FEC killed the cut-through switch

Latency penalty in Ethernet links beyond 10Gb/s is due to forward error correction (FEC) blocks. In the worst case a single-hop penalty approaches the latency of an entire cutthrough switch. Latency jitter is also introduced, making latency prediction harder, with large peak to peak variance. These factors stretch the tail of latency distribution in Rackscale systems and Data Centers, which in turn degrades performance of distributed applications. We analyse the underlying mechanisms, calculate lower bounds and propose a different approach that would reduce the penalty, allow control over latency and feedback for application level optimisation.Rudin foundation, Isaac Newton trust, Leverhulme trust, Microsoft researc

High speed adaptive rack-scale fabrics

Rack-scale systems contain thousands of densely packed con- nected components. While a data center may accommodate a fully provisioned network, rack-scale systems demand a more compact and versatile network that would even up within a heavily populated system. Unless the critical path between communicating hosts is made faster, distributed rack-scale applications cannot scale. We present adaptive rack-scale fabrics, an architecture that uses Physical Layer Primitives, coupled with a Closed Ring Control. The resulting fabric uses pre-fetching techniques, but at the physical layer of the interconnect, to optimize performance within strict power-budget limitations.This work was partly funded by Microsoft Research through its PhD Scholarship Programme, the Leverhulme Trust (ECF- 2016-289) and the the Isaac Newton Trus

From roses to bullets: the rise and decline of post-Soviet colour revolutions

The chapter explores the reasons for the colour revolutions’ successes and failures in the post-Soviet space. The article starts with an overview on the colour movement from the first stirrings to the present day. We then propose criteria that will be applied to our analysis, constructed on five variables. The factual analysis of individual countries that follows is built around these five variables

An integrated computational-experimental approach reveals Yersinia pestis genes essential across a narrow or a broad range of environmental conditions

This is the final version. Available from BMC via the DOI in this recordAvailability of data and materials: The datasets supporting the conclusions of this article are available at the NCBI GEO website https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE100226.BACKGROUND: The World Health Organization has categorized plague as a re-emerging disease and the potential for Yersinia pestis to also be used as a bioweapon makes the identification of new drug targets against this pathogen a priority. Environmental temperature is a key signal which regulates virulence of the bacterium. The bacterium normally grows outside the human host at 28 °C. Therefore, understanding the mechanisms that the bacterium used to adapt to a mammalian host at 37 °C is central to the development of vaccines or drugs for the prevention or treatment of human disease. RESULTS: Using a library of over 1 million Y. pestis CO92 random mutants and transposon-directed insertion site sequencing, we identified 530 essential genes when the bacteria were cultured at 28 °C. When the library of mutants was subsequently cultured at 37 °C we identified 19 genes that were essential at 37 °C but not at 28 °C, including genes which encode proteins that play a role in enabling functioning of the type III secretion and in DNA replication and maintenance. Using genome-scale metabolic network reconstruction we showed that growth conditions profoundly influence the physiology of the bacterium, and by combining computational and experimental approaches we were able to identify 54 genes that are essential under a broad range of conditions. CONCLUSIONS: Using an integrated computational-experimental approach we identify genes which are required for growth at 37 °C and under a broad range of environments may be the best targets for the development of new interventions to prevent or treat plague in humans.This work was funded by the Defence Science and Technology Laboratory, award DSTLX-1000060221 (WP1)

Prevalence of Psychotic Symptoms and Their Risk Factors in Urban Tanzania

This study aimed to determine the prevalence of psychotic symptoms in urban Tanzania and their relationship with demographic, socio-economic and social factors. A random sample of 899 adults aged 15–59 was surveyed. The main outcome measure was endorsement of one or more psychotic symptoms identified by the Psychosis Screening Questionnaire. 3.9% respondents reported one or more psychotic symptoms in the preceding year. Significantly higher rates of symptoms were found in those who had recently experienced two or more stressful life events, those with CMD and people who had used cannabis in the preceding year

The association between delusional-like experiences, and tobacco, alcohol or cannabis use: a nationwide population-based survey

<p>Abstract</p> <p>Background</p> <p>Previous population-based studies have found that delusional-like experiences (DLE) are prevalent in the community, and are associated with a wide range of mental health disorders including substance use. The aim of the study was to explore the association between DLE and three commonly used substances - tobacco, alcohol and cannabis.</p> <p>Methods</p> <p>Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007. The Composite International Diagnostic Interview was used to identify DLE, common psychiatric disorders, and substance use. We examined the relationship between the variables of interest using logistic regression, adjusting for potential confounding factors.</p> <p>Results</p> <p>Of 8 773 participants, 8.4% (n = 776) subjects endorsed one or more DLE. With respect to tobacco use, compared to nonusers, DLE were more common in those who (a) had daily use, (b) commenced usage aged 15 years or less, and (c) those who smoked heavily (23 or more cigarettes per day). Participants with cannabis use disorders were more likely to endorse DLE; this association was most prominent in those with an onset of 16 years or younger. In contrast, the pattern of association between DLE versus alcohol use or dependence was less consistent, however those with early onset alcohol use disorders were more likely to endorse DLE probe items.</p> <p>Conclusions</p> <p>While cannabis use disorders have been previously linked with DLE, our findings linking alcohol and tobacco use and DLE suggest that the influence of these substances on psychosis-related outcomes warrants closer scrutiny in longitudinal prospective studies.</p

An assessment of the levels of phthalate esters and metals in the Muledane open dump, Thohoyandou, Limpopo Province, South Africa

<p>Abstract</p> <p>Background</p> <p>This work reports the determination of the levels of phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diethyl hexyl phthalate (DEHP)) and metals (lead, cadmium, manganese, zinc, iron, calcium) in composite soil samples. The soil samples were collected randomly within the Muledane open dump, Thohoyandou, Limpopo province, South Africa. Control samples were collected about 200 m away from the open dump. The phthalate esters were separated and determined by capillary gas chromatography with a flame ionization detector, whilst the metals were determined by atomic absorption spectrophotometry.</p> <p>Results</p> <p>Open dump values for the phthalate esters and metals to be generally higher in comparison to control samples for DMP, DEP, DBP and DEHP – the mean values calculated were 0.31 ± 0.12, 0.21 ± 0.05, 0.30 ± 0.07, and 0.03 ± 0.01 mg/kg, respectively, for the open dump soil samples. Nonetheless, the mean open dump values for lead, cadmium, manganese, zinc, iron and calcium were 0.07 ± 0.04, 0.003 ± 0.001, 5.02 ± 1.92, 0.31 ± 0.02, 11.62 ± 9.48 and 0.12 ± 0.13 mg/kg, respectively. The results were compared statistically.</p> <p>Conclusion</p> <p>Our results revealed that the discarding of wastes into the open dump is a potential source of soil contamination in the immediate vicinity and beyond, <it>via </it>dispersal. Increased levels of phthalate esters and metals in the soil pose a risk to public health, plants and animals. Sustained monitoring of these contaminants is recommended, in addition to upgrading the facility to a landfill.</p

Corrosion Protection Effect of Chitosan on the Performance Characteristics of A6063 Alloy

This article outlines the behaviour of water-soluble chitosan as an effective inhibitor on aluminium alloy in 3.65% NaCl at room temperature. The inhibitive ability of water-soluble chitosan was examined using electrochemical potentiodynamic polarization techniques, mass loss measurements and computational studies. The outcome of the experiment reveals that chitosan inhibited aluminium alloy in sodium chloride solution exhibits better corrosion protection than the uninhibited because chitosan nanoparticles minimize the ingression of chloride ion into the active sites of aluminium alloy by forming thin film on its surface. The losses in mass by the inhibited aluminium alloy were found to reduce as the concentration of chitosan increases. Results obtained showed that chitosan could offer inhibition efficiency above 70%. Polarization curve demonstrated that chitosan in 3.65% NaCl at room temperature acted as a mixed-type inhibitor. Adsorption of chitosan nanoparticles on the aluminium alloy was found to follow Langmuir adsorption isotherm with correlation regression coefficient (R2 ) value of 0.9961

Interaction between environmental and genetic factors modulates schizophrenic endophenotypes in the Snap-25 mouse mutant blind-drunk

To understand the pathophysiology of neuropsychiatric disorders such as schizophrenia requires consideration of multiple genetic and non-genetic factors. However, very little is known about the consequences of combining models of synaptic dysfunction with controlled environmental manipulations. Therefore, to generate new insights into gene–environment interactions and complex behaviour, we examined the influence of variable prenatal stress (PNS) on two mouse lines with mutations in synaptosomal-associated protein of 25 kDa (Snap-25): the blind-drunk (Bdr) point mutant and heterozygous Snap-25 knockout mice. Neonatal development was analysed in addition to an assessment of adult behavioural phenotypes relevant to the psychotic, cognitive and negative aspects of schizophrenia. These data show that PNS influenced specific anxiety-related behaviour in all animals. In addition, sensorimotor gating deficits previously noted in Bdr mutants were markedly enhanced by PNS; significantly, these effects could be reversed with the application of anti-psychotic drugs. Moreover, social interaction abnormalities were observed only in Bdr animals from stressed dams but not in wild-type littermates or mutants from non-stressed mothers. These results show for the first time that combining a synaptic mouse point mutant with a controlled prenatal stressor paradigm produces both modified and previously unseen phenotypes, generating new insights into the interactions between genetics and the environment relevant to the study of psychiatric disease

Nano Random Forests to mine protein complexes and their relationships in quantitative proteomics data

Ever-increasing numbers of quantitative proteomics data sets constitute an underexploited resource for investigating protein function. Multiprotein complexes often follow consistent trends in these experiments, which could provide insights about their biology. Yet, as more experiments are considered, a complex’s signature may become conditional and less identifiable. Previously we successfully distinguished the general proteomic signature of genuine chromosomal proteins from hitchhikers using the Random Forests (RF) machine learning algorithm. Here we test whether small protein complexes can define distinguishable signatures of their own, despite the assumption that machine learning needs large training sets. We show, with simulated and real proteomics data, that RF can detect small protein complexes and relationships between them. We identify several complexes in quantitative proteomics results of wild-type and knockout mitotic chromosomes. Other proteins covary strongly with these complexes, suggesting novel functional links for later study. Integrating the RF analysis for several complexes reveals known interdependences among kinetochore subunits and a novel dependence between the inner kinetochore and condensin. Ribosomal proteins, although identified, remained independent of kinetochore subcomplexes. Together these results show that this complex-oriented RF (NanoRF) approach can integrate proteomics data to uncover subtle protein relationships. Our NanoRF pipeline is available online