Substantial amounts of mercury (Hg) are projected to be released into Arctic watersheds as permafrost thaws amid warmer and wetter conditions. This may have far-reaching consequences because the highly toxic methylated form of Hg biomagnifies rapidly in ecosystems. However, understanding how climate change affects Hg dynamics in permafrost regions is limited due to the lack of long-term Arctic Hg records.
View Article and Find Full Text PDFPlatelets are highly reactive fragments of megakaryocytes that play a fundamental role in thrombosis and hemostasis. Predictably, all conventional anti-platelet therapies elicit bleeding, raising the question whether the thrombotic activity of platelets can be targeted separately. In this study, we describe a novel approach of inhibiting platelet activation through the use of bispecific single-chain variable fragments (bi-scFvs), termed cis-acting platelet receptor inhibitors (CAPRIs) that harness the immunoreceptor tyrosine-based inhibition motif (ITIM)-containing co-inhibitory receptor G6b-B (G6B) to suppress immunoreceptor tyrosine-based (ITAM)-containing receptor-mediated platelet activation.
View Article and Find Full Text PDFDengue, chikungunya, and Zika are arboviruses that cause 390 million infections annually. Risk factors for hospitalization are poorly understood. Communities affected by these diseases have an escalating prevalence of allergies and obesity, which are linked to immune dysfunction.
View Article and Find Full Text PDFToxic levels of trace metals from human activities accumulate in natural environments, yet these metal mixtures are rarely characterized or quantified. Metal mixtures accumulate in historically industrial urban areas and change as economies shift. Previous research has often focused on the sources and fate of a specific element, which limits our understanding of metal contaminant interactions in our environment.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2022
Uncertainty about the influence of anthropogenic radiative forcing on the position and strength of convective rainfall in the Intertropical Convergence Zone (ITCZ) inhibits our ability to project future tropical hydroclimate change in a warmer world. Paleoclimatic and modeling data inform on the timescales and mechanisms of ITCZ variability; yet a comprehensive, long-term perspective remains elusive. Here, we quantify the evolution of neotropical hydroclimate over the preindustrial past millennium (850 to 1850 CE) using a synthesis of 48 paleo-records, accounting for uncertainties in paleo-archive age models.
View Article and Find Full Text PDFContaminated legacy sediments contribute to modern pollution loadings, particularly trace metals. These contributions are challenging to quantify as metal histories reconstructed from sediment records cannot be easily divided into legacy and concurrent contamination. In particular, the contribution from re-mobilization and delivery of legacy metals stored in catchment soil, colluvial, and fluvial environments are rarely considered or quantified when interpreting sediment records.
View Article and Find Full Text PDFSerological assays have been widely employed during the coronavirus disease 2019 (COVID-19) pandemic to measure antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to track seroconversion in populations. However, currently available assays do not allow determination of neutralization capacity within the assay protocol. Furthermore, commercial serology assays have a high buy-in cost that is inaccessible for many research groups.
View Article and Find Full Text PDFGlobal climate change and human activities have significantly impacted lake ecosystems at an accelerating rate in recent decades, but the differences between the responses of lake ecosystems to these two stressors remain unclear. Thus an improved understanding of the long-term influences of climatic and anthropogenic disturbances is necessary for the management of lake ecosystems. In order to address these issues, a sedimentary record was obtained from Lake Yilong in Yunnan Province in southwestern China, where the climate and natural environment are dominated by the Indian Summer Monsoon and there is a long history of human occupation and intensive human activity.
View Article and Find Full Text PDFThe management of mosquito-borne diseases is a challenge in southern coastal Ecuador, where dengue is hyper-endemic and co-circulates with other arboviral diseases. Prior work in the region has explored social-ecological factors, dengue case data, and entomological indices. In this study, we bring together entomological and epidemiological data to describe links between social-ecological factors associated with risk of dengue transmission at the household level in Machala, Ecuador.
View Article and Find Full Text PDF() lifespan assays constitute a broadly used approach for investigating the fundamental biology of longevity. Traditional lifespan assays require labor-intensive microscopic monitoring of individual animals to evaluate life/death over a period of weeks, making large-scale high throughput studies impractical. The lifespan machine developed by Stroustrup .
View Article and Find Full Text PDFAbrupt warming events recorded in Greenland ice cores known as Dansgaard-Oeschger (DO) interstadials are linked to changes in tropical circulation during the last glacial cycle. Corresponding variations in South American summer monsoon (SASM) strength are documented, most commonly, in isotopic records from speleothems, but less is known about how these changes affected precipitation and Andean glacier mass balance. Here we present a sediment record spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes that has sufficient chronologic precision to document abrupt climatic events on a centennial-millennial time scale.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2020
Global warming due to anthropogenic factors can be amplified or dampened by natural climate oscillations, especially those involving sea surface temperatures (SSTs) in the North Atlantic which vary on a multidecadal scale (Atlantic multidecadal variability, AMV). Because the instrumental record of AMV is short, long-term behavior of AMV is unknown, but climatic teleconnections to regions beyond the North Atlantic offer the prospect of reconstructing AMV from high-resolution records elsewhere. Annually resolved titanium from an annually laminated sedimentary record from Ellesmere Island, Canada, shows that the record is strongly influenced by AMV via atmospheric circulation anomalies.
View Article and Find Full Text PDFBackground: Dengue human infection models (DHIM) have been used as a safe means to test the viability of prophylaxis and therapeutics.
Methods: A phase 1 study of 12 healthy adult volunteers using a challenge virus, DENV-1-LVHC strain 45AZ5, was performed. A dose escalating design was used to determine the safety and performance profile of the challenge virus.
The goal of the Caenorhabditis Intervention Testing Program is to identify robust and reproducible pro-longevity interventions that are efficacious across genetically diverse cohorts in the Caenorhabditis genus. The project design features multiple experimental replicates collected by three different laboratories. Our initial effort employed fully manual survival assays.
View Article and Find Full Text PDFBackground: The World Health Organization recommends intradermal (ID) administration of rabies vaccine for preexposure prophylaxis.
Methods: In a randomized trial in adults assigned to 1 of 6 treatment groups (ID vs intramuscular [IM], 2 vs 3 doses, and controls), rabies neutralizing antibody titers were measured to 1 year postvaccination.
Results: ID vaccination produced acceptable antibody levels in all subjects (2- and 3-dose groups).
Background: Dengue is a global health problem requiring an effective, safe dengue vaccine.
Methods: We report the results of a phase II, randomized, open-label, single-center trial in adults aged 18 to 45 years in the United States designed to explore the effects of the Chimeric Yellow Fever Derived Tetravalent Dengue Vaccine (CYD-TDV, Dengvaxia) when administered on its designated schedule (months 0, 6, and 12) or on an accelerated dosing schedule (months 0, 2, and 6) and/or given before, or concomitantly with, a vaccine against Japanese encephalitis (JE).
Results: Based on dengue virus serotype-specific neutralizing antibody (NAb), the accelerated dosing schedule was comparable to the 0, 6, and 12-month schedule.
Background: Chloroquine can impair the immune responses to intradermal rabies vaccination. Current guidelines recommend an extra intramuscular dose be given for postexposure prophylaxis in previously unvaccinated persons taking any antimalarial drug.
Methods: We conducted a randomized, open-label, single-site study in 103 previously unvaccinated healthy adults age ≥18 to ≤60 years old to evaluate the effects of chloroquine, atovaquone/proguanil (Malarone), and doxycycline on the antibody response to a purified chick embryo cell vaccine, given on a postexposure prophylaxis schedule.
The immunoreceptor tyrosine-based inhibition motif (ITIM)-containing receptor G6b-B is critical for platelet production and activation. Loss of G6b-B results in severe macrothrombocytopenia, myelofibrosis and aberrant platelet function in mice and humans. Using a combination of immunohistochemistry, affinity chromatography and proteomics, we identified the extracellular matrix heparan sulfate (HS) proteoglycan perlecan as a G6b-B binding partner.
View Article and Find Full Text PDFKnee Surg Sports Traumatol Arthrosc
March 2020
Purpose: Previous studies have implicated the iliotibial band and its deeper capsulo-osseous layer as key restraints against internal rotation. However, the kinematic properties of the capsulo-osseous layer, throughout knee range of motion, are not currently known. Therefore, the purpose of this research was to quantify the length changes of this structure through various degrees of knee flexion.
View Article and Find Full Text PDFThe rise in mercury concentrations in lake sediment deposited over the last ∼150 years is widely recognized to have resulted from human activity. However, few studies in the Great Lakes region have used lake sediment to reconstruct atmospheric mercury deposition on millennial time scales. Here we present a 9000-year mercury record from sediment in Copper Falls; a small closed-basin lake on the Keweenaw Peninsula.
View Article and Find Full Text PDFDue in part to the needs of the biopharmaceutical industry, there has been an increased drive to generate high quality recombinant proteins in large amounts. However, achieving high yields can be a challenge as the novelty and increased complexity of new targets often makes them 'difficult-to-express'. This study aimed to define the molecular features that restrict the production of a model 'difficult-to-express' recombinant protein, Tissue Inhibitor Metalloproteinase-3 (TIMP-3).
View Article and Find Full Text PDFPurified recombinant proteins are key reagents in academic and industrial research. The ability to make these proteins quickly often relies on the availability of higher eukaryotic cell hosts such as insect and mammalian cells where there is a very wide range of post-translational modifications, protein folding and trafficking pathways. This enables the generation of many proteins that cannot be made in microbial hosts.
View Article and Find Full Text PDFAt a storefront museum approximately 25 miles southeast of Pittsburgh, Pennsylvania, a sign reads, "Clean Air Started Here." This is not hyperbole. At the end of October 1948, the communities of Donora and Webster in Pennsylvania were visited by a smog that changed the face of environmental protection in the United States.
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