1,134 research outputs found
Quartzite Fabric Transition in a Cordilleran Metamorphic Core Complex
Photomicrographs 143A-143F record fabric variations in quartzite with increasing structural depth in a \u3e 1 km thick, amphibolite-facies, normal-sense shear zone in the East Humboldt metamorphic core complex, Nevada (Figure 143.1). This shear zone and the overlying detachment system unroofed an infrastructure of high-grade, migmatitic gneiss during Oligocene to early Miocene extension (Dallmeyer and others, 1986; Wright and Snoke, 1993; McGrew and Snee, 1994). Thermobarometric constraints from near the base of the mylonitic zone record deformation conditions of 550°- 620°C and 300-400 MPa (Hurlow and others, 1991). Sample WBC6 (l43A and 143B) characterizes the mylonitic zone, whereas sample 8706-1 (143C and 143D) is transitional in nature, and sample 8727-3 (143E and 143F) represents the infrastructure (Figure 143.1). These three samples record a decreasing contribution from simple shear strain and an actual reversal in shear sense at the deepest structural levels. Inferred variations in quartz deformation mechanisms probably reflect decreasing strain rate and increasing temperature with depth beneath the detachment. We argue that the East Humboldt Range shear system represents a fundamental boundary between an upper crust deforming primarily by rigid block translation and a deeper crust deforming by regional-scale ductile flow
Examining Men’s Perceptions of GBV Prevention Programming Content
As global efforts to engage men in preventing gender-based violence (GBV) continue to grow, understanding male participants’ perceptions of prevention events is needed. Data from a global sample of 319 men who had attended GBV prevention events were used to (a) assess men’s perceptions of what topics were covered, (b) determine whether profiles of these perceptions could be identified, and (c) describe the degree to which content prerception profiles are associated with levels of men’s motivation and confidence related to antiviolence action. Latent class analysis identified four perception profiles of prevention topics. Implications for GBV prevention programming are discussed. © The Author(s) 2018
Dynamics of silver elution from functionalised antimicrobial nanofiltration membranes
In an effort to mitigate biofouling on thin film composite membranes such as nanofiltration and reverse osmosis, a myriad of different surface modification strategies has been published. The use of silver nanoparticles (Ag-NPs) has emerged as being particularly promising. Nevertheless, the stability of these surface modifications is still poorly understood, particularly under permeate flux conditions. Leaching or elution of Ag-NPs from the membrane surface can not only affect the antimicrobial characteristics of the membrane, but could also potentially present an environmental liability when applied in industrial-scale systems. This study sought to investigate the dynamics of silver elution and the bactericidal effect of an Ag-NP functionalised NF270 membrane. Inductively coupled plasma-atomic emission spectroscopy was used to show that the bulk of leached silver occurred at the start of experimental runs, and was found to be independent of salt or permeate conditions used. Cumulative amounts of leached silver did, however, stabilise following the initial release, and were shown to have maintained the biocidal characteristics of the modified membrane, as observed by a higher fraction of structurally damaged Pseudomonas fluorescens cells. These results highlight the need to comprehensively assess the time-dependent nature of bactericidal membranes
Shock tunnel studies of scramjet phenomena, supplement 5
A series of reports are presented on SCRAMjet studies, shock tunnel studies, and expansion tube studies. The SCRAMjet studies include: (1) Investigation of a Supersonic Combustion Layer; (2) Wall Injected SCRAMjet Experiments; (3) Supersonic Combustion with Transvers, Circular, Wall Jets; (4) Dissociated Test Gas Effects on SCRAMjet Combustors; (5) Use of Silane as a Fuel Additive for Hypersonic Thrust Production, (6) Pressure-length Correlations in Supersonic Combustion; (7) Hot Hydrogen Injection Technique for Shock Tunnels; (8) Heat Release - Wave Interaction Phenomena in Hypersonic Flows; (9) A Study of the Wave Drag in Hypersonic SCRAMjets; (10) Parametric Study of Thrust Production in the Two Dimensional SCRAMjet; (11) The Design of a Mass Spectrometer for use in Hypersonic Impulse Facilities; and (12) Development of a Skin Friction Gauge for use in an Impulse Facility. The shock tunnel studies include: (1) Hypervelocity flow in Axisymmetric Nozzles; (2) Shock Tunnel Development; and (3) Real Gas Efects in Hypervelocity Flows over an Inclined Cone. The expansion tube studies include: (1) Investigation of Flow Characteristics in TQ Expansion Tube; and (2) Disturbances in the Driver Gas of a Shock Tube
Hormonal Correlates of Exploratory and Play-Soliciting Behavior in Domestic Dogs
Exploration and play are considered to be crucial behaviors during mammalian development. Even though the relationship between glucocorticoids and exploratory behavior, stress, and anxiety is well described in the literature, very little is known about their role in play behavior in non-rodents. Likewise, the functional role of the “social hormone” oxytocin in exploration, play, stress, and anxiety is still unknown. The present work addresses this literature gap by studying plasma hormone profiles for cortisol (CORT) and oxytocin (OT) of domestic dogs exposed to a novel arena containing two unfamiliar trainers who did not interact with the dogs. We provide evidence suggesting a functional relationship between hormonal measures of cortisol and oxytocin and adaptive behavior (play-soliciting and exploration) in freely behaving domestic dogs. We have taken into account several possible factors in our analyses and interpretations, from the nature and quality of the measurements to demographic factors to statistical robustness. Our results indicate that reduced CORT levels are associated with increments of both play-soliciting behavior frequency and exploratory behavior duration. Furthermore, taken together, our data and our simulations suggest a relationship between OT and the enactment of play-soliciting behaviors by freely behaving domestic dogs that must be further investigated. Future studies should consider naturalistic structured and semi-structured experimental approaches linking behavior with (neuro) physiological measures, taking into account demographic factors such as age and relevant interphase factors such as the sex of the dog; and socio-historic factors such as the playfulness of the dog, history of interaction with young humans, among others, to take full account of interaction between humans and animals in comparative studies (Parada and Rossi, 2018)
A blend of microencapsulated organic acids and botanicals reduces necrotic enteritis via specific signaling pathways in broilers
Necrotic enteritis (NE) is a devastating disease that has seen a resurgence of cases following the removal of antibiotics from feed resulting in financial loss and significant animal health concerns across the poultry industry. The objective was to evaluate the efficacy of a microencapsulated blend of organic (25 % citric and 16.7% sorbic) acids and botanicals (1.7% thymol and 1% vanillin [AviPlus®P]) to reduce clinical NE and determine the signaling pathways associated with any changes. Day-of-hatch by-product broiler breeder chicks were randomly assigned to a control (0) or supplemented (500 g/MT) diet (n=23-26) and evaluated in a NE challenge model (n=3). Birds were administered 2X cocci vaccine on d14 and challenged with a cocktail of Clostridium perfringens strains (107) on d17-19. On d20-21 birds were weighed, euthanized, and scored for NE lesions. Jejunal tissue was collected for kinome analysis using an immuno-metabolism peptide array (n=5; 15/treatment) to compare tissue from supplement-fed birds to controls. Mortality and weight were analyzed using Student's t-test and lesion scores analyzed using F-test two-sample for variances (P<0.05). The kinome data was analyzed using PIIKA2 peptide array analysis software and fold-change between control and treated groups determined. Mortality in the supplemented group was 47.4% and 70.7% in controls (P=0.004). Lesions scores were lower (P=0.006) in supplemented birds (2.47) compared to controls (3.3). Supplement-fed birds tended (P=0.19) to be heavier (848.6g) than controls (796.2g). Kinome analysis showed T cell receptor, TNF and NF-kB signaling pathways contributed to the improvements seen in the supplement-fed birds. The following peptides were significant (P<0.05) in all three pathways: CHUK, MAP3K14, MAP3K7, and NFKB1 indicating their importance. Additionally, there were changes to IL6, IL10, and IFN- γ mRNA expression in tissue between control- and supplement-fed chickens. In conclusion, the addition of a microencapsulated blend of organic acids and botanicals to a broiler diet reduced the clinical signs of NE that was mediated by specific immune-related pathways
Parenting ‘gifted and talented’ children in urban areas: Parents' voices
This is the author's accepted manuscript. The final published article is available from the link below. Copyright © 2014 by SAGE Publications.International evidence demonstrates the importance of engaging parents in the education of their ‘high-potential’ children, yet limited research has focused on the involvement of parents from differing economic strata/backgrounds. The current study explored the dilemmas of parenting academically high-ability children from economically deprived urban areas in the UK. Data were gathered from a sample of parents whose children attended a university-based sustained intervention programme for designated ‘gifted’ pupils aged 12–16. Parental perceptions were sought in relation to (a) the usefulness/impact of the intervention programme, (b) parents’ aspirations for their children growing up in economically deprived urban areas and (c) parents’ views on the support provided by the extended family, peer groups and the wider community. The findings have significant implications for both policy and practice and, more specifically, for engaging parents in intervention programmes offered by universities and schools to children in order to increase their access to higher education and for enhancing their life chances
Large-Scale Bioinformatics Analysis of Bacillus Genomes Uncovers Conserved Roles of Natural Products in Bacterial Physiology
ABSTRACT Bacteria possess an amazing capacity to synthesize a diverse range of structurally complex, bioactive natural products known as specialized (or secondary) metabolites. Many of these specialized metabolites are used as clinical therapeutics, while others have important ecological roles in microbial communities. The biosynthetic gene clusters (BGCs) that generate these metabolites can be identified in bacterial genome sequences using their highly conserved genetic features. We analyzed an unprecedented 1,566 bacterial genomes from Bacillus species and identified nearly 20,000 BGCs. By comparing these BGCs to one another as well as a curated set of known specialized metabolite BGCs, we discovered that the majority of Bacillus natural products are comprised of a small set of highly conserved, well-distributed, known natural product compounds. Most of these metabolites have important roles influencing the physiology and development of Bacillus species. We identified, in addition to these characterized compounds, many unique, weakly conserved BGCs scattered across the genus that are predicted to encode unknown natural products. Many of these “singleton” BGCs appear to have been acquired via horizontal gene transfer. Based on this large-scale characterization of metabolite production in the Bacilli , we go on to connect the alkylpyrones, natural products that are highly conserved but previously biologically uncharacterized, to a role in Bacillus physiology: inhibiting spore development. IMPORTANCE Bacilli are capable of producing a diverse array of specialized metabolites, many of which have gained attention for their roles as signals that affect bacterial physiology and development. Up to this point, however, the Bacillus genus’s metabolic capacity has been underexplored. We undertook a deep genomic analysis of 1,566 Bacillus genomes to understand the full spectrum of metabolites that this bacterial group can make. We discovered that the majority of the specialized metabolites produced by Bacillus species are highly conserved, known compounds with important signaling roles in the physiology and development of this bacterium. Additionally, there is significant unique biosynthetic machinery distributed across the genus that might lead to new, unknown metabolites with diverse biological functions. Inspired by the findings of our genomic analysis, we speculate that the highly conserved alkylpyrones might have an important biological activity within this genus. We go on to validate this prediction by demonstrating that these natural products are developmental signals in Bacillus and act by inhibiting sporulation
Effect of local environment and stellar mass on galaxy quenching and morphology at
We study galactic star-formation activity as a function of environment and
stellar mass over 0.5<z<2.0 using the FourStar Galaxy Evolution (ZFOURGE)
survey. We estimate the galaxy environment using a Bayesian-motivated measure
of the distance to the third nearest neighbor for galaxies to the stellar mass
completeness of our survey, at z=1.3 (2.0). This
method, when applied to a mock catalog with the photometric-redshift precision
(), recovers galaxies in low- and high-density
environments accurately. We quantify the environmental quenching efficiency,
and show that at z> 0.5 it depends on galaxy stellar mass, demonstrating that
the effects of quenching related to (stellar) mass and environment are not
separable. In high-density environments, the mass and environmental quenching
efficiencies are comparable for massive galaxies (
10.5) at all redshifts. For lower mass galaxies (
10), the environmental quenching efficiency is very low at 1.5, but
increases rapidly with decreasing redshift. Environmental quenching can account
for nearly all quiescent lower mass galaxies ( 9-10),
which appear primarily at 1.0. The morphologies of lower mass
quiescent galaxies are inconsistent with those expected of recently quenched
star-forming galaxies. Some environmental process must transform the
morphologies on similar timescales as the environmental quenching itself. The
evolution of the environmental quenching favors models that combine gas
starvation (as galaxies become satellites) with gas exhaustion through
star-formation and outflows ("overconsumption"), and additional processes such
as galaxy interactions, tidal stripping and disk fading to account for the
morphological differences between the quiescent and star-forming galaxy
populations.Comment: 29 pages, 15 figure, accepted for publication in Ap
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