1,890 research outputs found
The lesbian, gay, bisexual and transgender community online: discussions of bullying and self-disclosure in YouTube videos
Computer-mediated communication has become a popular platform for identity construction and experimentation as well as social interaction for those who identify as lesbian, gay, bisexual or transgender (LGBT). The creation of user-generated videos has allowed content creators to share experiences on LGBT topics. With bullying becoming more common amongst LGBT youth, it is important to obtain a greater understanding of this phenomenon. In our study, we report on the analysis of 151 YouTube videos which were identified as having LGBT- and bullying-related content. The analysis reveals how content creators openly disclose personal information about themselves and their experiences in a non-anonymous rhetoric with an unknown public. These disclosures could indicate a desire to seek friendship, support and provide empathy
Evidence for guild structure in hyperdiverse mammalian communities.
43 pages : 1 map ; 26 cm.The ecological mechanisms that sustain high species richness in Neotropical bat communities have attracted research attention for several decades. Although many ecologists have studied the feeding behavior and diets of Neotropical bats on the assumption that food is a limiting resource, other resource axes that might be important for species coexistence are often ignored. Diurnal refugia, in particular, are a crucial resource for bats, many of which exhibit conspicuous morphological or behavioral adaptations to the roost environment. Here we report and analyze information about roost occupancy based on >500 field observations of Amazonian bats. Statistical analyses of these data suggest the existence of distinct groups of species roosting (1) in foliage, (2) exposed on the trunks of standing trees, (3) in cavities in standing trees, (4) in or under fallen trees, (5) beneath undercut earth banks, and (6) in arboreal insect nests; additionally, we recognize other groups that roost (7) in animal burrows, and (8) in rocks or caves. Roosting-guild membership is hypothesized to have a filtering effect on Amazonian bat community composition because some types of roosts are absent or uncommon in certain habitats. Among other applications of our results, cross-classifying bat species by trophic and roosting guilds suggests that the often-reported deficit of gleaning animalivores in secondary vegetation by comparison with primary forest might reflect habitat differences in roost availability rather than food resources. In general, ecological and evolutionary studies of Neotropical bats would be enhanced by considering both trophic- and roosting-guild membership in future analyses, but additional fieldwork will be required to determine the roosting behavior of many data-deficient species
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A Gpr120-selective agonist improves insulin resistance and chronic inflammation in obese mice.
It is well known that the ω-3 fatty acids (ω-3-FAs; also known as n-3 fatty acids) can exert potent anti-inflammatory effects. Commonly consumed as fish products, dietary supplements and pharmaceuticals, ω-3-FAs have a number of health benefits ascribed to them, including reduced plasma triglyceride levels, amelioration of atherosclerosis and increased insulin sensitivity. We reported that Gpr120 is the functional receptor for these fatty acids and that ω-3-FAs produce robust anti-inflammatory, insulin-sensitizing effects, both in vivo and in vitro, in a Gpr120-dependent manner. Indeed, genetic variants that predispose to obesity and diabetes have been described in the gene encoding GPR120 in humans (FFAR4). However, the amount of fish oils that would have to be consumed to sustain chronic agonism of Gpr120 is too high to be practical, and, thus, a high-affinity small-molecule Gpr120 agonist would be of potential clinical benefit. Accordingly, Gpr120 is a widely studied drug discovery target within the pharmaceutical industry. Gpr40 is another lipid-sensing G protein-coupled receptor, and it has been difficult to identify compounds with a high degree of selectivity for Gpr120 over Gpr40 (ref. 11). Here we report that a selective high-affinity, orally available, small-molecule Gpr120 agonist (cpdA) exerts potent anti-inflammatory effects on macrophages in vitro and in obese mice in vivo. Gpr120 agonist treatment of high-fat diet-fed obese mice causes improved glucose tolerance, decreased hyperinsulinemia, increased insulin sensitivity and decreased hepatic steatosis. This suggests that Gpr120 agonists could become new insulin-sensitizing drugs for the treatment of type 2 diabetes and other human insulin-resistant states in the future
Quantitative analysis of dipyridamole-thallium images for the detection of coronary artery disease
To determine if the detection of coronary artery disease by dipyridamole-thallium imaging is improved by 1) quantitative versus qualitative analysis, and 2) combining quantitative variables, 80 patients with chest pain (53 with and 27 without coronary artery disease) who underwent cardiac catheterization were studied. Segmental thallium initial uptake, linear clearance, mono-exponential clearance and redistribution were measured from early, intermediate and delayed images acquired in three projections. Normal values were determined from 13 other clinically normal subjects.When five segments per view were used for quantitative analysis, sensitivity and specificity were 87 and 63%, respectively, for uptake, 77 and 67% for linear clearance, 60 and 60% for monoexponential clearance and 62 and 56% for redistribution. Of the four variables, uptake and linear clearance were the most sensitive (p < 0.01) and specificity did not differ significantly. Using three segments per view, the specificity of uptake increased (p < 0.05) to 78% without a significant change in sensitivity (85%). With this approach, sensitivity and specificity did not differ from those of qualitative analysis (85 and 78%, respectively).Stepwise logistic regression analysis demonstrated that the best quantitative thallium correlate of the presence of coronary artery disease was a combination variable of “either abnormal uptake or abnormal linear clearance, or both.” Using five segments per view, the model's specificity (85%) was greater than that of uptake alone (p < 0.02), with similar sensitivity (92%). Using three segments per view, the model's specificity (93%) was greater than that of uptake alone (p < 0.05) and of qualitative analysis (p < 0.05), with similar sensitivity (85%). Compared with qualitative analysis, the diagnostic accuracy of the model was greater using either five segments (90 versus 82%, p < 0.01) or three segments (88 versus 82%, p < 0.05) per view.Quantitative analysis of dipyridamole-thallium images using single individual variables provides results comparable with those of qualitative analysis and this can be further optimized when a combination of quantitative variables is used
18F-Fluoride Positron Emission Tomographic Imaging of Penile Arteries and Erectile Dysfunction.
BACKGROUND: Fluorine-18 sodium fluoride (NaF), a bone-seeking radiopharmaceutical used to detect osseous metastases, localizes in regions of microcalcification in atherosclerosis. OBJECTIVES: To determine if atherosclerosis of penile arteries plays a role in erectile dysfunction (ED), this study analyzed NaF images in prostate cancer patients. METHODS: NaF positron emission tomography-computed tomography bone scans were evaluated in 437 prostate cancer patients (age 66.6 ± 8.7 years). Their urologic histories were reviewed for prevalent ED (diagnosed before the scan date) or incident ED (no ED at first scan, but developed during 1-year follow-up); patients with no ED (neither before the scan nor during follow-up) were included as a control group. A semicircular region of interest was set on the dorsal one-half of the penis (to avoid residual excreted activity in the urethra) on 5 contiguous slices at the base of the penis on positron emission tomography-computed tomography coronal reconstructions, and the average standardized uptake value (SUVmax) was described as NaF uptake. RESULTS: Of 437 patients, 336 (76.9%) had prevalent ED, 60 incident ED (13.7%), and 41 had no ED (9.4%). SUVmax in patients with prevalent (median 1.88; interquartile range [IQR]: 1.67 to 2.16) or incident (median 1.86; IQR: 1.72 to 2.08) ED was significantly higher than no ED (median 1.42; IQR: 1.25 to 1.54) patients (p < 0.001). After adjustment for other risk factors, the odds ratio of prevalent or incident ED was 25.2 (95% confidence interval: 9.5 to 67.0) for every 0.5-U increment in SUVmax with receptor operating characteristic area of 0.91 (95% confidence interval: 0.88 to 0.94). CONCLUSIONS: NaF uptake in penile vessels suggests that atherosclerosis is associated with ED in prostate cancer patients. The importance of NaF uptake needs to be tested in noncancer subjects and cause-effect relationship needs to be established
Gene-Expression Signature Predicts Postoperative Recurrence in Stage I Non-Small Cell Lung Cancer Patients
About 30% stage I non-small cell lung cancer (NSCLC) patients undergoing resection will recur. Robust prognostic markers are required to better manage therapy options. The purpose of this study is to develop and validate a novel gene-expression signature that can predict tumor recurrence of stage I NSCLC patients. Cox proportional hazards regression analysis was performed to identify recurrence-related genes and a partial Cox regression model was used to generate a gene signature of recurrence in the training dataset −142 stage I lung adenocarcinomas without adjunctive therapy from the Director's Challenge Consortium. Four independent validation datasets, including GSE5843, GSE8894, and two other datasets provided by Mayo Clinic and Washington University, were used to assess the prediction accuracy by calculating the correlation between risk score estimated from gene expression and real recurrence-free survival time and AUC of time-dependent ROC analysis. Pathway-based survival analyses were also performed. 104 probesets correlated with recurrence in the training dataset. They are enriched in cell adhesion, apoptosis and regulation of cell proliferation. A 51-gene expression signature was identified to distinguish patients likely to develop tumor recurrence (Dxy = −0.83, P<1e-16) and this signature was validated in four independent datasets with AUC >85%. Multiple pathways including leukocyte transendothelial migration and cell adhesion were highly correlated with recurrence-free survival. The gene signature is highly predictive of recurrence in stage I NSCLC patients, which has important prognostic and therapeutic implications for the future management of these patients
Dissecting the structural basis of MEIG1 interaction with PACRG
The product of the meiosis-expressed gene 1 (MEIG1) is found in the cell bodies of spermatocytes and recruited to the manchette, a structure unique to elongating spermatids, by Parkin co-regulated gene (PACRG). This complex is essential for targeting cargo to the manchette during sperm flagellum assembly. Here we show that MEIG1 adopts a unique fold that provides a large surface for interacting with other proteins. We mutated 12 exposed and conserved amino acids and show that four of these mutations (W50A, K57E, F66A, Y68A) dramatically reduce binding to PACRG. These four amino acids form a contiguous hydrophobic patch on one end of the protein. Furthermore, each of these four mutations diminishes the ability of MEIG1 to stabilize PACRG when expressed in bacteria. Together these studies establish the unique structure and key interaction surface of MEIG1 and provide a framework to explore how MEIG1 recruits proteins to build the sperm tail
Analysis of tumor template from multiple compartments in a blood sample provides complementary access to peripheral tumor biomarkers.
Targeted cancer therapeutics are promised to have a major impact on cancer treatment and survival. Successful application of these novel treatments requires a molecular definition of a patient\u27s disease typically achieved through the use of tissue biopsies. Alternatively, allowing longitudinal monitoring, biomarkers derived from blood, isolated either from circulating tumor cell derived DNA (ctcDNA) or circulating cell-free tumor DNA (ccfDNA) may be evaluated. In order to use blood derived templates for mutational profiling in clinical decisions, it is essential to understand the different template qualities and how they compare to biopsy derived template DNA as both blood-based templates are rare and distinct from the gold-standard. Using a next generation re-sequencing strategy, concordance of the mutational spectrum was evaluated in 32 patient-matched ctcDNA and ccfDNA templates with comparison to tissue biopsy derived DNA template. Different CTC antibody capture systems for DNA isolation from patient blood samples were also compared. Significant overlap was observed between ctcDNA, ccfDNA and tissue derived templates. Interestingly, if the results of ctcDNA and ccfDNA template sequencing were combined, productive samples showed similar detection frequency (56% vs 58%), were temporally flexible, and were complementary both to each other and the gold standard. These observations justify the use of a multiple template approach to the liquid biopsy, where germline, ctcDNA, and ccfDNA templates are employed for clinical diagnostic purposes and open a path to comprehensive blood derived biomarker access
Galaxy Zoo: Dust in Spirals
We investigate the effect of dust on spiral galaxies by measuring the
inclination-dependence of optical colours for 24,276 well-resolved SDSS
galaxies visually classified in Galaxy Zoo. We find clear trends of reddening
with inclination which imply a total extinction from face-on to edge-on of 0.7,
0.6, 0.5 and 0.4 magnitudes for the ugri passbands. We split the sample into
"bulgy" (early-type) and "disky" (late-type) spirals using the SDSS fracdeV (or
f_DeV) parameter and show that the average face-on colour of "bulgy" spirals is
redder than the average edge-on colour of "disky" spirals. This shows that the
observed optical colour of a spiral galaxy is determined almost equally by the
spiral type (via the bulge-disk ratio and stellar populations), and reddening
due to dust. We find that both luminosity and spiral type affect the total
amount of extinction, with "disky" spirals at M_r ~ -21.5 mags having the most
reddening. This decrease of reddening for the most luminous spirals has not
been observed before and may be related to their lower levels of recent star
formation. We compare our results with the latest dust attenuation models of
Tuffs et al. We find that the model reproduces the observed trends reasonably
well but overpredicts the amount of u-band attenuation in edge-on galaxies. We
end by discussing the effects of dust on large galaxy surveys and emphasize
that these effects will become important as we push to higher precision
measurements of galaxy properties and their clustering.Comment: MNRAS in press. 25 pages, 22 figures (including an abstract comparing
GZ classifications with common automated methods for selecting disk/early
type galaxies in SDSS data). v2 corrects typos found in proof
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