Skylab 4 visual observations project report

The Skylab 4 Visual Observations Project was undertaken to determine the ways in which man can contribute to future earth-orbital observational programs. The premission training consisted of 17 hours of lectures by scientists representing 16 disciplines and provided the crewmen information on observational and photographic procedures and the scientific significance of this information. During the Skylab 4 mission, more than 850 observations and 2000 photographs with the 70-millimeter Hasselblad and 35-millimeter Nikon cameras were obtained for many investigative areas. Preliminary results of the project indicate that man can obtain new and unique information to support satellite earth-survey programs because of his inherent capability to make selective observations, to integrate the information, and to record the data by describing and photographing the observational sites

Spatial and temporal adaptations that accompany increasing catching performance during learning.

The authors studied changes in performance and kinematics during the acquisition of a 1-handed catch. Participants were 8 women who took an intensive 2-week training program during which they evolved from poor catchers to subexpert catchers. An increased temporal consistency, shift in spatial location of ball-hand contact away from the body, and higher peak velocity of the transport of the hand toward the ball accompanied their improvement in catching performance. Moreover, novice catchers first adjusted spatial characteristics of the catch to the task constraints and fine-tuned temporal features only later during learning. A principal components analysis on a large set of kinematic variables indicated that a successful catch depends on (a) forward displacement of the hand and (b) the dynamics of the hand closure, thereby providing a kinematic underpinning for the traditional transport-manipulation dissociation in the grasping and catching literature. Copyright © 2007 Heldref Publications

Does probiotic consumption reduce antibiotic utilization for common acute infections? A systematic review and meta-analysis.

BackgroundOverall reduction of antibiotic use is a widely adopted public health goal. Given evidence that consuming probiotics reduce the incidence, duration and/or severity of certain types of common acute infections, we hypothesized that probiotics are associated with reduced antibiotic use. This systematic review of randomized controlled trials (RCTs) assessed the impact of probiotic supplementation (any strain, dose or duration), compared to placebo, on antibiotic utilization for common, acute infections in otherwise healthy people of all ages.MethodsWe searched 13 electronic databases including MEDLINE, Embase and CENTRAL from inception to 17th January 2017. Backward and forward citation searches were also conducted. Two reviewers independently selected studies for inclusion and extracted study data. We assessed risk of bias for individual studies using criteria adapted from the Centre for Reviews and Dissemination, and the quality of evidence for each outcome was assessed using the GRADE system. Studies that evaluated similar outcomes were pooled statistically in meta-analyses using a random-effects model.ResultsWe screened 1533 citations, and of these, 17 RCTs met our predefined inclusion criteria. All 17 were conducted in infants and/or children with a primary aim of preventing acute respiratory tract infections, acute lower digestive tract infections or acute otitis media. Included studies used 13 probiotic formulations, all comprising single or combination Lactobacillus and Bifidobacterium delivered in a range of food or supplement products. Mean duration of probiotic supplementation ranged from 4 days to 9 months. Trial quality was variable. Meta-analysis demonstrated that infants and children who received probiotics to prevent acute illnesses had a lower risk of being prescribed antibiotics, relative to those who received placebo (Pooled Relative Risk = 0.71, 95% CI: 0.54-0.94). When restricted to five studies with a low risk of bias, the pooled relative risk was 0.46 (95% CI: 0.23-0.97). Significant statistical heterogeneity was present in effect size estimates, which appeared to be due to one trial which could partly be considered as an outlier.ConclusionsProbiotics, provided to reduce the risk for common acute infections, may be associated with reduced antibiotic use in infants and children. Additional well-designed studies are needed to substantiate these findings in children and explore similar findings in other population groups

First evidence of a chemical call-for-help in Cataglyphis cursor ants

Dissertação de Mestrado, na área de especialização em Ciências Jurídico-Civilísticas/menção em Direito Civil, apresentada à Faculdade de Direito da Universidade de Coimbr

Topological Insulators

Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator, but have protected conducting states on their edge or surface. The 2D topological insulator is a quantum spin Hall insulator, which is a close cousin of the integer quantum Hall state. A 3D topological insulator supports novel spin polarized 2D Dirac fermions on its surface. In this Colloquium article we will review the theoretical foundation for these electronic states and describe recent experiments in which their signatures have been observed. We will describe transport experiments on HgCdTe quantum wells that demonstrate the existence of the edge states predicted for the quantum spin Hall insulator. We will then discuss experiments on Bi_{1-x}Sb_x, Bi_2 Se_3, Bi_2 Te_3 and Sb_2 Te_3 that establish these materials as 3D topological insulators and directly probe the topology of their surface states. We will then describe exotic states that can occur at the surface of a 3D topological insulator due to an induced energy gap. A magnetic gap leads to a novel quantum Hall state that gives rise to a topological magnetoelectric effect. A superconducting energy gap leads to a state that supports Majorana fermions, and may provide a new venue for realizing proposals for topological quantum computation. We will close by discussing prospects for observing these exotic states, a well as other potential device applications of topological insulators.Comment: 23 pages, 20 figures, Published versio

Anomalous absorption of bulk shear sagittal acoustic waves in a layered structure with viscous fluid

It is demonstrated theoretically that the absorptivity of bulk shear sagittal waves by an ultra-thin layer of viscous fluid between two different elastic media has a strong maximum (in some cases as good as 100%) at an optimal layer thickness. This thickness is usually much smaller than the penetration depths and lengths of transverse and longitudinal waves in the fluid. The angular dependencies of the absorptivity are demonstrated to have significant and unusual structure near critical angles of incidence. The effect of non-Newtonian properties and non-uniformities of the fluid layer on the absorptivity is also investigated. In particular, it is shown that the absorption in a thin layer of viscous fluid is much more sensitive to non-zero relaxation time(s) in the fluid layer than the absorption at an isolated solid-fluid interface.Comment: 14 pages, 8 figure

Improving the treatment and remission of major depression in homeless people with severe mental illness: the multicentric French Housing First (FHF) program. French Housing First Study Group Running title: Major depression in homeless people with severe mental disorders

International audienceObjectiveThe aim of this study was to investigate the factors associated with violent behavior in a large multicenter sample of Homeless Schizophrenia (SZ) and Bipolar Disorder (BD) (HSB) subjects.MethodsThis multicenter study was conducted in 4 French cities: Lille, Marseille, Paris and Toulouse. Violent behavior was defined by at least one episode of verbal or physical violence in the last 6 months.ResultsOverall, 675 HSB patients, mean aged 38 years and 82.5% men were included, 458 SZ (68.4%) and 212 BD (31.6%). During the 6 months before evaluation, 213 (34.3%) committed at least one physical or verbal violence. In multivariate analysis, violence has been associated with younger age (aOR = 0.96[0.94–0.99], p = .001), number of nights in the street (aOR = 1.01[1.01–1.01]), BD diagnosis (aOR = 1.63[1.01–2.65], p = .04), higher current illness severity (CGI score) (aOR = 1.32[1.07–1.64], p = .01), higher rates of current manic episode (aOR = 2.24[1.32–3.81], p = .002), current alcohol use disorder (aOR = 2.05 [1.33–3.15], p = .001), antisocial personality disorder (aOR = 2.51[1.55–4.07], p < .001) and with antidepressant consumption (aOR = 2.01[1.01–4.04], p = .04). No specific antipsychotic or mood stabilizer has been associated with decreased rates of violent behavior, however clozapine, lithium and carbamazepine remained poorly prescribed.ConclusionIn case of violent behavior in HSB subjects, clinicians should focus in priority on the treatment of mania, antidepressant iatrogenic effect and alcohol use disorder by pharmacological and non-pharmacological treatments. Clozapine, lithium and carbamazepine should be chosen as the treatments of reference in this population but may be hard to manage in some cases.The current clinical trial number is NCT01570712