New Measure of the Dissipation Region in Collisionless Magnetic Reconnection

A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron's rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation

NuSTAR discovery of an unusually steady long-term spin-up of the Be binary 2RXP J130159.6-635806

We present spectral and timing analysis of NuSTAR observations of the accreting X-ray pulsar 2RXP J130159.6-635806. The source was serendipitously observed during a campaign focused on the gamma-ray binary PSR B1259-63 and was later targeted for a dedicated observation. The spectrum has a typical shape for accreting X-ray pulsars, consisting of a simple power law with an exponential cutoff starting at ~7 keV with a folding energy of E_fold=~18 keV. There is also an indication of the presence of a 6.4 keV iron line in the spectrum at the ~3 sigma significance level. NuSTAR measurements of the pulsation period reveal that the pulsar has undergone a strong and steady spin-up for the last 20 years. The pulsed fraction is estimated to be ~80%, and is constant with energy up to 40 keV. The power density spectrum shows a break towards higher frequencies relative to the current spin period. This, together with steady persistent luminosity, points to a long-term mass accretion rate high enough to bring the pulsar out of spin equilibrium.Comment: 13 pages, 7 figures, accepted for publication in The Astrophysical Journa

Ab Initio No Core Shell Model - Recent Results and Further Prospects

There has been significant recent progress in solving the long-standing problems of how nuclear shell structure and collective motion emerge from underlying microscopic inter-nucleon interactions. We review a selection of recent significant results within the ab initio No Core Shell Model (NCSM) closely tied to three major factors enabling this progress: (1) improved nuclear interactions that accurately describe the experimental two-nucleon and three-nucleon interaction data; (2) advances in algorithms to simulate the quantum many-body problem with strong interactions; and (3) continued rapid development of high-performance computers now capable of performing $20 \times 10^{15}$ floating point operations per second. We also comment on prospects for further developments.Comment: Invited paper presented at NTSE-2014 and published online in the proceedings (see footnote on p.1

The taste of the pandemic—contemporary review on the current state of research on gustation in coronavirus disease 2019 (COVID‐19)

Subjectively perceived impairment of taste is a common and distinct symptom of coronavirus disease 2019 (COVID-19). Large meta-analyses identified this symptom in approximately 50% of cases. However, this high prevalence is not supported by blinded and validated psychophysical gustatory testing, which showed a much lower prevalence in up to 26% of patients. This discrepancy may be due to misinterpretation of impaired retronasal olfaction as gustatory dysfunction. In addition, we hypothesized that COVID-19–associated hyposmia is involved in the decrease of gustatory function, as found for hyposmia of different origin. This indirect mechanism would be based on the central-nervous mutual amplification between the chemical senses, which fails in COVID-19–associated olfactory loss. However, further research is necessary on how severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) may directly impair the gustatory pathway as well as its subjective perception

Older adult psychopathology: International comparisons of self-reports, collateral reports, and cross-informant agreement

Objectives:To conduct international comparisons of self-reports, collateral reports, and cross-informant agreement regarding older adult psychopathology.Participants:We compared self-ratings of problems (e.g. I cry a lot) and personal strengths (e.g. I like to help others) for 10,686 adults aged 60-102 years from 19 societies and collateral ratings for 7,065 of these adults from 12 societies.Measurements:Data were obtained via the Older Adult Self-Report (OASR) and the Older Adult Behavior Checklist (OABCL; Achenbach et al.2004).Results:Cronbach's alphas were.76 (OASR) and.80 (OABCL) averaged across societies. Across societies, 27 of the 30 problem items with the highest mean ratings and 28 of the 30 items with the lowest mean ratings were the same on the OASR and the OABCL. Q correlations between the means of the 0-1-2 ratings for the 113 problem items averaged across all pairs of societies yielded means of.77 (OASR) and.78 (OABCL). For the OASR and OABCL, respectively, analyses of variance (ANOVAs) yielded effect sizes (ESs) for society of 15% and 18% for Total Problems and 42% and 31% for Personal Strengths, respectively. For 5,584 cross-informant dyads in 12 societies, cross-informant correlations averaged across societies were.68 for Total Problems and.58 for Personal Strengths. Mixed-model ANOVAs yielded large effects for society on both Total Problems (ES = 17%) and Personal Strengths (ES = 36%).Conclusions:The OASR and OABCL are efficient, low-cost, easily administered mental health assessments that can be used internationally to screen for many problems and strengths. © International Psychogeriatric Association 2020

Routine delivery of artemisinin-based combination treatment at fixed health facilities reduces malaria prevalence in Tanzania: an observational study

BACKGROUND Artemisinin-based combination therapy (ACT) has been promoted as a means to reduce malaria transmission due to their ability to kill both asexual blood stages of malaria parasites, which sustain infections over long periods and the immature derived sexual stages responsible for infecting mosquitoes and onward transmission. Early studies reported a temporal association between ACT introduction and reduced malaria transmission in a number of ecological settings. However, these reports have come from areas with low to moderate malaria transmission, been confounded by the presence of other interventions or environmental changes that may have reduced malaria transmission, and have not included a comparison group without ACT. This report presents results from the first large-scale observational study to assess the impact of case management with ACT on population-level measures of malaria endemicity in an area with intense transmission where the benefits of effective infection clearance might be compromised by frequent and repeated re-infection. METHODS A pre-post observational study with a non-randomized comparison group was conducted at two sites in Tanzania. Both sites used sulphadoxine-pyrimethamine (SP) monotherapy as a first-line anti-malarial from mid-2001 through 2002. In 2003, the ACT, artesunate (AS) co-administered with SP (AS + SP), was introduced in all fixed health facilities in the intervention site, including both public and registered non-governmental facilities. Population-level prevalence of Plasmodium falciparum asexual parasitaemia and gametocytaemia were assessed using light microscopy from samples collected during representative household surveys in 2001, 2002, 2004, 2005 and 2006. FINDINGS Among 37,309 observations included in the analysis, annual asexual parasitaemia prevalence in persons of all ages ranged from 11% to 28% and gametocytaemia prevalence ranged from <1% to 2% between the two sites and across the five survey years. A multivariable logistic regression model was fitted to adjust for age, socioeconomic status, bed net use and rainfall. In the presence of consistently high coverage and efficacy of SP monotherapy and AS + SP in the comparison and intervention areas, the introduction of ACT in the intervention site was associated with a modest reduction in the adjusted asexual parasitaemia prevalence of 5 percentage-points or 23% (p < 0.0001) relative to the comparison site. Gametocytaemia prevalence did not differ significantly (p = 0.30). INTERPRETATION The introduction of ACT at fixed health facilities only modestly reduced asexual parasitaemia prevalence. ACT is effective for treatment of uncomplicated malaria and should have substantial public health impact on morbidity and mortality, but is unlikely to reduce malaria transmission substantially in much of sub-Saharan Africa where individuals are rapidly re-infected.Financial support for IMPACT-Tz came primarily from CDC, the U.S. Agency for International Development and the Wellcome Trust

Spectral and morphological analysis of the remnant of Supernova 1987A with ALMA & ATCA

We present a comprehensive spectral and morphological analysis of the remnant of Supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz ($\lambda$ 3.2 mm to 450 $\mu$m), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component ($S_{\nu}\propto\nu^{-0.73}$) and the thermal component originating from dust grains at $T\sim22$ K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localised west of the SN site, as the spectral analysis yields $-0.4\lesssim\alpha\lesssim-0.1$ across the western regions, with $\alpha\sim0$ around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.Comment: ApJ accepted. 21 pages, emulateapj. References update

Depression and anxiety symptoms are associated with prooxidant-antioxidant balance: a population-based study

Background: Depression and anxiety are significantly associated with systemic inflammation. Moreover, oxidative stress resulting from a disturbance in the prooxidant-antioxidant balance is linked to inflammation-related conditions. Therefore, depression/anxiety symptoms may also be associated with oxidative stress. Objective: To examine the association between depression/anxiety symptoms and serum prooxidant-antioxidant balance (PAB) in adults who participated in a large population-based, cross-sectional study. Methods: Serum PAB values were measured in 7,516 participants (62% females and 38% males) aged 35–65 years, enrolled in a population-based cohort study. Beck Depression and Anxiety Inventories were used to evaluate symptoms of depression and anxiety. Multinomial logistic regression was used to examine the effect of confounders on the status of serum PAB change. Results: Among men, serum PAB values were increased incrementally from 1.55±0.47 to 1.59±0.47, 1.69±0.38, and 1.68±0.38 in the no or minimal, mild, moderate and severe depression groups, respectively (P trend<0.001). Serum PAB values also increased significantly across these four corresponding groups among women [1.70±0.45, 1.73±0.44, 1.75±0.44, and 1.76±0.40, (P trend=0.005)]. About anxiety, serum PAB values increased significantly across the four groups in men (P trend=0.02) but not in women (P trend=0.2). The adjusted odds ratios for serum PAB values among men with severe depression and anxiety symptoms were 1.75 and 1.27, respectively. Moreover, the adjusted odds ratios for serum PAB values among women with severe depression and anxiety symptoms were 1.40 and 1.17, respectively. Conclusion: Symptoms of depression and anxiety appear to be associated with higher degrees of oxidative stress, expressed by higher serum PAB values