Generalized Wilson Chain for solving multichannel quantum impurity problems

The Numerical Renormalization Group is used to solve quantum impurity problems, which describe magnetic impurities in metals, nanodevices, and correlated materials within DMFT. Here we present a simple generalization of the Wilson Chain, which improves the scaling of computational cost with the number of channels/bands, bringing new problems within reach. The method is applied to calculate the t-matrix of the three-channel Kondo model at T=0, which shows universal crossovers near non-Fermi liquid critical points. A non-integrable three-impurity problem with three bands is also studied, revealing a rich phase diagram and novel screening/overscreening mechanisms.Comment: 5 pages + 5 pages supplementary materia

Rapid-Acting Antidepressants and Underlying Mechanisms

Loss of glial cells with resulting atrophy of the medial prefrontal cortex (mPFC) as well as the hippocampal area is demonstrated in depressed patients by brain imaging and postmortem studies. The mPFC is the master control of mood and emotional response. The hippocampus is part of the limbic system, the main function of which is to regulate emotions. The mPFC depends on the hippocampus for rapid learning and memory consolidation. Unlike monoamine reuptake inhibitor antidepressants, which take 6 to 8 weeks to exert their full effects, and with 30 - 40% unresponsive rate, ketamine acts rapidly, within a couple of hours, and has higher responsive rates. It suggests that in theory, due to its rapid effect, Ketamine could well serve as a bridging remedy to lower the rate of suicidal risk before Selective serotonin re-uptake inhibitors (SSRIs) reach their full effect for long-term depression management. Yet, ketamine has long been linked with abusive potential and possible neurotoxicity if used in large doses over a prolonged period. Even though there are no collected data to prove the associated adverse effects, awareness of this negative aspect of ketamine is sufficiently widespread to propel the psychiatric community to look for other rapidly acting antidepressant alternatives. Recent studies have shown that scopolamine, the Yueju pill, and magnesium are rapid-onset antidepressants that have mechanisms comparable to that of ketamine. These rapid-acting antidepressant agents promise to be effective and safer choices for depression management in the future, providing that further studies and investigations to produce a better and fuller understanding of their effects and limitations

Primary antifungal prophylaxis for cryptococcal disease in HIV‐positive people

Background Cryptococcal disease remains one of the main causes of death in HIV‐positive people who have low cluster of differentiation 4 (CD4) cell counts. Currently, the World Health Organization (WHO) recommends screening HIV‐positive people with low CD4 counts for cryptococcal antigenaemia (CrAg), and treating those who are CrAg‐positive. This Cochrane Review examined the effects of an approach where those with low CD4 counts received regular prophylactic antifungals, such as fluconazole. Objectives To assess the efficacy and safety of antifungal drugs for the primary prevention of cryptococcal disease in adults and children who are HIV‐positive. Search methods We searched the CENTRAL, MEDLINE PubMed, Embase OVID, CINAHL EBSCOHost, WHO International Clinical Trials Registry Platform (WHO ICTRP), ClinicalTrials.gov, conference proceedings for the International AIDS Society (IAS) and Conference on Retroviruses and Opportunistic Infections (CROI), and reference lists of relevant articles up to 31 August 2017. Selection criteria Randomized controlled trials of adults and children, who are HIV‐positive with low CD4 counts, without a current or prior diagnosis of cryptococcal disease that compared any antifungal drug taken as primary prophylaxis to placebo or standard care. Data collection and analysis Two review authors independently assessed eligibility and risk of bias, and extracted and analysed data. The primary outcome was all‐cause mortality. We summarized all outcomes using risk ratios (RR) with 95% confidence intervals (CI). Where appropriate, we pooled data in meta‐analyses. We assessed the certainty of the evidence using the GRADE approach. Main results Nine trials, enrolling 5426 participants, met the inclusion criteria of this review. Six trials administered fluconazole, while three trials administered itraconazole. Antifungal prophylaxis may make little or no difference to all‐cause mortality (RR 1.07, 95% CI 0.80 to 1.43; 6 trials, 3220 participants; low‐certainty evidence). For cryptococcal specific outcomes, prophylaxis probably reduces the risk of developing cryptococcal disease (RR 0.29, 95% CI 0.17 to 0.49; 7 trials, 5000 participants; moderate‐certainty evidence), and probably reduces deaths due to cryptococcal disease (RR 0.29, 95% CI 0.11 to 0.72; 5 trials, 3813 participants; moderate‐certainty evidence). Fluconazole prophylaxis may make no clear difference to the risk of developing clinically resistant Candida disease (RR 0.93, 95% CI 0.56 to 1.56; 3 trials, 1198 participants; low‐certainty evidence); however, there may be an increased detection of fluconazole‐resistant Candida isolates from surveillance cultures (RR 1.25, 95% CI 1.00 to 1.55; 3 trials, 539 participants; low‐certainty evidence). Antifungal prophylaxis was generally well‐tolerated with probably no clear difference in the risk of discontinuation of antifungal prophylaxis compared with placebo (RR 1.01, 95% CI 0.91 to 1.13; 4 trials, 2317 participants; moderate‐certainty evidence). Antifungal prophylaxis may also make no difference to the risk of having any adverse event (RR 1.07, 95% CI 0.88 to 1.30; 4 trials, 2317 participants; low‐certainty evidence), or a serious adverse event (RR 1.08, 95% CI 0.83 to 1.41; 4 trials, 888 participants; low‐certainty evidence) when compared to placebo or standard care. Authors' conclusions Antifungal prophylaxis reduced the risk of developing and dying from cryptococcal disease. Therefore, where CrAG screening is not available, antifungal prophylaxis may be used in patients with low CD4 counts at diagnosis and who are at risk of developing cryptococcal disease

Microrollers Flow Uphill as Granular Media

Pour sand into a container and only the grains near the top surface move. The collective motion associated with the translational and rotational energy of the grains in a thin flowing layer is quickly dissipated as friction through multibody interactions. Alternatively, consider what will happen to a bed of particles if one applies a torque to each individual particle. In this paper, we demonstrate an experimental system where torque is applied at the constituent level through a rotating magnetic field in a dense bed of microrollers. The net result is the grains roll uphill, forming a heap with a negative angle of repose. Two different regimes have been identified related to the degree of mobility or fluidization of the particles in the bulk. Velocimetry of the near surface flowing layer reveals the collective motion of these responsive particles scales in a similar way to flowing bulk granular flows. A simple granular model that includes cohesion accurately predicts the apparent negative coefficient of friction. In contrast to the response of active or responsive particles that mimic thermodynamic principles, this system results in macroscopic collective behavior that has the kinematics of a purely dissipative granular system

A Simpler Method for Predicting Weight Loss in the First Year after Roux-en-Y Gastric Bypass

Factors postulated to predict weight loss after gastric bypass surgery, include race, age, gender, technique, height, and initial weight. This paper contained 1551 gastric bypass patients (85.9% female). Operations were performed by one surgeon (MLO) at community hospitals in Southern California from 1989 to 2008 with 314 being laparoscopic and 1237 open. We created the following equation: In[percent weight] = At2 − Bt, where t was the time after operation (days) and A and B are constants. Analysis was completed on R-software. The model fits with R2 value 0.93 and gives patients a realistic mean target weight with a confidence interval of 95% for the first year. Conclusion. We created a curve predicting weight loss after surgery as a percentage of initial weight. Initial weight was the single most important predictor of weight loss after surgery. Other recorded variables accounted for less than 1% of variability. Unknown factors account for the remaining 6-7%

Impact of alternative footwear on human energy expenditure

Purpose: Use of alternative footwear options such as flip-flop style sandals and minimalist athletic shoes are becoming increasingly popular footwear choices. The purpose of the investigation was to analyze the energy expenditure and oxygen consumption requirements of walking at preferred pace while wearing flip-flops, slip-on style shoes, and minimalist athletic shoes. Methods: Eighteen healthy male adults participated in this study. In addition to an initial familiarization session, participants were tested in three different footwear conditions [thong-style flip-flops (FF), Croc® slip on shoes (CROC), and Vibram Fivefingers® minimalist shoes (MIN)]. Then after a brief warm-up, participants walked a one-mile distance at their preferred pace. Immediately following completion of the one-mile walk, participants stood quietly on the treadmill for an additional period to assess excess post-exercise oxygen consumption (EPOC). Results: A repeated-measures ANOVA that the following variables did not show evidence of a significant differently value between conditions: preferred pace (p = 0.392), average oxygen consumption (p = 0.804), energy expenditure per mile (p = 0.306), or EPOC (p = 0.088). There was shown to be a significantly higher RER during exercise in CROC compared to MIN (p = 0.031) with no significant differences observed when comparing CROC to FF (p = 0.106) or FF to MIN (p = 0.827). Conclusion: Based on the results of the current study, it appears that the alternative footwear selected for evaluation do not lead to a substantial alteration of walking pace or overall EE. However, the significant difference in RER suggesting a slightly elevated exercise intensity while wearing the CROC could perhaps be related to the softer sole, influencing overall mechanical efficiency.The study was funded by a grant awarded by the Graduate Student Council at the author’s University