A Simultaneous Dual-Frequency Scintillation Arc Survey of Six Bright Canonical Pulsars Using the Upgraded Giant Metrewave Radio Telescope

We use the Upgraded Giant Metrewave Radio Telescope to measure scintillation arc properties in six bright canonical pulsars with simultaneous dual frequency coverage. These observations at frequencies from 300 to 750 MHz allowed for detailed analysis of arc evolution across frequency and epoch. We perform more robust determinations of arc curvature, scattering delay, and scintillation timescale frequency-dependence, and comparison between arc curvature and pseudo-curvature than allowed by single-frequency-band-per-epoch measurements, which we find to agree with theory and previous literature. We find a strong correlation between arc asymmetry and arc curvature, which we have replicated using simulations, and attribute to a bias in the Hough transform approach to scintillation arc analysis. Possible evidence for an approximately week long timescale over which a given scattering screen dominates signal propagation was found by tracking visible scintillation arcs in each epoch in PSR J1136+1551. The inclusion of a 155 minute observation allowed us to resolve the scale of scintillation variations on short timescales, which we find to be directly tied to the amount of ISM sampled over the observation. Some of our pulsars showed either consistent or emerging asymmetries in arc curvature, indicating instances of refraction across their lines of sight. Significant features in various pulsars, such as multiple scintillation arcs in PSR J1136+1551 and flat arclets in PSR J1509+5531, that have been found in previous works, were also detected. The multiple band capability of the upgraded GMRT shows excellent promise for future pulsar scintillation work

Falling Caesarean section rate and improving intra-partum outcomes: A prospective cohort study

Objective: To evaluate caesarean section (CS) rates and moderate to severe hypoxaemic ischaemic encephalopathy (HIE) rates with other core intra-partum outcomes following reconfiguration of maternity services in Cardiff, South Wales, UK. Design: Cohort study of births from 2006 to 2015. Settings: A University tertiary referral centre for foetal and maternal medicine with 6000 births/year, University Hospital of Wales, United Kingdom. Method: Data relating to births from 1 January 2006 to 31 December 2015 were extracted from the computerized maternity database on a yearly basis. Case notes of all mothers and babies for the same duration were hand searched for documentation of HIE. HIE data was also collected prospectively by neonatologist (SC) and obstetrician (PA). Main outcome measures: Incidence of caesarean section births, babies with moderate to severe HIE, instrumental vaginal births, obstetric anal sphincter injuries (OASIS) associated with instrumental delivery, and major post-partum haemorrhage (MPPH) of 2500 mL or more. Results: During this 10-year period, a downward trend in emergency CS rate was seen from 15.6% in 2006 to 10.5% in 2015, reducing total CS rate from 25.5% in 2006 to 21.2% in 2015. A downward trend in the incidence of moderate and severe HIE was seen over the same period. There was an increase in operative vaginal births (OVB) from 12.8% to 15%. The rate of spontaneous vaginal births (SVB) remained stable. The incidence of OASIS remained constant and MPPH rate has fallen. Conclusions: Following amalgamation of two medium sized obstetric units and the opening of a Midwifery Led Unit (MLU), core intrapartum outcomes have improved. Contributing factors are the introduction of regular multidisciplinary training with enhanced team working, compulsory education for obstetricians and midwives on cardiotocograph (CTG) interpretation, increased consultant presence on delivery suite, robust risk management systems and broad multidisciplinary agreement on clinical guidelines promoting vaginal birth

Palmitic Acid Analogs Exhibit Nanomolar Binding Affinity for the HIV-1 CD4 Receptor and Nanomolar Inhibition of gp120-to-CD4 Fusion

Background: We recently reported that palmitic acid (PA) is a novel and efficient CD4 fusion inhibitor to HIV-1 entry and infection. In the present report, based on in silico modeling of the novel CD4 pocket that binds PA, we describe discovery of highly potent PA analogs with increased CD4 receptor binding affinities (Kd) and gp120-to-CD4 inhibition constants (Ki). The PA analogs were selected to satisfy Lipinski’s rule of drug-likeness, increased solubility, and to avoid potential cytotoxicity. Principal Findings: PA analog 2-bromopalmitate (2-BP) was most efficacious with Kd,74 nM and Ki,122 nM, ascorbyl palmitate (6-AP) exhibited slightly higher Kd,140 nM and Ki,354 nM, and sucrose palmitate (SP) was least efficacious binding to CD4 with Kd,364 nM and inhibiting gp120-to-CD4 binding with Ki,1486 nM. Importantly, PA and its analogs specifically bound to the CD4 receptor with the one to one stoichiometry. Significance: Considering observed differences between K i and K d values indicates clear and rational direction for improving inhibition efficacy to HIV-1 entry and infection. Taken together this report introduces a novel class of natural small molecules fusion inhibitors with nanomolar efficacy of CD4 receptor binding and inhibition of HIV-1 entry

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum