Cross-presenting human gammadelta T cells induce robust CD8+ alphabeta T cell responses.

Gammadelta T cells are implicated in host defense against microbes and tumors but their mode of function remains largely unresolved. Here, we have investigated the ability of activated human Vgamma9Vdelta2(+) T cells (termed gammadelta T-APCs) to cross-present microbial and tumor antigens to CD8(+) alphabeta T cells. Although this process is thought to be mediated best by DCs, adoptive transfer of ex vivo antigen-loaded, human DCs during immunotherapy of cancer patients has shown limited success. We report that gammadelta T-APCs take up and process soluble proteins and induce proliferation, target cell killing and cytokine production responses in antigen-experienced and naïve CD8(+) alphabeta T cells. Induction of APC functions in Vgamma9Vdelta2(+) T cells was accompanied by the up-regulation of costimulatory and MHC class I molecules. In contrast, the functional predominance of the immunoproteasome was a characteristic of gammadelta T cells irrespective of their state of activation. Gammadelta T-APCs were more efficient in antigen cross-presentation than monocyte-derived DCs, which is in contrast to the strong induction of CD4(+) alphabeta T cell responses by both types of APCs. Our study reveals unexpected properties of human gammadelta T-APCs in the induction of CD8(+) alphabeta T effector cells, and justifies their further exploration in immunotherapy research.

Empirical determination of the very high energy heavy quark cross section from nonaccelerator data

To cosmic rays incident near the horizon the Earth's atmosphere represents a beam dump with a slant depth reaching 36 000 g cm-2 at 90. The prompt decay of a heavy quark produced by very high energy cosmic ray showers will leave an unmistakable signature in this dump. We translate the failure of experiments to detect such a signal into an upper limit on the heavy quark hadroproduction cross section in the energy region beyond existing accelerators. Our results disfavor any rapid growth of the cross section or the gluon structure function beyond conservative estimates based on perturbative QCD.

Distorted-wave calculation of cross sections for inner-shell ionization by electron and positron impact

The relativistic distorted-wave Born approximation is used to calculate differential and total cross sections for inner shell ionization of neutral atoms by electron and positron impact. The target atom is described within the independent-electron approximation using the self-consistent Dirac-Fock-Slater potential. The distorting potential for the projectile is also set equal to the Dirac-Fock-Slater potential. For electrons, this guarantees orthogonality of all the orbitals involved and simplifies the calculation of exchange T-matrix elements. The interaction between the projectile and the target electrons is assumed to reduce to the instantaneous Coulomb interaction. The adopted numerical algorithm allows the calculation of differential and total cross sections for projectiles with kinetic energies ranging from the ionization threshold up to about ten times this value. Algorithm accuracy and stability are demonstrated by comparing differential cross sections calculated by our code with the distorting potential set to zero with equivalent results generated by a more robust code that uses the conventional plane-wave Born approximation. Sample calculation results are presented for ionization of K- and L-shells of various elements and compared with the available experimental data.

Spatial correlations and cross sections of clusters in the A + B -> 0 reaction

We consider the distribution of cross sections of clusters and the density-density correlation functions for the A+B¿0 reaction. We solve the reaction-diffusion equations numerically for random initial distributions of reactants. When both reactant species have the same diffusion coefficients the distribution of cross sections and the correlation functions scale with the diffusion length and obey superuniversal laws (independent of dimension). For different diffusion coefficients the correlation functions still scale, but the scaling functions depend on the dimension and on the diffusion coefficients. Furthermore, we display explicitly the peculiarities of the cluster-size distribution in one dimension.

The Dyadic and Triadic Therapeutic Alliance in Cross-cultural Health Care: The case of Hispanic American Patients

This research project conducted in the Psychology Department of the University of Lausanne (Switzerland) evaluated the therapeutic alliance with Hispanic American Patients. From the patient's perspective, the therapeutic alliance was explored in two types of frameworks: the dyadic and the triadic setting. The dyadic setting is the encounter between a therapist (health professional) and a patient who ideally share the same language. The triadic setting is the encounter of a therapist and a patient who speak different languages, but are able to interact using the help of an interpreter. My specific interest focuses on studying the therapeutic alliance in a cross- cultural setting through a mixed methodology. As part of the quantitative phase, non- parametric tests were used to analyze 55 questionnaires of the Therapeutic Alliance for Migrants - Health Professionals' version (QALM-PS). For the qualitative phase, a thematic analysis was used to analyze 20 transcript interviews. While no differences were found concerning the strength of the therapeutic alliance between the triadic and dyadic settings, results showed that the factors that enrich the therapeutic alliance with migrant patients depend more on an emotional alliance (bond) than on a rational alliance (agreements). Indeed, the positive relationship with the interpreter, and especially with the therapist, relies considerably on human qualities and moral values, bringing the conception of humanity as an important need when meeting foreign patients in health care settings. In addition, the quality of communication, which could be attributed to the type of interpreter in the triadic setting, plays an important role in the establishment of a positive therapeutic relationship. Ce projet de recherche mené au Département de psychologie de l'Université de Lausanne (Suisse) a évalué l'alliance thérapeutique avec les patients hispano-américains. Du point de vue du patient, l'alliance thérapeutique a été étudiée dans deux types de dispositifs: le cadre dyadique et triadique. Le cadre dyadique est la rencontre d'un thérapeute (professionnel de la santé) et d'un patient qui, idéalement, partagent la même langue. Le cadre triadique est la rencontre d'un thérapeute et d'un patient qui parlent différentes langues, mais sont capables d'interagir grâce à l'aide d'un interprète. Mon intérêt porte en particulier sur l'étude de l'alliance thérapeutique dans un cadre interculturel au travers d'une méthodologie mixte. Dans la phase quantitative, des tests non paramétriques ont été utilisés pour les analyses des 55 questionnaires de l'alliance thérapeutique pour les migrants, version - professionnels de la santé (QALM-PS). Pour la phase qualitative, une analyse thématique a été utilisée pour l'analyse des 20 entretiens transcrits. Bien qu'aucune différence n'a été constatée en ce qui concerne la force de l'alliance thérapeutique entre les cadres dyadiques et triadiques, les résultats montrent que les facteurs qui enrichissent l'alliance thérapeutique avec les patients migrants dépendent plus de l'alliance émotionnelle (lien) que sur une alliance rationnelle (accords). En effet, la relation positive avec l'interprète, et en particulier avec le thérapeute, repose en grande partie sur des qualités humaines et des valeurs morales, ce qui porte la conception de l'humanité comme un besoin important lors de la rencontre des patients étrangers dans un cadre de santé. En outre, la qualité de la communication, qui pourrait être attribuée au type d'interprète dans le cadre triadique, joue un rôle important dans l'établissement d'une relation thérapeutique positive.

Giving or Receiving Something for Sex: A Cross-Sectional Study of Transactional Sex among Ugandan University Students.

OBJECTIVE: This study sought to determine the prevalence of transactional sex among university students in Uganda and to assess the possible relationship between transactional sex and sexual coercion, physical violence, mental health, and alcohol use. METHODS: In 2010, 1954 undergraduate students at a Ugandan university responded to a self-administered questionnaire that assessed mental health, substance use, physical violence and sexual behaviors including sexual coercion and transactional sex. The prevalence of transactional sex was assessed and logistic regression analysis was performed to measure the associations between various risk factors and reporting transactional sex. RESULTS: Approximately 25% of the study sample reported having taken part in transactional sex, with more women reporting having accepted money, gifts or some compensation for sex, while more men reporting having paid, given a gift or otherwise compensated for sex. Sexual coercion in men and women was significantly associated with having accepted money, gifts or some compensation for sex. Men who were victims of physical violence in the last 12 months had higher probability of having accepted money, gifts or some compensation for sex than other men. Women who were victims of sexual coercion reported greater likelihood of having paid, given a gift or otherwise compensated for sex. Respondents who had been victims of physical violence in last 12 months, engaged in heavy episodic drinking and had poor mental health status were more likely to have paid, given a gift or otherwise compensated for sex. CONCLUSIONS: University students in Uganda are at high risk of transactional sex. Young men and women may be equally vulnerable to the risks and consequences of transactional sex and should be included in program initiatives to prevent transactional sex. The role of sexual coercion, physical violence, mental health, and alcohol use should be considered when designing interventions for countering transactional sex.

Cross section of a resonant-mass detector for scalar gravitational waves

Gravitationally coupled scalar fields, originally introduced by Jordan, Brans and Dicke to account for a non-constant gravitational coupling, are a prediction of many non-Einsteinian theories of gravity not excluding perturbative formulations of string theory. In this paper, we compute the cross sections for scattering and absorption of scalar and tensor gravitational waves by a resonant-mass detector in the framework of the Jordan-Brans-Dicke theory. The results are then specialized to the case of a detector of spherical shape and shown to reproduce those obtained in general relativity in a certain limit. Eventually we discuss the potential detectability of scalar waves emitted in a spherically symmetric gravitational collapse.

Radiological detection of dissolved cocaine

Introduction: Smuggling dissolved drugs, especially cocaine, in bottled liquids is a problem at borders nowadays. Common fluoroscopy of packages at the border cannot detect contaminated liquids. To find a dissolved drug, an immunological test using a drug-test panel has to be performed. This means that a control sample of the cargo must be opened to perform the test. As it is not possible to open all boxes, and as smugglers hide the drugcontaining boxes between regularly filled boxes, contaminated cargos can be overlooked. Investigators sometimes cannot perform the drug-test panel because they try not to arouse the smugglers' suspicion in order to follow the cargo and to find the recipient. Aims: The objective of our studies was to define non-invasive examination techniques to investigate cargos that are suspicions to contain dissolved cocaine without leaving traces on the samples. We examined vessels containing cocaine by radiological cross-section techniques such as multidetector computed tomography (MDCT) and magnetic resonance spectroscopy (MRS). Methods: In a previous study, we examined bottles of wine containing dissolved cocaine in different quantities using an MDCT unit. To distinguish between bottles containing red wine and those where cocaine was solved in the wine, cross sectional 2D-images have been reconstructed and the absorption of X-rays was quantified by measuring the mean density of the liquid inside the bottles. In our new study, we investigated phantoms containing cocaine dissolved in water with or without ethanol as well as cocaine dissolved in different sorts of commercially available wine by the use of a clinical magnetic resonance unit (3 tesla). To find out if dissolved cocaine could be detected, magnetic resonance spectroscopy (1H MRS) was performed. Results: By using a MDCT-unit and measuring the mean attenuation of X-rays, it is possible to distinguish weather substances are dissolved in a liquid or not, if a comparative liquid without any solutions is available. The increase of the mean density indicates the presence of dissolved substances without the possibility to identify the substance. By using magnetic resonance spectroscopy, dissolved cocaine can be clearly identified because it produces distinctive resonances in the spectrum. In contrast to MDCT, this technique shows a high sensitivity (detection of 1 mM cocaine in wine). Conclusions: Cross-sectional imaging techniques such as MDCT and MRS appropriated to examine cargos that are suspicious to contain dissolved cocaine. They allow to perform non-invasive investigations without leaving any trace on the cargo. While an MDCT scan can detect dissolved substances in liquids, identification of cocaine can be obtained by MR-spectroscopy. Acknowledgment: This work was supported by the Centre d'Imagerie BioMédicale (CIBM) of the University of Lausanne (UNIL), the Swiss Federal Institute of Technology Lausanne (EPFL), the University of Geneva (UniGe), the Centre Hospitalier Universitaire Vaudois (CHUV), the Hôpitaux Universitaire de Genève (HUG) and the Leenaards and the Jeantet Foundations.

Forecasting cosmic doomsday from CMB-LSS cross-correlations.

A broad class of dark energy models, which have been proposed in attempts at solving the cosmological constant problems, predict a late time variation of the equation of state with redshift. The variation occurs as a scalar field picks up speed on its way to negative values of the potential. The negative potential energy eventually turns the expansion into contraction and the local universe undergoes a big crunch. In this paper we show that cross-correlations of the cosmic microwave background anisotropy and matter distribution, in combination with other cosmological data, can be used to forecast the imminence of such cosmic doomsday.

Classical cross sections for relativistic spinning particles

We propose a definition of classical differential cross sections for particles with essentially nonplanar orbits, such as spinning ones. We give also a method for its computation. The calculations are carried out explicitly for electromagnetic, gravitational, and short-range scalar interactions up to the linear terms in the slow-motion approximation. The contribution of the spin-spin terms is found to be at best 10-6 times the post-Newtonian ones for the gravitational interaction.