Properties of ion implanted Ti-6Al-4V processed using beamline and PSII techniques

The surface of Ti-6Al-4V (Ti64) alloy has been modified using beamline implantation of boron. In separate experiments, Ti64 has been implanted with nitrogen using a plasma source ion implantation (PSII) technique utilizing either ammonia (NH{sub 3}), nitrogen (N{sub 2}), or their combinations as the source of nitrogen ions. Beamline experiments have shown the hardness of the N-implanted surface saturates at a dose level of {approximately} 4 {times} 10{sup 17} at/cm{sup 2} at {approximately} 10 GPa. The present work makes comparisons of hardness and tribological tests of (1) B implantation using beamline techniques, and (2) N implanted samples using ammonia and/or nitrogen gas in a PSII process. The results show that PSII using N{sub 2} or NH{sub 3} gives similar hardness as N implantation using a beamline process. The presence of H in the Ti alloy surface does not affect the hardness of the implanted surface. Boron implantation increased the surface hardness by as much as 2.5x at the highest dose level. Wear testing by a pin-on-disk method indicated that nitrogen implantation reduced the wear rate by as much as 120x, and boron implantation reduced the wear rate by 6.5x. Increased wear resistance was accompanied by a decreased coefficient of friction

Properties of Ion Implanted Ti-6Al-4V Processed using Beamline and PSII Techniques

The surface of Ti-6Al-4V (Ti64) alloy has been modified using beamline implantation of boron. In separate experiments, Ti64 has been implanted with nitrogen using a plasma source ion implantation (PSII) technique utilizing either ammonia (NH{sub 3}), nitrogen (N{sub 2}), or their combinations as the source of nitrogen ions. Beamline experiments have shown the hardness of the N-implanted surface saturates at a dose level of {approximately} 4 {times} 10{sup 17} at/cm{sup 2} at {approximately} 10 GPa. The present work makes comparisons of hardness and tribological tests of (1) B implantation using beamline techniques, and (2) N implanted samples using ammonia and/or nitrogen gas in a PSII process. The results show that PSII using N{sub 2} or NH{sub 3} gives similar hardness as N implantation using a beamline process. The presence of H in the Ti alloy surface does not affect the hardness of the implanted surface. Boron implantation increased the surface hardness by as much as 2.5x at the highest dose level. Wear testing by a pin-on-disk method indicated that nitrogen implantation reduced the wear rate by as much as 120x, and boron implantation reduced the wear rate by 6.5x. Increased wear resistance was accompanied by a decreased coefficient of friction

Broadening Exposure to Socio-Political Opinions via a Pushy Smart Home Device

Motivated by the effects of the filter bubble and echo chamber phenomena on social media, we developed a smart home device, Spkr, that unpredictably “pushes” socio-political discussion topics into the home. The device utilised trending Twitter discussions, categorised by their socio-political alignment, to present people with a purposefully assorted range of viewpoints. We deployed Spkr in 10 homes for 28 days with a diverse range of participants and interviewed them about their experiences. Our results show that Spkr presents a novel means of combating selective exposure to socio-political issues, providing participants with identifiably diverse viewpoints. Moreover, Spkr acted as a conversational prompt for discussion within the home, initiating collective processes and engaging those who would not often be involved in political discussions. We demonstrate how smart home assistants can be used as a catalyst for provocation by altering and pluralising political discussions within households

Potential of grass invasions in desert shrublands to create novel ecosystem states under variable climate

The invasion of exotic grasses into shrublands is a major disturbance to dryland ecosystems. The presence of exotic grasses enhances the occurrence of wildfire in landscapes that had not evolved in the presence of fire, leading to high rates of mortality of the native vegetation. Exotic grasses could be more prone to water stress and mortality than the shrubs they replaced and may not establish during drought, facts that are crucial in ecosystems undergoing increased climatic variability. Here, we develop a process-based modelling framework to investigate the complex dynamics resulting from the introduction of exotic grasses under variable climate. We find that the system converges towards different steady states, depending on the magnitude of climatic variability. While in the absence of climate fluctuations the shrubland state is replaced by an exotic grassland, interannual climate variability may inhibit grass invasion and stabilize the shrubland state. However, climatic variability also gives rise to a novel third, unvegetated state, with grass invasion being followed by drought, grass mortality and intense soil erosion. Most of the research on climate change effects on ecosystems has historically concentrated on the ecological impact of shifts in mean climate conditions. This study shows that changes in the variance are also important when shifts in vegetation composition (e.g. species invasions) result in different susceptibility to climatic variability. In the presence of random climate fluctuations, ecosystems can display steady states that differ from those that would exist under a constant climate or with a climate trend. Copyright © 2016 John Wiley & Sons, Ltd

Novel Blood Pressure Locus and Gene Discovery Using Genome-Wide Association Study and Expression Data Sets From Blood and the Kidney.

Elevated blood pressure is a major risk factor for cardiovascular disease and has a substantial genetic contribution. Genetic variation influencing blood pressure has the potential to identify new pharmacological targets for the treatment of hypertension. To discover additional novel blood pressure loci, we used 1000 Genomes Project-based imputation in 150 134 European ancestry individuals and sought significant evidence for independent replication in a further 228 245 individuals. We report 6 new signals of association in or near HSPB7, TNXB, LRP12, LOC283335, SEPT9, and AKT2, and provide new replication evidence for a further 2 signals in EBF2 and NFKBIA Combining large whole-blood gene expression resources totaling 12 607 individuals, we investigated all novel and previously reported signals and identified 48 genes with evidence for involvement in blood pressure regulation that are significant in multiple resources. Three novel kidney-specific signals were also detected. These robustly implicated genes may provide new leads for therapeutic innovation

A Meta-analysis of Gene Expression Signatures of Blood Pressure and Hypertension

Genome-wide association studies (GWAS) have uncovered numerous genetic variants (SNPs) that are associated with blood pressure (BP). Genetic variants may lead to BP changes by acting on intermediate molecular phenotypes such as coded protein sequence or gene expression, which in turn affect BP variability. Therefore, characterizing genes whose expression is associated with BP may reveal cellular processes involved in BP regulation and uncover how transcripts mediate genetic and environmental effects on BP variability. A meta-analysis of results from six studies of global gene expression profiles of BP and hypertension in whole blood was performed in 7017 individuals who were not receiving antihypertensive drug treatment. We identified 34 genes that were differentially expressed in relation to BP (Bonferroni-corrected p<0.05). Among these genes, FOS and PTGS2 have been previously reported to be involved in BP-related processes; the others are novel. The top BP signature genes in aggregate explain 5%–9% of inter-individual variance in BP. Of note, rs3184504 in SH2B3, which was also reported in GWAS to be associated with BP, was found to be a trans regulator of the expression of 6 of the transcripts we found to be associated with BP (FOS, MYADM, PP1R15A, TAGAP, S100A10, and FGBP2). Gene set enrichment analysis suggested that the BP-related global gene expression changes include genes involved in inflammatory response and apoptosis pathways. Our study provides new insights into molecular mechanisms underlying BP regulation, and suggests novel transcriptomic markers for the treatment and prevention of hypertension

SYSTEMATICS OF \u3ci\u3eMESOCESTOIDES\u3c/i\u3e (CESTODA: MESOCESTOIDIDAE): EVALUATION OF MOLECULAR AND MORPHOLOGICAL VARIATION AMONG ISOLATES

A hypothesis-based framework was used to test if 3 genetic strains of Mesocestoides (clades A, B, and C) are distinct evolutionary lineages, thereby supporting their delimitation as species. For comparative purposes, 3 established cestode species, Taenia pisiformis, Taenia serialis, and Taenia crassiceps were assessed using the same methods. Sequence data from mitochondrial rDNA (12S) and the second internal transcribed spacer of nuclear rDNA (ITS-2) revealed derived (autapomorphic) characters for lineages representing clade A (n = 6 autapomorphies), clade B (n = 4), and clade C (n = 9) as well as T. pisiformis (n = 15) and T. serialis (n = 12). Furthermore, multivariate analysis of morphological data revealed significant differences among the 3 genetic strains of Mesocestoides and between T. pisiformis and T. serialis. The level of phenotypic variation within evolutionary lineages of Mesocestoides and Taenia spp. tapeworms was similar. Results from this study support recognizing Mesocestoides clades A, B, and C as separate species, and provide evidence that clade B and Mesocestoides vogae are conspecific

Adherent diamond like carbon coatings on metals via plasma source ion implantation

Various techniques are currently used to produce diamond-like carbon (DLC) coatings on various materials. Many of these techniques use metallic interlayers, such as Ti or Si, to improve the adhesion of a DLC coating to a ferrous substrate. An alternative processing route would be to use plasma source ion implantation (PSII) to create a carbon composition gradient in the surface of the ferrous material to serve as the interface for a DLC coating. The need for interlayer deposition is eliminated by using a such a graded interfaces PSII approach has been used to form adherent DLC coatings on magnesium, aluminum, silicon, titanium, chromium, brass, nickel, and tungsten. A PSII process tailored to create a graded interface allows deposition of adherent DLC coatings even on metals that exhibit a positive heat of formation with carbon, such as magnesium, iron, brass and nickel

Prenatal exposure to the probiotic Lactococcus lactis decreases anxiety-like behavior and modulates cortical cytoarchitecture in a sex specific manner.

Development of the cerebral cortex may be influenced by the composition of the maternal gut microbiota. To test this possibility, we administered probiotic Lactococcus lactis in drinking water to mouse dams from day 10.5 of gestation until pups reached postnatal day 1 (P1). Pups were assessed in a battery of behavioral tests starting at 10 weeks old. We found that females, but not males, exposed to probiotic during prenatal development spent more time in the center of the open field and displayed decreased freezing time in cue associated learning, compared to controls. Furthermore, we found that probiotic exposure changed the density of cortical neurons and increased the density of blood vessels in the cortical plate of P1 pups. Sex-specific differences were observed in the number of mitotic neural progenitor cells, which were increased in probiotic exposed female pups. In addition, we found that probiotic treatment in the latter half of pregnancy significantly increased plasma oxytocin levels in mouse dams, but not in the offspring. These results suggest that exposure of naïve, unstressed dams to probiotic may exert sex-specific long-term effects on cortical development and anxiety related behavior in the offspring