What makes a host profitable? Parasites balance host nutritive resources against immunity

Numerous host qualities can modulate parasite fitness, and among these, host nutritive resources and immunity are of prime importance. Indeed, parasite fitness increases with the amount of nutritive resources extracted from the host body and decreases with host immune response. To maximize fitness, parasites have therefore to balance these two host components. Yet, because host nutritive resources and immunity both increase with host body condition, it is unclear whether parasites perform better on hosts in prime, intermediate, or poor condition. We investigated blood meal size and survival of the ectoparasitic louse fly Crataerina melbae in relation to body condition and cutaneous immune response of their Alpine swift (Apus melba) nestling hosts. Louse flies took a smaller blood meal and lived a shorter period of time when feeding on nestlings that were experimentally food deprived or had their cutaneous immune response boosted with methionine. Consistent with these results, louse fly survival was the highest when feeding on nonexperimental nestlings in intermediate body condition. Our findings emphasize that although hosts in poor condition had a reduced immunocompetence, parasites may have avoided them because individuals in poor condition did not provide adequate resources. These findings highlight the fact that giving host immunocompetence primary consideration can result in a biased appraisal of host-parasite interactions

Position requirements for space station personnel and linkages to portable microcomputer performance assessment

The development and use of a menu of performance tests that can be self-administered on a portable microcomputer are investigated. In order to identify, develop, or otherwise select the relevant human capabilities/attributes to measure and hence include in the performance battery, it is essential that an analysis be conducted of the jobs or functions that will be performed throughout a space shuttle mission. The primary job analysis instrument, the Position Analysis Questionnaire (PAQ), is discussed in detail so the reader will have sufficient background for understanding the application of the instrument to the various work activities included within the scope of the study, and the derivation of the human requirements (abilities/attributes) from the PAQ analyses. The research methodology is described and includes the procedures used for gathering the PAQ data. The results are presented in detail with specific emphasis on identifying critical requirements that can be measured with a portable computerized assessment battery. A discussion of the results is given with implications for future research

Observation of Ising-like critical fluctuations in frustrated Josephson junction arrays with modulated coupling energies

We report the results of ac sheet conductance measurements performed on fully frustrated square arrays of Josephson junctions whose coupling energy is periodically modulated in one of the principal lattice directions. Such systems are predicted to exhibit two distinct transitions: a low-temperature Ising-like transition triggered by the proliferation of domain walls and a high-temperature transition driven by the vortex unbinding mechanism of the Beresinskii-Kosterlitz-Thouless (BKT) theory. Both the superfluid and dissipative components of the conductance are found to exhibit features which unambiguously demonstrate the existence of a double transition whose properties are consistent with the Ising-BKT scenario.Comment: To be published in Physica C (Proceedings of the 2nd European Conference in School Format 'Vortex Matter in Superconductors'

The contractile properties of vaginal myofibroblasts: Is the myofibroblasts contraction force test a valuable indication of future prolapse development?

Using a specific myofibroblast contraction test, we try to predict future utero-vaginal prolapse development in young primiparae women. We compare myofibroblast cultures of the vaginal wall in primiparae women (group 1), young multiparae women (group 2) and older multiparae women (group 3) who were operated on for severe utero-vaginal prolapse. A myofibroblast-mediated collagen gel contraction assay determined a contraction factor that was compared in the three groups of women. The myofibroblasts contraction factor after 24 and 48 hours was significantly higher in group 1 women (2.4 ± 0.6/4.4 ± 1.9) compared to group 2 (1.6 ± 0.3/ 1.8 ± 0.1) andgroup 3 (1.6 ± 0.3/1.8 ± 0.3), but showed no differences in group 1 women without (2.1 ± 0.5/3.5 ± 1.9) and with (2.7 ± 0.6/5.1 ± 1.7) cystocoele. Vaginal myofibroblasts of young women show better contraction forces than young women with severe utero-vaginal prolapse. The latter have a myofibroblast contraction factor similar to those of older post-menopausal women operated for the same conditio

Growth of Single Unit-Cell Superconducting La2−x_{2-x}Srx_xCuO4_{4} Films

We have developed an approach to grow high quality ultrathin films of La$_{2-x}$Sr$_x$CuO$_{4}$ with molecular beam epitaxy, by adding a homoepitaxial buffer layer in order to minimize the degradation of the film structure at the interface. The advantage of this method is to enable a further reduction of the minimal thickness of a superconducting La$_{1.9}$Sr$_{0.1}$CuO$_{4}$ film. The main result of our work is that a single unit cell (only two copper oxide planes) grown on a SrLaAlO$_4$ substrate exhibits a superconducting transition at 12.5 K (zero resistance) and an in-plane magnetic penetration depth $\lambda_{ab}(0)$ = 535 nm.Comment: to be published in "Solid State Electonics" special issue, conference proceedings of the 9th Workshop on Oxide Electronics, St-Pete Beach, FL, 20-23 november 2002 : 12 pages 4 figures in preprint versio

How to identify and recruit nurses to a survey 14 and 24 years after graduation in a context of scarce data: lessons learnt from the 2012 nurses at work pilot study on nurses' career paths.

BACKGROUND: Nursing workforce data are scarce in Switzerland, with no active national registry of nurses. The worldwide nursing shortage is also affecting Switzerland, so that evidence-based results of the nurses at work project on career paths and retention are needed as part of the health care system stewardship; nurses at work is a retrospective cohort study of nurses who graduated in Swiss nursing schools in the last 30 years. Results of the pilot study are presented here (process and feasibility). The objectives are (1) to determine the size and structure of the potential target population by approaching two test-cohorts of nursing graduates (1988 and 1998); (2) to test methods of identifying and reaching them 14 and 24 years after graduation; (3) to compute participation rates, and identify recruitment and participation biases. METHODS: Graduates' names were retrieved from 26 Swiss nursing schools: 488 nurses from the 1988 cohort and 597 from 1998 were invited to complete a web-based questionnaire. Initial updated addresses (n = 278, seed sample) were found using the Swiss Nursing Association member file. In addition, a snowball method was applied for recruitment, where directly-contacted respondents provided additional names of graduate mates or sent them the invitation. The study was further advertized through the main employers, study partners, and a press release. RESULTS: Participation rate was 26.5% (n = 287), higher for the older cohort of 1988 (29.7%, n = 145) than for 1998 (15.6%, n = 93). Additional nurses (n = 363) not belonging to the test cohorts also answered. All schools were represented among respondents. Only 18 respondents (6%) worked outside nursing or not at all. Among respondents, 94% would 'probably' or 'maybe' agree to participate in the main study. CONCLUSION: The pilot study demonstrated that targeted nurses could be identified and approached. There is an overwhelming interest in the project from them and from policymakers. Recommendations to increase nurses' participation rate for nurses at work include: (1) to open nurses at work recruitment to all nurses in Switzerland, while recreating cohorts post-hoc for relevant analysis; (2) to define a comprehensive communication strategy with special attention to graduate nurses who are harder to reach

Processus psychologiques de gestion du stress et régulation neuroendocrinienne chez les adolescents délinquants en institution fermée : une étude pilote [Psychological processes of stress management and neuroendocrine regulation in incarcerated adolescent offenders: A pilot study]

Adolescence is a stressful period where important biological, psychological and social changes occur. Adolescents are particularly vulnerable during this developmental period and can use various strategies to deal with daily stress, such as substance use or externalizing behaviors. In previous studies, stress in adolescents with externalizing behaviors was often linked to ineffective cognitive coping strategies (i.e., constructive thinking) and overlooking the biological aspects involved in stress management such as neuroendocrine regulation. Indeed, repeated activation of the hypothalamic-pituitary-adrenal (HPA) axis in chronic stress situations may have long-term effects on subsequent cortisol regulation and lead to psychological difficulties. It was also shown that basal cortisol levels are lower in adolescents with externalizing behaviors. This study aims to assess the links between constructive thinking and neuroendocrine regulation in adolescent offenders and their association with externalizing symptoms (e.g., aggression, delinquency, psychopathic traits, substance use). Identifying particular biopsychological patterns can help to better understand stress management in youth with externalizing behaviors and to improve clinical treatments. Sixteen adolescent males aged from 12 to 18 years were recruited in an institution for juvenile offenders. Exclusion criteria were insufficient reasoning abilities assessed using the Raven Matrices Test. Regarding psychological dimensions, constructive thinking was assessed through the Constructive thinking inventory (CTI), psychopathic traits through the Youth psychopathic traits inventory (YPI), externalizing behaviors through 30 items (out of 113) and 2 subscales (aggressive behavior and delinquency problems) from the Child behavior checklist-youth self-report (CBCL), and substance use through the Dep-ado. Regarding biological dimensions, cortisol daily secretion and regulation were assessed through saliva samples that were collected during 3 consecutive days (4 samples per day: directly after awakening, at 10 a.m., at 4 a.m., and before going to bed). Adolescent offenders presented maladaptative thinking styles and a particular neuroendocrine regulation in their daily management with stress. In particular, their level of cortisol in the morning was higher than those expected in a general population (20.34 nmol/L while the norm is around 10 nmol/L). They also showed more agressive and delinquent behaviors (CBCL) as well as more psychopathic traits (YPI) than the general population. Moreover, constructive thinking style was associated with personality and behavioral dimensions. Indeed, results indicated positive and significant correlations between categorical thinking style (CTI), psychopathic traits (YPI) (r=0.57, P=0.021) and externalizing behaviors (CBCL) (r=0.55, P=0.028). In other words, the more adolescent offenders used categorical thinking, the more they presented psychopathic traits and externalizing behaviors. With respect to the association between psychological and biological dimensions in stress management, we observed a significant and positive correlation between cortisol regulation and esoteric thinking (r=0.57, P=0.028) and a trend with superstitious thinking (r=0.47, P=0.075). The more adolescent offenders used esoteric and superstitious thinking, the poorer was their cortisol regulation. We also observed a trend between the life style scale of the YPI (i.e., impulsive, irresponsible) and the daily secretion of cortisol (r=0.51; P=0.052) as well as cortisol regulation (r=0.49, P=0.065). The more adolescent offenders presented psychopathic traits, the higher tended to be their daily secretion of cortisol and the poorer their cortisol regulation. Finally, cortisol regulation (r=0.54, P=0.038) and secretion (r=0.73, P=0.002) were significantly correlated with the DEP-Ado score. In other words, a poor cortisol regulation and a high secretion of cortisol seem to be associated with substance use. Adolescent offenders face an important amount of daily stress and do not always have the appropriate skills to deal with it. Indeed, we know from clinical experience that they often report a sense of hopelessness toward their lack of professional perspectives as well as familial conflicts which can be important stressors in addition to the incarceration in itself. Therefore, treatment aiming to improve psychic elaboration can help these adolescents to make their thinking styles more flexible and use more appropriate ways of coping with stress instead of externalizing behaviors and substance use. Moreover, considering the complex cases of these adolescents and the many changes of caregivers and institutions where they have lived, which can be important stressors as well, professionals working with these youth should be aware of their emotional reactions toward them and try to encourage continuity of care

Realization of an Inductance Scale Traceable to the Quantum Hall Effect Using an Automated Synchronous Sampling System

In this paper, the realization of an inductance scale from 1~$\mu$H to 10~H for frequencies ranging between 50~Hz to 20~kHz is presented. The scale is realized directly from a series of resistance standards using a fully automated synchronous sampling system. A careful systematic characterization of the system shows that the lowest uncertainties, around 12~$\mu$H/H, are obtained for inductances in the range from 10~mH to 100~mH at frequencies in the kHz range. This new measurement system which was successfully evaluated during an international comparison, provides a primary realization of the henry, directly traceable to the quantum Hall effect. An additional key feature of this system is its versatility. In addition to resistance-inductance (R-L) comparison, any kind of impedances can be compared: R-R, R-C, L-L or C-C, giving this sampling system a great potential of use in many laboratories around the world

Micromegas in a Bulk

In this paper we present a novel way to manufacture the bulk Micromegas detector. A simple process based on the PCB (Printed Circuit Board) technology is employed to produce the entire sensitive detector. Such fabrication process could be extended to very large area detectors made by the industry. The low cost fabrication together with the robustness of the electrode materials will make it extremely attractive for several applications ranging from particle physics and astrophysics to medicineComment: 6 pages, 4 figure

Fibroblast activation protein-α in fibrogenic disorders and cancer: more than a prolyl-specific peptidase?

Fibroblast activation protein-α (FAP-α) belongs to the family of prolyl-specific serine proteases. FAP-α displays both exopeptidase and endopeptidase/gelatinase/collagenase activities. FAP-α protein and/or activity have been associated with fibrosis, inflammation and cancer, but the protein is undetectable in most normal tissues. FAP-α is selectively expressed at sites of tissue remodeling and repair and enhances tumor progression, suggesting that this protease may be a therapeutic target to treat human disorders associated with fibrotic dysregulation. Areas covered: In this review, we summarize the mechanisms driving tissue fibrosis and describe some of the enzymes involved in fibrosis, concentrating on FAP-α. We describe its enzymatic properties, discuss the tools developed to control its activity and the problem of selectivity toward the other proteases of the family and outline its potential biological substrates. We also consider non-enzymatic functions of this protein and suggest that repression of FAP-α expression may represent therapeutic options. Expert opinion: Questions remain regarding the biological functions of FAP-α, either dependent or independent of its enzyme activity. However, as progress is underway to develop FAP-α-specific inhibitors and therapeutic antibodies, its role in diseases associated with fibrosis is starting to emerge, ultimately leading to novel therapeutic options for inflammatory and oncologic diseases