Fluorescence methods to detect phase boundaries in lipid bilayer mixtures

Phase diagrams of lipid mixtures can show several different regions of phase coexistence, which include liquid-disordered, liquid-ordered, and gel phases. Some phase regions are small, and some have sharp boundaries. The identity of the phases, their location in composition space, and the nature of the transitions between the phases are important for understanding the behavior of lipid mixtures. High fidelity phase boundary detection requires high compositional resolution, on the order of 2% compositional increments. Sample artifacts, especially the precipitation of crystals of anhydrous cholesterol, can occur at higher cholesterol concentrations unless precautions are taken. Fluorescence resonance energy transfer (FRET) can be used quantitatively to find the phase boundaries and even partition coefficients of the dyes between coexisting phases, but only if data are properly corrected for non-FRET contributions. Self-quenching of the dye fluorescence can be significant, distorting the data at dye concentrations that intuitively might be considered acceptable. Even more simple than FRET experiments, measurements of single-dye fluorescence can be used to find phase boundaries. Both FRET and single-dye fluorescence readily detect the formation of phase domains that are much smaller than the wavelength of light, i.e. "nanoscopic" domains.     

Good Fences: The Importance of Setting Boundaries for Peaceful Coexistence

We consider the conditions of peace and violence among ethnic groups, testing a theory designed to predict the locations of violence and interventions that can promote peace. Characterizing the model''s success in predicting peace requires examples where peace prevails despite diversity. Switzerland is recognized as a country of peace, stability and prosperity. This is surprising because of its linguistic and religious diversity that in other parts of the world lead to conflict and violence. Here we analyze how peaceful stability is maintained. Our analysis shows that peace does not depend on integrated coexistence, but rather on well defined topographical and political boundaries separating groups, allowing for partial autonomy within a single country. In Switzerland, mountains and lakes are an important part of the boundaries between sharply defined linguistic areas. Political canton and circle (sub-canton) boundaries often separate religious groups. Where such boundaries do not appear to be sufficient, we find that specific aspects of the population distribution guarantee either sufficient separation or sufficient mixing to inhibit intergroup violence according to the quantitative theory of conflict. In exactly one region, a porous mountain range does not adequately separate linguistic groups and that region has experienced significant violent conflict, leading to the recent creation of the canton of Jura. Our analysis supports the hypothesis that violence between groups can be inhibited by physical and political boundaries. A similar analysis of the area of the former Yugoslavia shows that during widespread ethnic violence existing political boundaries did not coincide with the boundaries of distinct groups, but peace prevailed in specific areas where they did coincide. The success of peace in Switzerland may serve as a model to resolve conflict in other ethnically diverse countries and regions of the world.     

Building the State, Making the Nation: The Bases and Limits of State Centralization in "Modern" Peru

Most contemporary discussions of the nature of the state, state-building, and national consciousness formation are based on an oppositional model of state-society relations. In such models, state-building is depicted as a process in which the state must impose its central institutions and cultural/moral values on the recalcitrant local populations found within its territorial boundaries who, in resisting the state, cling to a myriad of local, oppositional identities. The present article critiques the oppositional model, proposes an alternative conceptualization that encompasses dimensions of cooperation and conflict in state-society relations, and thus points toward the forces that underlie the fragmentation and consolidation of states and national cultures.     

Notch signaling is not sufficient to define the affinity boundary between dorsal and ventral compartments

The developing limbs of Drosophila are subdivided into distinct cells populations known as compartments. Short-range interaction between cells in adjacent compartments induces expression of signaling molecules at the compartment boundaries. In addition to serving as the sources of long-range signals, compartment boundaries prevent mixing of the adjacent cell populations. One model for boundary formation proposes that affinity differences between compartments are defined autonomously as one aspect of compartment-specific cell identity. An alternative is that the affinity boundary depends on signaling between compartments. Here, we present evidence that the dorsal selector gene apterous plays a role in establishing the dorsoventral affinity boundary that is independent of Notch-mediated signaling between dorsal and ventral cells.     

Finding Money: Business and Charity in Auhelawa,Papua New Guinea

There is a growing consensus that money and the market principle have not led to a great transformation into modernity. Rather, market exchange is everywhere socially embedded. But what does this embedding consist of, structural limits, tactics of resistance, or moral boundaries? Auhelawa (Normanby Island, Papua New Guinea) have incorporated money into their local economy in a variety of ways which keep the logic of the market in check. The comparison between two modes of accumulation – business and charity – sheds light on the precise nature of embeddedness. Local entrepreneurs describe themselves as navigating dilemmas which arise from contradictions between accumulation and reciprocity. Church congregations, however, appear to have transcended this conflict by representing their charitable contributions of money as love-gifts which are not subject to reciprocity. While charity, like business, is an embedded form of accumulation, I argue that it creates links to an alternative hierarchy of values, and thus contains the potential to create a great transformation of its own.     

Moral and nonmoral innate constraints

Charles J. Lumsden and E.O. Wilson, in their writings together and individually, have proposed that human behaviors, whether moral or nonmoral, are governed by innate constraints (which they have termed epigenetic rules). I propose that if a genetic component of moral behavior is to be discovered, some sorting out of specifically moral from nonmoral innate constraints will be necessary. That some specifically moral innate constraits exist is evidenced by virtuous behaviors exhibited in nonhuman mammals, whose behavior is usually granted to be importantly governed by genetic factors. Propensities for such virtuous behaviors may have been passed to humans as highly conserved mammalian genes and continue to influence us. I propose that these constitute at least a rudimentary morality and may account in part for the moral intuitions. But other innate constraints which are nonmoral in nature interact with the specifically moral innate constraints and with culture to yield human moral decisions and actions. Any model which aims to identify the genetic component of moral behaviors or behaviors with moral import must provide not only a delineation of cultural causes but must also distinguish between those genetic causes which may have their origin in innate moral constraints from others which are fundamentally nonmoral because the critical faculty necessary to higher level human morality itself arises in part from innate constraints of a nonmoral type; i.e., the processes of inductive reasoning common to both ethics and science. Finally, humans who could bring the nonmoral evaluative capacities to bear upon whatever moral intuitions might be genetically conserved in mammalian heritage would have an advantage over similar beings who could not.     

Weaponising microbes for peace

There is much human disadvantage and unmet need in the world, including deficits in basic resources and services considered to be human rights, such as drinking water, sanitation and hygiene, healthy nutrition, access to basic healthcare, and a clean environment. Furthermore, there are substantive asymmetries in the distribution of key resources among peoples. These deficits and asymmetries can lead to local and regional crises among peoples competing for limited resources, which, in turn, can become sources of discontent and conflict. Such conflicts have the potential to escalate into regional wars and even lead to global instability. Ergo: in addition to moral and ethical imperatives to level up, to ensure that all peoples have basic resources and services essential for healthy living and to reduce inequalities, all nations have a self-interest to pursue with determination all available avenues to promote peace through reducing sources of conflicts in the world. Microorganisms and pertinent microbial technologies have unique and exceptional abilities to provide, or contribute to the provision of, basic resources and services that are lacking in many parts of the world, and thereby address key deficits that might constitute sources of conflict. However, the deployment of such technologies to this end is seriously underexploited. Here, we highlight some of the key available and emerging technologies that demand greater consideration and exploitation in endeavours to eliminate unnecessary deprivations, enable healthy lives of all and remove preventable grounds for competition over limited resources that can escalate into conflicts in the world. We exhort central actors: microbiologists, funding agencies and philanthropic organisations, politicians worldwide and international governmental and non-governmental organisations, to engage – in full partnership – with all relevant stakeholders, to ‘weaponise’ microbes and microbial technologies to fight resource deficits and asymmetries, in particular among the most vulnerable populations, and thereby create humanitarian conditions more conducive to harmony and peace.     

Religious expression in public schools: Kirpans in Canada,hijab in France

The present study analyses the status of the Arab minority in Israel, as revealed in Project Renewal, one of the largest and most ambitious programmes implemented in the country during the 1980s. The analysis discloses how conflicts over symbolic issues, such as the definition of the collective's boundaries, found their way on to the Project Renewal agenda, and how they affected the project's dynamics. The article analyses the intensity of the conflicts evoked by the issue of citizen participation in the neighbourhood. It interprets the clashes over neighbourhood representation as essentially resulting from a core conflict, one in which the very boundaries of Israel's moral community appeared to be at stake. The conclusions are based on an analytical distinction between those components of the programme that may be viewed as related to liberal citizenship rights, and those pertaining to republican citizenship rights, that is, elements touching upon the definition of the boundaries of the social collective and the moral community.     

Non-conflict theories for the evolution of genomic imprinting

Theories focused on kinship and the genetic conflict it induces are widely considered to be the primary explanations for the evolution of genomic imprinting. However, there have appeared many competing ideas that do not involve kinship/conflict. These ideas are often overlooked because kinship/conflict is entrenched in the literature, especially outside evolutionary biology. Here we provide a critical overview of these non-conflict theories, providing an accessible perspective into this literature. We suggest that some of these alternative hypotheses may, in fact, provide tenable explanations of the evolution of imprinting for at least some loci.     

Against Permitted Exploitation in Developing World Research Agreements

This paper examines the moral force of exploitation in developing world research agreements. Taking for granted that some clinical research which is conducted in the developing world but funded by developed world sponsors is exploitative, it asks whether a third party would be morally justified in enforcing limits on research agreements in order to ensure more fair and less exploitative outcomes. This question is particularly relevant when such exploitative transactions are entered into voluntarily by all relevant parties, and both research sponsors and host communities benefit from the resulting agreements. I show that defenders of the claim that exploitation ought to be permitted rely on a mischaracterization of certain forms of interference as unjustly paternalistic and two dubious empirical assumptions about the results of regulation. The view I put forward is that by evaluating a system of constraints on international research agreements, rather than individual transaction‐level interference, we can better assess the alternatives to permitting exploitative research agreements.     

Moral agency,moral worth and the question of double standards in medical research in developing countries

International regulations governing medical research, healthcare and medical practice, are, obviously, meant to be guidelines and not detailed procedural rules of thumb that can be applied unreflectively without any danger of doing moral wrong. Moreover, such regulations are meant to apply internationally, and no set of straight-jacketed rules of thumb can conceivably apply to all societies and communities of the world, extremely diverse and differently situated as they are. The mark of a good international guideline or regulation, in my view, is that it should provide a clear principle of action that applies equally to all global communities and societies without seeking to foist the particular or momentary moral dilemmas, quandaries, obsessions and preoccupations of some on all. In this paper, I propose to argue that, because moral obligations are obligations only from the point of view of a particular moral agent, we should avoid making the peculiar problems of any particular moral agent(s) the obsessive concern of all moral agents, and that we need, in particular, to make appropriate distinctions between the ethics of developed world research in the developing world, collaborative or cooperative research between the developed and developing worlds, developed world research in the developed world and developing world research in the developing world. A consequence of looking at things this way is that, while it should be clear that there are ethical concerns, imperatives and obligations at all levels, different standards may and, in fact, cannot but be applied in different contexts at different levels, without resorting to the use of double standards, which can never be morally justified. Finally, I venture to propose a formula for a solemn pledge of moral integrity and noble intent, from the perspective of the agent, that is to say, the investigator, sponsor and funder of any research, to complement and balance the widely accepted informed consent requirement, from the perspective of the patient, the subject of any biomedical research.     

Moral concepts set decision strategies to abstract values

Persons have different value preferences. Neuroimaging studies where value-based decisions in actual conflict situations were investigated suggest an important role of prefrontal and cingulate brain regions. General preferences, however, reflect a superordinate moral concept independent of actual situations as proposed in psychological and socioeconomic research. Here, the specific brain response would be influenced by abstract value systems and moral concepts. The neurobiological mechanisms underlying such responses are largely unknown. Using functional magnetic resonance imaging (fMRI) with a forced-choice paradigm on word pairs representing abstract values, we show that the brain handles such decisions depending on the person's superordinate moral concept. Persons with a predominant collectivistic (altruistic) value system applied a "balancing and weighing" strategy, recruiting brain regions of rostral inferior and intraparietal, and midcingulate and frontal cortex. Conversely, subjects with mainly individualistic (egocentric) value preferences applied a "fight-and-flight" strategy by recruiting the left amygdala. Finally, if subjects experience a value conflict when rejecting an alternative congruent to their own predominant value preference, comparable brain regions are activated as found in actual moral dilemma situations, i.e., midcingulate and dorsolateral prefrontal cortex. Our results demonstrate that superordinate moral concepts influence the strategy and the neural mechanisms in decision processes, independent of actual situations, showing that decisions are based on general neural principles. These findings provide a novel perspective to future sociological and economic research as well as to the analysis of social relations by focusing on abstract value systems as triggers of specific brain responses.     

Dynamic molecular structure of DPPC-DLPC-cholesterol ternary lipid system by spin-label electron spin resonance

The hydrated ternary lamellar lipid mixture of dipalmitoyl-PC/dilauroyl-PC/cholesterol (DPPC/DLPC/Chol) has been studied by electron spin resonance (ESR) to reveal the dynamic structure on a molecular level of the different phases that exist and coexist over virtually the full range of composition. The spectra for more than 100 different compositions at room temperature were analyzed by nonlinear least-squares fitting to provide the rotational diffusion rates and order parameters of the end-chain labeled phospholipid 16-PC. The ESR spectra exhibit substantial variation as a function of composition, even though the respective phases generally differ rather modestly from each other. The Lalpha and Lbeta phases are clearly distinguished, with the former exhibiting substantially lower ordering and greater motional rates, whereas the well-defined Lo phase exhibits the greatest ordering and relatively fast motional rates. Typically, smaller variations occur within a given phase. The ESR spectral analysis also yields phase boundaries and coexistence regions which are found to be consistent with previous results from fluorescence methods, although new features are found. Phase coexistence regions were in some cases confirmed by observing the existence of isosbestic points in the absorption mode ESR spectra from the phases. The dynamic structural properties of the DPPC-rich Lbeta and DLPC-rich Lalpha phases, within their two-phase coexistence region do not change with composition along a tie-line, but the ratio of the two phases follows the lever rule in accordance with thermodynamic principles. The analysis shows that 16-PC spin-label partitions nearly equally between the Lalpha and Lbeta phases, making it a useful probe for studying such coexisting phases. Extensive study of two-phase coexistence regions requires the determination of tie-lines, which were approximated in this study. However, a method is suggested to accurately determine the tie-lines by ESR.     

Conservation on International Boundaries: The Impact of Security Barriers on Selected Terrestrial Mammals in Four Protected Areas in Arizona,USA

Several thousand terrestrial protected areas (PAs) lie on international boundaries. Because international boundaries can be focal points for trade, illegal activity and development, such PAs can be vulnerable to a range of anthropogenic threats. There is an increasing trend towards the erection of international boundary infrastructure (including fences, barriers and ditches) in many parts of the world, which may reduce the risk of these anthropogenic threats to some PAs. However this may restrict home range and access to resources for some native species. We sought to understand the impacts of these two different types of threat by using camera traps to measure the activity level of humans, native and invasive mammals in four US PAs on the Mexican international boundary. Comparisons were made between treatment areas with barriers and those without. Results showed that puma and coati were more likely to appear in treatment areas without barriers, whereas humans were not observed more frequently in one treatment area over another. The suggestion is that the intermittent fencing present in this part of the world does affect some native species, but does not necessarily restrict the movement of humans (including illegal migrants), who may negatively impact native species.     

Relative temporal representations in Pavlovian conditioning

The transfer of relative temporal representations was assessed in a series of three experiments. In each experiment, rats (Rattus norvegicus) received one set of conditioned stimulus (CS) and intertrial interval (ITI) durations in Phase 1 and another set in Phase 2. The ratio between the CS and ITI intervals was either changed or maintained across phases. On the hypothesis that relative temporal representations are learned, groups receiving maintained temporal ratios across phases were expected to display greater change in responding upon encountering the new intervals. When the CS duration decreased across phases, maintaining the temporal ratio did lead to greater change in Day 1 of Phase 2 towards the final pattern of responding. However, when the CS increased across phases, maintaining the temporal ratio across phases did not facilitate adjustment to the new intervals, suggesting that extinction of previously reinforced times induced new learning. These results provide evidence that under some conditions, relative relationships in temporal maps may survive transformation-of-scale, like relative relationships in spatial maps.     

The acquisition of conscience and Developmental Systems Theory

Summary Proponents of Developmental Systems Theory (DST) argue that it offers an alternative to current research programs in biology that are built on the historic disjunction between evolutionary and developmental biology. In this paper I illustrate how DST can be used to account for the acquisition of an important component of moral agency, conscience. Susan Oyama, a major proponent of DST, has set moral issues outside the compass of DST. Thus, I examine her reasons for restricting DST to non-moral matters, and argue that they are not decisive. On the positive side, I argue that DST not only is compatible with attempts to describe and explain moral agency but also aids us in understanding it. In particular, I show how DST can provide a fruitful perspective for viewing some significant current findings and theories in moral developmental psychology about the acquisition of conscience. The familiar dichotomies resisted by DST, those between genes and environment, inherited and acquired, innate and learned, and biological and cultural, have also plagued human developmental psychology, including moral development. By bringing a DST perspective to the study of moral development, I illustrate how a DST perspective might offer a promising way to reconceive that phenomenon, and provide some insights into how further work in understanding the development of moral agency might proceed. Thus, I hope to contribute to the current efforts of proponents of DST to integrate developmental and evolutionary considerations.     

重塑组织边界：深圳医务社会工作的经验与反思

医务社会工作是医院与社会工作机构跨越组织边界的合作。通过对深圳医务社会工作的个案分析,揭示了医院与社会工作机构之间存在制度边界、物理边界、认同边界,具体表现为业务流程与管理规范的隔离、服务空间与信息流通的壁垒、主体间的认同困境,阻碍了医务社会工作的开展。医院主动开放边界的举措与社会工作机构主动渗透的策略促进了组织合作,重塑了组织边界,但也存在一定的不足。     

Quarantine,isolation and the duty of easy rescue in public health

We address the issue of whether, why and under what conditions, quarantine and isolation are morally justified, with a particular focus on measures implemented in the developing world. We argue that the benefits of quarantine and isolation justify some level of coercion or compulsion by the state, but that the state should be able to provide the strongest justification possible for implementing such measures. While a constrained form of consequentialism might provide a justification for such public health interventions, we argue that a stronger justification is provided by a principle of State Enforced Easy Rescue: a state may permissibly compel individuals to engage in activities that entail a small cost to them but a large benefit to others, because individuals have a moral duty of easy rescue to engage in those activities. The principle of State Enforced Easy Rescue gives rise to an Obligation Enforcement Requirement: the state should create the conditions such that submitting to coercive or compulsive measures becomes a fundamental moral duty of individuals, i.e. a duty of easy rescue. When the state can create such conditions, it has the strongest justification possible for implementing coercive or compulsive measures, because individuals have a moral duty to temporarily relinquish the rights that such measures would infringe. Our argument has significant implications for how public health emergencies in the developing world should be tackled. Where isolation and quarantine measures are necessary, states or the international community have a moral obligation to provide certain benefits to those quarantined or isolated.     

The Unbounded Space and Moral Transgression: Capitalist Expansion in West New Britain

ABSTRACT

Capitalist transformations in West New Britain Province, Papua New Guinea, have focused on setting boundaries on land and social relations as an efficient way to generate productive relations. But for the Maututu around Bialla town where the palm oil industry has been established the perception of productivity rests not on establishing boundaries but on exploring horizons. Recent dramatic changes to the economy and demography of this area have introduced moral conflict into Maututu endeavours to generate well-being. Maututu have responded to these conflicts in ways that continue to bring their indigenous morality to bear on the moral strategies pursued by state and capitalist forces.