Antimicrobial resistance characteristics and fitness of Gram-negative fecal bacteria from volunteers treated with minocycline or amoxicillin.

A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being bla TEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year

SuperNeurons: Dynamic GPU Memory Management for Training Deep Neural Networks

Going deeper and wider in neural architectures improves the accuracy, while the limited GPU DRAM places an undesired restriction on the network design domain. Deep Learning (DL) practitioners either need change to less desired network architectures, or nontrivially dissect a network across multiGPUs. These distract DL practitioners from concentrating on their original machine learning tasks. We present SuperNeurons: a dynamic GPU memory scheduling runtime to enable the network training far beyond the GPU DRAM capacity. SuperNeurons features 3 memory optimizations, \textit{Liveness Analysis}, \textit{Unified Tensor Pool}, and \textit{Cost-Aware Recomputation}, all together they effectively reduce the network-wide peak memory usage down to the maximal memory usage among layers. We also address the performance issues in those memory saving techniques. Given the limited GPU DRAM, SuperNeurons not only provisions the necessary memory for the training, but also dynamically allocates the memory for convolution workspaces to achieve the high performance. Evaluations against Caffe, Torch, MXNet and TensorFlow have demonstrated that SuperNeurons trains at least 3.2432 deeper network than current ones with the leading performance. Particularly, SuperNeurons can train ResNet2500 that has $10^4$ basic network layers on a 12GB K40c.Comment: PPoPP '2018: 23nd ACM SIGPLAN Symposium on Principles and Practice of Parallel Programmin

Women’s experiences of coping with the sexual side effects of antidepressant medication

A growing body of evidence has highlighted the sexual side effects of selective serotonin reuptake inhibitor (SSRI) medication. Whilst most of the research has focused on the prevalence and treatment of sexual difficulties, little is known about how patients cope with the SSRI-related sexual side effects. The objective of this study was to explore women’s experiences of coping with the sexual side effects of SSRI medication and interpretative phenomenological analysis was employed for an in-depth exploratory study of a sample of 10 women. Four broad themes emerged which are discussed under the following headings: searching, suffering in silence, trying to resolve and accepting what is. The themes provide an insight into the different strategies used by women to cope with the sexual side effects of SSRI medication and highlight the importance of contextualising these difficulties as part of an overall approach to improve the management and treatment of SSRI-related sexual side effects

From Goldilocks to Twin Peaks: multiple optimal regimes for quantum transport in disordered networks

Understanding energy transport in quantum systems is crucial for an understanding of light-harvesting in nature, and for the creation of new quantum technologies. Open quantum systems theory has been successfully applied to predict the existence of environmental noise-assisted quantum transport (ENAQT) as a widespread phenomenon occurring in biological and artificial systems. That work has been primarily focused on several `canonical' structures, from simple chains, rings and crystals of varying dimensions, to well-studied light-harvesting complexes. Studying those particular systems has produced specific assumptions about ENAQT, including the notion of a single, ideal, range of environmental coupling rates that improve energy transport. In this paper we show that a consistent subset of physically modelled transport networks can have at least two ENAQT peaks in their steady state transport efficiency.Comment: Accepted Manuscript, 11 pages, 16 figure

Διερεύνηση και μοντελοποίηση για τη μελέτη ναυτικών ατυχημάτων σε πλοία τύπου LNG

In three grazing experiments in the seasonally dry tropics of Australia, growing steers (Experiment 1), first-calf cows (Experiment 2) and mature breeder cows (Experiment 3), ingested diets for 12-17 months, which were either adequate or severely deficient in phosphorus (P) (Padeq and Pdefic, respectively). Bone mineral density (BMD) at the proximal end of the ninth coccygeal vertebra (Cy9) was measured at intervals using single photon absorptiometry (SPA). Liveweight (LW) and plasma inorganic phosphorus (PIP) concentrations were monitored at intervals and rib-bone cortical bone thickness (CBT) of biopsy samples was measured at the end of Experiments 1 and 3. Measurements of LW change, PIP concentrations and CBT confirmed that diet P intakes of cattle in the Padeq treatments were adequate whereas there was severe and chronic P deficiency in the Pdefic treatments. In Experiment 1 BMD in Padeq steers increased with LW and age from ∼0.25-0.27 g/cc (8 months, 200 kg LW) to ∼0.34 g/cc (32 months, 490 kg LW), whereas in Pdefic steers BMD decreased progressively to ∼0.23-0.24 g/cc. Although BMD decreased in the Pdefic steers bone volume of Cy9 (calculated from tail-bone thickness) increased, and some net bone deposition in the Cy9 continued. Rib-bone CBT and tail-bone BMD at the end of Experiment 1 were closely correlated (r ≤ 0.93). In Experiment 2 BMD was initially 0.33 g/cc (∼25 months, 400 kg LW) and did not change through pregnancy and lactation in Padeq cows. However, in the Pdefic cows there was a gradual decline in BMD to ∼0.25 g/cc. There was no change in dimensions of the Cy9 so the decreases in BMD involved net demineralisation of bone. In Experiment 3 BMD was less responsive to P deficiency than in Experiments 1 and 2. Only after ∼11 months was BMD reduced (P < 0.05) in the Pdefic cows, and then only by 15%. In contrast, rib-bone CBT decreased by 30% due to P deficiency, and BMD was poorly correlated with CBT (r ≤ 0.4). The effects of animal weight, age and maturity on tailbone BMD of P-adequate animals, and the different responses to P deficiency observed in young growing steers, first-calf cows and mature breeders are discussed in relation to the use of SPA measured tail-bone BMD to diagnose P deficiency in grazing cattle

Localisation determines the optimal noise rate for quantum transport

This work was supported by EPSRC Grant No. EP/L015110/1.Environmental noise plays a key role in determining the efficiency of transport in quantum systems. However, disorder and localisation alter the impact of such noise on energy transport. To provide a deeper understanding of this relationship we perform a systematic study of the connection between eigenstate localisation and the optimal dephasing rate in 1D chains. The effects of energy gradients and disorder on chains of various lengths are evaluated and we demonstrate how optimal transport efficiency is determined by both size-independent, as well as size-dependent factors. By discussing how size-dependent influences emerge from finite size effects we establish when these effects are suppressed, and show that a simple power law captures the interplay between size-dependent and size-independent responses. Moving beyond phenomenological pure dephasing, we implement a finite temperature Bloch–Redfield model that captures detailed balance. We show that the relationship between localisation and optimal environmental coupling strength continues to apply at intermediate and high temperature but breaks down in the low temperature limit.Publisher PDFPeer reviewe

Learning Opinion Dynamics From Social Traces

Opinion dynamics - the research field dealing with how people's opinions form and evolve in a social context - traditionally uses agent-based models to validate the implications of sociological theories. These models encode the causal mechanism that drives the opinion formation process, and have the advantage of being easy to interpret. However, as they do not exploit the availability of data, their predictive power is limited. Moreover, parameter calibration and model selection are manual and difficult tasks. In this work we propose an inference mechanism for fitting a generative, agent-like model of opinion dynamics to real-world social traces. Given a set of observables (e.g., actions and interactions between agents), our model can recover the most-likely latent opinion trajectories that are compatible with the assumptions about the process dynamics. This type of model retains the benefits of agent-based ones (i.e., causal interpretation), while adding the ability to perform model selection and hypothesis testing on real data. We showcase our proposal by translating a classical agent-based model of opinion dynamics into its generative counterpart. We then design an inference algorithm based on online expectation maximization to learn the latent parameters of the model. Such algorithm can recover the latent opinion trajectories from traces generated by the classical agent-based model. In addition, it can identify the most likely set of macro parameters used to generate a data trace, thus allowing testing of sociological hypotheses. Finally, we apply our model to real-world data from Reddit to explore the long-standing question about the impact of backfire effect. Our results suggest a low prominence of the effect in Reddit's political conversation.Comment: Published at KDD202

Tubal ligation and risk of breast cancer

Although it has been demonstrated in previous studies that tubal ligation can have widespread effects on ovarian function, including a decrease in the risk of subsequent ovarian cancer, few studies have evaluated effects on breast cancer risk. In a population-based case–control study of breast cancer among women 20–54 years of age conducted in three geographic areas, previous tubal ligations were reported by 25.3% of the 2173 cases and 25.8% of the 1990 controls. Initially it appeared that tubal ligations might impart a slight reduction in risk, particularly among women undergoing the procedure at young ages (< 25 years). However, women were more likely to have had the procedure if they were black, less educated, young when they bore their first child, or multiparous. After accounting for these factors, tubal ligations were unrelated to breast cancer risk (relative risk (RR) = 1.09, 95% confidence interval (CI) 0.9–1.3), with no variation in risk by age at, interval since, or calendar year of the procedure. The relationship of tubal ligations to risk did not vary according to the presence of a number of other risk factors, including menopausal status or screening history. Furthermore, effects of tubal ligation were similar for all stages at breast cancer diagnosis. Further studies would be worthwhile given the biologic plausibility of an association. However, future investigations should include information on type of procedure performed (since this may relate to biologic effects) as well as other breast cancer risk factors. © 2000 Cancer Research Campaig