A Molecular Perspective on Ammonia Chemistry in Atmospheric Water Droplets

Small scale chemical processes define familiar atmospheric systems such as smog, weather, and clouds. Dr. Joseph Francisco’s work uses computational chemistry to provide molecular level insights into the small scale processes that inform our understanding of the larger scale systems. We present two computational studies exploring ammonia transport and ion-pair formation at the air-water interface. These examples offer molecular perspectives on particle nucleation and ammonia cycling

Inducing and exploiting activation sparsity for fast neural network inference

Optimizing convolutional neural networks for fast inference has recently become an extremely active area of research. One of the go-to solutions in this context is weight pruning, which aims to reduce computational and memory footprint by removing large subsets of the connections in a neural network. Surprisingly, much less attention has been given to exploiting sparsity in the activation maps, which tend to be naturally sparse in many settings thanks to the structure of rectified linear (ReLU) activation functions. In this paper, we present an in-depth analysis of methods for maximizing the sparsity of the activations in a trained neural network, and show that, when coupled with an efficient sparse-input convolution algorithm, we can leverage this sparsity for significant performance gains. To induce highly sparse activation maps without accuracy loss, we introduce a new regularization technique, coupled with a new threshold-based sparsification method based on a parameterized activation function called Forced-Activation-Threshold Rectified Linear Unit (FATReLU). We examine the impact of our methods on popular image classification models, showing that most architectures can adapt to significantly sparser activation maps without any accuracy loss. Our second contribution is showing that these these compression gains can be translated into inference speedups: we provide a new algorithm to enable fast convolution operations over networks with sparse activations, and show that it can enable significant speedups for end-to-end inference on a range of popular models on the large-scale ImageNet image classification task on modern Intel CPUs, with little or no retraining cost

A Randomized, Double-Blind, Placebo-Controlled Trial of Lessertia frutescens in Healthy Adults

OBJECTIVES: Indigenous medicines are widely used throughout Africa, despite a lack of scientific evidence for their safety or efficacy. The aims of this study were: (a) to conduct a pilot study of the safety of a common indigenous South African phytotherapy, Lessertia frutescens (Sutherlandia), in healthy adults; and (b) to contribute to establishing procedures for ethical and scientifically rigorous clinical trials of African indigenous medicines. DESIGN: A randomized, double-blind, placebo-controlled trial of Sutherlandia leaf powder in healthy adults. SETTING: Tiervlei Trial Centre, Karl Bremer Hospital, Bellville, South Africa. PARTICIPANTS: 25 adults who provided informed consent and had no known significant diseases or allergic conditions nor clinically abnormal laboratory blood profiles during screening. INTERVENTION: 12 participants randomized to a treatment arm consumed 400 mg capsules of Sutherlandia leaf powder twice daily (800 mg/d). 13 individuals randomized to the control arm consumed a placebo capsule. Each participant received 180 capsules for the trial duration of 3 mo. OUTCOME MEASURES: The primary endpoint was frequency of adverse events; secondary endpoints were changes in physical, vital, blood, and biomarker indices. RESULTS: There were no significant differences in general adverse events or physical, vital, blood, and biomarker indices between the treatment and placebo groups (p > 0.05). However, participants consuming Sutherlandia reported improved appetite compared to those in the placebo group (p = 0.01). Although the treatment group exhibited a lower respiration rate (p < 0.04) and higher platelet count (p = 0.03), MCH (p = 0.01), MCHC (p = 0.02), total protein (p = 0.03), and albumin (p = 0.03), than the placebo group, these differences remained within the normal physiological range, and were not clinically relevant. The Sutherlandia biomarker canavanine was undetectable in participant plasma. CONCLUSION: Consumption of 800 mg/d Sutherlandia leaf powder capsules for 3 mo was tolerated by healthy adults

Variation within three apoptosis associated genes as potential risk factors for Achilles tendinopathy in a British based case-control cohort

Achilles tendon pathology (ATP) is a degenerative condition which exhibits excessive tenocyte apoptosis. Tumour necrosis factor receptor 1 (TNFR1), caspase-3 (CASP3) and caspase-8 (CASP8) are important regulators of apoptosis. To date, the effect of variation within the genes for TNFR1 and CASP3 as risk factors for ATP have not been described. There is evidence that two single nucleotide polymorphisms (SNPs) within the CASP8 gene are associated with ATP, but only in populations from the Southern Hemisphere. The primary aim of this study was to determine whether SNPs within the TNFRSF1A and CASP3 genes were associated with ATP in British Caucasians. We additionally sought to determine whether copy number variation (CNV) within the CASP8 gene was associated with ATP. We recruited 262 (131 ATP cases and 131 asymptomatic controls) Caucasian participants for this genetic association study and used quantitative PCR with chi-squared (χ2) tests and ANOVA to detect significant associations. We found no association between the TNFRSF1A rs4149577 (p = 0.561), CASP3 rs1049253 (p = 0.643) and CASP8 copy number variants (p = 0.219) and ATP. Likewise, when we tested potential interactions between gender, genotype and the risk of ATP, we found no association with the variants investigated. In conclusion, the TNFRSF1A, CASP3 and CASP8 gene variants were not associated with ATP in British Caucasians

Memory/effector (CD45RBlo) CD4 T cells are controlled directly by IL-10 and cause IL-22–dependent intestinal pathology

Interleukin-10 acts directly on CD45RBlo but not CD45RBhi cells to control colitis upon transfer into Rag1-deficient recipients

A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction

The developmental and physiological complexity of the auditory system is likely reflected in the underlying set of genes involved in auditory function. In humans, over 150 non-syndromic loci have been identified, and there are more than 400 human genetic syndromes with a hearing loss component. Over 100 non-syndromic hearing loss genes have been identified in mouse and human, but we remain ignorant of the full extent of the genetic landscape involved in auditory dysfunction. As part of the International Mouse Phenotyping Consortium, we undertook a hearing loss screen in a cohort of 3006 mouse knockout strains. In total, we identify 67 candidate hearing loss genes. We detect known hearing loss genes, but the vast majority, 52, of the candidate genes were novel. Our analysis reveals a large and unexplored genetic landscape involved with auditory function

The employment distribution and the creation of financial dependence

A fall in national income has varied consequences for the working population: some carry on working as normal, others become unemployed. Those excluded from work lose their main income source and must usually rely on public welfare, entering a financial dependence created endogenously as the economy adjusts. The current paper examines this induced financial dependence and its implications within a Post Keynesian model. A skewed employment distribution forces higher transfer payments than would occur if employment was distributed more evenly. The additional expenditures help to sustain profitability, so it is in the collective interest of employers and profit recipients to concentrate unemployment in a subset of the working population

Higher predation risk for insect prey at low latitudes and elevations

Biotic interactions underlie ecosystem structure and function, but predicting interaction outcomes is difficult. We tested the hypothesis that biotic interaction strength increases toward the equator, using a global experiment with model caterpillars to measure predation risk. Across an 11,660-kilometer latitudinal gradient spanning six continents, we found increasing predation toward the equator, with a parallel pattern of increasing predation toward lower elevations. Patterns across both latitude and elevation were driven by arthropod predators, with no systematic trend in attack rates by birds or mammals. These matching gradients at global and regional scales suggest consistent drivers of biotic interaction strength, a finding that needs to be integrated into general theories of herbivory, community organization, and life-history evolution

Race, Slavery, and the Expression of Sexual Violence in Louisa Picquet, The Octoroon

Historically, victims of sexual violence have rarely left written accounts of their abuse, so while sexual violence has long been associated with slavery in the United States, historians have few accounts from formerly enslaved people who experienced it first-hand. Through a close reading of the narrative of Louisa Picquet, a survivor of sexual violence in Georgia and Louisiana, this article reflects on the recovery of evidence of sexual violence under slavery through amanuensis-recorded testimony, the unintended evidence of survival within the violent archive of female slavery, and the expression of “race” as an authorial device through which to demonstrate the multigenerational nature of sexual victimhood

Basic income and the right to work: a Keynesian approach

Among the proposals for radical reform of social policy are basic income, which would pay an unconditional cash benefit to all individuals, and the right to work, which would offer guaranteed employment arranged by the state if necessary. This paper examines the macroeconomic consequences of such reform proposals. It sets up a simple Keynesian income-expenditure model that includes basic income and the right to work as alternative methods of providing social assistance, along with the more traditional approach of paying unemployment benefits. The various schemes are compared and contrasted with regard to their implications for employment, stability, distribution, efficiency and the government budget. Potential benefits of basic income or the right to work are emphasised, despite the political obstacles to implementing them