Nonlinear Ultrasonic Properties of As-Quenched Steels

We have investigated the effect of carbon content on the nonlinear ultrasonic parameter β and the longitudinal phase velocity v L in a series of martensitic steel specimens. The specimens were measured in the as-quenched state to insure that the carbon was present primarily as an interstitial in the martensite. Experimentally, β increased with increasing mass percent carbon (or hardness), while v Lremained virtually the same for all specimens. Therefore we conclude that β is sensitive to microstructural variations between the specimens, but v L is not. X-ray diffraction experiments indicate that the dislocation density in the specimens is high (∼1011/cm2) and increases with increasing carbon content. These results support the hypothesis that the observed increase in β may be attributed to dislocations affected by internal stresses in the quenched specimens

Response of the Hepatic Transcriptome to Aflatoxin B1 in Domestic Turkey (Meleagris gallopavo)

Dietary exposure to aflatoxin B1 (AFB1) is detrimental to avian health and leads to major economic losses for the poultry industry. AFB1 is especially hepatotoxic in domestic turkeys (Meleagris gallopavo), since these birds are unable to detoxify AFB1 by glutathione-conjugation. The impacts of AFB1 on the turkey hepatic transcriptome and the potential protection from pretreatment with a Lactobacillus-based probiotic mixture were investigated through RNA-sequencing. Animals were divided into four treatment groups and RNA was subsequently recovered from liver samples. Four pooled RNA-seq libraries were sequenced to produce over 322 M reads totaling 13.8 Gb of sequence. Approximately 170,000 predicted transcripts were de novo assembled, of which 803 had significant differential expression in at least one pair-wise comparison between treatment groups. Functional analysis linked many of the transcripts significantly affected by AFB1 exposure to cancer, apoptosis, the cell cycle or lipid regulation. Most notable were transcripts from the genes encoding E3 ubiquitin-protein ligase Mdm2, osteopontin, S-adenosylmethionine synthase isoform type-2, and lipoprotein lipase. Expression was modulated by the probiotics, but treatment did not completely mitigate the effects of AFB1. Genes identified through transcriptome analysis provide candidates for further study of AFB1 toxicity and targets for efforts to improve the health of domestic turkeys exposed to AFB1.published_or_final_versio

Antenatal screening and the gendering of genetic responsibility

<p>Abstract</p> <p>Background</p> <p>The objective of this study is to explore men's and women's perceptions of antenatal blood screening. The study will assess the impact of these perceptions on decision-making regarding diagnostic testing and selective abortion, and on parental feelings of genetic responsibility. By exploring gender and antenatal screening in this way, the research aims to contribute to our understanding of lay perceptions of genetic screening and increase our knowledge of the decision-making process in screening.</p> <p>Research design</p> <p>This qualitative study will be based on semi-structured interviews with twenty pregnant women and twenty male partners in the post-industrial city of Sheffield, UK. All interviews will be taped, transcribed and analysed thematically using NVIVO, a qualitative software package.</p> <p>Discussion</p> <p>The findings of this study have relevance to existing debates on the social and ethical implications of reproductive genetics. A better understanding of male and female perceptions of the screening process could improve guidance and practice in antenatal screening and genetic counselling. It will also inform and contribute to the development of theory on gender and genetic screening.</p

Problematic internet users' skin conductance and anxiety increase after exposure to the internet

Introduction: To examine the impact of cessation of an internet session on skin conductance responses and anxiety of higher and lower problem internet users, in order to explore possible physiological withdrawal effects. Method: Participants were measured in terms of their skin conductance before (15 min), during (15 min), and after (15 min) an internet session, and completed self-report measures of state anxiety and problematic intemet use. Results: Higher, but not lower, problem users showed increased skin conductance after intemet use was stopped, relative to before their internet session. Higher problem users' GSR scores increased, as the time from intemet cessation became longer. Higher problem users also showed increased levels of anxiety, following their intemet session, which correlated with their skin conductance scores. Conclusions: These results suggest that, following termination of an intemet session, withdrawal-like effects are seen, both psychologically and physiologically

Evidence for an Internet Addiction Disorder

OBJECTIVE: This study examined whether exposure to the Internet could create a preference for colors associated with visited Web sites and explored the possible relationship with self-reported problematic Internet use and Internet deprivation. METHOD: 100 adult participants were divided into 2 groups; one was deprived access to the Internet for 4 hours, and the other was not. After this period, they were asked to choose a color and complete a series of psychometric questionnaires concerning mood (Positive and Negative Affect Schedule), anxiety (Spielberger State-Trait Anxiety Inventory), and depression (Beck Depression Inventory). They were then given a 15-minute exposure to the Internet, and the Web sites they visited were recorded. They were then asked to again choose a color, complete the same psychometric questionnaires, and complete the Internet Addiction Test. The study was conducted between November 2013 and April 2014. RESULTS: For Internet-deprived, but not nondeprived, subjects, a reduction of mood and increased anxiety was noted in the higher problematic Internet users following Web cessation. There was also a shift toward choosing the color most prominent on the visited Web sites in these participants. No shift in mood, or toward choosing the dominant Web site color, was seen in the lower problem users. CONCLUSIONS: These findings suggest that the Internet can serve as a negative reinforcer for behavior in higher problem users and that the reinforcement obtained from the alleviation of withdrawal symptoms becomes conditioned, with the color and appearance of the visited Web sites giving them a more positive value

Differential physiological changes following internet exposure in higher and lower problematic internet users

Problematic internet use (PIU) has been suggested as in need of further research with a view to being included as a disorder in future Diagnostic and Statistical Manual (DSM) of the American Psychiatric Association, but lack of knowledge about the impact of internet cessation on physiological function remains a major gap in knowledge and a barrier to PIU classification. One hundred and forty-four participants were assessed for physiological (blood pressure and heart rate) and psychological (mood and state anxiety) function before and after an internet session. Individuals also completed a psychometric examination relating to their usage of the internet, as well as their levels of depression and trait anxiety. Individuals who identified themselves as having PIU displayed increases in heart rate and systolic blood pressure, as well as reduced mood and increased state of anxiety, following cessation of internet session. There were no such changes in individuals with no self-reported PIU. These changes were independent of levels of depression and trait anxiety. These changes after cessation of internet use are similar to those seen in individuals who have ceased using sedative or opiate drugs, and suggest PIU deserves further investigation and serious consideration as a disorder

Risks and benefits of bisphosphonates

Bone is the most common site for metastasis in cancer and is of particular clinical importance in breast and prostate cancers due to the prevalence of these diseases. Bone metastases result in considerable morbidity and complex demands on health care resources, affecting quality of life and independence over years rather than months. The bisphosphonates have been shown to reduce skeletal morbidity in multiple myeloma as well as a wide range of solid tumours affecting bone by 30–50%. Quite appropriately, these agents are increasingly used alongside anticancer treatments to prevent skeletal complications and relieve bone pain

Pathogenesis of aerosolized Eastern Equine Encephalitis virus infection in guinea pigs

Mice and guinea pigs were experimentally exposed to aerosols containing regionally-distinct strains (NJ1959 or ArgM) of eastern equine encephalitis virus (EEEV) at two exclusive particle size distributions. Mice were more susceptible to either strain of aerosolized EEEV than were guinea pigs; however, clinical signs indicating encephalitis were more readily observed in the guinea pigs. Lower lethality was observed in both species when EEEV was presented at the larger aerosol distribution (> 6 μm), although the differences in the median lethal dose (LD50) were not significant. Virus isolation and immunohistochemistry indicated that virus invaded the brains of guinea pigs within one day postexposure, regardless of viral strain or particle size distribution. Immunohistochemistry further demonstrated that neuroinvasion occurred through the olfactory system, followed by transneuronal spread to all regions of the brain. Olfactory bipolar neurons and neurons throughout the brain were the key viral targets. The main microscopic lesions in infected guinea pigs were neuronal necrosis, inflammation of the meninges and neuropil of the brain, and vasculitis in the brain. These results indicate that guinea pigs experimentally infected by aerosolized EEEV recapitulate several key features of fatal human infection and thus should serve as a suitable animal model for aerosol exposure to EEEV

Asteroseismology

Asteroseismology is the determination of the interior structures of stars by using their oscillations as seismic waves. Simple explanations of the astrophysical background and some basic theoretical considerations needed in this rapidly evolving field are followed by introductions to the most important concepts and methods on the basis of example. Previous and potential applications of asteroseismology are reviewed and future trends are attempted to be foreseen.Comment: 38 pages, 13 figures, to appear in: "Planets, Stars and Stellar Systems", eds. T. D. Oswalt et al., Springer Verla