Phase behaviour of dehydrated phosphatidylcholines

Dehydrated DLPC, DMPC, DPPC and DSPC have been characterised at temperatures below the diacyl carbon chain-melting transition (Tm), using DSC. For the first time, the existence of pre-Tm transition processes, which are, usually, only observed in the colloidal/liposomal state of saturated phospholipids have been detected for the dehydrated phosphatidylcholines. Temperature modulated differential scanning calorimetry (TMDSC) was used to characterize the several complex, overlapping pre-Tm transition processes. Kinetic studies of the chain-melting (Tm) transition show the activation energy dependence on α (conversion rate) i.e. activation energy decreases as the transition progresses, pointing to the importance of initial cooperative (intra- and inter-molecular) mobility. Furthermore the activation energy increases with increase in diacyl chain length of the phosphatidylcholines which supports the finding that greater molecular interactions of the polymer chain and its head groups in the dehydrated solid state lead to enhanced stability of dehydrated phosphatidylcholines

The European Union in the World — A Community of Values

These are momentous times in Europe. The Euro has been successfully introduced, the enlargement negotiations are approaching their climax, and the European Convention (“Convention”) is moving towards the drafting of a constitution for a new, continent-wide political entity. At the same time, unrest is manifest, particularly in two areas. On the one hand, many of our citizens, and not just the political elites, are dissatisfied with Europe\u27s performance on the world stage and are concerned about the maintenance of peace and security within the Union. In these areas they would like to see a strengthened, more effective entity-- “more Europe.” On the other hand, their disenchantment with the long reach of European Union (“EU” or “Union”) regulation in the first pillar area of economic policy is growing. The feeling of loss of local control over their destiny and a vague feeling of potential loss of identity within an ever more centralized polity is palpable. Here, they want “less Europe.” In the outside world, change is also the order of the day. The ice-sheet of bipolarity, which overlaid and hid the complexity of international relations during the Cold War, is breaking up at an ever-increasing speed and revealing a world in which two paradigms are competing to become the underlying ordering principles for the new century. The traditional paradigm of interacting Nation States, each pursuing its own separate interests, with alliances allowing the small to compete with the large, is alive and well, and its proponents like Machiavelli or Churchill continue to be in vogue in the literature of international relations and the rhetoric of world leaders. At the same time, there is a school of thought which points to the growing economic and ecological interdependence of our societies and the necessity for new forms of global governance to complement national action. It is also becoming abundantly clear that the concept of a “Nation State” is often a fiction, positing as it does an identity between the citizens of a State and the members of a culturally homogenous society. For both reasons, the concept of the Nation State as the principal actor on the world stage, is called into question. The experience of the Union with the sharing of State sovereignty is clearly related to the second paradigm and also to the EU\u27s firm support for the development of the United Nations (“U.N.”) as well as other elements of multilateral governance. It would hardly be wise to suggest that any foreign policy, and certainly not that of the EU, should be based only on this paradigm. Given the recurrent threats to security, which seem to be part of the human condition expressed by some as the “inevitability of war”--the defense of territorial integrity; action against threats of aggression; and resistance to crimes against humanity such as genocide--the ability to conduct a security policy based much more on the old paradigm of interacting interests will continue to be required. That the EU needs to develop such a capability will be taken here as a given. Such a crisis-management capability will be essential to the Union, but will be distinguished here from the more long-term elements of foreign policy, which can be thought of as being designed to reduce the need for crisis management in the context of a security policy to a minimum. The crisis-management area of policy will not be treated further here. The thesis of this Essay is that the same set of political concepts can serve as a guide to the future internal development of the EU and as the basis of such a long-term foreign policy. Furthermore, it suggests that neither should be seen in terms of the balancing of interests but rather, as the expression of a small list of fundamental values. The list is as follows: (1) the rule of law as the basis for relations between members of society; (2) the interaction between the democratic process and entrenched human rights in political decision-making; (3) the operation of competition within a market economy as the source of increasing prosperity; (4) the anchoring of the principle of solidarity among all members of society alongside that of the liberty of the individual; (5) the adoption of the principle of sustainability of all economic development; and (6) the preservation of separate identities and the maintenance of cultural diversity within society. These values can be seen as the answer to the question posed both, by citizens of the Union and by our fellow citizens of the world: “What does the EU stand for?” In exploring these values we should, however, remember that in the real world there will be occasions on which Realpolitik will intrude and the interest-based paradigm will prevail

Fine-Scale Phylogeographic Structure of Borrelia lusitaniae Revealed by Multilocus Sequence Typing

Borrelia lusitaniae is an Old World species of the Lyme borreliosis (LB) group of tick-borne spirochetes and prevails mainly in countries around the Mediterranean Basin. Lizards of the family Lacertidae have been identified as reservoir hosts of B. lusitaniae. These reptiles are highly structured geographically, indicating limited migration. In order to examine whether host geographic structure shapes the evolution and epidemiology of B. lusitaniae, we analyzed the phylogeographic population structure of this tick-borne bacterium using a recently developed multilocus sequence typing (MLST) scheme based on chromosomal housekeeping genes. A total of 2,099 questing nymphal and adult Ixodes ricinus ticks were collected in two climatically different regions of Portugal, being ∼130 km apart. All ticks were screened for spirochetes by direct PCR. Attempts to isolate strains yielded 16 cultures of B. lusitaniae in total. Uncontaminated cultures as well as infected ticks were included in this study. The results using MLST show that the regional B. lusitaniae populations constitute genetically distinct populations. In contrast, no clear phylogeographic signals were detected in sequences of the commonly used molecular markers ospA and ospC. The pronounced population structure of B. lusitaniae over a short geographic distance as captured by MLST of the housekeeping genes suggests that the migration rates of B. lusitaniae are rather low, most likely because the distribution of mediterranean lizard populations is highly parapatric. The study underlines the importance of vertebrate hosts in the geographic spread of tick-borne microparasites

The histone deacetylase inhibitor Trichostatin A modulates CD4+ T cell responses

BACKGROUND: Histone deacetylase inhibitors (HDACIs) induce hyperacetylation of core histones modulating chromatin structure and affecting gene expression. These compounds are also able to induce growth arrest, cell differentiation, and apoptotic cell death of tumor cells in vitro as well as in vivo. Even though several genes modulated by HDAC inhibition have been identified, those genes clearly responsible for the biological effects of these drugs have remained elusive. We investigated the pharmacological effect of the HDACI and potential anti-cancer agent Trichostatin A (TSA) on primary T cells. METHODS: To ascertain the effect of TSA on resting and activated T cells we used a model system where an enriched cell population consisting of primary T-cells was stimulated in vitro with immobilized anti-CD3/anti-CD28 antibodies whilst exposed to pharmacological concentrations of Trichostatin A. RESULTS: We found that this drug causes a rapid decline in cytokine expression, accumulation of cells in the G(1 )phase of the cell cycle, and induces apoptotic cell death. The mitochondrial respiratory chain (MRC) plays a critical role in the apoptotic response to TSA, as dissipation of mitochondrial membrane potential and reactive oxygen species (ROS) scavengers block TSA-induced T-cell death. Treatment of T cells with TSA results in the altered expression of a subset of genes involved in T cell responses, as assessed by microarray gene expression profiling. We also observed up- as well as down-regulation of various costimulatory/adhesion molecules, such as CD28 and CD154, important for T-cell function. CONCLUSIONS: Taken together, our findings indicate that HDAC inhibitors have an immunomodulatory potential that may contribute to the potency and specificity of these antineoplastic compounds and might be useful in the treatment of autoimmune disorders

Energy loss due to defect formation from \u3csup\u3e206\u3c/sup\u3ePb recoils in SuperCDMS germanium detectors

The Super Cryogenic Dark Matter Search experiment (SuperCDMS) at the Soudan Underground Laboratory studied energy loss associated with Frenkel defect formation in germanium crystals at mK temperatures using in situ 210Pb sources. We examine the spectrum of 206Pb nuclear recoils near its expected 103 keV endpoint energy and determine an energy loss of (6.08±0.18) %, which we attribute to defect formation. From this result and using TRIM simulations, we extract the first experimentally determined average displacement threshold energy of (19.7+0.6−0.5) eV for germanium. This has implications for the analysis thresholds of future germanium-based dark matter searches

First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 gram CDMS HV device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/c2. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 gram days). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations

Measurement of the single-spin asymmetry A y 0 in quasi-elastic 3He↑(e,e′n) scattering at 0.4 < Q 2 < 1.0 GeV/c 2

No abstract available