Near-infrared Variability among YSOs in the Star Formation Region Cygnus OB7

We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 square degree region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer (WISE), we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field imaging CAMera (WFCAM) on the United Kingdom InfraRed Telescope (UKIRT), we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J ~17. We study detailed light curves and color trajectories of ~50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on time scales of a few years. We divide the variability into four observational classes: 1) stars with periodic variability stable over long timescales, 2) variables which exhibit short-lived cyclic behavior, 3) long duration variables, and 4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of < 1Myr, with at least one individual, wildly varying, source ~ 100,000 yr old. We have also discovered a Class II eclipsing binary system with a period of 17.87 days.Comment: ApJ accepted: 44 pages includes 5 tables and 16 figures. Some figures condensed for Astro/p

Comparative genomics of clinical strains of Pseudomonas aeruginosa strains isolated from different geographic sites

© 2018, The Author(s). The large and complex genome of Pseudomonas aeruginosa, which consists of significant portions (up to 20%) of transferable genetic elements contributes to the rapid development of antibiotic resistance. The whole genome sequences of 22 strains isolated from eye and cystic fibrosis patients in Australia and India between 1992 and 2007 were used to compare genomic divergence and phylogenetic relationships as well as genes for antibiotic resistance and virulence factors. Analysis of the pangenome indicated a large variation in the size of accessory genome amongst 22 stains and the size of the accessory genome correlated with number of genomic islands, insertion sequences and prophages. The strains were diverse in terms of sequence type and dissimilar to that of global epidemic P. aeruginosa clones. Of the eye isolates, 62% clustered together within a single lineage. Indian eye isolates possessed genes associated with resistance to aminoglycoside, beta-lactams, sulphonamide, quaternary ammonium compounds, tetracycline, trimethoprims and chloramphenicols. These genes were, however, absent in Australian isolates regardless of source. Overall, our results provide valuable information for understanding the genomic diversity of P. aeruginosa isolated from two different infection types and countries

AIDS and pregnancy risk-taking behavior in adolescence : an exploratory study.

Over 1,000,000 adolescent girls become pregnant each year, and nearly half of these girls give birth. Individuals between the ages of 20 and 29 account for nearly 20% of all documented AIDS cases. Given the long incubation period for the AIDS virus, many of these individuals were probably infected during sexual activity in adolescence. This exploratory research examined the predictive ability of demographic, developmental and personality variables on becoming sexually active, and on AIDS risk-taking and pregnancy risk-taking behavior in middle adolescence. A sample of 381 high school students (204 females, 177 males), age 14-18, from a town in Western Massachusetts completed a questionnaire. The majority of the sample (57%) reported having had sexual intercourse. Having a sexually active best friend, lower school achievement (GPA), lesser perceived parental support, and high sensation seeking needs were all associated with experience with sexual intercourse. Participants who initiated intercourse at a younger age, had higher sensation seeking needs, a sexual abuse history, and who were older were those who exhibited the highest levels of AIDS risk-taking behavior. Participants who were younger, who initiated sex earlier, and had a sexual abuse history were those most likely to exhibit pregnancy risk-taking behavior. Some significant gender differences were noted for factors influencing sexual risk-taking. Results provide further support for the effects of sexual abuse on adolescent development and sexuality. The findings suggest a need for education in middle and elementary school, and the importance of using peer-led intervention efforts

Metabolism of labeled organic nitrogen in soil: regulation by inorganic nitrogen

Includes bibliographical references (page 773).Regulation of organic N metabolism by inorganic N availability was investigated in short-term laboratory incubations of soil. A 14C-, 15N-labeled organic N substrate was produced by growing Pseudomonas stutzeri in labeled media and isolating a cytoplasmic fraction. This was added to soils that had been preincubated with glucose or glucose plus NH+4 to induce conditions of N deficiency or sufficiency. Regulation by inorganic N was indicated by stimulated proteolytic enzyme activity and greater initial rates of cytoplasmic 14C mineralization in N deficient soils. However, effects of N deficiency on 14C mineralization persisted for no more than 24 h. Preinduced N deficiency significantly decreased the extent of 15N mineralized from cytoplasmic N. Mineralization of 14C from leucine added to soil was similarly affected by N availability, yet 14C-glutamate mineralization was apparently unaffected. In another experiment labeled cytoplasm was added simultaneously with or without a larger quantity of glucose. The glucose caused virtually complete assimilation of 15N but had no effect on apparent assimilation of 14C. Thus, there was no relationship between 15N assimilation and 14C assimilation, suggesting that the C and N contained in organic N are processed separately by soil microbes. Inorganic N availability may have short-term effects on metabolism of C in organic N but long-lasting effects appear to be minimal

A Trustworthiness of Commercial Airline Pilots (T-CAP) Scale for Indian Consumers

A Trustworthiness of Commercial Airline Pilots (T-CAP) Scale was created for the purpose of measuring consumer perceptions about the trustworthiness of pilots in India. Previous research has used several different types of trust and trustworthiness scales, but none of them focus on pilot trustworthiness, particularly with an Indian consumer base. This paper outlines the process by which we validated the scale and tested reliability. We had 679 participants join in the process of determining the items that belonged in the scale, narrowing down the choices to highly relevant items, and testing the final scale. A factor analysis using the principle components and varimax rotation produced a single factor for the condition of trustworthiness, and all the items strongly loaded on this one factor. Reliability was tested via Cronbach’s Alpha and Guttmann’s Split-half test. Finally, the scale was tested in an experimental setting to determine discriminability. All tests provided evidence of high validity, reliability and discriminability

Accessory genome contributes to the virulence and resistance of the ocular isolate of Pseudomonas aeruginosa: A complete genome analysis

Bacteria can acquire an accessory genome through the horizontal transfer of genetic elements from non-parental lineages. This leads to rapid genetic evolution allowing traits such as antibiotic resistance and virulence to spread through bacterial communities. The study of complete genomes of bacterial strains helps to understand the genomic traits associated with virulence and antibiotic resistance. We aimed to investigate the complete accessory genome of an ocular isolate of P. aeruginosa. We obtained the complete genome of the ocular isolate strain PA34 of P. aeruginosa utilising genome sequence reads from Illumina and Oxford Nanopore Technology followed by PCR to close any identified gaps. In-depth genomic analysis was performed using various bioinformatics tools. The phenotypic properties of susceptibility to heavy metals and cytotoxicity were determined to confirm expression of certain traits. The complete genome of PA34 includes a chromosome of 6.8 Mbp and two plasmids of 95.4 Kbp (pMKPA34-1) and 26.8 Kbp (pMKPA34-2). PA34 had a large accessory genome of 1,213 genes and had 543 unique genes not present in other strains. These exclusive genes encoded features related to metal and antibiotic resistance, phage integrase and transposons. At least 24 GIs were predicated in the complete chromosome, of which two were integrated into novel sites. Eleven GIs carried virulence factors or replaced pathogenic genes. A bacteriophage carried the aminoglycoside resistance gene (aac(3)-IId). The two plasmids carried other six antibiotic resistance genes. The large accessory genome of this ocular isolate plays a large role in shaping its virulence and antibiotic resistance

A Systematic Review of Genetic Influence on Psychological Resilience

When exposed to adversity, some individuals are at an increased risk of posttraumatic stress disorder, experiencing persistent biopsychosocial disturbances, whereas others adapt well, described as resilience. Resilience is a complex biopsychosocial phenomenon conceptualized as adaptation to adversity influenced by an individual’s genetic variants, epistasis, epigenetics, and gene-by-environment interactions. Studies on psychological resilience have focused on behavioral and psychosocial variables with far less examination of the genetic contributions. The purpose of this review is to identify specific genetic variants contributing to the biological capacity for psychological resilience. PubMed and PsycINFO were searched using the following key words: psychological resilience AND genotype(s). Additional articles were identified from the Human Genome Epidemiology Navigator using the term resilience, psychological. Ten studies met the criteria. Six genes were empirically associated with psychological resilience: serotonin-transporter-linked polymorphic region (5-HTTLPR), dopamine receptor D4, brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone receptor 1, oxytocin receptor and regulator of G-protein signaling 2. The findings of this systematic review suggest that the L/L or L′/L′ genotype of 5-HTTLPR and rs25531 in children/adolescents and the S/S or S′/S′ genotype in adults are most frequently related to resilience. Additionally, the Val/Val genotype of rs6265 in BDNF in Caucasians was also associated with resilience. There are numerous factors contributing to the complexity of determining the genetic influence on resilience including analysis of rs25531, assumptions of the mode of inheritance, operationalization of resilience, demographic and population characteristics, sample size, and other types of genetic influence including epistasis and epigenetics. While current evidence is supportive, further investigation of the genetic influence on resilience is required

Radio Polarimetry of the ELAIS N1 Field: Polarized Compact Sources

We present deep polarimetric observations at 1420 MHz of the European Large Area ISO Survey North 1 region (ELAIS N1) as part of the Dominion Radio Astrophysical Observatory Planck Deep Fields project. By combining closely spaced aperture synthesis fields, we image a region of 7.43 square degrees to a maximum sensitivity in Stokes Q and U of 78 microJy/beam, and detect 786 compact sources in Stokes I. Of these, 83 exhibit polarized emission. We find that the differential source counts (log N - log p) for polarized sources are nearly constant down to p > 500 microJy, and that these faint polarized radio sources are more highly polarized than the strong source population. The median fractional polarization is (4.8 +/- 0.7)% for polarized sources with Stokes I flux density between 1 and 30 mJy; approximately three times larger than sources with I > 100 mJy. The majority of the polarized sources have been identified with galaxies in the Spitzer Wide Area Infrared Extragalactic Survey (SWIRE) image of ELAIS N1. Most of the galaxies occupy regions in the IRAC 5.8/3.6 micron vs. 8.0/4.5 micron color-color diagram associated with dusty AGNs, or with ellipticals with an aging stellar population. A few host galaxies have colors that suggests significant PAH emission in the near-infrared. A small fraction, 12%, of the polarized sources are not detected in the SWIRE data. None of the polarized sources in our sample appears to be associated with an actively star-forming galaxy.Comment: 28 pages, 8 Figures. Figures 2 and 3 as separate gif images. Accepted for publication in the Astrophysical Journa