657 research outputs found
The Brotherly Task
Between the years 1951 and 1956 I sat out there where you are with enough regularity that no one ever got overly concerned about my spiritual condition. Back in those days, it seems to me, there was less concern about the spiritual condition and more concern about chapel attendance. I think that\u27s progress. During those years I sat out there I remembered thinking, frequently, that I did not want to be up here in the chancel-ever! - that the good place to be was out there-not up here. I was right; but as we say: That\u27s my problem
Repeatedly Evolved Host-Specific Ectosymbioses between Sulfur-Oxidizing Bacteria and Amphipods Living in a Cave Ecosystem
Ectosymbioses between invertebrates and sulfur-oxidizing bacteria are widespread in sulfidic marine environments and have evolved independently in several invertebrate phyla. The first example from a freshwater habitat, involving Niphargus ictus amphipods and filamentous Thiothrix ectosymbionts, was recently reported from the sulfide-rich Frasassi caves in Italy. Subsequently, two new Niphargus species, N. frasassianus and N. montanarius, were discovered within Frasassi and found to co-occur with N. ictus. Using a variety of microscopic and molecular techniques, we found that all three Frasassi-dwelling Niphargus species harbor Thiothrix ectosymbionts, which belong to three distinct phylogenetic clades (named T1, T2, and T3). T1 and T3 Thiothrix dominate the N. frasassianus ectosymbiont community, whereas T2 and T3 are prevalent on N. ictus and N. montanarius. Relative distribution patterns of the three ectosymbionts are host species-specific and consistent over different sampling locations and collection years. Free-living counterparts of T1–T3 are rare or absent in Frasassi cave microbial mats, suggesting that ectosymbiont transmission among Niphargus occurs primarily through inter- or intraspecific inoculations. Phylogenetic analyses indicate that the Niphargus-Thiothrix association has evolved independently at least two times. While ectosymbioses with T1 and T2 may have been established within Frasassi, T3 ectosymbionts seem to have been introduced to the cave system by Niphargus
The EGNoG Survey: Gas Excitation in Normal Galaxies at z~0.3
As observations of molecular gas in galaxies are pushed to lower star
formation rate galaxies at higher redshifts, it is becoming increasingly
important to understand the conditions of the gas in these systems to properly
infer their molecular gas content. The rotational transitions of the carbon
monoxide (CO) molecule provide an excellent probe of the gas excitation
conditions in these galaxies. In this paper we present the results from the gas
excitation sample of the Evolution of molecular Gas in Normal Galaxies (EGNoG)
survey at the Combined Array for Research in Millimeter-wave Astronomy (CARMA).
This subset of the full EGNoG sample consists of four galaxies at z~0.3 with
star formation rates of 40-65 M_Sun yr^-1 and stellar masses of ~2x10^11 M_Sun.
Using the 3 mm and 1 mm bands at CARMA, we observe both the CO(1-0) and CO(3-2)
transitions in these four galaxies in order to probe the excitation of the
molecular gas. We report robust detections of both lines in three galaxies (and
an upper limit on the fourth), with an average line ratio, r_31 = L'_CO(3-2) /
L'_CO(1-0), of 0.46 \pm 0.07 (with systematic errors \lesssim 40%), which
implies sub-thermal excitation of the CO(3-2) line. We conclude that the
excitation of the gas in these massive, highly star-forming galaxies is
consistent with normal star-forming galaxies such as local spirals, not
starbursting systems like local ultra-luminous infrared galaxies. Since the
EGNoG gas excitation sample galaxies are selected from the main sequence of
star-forming galaxies, we suggest that this result is applicable to studies of
main sequence galaxies at intermediate and high redshifts, supporting the
assumptions made in studies that find molecular gas fractions in star forming
galaxies at z~1-2 to be an order of magnitude larger than what is observed
locally.Comment: Accepted for publication in the Astrophysical Journal, to appear
January 2013; 18 pages, 10 figures, 6 table
Interactive voice response system (IVRS): Data quality considerations and lessons learned during a microbicide placebo adherence trial with young men who have sex with men.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106616/1/Interactive voice response system IVRS Data quality considerations and lessons learned during a microbicide placebo adherence trial with young men who have sex with men.pd
Miniaturized biosignature analysis reveals implications for the formation of cold seep carbonates at Hydrate Ridge (off Oregon, USA)
Methane-related carbonates from Hydrate Ridge typically show several macroscopically distinguishable mineral phases, namely whitish aragonite, lucent aragonite, and gray micrite. The relationship of these phases to particular microorganisms or biogeochemical processes is as yet unclear. We used a miniaturized biomarker technique on mg samples, combined with factor analysis and subsequent electron microprobe analysis, to study lipid biomarkers and chemical compositions of the individual phases. This allows us to identify particular mechanisms involved in the formation of the different carbonate precipitates. Our combined analysis of biomarkers and petrographic traits shows that most of the lipids related to the anaerobic oxidation of methane (>90% by weight) are concentrated within only a minor compartment (~20% by volume) of the Hydrate Ridge carbonates, the whitish aragonite. The patterns indicate that the whitish aragonite represents fossilized biofilms of methanotrophic consortia containing mainly archaea of the ANME-2 group and sulfate reducing bacteria, whereas the precipitation of the lucent aragonite may have lacked the immediate proximity of microorganisms during formation. By contrast, the gray micrite formed by incorporation of allochthonous organic and inorganic matter during carbonate precipitation induced by the anaerobic oxidation of methane involving ANME-1 archaea
Using technology to assess and intervene with illicit drug-using persons at risk for HIV
PURPOSE OF REVIEW: This review describes recent literature on novel ways technology is used for assessment of illicit drug use and HIV risk behaviours, suggestions for optimizing intervention acceptability, and recently completed and ongoing technology-based interventions for drug-using persons at risk for HIV and others with high rates of drug use and HIV risk behaviour. RECENT FINDINGS: Among studies (n=5) comparing technology-based to traditional assessment methods, those using Ecological Momentary Assessment (EMA) had high rates of reported drug use and high concordance with traditional assessment methods. The two recent studies assessing the acceptability of mHealth approaches overall demonstrate high interest in these approaches. Current or in-progress technology-based interventions (n=8) are delivered using mobile apps (n=5), text messaging (n=2) and computers (n=1). Most intervention studies are in progress or do not report intervention outcomes; the results from one efficacy trial showed significantly higher HIV testing rates among persons in need of drug treatment. SUMMARY: Studies are needed to continually assess technology adoption and intervention preferences among drug-using populations to ensure that interventions are appropriately matched to users. Large-scale technology-based intervention trials to assess the efficacy of these approaches, as well as the impact of individual intervention components, on drug use and other high-risk behaviours are recommended
Cumulative life course adversity, mental health, and cognition in the UK biobank
Abstract
The association between adversity and cognition varies according to the specific adversity, when the adversity was experienced, and the cognitive domains investigated. Disentangling the effect of adversity and the underlying mechanistic pathway is therefore difficult. The association between adversity (i.e., maltreatment) accumulated over the life course and cognitive flexibility, as well as two potential mediators (i.e., intra-individual variability in reaction time and depression) of this association, were investigated. Data stem from the baseline population of the UK Biobank study ( N  = 73,489, Mdn age  = 56, SD age  = 7.628, 55.740% of women). Cumulative life course adversity (specifically maltreatment) was measured with items based on the Childhood Trauma Questionnaire (CTS-5) and items adapted from the British Crime Survey. Depression was assessed with the Patient Health Questionnaire-9 (PHQ-9). Intra-individual variability in reaction time was measured with a reaction time test “snap game” and the Trail Making Test A and B were used as a measure of cognitive flexibility. A path analysis was performed on these data. Higher cumulative adverse experiences were associated with lower performance in cognitive flexibility (β = .016, p  < .001, 95% CI [0.009, 0.024]), and this effect was partly mediated by the level of depression (22.727% of the total effect of cumulative life course adversity on cognitive flexibility was mediated by depression (β = .005, p  < .001, 95% CI [0.004, 0.007])). No association between cumulative life course adverse experiences and intra-individual variability in reaction time was found, nor was any indirect association between cumulative life course adversity and performance in cognitive flexibility via intra-individual variability in reaction time. The association between cumulative life course adversity, depression, and performance in cognitive flexibility has been highlighted. In contrast, no indirect effect between cumulative life course adversity and performance in cognitive flexibility via intra-individual variability in reaction time was found, suggesting that it is not a potential mechanism underlying the association between cumulative life course adversity and executive function. </p
LGBT community, social network characteristics, and smoking behaviors in young sexual minority women.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106605/1/LGBT community, social network characteristics, and smoking behaviors in young sexual minority women.pd
Engaging youth in mHealth: what works and how can we be sure?
BACKGROUND: Youth participating in mobile health (mHealth) intervention trials often engage with the technologies [e.g., applications (app) or mobile-optimized websites] only partially, often prematurely discontinuing use altogether. Limited engagement can impact the interventions effect on behavior change and compromise researchers' ability to test and estimate the true efficacy of their interventions. While mHealth interventions have been shown to be feasible and acceptable to youth, across diverse health conditions, strategies to increase engagement have been less well studied. Specifically, within HIV prevention and care mHealth interventions, there is not consensus as to which components represent the "key ingredients" to support maximal engagement of youth. Further, successful intervention evaluation requires the ability to systematically track users' engagement with intervention components (i.e., paradata) to evaluate its effects on behavior change. METHODS: As part of the Adolescent Medicine Trials Network UNC/Emory Center for Innovative Technology (iTech) portfolio of HIV/AIDS Interventions, we present diverse strategies used across five mHealth protocols seeking to promote youth engagement, track and measure engagement through paradata, and incorporate these components into mHealth intervention evaluations. RESULTS: We describe the importance of defining and measuring engagement using case studies from iTech to illustrate how different research teams select mHealth features to promote youth engagement over time, taking into account features embedded in the technology design, key mechanisms of change and trial outcomes (e.g., HIV testing, pre-exposure prophylaxis uptake and adherence, HIV treatment adherence). Finally, we discuss how the research teams plan to evaluate engagement's role on their intervention's outcomes. CONCLUSIONS: Based on this synthesis, we discuss strategies to enhance mHealth engagement during intervention development and design, ensure its monitoring and reporting throughout the trial, and evaluate its impact on trial outcomes
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