
α ε (x) = α x ε ≥ α 0 > 0, α ∈ C 1 per (Y ) (3.9)
and e(v) denotes the symmetric tensor of the velocity gradient defined by

e ij (v) = 1 2 ∂v i ∂x j + ∂v j ∂x i .
As usual, we use the notations:

H 0 (div, Ω) = {v ∈ H(div, Ω), v • n = 0 on ∂Ω} (3.10) L 2 0 (Ω) = {p ∈ L 2 (Ω), Ω p = 0} (3.11) V 0 (div, Ω) = {v ∈ H 0 (div, Ω), divv = 0 in Ω} (3.12)
Next, we define

H ε = {v ∈ H 0 (div, Ω), v ∈ H 1 (Ω εf ) N }, (3.13)
the Hilbert space endowed with the scalar product

(u, v) Hε = Ωεs u•v + Ωεs divu divv +ε 2 Ω εf e(u) e(v)+ε r Γε (γ ε u-(γ ε ν u)ν ε )γ ε v, (3.14)
where γ ε and γ ε ν denote respectively the trace and the normal trace operators on Γ ε , while ν ε is the normal on Γ ε , outward with respect to Ω εf . The corresponding subspace of incompressible velocities is

V ε = {v ∈ V 0 (div, Ω), v ∈ H 1 (Ω εf ) N }. (3.15)
Via the corresponding Korn inequality, we obtain a specific inequality:

Lemma 2 There exists some constant C > 0, independent of ε, such that

|u| L 2 (Ω εf ) + ε|∇u| L 2 (Ω εf ) ≤ C|u| Hε , ∀u ∈ H ε . (3.16)
Looking for the variational formulation of the problem (3.1)-(3.7), we define for any u, v ∈ H ε and q ∈ L 2 0 (Ω)

a ε (u, v) := Ωεs A ε u • v + ε 2 Ω εf e(u) : e(v) + ε r Γε α ε (γ ε u -(γ ε ν u)ν ε ) • γ ε v (3.17) b ε (q, v) := - Ω q divv. ( 3.18)
We see that if the pair (u ε , p ε ) is a smooth solution of the problem (3.1)-(3.7), then it is also a solution of the following problem:

To find (u ε , p ε ) ∈ H ε × L 2 0 (Ω) such that a ε (u ε , v) + b ε (p ε , v) = Ω g ε • v, ∀v ∈ H ε , (3.19) b ε (q, u ε ) = 0, ∀q ∈ L 2 0 (Ω). ( 3

.20)

Theorem 4 There exists a unique pair

(u ε , p ε ) ∈ H ε × L 2 0 (Ω) solution of (3.

19)-(3.20).

Proof. As H 1 0 (Ω) is obviously included in H ε , the following inf-sup condition is easily satisfied by b ε :

∃C ε 1 > 0 such that inf q∈L 2 0 (Ω) sup v∈Hε b ε (q, v) |v| Hε |q| L 2 0 (Ω) ≥ C ε 1 .
The positivity conditions (3.8) and (3.9) imply that

∃C ε 2 > 0 such that a ε (v, v) ≥ C ε 2 |v| 2
Hε , ∀v ∈ H ε , that is the V ε -ellipticity of a ε . As we also have

V ε = {v ∈ H ε , b ε (q, v) = 0, ∀q ∈ L 2 0 (Ω)}, (3.21)
the proof is completed by Corollary 4.1, Ch. 1 of [START_REF] Girault | Finite Element Methods for Navier-Stokes Equations[END_REF].

A priori estimates and two-scale convergences

From now on, for any function ϕ defined on Ω×Y we shall use the notations

ϕ h = ϕ| Ω×Y h , φh = 1 |Y h | Y h ϕ(•, y)dy, h ∈ {s, f }, (4.1) φ = Y ϕ(•, y)dy, that is φ = (1 -m) φs + m φf . (4.2)
Also, for any sequence (ϕ ε ) ε , bounded in L 2 (Ω × Y ), we denote

ϕ ε 2 ⇀ ϕ iff ϕ ε is two-scale convergent to ϕ ∈ L 2 (Ω × Y ) in the sense of [2].
As usual, the asymptotic study starts by the search of a priori estimates of the velocity. Noticing that u ε ∈ V ε and setting v = u ε in (3.19) we get

|u ε | 2 Hε ≤ C|u ε | L 2 (Ω) (4.3)
and therefore:

|u ε | L 2 (Ωεs) ≤ C, ε|e(u ε )| L 2 (Ω εf ) ≤ C, ε r/2 |γ ε τ u ε | L 2 (Γε) ≤ C (4.4)
where, for any v ∈ H 1 (Ω εf ), we define

γ ε τ v ∈ H 1/2 (Γ ε ) by γ ε τ v := γ ε v -(γ ε ν v)ν ε . (4.5)
We find that (χ

εs u ε ) ε , (χ εf u ε ) ε and εχ εf ∂u ε ∂x i ε are bounded in (L 2 (Ω)) N , ∀i ∈ {1, 2, • • • , N }.
Using the compacity results of [START_REF] Nguetseng | A general convergence result for a functional related to the theory of homogenization[END_REF], ∃u ∈ L 2 (Ω × Y ) N such that, on some subsequence

u ε 2 ⇀ u (4.6) εχ εf ∇u ε i 2 ⇀ ∇ y u i (4.7) u ε ⇀ ũ ∈ V 0 (div, Ω) weakly in L 2 (Ω) N . (4.8)
Moreover, denoting

H per (div, Y ) = {ϕ ∈ H loc (div, R N ), ϕ is Y -periodic} (4.9) H 1 per (Y f ) = {ϕ ∈ H 1 loc (R N f ), ϕ is Y -periodic} (4.10)
we can sum the convergence results obtained until now by Theorem 5 There exists u ∈ L 2 (Ω, H per (div, Y )) with the properties:

u f ∈ L 2 (Ω, H 1 per (Y f ) N ), ũ ∈ H 0 (div, Ω), (4.11)
div y u = 0 in Ω × Y, (4.12)
divũ = 0 in Ω, (4.13)
such that the convergences (4.6) and (4.7) hold on some subsequence.

Next, we look for a priori estimates of the pressure. For this, set

v ∈ H ε in (3.19)-(3.20) such that v ∈ H 1 0 (Ω) N and v = 0 in Ω εf . (4.14)
Using the classical L 2 decomposition, we find that ∃p εs ∈ H 1 (Ω εs ) such that

∇p εs = A ε u ε -g ε ∈ L 2 (Ω εs ) (4.15)
and recalling (4.4), we find that there exists C > 0, independent of ε, such that

|∇p εs | L 2 (Ωεs) ≤ C. (4.16)
Consequently, using Corollary 1 we have also

|p εs -pεs | L 2 (Ωεs) ≤ C, C > 0 independent of ε. (4.17)
It remains to estimate pεs , and implicitly pεf , as pε = 0. We remark here that for any v ∈ H ε we get

|Ω| |Ω εf | pεs Γε γ ε ν v = Ωεs (p εs -pεs ) divv + Ω εf (p εf -pεf ) divv - Ω gv+ + Ωεs A ε u ε v + ε 2 Ω εf e(u ε ) : e(v) + ε r Γε α ε u ε (v -(γ ε ν v)ν ε ). (4.18)
In oder to conclude, we need a proper test function. For this, let

θ ∈ H 1 0 (Y ) N such that θ = ν on Γ . Next, we define θ ε ∈ H 1 0 (Ω) N by θ ε (x) =      θ x ε for x ∈ Ω ε = int ∪ k∈Iε (εk + ε Ȳ ) 0 for x ∈ Ω \ Ωε ; (4.19)
Setting v = εθ ε in (4.18), we finally get

|p εs | ≤ C|Γ ε | -1 1 + |θ ε | H 1 (Ω) , (4.20)
that is, (p εs ) ε and (p εf ) ε are bounded. (4.21)

Consequently, there exists C > 0 independent of ε, such that

|p εs | H 1 (Ωεs) ≤ C (4.22)
and using the compactness results of [START_REF] Allaire | Homogenization and two-scale convergence[END_REF], there exists p s ∈ H 1 (Ω) such that

χ εs p ε 2 ⇀ χ s p s ,
∇p εf , ψ H -1 (Ω εf ) = ε 2 Ω εf e(u ε ) e(ψ) - Ω εf g ε ψ, ∀ψ ∈ H 1 0 (Ω εf ) N . (4.24)
Consequently, recalling (4.4) and (4.21) we find that ∃C > 0, independent of ε, such that

|∇p εf | H -1 (Ω εf ) ≤ Cε. (4.25)
In the light of (4.21), (4.25) and applying Theorem 3 we find that there exists

p f ∈ L 2 (Ω) such that χ εf p ε 2 ⇀ χ f p f ,
p f = p s in L 2 (Ω). (4.27) Proof. Let ϕ ∈ D(Ω), ψ ∈ C ∞ per (Y ) N such that ψ = (γ ν ψ)ν on Γ and Γ γ ν ψ = 0. Set v ε i (x) = εϕ(x)ψ i x ε , ∀i ∈ {1, • • • , N },
in the variational formulation (3.19)- (3.20). Passing to the limit as ε → 0, we obtain

Γ γ ν ψ dσ Ω (p f (x) -p s (x))ϕ(x)dx = 0, ∀ϕ ∈ D(Ω),
which concludes the proof.

The convergence results concerning the pressure can be summed up by Theorem 6 There exists p ∈ H1 (Ω) := L 2 0 (Ω) ∩ H 1 (Ω) such that on some subsequence we have p ε 2 ⇀ p. (4.28)

A characteristic property issued from the Beavers-Joseph transfer condition is given by Lemma 4 The limit u satisfies:

γu f = (γ ν u f )ν on Ω × Γ. (4.29) Proof. For ϕ ∈ D(Ω, H 1 per (Y f ) N ) we define I ε (ϕ) = ε Γε α ε γ ε u ε (γ ε ϕ -(γ ε ν ϕ)ν ε ). (4.30)
As α and Γ are assumed smooth enough, there exists

Φ ∈ C ∞ (Ω, C 1 per (Y f )) N ×N such that Φ ij (x, y) = α(y)(ϕ i (x, y) -(ϕ(x, y) • ν(y))ν i (y))ν j (y) on Ω × Γ. (4.31)
Using the notation

Φ ε (x) = Φ x, x ε , (4.32)
we find that

I ε (ϕ) = ε ∂Ω εf Φ ε ij u ε i ν ε j dσ = = Ω εf ∂Φ ε ij ∂y j ε u ε i + ε Ω εf ∂Φ ij ∂x j ε u ε i + ε Ω εf Φ ε ij ∂u ε i ∂x j (4.33)
and a direct computation yields

lim ε→0 I ε (ϕ) = Ω×Y f ∂Φ ij ∂y j u f i + Φ ij ∂u f i ∂y j = Ω×Y f Φ ij u f i ν j = = Ω×Γ αγu f (γϕ -(γ ν ϕ)ν). ( 4

.34)

Setting v = ε 1-r ϕ as test function in (3.19) and passing to the limit with ε → 0 we find that

lim ε→0 I ε (ϕ) = 0 (4.35) that is, Ω×Γ αγu f (γϕ -(γ ν ϕ)ν)) = 0, ∀ϕ ∈ D(Ω, H 1 per (Y f ) N ), (4.36)
which yields the result.

Theorem 7 u and p introduced by Theorems 5 and 6 form a pair (u, p) ∈ X × M which is the unique solution of the problem (5.7)- (5.8).

Proof (3.19). Passing to the limit with ε → 0, taking advantage of the property γ ε τ ϕ ε = 0 by construction and using the two-scale convergences of Theorems 5 and 6, we obtain: where K is the symmetric and positive tensor defined by

. Let ϕ ∈ X ∩ D(Ω, C ∞ per (Y )) N . Denoting, as usual, ϕ ε (x) = ϕ x, x ε , we can set v(x) = ϕ ε (x) in
K ji = Y w i j .
(5.15)

Taking into account that the homogenized problem (5.7)-(5.8) is wellposed, then by straightforward verification we obtain the complete asymptotic behaviour of the solution:

Theorem 8 If (u ε , p ε ) ∈ H ε × L 2 0 (Ω)
is the solution of (3.19)- (3.20), then

u ε 2 ⇀ u = g i - ∂q ∂x i w i , (5.16)
p ε 2 ⇀ p = q, (5.17

)
where w i ∈ W and q ∈ H1 (Ω) are defined by (5.11) and (5.13)- (5.14).

  b ε (p ε , ϕ ε ) → -Ω×Ys p (div x ϕ) = b(p, ϕ),and a ε (u ε , ϕ ε ) → a(u, ϕ),which concludes the proof.The solution of the homogenized problem (5.7)-(5.8) has a further description which takes into account the so-called local problems and effective coefficients. For this, let us introduce the unique solution of the Darcy-Stokes system in Y , with the classical normal flow coupling conditions:For every i ∈ {1, • • • , N }, w i ∈ W is the solution of the problem:Ys Aw i ψ + Y f e y (w i ) e y (ψ) = Y ψ i , ∀ψ ∈ W (5.11)whereW= {w ∈ H per (div, Y ), w f ∈ H 1 per (Y f ) N , divw = 0 in Y, γ τ w f = 0 on Γ }. (5.12)Next, let q ∈ H1 (Ω) be the unique solution of the following compatible nonhomogeneous Neumann problem: div(K∇q) = div(Kg) in Ω, (5.13)K∇q • n = Kg • n on ∂Ω,(5.14)

  on some subsequence. (4.23) Next, we set ψ ∈ H ε in (3.19)-(3.20) such that ψ = 0 in Ω εs . It follows that ∃p εf ∈ L 2 (Ω εf ) such that

Acknowledgements. This work has been accomplished during the visit of D. Polişevschi at the I.R.M.A.R.'s Department of Mechanics (University of Rennes 1), whose support is gratefully acknowledged.

The two-scale homogenized problem

Here we find the so-called two-scale homogenized problem, verified by the limits u and p, given by Theorems 5 and 6. By proving that this problem is well-posed, it turns out that all the convergences in Theorems 5, 6 and so forth hold on the entire sequence. We conclude that the asymptotic behaviour of (u ε , p ε ) is completely described by (u, p), the unique solution of the homogenized problem.

Denoting

we introduce the Hilbert space

endowed with the scalar product

e y (u) : e y (ϕ).

(5.3)

we consider the problem:

where b is given by (5.6) and a is defined by

e y (v) : e y (ϕ).

(5.9)

Lemma 5 The problem (5.7)-(5.8) is well-defined.

Proof. First, we notice that

(5.10)

As the X 0 -ellipticity of a in X is obvious, the proof is completed by Corollary 4.1, Ch.1 of [START_REF] Girault | Finite Element Methods for Navier-Stokes Equations[END_REF], the corresponding inf-sup condition being justified via the surjectivity of div ∈ L(H 1 0 (Ω) N , L 2 0 (Ω)). The fact that (5.7)-(5.8) is the homogenized problem of the present case is justified below.


Jean-François Ponge

The structural links between ecology, evolution, and ethics: the virtuous epistemic circle.

The Structural Links between Ecology, Evolution, and Ethics: The Virtuous Epistemic Circle. Donato Bergandi. Springer, 2013. 179 pp., illus. $129.00 (ISBN 9789400750661 cloth).

The idea of a book devoted to the links between ecological science and philosophy, within the framework of present-day environmental concerns, was formed at an international workshop ("Between the philosophy of biology and the philosophy of ecology: evolutionisms, ecologies, and ethics") held in 2005 at the French National Museum of Natural History (MNHN) in Paris. Ten philosophers of science -from France, the United Kingdom, and the United States -contributed to the workshop, exchanging viewpoints and experiences in various environmental, ethical, and epistemological domains. This meeting resulted in The Structural Links between Ecology, Evolution, and Ethics: The Virtuous Epistemic Circle, a succinct book edited by Donato Bergandi, who also coordinated the workshop. Bergandi is a professor at the MNHN and is well known for his dissection of the concepts and methods now in use in systems ecology and for his stimulating debates about New concepts are also suggested throughout the book. For example, John Baird Callicott describes an "erotic ethic" of embracing human duty and our obligation to biotic communities. Environmental ethics is the subject of two contributions -Robin Attfield's questioning chapter called "Reconciling individualist and deeper environmentalist theories?" and Catherine Larrère's "Two philosophies of the environmental crisis.

The book is strewn with many innovative ideas, sometimes presented in a provocative manner. For instance, as a slap in the face to hierarchy theory (a highly favored theory among the Darwinian evangelists), Callicott suggests, with strong arguments, that organisms should be called superecosystems, reversing the paradigm of ecosystems as superorganisms, erected by Frederic E. [START_REF] Clements | Research Methods in Ecology[END_REF] to describe plant societies. Patrick Blandin, surfing on the contradictions between nature conservation (i.e., nothing must change) and evolution (i.e., everything is changing), states that the equilibrium paradigm must now be substituted by the cochange paradigm, which stems from the concept of EcoEvoEthics and is based on the evidence that we live in a permanently changing world.

The plea for the rights of animals by Tom Regan also deserves our attention. Aside from the psychological and biological reasons (e.g., their social behavior, their intelligence, their abilities for abstraction, and their capability of language), he poses the problem on moral grounds: "Like us, [animals] are in the world, aware of the world, aware of what happens to them.… [They] share the rights we have mentioned, including the right to be treated with respect" (p. 121).

Far from being a boring treatise, Structural Links has great educational value. The panel of contributors representing a variety of schools of thought is presented to the reader as an opportunity to embrace a wide landscape of philosophical problems within the fields of environmental science and nature conservation. I highly recommend this book to evolutionary biologists, systems ecologists, and environmental stakeholders, with the hope that it will contribute to new avenues of research in ecosystem resilience.

  (a) holism and reductionism, (b) cybernetics, and (c) emergence. The central figure of the book is that of Charles Darwin, whose research saturated evolutionary science and changed the way mankind sees nature -before the appearance of ecology and nature conservation at the end of the nineteenth century. Darwin's theories were largely propagated and, unfortunately, often distorted by his numerous followers -the Darwinian evangelists, as Michael Ruse humorously calls them in a chapter entitled "Evolution versus creation: a sibling rivalry?" Several Darwinian concepts are analyzed and criticized in the light of present-day knowledge: evolution (by Michael Ruse, in the above-mentioned chapter), chance (by Jean Gayon), time (by Jean-Marc Drouin), and adaptation (called adaptive management by Bryan G. Norton).