The microscopic origin of thermal cracking in rocks: An investigation by simultaneous time-of-flight neutron diffraction and acoustic emission monitoring

We demonstrate that neutron diffraction measurements make it possible to quantify elastic strains within the interior of solid samples, and thus have great potential for addressing a wide range of problems connected with the characterization of the mechanical properties of geological materials. We use the time-of-flight neutron diffraction technique, in combination with acoustic emission monitoring, to study the evolution of thermal strain within the interior of samples of a pure quartzite during slow heating, and the onset of the associated thermal cracking. Thermal cracking commences around 180 degreesC when the thermal strain deficit along the a-axes of quartz grains induces a thermal stress that is close to the bulk tensile strength of the rock

The transient wave effect and real losses correlation-frequency, temporal, and spatial analysis

Water distribution systems are prone to transients since pumps need to be started and stopped, pumps may have sudden flow changes, human blunders can occur, equipment may fail, or other unavoidable natural events may ensue. Surge modeling techniques are available to calculate variations in pressure, under extreme or normal operating conditions, serving as a tool to predict extreme events in order to design a suitable system and, or, to aid in the implementation of proper measures to mitigate transients. However, modeling an entire water network system may not be cost effective and may require extensive research and time especially in large distribution systems. Spatial analysis may offer an efficient alternative method of uncovering areas with potential problems. In this research, spatial statistic methods were employed to find whether clustering of leak events is occurring, the distance at which the leak clustering is most prevalent, and the location of the leak concentrations. Specifically, the following spatial statistic methods were utilized: nearest neighbor, Ripley’s K-function, and the Gi* local statistic. The objective for this research was to locate stations with high concentrations of leaks and whether these leak clusters were related to pump trips due to power failures. Although the concentration of leaks was found near two stations, a correlation between the cluster of leaks and the pump trips was not established

Investigating methods for measuring face recognition under lamps of different spectral power distribution

Face recognition is one of the interpersonal judgements carried out by pedestrians. Road lighting should enhance the visual component of such judgements after dark. This paper presents experiments carried out using two different procedures, identification and perceived recognition, to investigate why earlier studies have led to inconsistent conclusions about the influence of spectral power distribution (SPD) on face recognition. For the identification procedure, two observation durations were employed (1-s and 3-s). The two procedures led to similar conclusions regarding recognition ability at different distances. Review of these and past results suggests that an effect of lamp (SPD) is more likely to be found when the task is difficult, i.e. small size, brief observation and correctly naming the target rather than simply picking a face from a sample

Smoking Gun or Circumstantial Evidence? Comparison of Statistical Learning Methods using Functional Annotations for Prioritizing Risk Variants

Although technology has triumphed in facilitating routine genome sequencing, new challenges have been created for the data-analyst. Genome-scale surveys of human variation generate volumes of data that far exceed capabilities for laboratory characterization. By incorporating functional annotations as predictors, statistical learning has been widely investigated for prioritizing genetic variants likely to be associated with complex disease. We compared three published prioritization procedures, which use different statistical learning algorithms and different predictors with regard to the quantity, type and coding. We also explored different combinations of algorithm and annotation set. As an application, we tested which methodology performed best for prioritizing variants using data from a large schizophrenia meta-analysis by the Psychiatric Genomics Consortium. Results suggest that all methods have considerable (and similar) predictive accuracies (AUCs 0.64-0.71) in test set data, but there is more variability in the application to the schizophrenia GWAS. In conclusion, a variety of algorithms and annotations seem to have a similar potential to effectively enrich true risk variants in genome-scale datasets, however none offer more than incremental improvement in prediction. We discuss how methods might be evolved for risk variant prediction to address the impending bottleneck of the new generation of genome re-sequencing studies

Fate and transport of volatile organic compounds in glacial till and groundwater at an industrial site in Northern Ireland

Volatile organic compound (VOC) contamination of subsurface geological material and groundwater was discovered on the Nortel Monkstown industrial site, Belfast, Northern Ireland. The objectives of this study were to (1) investigate the characteristics of the geological material and its influences on contaminated groundwater flow across the site using borehole logs and hydrological evaluations, and (2) identify the contaminants and examine their distribution in the subsurface geological material and groundwater using chemical analysis. This report focuses on the eastern car park (ECP) which was a former storage area associated with trichloroethene (TCE) degreasing operations. This is where the greatest amount of volatile organic compounds (VOCs), particularly TCE, were detected. The study site is on a complex deposit of clayey glacial till with discontinuous coarser grained lenses, mainly silts, sands and gravel, which occur at 0.45-7.82 m below ground level (bgl). The lenses overall form an elongated formation that acts as a small unconfined shallow aquifer. There is a continuous low permeable stiff clayey till layer beneath the lenses that performs as an aquitard to the groundwater. Highest concentrations of VOCs, mainly TCE, in the geological material and groundwater are in these coarser lenses at similar to 4.5-7 m bgl. Highest TCE measurements at 390,000 mu g L-1 for groundwater and at 39,000 mu g kg(-1) at 5.7 m for geological material were in borehole GA19 in the coarse lens zone. It is assumed that TCE gained entrance to the subsurface near this borehole where the clayey till was thin to absent above coarse lenses which provided little retardation to the vertical migration of this dense non-aqueous phase liquid (DNAPL) into the groundwater. However, TCE is present in low concentrations in the geological material overlying the coarse lens zone. Additionally, VOCs appear to be associated with poorly drained layers and in peat < 3.0 m bgl in the ECP. Some indication of natural attenuation as VOCs degradation products vinyl chloride (VC) and dichloromethane (DCM) also occur on the site

Міжнародна наукова конференція "Архівознавство як наука"

Проаналізовано внесок істориків і архівістів України в розвиток архівної науки. Вказуються основні розділи архівознавства як науки, що вимагають подальших досліджень.Проанализирован вклад историков и архивистов Украины в развитие архивной науки. Указываются основные разделы архивоведения как науки, которые требуют дальнейших исследований.A contribution of Ukrainian historians and archivists to the archival science development is covered. The basic sections of the archival science which need the further study are indicated

Skin- and gut-homing molecules on human circulating gamma delta T cells and their dysregulation in inflammatory bowel disease

Changes in phenotype and function of γδ T cells have been reported in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Dysregulation of lymphocyte migration plays a key role in IBD pathogenesis; however, data on migratory properties of γδ T cells are scarce. Human circulating γδ T cells from healthy controls (n = 27), patients with active CD (n = 15), active UC (n = 14) or cutaneous manifestations of IBD (n = 2) were characterized by flow cytometry. Circulating γδ T cells in healthy controls were CD3(hi) and expressed CD45RO. They expressed gut-homing molecule β7 but not gut-homing molecule corresponding chemokine receptors (CCR)9, or skin-homing molecules cutaneous lymphocyte-associated antigen (CLA) and CCR4, despite conventional T cells containing populations expressing these molecules. CCR9 expression was increased on γδ T cells in CD and UC, while skin-homing CLA was expressed aberrantly on γδ T cells in patients with cutaneous manifestations of IBD. Lower levels of CD3 expression were found on γδ T cells in CD but not in UC, and a lower proportion of γδ T cells expressed CD45RO in CD and UC. Enhanced expression of gut-homing molecules on circulating γδ T cells in IBD and skin-homing molecules in cutaneous manifestations of IBD may be of clinical relevance

The association between valence of social media experiences and depressive symptoms

Background: Social media (SM) may confer emotional benefits via connection with others. However, epidemiologic studies suggest that overall SM is paradoxically associated with increased depressive symptoms. To better understand these findings, we examined the association between positive and negative experiences on SM and depressive symptoms. Methods: We conducted a cross-sectional survey of 1,179 full-time students at the University of West Virginia ages 18–30 in August of 2016. Independent variables were self-reported positive and negative experiences on SM. The dependent variable was depressive symptoms as measured using the Patient-Reported Outcomes Measures Information System. We used multivariable logistic regression to assess associations between SM experiences and depressive symptoms controlling for socio-demographic factors including age, sex, race/ethnicity, education, relationship status, and living situation. Results: Of the 1,179 participants, 62% were female, 28% were non-White, and 51% were single. After controlling for covariates, each 10% increase in positive experiences on SM was associated with a 4% decrease in odds of depressive symptoms, but this was not statistically significant (AOR=0.96; 95% CI=0.91-1.002). However, each 10% increase in negative experiences was associated with a 20% increase in odds of depressive symptoms (AOR=1.20; 95% CI=1.11-1.31). When both independent variables were included in the same model, the association between negative experiences and depressive symptoms remained significant (AOR=1.19, 95% CI=1.10-1.30). Conclusion: Negative experiences online may have higher potency than positive ones because of negativity bias. Future research should examine temporality to determine if it is also possible that individuals with depressive symptomatology are inclined toward negative interactions

Intrinsic gain modulation and adaptive neural coding

In many cases, the computation of a neural system can be reduced to a receptive field, or a set of linear filters, and a thresholding function, or gain curve, which determines the firing probability; this is known as a linear/nonlinear model. In some forms of sensory adaptation, these linear filters and gain curve adjust very rapidly to changes in the variance of a randomly varying driving input. An apparently similar but previously unrelated issue is the observation of gain control by background noise in cortical neurons: the slope of the firing rate vs current (f-I) curve changes with the variance of background random input. Here, we show a direct correspondence between these two observations by relating variance-dependent changes in the gain of f-I curves to characteristics of the changing empirical linear/nonlinear model obtained by sampling. In the case that the underlying system is fixed, we derive relationships relating the change of the gain with respect to both mean and variance with the receptive fields derived from reverse correlation on a white noise stimulus. Using two conductance-based model neurons that display distinct gain modulation properties through a simple change in parameters, we show that coding properties of both these models quantitatively satisfy the predicted relationships. Our results describe how both variance-dependent gain modulation and adaptive neural computation result from intrinsic nonlinearity.Comment: 24 pages, 4 figures, 1 supporting informatio