ALMA observations of dust polarization and molecular line emission from the Class 0 protostellar source Serpens SMM1

We present high angular resolution dust polarization and molecular line observations carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) toward the Class 0 protostar Serpens SMM1. By complementing these observations with new polarization observations from the Submillimeter Array (SMA) and archival data from the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the James Clerk Maxwell Telescopes (JCMT), we can compare the magnetic field orientations at different spatial scales. We find major changes in the magnetic field orientation between large (~0.1 pc) scales -- where the magnetic field is oriented E-W, perpendicular to the major axis of the dusty filament where SMM1 is embedded -- and the intermediate and small scales probed by CARMA (~1000 AU resolution), the SMA (~350 AU resolution), and ALMA (~140 AU resolution). The ALMA maps reveal that the redshifted lobe of the bipolar outflow is shaping the magnetic field in SMM1 on the southeast side of the source; however, on the northwestern side and elsewhere in the source, low velocity shocks may be causing the observed chaotic magnetic field pattern. High-spatial-resolution continuum and spectral-line observations also reveal a tight (~130 AU) protobinary system in SMM1-b, the eastern component of which is launching an extremely high-velocity, one-sided jet visible in both CO(2-1) and SiO(5-4); however, that jet does not appear to be shaping the magnetic field. These observations show that with the sensitivity and resolution of ALMA, we can now begin to understand the role that feedback (e.g., from protostellar outflows) plays in shaping the magnetic field in very young, star-forming sources like SMM1.Comment: 15 pages, 6 figures, 4 tables, 1 appendix. Accepted for publication in the Astrophysical Journal. Materials accessible in the online version of the (open-access) ApJ article include the FITS files used to make the ALMA image in Figure 1(d), and a full, machine-readable version of Table

Bias and temperature dependence of the 0.7 conductance anomaly in Quantum Point Contacts

The 0.7 (2e^2/h) conductance anomaly is studied in strongly confined, etched GaAs/GaAlAs quantum point contacts, by measuring the differential conductance as a function of source-drain and gate bias as well as a function of temperature. We investigate in detail how, for a given gate voltage, the differential conductance depends on the finite bias voltage and find a so-called self-gating effect, which we correct for. The 0.7 anomaly at zero bias is found to evolve smoothly into a conductance plateau at 0.85 (2e^2/h) at finite bias. Varying the gate voltage the transition between the 1.0 and the 0.85 (2e^2/h) plateaus occurs for definite bias voltages, which defines a gate voltage dependent energy difference $\Delta$. This energy difference is compared with the activation temperature T_a extracted from the experimentally observed activated behavior of the 0.7 anomaly at low bias. We find \Delta = k_B T_a which lends support to the idea that the conductance anomaly is due to transmission through two conduction channels, of which the one with its subband edge \Delta below the chemical potential becomes thermally depopulated as the temperature is increased.Comment: 9 pages (RevTex) with 9 figures (some in low resolution

THE POTENTIAL EFFECT OF MINI-TRAMPOLINE STIFFNESS ON TAKE-OFF BEHAVIOUR OF GYMNASTS – A METHODOLOGICAL STUDY

The purpose of this study was to compare two mini-trampolines with different spring constant in regard to their effect on take-off mechanics. It was expected that the softer (36 springs) trampoline would lead to a longer contact time and a higher take-off impulse. To assess reaction forces during jumps a flexible force insole was used simultaneously with the measurement of run-in velocity by timing gates. Results showed no significant differences in contact mechanics or contact time indicating that the difference between these two trampolines is only marginal. Therefore, this study provides mainly a novel measurement approach to assess the effect of equipment changes in trampolining. Future studies are warranted to assess the athlete-equipment interaction in greater detail

Sacubitril/valsartan reduces serum uric acid concentration, an independent predictor of adverse outcomes in PARADIGM-HF

Aims: Elevated serum uric acid concentration (SUA) has been associated with an increased risk of cardiovascular disease, but this may be due to unmeasured confounders. We examined the association between SUA and outcomes as well as the effect of sacubitril/valsartan on SUA in patients with heart failure with reduced ejection fraction (HFrEF) in PARADIGM-HF. Methods and results: The association between SUA and the primary composite outcome of cardiovascular death or heart failure (HF) hospitalization, its components, and all-cause mortality was examined using Cox regression analyses among 8213 patients using quintiles (Q1–Q5) of SUA adjusted for baseline prognostic variables including estimated glomerular filtration rate (eGFR), diuretic dose, and log N-terminal pro-brain natriuretic peptide. Change in SUA from baseline over 12 months was also evaluated in each treatment group. Patients in Q5 (SUA ≥8.6 mg/dL) compared with Q1 (<5.4 mg/dL) were younger (62.8 vs. 64.2 years), more often male (88.7% vs. 63.1%), had lower systolic blood pressure (119 vs. 123 mmHg), lower eGFR (57.4 vs. 76.6 mL/min/1.73 m2), and greater diuretic use. Higher SUA was associated with a higher risk of the primary outcome (adjusted hazard ratios) Q5 vs. Q1 = 1.28 [95% confidence intervals (1.09–1.50), P = 0.003], cardiovascular death [1.44 (1.11–1.77), P = 0.001], HF hospitalization [1.37 (1.11–1.70), P = 0.004], and all-cause mortality [1.36 (1.13–1.64), P = 0.001]. Compared with enalapril, sacubitril/valsartan reduced SUA by 0.24 (0.17–0.32) mg/dL over 12 months (P < 0.0001). Sacubitril/valsartan improved outcomes, irrespective of SUA concentration. Conclusion: Serum uric acid concentration was an independent predictor of worse outcomes after multivariable adjustment in patients with HFrEF. Compared with enalapril, sacubitril/valsartan reduced SUA and improved outcomes irrespective of SUA

Risk related to pre–diabetes mellitus and diabetes mellitus in heart failure with reduced ejection fraction: insights from prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure trial

Background—The prevalence of pre–diabetes mellitus and its consequences in patients with heart failure and reduced ejection fraction are not known. We investigated these in the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial. Methods and Results—We examined clinical outcomes in 8399 patients with heart failure and reduced ejection fraction according to history of diabetes mellitus and glycemic status (baseline hemoglobin A1c [HbA1c]: <6.0% [<42 mmol/mol], 6.0%–6.4% [42–47 mmol/mol; pre–diabetes mellitus], and ≥6.5% [≥48 mmol/mol; diabetes mellitus]), in Cox regression models adjusted for known predictors of poor outcome. Patients with a history of diabetes mellitus (n=2907 [35%]) had a higher risk of the primary composite outcome of heart failure hospitalization or cardiovascular mortality compared with those without a history of diabetes mellitus: adjusted hazard ratio, 1.38; 95% confidence interval, 1.25 to 1.52;P<0.001. HbA1c measurement showed that an additional 1106 (13% of total) patients had undiagnosed diabetes mellitus and 2103 (25%) had pre–diabetes mellitus. The hazard ratio for patients with undiagnosed diabetes mellitus (HbA1c, >6.5%) and known diabetes mellitus compared with those with HbA1c<6.0% was 1.39 (1.17–1.64); P<0.001 and 1.64 (1.43–1.87); P<0.001, respectively. Patients with pre–diabetes mellitus were also at higher risk (hazard ratio, 1.27 [1.10–1.47];P<0.001) compared with those with HbA1c<6.0%. The benefit of LCZ696 (sacubitril/valsartan) compared with enalapril was consistent across the range of HbA1c in the trial. Conclusions—In patients with heart failure and reduced ejection fraction, dysglycemia is common and pre–diabetes mellitus is associated with a higher risk of adverse cardiovascular outcomes (compared with patients with no diabetes mellitus and HbA1c <6.0%). LCZ696 was beneficial compared with enalapril, irrespective of glycemic status

Dementia-related adverse events in PARADIGM-HF and other trials in heart failure with reduced ejection fraction.

Aims: Inhibition of neprilysin, an enzyme degrading natriuretic and other vasoactive peptides, is beneficial in heart failure with reduced ejection fraction (HFrEF), as shown in PARADIGM-HF which compared the angiotensin receptor–neprilysin inhibitor (ARNI) sacubitril/valsartan with enalapril. As neprilysin is also one of many enzymes clearing amyloid-β peptides from the brain, there is a theoretical concern about the long-term effects of sacubitril/valsartan on cognition. Therefore, we have examined dementia-related adverse effects (AEs) in PARADIGM-HF and placed these findings in the context of other recently conducted HFrEF trials. Methods and results: In PARADIGM-HF, patients with symptomatic HFrEF were randomized to sacubitril/valsartan 97/103 mg b.i.d. or enalapril 10 mg b.i.d. in a 1:1 ratio. We systematically searched AE reports, coded using the Medical Dictionary for Regulatory Activities (MedDRA), using Standardized MedDRA Queries (SMQs) with ‘broad’ and ‘narrow’ preferred terms related to dementia. In PARADIGM-HF, 8399 patients aged 18–96 years were randomized and followed for a median of 2.25 years (up to 4.3 years). The narrow SMQ search identified 27 dementia-related AEs: 15 (0.36%) on enalapril and 12 (0.29%) on sacubitril/valsartan [hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.33–1.59]. The broad search identified 97 (2.30%) and 104 (2.48%) AEs (HR 1.01, 95% CI 0.75–1.37), respectively. The rates of dementia-related AEs in both treatment groups in PARADIGM-HF were similar to those in three other recent trials in HFrEF. Conclusion: We found no evidence that sacubitril/valsartan, compared with enalapril, increased dementia-related AEs, although longer follow-up may be necessary to detect such a signal and more sensitive tools are needed to detect lesser degrees of cognitive impairment. Further studies to address this question are warranted

VLT/NACO near-infrared imaging and spectroscopy of N88A in the SMC

We present near-infrared imaging and spectroscopic high spatial resolution observations of the SMC region N88 containing the bright, excited, extincted and compact H II region N88A of size ~ 1 pc. To investigate its stellar content and reddening, N88 was observed using spectroscopy and imagery in the JHKs- and L'-band at a spatial resolution of ~ 0.1-0.3", using the VLT UT4 equipped with the NAOS adaptive optics system. In order to attempt to establish if the origin of the infra-red (IR) excess is due to bright nebulosity, circumstellar material and/or local dust, we used Ks vs J-K colour-magnitude (CM) and JHK colour-colour (CC) diagrams, as well as L' imagery.Our IR-data reveal in the N88 area an IR-excess fraction of geq 30 per cent of the detected stars,as well as an unprecedently detailed morphology of N88A. It consists of an embedded cluster of ~3.5" (~ 1 pc) in diameter, of at least thirteen resolved stars superposed with an unusual bright continuum centered on a very bright star. The four brightest stars in this cluster lie red-ward of H-K geq 0.45 mag, and could be classified as young stellar object (YSO) candidates. Four other probable YSO candidates are also detected in N88 along a south-north bow-shaped thin H2 filament at ~ 7" east of the young central bright star. At 0.2" east of this star, a heavily embedded core is detected that could be a massive class I protostar candidate. The 2.12 mu H2 image of N88A resembles a shell of diameter ~ 3" ~ 0.9 pc) centered on the bright star. The line ratios of H2 2-1 S(1) and 1-0 S(0) relative to 1-0 S(1), as well as the presence of high v lines, are indicative of photodissociation regions, rather than shocks.Comment: 15 pages, 14 figures, accepted by Astronomy and Astrophysics, uses pdflatex, aa.cl

Spontaneous emission from large quantum dots in nanostructures: exciton-photon interaction beyond the dipole approximation

We derive a rigorous theory of the interaction between photons and spatially extended excitons confined in quantum dots in inhomogeneous photonic materials. We show that, beyond the dipole approximation, the radiative decay rate is proportional to a non-local interaction function, which describes the interaction between light and spatially extended excitons. In this regime, light and matter degrees of freedom cannot be separated and a complex interplay between the nanostructured optical environment and the exciton envelope function emerges. We illustrate this by specific examples and derive a series of important analytical relations, which are useful for applying the formalism to practical problems. In the dipole limit, the decay rate is proportional to the projected local density of optical states and we obtain the strong and weak confinement regimes as special cases.Comment: 14 pages, 4 figure

Effects of oil and oil burn residues on seabird feathers

It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified. To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil

Mind the gap: Can we explain declining male reproductive health with known antiandrogens?

This article has been made available through the Brunel Open Access Publishing Fund.Several countries have experienced rises in cryptorchidisms, hypospadias and testicular germ cell cancer. The reasons for these trends are largely unknown, but Skakkebaek has proposed that these disorders form a testicular dysgenesis syndrome and can be traced to androgen insufficiency in foetal life. This suggests that antiandrogenic chemicals might contribute to risks, but few chemicals have been linked to these diseases in epidemiological studies. In animal studies with p,p0-dichlorodiphenyldichloroethylene, effects typical of disruptions of male sexual differentiation became apparent when the foetal levels of this androgen receptor (AR) antagonist approached values associated with responses in in vitro assays. This prompted us to analyse whether the 22 chemicals with AR antagonistic properties would produce mixture effects in an in vitro AR antagonism assay when combined at concentrations found in human serum. Other antiandrogenic modalities could not be considered. Two scenarios were investigated, one representative of average serum levels reported in European countries, the other in line with levels towards the high exposures. In both situations, the in vitro potency of the 22 selected AR antagonists was too low to produce combined AR antagonistic effects at the concentrations found in human serum, although the high exposure scenario came quite close to measurable effects. Nevertheless, our analysis exposes an explanation gap which can only be bridged by conjuring up as yet undiscovered high potency AR antagonists or, alternatively, high exposures to unknown agents of average potency