30 research outputs found
SCUBA noise alters community structure and cooperation at Pedersonâs cleaner shrimp cleaning stations
Recreational SCUBA diving is widespread and increasing on coral reefs worldwide. Standard open-circuit SCUBA equipment is inherently noisy and, by seeking out areas of high biodiversity, divers inadvertently expose reef communities to an intrusive source of anthropogenic noise. Currently, little is known about SCUBA noise as an acoustic stressor, and there is a general lack of empirical evidence on community-level impacts of anthropogenic noise on coral reefs. Here, we conducted a playback experiment on Caribbean reefs to investigate impacts of SCUBA noise on fish communities and interspecific cooperation at ecologically important cleaning stations of the Pedersonâs cleaner shrimp Ancylomenes pedersoni. When exposed to SCUBA-noise playback, the total occurrence of fishes at the cleaning stations decreased by 7%, and the community and cleaning clientele compositions were significantly altered, with 27% and 25% of monitored species being affected, respectively. Compared with ambient-sound playback, SCUBA-noise playback resulted in clients having to wait 29% longer for cleaning initiation and receiving 43% less cleaning; however, cheating, signalling, posing and time spent cleaning were not affected by SCUBA-noise playback. Our study is the first to demonstrate experimentally that SCUBA noise can have at least some negative impacts on reef organisms, confirming it as an ecologically relevant pollutant. Moreover, by establishing acoustic disturbance as a likely mechanism for known impacts of diver presence on reef animals, we also identify a potential avenue for mitigation in these valuable ecosystems.</p
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (PÂ <Â 5Â ĂÂ 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
The avidity of human IgG subclasses
The four human IgG subclasses display greater than 90% sequence homology and their production is antigen restricted, with IgG1 and IgG3 being preferentially elicited against protein antigens and IgG2 against carbohydrate antigens. Although the titre of a particular subclass is clearly important in overcoming infection, it is becoming apparent that the functional affinity (avidity) of such a response is also crucial. These studies were therefore initiated to investigate aspects of antibody avidity of the four human IgG subclasses. Utilising V region identical mouse-human IgG subclasses avidity differences were found by solid-phase avidity ELISA and biospecific interaction analysis (BIA). IgG4 was consistently of highest avidity and furthermore this reflected differences in dissociation rate constants. Following removal of the constant region such differences were abolished suggesting an involvement for the constant region in the control of human IgG subclass avidity. Serum IgG subclass avidity specific for pneumococcal polysaccharide serotypes 3, 6, 19 and 23 were measured by solid-phase avidity ELISA following pneumococcal vaccination. A complex pattern of avidity emerged with serotype 3 specific antibodies generally being of higher avidity. Significant differences were obtained comparing serum antibodies from children below 2 years of age with children more than 2 years of age. Such differences may contribute to the higher incidence of bacterial infection observed in children less than 2 years of age. Another aspect of IgG subclass avidity which has received little attention, is the control of affinity maturation. One possible area of regulation addressed in this study was the control of antibody affinity by cytokines. The effect of various cytokines on antigen specific total IgG avidity utilising solid-phase avidity assays developed throughout this thesis. Preliminary evidence presented in this thesis suggest that the cytokines IL-6, IL-10, TNF? and IFN? do not influence antibody avidity. The development of solid phase avidity ELISAs and BIA opens up an exciting area of biology and future investigations should answer many of the remaining questions concerning human IgG subclass avidity
Transcription of Ig Germline Genes in Single Human B Cells and the Role of Cytokines in Isotype Determination
Role of IgE receptors in IgE antibody-dependent cytotoxicity and phagocytosis of ovarian tumor cells by human monocytic cells
Tracing Compartmentalized NADPH Metabolism in the Cytosol and Mitochondria of Mammalian Cells
Eukaryotic cells compartmentalize biochemical processes in different organelles, often relying on metabolic cycles to shuttle reducing equivalents across intracellular membranes. NADPH serves as the electron carrier for the maintenance of redox homeostasis and reductive biosynthesis, with separate cytosolic and mitochondrial pools providing reducing power in each respective location. This cellular organization is critical for numerous functions but complicates analysis of metabolic pathways using available methods. Here we develop an approach to resolve NADP(H)-dependent pathways present within both the cytosol and the mitochondria. By tracing hydrogen in compartmentalized reactions that use NADPH as a cofactor, including the production of 2-hydroxyglutarate by mutant isocitrate dehydrogenase enzymes, we can observe metabolic pathway activity in these distinct cellular compartments. Using this system we determine the direction of serine/glycine interconversion within the mitochondria and cytosol, highlighting the ability of this approach to resolve compartmentalized reactions in intact cells.National Institutes of Health (U.S.) (NIH grant P30CA147882)National Institutes of Health (U.S.) (NIH grant U54- CA121852-09)National Institutes of Health (U.S.) (NIH grant R01CA168653)David H. Koch Institute for Integrative Cancer Research at MIT (Koch Institute/DFHCC Bridge Project)David H. Koch Institute for Integrative Cancer Research at MIT (Koch Institute Frontier Research)Burroughs Wellcome FundDamon Runyon Cancer Research FoundationKathy and Curt Marble Cancer Research FundAmerican Cancer Society (grant IRG #70-002)United States. Department of Defense (DOD grant W81XWH-13-1-0105)University of California, San Diego (University of California Cancer Research Coordinating Committee grant)Searle Scholars Program (Award
TNFR-Associated Factor Family Protein Expression in Normal Tissues and Lymphoid Malignancies
Paula McCloskeyâ in Loveless, N.S. Contemporary Mamactivist Artists: A Forum on Maternal Activist Art for the Studies in the Maternal Special Issue on The Everyday Maternal Practice: Activist Structures in Creative Work, Summer 2016
This special forum for Studies in the Maternal asks fourteen activist-mother-artists, or âmamactivistsâ, to respond to the following questions: (1) When and why did you start making activist/political work on the maternal? (2) What reception/reaction did you receive for the work? (3) What is the latest activist/political work you have made on the maternal? (4) What shifts do you see from this first work to this last work? and (5) Why is the maternal, in your opinion, important to activist, engaged, political art today? Responses highlight a range of geographic and cultural perspectives, as well as artistic strategies. One commonality between them is that they take the maternal not as a biological facticity, but a rich feminist site of political intervention.N/