Artificial Gravity Reveals that Economy of Action Determines the Stability of Sensorimotor Coordination

Background: When we move along in time with a piece of music, we synchronise the downward phase of our gesture with the beat. While it is easy to demonstrate this tendency, there is considerable debate as to its neural origins. It may have a structural basis, whereby the gravitational field acts as an orientation reference that biases the formulation of motor commands. Alternatively, it may be functional, and related to the economy with which motion assisted by gravity can be generated by the motor system

Unexpected features of branched flow through high-mobility two-dimensional electron gases

GaAs-based two-dimensional electron gases (2DEGs) show a wealth of remarkable electronic states, and serve as the basis for fast transistors, research on electrons in nanostructures, and prototypes of quantum-computing schemes. All these uses depend on the extremely low levels of disorder in GaAs 2DEGs, with low-temperature mean free paths ranging from microns to hundreds of microns. Here we study how disorder affects the spatial structure of electron transport by imaging electron flow in three different GaAs/AlGaAs 2DEGs, whose mobilities range over an order of magnitude. As expected, electrons flow along narrow branches that we find remain straight over a distance roughly proportional to the mean free path. We also observe two unanticipated phenomena in high-mobility samples. In our highest-mobility sample we observe an almost complete absence of sharp impurity or defect scattering, indicated by the complete suppression of quantum coherent interference fringes. Also, branched flow through the chaotic potential of a high-mobility sample remains stable to significant changes to the initial conditions of injected electrons.Comment: 22 pages, 4 figures, 1 tabl

“Excellence R Us”: university research and the fetishisation of excellence

The rhetoric of “excellence” is pervasive across the academy. It is used to refer to research outputs as well as researchers, theory and education, individuals and organisations, from art history to zoology. But does “excellence” actually mean anything? Does this pervasive narrative of “excellence” do any good? Drawing on a range of sources we interrogate “excellence” as a concept and find that it has no intrinsic meaning in academia. Rather it functions as a linguistic interchange mechanism. To investigate whether this linguistic function is useful we examine how the rhetoric of excellence combines with narratives of scarcity and competition to show that the hypercompetition that arises from the performance of “excellence” is completely at odds with the qualities of good research. We trace the roots of issues in reproducibility, fraud, and homophily to this rhetoric. But we also show that this rhetoric is an internal, and not primarily an external, imposition. We conclude by proposing an alternative rhetoric based on soundness and capacity-building. In the final analysis, it turns out that that “excellence” is not excellent. Used in its current unqualified form it is a pernicious and dangerous rhetoric that undermines the very foundations of good research and scholarship

Effects of external nutrient sources and extreme weather events on the nutrient budget of a Southern European coastal lagoon

The seasonal and annual nitrogen (N), phosphorus (P), and carbon (C) budgets of the mesotidal Ria Formosa lagoon, southern Portugal, were estimated to reveal the main inputs and outputs, the seasonal patterns, and how they may influence the ecological functioning of the system. The effects of extreme weather events such as long-lasting strong winds causing upwelling and strong rainfall were assessed. External nutrient inputs were quantified; ocean exchange was assessed in 24-h sampling campaigns, and final calculations were made using a hydrodynamic model of the lagoon. Rain and stream inputs were the main freshwater sources to the lagoon. However, wastewater treatment plant and groundwater discharges dominated nutrient input, together accounting for 98, 96, and 88 % of total C, N, and P input, respectively. Organic matter and nutrients were continuously exported to the ocean. This pattern was reversed following extreme events, such as strong winds in early summer that caused upwelling and after a period of heavy rainfall in late autumn. A principal component analysis (PCA) revealed that ammonium and organic N and C exchange were positively associated with temperature as opposed to pH and nitrate. These variables reflected mostly the benthic lagoon metabolism, whereas particulate P exchange was correlated to Chl a, indicating that this was more related to phytoplankton dynamics. The increase of stochastic events, as expected in climate change scenarios, may have strong effects on the ecological functioning of coastal lagoons, altering the C and nutrient budgets.Portuguese Science and Technology Foundation (FCT) [POCI/MAR/58427/2004, PPCDT/MAR/58427/2004]; Portuguese Science and Technology Foundation (FCT

Impact of efalizumab on patient-reported outcomes in high-need psoriasis patients: results of the international, randomized, placebo-controlled Phase III Clinical Experience Acquired with Raptiva (CLEAR) trial [NCT00256139]

BACKGROUND: Chronic psoriasis can negatively affect patients' lives. Assessing the impact of treatment on different aspects of a patient's health-related quality of life (HRQOL) is therefore important and relevant in trials of anti-psoriasis agents. The recombinant humanized IgG(1 )monoclonal antibody efalizumab targets multiple T-cell-dependent steps in the immunopathogenesis of psoriasis. Efalizumab has demonstrated safety and efficacy in several clinical trials, and improves patients' quality of life. Objective: To evaluate the impact of efalizumab on HRQOL and other patient-reported outcomes in patients with moderate to severe plaque psoriasis, including a large cohort of High-Need patients for whom at least 2 other systemic therapies were unsuitable because of lack of efficacy, intolerance, or contraindication. METHODS: A total of 793 patients were randomized in a 2:1 ratio to receive efalizumab 1 mg/kg/wk (n = 529) or placebo (n = 264) for 12 weeks. The study population included 526 High-Need patients (342 efalizumab, 184 placebo). The treatment was evaluated by patients using the HRQOL assessment tools Short Form-36 (SF-36) and Dermatology Life Quality Index (DLQI). Other patient-reported assessments included the Psoriasis Symptom Assessment (PSA), a visual analog scale (VAS) for itching, and the Patient's Global Psoriasis Assessment (PGPA). RESULTS: Efalizumab was associated with improvements at Week 12 from baseline in patient-reported outcomes, both in the total study population and in the High-Need cohort. Among all efalizumab-treated patients, the DLQI improved by 5.7 points from baseline to Week 12, relative to an improvement of 2.3 points for placebo patients (P < .001). Corresponding improvements in DLQI in the High-Need cohort were 5.4 points for efalizumab compared to 2.3 for placebo (P < .001). Improvements from baseline on the SF-36, PSA, PGPA, and itching VAS at Week 12 were also significantly greater in efalizumab-treated patients than for placebo. CONCLUSION: A 12-week course of efalizumab improved HRQOL and other patient-reported outcomes in patients with moderate to severe plaque psoriasis. The benefits of efalizumab therapy in High-Need patients were similar to those observed in the total study population, indicating that the beneficial impact of efalizumab on QOL is consistent regardless of disease severity, prior therapy, or contraindications to previous therapies

Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats

Peer reviewedPublisher PD

Harmful lifestyles' clustering among sexually active in-school adolescents in Zambia

<p>Abstract</p> <p>Background</p> <p>HIV is a leading cause of morbidity and mortality in Zambia. Like many other African nations with high HIV burden, heterosexual intercourse is the commonest mode of HIV spread. The estimation of prevalence and factors associated with sexual intercourse among in-school adolescents has potential to inform public health interventions aimed at reducing the burden of sex-related diseases in Zambia.</p> <p>Methods</p> <p>We carried out secondary analysis of the Zambia Global School-Based Health Survey (GSHS) 2004; a cross sectional survey that aims to study health-related behaviors among in-school adolescents. We estimated frequencies of relevant socio-demographic variables. The associations between selected explanatory variables and self-reported history of sexual intercourse within the last 12 months were assessed using logistic regression analysis.</p> <p>Results</p> <p>Data from 2136 in-school adolescents who participated in the Zambia Global School-Based Health Survey of 2004 were available for analysis. Out of these respondents, 13.4% reported that they had sexual intercourse in the past 12 months prior to the survey; 16.4% and 9.7% among males and females respectively. In multivariable logistic regression analysis, with age less than 15 years as the referent the adjusted odds ratio (AOR) of having engaged in sexual intercourse in adolescents of age 15 years, and those aged 16 years or more were 1.06 (95% CI 1.03–1.10) and 1.74 (95% 1.70–1.79) respectively. Compared to adolescents who had no close friends, adolescents who had one close friend were more likely to have had sexual intercourse, AOR = 1.28 (95% CI 1.24–1.32). Compared to adolescents who were not supervised by their parents, adolescents who were rarely or sometimes supervised by their parents were likely to have had sexual intercourse, and adolescents who were most of the time/always supervised by their parents were less likely to have had sexual intercourse; AORs 1.26 (95% CI 1.23–1.26) and 0.92 (95% CI 0.90–0.95) respectively. Compared to adolescents who did not smoke dagga, adolescents who smoked dagga 1 or 2 times, and those who smoked dagga 3 or more times in their lifetime were 70% and 25% more likely to have had sexual intercourse, respectively. Adolescents who drank alcohol in 1 or 2 days, and those who took alcohol in 3 or more days in a month preceding the survey were 12% and 9% more likely to have had sexual intercourse, respectively, compared to adolescents who did not drink alcohol in the 30 days prior to the survey. Furthermore, adolescents who had been drunk 1 or 2 times, and who had been drunk 3 or more times in a life time were 14% and 13% more likely to have had sexual intercourse compared to those who have never been drunk in their lifetime.</p> <p>Conclusion</p> <p>We identified a constellation of potentially harmful behaviours among adolescents in Zambia. Public health interventions aimed at reducing prevalence of sexual intercourse may be designed and implemented in a broader sense having recognized that sexually active adolescents may also be exposed to other problem behaviours.</p

Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us

Supernova remnants (SNRs) arise from the interaction between the ejecta of a supernova (SN) explosion and the surrounding circumstellar and interstellar medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However, to understand SNRs as a whole, large samples of SNRs must be assembled and studied. Here, we describe the radio, optical, and X-ray techniques which have been used to identify and characterize almost 300 Galactic SNRs and more than 1200 extragalactic SNRs. We then discuss which types of SNRs are being found and which are not. We examine the degree to which the luminosity functions, surface-brightness distributions and multi-wavelength comparisons of the samples can be interpreted to determine the class properties of SNRs and describe efforts to establish the type of SN explosion associated with a SNR. We conclude that in order to better understand the class properties of SNRs, it is more important to study (and obtain additional data on) the SNRs in galaxies with extant samples at multiple wavelength bands than it is to obtain samples of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and Paul Murdin. Final version available at https://doi.org/10.1007/978-3-319-20794-0_90-

Immigrant fertility in West Germany: is there a socialization effect in transitions to second and third births?

In this paper on immigrant fertility in West Germany, we estimate the transition rates to second and third births, using intensity-regression models. The data come from the German Socio-Economic Panel Study. We distinguish women of the first and the second immigrant generations originating from Turkey, the former Yugoslavia, Greece, Italy, and Spain, and compare their fertility levels to those of West German women. In the theoretical framework, we discuss competing hypotheses on migrant fertility. The findings support mainly the socialization hypothesis: the transition rates of first-generation immigrants vary by country of origin, and the fertility patterns of migrant descendants resemble more closely those of West Germans than those of the first immigrant generation. In addition, the analyses show that fertility differentials between immigrants and women of the indigenous population can largely, though not in full, be explained by compositional differences.Dans cet article relatif à la fécondité des immigrées en Allemagne, le passage du premier au deuxieme enfant et dans celui du deuxieme au troisieme enfant est estimé à partir de modèles de régression à risques instantanés. Les données utilisées proviennent de l’étude de Panel socio-économique allemand. On distingue les femmes immigrées de première ou de seconde génération originaires de Turquie, d’ex-Yougoslavie, de Grèce, d’Italie et d’Espagne, et leurs niveaux de fécondité sont comparés à ceux des femmes ouest-allemandes d’origine. Des hypothèses concurrentes sur la fécondité des immigrés sont discutées dans le cadre théorique. Les résultats vérifient principalement l’hypothèse de la socialisation : le passage au deuxieme et au troisieme enfant de la première génération d’immigrés varie selon le pays d’origine, et le profil de fécondité par âge des descendantes d’immigrées se rapproche plus de celui des femmes ouest-allemandes que de celui des immigrées de première génération. De plus, les analyses montrent que les différences de fécondité entre les immigrées et les femmes ouest-allemandes peuvent être en grande partie, mais pas totalement, expliquées par des différences de structure

In-situ evidence for dextral active motion at the Arabia-India plate boundary

International audienceThe Arabia-India plate boundary--also called theOwen fracture zone--is perhaps the least-known boundary among large tectonic plates1-6. Although it was identified early on as an example of a transform fault converting the divergent motion along the Carlsberg Ridge to convergent motion in the Himalayas7, its structure and rate of motion remains poorly constrained. Here we present the first direct evidence for active dextral strike-slip motion along this fault, based on seafloor multibeam mapping of the Arabia-India-Somalia triple junction in the northwest Indian Ocean. There is evidence for 12km of apparent strike-slip motion along the mapped segment of the Owen fracture zone, which is terminated to the south by a 50-km-wide pull-apart basin bounded by active faults. By evaluating these new constraints within the context of geodetic models of global plate motions, we determine a robust angular velocity for the Arabian plate relative to the Indian plate that predicts 2-4mmyr−1 dextral motion along the Owen fracture zone. This transformfault was probably initiated around 8 million years ago in response to a regional reorganization of plate velocities and directions8-11, which induced a change in configuration of the triple junction. Infrequent earthquakes of magnitude 7 and greater may occur along the Arabia-India plate boundary, unless deformation is in the formof aseismic creep