2,234 research outputs found
RELATIONSHIP BETWEEN ATOPIC DERMATITIS AND IMMUNOGLOBULIN E
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66225/1/j.1365-4362.1976.tb00705.x.pd
Relative exposure to microplastics and prey for a pelagic forage fish
© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chavarry, J. M., Law, K. L., Barton, A. D., Bowlin, N. M., Ohman, M. D., & Choy, C. A. Relative exposure to microplastics and prey for a pelagic forage fish. Environmental Research Letters, 17(6), (2022): 064038, https://doi.org/10.1088/1748-9326/ac7060.In the global ocean, more than 380 species are known to ingest microplastics (plastic particles less than 5 mm in size), including mid-trophic forage fishes central to pelagic food webs. Trophic pathways that bioaccumulate microplastics in marine food webs remain unclear. We assess the potential for the trophic transfer of microplastics through forage fishes, which are prey for diverse predators including commercial and protected species. Here, we quantify Northern Anchovy (Engraulis mordax) exposure to microplastics relative to their natural zooplankton prey, across their vertical habitat. Microplastic and zooplankton samples were collected from the California Current Ecosystem in 2006 and 2007. We estimated the abundance of microplastics beyond the sampled size range but within anchovy feeding size ranges using global microplastic size distributions. Depth-integrated microplastics (0–30 m depth) were estimated using a depth decay model, accounting for the effects of wind-driven vertical mixing on buoyant microplastics. In this coastal upwelling biome, the median relative exposure for an anchovy that consumed prey 0.287–5 mm in size was 1 microplastic particle for every 3399 zooplankton individuals. Microplastic exposure varied, peaking within offshore habitats, during the winter, and during the day. Maximum exposure to microplastic particles relative to zooplankton prey was higher for juvenile (1:23) than adult (1:33) anchovy due to growth-associated differences in anchovy feeding. Overall, microplastic particles constituted fewer than 5% of prey-sized items available to anchovy. Microplastic exposure is likely to increase for forage fishes in the global ocean alongside declines in primary productivity, and with increased water column stratification and microplastic pollution.This work originated from the Plastic Awareness Global Initiative (PAGI) international workshop, hosted by the Center for Marine Biodiversity and Conservation (CMBC) at Scripps Institution of Oceanography at the University of California San Diego in 2018, with support from Igor Korneitchouk and the Wilsdorf Mettler Future Foundation. We thank the workshop participants for early discussions and a collaborative meeting space. We thank Kelly Lance for her illustration contributions, and the SIO Communications Office for their support. We thank Miriam Doyle and Ryan Rykaczewski for their assistance in data acquisition, and we thank Penny Dockry and Stuart Sandin of CMBC for administrative and logistical support. Julia Chavarry was supported by the San Diego Fellowship. This paper is a contribution from the California Current Ecosystem Long Term Ecological Research site, supported by the National Science Foundation
Density and mechanical properties of vertebral trabecular bone—A review
Being able to predict the mechanical properties of vertebrae in patients with osteoporosis and other relevant pathologies is essential to prevent fractures and to develop the most favorable fracture treatments. Furthermore, a reliable prediction is important for developing more patient- and pathology-specific biomaterials. A plethora of studies correlating bone density to mechanical properties has been reported; however, the results are variable, due to a variety of factors, including anatomical site and methodological differences. The aim of this study was to provide a comprehensive literature review on density and mechanical properties of human vertebral trabecular bone as well as relationships found between these properties. A literature search was performed to include studies, which investigated mechanical properties and bone density of trabecular bone. Only studies on vertebral trabecular bone tissue, reporting bone density or mechanical properties, were kept.
A large variation in reported vertebral trabecular bone densities, mechanical properties, and relationships between the two was found, as exemplified by values varying between 0.09 and 0.35 g/cm3 for the wet apparent density and from 0.1 to 976 MPa for the elastic modulus. The differences were found to reflect variations in experimental and analytical processes that had been used, including testing protocol and specimen geometry. The variability in the data decreased in studies where bone tissue testing occurred in a standardized manner (eg, the reported differences in average elastic modulus decreased from 400% to 10%). It is important to take this variability into account when analyzing the predictions found in the literature, for example, to calculate fracture risk, and it is recommended to use the models suggested in the present review to reduce data variability
Modulation of human macrophage responses to mycobacterium tuberculosis by silver nanoparticles of different size and surface modification
Exposure to silver nanoparticles (AgNP) used in consumer products carries potential health risks including increased susceptibility to infectious pathogens. Systematic assessments of antimicrobial macrophage immune responses in the context of AgNP exposure are important because uptake of AgNP by macrophages may lead to alterations of innate immune cell functions. In this study we examined the effects of exposure to AgNP with different particle sizes (20 and 110 nm diameters) and surface chemistry (citrate or polyvinlypyrrolidone capping) on cellular toxicity and innate immune responses against Mycobacterium tuberculosis (M.tb) by human monocyte-derived macrophages (MDM). Exposures of MDM to AgNP significantly reduced cellular viability, increased IL8 and decreased IL10 mRNA expression. Exposure of M.tb-infected MDM to AgNP suppressed M.tb-induced expression of IL1B, IL10, and TNFA mRNA. Furthermore, M.tb-induced IL-1β, a cytokine critical for host resistance to M.tb, was inhibited by AgNP but not by carbon black particles indicating that the observed immunosuppressive effects of AgNP are particle specific. Suppressive effects of AgNP on the M.tb-induced host immune responses were in part due to AgNP-mediated interferences with the TLR signaling pathways that culminate in the activation of the transcription factor NF-κB. AgNP exposure suppressed M.tb-induced expression of a subset of NF-κB mediated genes (CSF2, CSF3, IFNG, IL1A, IL1B, IL6, IL10, TNFA, NFKB1A). In addition, AgNP exposure increased the expression of HSPA1A mRNA and the corresponding stress-induced Hsp72 protein. Up-regulation of Hsp72 by AgNP can suppress M.tb-induced NF-κB activation and host immune responses. The observed ability of AgNP to modulate infectious pathogen-induced immune responses has important public health implications
A beta 2-Integrin/MRTF-A/SRF Pathway Regulates Dendritic Cell Gene Expression, Adhesion, and Traction Force Generation
beta 2-integrins are essential for immune system function because they mediate immune cell adhesion and signaling. Consequently, a loss of beta(2)-integrin expression or function causes the immunodeficiency disorders, Leukocyte Adhesion Deficiency (LAD) type I and III. LAD-III is caused by mutations in an important integrin regulator, kindlin-3, but exactly how kindlin-3 regulates leukocyte adhesion has remained incompletely understood. Here we demonstrate that mutation of the kindlin-3 binding site in the beta 2-integrin (TTT/AAA-beta 2-integrin knock-in mouse/KI) abolishes activation of the actin-regulated myocardin related transcription factor A/serum response factor (MRTF-A/SRF) signaling pathway in dendritic cells and MRTF-A/SRF-dependent gene expression. We show that Ras homolog gene family, member A (RhoA) activation and filamentous-actin (F-actin) polymerization is abolished in murine TTT/AAA-beta 2-integrin KI dendritic cells, which leads to a failure of MRTF-A to localize to the cell nucleus to coactivate genes together with SRF. In addition, we show that dendritic cell gene expression, adhesion and integrin-mediated traction forces on ligand coated surfaces is dependent on the MRTF-A/SRF signaling pathway. The participation of beta 2-integrin and kindlin-3-mediated cell adhesion in the regulation of the ubiquitous MRTF-A/SRF signaling pathway in immune cells may help explain the role of beta 2-integrin and kindlin-3 in integrin-mediated gene regulation and immune system function
Three-year follow-up and event rates in the international REduction of Atherothrombosis for Continued Health Registry
To determine 3-year event rates in outpatients with vascular disease enrolled in the REduction of Atherothrombosis for Continued Health (REACH) Registry. Methods and results REACH enrolled 67 888 outpatients with atherothrombosis [ established coronary artery disease (CAD), cerebrovascutar disease, or peripheral arterial disease (PAD)], or with at least three atherothrombotic risk factors, from 44 countries . Among the 55 499 patients at baseline with symptomatic disease, 39 675 were eligible for 3-year follow-up, and 32 247 had data available (81% retention rate). Among the symptomatic patients at 3 years, 92% were taking an antithrombotic agent, 91% an anti hypertensive, and 76% were on Upid- lowering therapy. For myocardial infarction (Ml)/ stroke/vascutar death, 1 - and 3-year event rates for all patients were 4.2 and 11.0%, respectively. Event rates (MI/ stroke/vascutar death) were significantly higher for patients with symptomatic disease vs. those with risk factors only at 1 year (4.7 vs. 2.3%, P < 0.001) and at 3 years (12.0 vs. 6.0%, P < 0.001). One and 3-year rates of MI /stroke/vascular cleath/ rehospitatization were 14.4 and 28.4 %, respectively, for patients with symptomatic disease. Rehospitalization for a vascular event other than Mi/ stroke/ vascular death was common at 3 years (19.0% overall; 33.6% for PAD ; 23.0% for CAD). For patients with symptomatic vascular disease in one vascular bed vs. multiple vascular beds, 3-year event rates for MI/stroke/ vascular death/ rehospitalization were 25.5 vs. 40.5% (P < 0.001). Conclusion Despite contemporary therapy, outpatients with symptomatic atherothrombotic vascular disease experience high rates of recurrent vascular events and rehospitalizations
Intra-aortic balloon counterpulsation in US and non-US centres: results of the Benchmark® Registry
Aims To examine differences in patient characteristics and outcomes in 19 636 patients enrolled in the USA and 3027 patients enrolled in other countries undergoing intra-aortic balloon pump (IABP) counterpulsation. Methods and results Indications for IABP use; a larger percentage of US patients were identified as ‘early support and stabilization for angiography or angioplasty' (21.1% US vs 11.8% non-US), and ‘pre-operative support for high-risk CABG' (15.9% vs 6.6%). A smaller percentage of US patients vs non-US patients were identified as ‘weaning from cardiopulmonary bypass' (14.3% vs 28.2%), and ‘refractory ventricular failure' (6.2% vs 9.8%). One out of five patients in both groups was listed as ‘cardiogenic shock' (18.9% US vs 20.2% non-US). All cause, risk-adjusted, in-hospital mortality (20.1% vs 28.7%; P<0.001), and mortality with IABP in place (10.8% vs 18.0%; P<0.001) were lower at US vs non-US sites. In both US and non-US institutions, IABP associated complication rates, such as IABP-related mortality (0.05% vs 0.07%), major limb ischaemia (0.9% vs 0.8%), and severe bleeding (0.9% vs 0.8%), were low. Conclusions IABP counterpulsation is deployed at an earlier clinical stage in US patients. Mortality rates are higher for non-US patients, particularly for patients with non-surgery cardiac interventions, even after adjusting for risk factors. Complication rates were low. Physicians should therefore not be reluctant to use IABP in high-risk patients undergoing cardiac procedure
Large salp bloom export from the upper ocean and benthic community response in the abyssal northeast Pacific: Day to week resolution
A large bloom of Salpa spp. in the northeastern Pacific during the spring of 2012 resulted in a major deposition of tunics and fecal pellets on the seafloor at ∼ 4000 m depth (Sta. M) over a period of 6 months. Continuous monitoring of this food pulse was recorded using autonomous instruments: sequencing sediment traps, a time‐lapse camera on the seafloor, and a bottom‐transiting vehicle measuring sediment community oxygen consumption (SCOC). These deep‐sea measurements were complemented by sampling of salps in the epipelagic zone by California Cooperative Ocean Fisheries Investigations. The particulate organic carbon (POC) flux increased sharply beginning in early March, reaching a peak of 38 mg C m−2 d−1 in mid‐April at 3400 m depth. Salp detritus started appearing in images of the seafloor taken in March and covered a daily maximum of 98% of the seafloor from late June to early July. Concurrently, the SCOC rose with increased salp deposition, reaching a high of 31 mg C m−2 d−1 in late June. A dominant megafauna species, Peniagone sp. A, increased 7‐fold in density beginning 7 weeks after the peak in salp deposition. Estimated food supply from salp detritus was 97–327% of the SCOC demand integrated over the 6‐month period starting in March 2012. Such large episodic pulses of food sustain abyssal communities over extended periods of time
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Analysis of Abrupt Transitions in Ecological Systems
The occurrence and causes of abrupt transitions, thresholds, or regime shifts between ecosystem states are of great concern and the likelihood of such transitions is increasing for many ecological systems. General understanding of abrupt transitions has been advanced by theory, but hindered by the lack of a common, accessible, and data-driven approach to characterizing them. We apply such an approach to 30–60 years of data on environmental drivers, biological responses, and associated evidence from pelagic ocean, coastal benthic, polar marine, and semi-arid grassland ecosystems. Our analyses revealed one case in which the response (krill abundance) linearly tracked abrupt changes in the driver (Pacific Decadal Oscillation), but abrupt transitions detected in the three other cases (sea cucumber abundance, penguin abundance, and black grama grass production) exhibited hysteretic relationships with drivers (wave intensity, sea-ice duration, and amounts of monsoonal rainfall, respectively) through a variety of response mechanisms. The use of a common approach across these case studies illustrates that: the utility of leading indicators is often limited and can depend on the abruptness of a transition relative to the lifespan of responsive organisms and observation intervals; information on spatiotemporal context is useful for comparing transitions; and ancillary information from associated experiments and observations aids interpretation of response-driver relationships. The understanding of abrupt transitions offered by this approach provides information that can be used to manage state changes and underscores the utility of long-term observations in multiple sentinel sites across a variety of ecosystems.Organismic and Evolutionary Biolog
Vertical distribution and diel patterns of zooplankton abundance and biomass at Conch Reef, Florida Keys (USA)
Zooplankton play an important role in the trophic dynamics of coral reef ecosystems. Detailed vertical and temporal distribution and biomass of zooplankton were evaluated at four heights off the bottom and at six times throughout the diel cycle over a coral reef in the Florida Keys (USA). Zooplankton abundance averaged 4396 ± 1949 SD individuals m−3, but temporal and spatial distributions varied for individual zooplankton taxa by time of day and by height off the bottom. Copepods comprised 93–96% of the abundance in the samples. Taxon-based zooplankton CHN values paired with abundance data were used to estimate biomass. Average daily biomass ranged from 3.1 to 21.4 mg C m−3 and differed by both height off the bottom and by time of day. While copepods were the numerically dominant organisms, their contribution to biomass was only 35% of the total zooplankton biomass. Our findings provide important support for the new emerging paradigm of how zooplankton are distributed over reefs
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