271 research outputs found
Lesser Prairie-chicken Use of Harvested Corn Fields during Fall and Winter in Southwestern Kansas
The lesser prairie-chicken (Tympanuchus pallidicinctus) has declined in numbers in Kansas primarily due to the conversion of sand sagebrush (Artemisia .filifolia) prairie to cropland. The lesser prairie-chicken in Finney County, Kansas exists primarily in large fragments of sand sagebrush prairie, and it forages during fall and winter on waste grain in harvested com (Zea mays) fields adjacent to prairie fragments. We used radio-telemetry to monitor lesser prairie chicken locations and found no significant relationship between numbers of bird locations and amounts of waste grain on the ground in harvested com fields. Even the harvested fields with the least amount of waste grain seemed to have sufficient amounts of food available for foraging lesser prairie-chicken. There appeared to be no need to develop supplemental food sources for wintering lesser prairie-chicken populations that have access to harvested fields of irrigated com in Finney County
Design and operation of automated ice-tethered profilers for real-time seawater observations in the polar oceans
An automated, easily-deployed Ice-Tethered Profiler (ITP) has been developed for deployment on perennial sea ice in polar oceans to
measure changes in upper ocean temperature and salinity in all seasons. The ITP system consists of three components: a surface
instrument that sits atop an ice floe, a weighted, plastic-jacketed wire-rope tether of arbitrary length (up to 800 m) suspended from the
surface instrument, and an instrumented underwater unit that profiles up and down the wire tether. The profiling underwater unit is
similar in shape and dimension to an ARGO float except that the float's variable-buoyancy system is replaced with a traction drive unit.
Deployment of ITPs may be conducted either from ice caps or icebreakers, utilizing a self contained tripod/winch system that requires no
power. Careful selection of an appropriate multiyear ice floe is needed to prolong the lifetime of the system (up to 3 years depending on
the profiling schedule). Shortly after deployment, each ITP begins profiling the water column at its programmed sampling interval. After
each acquired temperature and salinity profile, the underwater unit (PROCON) transfers the data and engineering files using an inductive
modem to the surface controller (SURFCON). SURFCON also accumulates battery voltages, buoy temperature, and locations from GPS at
specified intervals in status files, and queues that information for transmission at the start of each new day. At frequent intervals, an
Iridium satellite transceiver in the surface package calls and transmits queued status and CTD data files onto a WHOI logger computer,
which are subsequently processed and displayed in near-real time at http://www.whoi.edu/itp. In 2004 and 2005, three ITP prototypes
were deployed in the Arctic Ocean. Each system was programmed with accelerated sampling schedules of multiple one-way traverses per
day between 10 and 750-760 m depth in order to quickly evaluate endurance and component fatigue. Two of the ITPs are continuing to
function after more than 10 months and 1200 profiles. Larger motor currents are observed at times of fast ice floe motion when larger
wire angles develop and drag forces on the profiler are increased. The CTD profile data so far obtained document interesting spatial
variations in the major water masses of the Beaufort Gyre, show the double-diffusive thermohaline staircase that lies above the warm,
salty Atlantic layer, and many mesoscale eddys. Deployed together with CRREL Ice Mass Balance (IMB) buoys, these ITP systems also
operate as part of an Ice Based Observatory (IBO). Data returned from an array of IBOs within an Arctic Observing Network will provide
valuable real time observations, support studies of ocean processes, and facilitate numerical model initialization and validation.Funding was provided by the National Science Foundation under Contract Nos. OCE-0324233 and ARC-0519899
EUV mask reflectivity measurements with micron-scale spatial resolution
The effort to produce defect-free mask blanks for EUV lithography relies on increasing the detection sensitivity of advanced mask inspection tools, operating at several wavelengths. We describe the unique measurement capabilities of a prototype actinic (EUV wavelength) microscope that is capable of detecting small defects and reflectivity changes that occur on the scale of microns to nanometers. Types of defects: (a) Buried Substrate Defects: particles & pits (causes amplitude and/or phase variations); (b) Surface Contamination (reduces reflectivity and (possibly) contrast); (c) Damage from Inspection and Use (reduces the reflectivity of the multilayer coating). This paper presents an overview of several topics where scanning actinic inspection makes a unique contribution to EUVL research. We describe the role of actinic scanning inspection in four cases: defect repair studies; observations of laser damage; after scanning electron microscopy; and native and programmed defects
Host–symbiont combinations dictate the photo-physiological response of reef-building corals to thermal stress
High sea surface temperatures often lead to coral bleaching wherein reef-building corals lose significant numbers of their endosymbiotic dinoflagellates (Symbiodiniaceae). These increasingly frequent bleaching events often result in large scale coral mortality, thereby devasting reef systems throughout the world. The reef habitats surrounding Palau are ideal for investigating coral responses to climate perturbation, where many inshore bays are subject to higher water temperature as compared with offshore barrier reefs. We examined fourteen physiological traits in response to high temperature across various symbiotic dinoflagellates in four common Pacific coral species, Acropora muricata, Coelastrea aspera, Cyphastrea chalcidicum and Pachyseris rugosa found in both offshore and inshore habitats. Inshore corals were dominated by a single homogenous population of the stress tolerant symbiont Durusdinium trenchii, yet symbiont thermal response and physiology differed significantly across coral species. In contrast, offshore corals harbored specific species of Cladocopium spp. (ITS2 rDNA type-C) yet all experienced similar patterns of photoinactivation and symbiont loss when heated. Additionally, cell volume and light absorption properties increased in heated Cladocopium spp., leading to a greater loss in photo-regulation. While inshore coral temperature response was consistently muted relative to their offshore counterparts, high physiological variability in D. trenchii across inshore corals suggests that bleaching resilience among even the most stress tolerant symbionts is still heavily influenced by their host environment
Angiotensin receptors in GtoPdb v.2023.1
The actions of angiotensin II (Ang II) are mediated by AT1 and AT2 receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Angiotensin receptors [63, 155]), which have around 30% sequence similarity. The decapeptide angiotensin I, the octapeptide angiotensin II and the heptapeptide angiotensin III are endogenous ligands. losartan, candesartan, olmesartan, telmisartan, etc. are clinically used AT1 receptor blockers
Angiotensin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
The actions of angiotensin II (Ang II) are mediated by AT1 and AT2 receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Angiotensin receptors [61, 152]), which have around 30% sequence similarity. The decapeptide angiotensin I, the octapeptide angiotensin II and the heptapeptide angiotensin III are endogenous ligands. losartan, candesartan, telmisartan, etc. are clinically used AT1 receptor blockers
Calcium-sensing receptor antagonists abrogate airway hyperresponsiveness and inflammation in allergic asthma
Airway hyperresponsiveness and inflammation are fundamental hallmarks of allergic asthma that are accompanied by increases in certain polycations, such as eosinophil cationic protein. Levels of these cations in body fluids correlate with asthma severity. We show that polycations and elevated extracellular calcium activate the human recombinant and native calcium-sensing receptor (CaSR), leading to intracellular calcium mobilization, cyclic adenosine monophosphate breakdown, and p38 mitogen-activated protein kinase phosphorylation in airway smooth muscle (ASM) cells. These effects can be prevented by CaSR antagonists, termed calcilytics. Moreover, asthmatic patients and allergen-sensitized mice expressed more CaSR in ASMs than did their healthy counterparts. Indeed, polycations induced hyperreactivity in mouse bronchi, and this effect was prevented by calcilytics and absent in mice with CaSR ablation from ASM. Calcilytics also reduced airway hyperresponsiveness and inflammation in allergen-sensitized mice in vivo. These data show that a functional CaSR is up-regulated in asthmatic ASM and targeted by locally produced polycations to induce hyperresponsiveness and inflammation. Thus, calcilytics may represent effective asthma therapeutics
SARS-CoV-2 evolution during treatment of chronic infection
The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for virus infection through the engagement of the human ACE2 protein1 and is a major antibody target. Here we show that chronic infection with SARS-CoV-2 leads to viral evolution and reduced sensitivity to neutralizing antibodies in an immunosuppressed individual treated with convalescent plasma, by generating whole-genome ultra-deep sequences for 23 time points that span 101 days and using in vitro techniques to characterize the mutations revealed by sequencing. There was little change in the overall structure of the viral population after two courses of remdesivir during the first 57 days. However, after convalescent plasma therapy, we observed large, dynamic shifts in the viral population, with the emergence of a dominant viral strain that contained a substitution (D796H) in the S2 subunit and a deletion (ΔH69/ΔV70) in the S1 N-terminal domain of the spike protein. As passively transferred serum antibodies diminished, viruses with the escape genotype were reduced in frequency, before returning during a final, unsuccessful course of convalescent plasma treatment. In vitro, the spike double mutant bearing both ΔH69/ΔV70 and D796H conferred modestly decreased sensitivity to convalescent plasma, while maintaining infectivity levels that were similar to the wild-type virus.The spike substitution mutant D796H appeared to be the main contributor to the decreased susceptibility to neutralizing antibodies, but this mutation resulted in an infectivity defect. The spike deletion mutant ΔH69/ΔV70 had a twofold higher level of infectivity than wild-type SARS-CoV-2, possibly compensating for the reduced infectivity of the D796H mutation. These data reveal strong selection on SARS-CoV-2 during convalescent plasma therapy, which is associated with the emergence of viral variants that show evidence of reduced susceptibility to neutralizing antibodies in immunosuppressed individuals
Atypical B cells and impaired SARS-CoV-2 neutralization following heterologous vaccination in the elderly
Suboptimal responses to a primary vaccination course have been reported in the elderly, but there is little information regarding the impact of age on responses to booster third doses. Here, we show that individuals 70 years or older (median age 73, range 70-75) who received a primary two-dose schedule with AZD1222 and booster third dose with mRNA vaccine achieve significantly lower neutralizing antibody responses against SARS-CoV-2 spike pseudotyped virus compared with those younger than 70 (median age 66, range 54-69) at 1 month post booster. Impaired neutralization potency and breadth post third dose in the elderly is associated with circulating "atypical" spike-specific B cells expressing CD11c and FCRL5. However, when considering individuals who received three doses of mRNA vaccine, we did not observe differences in neutralization or enrichment in atypical B cells. This work highlights the finding that AdV and mRNA COVID-19 vaccine formats differentially instruct the memory B cell response
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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