Problematic Internet use, mental health and impulse control in an online survey of adults

Background and aims: Internet use has become a popular entertainment source and has become highly integrated into daily life. However, some people display problematic or addictive usage of the Internet. The present study attempts to fill current knowledge gaps regarding at-risk/problematic Internet use (ARPIU) and its relation to various health and functioning measures. Methods: Online survey data from 755 adults in the United States were analyzed using chi-square and ANOVAs. Results: The ARPIU group did not differ from the non-ARPIU group with respect to substance use. Individuals with ARPIU were, however, more likely to report at-risk/problematic engagement in video-game playing and gambling. Compared to the non-ARPIU group, the ARPIU group reported poorer self-control and higher levels of impulsivity and depression. Conclusions: ARPIU appears associated with other risk behaviors, particularly those that might be performed on the Internet. Future studies should examine the extent to which the Internet may promote engagement in these risk behaviors and the extent to which preventative interventions targeting better self-control or negative mood states might help a range of non-substance-related addictive behaviors

Inorganic carbon outwelling from a Mediterranean seagrass meadow using radium isotopes

Seagrass meadows are ‘blue carbon’ ecosystems widely recognised for their potential role in climate change mitigation. Previous studies have focused mainly on carbon storage within meadows and sediments. However, little is known about contribution of outwelling (i.e., lateral transport) to seagrass carbon budgets. Here, radium isotopes (223Ra and 224Ra) were used to assess dissolved inorganic carbon (DIC) and total alkalinity (TA) outwelling from a Mediterranean Posidonia oceanica meadow during early autumn. DIC outwelling was 114 ± 61 mmol m − 2 day − 1 and exceeded above-meadow CO2 outgassing (3 ± 1 mmol m − 2 day − 1). Production of DIC was uncoupled from TA and fuelled by net heterotrophy and aerobic processes within the meadow. The small export of TA (5 ± 6 mmol m−2 day − 1) implied that ∼ 90 % of outwelled DIC may return to the atmosphere as CO2 in offshore waters. Combining these fluxes with above-meadow outgassing suggested a total carbon loss that exceeded long term burial in sediments. Overall, the meadow acted as a carbon source to the atmosphere during the early autumn season. Further studies quantifying outwelling at multiple spatial and temporal scales are required to better resolve seagrass carbon budgets and their contribution to carbon sequestration

Methane emissions in seagrass meadows as a small offset to carbon sequestration

Seagrass meadows are effective carbon sinks due to high primary production and sequestration in sediments. However, methane (CH4) emissions can partially counteract their carbon sink capacity. Here, we measured diffusive sediment-water and sea-air CO2 and CH4 fluxes in a coastal embayment dominated by Posidonia oceanica in the Mediterranean Sea. High-resolution timeseries observations revealed large spatial and temporal variability in CH4 concentrations (2–36 nM). Lower sea-air CH4 emissions were observed in an area with dense seagrass meadows compared to patchy seagrass. A 6%−40% decrease of CH4 concentration in the surface water around noon indicates that photosynthesis likely limits CH4 fluxes. Sediments were the major CH4 source as implied from radon (a natural porewater tracer) observations and evidence for methanogenesis in deeper sediments. CH4 sediment-water fluxes (0.1 ± 0.1–0.4 ± 0.1 mol m−2 d−1) were higher than average sea-air CH4 emissions (0.12 ± 0.10 mol m−2 d−1), suggesting that dilution and CH4 oxidation in the water column could reduce net CH4 fluxes into the atmosphere. Overall, relatively low sea-air CH4 fluxes likely represent the net emissions from subtidal seagrass habitat not influenced by allochthonous CH4 sources. The local CH4 emissions in P. oceanica can offset less than 1% of the carbon burial in sediments (142 ± 69 g CO2eq m−2 yr−1). Combining our results with earlier observations in other seagrass meadows worldwide reveals that global CH4 emissions only offset a small fraction ( \u3c 2%) of carbon sequestration in sediments from seagrass meadows

Burkholderia multivorans septicemia in a pediatric liver transplant patient

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148247/1/ajt15065_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148247/2/ajt15065.pd

Neuroanatomical changes in white and grey matter after sleeve gastrectomy

Background: MRI studies show that obese adults have reduced grey matter (GM) and white matter (WM) tissue density as well as altered WM integrity. Bariatric surgery can lead to substantial weight loss and improvements in metabolic parameters, but it remains to be examined if it induces structural brain changes. The aim of this study was to characterize GM and WM density changes measured with MRI in a longitudinal setting following sleeve gastrectomy, and to determine whether any changes are related to inflammation and cardiometabolic blood markers. Methods: 29 participants with obesity (age: 45.9 ​± ​7.8 years) scheduled to undergo sleeve gastrectomy were recruited. High-resolution T1-weighted anatomical images were acquired 1 month prior to as well as 4 and 12 months after surgery. GM and WM densities were quantified using voxel-based morphometry (VBM). Circulating lipid profile, glucose, insulin and inflammatory markers (interleukin-6, C-reactive protein and lipopolysaccharide-binding protein) were measured at each time point. A linear mixed effect model was used to compare brain changes before and after SG, controlling for age, sex, initial BMI and diabetic status. To assess the associations between changes in adiposity, metabolism and inflammation and changes in GM or WM density, the mean GM and WM densities were extracted across all the participants using atlas-derived regions of interest, and linear mixed-effect models were used. Results: As expected, weight, BMI, waist circumference and neck circumference significantly decreased after SG compared with baseline (p ​< ​0.001 for all). A widespread increase in WM density was observed after surgery, particularly in the cerebellum, brain stem, cerebellar peduncle, cingulum, corpus callosum and corona radiata (p ​< ​0.05, after FDR correction). Significant increases in GM density were observed 4 months after SG compared to baseline in several brain regions such as the bilateral occipital cortex, temporal cortex, postcentral gyrus, cerebellum, hippocampus and insula as well as right fusiform gyrus, right parahippocampal gyrus, right lingual gyrus and right amygdala. These GM and WM increases were more pronounced and widespread after 12 months and were significantly associated with post-operative weight loss and the improvement of metabolic alterations. A linear mixed-effect model also showed associations between post-operative reductions in lipopolysaccharide-binding protein, a marker of inflammation, and increased WM density. To confirm our results, we tested whether the peak of each significant region showed BMI-related differences in an independent dataset (Human Connectome Project). We matched a group of individuals who were severely obese with a group of individuals who were lean for age, sex and ethnicity. Severe obesity was associated with reduced WM density in the brain stem and cerebellar peduncle as well as reduced GM density in cerebellum, regions that significantly changed after surgery (p ​< ​0.01 for all clusters). Conclusions: Bariatric surgery-induced weight loss and improvement in metabolic alterations is associated with widespread increases in WM and GM densities. These post-operative changes overlapped with baseline brain differences between participants who were severely obese and those who were normal-weight in a separate dataset, which may suggest a recovery of WM and GM alterations after bariatric surgery

The removal of multiplicative, systematic bias allows integration of breast cancer gene expression datasets – improving meta-analysis and prediction of prognosis

BACKGROUND: The number of gene expression studies in the public domain is rapidly increasing, representing a highly valuable resource. However, dataset-specific bias precludes meta-analysis at the raw transcript level, even when the RNA is from comparable sources and has been processed on the same microarray platform using similar protocols. Here, we demonstrate, using Affymetrix data, that much of this bias can be removed, allowing multiple datasets to be legitimately combined for meaningful meta-analyses. RESULTS: A series of validation datasets comparing breast cancer and normal breast cell lines (MCF7 and MCF10A) were generated to examine the variability between datasets generated using different amounts of starting RNA, alternative protocols, different generations of Affymetrix GeneChip or scanning hardware. We demonstrate that systematic, multiplicative biases are introduced at the RNA, hybridization and image-capture stages of a microarray experiment. Simple batch mean-centering was found to significantly reduce the level of inter-experimental variation, allowing raw transcript levels to be compared across datasets with confidence. By accounting for dataset-specific bias, we were able to assemble the largest gene expression dataset of primary breast tumours to-date (1107), from six previously published studies. Using this meta-dataset, we demonstrate that combining greater numbers of datasets or tumours leads to a greater overlap in differentially expressed genes and more accurate prognostic predictions. However, this is highly dependent upon the composition of the datasets and patient characteristics. CONCLUSION: Multiplicative, systematic biases are introduced at many stages of microarray experiments. When these are reconciled, raw data can be directly integrated from different gene expression datasets leading to new biological findings with increased statistical power

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy.

We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities