136 research outputs found

    Immune dysfunction and neuroinflammation in autism spectrum disorder

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    Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder with a complex pathogenesis. Many studies over the last four decades have recognized altered immune responses among individuals diagnosed with ASD. The purpose of this critical and comprehensive review is to examine the hypothesis that immune dysfunction is frequently present in those with ASD. It was found that often individuals diagnosed with ASD have alterations in immune cells such as T cells, B cells, monocytes, natural killer cells, and dendritic cells. Also, many individuals diagnosed with ASD have alterations in immunoglobulins and increased autoantibodies. Finally, a significant portion of individuals diagnosed with ASD have elevated peripheral cytokines and chemokines and associated neuroinflammation. In conclusion, immune dysregulation and inflammation are important components in the diagnosis and treatment of ASD

    Developmental neurotoxicants and the vulnerable male brain: a systematic review of suspected neurotoxicants that disproportionally affect males

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    The prevalence of neurodevelopmental disorders (NDs), including autism spectrum disorder, attention‑deficit/hyperactivity disorder, tic disorder, obsessive‑compulsive disorder, and emotional disturbances, has increased notably in the past few decades. To date, debate continues as to the origins of NDs. Increases in widespread exposure to and bioaccumulation of chemical neurotoxicants have paralleled the upsurge in NDs, and are suggested to be causal agents for NDs. One consistent aspect of NDs is the male preponderance. This review considers the issue of male preponderance by reviewing the gender‑specific neurotoxic effects of recognized neurotoxicant chemicals to assess their possible etiology in NDs. This investigation consisted of a systematic literature review of original studies published from 1970-2016 on suspected neurotoxicants, to examine whether they have a disproportionate adverse effect based on gender. Based on that review, the neurotoxicants exhibiting consistent gender‑specific effects, with exposed males being more affected (than similarly exposed females), were: lead, Thimerosal/ethylmercury, some organochlorine pesticides (e.g., dieldrin, endosulfan, and heptachlor), and air pollution. The next group identified were neurotoxicants exhibiting gender‑specific neurotoxic effects, with males being somewhat (but not consistently) more affected than females: mercury vapor, polychlorinated biphenyls (PCBs), and organophosphate pesticides. Finally, there was a group of studies in which the neurotoxicants exhibited apparent gender‑related neurotoxic effects but failed to show whether exposed males were consistently more affected than females: inorganic mercury salts, methylmercury species, and certain endocrine disruptors (e.g., phthalates and BPA). The overall conclusion from the studies reviewed was that the brain in males is more vulnerable to many toxic exposures than it is in females. Evidence suggests that the reasons for the male brain being more vulnerable include: (1) greater glutathione availability in females; (2) greater sulfate‑based detoxification capacity in females; (3) potentiating effects of co‑exposure to neurotoxicants and testosterone; (4) greater neuroinflammatory response in males; (5) reduced vulnerability to oxidative stress in females; and (6) neuroprotective effects of female hormones (estrogen and progesterone), especially in the reduction of inflammation and oxidative stress

    Life on the ice-edge: Paleoenvironmental significance of the radiolarian species Amphimelissa setosa in the northern hemisphere

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    The high-latitude Northern Hemisphere is a key region in the global climate balance. Variations in sea-ice extent affect biological productivity, CO2 exchange and carbon drawdown. Marine proxies indicative of proximity of the ice-marginal zone are therefore essential to understand these processes. Amphimelissa setosa is nowadays a dominant radiolarian species in the Arctic basin and very abundant in the high-latitude North Atlantic. This species, now absent from the North Pacific, has been widely used as a qualitative proxy of modern and past environmental conditions in the high-latitude Northern Hemisphere. Using our new and published data on the distribution of A. setosa in plankton, sediment trap, surface sediment and downcore samples, we provide a quantitative ecological context for the occurrence of this species. We find that the optimal depth and season of A. setosa in the modern North Atlantic and the Chukchi Sea are 160 m and the late boreal summer/early fall (August–October), respectively. A regression model combining environmental variables (temperature, salinity, silicate and chlorophyll-a concentrations, apparent oxygen utilization, sea-ice) at that season and depth, are able to explain 43% of the distribution of this species in surface sediments. Based on these new findings, we conclude that the presence of A. setosa in surface sediments is closely related to high primary production in the proximity of the sea-ice and areas of ice rafting. The onset of this species started at ca. 1.5 Ma in the North Pacific, linked to a gradual cooling, increased silica availability and southward advance of the ice-margins since the Early Pleistocene. Amphimelissa setosa’s decline in this region was likely caused by the development of a quasi-permanent halocline, perennial sea-ice and depletion of silica during marine isotope stage 4. In the high-latitude North Atlantic, the relative abundance of A. setosa appears to be related to cooling and supply of dissolved silica from the continent during ice-rafting events. The comprehensive approach taken in this study suggest that A. setosa is a useful proxy to explore past variations in the ice-cover in the high-latitude Northern Hemisphere.Shirshov Institute of Oceanology | Ref. 0149-2019-000

    A persistent Norwegian Atlantic Current through the Pleistocene glacials

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    Changes in ocean‐circulation regimes in the northern North Atlantic and the Nordic Seas may affect not only the Arctic but potentially hemispheric or even global climate. Therefore, unraveling the long‐term evolution of the North Atlantic Current‐Norwegian Atlantic Current system through the Pleistocene glaciations could yield useful information and climatological context for understanding contemporary changes. In this work, ~50,000 km2 of 3‐D seismic reflection data are used to investigate the Pleistocene stratigraphy for evidence of paleo‐oceanographic regimes on the mid‐Norwegian margin since 2.58 Ma. Across 33 semicontinuous regional paleo‐seafloor surfaces ~17,500 iceberg scours have been mapped. This mapping greatly expands our spatiotemporal understanding of currents and iceberg presence in the eastern Nordic Seas. The scours display a dominant southwest‐northeast trend that complements previous sedimentological and numerical modeling studies that suggest northward‐flowing currents in the Norwegian Sea during the Pleistocene. This paleo‐oceanographic study suggests that through many of the Pleistocene glaciations, the location of surface ocean currents in the Norwegian Sea and, by extension, the eastern North Atlantic, were broadly similar to the present

    Expedition 306 summary

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    The overall aim of the North Atlantic paleoceanography study of Integrated Ocean Drilling Program Expedition 306 is to place late Neogene–Quaternary climate proxies in the North Atlantic into a chronology based on a combination of geomagnetic paleointensity, stable isotope, and detrital layer stratigraphies, and in so doing generate integrated North Atlantic millennial-scale stratigraphies for the last few million years. To reach this aim, complete sedimentary sections were drilled by multiple advanced piston coring directly south of the central Atlantic “ice-rafted debris belt” and on the southern Gardar Drift. In addition to the North Atlantic paleoceanography study, a borehole observatory was successfully installed in a new ~180 m deep hole close to Ocean Drilling Program Site 642, consisting of a circulation obviation retrofit kit to seal the borehole from the overlying ocean, a thermistor string, and a data logger to document and monitor bottom water temperature variations through time

    Pastoral Herding Strategies and Governmental Management Objectives: Predation Compensation as a Risk Buffering Strategy in the Saami Reindeer Husbandry

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    Previously it has been found that an important risk buffering strategy in the Saami reindeer husbandry in Norway is the accumulation of large herds of reindeer as this increases long-term household viability. Nevertheless, few studies have investigated how official policies, such as economic compensation for livestock losses, can influence pastoral strategies. This study investigated the effect of received predation compensation on individual husbandry units’ future herd size. The main finding in this study is that predation compensation had a positive effect on husbandry units’ future herd size. The effect of predation compensation, however, was nonlinear in some years, indicating that predation compensation had a positive effect on future herd size only up to a certain threshold whereby adding additional predation compensation had little effect on future herd size. More importantly, the effect of predation compensation was positive after controlling for reindeer density, indicating that for a given reindeer density husbandry units receiving more predation compensation performed better (measured as the size of future herds) compared to husbandry units receiving less compensation

    Use of nanomaterials in the pretreatment of water samples for environmental analysis

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    The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

    Big data for bipolar disorder

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