Proposed direct test of a certain type of noncontextuality in quantum mechanics

The noncontextuality of quantum mechanics can be directly tested by measuring two entangled particles with more than two outcomes per particle. The two associated contexts are "interlinked" by common observables.Comment: 9 pages 2 figure

Small-molecule lysophosphatidic acid receptor 5 (LPAR5) antagonists: versatile pharmacological tools to regulate inflammatory signaling in BV-2 microglia cells

Lysophosphatidic acid (LPA) species in the extracellular environment induce downstream signaling via six different G protein-coupled receptors (LPAR1-6). These signaling cascades are essential for normal brain development and function of the nervous system. However, in response to acute or chronic central nervous system (CNS) damage, LPA levels increase and aberrant signaling events can counteract brain function. Under neuro-inflammatory conditions signaling along the LPA/LPAR5 axis induces a potentially neurotoxic microglia phenotype indicating the need for new pharmacological intervention strategies. Therefore, we compared the effects of two novel small-molecule LPAR5 antagonists on LPA-induced polarization parameters of the BV-2 microglia cell line. AS2717638 is a selective piperidine-based LPAR5 antagonist (IC(50) 0.038 μM) while compound 3 is a diphenylpyrazole derivative with an IC(50) concentration of 0.7 μM in BV-2 cells. Both antagonists compromised cell viability, however, at concentrations above their IC(50) concentrations. Both inhibitors blunted LPA-induced phosphorylation of STAT1 and STAT3, p65, and c-Jun and consequently reduced the secretion of pro-inflammatory cyto-/chemokines (IL-6, TNFα, IL-1β, CXCL10, CXCL2, and CCL5) at non-toxic concentrations. Both compounds modulated the expression of intracellular (COX-2 and Arg1) and plasma membrane-located (CD40, CD86, and CD206) polarization markers yet only AS2717638 attenuated the neurotoxic potential of LPA-activated BV-2 cell-conditioned medium towards CATH.a neurons. Our findings from the present in vitro study suggest that the two LPAR5 antagonists represent valuable pharmacological tools to interfere with LPA-induced pro-inflammatory signaling cascades in microglia

Feasibility and Informative Value of Environmental Sample Collection in the National Children\u27s Vanguard Study

Background: Birth cohort studies provide the opportunity to advance understanding of the impact of environmental factors on childhood health and development through prospective collection of environmental samples. Methods: We evaluated the feasibility and informative value of the environmental sample collection methodology in the initial pilot phase of the National Children\u27s Study, a planned U.S. environmental birth cohort study. Environmental samples were collected from January 2009–September 2010 at up to three home visits: pre-pregnancy (n¼306), pregnancy (n¼807), and 6-months postnatal (n¼117). Collections included air for particulate matter r2.5 mm (PM2.5), nitrogen dioxide, ozone, volatile organic compounds (VOCs), and carbonyls; vacuum dust for allergens/endotoxin; water for VOCs, trihalomethanes (THMs), and haloacetic acids (HAAs); and wipe samples for pesticides, semi-volatile organics, and metals. We characterized feasibility using sample collection rates and times and informative value using analyte detection frequencies (DF). Results: Among the 1230 home visits, environmental sample collection rates were high across all sample types (mean¼89%); all samples except the air PM2.5 samples had collection times o30 min. Informative value was low for water VOCs (median DF¼0%) and pesticide floor wipes (median DF¼5%). Informative value was moderate for air samples (median DF¼35%) and high for water THMs and HAAs (median DF¼91% and 75%, respectively). Conclusions: Though collection of environmental samples was feasible, some samples (e.g., wipe pesticides and water VOCs) yielded limited information. These results can be used in conjunction with other study design considerations, such as target population size and hypotheses of interest, to inform the method selection of future environmental health birth cohort studies

Causality - Complexity - Consistency: Can Space-Time Be Based on Logic and Computation?

The difficulty of explaining non-local correlations in a fixed causal structure sheds new light on the old debate on whether space and time are to be seen as fundamental. Refraining from assuming space-time as given a priori has a number of consequences. First, the usual definitions of randomness depend on a causal structure and turn meaningless. So motivated, we propose an intrinsic, physically motivated measure for the randomness of a string of bits: its length minus its normalized work value, a quantity we closely relate to its Kolmogorov complexity (the length of the shortest program making a universal Turing machine output this string). We test this alternative concept of randomness for the example of non-local correlations, and we end up with a reasoning that leads to similar conclusions as in, but is conceptually more direct than, the probabilistic view since only the outcomes of measurements that can actually all be carried out together are put into relation to each other. In the same context-free spirit, we connect the logical reversibility of an evolution to the second law of thermodynamics and the arrow of time. Refining this, we end up with a speculation on the emergence of a space-time structure on bit strings in terms of data-compressibility relations. Finally, we show that logical consistency, by which we replace the abandoned causality, it strictly weaker a constraint than the latter in the multi-party case.Comment: 17 pages, 16 figures, small correction

The combinatorics of the Baer-Specker group

Denote the integers by Z and the positive integers by N. The groups Z^k (k a natural number) are discrete, and the classification up to isomorphism of their (topological) subgroups is trivial. But already for the countably infinite power Z^N of Z, the situation is different. Here the product topology is nontrivial, and the subgroups of Z^N make a rich source of examples of non-isomorphic topological groups. Z^N is the Baer-Specker group. We study subgroups of the Baer-Specker group which possess group theoretic properties analogous to properties introduced by Menger (1924), Hurewicz (1925), Rothberger (1938), and Scheepers (1996). The studied properties were introduced independently by Ko\v{c}inac and Okunev. We obtain purely combinatorial characterizations of these properties, and combine them with other techniques to solve several questions of Babinkostova, Ko\v{c}inac, and Scheepers.Comment: To appear in IJ

Finite precision measurement nullifies the Kochen-Specker theorem

Only finite precision measurements are experimentally reasonable, and they cannot distinguish a dense subset from its closure. We show that the rational vectors, which are dense in S^2, can be colored so that the contradiction with hidden variable theories provided by Kochen-Specker constructions does not obtain. Thus, in contrast to violation of the Bell inequalities, no quantum-over-classical advantage for information processing can be derived from the Kochen-Specker theorem alone.Comment: 7 pages, plain TeX; minor corrections, interpretation clarified, references update

Small-molecule inhibition of STOML3 oligomerization reverses pathological mechanical hypersensitivity

The skin is equipped with specialized mechanoreceptors that allow the perception of the slightest brush. Indeed, some mechanoreceptors can detect even nanometer-scale movements. Movement is transformed into electrical signals via the gating of mechanically activated ion channels at sensory endings in the skin. The sensitivity of Piezo mechanically gated ion channels is controlled by stomatin-like protein-3 (STOML3), which is required for normal mechanoreceptor function. Here we identify small-molecule inhibitors of STOML3 oligomerization that reversibly reduce the sensitivity of mechanically gated currents in sensory neurons and silence mechanoreceptors $\textit{in vivo}$. STOML3 inhibitors in the skin also reversibly attenuate fine touch perception in normal mice. Under pathophysiological conditions following nerve injury or diabetic neuropathy, the slightest touch can produce pain, and here STOML3 inhibitors can reverse mechanical hypersensitivity. Thus, small molecules applied locally to the skin can be used to modulate touch and may represent peripherally available drugs to treat tactile-driven pain following neuropathy.This study was funded by DFG collaborative research grant SFB958 (projects A09 to K.P. and G.R.L., A01 to V.H. and Z02 to J.S.). Additional support was provided by a senior ERC grant (grant number 294678 to G.R.L.) and by the NeuroCure Cluster of Excellence (to V.H., G.R.L. and J.F.A.P.). K.P. was supported by a Cecile-Vogt Fellowship (MDC). S.P. was supported by a Marie Curie Fellowship from the European Union (grant number 253663 Touch in situ). C.P. received a Ph.D. fellowship from the University of Cagliari. J.F.A.P. was funded by a European Research Council (ERC) starting grant (ERC-2010-StG-260590), the DFG (FOR 1341, FOR 2143), the Berlin Institute of Health (BIH) and the European Union (FP7, 3x3Dimaging 323945). R.K. was supported by an ERC Advanced Investigator grant (294293-PAIN PLASTICITY). D.H. was funded by the Berlin Institute of Health (BIH). E.St.J.S., L.E. and M.M. were supported by an Alexander von Humboldt Fellowship

Lipid-soluble Vitamins A, D, and E in HIV-Infected Pregnant women in Tanzania.

There is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings. This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals. Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01). Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions

Effect of a school-based active play intervention on sedentary time and physical activity in preschool children

Early childhood is a critical time for promoting physical activity. Few studies have investigated the effect of interventions in this population. The aim of this study was to investigate the effect of a school-based active play intervention on preschool children&rsquo;s sedentary time and physical activity. Preschool children were recruited from randomly selected preschools. Schools were randomly assigned to an intervention or comparison group. One teacher per intervention school received training from active play professionals in the delivery of a 6-week active play programme. Comparison schools continued their usual practice. Children wore a uni-axial accelerometer for 7 days at baseline, immediately after and at 6-month post-intervention. No significant intervention effects were observed for sedentary time or physical activity. However, sex and hours spent at school were significant predictors of physical activity. Children who spent fewer hours (half-day children) at school were significantly more active than their full-day counterparts. Physical activity during the intervention classes was high even though neither daily physical activity nor sedentary time changed. Notably children who spent more time at preschool were less active suggesting that preschool was not as conducive to physical activity engagement as other environments

Locally harvested foods support serum 25-hydroxyvitamin D sufficiency in an indigenous population of Western Alaska

Background: Low serum vitamin D is associated with higher latitude, age, body fat percentage and low intake of fatty fish. Little documentation of vitamin D concentrations is available for Alaska Native populations. Objective: This study was undertaken to investigate serum 25-hydroxyvitamin D (25(OH)D) concentrations of the Yup'ik people of southwestern Alaska in relation to demographic and lifestyle variables, particularly with the use of locally harvested (local) foods. Design: Cross-sectional study. Methods: We estimated 25(OH)D, dietary vitamin D and calcium, percent of energy from local foods and demographic variables in 497 Yup'ik people (43% males) aged 14–92 residing in southwestern Alaska. Sampling was approximately equally divided between synthesizing and non-synthesizing seasons, although the preponderance of samples were drawn during months of increasing daylight. Results: Mean vitamin D intake was 15.1±20.2 µg/d, while local foods accounted for 22.9±17.1% of energy intake. The leading sources of vitamin D were local fish (90.1%) followed by market foods. Mean 25(OH)D concentration was 95.6±40.7 nmol/L. Participants in the upper 50th percentile of 25(OH)D concentration tended to be older, male, of lower body mass index, sampled during the synthesizing season, and among the upper 50th percentile of local food use. Conclusions: A shift away from locally harvested foods will likely increase the risk for serum 25(OH)D insufficiency in this population