Orbital-flop transition of superfluid 3He in anisotropic silica aerogel.

Superfluid 3He is a paradigm for odd-parity Cooper pairing, ranging from neutron stars to uranium-based superconducting compounds. Recently it has been shown that 3He, imbibed in anisotropic silica aerogel with either positive or negative strain, preferentially selects either the chiral A-phase or the time-reversal-symmetric B-phase. This control over basic order parameter symmetry provides a useful model for understanding imperfect unconventional superconductors. For both phases, the orbital quantization axis is fixed by the direction of strain. Unexpectedly, at a specific temperature Tx, the orbital axis flops by 90∘, but in reverse order for A and B-phases. Aided by diffusion limited cluster aggregation simulations of anisotropic aerogel and small angle X-ray measurements, we are able to classify these aerogels as either "planar" and "nematic" concluding that the orbital-flop is caused by competition between short and long range structures in these aerogels.

Understanding the complex relationship between multidimensional poverty and depressive symptoms among young South Africans: A cross-sectional study.

BACKGROUND: We use the Global Multidimensional Poverty Index (MPI) to explore how different dimensions of poverty more directly linked to young people are associated with depressive symptoms among South African youth. METHODS: Data came from the 2017 wave of the nationally-representative National Income Dynamics Study (NIDS) in South Africa. We focused on a sample of 15-24-year-olds whose depressive symptoms were assessed using an adapted version of the 10-item Centre for Epidemiological Studies Depression Scale. We examine how individual dimensions and indicators of the MPI relate to depression, in comparison to more conventional measures, including household income, subjective social standing, overcrowding and personal assets. Cross-sectional analyses were adjusted for clustering to account for sampling design. RESULTS: The MPI index was not associated with probable depression (OR = 1.02, 95 % CI 0.81-1.29). Only lack of access to the labour market emerged as a key individual dimension associated with probable depression (OR = 5.29, 95 % CI 1.70-16.47), a relationship driven by an increased odds for those not in employment, education or training. Lack of household assets, living in an informal dwelling and lower perceived social standing were also associated with increased odds for depression. No gender differences were noted. LIMITATIONS: The study is cross-sectional and not suitable to examine the causal nature of the association between multidimensional poverty and depression. CONCLUSIONS: Poverty dimensions that measure youth's access to employment or training have a strong association with depression. Further research is needed to assess whether improved access to employment or training contributes to improving mental health among young South Africans.

Distribution of terrestrial organic material in intertidal and nearshore marine sediment due to debris flow response efforts.

We examined the distribution and processing of terrestrial organic material, derived from the disposal of material from a massive debris flow event following a major wildfire in a coastal California (USA) catchment in intertidal and nearshore subtidal marine sediments. Organic matter biomarkers, pyrogenic carbon and lignin phenols, were used to trace the distribution of terrestrial debris material in marine environments. In intertidal sediments located <1 km east of the debris deposition site, pyrogenic carbon values did not significantly change and lambda values, a lignin measure, decreased over time, indicating little lateral transport of the disposed material. In subtidal sediment, pyrogenic carbon and lambda values were greatest in 20 m water depths indicating transport and deposition of this material nearshore. An additional lignin measure indicative of degradation suggested terrestrial organic material degradation in subtidal sediment decreased with distance from shore. Terrestrial biomarkers demonstrated that the disposed material was not detected in the top 20 cm of intertidal sediment but was retained in subtidal sediment offshore of the disposal site. Results suggest coastal management should incorporate consideration of the effects of debris disposal activities on nearshore benthic communities and biogeochemical cycling.

Electric field-tunable superconductivity in alternating-twist magic-angle trilayer graphene.

Engineering moiré superlattices by twisting layers in van der Waals (vdW) heterostructures has uncovered a wide array of quantum phenomena. We constructed a vdW heterostructure that consists of three graphene layers stacked with alternating twist angles ±Î¸. At the average twist angle θ ~ 1.56°, a theoretically predicted "magic angle" for the formation of flat electron bands, we observed displacement field-tunable superconductivity with a maximum critical temperature of 2.1 kelvin. By tuning the doping level and displacement field, we found that superconducting regimes occur in conjunction with flavor polarization of moiré bands and are bounded by a van Hove singularity (vHS) at high displacement fields. Our findings display inconsistencies with a weak coupling description, suggesting that the observed moiré superconductivity has an unconventional nature.

Effect of Magnetic Impurities on Superfluid

It is known that both magnetic and nonmagnetic impurities suppress unconventional superconductivity. Here we compare their effect on the paradigm unconventional superconductor, superfluid ^{3}He, using highly dilute silica aerogel. Switching magnetic to nonmagnetic scattering in the same physical system is achieved by coating the aerogel surface with ^{4}He. We find a marginal influence on the transition temperature itself. However, we have discovered that the A phase, which breaks time reversal symmetry, is strongly influenced, while the isotropic B phase is unchanged. Importantly, this occurs only if the impurities are anisotropically distributed on a global scale.

Deep microbial analysis of multiple placentas shows no evidence for a placental microbiome.

OBJECTIVES: To resolve the controversy regarding the presence of a microbiota in the placenta. DESIGN: Classical and molecular microbiological study. SETTING: All samples were collected during caesarean section. POPULATION: A total of 28 human placentas and six murine placentas. METHODS: All 28 human placentas were checked for 16S rRNA gene amplification products. Three locations from four selected human placentas and three 'environmental controls' for each placenta were placed in seven culture media. The four selected human placentas were further analysed using Gram stain, immunohistochemistry for bacteria, electron microscopy, and TaqMan RT-qPCR. Six placentas from three SPF mice were cut into four pieces each, and further analysed for 16S rRNA gene amplification. MAIN OUTCOME MEASURES: Microbiological and molecular evidence of bacteria. RESULTS: None of the placental cultures used for the full analysis, or their environmental cultures, was positive for bacterial growth. None of the other methods showed any evidence of bacteria. Immunohistochemistry showed negligible bacterial counts. None of the murine placentas showed evidence of 16S rRNA gene amplification. CONCLUSIONS: Our results support that the fetal environment in the womb is sterile. Based on the immunohistochemistry and the limit of detection of the other methods used, if a placental microbiome exists, it is of extreme low biomass, and thus its effect on clinical phenotypes is probably minor, if it exists at all. TWEETABLE ABSTRACT: Using several microbiological and molecular methods in parallel, we found no compelling evidence of bacteria in human and mouse placentas.

Orbital-Flop Transition of Angular Momentum in a Topological Superfluid.

The direction of the orbital angular momentum of the B phase of superfluid ^{3}He can be controlled by engineering the anisotropy of the silica aerogel framework within which it is imbibed. In this work, we report our discovery of an unusual and abrupt "orbital-flop" transition of the superfluid angular momentum between orientations perpendicular and parallel to the anisotropy axis. The transition has no hysteresis, warming or cooling, as expected for a continuous thermodynamic transition, and is not the result of a competition between strain and magnetic field. This demonstrates the spontaneous reorientation of the order parameter of an unconventional BCS condensate.

Obese and overweight individuals are less sensitive to information about meal times in portion-size judgements.

BACKGROUND: Obesity is related to a tendency to discount the future. Information regarding inter-meal interval (IMI) allows meal planning. We sought to assess how obese, overweight and lean people select portion sizes based on the length of an IMI. We hypothesised that individuals with a high body mass index (BMI) would discount information about the IMI. In addition, we investigated how reduced sensitivity to IMIs relates to monetary temporal discounting. METHODS: Participants (lean, n=35; overweight, n=31; obese, n=22) selected lunchtime portion sizes in response to information about the timings of their next meal. In seven trials, the time of the IMI was systematically manipulated, ranging from 'right now' to '8 h'. Participants then completed a monetary temporal discounting task. BMI was included as a continuous measure. For each participant, we conducted a linear regression of portion size on IMI to yield a gradient that reflected reduced sensitivity to future meal timings. RESULTS: As expected, participants selected larger portion sizes in response to a long IMI. Consistent with our hypothesis, individuals with a high BMI discounted information about the IMI (ß=-3.49, P=0.015; confidence interval (CI) 6.29 to -0.70). Monetary discounting also negatively predicted BMI (ß=-8.1, P=0.003; CI=-13.43 to -2.77), but did not correlate with IMI sensitivity (P>0.05). CONCLUSIONS: These results are the first to demonstrate that temporal discounting operates in planning from one meal to the next, and is more prevalent in obese and overweight, relative to lean individuals. Participants with a high BMI discounted concerns about potential future fullness and hunger in the IMI. Our observations might begin to explain associations between obesity and irregular meal timings or help to form the basis for a targeted intervention that promotes future thinking in meal planning.

Outcomes of Full-Right-Full-Left Split Liver Transplantation in Adults in the USA: A Propensity-Score Matched Analysis.

BACKGROUND: Splitting a liver for utilization in adult/pediatric recipients has been shown to decrease mortality on the wait list without increasing the overall risk of long-term graft failure compared to a whole graft. However, splitting a single donor organ for two adult recipients, full-right-full-left split liver transplantation (FRFLSLT), to overcome organ shortage is still considered controversial. OBJECTIVE: This study assessed the outcome of FRFLSLT comparing full-right (FR) and full-left (FL) with whole liver (WL) allografts in adults (1998-2010) using UNOS standard transplant analysis and research (STAR) file. Methods: Unadjusted allograft and patient survival were estimated using Kaplan-Meier survival curves. Adjusted analyses of survival were conducted controlling for propensity for WL allograft. RESULTS: There were 83,313 cases of WL, 651 FR and 117 FL. Significant differences were evident in the unadjusted cohort between recipients who received FR and FL including donor, cold ischemic time, and days on transplant waiting list. Use of FL allograft resulted in a trend toward lower graft and patient survival compared to WL and FR, which was not statistically significant (p=0.07). In the matched cohort, FL hemiliver allograft had no detrimental effect on the allograft or patient survival after split liver transplantation when compared to FR and WL. CONCLUSION: After adjusting for donor and recipient characteristics, there was no difference in allograft or patient survival with the use of FL, FR, or WL after liver transplantation in adults. FRFLSLT is a valuable and safe option to expand the donor pool.

Human Adipose-Derived Mesenchymal Stem Cells Promote Liver Regeneration.

BACKGROUND AND AIMS: Liver regeneration (LR) is of crucial importance to patients with acute liver failure, those undergoing live donor liver transplantations or extended liver resections. Effective treatment strategies aimed at accelerating liver regeneration could offer major benefits in these patients. Due to easy accessibility, human adipose-derived mesenchymal stem cells (HADMSC) are an attractive source for regenerative medicine. Herein, we investigated the effect of HADMSC on LR in a murine model. We hypothesized that HADMSC will promote LR. METHODS: Mice were subjected to CCl4-induced acute liver failure (ALF). Animals in the experimental arm were treated with HADMSC prior to CCl4-induced ALF. Liver injury was evaluated using serum levels of alanine aminotransferase (ALT), serum interleukin-6 (IL-6), and histopathology. Liver samples were stained for a specific marker of regeneration, proliferating cell nuclear antigen (PCNA). RESULTS: Histology, serum IL-6, and ALT release revealed that HADMSC treatment attenuated liver injury compared with control animals. In addition, animals treated with HADMSC were observed to have improved survival and increased number of PCNA positive cells on histology when compared with controls. CONCLUSION: HADMSCs represent a potential therapeutic strategy to promote liver regeneration.

Anisotropic phases of superfluid

It has been shown that the relative stabilities of various superfluid states of ^{3}He can be influenced by anisotropy in a silica aerogel framework. We prepared a suite of aerogel samples compressed up to 30% for which we performed pulsed NMR on ^{3}He imbibed within the aerogel. We identified A and B phases and determined their magnetic field-temperature phase diagrams as a function of strain. From these results, we infer that the B phase is distorted by negative strain forming an anisotropic superfluid state more stable than the A phase.

Stability of superfluid 3He-B in compressed aerogel.

In recent work, it was shown that new anisotropic p-wave states of superfluid (3)He can be stabilized within high-porosity silica aerogel under uniform positive strain. In contrast, the equilibrium phase in an unstrained aerogel is the isotropic superfluid B phase. Here we report that this phase stability depends on the sign of the strain. For a negative strain of ∼ 20% achieved by compression, the B phase can be made more stable than the anisotropic A phase, resulting in a tricritical point for A, B, and normal phases with a critical field of ∼ 100 mT. From pulsed NMR measurements, we identify these phases and the orientation of the angular momentum.

Effects of biochar and other amendments on the physical properties and greenhouse gas emissions of an artificially degraded soil.

Short and long-term impacts of biochar on soil properties under field conditions are poorly understood. In addition, there is a lack of field reports of the impacts of biochar on soil physical properties, gaseous emissions and C stability, particularly in comparison with other amendments. Thus, three amendments - biochar produced from oak at 650°C, humic acid (HA) and water treatment residual - (WTR) were added to a scalped silty-loam soil @ 0.5% (w/w) in triplicated plots under soybean. Over the 4-month active growing season, all amendments significantly increased soil pH, but the effect of biochar was the greatest. Biochar significantly increased soil-C by 7%, increased sub-nanopore surface area by 15% and reduced soil bulk density by 13% compared to control. However, only WTR amendment significantly increased soil nanopore surface area by 23% relative to the control. While total cumulative CH4 and CO2 emissions were not significantly affected by any amendment, cumulative N2O emission was significantly decreased in the biochar-amended soil (by 92%) compared to control over the growing period. Considering both the total gas emissions and the C removed from the atmosphere as crop growth and C added to the soil, WTR and HA resulted in net soil C losses and biochar as a soil C gain. However, all amendments reduced the global warming potential (GWP) of the soil and biochar addition even produced a net negative GWP effect. The short observation period, low application rate and high intra-treatment variation resulted in fewer significant effects of the amendments on the physicochemical properties of the soils than one might expect indicating further possible experimentation altering these variables. However, there was clear evidence of amendment-soil interaction processes affecting both soil properties and gaseous emissions, particularly for biochar, that might lead to greater changes with additional field emplacement time.

Sparse pre-Columbian human habitation in western Amazonia.

Locally extensive pre-Columbian human occupation and modification occurred in the forests of the central and eastern Amazon Basin, but whether comparable impacts extend westward and into the vast terra firme (interfluvial) zones, remains unclear. We analyzed soils from 55 sites across central and western Amazonia to assess the history of human occupation. Sparse occurrences of charcoal and the lack of phytoliths from agricultural and disturbance species in the soils during pre-Columbian times indicated that human impacts on interfluvial forests were small, infrequent, and highly localized. No human artifacts or modified soils were found at any site surveyed. Riverine bluff areas also appeared less heavily occupied and disturbed than similar settings elsewhere. Our data indicate that human impacts on Amazonian forests were heterogeneous across this vast landscape.

Sorption of atrazine and ametryn by carbonatic and non-carbonatic soils of varied origin.

Sorption of two s-triazines, atrazine and ametryn, by carbonatic soils, Histosols, Spodosols and Oxisols was examined. Linear isotherms were observed and sorption coefficients (K(d)) of both compounds were significantly lower (α = 0.05) onto carbonatic soils compared to non-carbonatic soils. Furthermore, among carbonatic soil types, the marl-carbonatic soils had the lowest sorption affinities. K(d) and organic carbon content were highly correlated, suggesting predominant influence of organic carbon in the sorption of the s-triazine, except in Oxisols and Spodosols where variations suggest other factors. Upon removal of organic matter (OM) using sodium hypochlorite and hydrogen peroxide, the K(d) values were reduced by ~90%, indicating minimal contribution of mineral surfaces. Thus OM compositional differences likely explain the large variation in s-triazine sorption within and between soil orders. This study highlights the need to consider OM composition in addition to quantity when determining pesticide applications rates, particularly for carbonatic soils.

Pentoxifylline as a rescue treatment for DMD: a randomized double-blind clinical trial.

OBJECTIVE: To determine whether pentoxifylline (PTX) slows the decline of muscle strength and function in ambulatory boys with Duchenne muscular dystrophy (DMD). METHODS: This was a multicenter, randomized, double-blinded, controlled trial comparing 12 months of daily treatment with PTX or placebo in corticosteroid-treated boys with DMD using a slow-release PTX formulation (~20 mg/kg/day). The primary outcome was the change in mean total quantitative muscle testing (QMT) score. Secondary outcomes included changes in QMT subscales, manual muscle strength, pulmonary function, and timed function tests. Outcomes were compared using Student t tests and a linear mixed-effects model. Adverse events (AEs) were compared using the Fisher exact test. RESULTS: A total of 64 boys with DMD with a mean age of 9.9 ± 2.9 years were randomly assigned to PTX or placebo in 11 participating Cooperative International Neuromuscular Research Group centers. There was no significant difference between PTX and the placebo group in total QMT scores (p = 0.14) or in most of the secondary outcomes after a 12-month treatment. The use of PTX was associated with mild to moderate gastrointestinal or hematologic AEs. CONCLUSION: The addition of PTX to corticosteroid-treated boys with DMD at a moderate to late ambulatory stage of disease did not improve or halt the deterioration of muscle strength and function over a 12-month study period. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that treatment with PTX does not prevent deterioration in muscle function or strength in corticosteroid-treated boys with DMD.

A single nucleotide deletion in exon 2 produces a novel null allele, HLA-DRB1*01:33N.

A single nucleotide deletion in codon 12 of the human leukocyte antigen HLA-DRB1*01 results in a novel null allele, DRB1*01:33N.

Randomized, blinded trial of weekend vs daily prednisone in Duchenne muscular dystrophy.

OBJECTIVE: To perform a double-blind, randomized study comparing efficacy and safety of daily and weekend prednisone in boys with Duchenne muscular dystrophy (DMD). METHODS: A total of 64 boys with DMD who were between 4 and 10 years of age were randomized at 1 of 12 centers of the Cooperative International Neuromuscular Research Group. Efficacy and safety of 2 prednisone schedules (daily 0.75 mg/kg/day and weekend 10 mg/kg/wk) were evaluated over 12 months. RESULTS: Equivalence was met for weekend and daily dosing of prednisone for the primary outcomes of quantitative muscle testing (QMT) arm score and QMT leg score. Secondary strength scores for QMT elbow flexors also showed equivalence between the 2 treatment groups. Overall side effect profiles of height and weight, bone density, cataract formation, blood pressure, and behavior, analyzed at 12 months, did not differ between weekend and daily dosing of prednisone. CONCLUSIONS: Weekend dosing of prednisone is equally beneficial to the standard daily dosing of prednisone. Analysis of side effect profiles demonstrated overall tolerability of both dosing regimens. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that weekend prednisone dosing is as safe and effective as daily prednisone in preserving muscle strength and preventing body mass index increases in boys with DMD over a 12-month period.

The influence of passive stretch and NF-κB inhibitors on the morphology of dystrophic muscle fibers.

The triangularis sterni (TS) is an expiratory muscle that is passively stretched during inspiration. The magnitude of passive stretch depends upon the location of individual fibers within the TS muscle, with fibers located more caudally being stretched ∼ 5% to 10% more than fibers in the cephalad region. In the mdx mouse model for muscular dystrophy, the TS exhibits severe pathological alterations that are ameliorated by treatment with inhibitors of the NF-κB pathway. The purpose of this study was to assess the influence of passive stretch in vivo on fiber morphology in nondystrophic and mdx TS muscles, and the morphological benefits of treating mdx mice with two distinct NF-κB inhibitors, pyrrolidine dithiocarbamate (PDTC), and ursodeoxycholic acid (UDCA). Transmission electron microscopy revealed Z-line streaming, hypercontraction, and disassociation of the plasma membrane from the basal lamina in mdx fibers. In both nondystrophic and mdx TS muscles, fiber density was larger in more caudal regions. In comparison with nondystrophic TS, fibers in the mdx TS exhibited substantial reductions in diameter throughout all regions. In vivo treatment with either PDTC or UDCA tended to increase fiber diameter in the middle and decrease fiber diameter in the caudal TS, while reducing centronucleation in the middle region. These results suggest that passive stretch induces hypercontraction and plasma membrane abnormalities in dystrophic muscle, and that differences in the magnitude of passive stretch may influence fiber morphology and the actions of NF-κB inhibitors on dystrophic morphology.