Supernovae and Positron Annihilation

Radioactive nuclei, especially those created in SN explosion, have long been suggested to be important contributors of galactic positrons. In this paper we describe the findings of three independent OSSE/SMM/TGRS studies of positron annihilation radiation, demonstrating that the three studies are largely in agreement as to the distribution of galactic annihilation radiation. We then assess the predicted yields and distributions of SN-synthesized radionuclei, determining that they are marginally compatible with the findings of the annihilation radiation studies.Comment: 7 pages, accepted for publication in New Astronomy Reviews (Astronomy with Radioactivites III

Advanced Compton Telescope Designs and SN Science

The Advanced Compton Telescope (ACT) has been suggested to be the optimal next-generation instrument to study nuclear gamma-ray lines. In this work, we investigate the potential of three hypothetical designs of the ACT to perform SN science. We provide estimates of 1) the SN detection rate, 2) the SN Ia discrimination rate, and 3) which gamma-ray lines would be detected from specific supernova remnants. We find that the prompt emission from a SN Ia is such that it is unlikely that one would be within the range that an INTERMEDIATE ACT would be able to distinguish between explosion scenarios, although such an instrument would detect a handful of SNRs. We further find that the SUPERIOR ACT design would be a truly breakthrough instrument for SN science. By supplying these estimates, we intend to assist the gamma-ray astrophysics community in deciding the course of the next decade of gamma-ray SN science.Comment: 10 pages, accepted for publication in New astronomy Reviews (Astronomy with Radioactivities III

Kleene Algebras and Semimodules for Energy Problems

With the purpose of unifying a number of approaches to energy problems found in the literature, we introduce generalized energy automata. These are finite automata whose edges are labeled with energy functions that define how energy levels evolve during transitions. Uncovering a close connection between energy problems and reachability and B\"uchi acceptance for semiring-weighted automata, we show that these generalized energy problems are decidable. We also provide complexity results for important special cases

Orbital effect of in-plane magnetic field on quantum transport in chaotic lateral dots

We show how the in-plane magnetic field, which breaks time-reversal and rotational symmetries of the orbital motion of electrons in a heterostructure due to the momentum-dependent inter-subband mixing, affects weak localisation correction to conductance of a large-area chaotic lateral quantum dot and parameteric dependences of universal conductance fluctuations in it.Comment: 4 pages with a figur

Steering protein and salt ad- and desorption by an electrical switch applied to polymer-coated electrodes

Although solid-phase chromatography is a well-established method for protein separation, chemically intensive and often costly regeneration steps are needed to make reuse of the adsorbent possible. Here, we demonstrate the use of electrochemical principles as sustainable alternative. We make use of spontaneous adsorption of proteins to solid electrodes and reverse this process by applying an electric potential to regenerate the interface. This allows for adsorption of proteins to take place at 0 V difference between the electrodes, due to electrostatic interactions between the protein and the electrode surface. The desorption is then triggered by applying a potential difference (−1.2 V) between the electrodes.It is demonstrated that the incorporation of negatively charged polystyrene sulfonate (PSS) or positively charged polydiallyldimethylammonium chloride (PDMAC) in or on top of the respective activated carbon electrodes increases the amount of exchanged protein from 1 to 10 mg g−1, as compared to simple activated carbon electrodes. Interestingly, salt ad- and desorption occurs in opposite cycles compared to protein ad- and desorption, resulting in simultaneous concentration and desalting of the protein when 0 V is applied. On top of that, we also found that an enrichment in β-lactoglobulin could be achieved starting from whey protein isolate. These results clearly demonstrate that electrochemical technologies can be used not only for protein separation (including removal of salt), but also for protein fractionation, while not requiring solvent use

Learning from previous lockdown measures and minimising harmful biopsychosocial consequences as they end: A systematic review

Background Infectious outbreaks, most recently coronavirus disease 2019 (COVID-19), have required pervasive public health strategies, termed lockdown measures, including quarantine, social distancing, and closure of workplaces and educational establishments. Although evidence analysing immediate effects is expanding, repercussions following lockdown measures remain poorly understood. This systematic review aims to analyse the biopsychosocial consequences after lockdown measures end according to short, medium, and long-term impacts. Methods PubMed, Ovid MEDLINE, Embase, PsycInfo, Web of Science, and Scopus databases were searched from inception to January 12, 2021. Reference lists were manually reviewed. Eligible studies analysed biopsychosocial functioning after lockdown measures secondary to recent infectious outbreaks ended. Lockdown measures were defined as quarantine, isolation, workplace or educational closures, social or physical distancing, and national or local closure of public institutions deemed non-essential. Studies exclusively researching outcomes during lockdown measures, examined infectious participants, or analysed lockdown measures not pertaining to an infectious outbreak were excluded. Two independent reviewers extracted data and assessed bias with a third resolving discrepancies. Data was extracted from published reports with further information requested from authors where necessary. The mixed methods appraisal tool assessed study quality, languages were restricted to English, German, Italian, and French and narrative synthesis was applied. Results Of 5149 identified studies, 40 were eligible for inclusion. Psychological distress, economic repercussions, social, biological, and behavioural ramifications were observed. Short to medium-term effects comprised reactions relating to early trauma processing whereas medium to long-term repercussions manifested in maladaptive behaviours and mental health deterioration. Increased alcohol intake, stigmatisation, and economic effects were also identified consequences. High-risk groups included health care workers, children, elderly, inpatients, those with pre-existing psychiatric diagnoses, and socially isolated individuals. Conclusions Supporting vulnerable groups and offering education, workplace modifications, financial, and social assistance may mitigate negative repercussions. Establishing a rapid and comprehensive evidence base appraising the efficacy of such interventions and identifying areas for development is essential. This review was limited by study heterogeneity and lack of randomisation in available literature. Given the unprecedented nature and progression of COVID-19, the relevance of previous outcomes remains uncertain. Protocol registration PROSPERO registration CRD4202018113

Quantum electromagnetic field in a three dimensional oscillating cavity

We compute the photon creation inside a perfectly conducting, three dimensional oscillating cavity, taking the polarization of the electromagnetic field into account. As the boundary conditions for this field are both of Dirichlet and (generalized) Neumann type, we analyze as a preliminary step the dynamical Casimir effect for a scalar field satisfying generalized Neumann boundary conditions. We show that particle production is enhanced with respect to the case of Dirichlet boundary conditions. Then we consider the transverse electric and transverse magnetic polarizations of the electromagnetic field. For resonant frequencies, the total number of photons grows exponentially in time for both polarizations, the rate being greater for transverse magnetic modes.Comment: 11 pages, 1 figur