648 research outputs found
Effects of a series of triorganotins on ATP levels in human natural killer cells
Natural killer (NK) cells are our initial immune defense against viral infections and cancer development. Thus, agents that are able to interfere with their function increase the risk of cancer and/or infection. A series of triorganotins (trimethyltin (TMT), dimethylphenyltin (DMPT), methyldiphenyltin (MDPT), and triphenyltin (TPT)) have been shown to decrease the lytic function of human NK cells. TPT and MDPT were much more effective than DMPT or TMT at reducing lytic function. This study investigates the role that decreased ATP levels may play in decreases in the lytic function of NK cells induced by these organotins (OTs). A 24h exposure to as high as 10μM TMT caused no decrease in ATP levels even though this level of TMT caused a greater than 75% loss of lytic function. TPT at 200nM caused a decrease in ATP levels of about 20% while decreasing lytic function by greater than 85%. There was no association between ATP levels and lytic function for any of the compounds when NK cells were exposed for 1 or 24h. However, after a 48h exposure to both DMPT and TPT decreased lytic function was associated with decreased ATP levels. There was an association between decreased lytic function and decreased ATP levels after a 6-day exposure to each of the four compounds. These studies indicate that the loss of lytic function seen after 1 and 24h exposures to this series of organotins cannot be accounted for by decreases in ATP. However, after longer exposures loss of lytic function may be in part be attributable to inadequate ATP levels
Part Three: Restoring Urban Nature: Projects and Process
Part Three: Restoring Urban Nature: Projects and Process -- Restoring Urban Ecology: The New York–New Jersey Metropolitan Area Experience / Steven E. Clemants and Steven N. Handel -- Urban Watershed Management: The Milwaukee River Experience / Laurin N. Sievert -- Green Futures for Industrial Brownfields / Christopher A. De Sousa -- Ecological Citizenship: The Democratic Promise of Restoration / Andrew Light
Detailed seismic imaging of Merapi volcano, Indonesia, from local earthquake travel-time tomography
© 2019 Elsevier Ltd Mt. Merapi, located in central Java, Indonesia, is one of the most active volcanoes in the world. It has been subjected to numerous studies using a variety of methods, including tomographic imaging, in an attempt to understand the structure and dynamics of its magmatic plumbing system. Results of previous seismic tomographic studies that include Mt. Merapi poorly constrain the location of its underlying magma source due to limited data coverage. In order to comprehensively understand the internal structure and magmatism of Mt. Merapi, a project called DOMERAPI was conducted, in which 53 broadband seismic stations were deployed around Mt. Merapi and its neighbourhood for approximately 18 months, from October 2013 to April 2015. In this study, we compare Vp, Vs, and Vp/Vs tomograms constructed using data obtained from local (DOMERAPI) and regional seismic networks with those obtained without DOMERAPI data. We demonstrate that the data from the DOMERAPI seismic network are crucial for resolving key features beneath the volcano, such as high Vp/Vs ratios beneath the Merapi summit at ∼5 km and ∼15 km depths, which we interpret as shallow and intermediate magma bodies, respectively. Furthermore, west-east vertical sections across Mt. Merapi, and a “dormant” (less active) volcano, Mt. Merbabu, exhibit high Vp/Vs and low Vp/Vs ratios, respectively, directly beneath their summits. This observation likely reflects the presence (for Mt. Merapi) and absence (for Mt. Merbabu) of shallow magma bodies near the surface
PatologÃa inflamatoria ocular: coriorretinitis serpinginosa
Dentro de la patologÃa inflmatoria ocular, la coriorretinitis serpinginosa es un tipo de uveitis posterior que afecta a la coroides y al epitelio pigmentario de la retina. Es una entidad de muy baja prevalencia pero con un curso recurrente y progresivo que puede llevar a la pérdida irreversible de la agudeza visual. Presentamos dos casos con afectación inflmatoria caracterÃstica asà como el tratamiento y pronóstico con el que cursaron y se comenta la literatura más reciente respecto a las caracterÃsticas demográfias y clÃnicas de las diferentes series de casos publicados asà como una actualización terapéutica
Global airborne laser scanning data providers database (GlobALS)-A new tool for monitoring ecosystems and biodiversity
Protection and recovery of natural resource and biodiversity requires accurate monitoring at multiple scales. Airborne Laser Scanning (ALS) provides high-resolution imagery that is valuable for monitoring structural changes to vegetation, providing a reliable reference for ecological analyses and comparison purposes, especially if used in conjunction with other remote-sensing and field products. However, the potential of ALS data has not been fully exploited, due to limits in data availability and validation. To bridge this gap, the global network for airborne laser scanner data (GlobALS) has been established as a worldwide network of ALS data providers that aims at linking those interested in research and applications related to natural resources and biodiversity monitoring. The network does not collect data itself but collects metadata and facilitates networking and collaborative research amongst the end-users and data providers. This letter describes this facility, with the aim of broadening participation in GlobALS.</jats:p
Status of the X17 search in Montreal
At the Montreal Tandem accelerator, an experiment is being set up to measure
internal pair creation from the decay of nuclear excited states using a
multiwire proportional chamber and scintillator bars surrounding it from the
DAPHNE experiment. The acceptance covers a solid angle of nearly 4.
Preamplifiers and the data acquisition hardware have been designed and tested.
The water-cooled LiF target, mounted on an Al foil is in a thin carbon
fiber section of the beamline. The experiment will focus at first on a
measurement of the internal pair creation from the 18.15 MeV state of Be.
Assuming the ATOMKI evaluation of the electron-pair production rate from X17, a
Geant4 simulation predicts observation of a clear signal after about two weeks
of data taking with a 2 A proton beam. The IPC measurement could
eventually be extended to the giant dipole resonance of Be, as well as to
other nuclei, in particular to B.Comment: 5 pages, 4 figures, Proceedings contribution, TRIUMF Ariel Workshop,
May 25-27 202
Constraints on Low-Mass WIMP Interactions on 19F from PICASSO
Recent results from the PICASSO dark matter search experiment at SNOLAB are
reported. These results were obtained using a subset of 10 detectors with a
total target mass of 0.72 kg of 19F and an exposure of 114 kgd. The low
backgrounds in PICASSO allow recoil energy thresholds as low as 1.7 keV to be
obtained which results in an increased sensitivity to interactions from Weakly
Interacting Massive Particles (WIMPs) with masses below 10 GeV/c^2. No dark
matter signal was found. Best exclusion limits in the spin dependent sector
were obtained for WIMP masses of 20 GeV/c^2 with a cross section on protons of
sigma_p^SD = 0.032 pb (90% C.L.). In the spin independent sector close to the
low mass region of 7 GeV/c2 favoured by CoGeNT and DAMA/LIBRA, cross sections
larger than sigma_p^SI = 1.41x10^-4 pb (90% C.L.) are excluded.Comment: 23 pages, 7 figures, to be published in Phys. Lett.
HAPRAP: a haplotype-based iterative method for statistical fine mapping using GWAS summary statistics
Motivation
Fine mapping is a widely used approach for identifying the causal variant(s) at disease-associated loci. Standard methods (e.g. multiple regression) require individual level genotypes. Recent fine mapping methods using summary-level data require the pairwise correlation coefficients (r2
) of the variants. However, haplotypes rather than pairwise r2
, are the true biological representation of linkage disequilibrium (LD) among multiple loci. In this article, we present an empirical iterative method, HAPlotype Regional Association analysis Program (HAPRAP), that enables fine mapping using summary statistics and haplotype information from an individual-level reference panel.
Results
Simulations with individual-level genotypes show that the results of HAPRAP and multiple regression are highly consistent. In simulation with summary-level data, we demonstrate that HAPRAP is less sensitive to poor LD estimates. In a parametric simulation using Genetic Investigation of ANthropometric Traits height data, HAPRAP performs well with a small training sample size (N < 2000) while other methods become suboptimal. Moreover, HAPRAP’s performance is not affected substantially by single nucleotide polymorphisms (SNPs) with low minor allele frequencies. We applied the method to existing quantitative trait and binary outcome meta-analyses (human height, QTc interval and gallbladder disease); all previous reported association signals were replicated and two additional variants were independently associated with human height. Due to the growing availability of summary level data, the value of HAPRAP is likely to increase markedly for future analyses (e.g. functional prediction and identification of instruments for Mendelian randomization)
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