Shear strength of an unsaturated silty sand

This paper presents a series of direct shear tests performed on a silty sand at three different gravimetric water contents. The soil was sampled from test pits south of Ruedlingen in North East Switzerland, where a landslide triggering experiment was carried out on a 37°-40° steep forested slope through infiltration of extreme artificial rainfall. The aim of this work was mainly to establish a correlation between the degree of saturation and slope stability. Direct shear tests were performed on reconstituted samples with a direct shear apparatus under undrained conditions for the water phase. Three of the samples were saturated after the shear phase in order to analyse the effect of wetting on shear strength. The results were interpreted with the assistance of a soil water retention curve (WRC) and an analytical slope stability analysis was performed to apply the laboratory results to the field experimen

When resources collide: Towards a theory of coincidence in information spaces

This paper is an attempt to lay out foundations for a general theory of coincidence in information spaces such as the World Wide Web, expanding on existing work on bursty structures in document streams and information cascades. We elaborate on the hypothesis that every resource that is published in an information space, enters a temporary interaction with another resource once a unique explicit or implicit reference between the two is found. This thought is motivated by Erwin Shroedingers notion of entanglement between quantum systems. We present a generic information cascade model that exploits only the temporal order of information sharing activities, combined with inherent properties of the shared information resources. The approach was applied to data from the world's largest online citizen science platform Zooniverse and we report about findings of this case study

Male Genital Allometry in Scathophagidae (Diptera)

Male genital structures are extremely divergent across species and sexual selection is largely responsible. Many sexually selected traits show positive allometry and have high phenotypic coefficients of variation (CV). Sexually-selected genital traits that come into contact with females during copula may be an exception to this general pattern. We compared the within species size allometry of the genital claspers, mandibular palps, and testes in a comparative study across the Scathophagidae. We additionally compared the levels of phenotypic variation in these traits and in hind tibia length. Within species, claspers typically displayed negative allometry and had low CV, indicative of stabilizing selection. In contrast, testis size was more like sexually selected display traits, typically being positively allometric and having very large CV. Palps tended to be positively allometric or isometric, and intermediate in levels of phenotypic variation, much like leg length. In spite of intraspecific stabilizing selection on the genital claspers, there has been major divergence of these characters across specie

Crystal structure of the human ATP-dependent splicing and export factor UAP56

Pre-mRNA splicing requires the function of a number of RNA-dependent ATPases/helicases, yet no three-dimensional structure of any spliceosomal ATPases/helicases is known. The highly conserved DECD-box protein UAP56/Sub2 is an essential splicing factor that is also important for mRNA export. The expected ATPase/helicase activity appears to be essential for the UAP56/Sub2 functions. Here, we show that purified human UAP56 is an active RNA-dependent ATPase, and we also report the crystal structures of UAP56 alone and in complex with ADP, as well as a DECD to DEAD mutant. The structures reveal a unique spatial arrangement of the two conserved helicase domains, and ADP-binding induces significant conformational changes of key residues in the ATP-binding pocket. Our structural analyses suggest a specific protein-RNA displacement model of UAP56/Sub2. The detailed structural information provides important mechanistic insights into the splicing function of UAP56/Sub2. The structures also will be useful for the analysis of other spliceosomal DExD-box ATPases/helicases

BPMN task instance streaming for efficient micro-task crowdsourcing processes

The Business Process Model and Notation (BPMN) is a standard for modeling and executing business processes with human or machine tasks. The semantics of tasks is usually discrete: a task has exactly one start event and one end event; for multi-instance tasks, all instances must complete before an end event is emitted. We propose a new task type and streaming connector for crowdsourcing able to run hundreds or thousands of micro-task instances in parallel. The two constructs provide for task streaming semantics that is new to BPMN, enable the modeling and efficient enactment of complex crowdsourcing scenarios, and are applicable also beyond the special case of crowdsourcing. We implement the necessary design and runtime support on top of Crowd- Flower, demonstrate the viability of the approach via a case study, and report on a set of runtime performance experiments

An overview of the cutaneous porphyrias

This is an overview of the cutaneous porphyrias. It is a narrative review based on the published literature and my personal experience; it is not based on a formal systematic search of the literature. The cutaneous porphyrias are a diverse group of conditions due to inherited or acquired enzyme defects in the porphyrin–haem biosynthetic pathway. All the cutaneous porphyrias can have (either as a consequence of the porphyria or as part of the cause of the porphyria) involvement of other organs as well as the skin. The single commonest cutaneous porphyria in most parts of the world is acquired porphyria cutanea tarda, which is usually due to chronic liver disease and liver iron overload. The next most common cutaneous porphyria, erythropoietic protoporphyria, is an inherited disorder in which the accumulation of bile-excreted protoporphyrin can cause gallstones and, rarely, liver disease. Some of the porphyrias that cause blistering (usually bullae) and fragility (clinically and histologically identical to porphyria cutanea tarda) can also be associated with acute neurovisceral porphyria attacks, particularly variegate porphyria and hereditary coproporphyria. Management of porphyria cutanea tarda mainly consists of visible-light photoprotection measures while awaiting the effects of treating the underlying liver disease (if possible) and treatments to reduce serum iron and porphyrin levels. In erythropoietic protoporphyria, the underlying cause can be resolved only with a bone marrow transplant (which is rarely justifiable in this condition), so management consists particularly of visible-light photoprotection and, in some countries, narrowband ultraviolet B phototherapy. Afamelanotide is a promising and newly available treatment for erythropoietic protoporphyria and has been approved in Europe since 2014

Postcopulatory Sexual Selection Is Associated with Reduced Variation in Sperm Morphology

The evolutionary role of postcopulatory sexual selection in shaping male reproductive traits, including sperm morphology, is well documented in several taxa. However, previous studies have focused almost exclusively on the influence of sperm competition on variation among species. In this study we tested the hypothesis that intraspecific variation in sperm morphology is driven by the level of postcopulatory sexual selection in passerine birds.Using two proxy measures of sperm competition level, (i) relative testes size and (ii) extrapair paternity level, we found strong evidence that intermale variation in sperm morphology is negatively associated with the degree of postcopulatory sexual selection, independently of phylogeny.Our results show that the role of postcopulatory sexual selection in the evolution of sperm morphology extends to an intraspecific level, reducing the variation towards what might be a species-specific 'optimum' sperm phenotype. This finding suggests that while postcopulatory selection is generally directional (e.g., favouring longer sperm) across avian species, it also acts as a stabilising evolutionary force within species under intense selection, resulting in reduced variation in sperm morphology traits. We discuss some potential evolutionary mechanisms for this pattern

Warming of Central European lakes and their response to the 1980s climate regime shift

Lake surface water temperatures (LSWTs) are sensitive to atmospheric warming and have previously been shown to respond to regional changes in the climate. Using a combination of in situ and simulated surface temperatures from 20 Central European lakes, with data spanning between 50 and ∼100 years, we investigate the long-term increase in annually averaged LSWT. We demonstrate that Central European lakes are warming most in spring and experience a seasonal variation in LSWT trends. We calculate significant LSWT warming during the past few decades and illustrate, using a sequential t test analysis of regime shifts, a substantial increase in annually averaged LSWT during the late 1980s, in response to an abrupt shift in the climate. Surface air temperature measurements from 122 meteorological stations situated throughout Central Europe demonstrate similar increases at this time. Climatic modification of LSWT has numerous consequences for water quality and lake ecosystems. Quantifying the response of LSWT increase to large-scale and abrupt climatic shifts is essential to understand how lakes will respond in the future

Breaking the entangling gate speed limit for trapped-ion qubits using a phase-stable standing wave

All laser-driven entangling operations for trapped-ion qubits have hitherto been performed without control of the optical phase of the light field, which precludes independent tuning of the carrier and motional coupling. By placing $^{88}$Sr$^+$ ions in a $\lambda=674$ nm standing wave, whose relative position is controlled to $\approx\lambda/100$, we suppress the carrier coupling by a factor of $18$, while coherently enhancing the spin-motion coupling. We experimentally demonstrate that the off-resonant carrier coupling imposes a speed limit for conventional traveling-wave M{\o}lmer-S{\o}rensen gates; we use the standing wave to surpass this limit and achieve a gate duration of $15\ \mu$s, restricted by the available laser power.Comment: S. Saner and O. B\u{a}z\u{a}van contributed equally to this wor

Cardiovascular mortality and exposure to extremely low frequency magnetic fields: a cohort study of Swiss railway workers

<p>Abstract</p> <p>Background</p> <p>Exposure to intermittent magnetic fields of 16 Hz has been shown to reduce heart rate variability, and decreased heart rate variability predicts cardiovascular mortality. We examined mortality from cardiovascular causes in railway workers exposed to varying degrees to intermittent 16.7 Hz magnetic fields.</p> <p>Methods</p> <p>We studied a cohort of 20,141 Swiss railway employees between 1972 and 2002, including highly exposed train drivers (median lifetime exposure 120.5 μT-years), and less or little exposed shunting yard engineers (42.1 μT-years), train attendants (13.3 μT-years) and station masters (5.7 μT-years). During 464,129 person-years of follow up, 5,413 deaths were recorded and 3,594 deaths were attributed to cardio-vascular diseases. We analyzed data using Cox proportional hazards models.</p> <p>Results</p> <p>For all cardiovascular mortality the hazard ratio compared to station masters was 0.99 (95%CI: 0.91, 1.08) in train drivers, 1.13 (95%CI: 0.98, 1.30) in shunting yard engineers, and 1.09 (95%CI: 1.00, 1.19) in train attendants.Corresponding hazard ratios for arrhythmia related deaths were 1.04 (95%CI: 0.68, 1.59), 0.58 (95%CI: 0.24, 1.37) and 1.30 (95%CI: 0.87, 1.93) and for acute myocardial infarction 1.00 (95%CI: 0.73, 1.36), 1.56 (95%CI: 1.04, 2.32), and 1.14 (95%CI: 0.85, 1.53). The hazard ratio for arrhythmia related deaths per 100 μT-years of cumulative exposure was 0.94 (95%CI: 0.71, 1.24) and 0.91 (95%CI: 0.75, 1.11) for acute myocardial infarction.</p> <p>Conclusion</p> <p>This study provides evidence against an association between long-term occupational exposure to intermittent 16.7 Hz magnetic fields and cardiovascular mortality.</p