An early transition to magnetic supercriticality in star formation

Magnetic fields have an important role in the evolution of interstellar medium and star formation1,2. As the only direct probe of interstellar field strength, credible Zeeman measurements remain sparse owing to the lack of suitable Zeeman probes, particularly for cold, molecular gas3. Here we report the detection of a magnetic field of +3.8 ± 0.3 microgauss through the H I narrow self-absorption (HINSA)4,5 towards L15446,7—a well-studied prototypical prestellar core in an early transition between starless and protostellar phases8–10 characterized by a high central number density11 and a low central temperature12. A combined analysis of the Zeeman measurements of quasar H I absorption, H I emission, OH emission and HINSA reveals a coherent magnetic field from the atomic cold neutral medium (CNM) to the molecular envelope. The molecular envelope traced by the HINSA is found to be magnetically supercritical, with a field strength comparable to that of the surrounding diffuse, magnetically subcritical CNM despite a large increase in density. The reduction of the magnetic flux relative to the mass, which is necessary for star formation, thus seems to have already happened during the transition from the diffuse CNM to the molecular gas traced by the HINSA. This is earlier than envisioned in the classical picture where magnetically supercritical cores capable of collapsing into stars form out of magnetically subcritical envelopes13,14.

Nuclear Adiabatic Effects of Electron-Positron Pairs on the Dynamical Instability of Very-Massive Stars

The adiabatic effects of electron-positron pair-production on the dynamical instability of very-massive stars is investigated from stellar progenitors of carbon-oxygen cores within the range of 64 M < MCO < 133 M both with and without rotation. At a very high temperature and relatively low density; the production of electron-positron pairs in the centres of massive stars leads the adiabatic index to below 4/3. The adiabatic quantities are evaluated by constructing a model into a thermodynamically consistent electron-positron equation of state (EoS) table. It is observed that the adiabatic indices in the instability regions of the rotating models are fundamentally positive with central temperature and density. Similarly, the mass of the oxygen core within the instability region has accelerated the adiabatic indices in order to compress the star, while the mass loss and adiabatic index in the non-rotating model exponentially decay. In the rotating models, a small amount of heat is required to increase the central temperature for the end fate of the massive stars. The dynamic of most of the adiabatic quantities show a similar pattern for all the rotating models. The non-rotating model may not be suitable for inducing the instability. Many adiabatic quantities have shown great effects on the dynamical instability of the massive stars due to electron-positron pair-production in their centres. The results of this work would be useful for better understanding of the end fate of very-massive stars.

Bulk observables at 5.02 TeV using quasiparticle anisotropic hydrodynamics

We compare predictions of 3+1D quasiparticle anisotropic hydrodynamics (aHydroQP) for a large set of bulk observables with experimental data collected in 5.02 TeV Pb–Pb collisions. We make predictions for identified hadron spectra, identified hadron average transverse momentum, charged particle multiplicity as a function of pseudorapidity, the kaon-to-pion ($$K/\pi $$ K / π ) and proton-to-pion ($$p/\pi $$ p / π ) ratios, identified particle and charged particle elliptic flow, and HBT radii. We compare to data collected by the ALICE collaboration in 5.02 TeV Pb–Pb collisions. We find that, based on available data, these bulk observables are well described by aHydroQP with an assumed initial central temperature of $$T_0=630$$ T 0 = 630 MeV at $$\tau _0 = 0.25$$ τ 0 = 0.25 fm/c and a constant specific shear viscosity of $$\eta /s=0.159$$ η / s = 0.159 , which corresponds to a peak specific bulk viscosity of $$\zeta /s = 0.048$$ ζ / s = 0.048 . In particular, we find that the momentum dependence of the kaon-to-pion ($$K/\pi $$ K / π ) and proton-to-pion ($$p/\pi $$ p / π ) ratios reported recently by the ALICE collaboration are extremely well described by aHydroQP in the 0–5% centrality class.

The Effect of Giving A Warm Blanket to Changes in The Central Temperature of Postoperative Patients with Subarachnoid Block Anesthesia in RSSA Malang

Introduction: Shivering after anesthesia subarachnoid block is a common complication seen with an incidence of 40-60% after anesthesia. One of the post pharmacological shivering management is given a warm blanket. Experimental research was carried out in the Conscious Installation Room of the Central Surgical Installation of RSSA Malang. Aims: The purpose of this study was to determine the effect of providing warm blankets on changes in the central temperature of postoperative patients with subarachnoid block anesthesia. The benefits of this study are to improve the quality of care for patients with surgery, accompanied by shivering events. Methods: The research design was Quasy-Experiment with Random Sampling technique, and the sample size was 20 respondents, two groups: control and treatment. The two groups of respondents' temperature were evaluated and noted before treatment and after giving blankets every 15 minutes to 60 minutes. Result: The test results of the average temperature difference before treatment and the second 60 minutes of the two groups p = 0.0142 with α = 0.05 showed significant differences concluded that temperature changes in post-anesthesia patients subarachnoid block. Conclusions: Non-pharmacological hypothermia treatment after anesthesia subarachnoid block using an electric blanket warmer is more effective because the blanket's temperature can be maintained stable so that the heat transfer process does not decrease the temperature the blanket due to the temperature of the cold environment.

Effects of Mosquito Biology on Modeled Chikungunya Virus Invasion Potential in Florida

Arboviruses transmitted by Aedes aegypti and Aedes albopictus have been introduced to Florida on many occasions. Infrequently, these introductions lead to sporadic local transmission and, more rarely, sustained local transmission. Both mosquito species are present in Florida, with spatio-temporal variation in population composition. We developed a two-vector compartmental, deterministic model to investigate factors influencing Chikungunya virus (CHIKV) establishment. The model includes a nonlinear, temperature-dependent mosquito mortality function based on minimum mortality in a central temperature region. Latin Hypercube sampling was used to generate parameter sets used to simulate transmission dynamics, following the introduction of one infected human. The analysis was repeated for three values of the mortality function central temperature. Mean annual temperature was consistently important in the likelihood of epidemics, and epidemics increased as the central temperature increased. Ae. albopictus recruitment was influential at the lowest central temperature while Ae. aegypti recruitment was influential at higher central temperatures. Our results indicate that the likelihood of CHIKV establishment may vary, but overall Florida is permissive for introductions. Model outcomes were sensitive to the specifics of mosquito mortality. Mosquito biology parameters are variable, and improved understanding of this variation will improve our ability to predict the outcome of introductions.

Effects of Mosquito Biology on Modeled Chikungunya Virus Invasion Potential in Florida

: Arboviruses transmitted by Aedes aegypti and Ae. albopictus have been introduced to Florida on many occasions. Infrequently, these introductions lead to sporadic local transmission and, more rarely, sustained local transmission. Both mosquito species are present in Florida, with spatio-temporal variation in population composition. We developed a 2-vector compartmental, deterministic model to investigate factors influencing Chikungunya virus (CHIKV) establishment. The model includes a non-linear, temperature-dependent mosquito mortality function based on minimum mortality in a central temperature region. Latin Hypercube sampling was used to generate parameter sets used to simulate transmission dynamics, following the introduction of one infected human. The analysis was repeated for 3 values of the mortality function central temperature. Mean annual temperature was consistently important in the likelihood of epidemics, and epidemics increased as the central temperature increased. Ae. albopictus recruitment was influential at the lowest central temperature while Ae. aegypti recruitment was influential at higher central temperatures. Our results indicate that the likelihood of CHIKV establishment may vary, but overall Florida is permissive for introductions. Model outcomes were sensitive to the specifics of mosquito mortality. Mosquito biology parameters are variable, and improved understanding of this variation will improve our ability to predict the outcome of introductions.

THE PROPERTIES AND STABILITY OF SELF-GRAVITATING, POLYTROPIC SPHERES WITH γ = 1 TO 1.4 SPECIFIC HEAT RATIOS

We study self-gravitating, hydrostatic spheres with a polytropic equation of state P ∝ ρ^γ (where γ is the specific heat ratio of the gas), considering structures with γ ≈ 1 as a model for molecular cloud cores with small departures from isother- mality. We derive the properties (i.e., mass, radius and center to edge density ratio) as a function of γ for the maximal stable sphere through an application of “Bonnor’s stability criterion”. We find that in the γ = 1 → 4/3 range the mass of the maximal sphere (for a given central temperature) is almost constant, and that its radius and center to edge density ratio are growing functions of γ. We therefore have maximal stable, self-gravitating spheres with similar masses, but with increasing center to edge density contrasts for increasing departures from isothermality.

The effect of granisetron, ondansetron, and pethidine in preventing postoperative shivering: controlled clinical trial

Background: recently, use of HT35 receptor antagonists to prevent postoperative shivering has attracted a great deal of attention. Therefore, the present study was conducted with the aim of investigating the effectiveness of granisetron as an HT35 antagonist when compared with ondansetron and pethidine in preventing postoperative shivering. Methods: in this triple blind random clinical trial study, 90 patients 18-50 years of age with ASA Class I and II undergoing general anesthesia were randomly assigned into one of the three drug groups: O (4-mg ondansetron), G (40 μg/kg of granisetron), and P (25 mg pethidine), immediately before induction of anesthesia. After anesthesia induction, at the end of the surgery, after the entrance and after leaving the recovery state, central temperature, peripheral temperature, systolic blood pressure, diastolic blood pressure, heart rate, and shivering were measured and recorded. P-value less than 0.05 was considered statistically significant. Results: in the pethidine, ondansetron, and granisetron groups, 4 (13.3%), 3 (10%), and 10 (33.3%) of patients experienced shivering during recovery, where the difference between the ondansetron and granisetron groups was significant (p-value=0.02). The variations in the mean arterial pressure during the investigation stages were not significant only in the ondansetron group (p>0.05). At the beginning of recovery, the reduction of peripheral temperature was significantly lower in the ondansetron group (p<0.05), while reduction of the central temperature was higher in the granisetron group (p<0.05). By the end of the recovery, the changes in the peripheral temperature across the three groups were consistent with the changes at the beginning of recovery, but no significant difference was observed variations of the central temperature across the three groups. Conclusion: Granisetron was not found to be much effective in preventing postoperative shivering. Ondansetron and pethidine were equally effective in preventing postoperative shivering. Ondansetron also causes less hemodynamic changes compared to other drugs, while granisetron is more effective in terms of preventing nausea and vomiting

Protocolo de prevención de la hipotermia perioperatoria

La hipotermia perioperatoria es una complicación muy frecuente en nuestro medio que compromete la seguridad de nuestros pacientes quirúrgicos aumentando la morbimortalidad perioperatoria. La hipotermia también aumenta de manera considerable los costes sanitarios por el aumento de las complicaciones y la estancia hospitalaria. Recientemente se ha publicado la guía de práctica clínica de hipotermia perioperatoria no intencionada de la SEDAR. En esta guía se presenta la evidencia científica actual sobre la hipotermia perioperatoria y las recomendaciones sobre su manejo. Basado en esta guía, presentamos el protocolo de prevención de la hipotermia perioperatoria de nuestro centro con una estrategia basada en la monitorización de la temperatura central y en 3 medidas que han demostrado disminuir las complicaciones perioperatorias y ser coste-efectivas: el uso de mantas de aire convectivo, el calentamiento de los fluidos intravenosos y de irrigación, y el calentamiento activo previo a la cirugía. ABSTRACT Protocol for the prevention of perioperative hypothermia Perioperative hypothermia is a very frequent complication that compromises the safety of our surgical patients, increasing perioperative morbidity and mortality. Hypothermia also considerably increases health costs due to the increase in complications and hospital length of stay. Recently, the clinical practice guide for unintentional perioperative hypothermia of the Spanish Society of Anaesthesia (SEDAR) has been published. This guide presents current scientific evidence on perioperative hypothermia and recommendations on its management. Based on this guide, we present the protocol for the prevention of perioperative hypothermia in our institution. This protocol is based on a strategy that includes central temperature monitoring and 3 measures that have shown to reduce perioperative complications and be cost-effective: the use of convective air, warming of intravenous and irrigation fluids, and active warming prior to surgery.

Morphological Monte Carlo Simulation for Crystallization of Isotactic Polypropylene in a Temperature Gradient

Polymers are poor heat conductors, so the cooling of thick-walled shapes results in temperature gradients. Here, isotactic polypropylene (iPP) is chosen as a model polymer for the study of polymer crystallization in a temperature gradient field. The morphological Monte Carlo algorithm is applied, combined with the radius growth model, to predict the growth of spherulites. Through comparison of the two numerical solutions, analytical solution and experimental data, the validity of the morphological Monte Carlo algorithm is demonstrated. In addition, the roles of central temperature, temperature gradient for the evolution of spherulites, and the conversion degree of the melt into spherulites are considered. The results of the study show that increases in central temperature and temperature gradient can increase the anisotropy of spherulites. Isothermal crystallization and crystallization in a temperature gradient field are compared, and the differences are considered. Results show that when the central temperature is below 125 °C, and when the temperature gradients are less than 15 K/mm and 27 K/mm, the differences in the conversion degree of the melt into spherulites are less than 2% and 5%, respectively. Therefore, crystallization under such temperature gradient conditions can be simplified as isothermal crystallization.