On the order of BEC transition in weakly interacting gases predicted by mean-field theory

Predictions from Hartree-Fock (HF), Popov (P), Yukalov-Yukalova (YY) and $t$-matrix approximations regarding the thermodynamics from the normal to the BEC phase in weakly interacting Bose gases are considered. By analyzing the dependence of the chemical potential $\mu$ on temperature $T$ and particle density $\rho$ we show that none of them predicts a second-order phase transition as required by symmetry-breaking general considerations. In this work we find that the isothermal compressibility $\kappa_{T}$ predicted by these theories does not diverge at criticality as expected in a true second-order phase transition. Moreover the isotherms $\mu=\mu(\rho,T)$ typically exhibit a non-singled valued behavior in the vicinity of the BEC transition, a feature forbidden by general thermodynamic principles. This behavior can be avoided if a first order phase transition is appealed. The facts described above show that although these mean field approximations give correct results near zero temperature they are endowed with thermodynamic anomalies in the vicinity of the BEC transition. We address the implications of these results in the interpretation of current experiments with ultracold trapped alkali gases.Comment: 16 pages, 5 figure

Lineage A betacoronavirus NS2 proteins and the homologous torovirus Berne pp1a carboxy-terminal domain are phosphodiesterases that antagonize activation of RNase L

Viruses in the family Coronaviridae, within the order Nidovirales, are etiologic agents of a range of human and animal diseases, including both mild and severe respiratory diseases in humans. These viruses encode conserved replicase and structural proteins as well as more diverse accessory proteins, encoded in the 3′ ends of their genomes, that often act as host cell antagonists. We previously showed that 2′,5′-phosphodiesterases (2′,5′-PDEs) encoded by the prototypical Betacoronavirus, mouse hepatitis virus (MHV), and by Middle East respiratory syndrome-associated coronavirus antagonize the oligoadenylate-RNase L (OAS-RNase L) pathway. Here we report that additional coronavirus superfamily members, including lineage A betacoronaviruses and toroviruses infecting both humans and animals, encode 2′,5′-PDEs capable of antagonizing RNase L. We used a chimeric MHV system (MHV(Mut)) in which exogenous PDEs were expressed from an MHV backbone lacking the gene for a functional NS2 protein, the endogenous RNase L antagonist. With this system, we found that 2′,5′-PDEs encoded by the human coronavirus HCoV-OC43 (OC43; an agent of the common cold), human enteric coronavirus (HECoV), equine coronavirus (ECoV), and equine torovirus Berne (BEV) are enzymatically active, rescue replication of MHV(Mut) in bone marrow-derived macrophages, and inhibit RNase L-mediated rRNA degradation in these cells. Additionally, PDEs encoded by OC43 and BEV rescue MHV(Mut) replication and restore pathogenesis in wild-type (WT) B6 mice. This finding expands the range of viruses known to encode antagonists of the potent OAS-RNase L antiviral pathway, highlighting its importance in a range of species as well as the selective pressures exerted on viruses to antagonize it. IMPORTANCE Viruses in the family Coronaviridae include important human and animal pathogens, including the recently emerged viruses severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and Middle East respiratory syndrome-associated coronavirus (MERS-CoV). We showed previously that two viruses within the genus Betacoronavirus, mouse hepatitis virus (MHV) and MERS-CoV, encode 2′,5′-phosphodiesterases (2′,5′-PDEs) that antagonize the OAS-RNase L pathway, and we report here that these proteins are furthermore conserved among additional coronavirus superfamily members, including lineage A betacoronaviruses and toroviruses, suggesting that they may play critical roles in pathogenesis. As there are no licensed vaccines or effective antivirals against human coronaviruses and few against those infecting animals, identifying viral proteins contributing to virulence can inform therapeutic development. Thus, this work demonstrates that a potent antagonist of host antiviral defenses is encoded by multiple and diverse viruses within the family Coronaviridae, presenting a possible broad-spectrum therapeutic target

Impact of time-correlated noise on zero-noise extrapolation

Zero-noise extrapolation is a quantum error mitigation technique that has typically been studied under the ideal approximation that the noise acting on a quantum device is not time correlated. In this paper, we investigate the feasibility and performance of zero-noise extrapolation in the presence of time-correlated noise. We show that, in contrast to white noise, time-correlated noise is harder to mitigate via zero-noise extrapolation because it is difficult to scale the noise level without also modifying its spectral distribution. This limitation is particularly strong if "local"gate-level methods are applied for noise scaling. However, we find that "global"noise-scaling methods, e.g., global unitary folding, can be sufficiently reliable even in the presence of time-correlated noise

In vitro propagation of cedar (Cedrela odorata L.) from juvenile shoots

Garriga, M (Garriga, Miguel); Caligari, PDS (Caligari, Peter D. S.). Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, ChileCedrela odorata L. is one of the most important timber species currently traded in the Caribbean and Central America; however, it has been intensively exploited. In vitro techniques and clonal propagation can help to develop new plantations and assist in establishing improvement programs for this species. The aim of this study was to develop a protocol to establish in vitro conditions and to micropropagate this species from nodal explants from juvenile cuttings taken from field trees. Disinfection of node explants with 5% propiconazole CE 25 during 3 min resulted in 100% explant disinfection and 60% morphogenic response on those established explants. Shoot development was optimized by cultivating in vitro node explants in Murashige and Skoog basal medium supplemented with 2 mg L(-1) 6-bencilaminopurine and 3 mg L(-1) naphthaleneacetic acid. This medium resulted in 100% shoot development from the in vitro node explants with a 3.93 cm mean height. Rooting was also stimulated 6 wk after individualization of the regenerated plants on the same micropropagation medium with a mean of 3.9 roots per plant. In vitro plants did not show morphologic differences when compared to ex vitro seeds

Intrinsically disordered proteins access a range of hysteretic phase separation behaviors.

The phase separation behavior of intrinsically disordered proteins (IDPs) is thought of as analogous to that of polymers that undergo equilibrium lower or upper critical solution temperature (LCST and UCST, respectively) phase transition. This view, however, ignores possible nonequilibrium properties of protein assemblies. Here, by studying IDP polymers (IDPPs) composed of repeat motifs that encode LCST or UCST phase behavior, we discovered that IDPs can access a wide spectrum of nonequilibrium, hysteretic phase behaviors. Experimentally and through simulations, we show that hysteresis in IDPPs is tunable and that it emerges through increasingly stable interchain interactions in the insoluble phase. To explore the utility of hysteretic IDPPs, we engineer self-assembling nanostructures with tunable stability. These findings shine light on the rich phase separation behavior of IDPs and illustrate hysteresis as a design parameter to program nonequilibrium phase behavior in self-assembling materials

Exactly stable non-BPS spinors in heterotic string theory on tori

Considering SO(32) heterotic string theory compactified on a torus of dimension 4 and less, stability of non-supersymmetric states is studied. A non-supersymmetric state with robust stability is constructed, and its exact stability is proven in a large region of moduli space against all the possible decay mechanisms allowed by charge conservation. Using various T-duality transform matrices, we translate various selection rules about conserved charges into simpler problems resembling partition and parity of integers. For heterotic string on T^4, we give a complete list of BPS atoms with elementary excitations, and we study BPS and non-BPS molecules with various binding energies. Using string-string duality, the results are interpreted in terms of Dirichlet-branes in type IIA string theory compactified on an orbifold limit of a K3 surface.Comment: 47 pages, 14 figures, LaTe

Prevalence of Nicotine Delivery Systems by Biological Sex in the Spit for Science Study

Nicotine intake usage trends have changed over recent decades given the wide variety of nicotine delivery systems including cigarettes, vaping, hookah, and snubs/chewables. These trends also vary by demographic factors, such as race/ethnicity, sex, and socioeconomic status (SES). For example, studies in rat populations, as well as humans, have found that females tend to be more dependent on nicotine products and have a more difficult time quitting than male rats and humans (Pogun et al., 2017). Also, race/ethnicity may impact the frequency of nicotine usage in different populations; in that non-white Hispanics were more susceptible to smoking through adolescence with a peak at ages 12 and 16; whereas non-Hispanic Asian Americans were less susceptible to smoking at ages 11 and 15 (El-Toukhy et al., 2016). Certain nicotine delivery methods may be more available or perhaps more socially accepted by certain groups of people. While lower SES is associated with more prevalent cigarette advertisements and usage, individuals with a higher SES were associated with an increased prevalence of e-cigarette advertisements, leading to an increased frequency of e-cigarette usage among adolescents (Simon et al., 2018). This project aims to document rates of nicotine use across different nicotine delivery systems in college students by demographic factors. We use the Spit for Science (S4S) database to investigate prevalence rates and study if they differ by sex, race/ethnicity, or SES. It is hypothesized that higher SES individuals will have an increased frequency of use with nicotine products that are non-cigarette based, non-white Hispanics will have greater frequency with nicotine usage, and females within the study sample will display a higher dependency on nicotine products than males. Preliminary analyses reveal that there are more female participants than males throughout the S4S cohorts collected between 2020 and 2022. Across cohorts, prevalence of all nicotine delivery systems differs in female and male participants across all products. Larger differences in prevalence between females and males are observed for cigarettes, smokeless tobacco, and cigars than for products that have been introduced more recently, such as hookah, vaping, and heat-not-burn products. Further analyses will focus on patterns of use in relation to race/ethnicity and SES. Understanding nicotine usage trends within our sample could pave the way for additional research (i.e., genetic studies) and allow for the development of prevention/intervention models tailored to our sample populations.https://scholarscompass.vcu.edu/uresposters/1436/thumbnail.jp

Understanding Domestic Abuse Perpetrators: Using quantitative analysis to develop perpetrator profiles and exploring their implications for targeted intervention and risk assessment

This project set out to address the following question: Are there any common profiles of domestic abuse perpetrators in Essex, and do they present different risks and opportunities for targeted interventions? To answer this question we conducted a mixed-methods study, analysing a large, longitudinal database of domestic abuse incidents and suspect data -relating to 16,491 suspects and 40,488 observations between 2016-2020- provided by Essex Police. Our findings, presented in this executive summary, reveal at least 4 distinct clusters of domestic abuse suspects in Essex. We explore the implications of these for interventions, training, and commissioning, and make recommendations for further research