Neural maps for target range in the auditory cortex of echolocating bats

Computational brain maps as opposed to maps of receptor surfaces strongly reflect functional neuronal design principles. In echolocating bats, computational maps are established that topographically represent the distance of objects. These target range maps are derived from the temporal delay between emitted call and returning echo and constitute a regular representation of time (chronotopy). Basic features of these maps are innate, and in different bat species the map size and precision varies. An inherent advantage of target range maps is the implementation of mechanisms for lateral inhibition and excitatory feedback. Both can help to focus target ranging depending on the actual echolocation situation. However, these maps are not absolutely necessary for bat echolocation since there are bat species without cortical target-distance maps, which use alternative ensemble computation mechanisms.

Search for rare B(0)((s))→μ(+)μ(-)μ(+)μ(-) decays

A search for the decays B(0)((s))→μ(+)μ(-)μ(+)μ(-) and B(0)→μ(+)μ(-)μ(+)μ(-) is performed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: B(B(s)(0)→μ(+)μ(-)μ(+)μ(-))<1.6(1.2)×10(-8) and B(B(0)→μ(+)μ(-)μ(+)μ(-))<6.6(5.3)×10(-9) at 95% (90%) confidence level. In addition, limits are set in the context of a supersymmetric model which allows for the B((s))(0) meson to decay into a scalar (S) and pseudoscalar particle (P), where S and P have masses of 2.5 GeV/c and 214.3 MeV/c, respectively, both resonances decay into μ(+)μ(-). The branching fraction limits for these decays are B(B(s)(0)→SP)<1.6(1.2)×10(-8) and B(B(0)→SP)<6.3(5.1)×10(-9) at 95% (90%) confidence level.

Measurements of B(c)+ production and mass with the B(c)+ → J/ψπ+ decay

Measurements of B(c)(+) production and mass are performed with the decay mode B(c)(+)→J/ψπ(+) using 0.37 fb(-1) of data collected in pp collisions at √[s]=7 TeV by the LHCb experiment. The ratio of the production cross section times branching fraction between the B(c)(+)→J/ψπ(+) and the B(+)→J/ψK(+) decays is measured to be (0.68±0.10(stat)±0.03(syst)±0.05(lifetime))% for B(c)(+) and B(+) mesons with transverse momenta p(T)>4 GeV/c and pseudorapidities 2.5<η<4.5. The B(c)(+) mass is directly measured to be 6273.7±1.3(stat)±1.6(syst) MeV/c(2), and the measured mass difference with respect to the B(+) meson is M(B(c)(+))-M(B(+))=994.6±1.3(stat)±0.6(syst) MeV/c(2).

Observation of time-reversal violation in the B0 meson system

Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) or ccK(S)(0) final states (referred to as B(+) or B(-)), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B(0) → B(-) and B(-) → B(0), as a function of the time difference between the two B decays. Using 468 × 10(6) BB pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS(T)(+) = -1.37 ± 0.14(stat) ± 0.06(syst) and ΔS(T)(-) = 1.17 ± 0.18(stat) ± 0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.

Precision measurement of the B → Xs γ photon energy spectrum, branching fraction, and direct CP asymmetry A(CP)((B → X(s+d)γ)

The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B → X(s)γ plus B → X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) → BB decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B → X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B → X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.

Evidence for an excess of B→D*τ(-)ν(τ) decays

Based on the full BABAR data sample, we report improved measurements of the ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

Search for low-mass dark-sector Higgs bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb(-1) of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the standard model-dark-sector mixing angle and the dark-sector coupling constant.

Prevalence of high screen time in English youth: association with deprivation and physical activity

BACKGROUND

Physical activity (PA) and deprivation are major determinants of health. We estimated the prevalence of high screen time (ST) among English youth and examined whether deprivation mediated the relationship between ST and PA.

METHODS

It is a cross-sectional study of 6240 participants (53% boys, aged 10-15 years) enrolled in the East of England Healthy Hearts study. The participants were categorized into three groups based on daily ST: <2, 2-4 or >4 h. Participants were classified as 'active' or 'inactive' based on PA z-scores.

RESULTS

Prevalence of >2 h ST was 36%. Participants reporting <2 h daily ST were more likely to be active than those reporting 2-4 h (adjusted OR: 1.51, 95% CI: 1.26-1.82, P< 0.001) or >4 h (adjusted OR: 2.26, 95% CI: 1.91-2.67, P< 0.001). Analysis of covariance demonstrated a significant main effect for ST on PA (F = 85.7, P< 0.001) with lower PA in each ascending ST group (P< 0.001). Deprivation was not significantly associated with PA and did not mediate the relationship between ST and PA.

CONCLUSIONS

There is high prevalence of >2 h ST in English schoolchildren. PA is lower in children reporting 2-4 versus <2 h daily ST and lower still in those classified as heavy users (>4 h) independent of deprivation.

Contrasting physical activity patterns in children and adolescents living in differing environments in the UK

Aims: There is evidence for lower physical activity (PA) in rural adults; it is important to evaluate how the environment influences the PA of children and adolescents. Methods: We compared the PA of 6485 English 10—15.9 year olds according to two systems for classifying the immediate environment. System one compared urban and rural areas. System two compared urban, town and fringe, and rural areas. Analyses were carried out separately for children (<13 years) and adolescents (>13 years). Results: Rural children were more active than those from urban areas (OR 1.38, 95% CI 1.15—1.66) as were adolescents (OR 1.30, 95% CI 1.11—1.51). Using trilateral division, children were more active if they lived in town and fringe (OR 1.32, 95% CI 1.03—1.67) or rural (OR 1.45, 95% CI 1.14—1.84) areas compared with urban areas. Adolescents from town and fringe areas were more active than urban dwellers (OR 1.50, 95% CI 1.24—1.81). Rural adolescents’ PA did not differ from urban dwellers’. Conclusions: Rural environments support PA in children but not that of adolescents. Town and fringe areas with mixed elements of rural and urban land use appear to facilitate and sustain PA in both children and adolescents.

Plant ribosome-inactivating proteins type II induce the unfolded protein response in human cancer cells

Cytotoxic ribosome-inactivating proteins (RIPs) of type II such as ricin were investigated as anti-cancer agents, but also pose a threat as biological weapons. The molecular mechanism leading to their toxic effects is, however, not yet clear. The current paradigm, which states that the irreversible depurination of 28S rRNA results in a general translational arrest eventually leading to cell death, has been questioned. Using micro-array, qRT-PCR and Western blot, we identified the unfolded protein response (UPR), a cellular mechanism activated in response to endoplasmic reticulum stress, that is induced in HCT116 and MDA-MB-231 cells exposed to the plant type II RIPs ricin, riproximin and volkensin. Apoptosis was induced by concentrations at which translation of UPR-related genes still occurred, despite concomitant ribosomal depurination. We conclude that UPR induction represents a model that better describes the cellular effects of RIP exposure at concentrations at which selected proteins are translated despite ribosomal depurination.

Handgrip strength in English schoolchildren

AIMS

The aims of this study were to evaluate patterns of handgrip (HG) strength in relation to gender and age in English schoolchildren and to compare this with existing data and produce reference data for this population.

METHODS

The HG of 7147 English schoolchildren (3773 boys and 3374 girls) aged 10-15.9 years was measured using a portable Takei handgrip dynamometer (Takei Scientific Instruments Co. Ltd, Tokyo, Japan). Centile data were produced using the Generalized Additive Models for Location, Scale and Shape. Z-scores were generated using existing data for European children. Age and gender interactions were analysed using analysis of covariance.

RESULTS

In boys and girls, significant increases in HG were found between every age-group (p < 0.001). Boys were significantly stronger than girls at every age (p < 0.001) and the boys' age-related increase was significantly greater than the girls' (p < 0.001).

CONCLUSION

This study provides reference data for handgrip strength in English schoolchildren. Handgrip strength in English children is broadly similar to existing European data, after adjusting for mass and stature. These data could be used for clinical or athletic screening of low and high strength in this population.

Ten year secular declines in the cardiorespiratory fitness of affluent English children are largely independent of changes in body mass index

Secular changes in body mass index (BMI) and cardiorespiratory fitness (20 m shuttle-run test performance) were assessed in 10-year-old children from an affluent area of England in 1998 (n = 303; 158 boys and 145 girls) and 2008 (n = 315; 158 boys and 157 girls). Girls' BMI did not change over the 10 year period. There was a significant increase in boys' BMI (p = 0.02). Cardiorespiratory fitness declined significantly (p<0.001) in both boys (7%) and girls (9%). This study shows a large and worrying decline in cardiorespiratory fitness in children from an affluent area of England.

In vitro effect of vanadate on content, secretion and biosynthesis of insulin in isolated islets of normal Wistar rats

In in vitro experiments the effect of (Na-ortho)vanadate (1-50 mumol/l) on content, secretion and biosynthesis of insulin was investigated in isolated islets of normal Wistar rats. Compared with controls insulin content is unchanged, but insulin secretion and biosynthesis rate are significantly reduced; secretion is significantly more reduced in the basal than in the stimulating glucose medium. Our results support the view that vanadate exhibits its influence on insulin metabolism in the beta cell already.