358 research outputs found
Eclipsing binary and white dwarf features associated with K2 target EPIC251248385
White dwarfs, remnants of Sun-like stars which have completed their evolution, are one of the most common types of stars in space. Despite this, very few white dwarfs have been observed in transiting or eclipsing systems, and only two planetary systems around white dwarfs are currently known, thus motivating a search for white dwarfs with transits or eclipses as seen by the Kepler telescope. A systematic search of K2 white dwarf targets revealed one candidate with regular eclipses, but additional research was necessary to confirm the transits and white dwarf signal were coming from the same astrophysical source. The software package PyKe was utilized to adjust the light curve aperture, and perform principal component analysis which revealed that the transits were originating from a single pixel. Generating a new lightcurve from this pixel revealed the absolute transit depth, which was unconstrained previously. Ten additional images taken with the 2m LCOGT telescope revealed that a potential target star in the single Kepler pixel was actually a cluster of three stars, but no clear transits were seen from any of the potential target stars in the followup images. Additionally, analysis of transit depths in the single pixel light curve and additional investigation of nearby bright sources supported the hypothesis that the transits were more likely to be coming from the white dwarf rather than the two other sources. However, the transit duration and shape appear atypical for white dwarf systems. Thus, despite determining the potential sources and relative sizes for the potential eclipsing white dwarf candidate, or whether the eclipses come from the white dwarf target cannot be confirmed without additional data.https://iopscience.iop.org/article/10.3847/2515-5172/ab5861Published versio
Transnuclear CD8 T cells specific for the immunodominant epitope Gra6 lower acute-phase Toxoplasma gondii burden.
We generated a CD8 T-cell receptor (TCR) transnuclear (TN) mouse specific to the Ld -restricted immunodominant epitope of GRA6 from Toxoplasma gondii as a source of cells to facilitate further investigation into the CD8 T-cell-mediated response against this pathogen. The TN T cells bound Ld -Gra6 tetramer and proliferated upon unspecific and peptide-specific stimulation. The TCR beta sequence of the Gra6-specific TN CD8 T cells is identical in its V- and J-region to the TCR-β harboured by a hybridoma line generated in response to Gra6 peptide. Adoptively transferred Gra6 TN CD8 T cells proliferated upon Toxoplasma infection in vivo and exhibited an activated phenotype similar to host CD8 T cells specific to Gra6. The brain of Toxoplasma-infected mice carried Gra6 TN cells already at day 8 post-infection. Both Gra6 TN mice as well as adoptively transferred Gra6 TN cells were able to significantly reduce the parasite burden in the acute phase of Toxoplasma infection. Overall, the Gra6 TN mouse represents a functional tool to study the protective and immunodominant specific CD8 T-cell response to Toxoplasma in both the acute and the chronic phases of infection
Recommended from our members
Diet quality and its relationship with central obesity among Mexican Americans: findings from National Health and Nutrition Examination Survey (NHANES) 1999-2012.
ObjectiveUsing the Healthy Eating Index-2010 (HEI-2010), the present study aimed to examine diet quality and the impact of overall diet quality and its components on central obesity among Mexican-American men and women.DesignCross-sectional data from NHANES 1999-2012 were used. The HEI-2010 data, including twelve components for a total score of 100, were collected with a 24 h recall interview. Central obesity was defined as a waist circumference of ≥88 cm for women and ≥102 cm for men. Weighted logistic regressions were performed to assess associations between HEI-2010 scores and central obesity.SettingNational Health and Nutrition Examination Survey (NHANES) 1999-2012.SubjectsA total of 6847 Mexican Americans aged ≥20 years with reliable dietary recall status and non-pregnancy status.ResultsHigher HEI-2010 total score was associated with lower odds of central obesity in Mexican-American men (OR; 95 % CI=0·98; 0·98, 1·00). Among all Mexican Americans, one-unit higher score of total fruit and sodium (i.e. lower level of intake) was associated with 4 % (0·96; 0·93, 0·99) and 2 % (0·98; 0·96, 0·99) lower odds of central obesity, respectively. However, a higher total proteins score was associated with higher odds of central obesity (1·08; 1·00, 1·16). In gender-specific analyses, a higher whole fruit or sodium score was inversely associated with central obesity in men but not in women.ConclusionsHEI-2010 scores of total fruit and sodium were inversely associated with central obesity among all Mexican Americans. However, total proteins score and central obesity was positively associated. In Mexican-American men, HEI-2010 total and whole fruit scores were inversely associated with central obesity
Role of Age and Acculturation in Diet Quality Among Mexican Americans - Findings From the National Health and Nutrition Examination Survey, 1999-2012.
Age and acculturation may play a role in diet quality among Mexican Americans. This study examined diet quality in Mexican Americans by age and whether acculturation influences diet quality across different age groups, using data from the National Health and Nutrition Examination Survey (NHANES). Diet quality, measured by the Healthy Eating Index 2010, improved with age except in categories of dairy, sodium, and refined grains. More acculturation was associated with lower scores in overall diet quality and categories of vegetables, fruits, and sodium and empty calories across almost all ages, but higher scores in grain categories, especially in younger groups. A diet rich in fruits and vegetables but low in fat and sodium should be promoted among more acculturated Mexican Americans, and whole-grain foods should be promoted among young but less acculturated Mexican Americans
Recommended from our members
Social support modifies the negative effects of acculturation on obesity and central obesity in Mexican men.
Background: This study examined the moderating role of social support in the acculturation-obesity/central obesity relationship in Mexican American (MA) men and women. Methods: Data from NHANES 1999-2008 were used. Acculturation derived from language use, country of birth and length of residence in the U.S. Social support assessed emotional and financial support. BMI (≥30) and waist circumference (≥88 cm for women; ≥102 cm for men) measured obesity and central obesity, respectively. Weighted multivariate logistic regression models were used to describe associations. Results: Compared to less acculturation, more acculturation was associated with higher odds of obesity (ORs 2.48; 95% CI 1.06-5.83) and central obesity (2.90; 1.39-6.08) among MA men with low/no social support, but not among MA men reporting high social support. The modifying effects was not observed among women. Conclusion: Higher amounts of social support appeared to attenuate the risk of obesity/central obesity associated with acculturation. Interventions enhancing social support maybe effective among acculturated MAs, particularly among men
O-mannosyl phosphorylation of alpha-dystroglycan is required for laminin binding.
Alpha-dystroglycan (alpha-DG) is a cell-surface glycoprotein that acts as a receptor for both extracellular matrix proteins containing laminin-G domains and certain arenaviruses. Receptor binding is thought to be mediated by a posttranslational modification, and defective binding with laminin underlies a subclass of congenital muscular dystrophy. Using mass spectrometry- and nuclear magnetic resonance (NMR)-based structural analyses, we identified a phosphorylated O-mannosyl glycan on the mucin-like domain of recombinant alpha-DG, which was required for laminin binding. We demonstrated that patients with muscle-eye-brain disease and Fukuyama congenital muscular dystrophy, as well as mice with myodystrophy, commonly have defects in a postphosphoryl modification of this phosphorylated O-linked mannose, and that this modification is mediated by the like-acetylglucosaminyltransferase (LARGE) protein. These findings expand our understanding of the mechanisms that underlie congenital muscular dystrophy
Recent Shifts in the Occurrence, Cause, and Magnitude of Animal Mass Mortality Events
Mass mortality events (MMEs) are rapidly occurring catastrophic demographic events that punctuate background mortality levels. Individual MMEs are staggering in their observed magnitude: re- moving more than 90% of a population, resulting in the death of more than a billion individuals, or producing 700 million tons of dead biomass in a single event. Despite extensive documentation of individual MMEs, we have no understanding of the major features characterizing the occurrence and magnitude of MMEs, their causes, or trends through time. Thus, no framework exists for contextualizing MMEs in the wake of ongoing global and regional perturbations to natural systems. Here we present an analysis of 727 published MMEs from across the globe, affecting 2,407 animal populations. We show that the magnitude of MMEs has been intensifying for birds, fishes, and marine invertebrates; invariant for mammals; and decreasing for reptiles and amphibians. These shifts in magnitude proved robust when we accounted for an increase in the occurrence of MMEs since 1940. However, it remains unclear whether the increase in the occurrence of MMEs represents a true pattern or simply a perceived increase. Regardless, the increase in MMEs appears to be associated with a rise in disease emergence, biotoxicity, and events produced by multiple interacting stressors, yet temporal trends in MME causes varied among taxa and may be associated with increased de- tectability. In addition, MMEs with the largest magnitudes were those that resulted from multiple stressors, starvation, and disease. These results advance our understanding of rare demographic processes and their relationship to global and regional perturba- tions to natural systems
ERRγ enhances cardiac maturation with T-tubule formation in human iPSC-derived cardiomyocytes
ヒトのiPS細胞から新生児レベルまで成熟した心筋細胞を作製する. 京都大学プレスリリース. 2021-06-21.Lowering the cost of heart cell therapies. 京都大学プレスリリース. 2021-06-21.One of the earliest maturation steps in cardiomyocytes (CMs) is the sarcomere protein isoform switch between TNNI1 and TNNI3 (fetal and neonatal/adult troponin I). Here, we generate human induced pluripotent stem cells (hiPSCs) carrying a TNNI1[EmGFP] and TNNI3[mCherry] double reporter to monitor and isolate mature sub-populations during cardiac differentiation. Extensive drug screening identifies two compounds, an estrogen-related receptor gamma (ERRγ) agonist and an S-phase kinase-associated protein 2 inhibitor, that enhances cardiac maturation and a significant change to TNNI3 expression. Expression, morphological, functional, and molecular analyses indicate that hiPSC-CMs treated with the ERRγ agonist show a larger cell size, longer sarcomere length, the presence of transverse tubules, and enhanced metabolic function and contractile and electrical properties. Here, we show that ERRγ-treated hiPSC-CMs have a mature cellular property consistent with neonatal CMs and are useful for disease modeling and regenerative medicine
Physiological IRE-1-XBP-1 and PEK-1 Signaling in Caenorhabditis elegans Larval Development and Immunity
Endoplasmic reticulum (ER) stress activates the Unfolded Protein Response, a compensatory signaling response that is mediated by the IRE-1, PERK/PEK-1, and ATF-6 pathways in metazoans. Genetic studies have implicated roles for UPR signaling in animal development and disease, but the function of the UPR under physiological conditions, in the absence of chemical agents administered to induce ER stress, is not well understood. Here, we show that in Caenorhabditis elegans XBP-1 deficiency results in constitutive ER stress, reflected by increased basal levels of IRE-1 and PEK-1 activity under physiological conditions. We define a dynamic, temperature-dependent requirement for XBP-1 and PEK-1 activities that increases with immune activation and at elevated physiological temperatures in C. elegans. Our data suggest that the negative feedback loops involving the activation of IRE-1-XBP-1 and PEK-1 pathways serve essential roles, not only at the extremes of ER stress, but also in the maintenance of ER homeostasis under physiological conditions.National Institutes of Health (U.S.) (grant R01-GM084477
The ASTRO-H X-ray Observatory
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly
successful X-ray missions initiated by the Institute of Space and Astronautical
Science (ISAS). ASTRO-H will investigate the physics of the high-energy
universe via a suite of four instruments, covering a very wide energy range,
from 0.3 keV to 600 keV. These instruments include a high-resolution,
high-throughput spectrometer sensitive over 0.3-2 keV with high spectral
resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in
the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers
covering 5-80 keV, located in the focal plane of multilayer-coated, focusing
hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12
keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and
a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the
40-600 keV band. The simultaneous broad bandpass, coupled with high spectral
resolution, will enable the pursuit of a wide variety of important science
themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical
Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to
Gamma Ray
- …