A5028438229- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Glycosylation and Glycoproteins Research
- Particle physics theoretical and experimental studies
- Bacteriophages and microbial interactions
- Bacterial Genetics and Biotechnology
- Monoclonal and Polyclonal Antibodies Research
- SARS-CoV-2 and COVID-19 Research
- SARS-CoV-2 detection and testing
- RNA and protein synthesis mechanisms
- Carbohydrate Chemistry and Synthesis
- COVID-19 Clinical Research Studies
- Superconducting and THz Device Technology
- Astronomy and Astrophysical Research
- Relativity and Gravitational Theory
- COVID-19 diagnosis using AI
- Computational Physics and Python Applications
- Scientific Research and Discoveries
- Viral gastroenteritis research and epidemiology
- CRISPR and Genetic Engineering
- Photocathodes and Microchannel Plates
- Neutrino Physics Research
Stanford University
2020-2023
Cornell University
2013-2020
University of Pittsburgh
2014-2015
Carnegie Mellon University
2009-2014
National Institute of Technology Tiruchirappalli
2012
Bielefeld University
2008-2010
University of Florida
2005-2008
Indian Institute of Science Bangalore
2001
In this letter, 21 cm intensity maps acquired at the Green Bank Telescope are cross-correlated with large-scale structure traced by galaxies in WiggleZ Dark Energy Survey. The data span redshift range 0.6 < z 1 over two fields totaling ~41 deg. sq. and 190 hours of radio integration time. cross-correlation constrains Omega_HI b_HI r = [0.43 \pm 0.07 (stat.) 0.04(sys.)] x 10^-3, where is neutral hydrogen HI fraction, galaxy-hydrogen correlation coefficient, bias parameter. This most...
Abstract The large-scale distribution of neutral hydrogen in the Universe will be luminous through its 21 cm emission. Here, for first time, we use auto-power spectrum intensity fluctuations to constrain at z ∼ 0.8. Our data were acquired with Green Bank Telescope and span redshift range 0.6 &lt; 1 over two fields totalling ≈41 deg2 190 h radio integration time. dominant synchrotron foregrounds exceed signal by ∼103, but have fewer degrees freedom can removed efficiently. Even presence...
Abstract The emerging discipline of bacterial glycoengineering has made it possible to produce designer glycans and glycoconjugates for use as vaccines therapeutics. Unfortunately, cell-based production homogeneous glycoproteins remains a significant challenge due cell viability constraints the inability control glycosylation components at precise ratios in vivo. To address these challenges, we describe novel cell-free glycoprotein synthesis (CFGpS) technology that seamlessly integrates...
We present first results from the SCI-HI experiment, which we used to measure all-sky-averaged 21 cm brightness temperature in redshift range 14.8 < z 22.7. The instrument consists of a single broadband sub-wavelength size antenna and sampling system for real-time data processing recording. Preliminary observations were completed 2013 June at Isla Guadalupe, Mexican biosphere reserve located Pacific Ocean. was cleaned excise channels contaminated by radio frequency interference, response...
Glycosylation plays important roles in cellular function and endows protein therapeutics with beneficial properties. However, constructing biosynthetic pathways to study engineer precise glycan structures on proteins remains a bottleneck. Here, we report modular, versatile cell-free platform for glycosylation pathway assembly by rapid vitro mixing expression (GlycoPRIME). In GlycoPRIME, are assembled mixing-and-matching synthesized glycosyltransferases that can elaborate glucose primer...
Abstract Protein glycosylation, or the attachment of sugar moieties (glycans) to proteins, is important for protein stability, activity, and immunogenicity. However, understanding roles regulations site‐specific glycosylation events remains a significant challenge due several technological limitations. These limitations include lack available tools biochemical characterization enzymes involved in glycosylation. A particular synthesis oligosaccharyltransferases (OSTs), which catalyze glycans...
Abstract Patients with COVID-19 shed SARS-CoV-2 RNA in stool, sometimes well after their respiratory infection has cleared. This may be significant for patient health, epidemiology, and diagnosis. However, methods to preserve extract quantify viral are not standardized. We test the performance of three preservative approaches at yielding detectable RNA: OMNIgene-GUT kit, Zymo DNA/RNA shield most commonly applied, storage without preservative. these combination extraction kits: QIAamp Viral...
Abstract The central enzyme in the Campylobacter jejuni asparagine-linked glycosylation pathway is oligosaccharyltransferase (OST), PglB, which transfers preassembled glycans to specific asparagine residues target proteins. While C. PglB ( Cj PglB) can transfer many diverse glycan structures, acceptor sites that it recognizes are restricted predominantly those having a negatively charged residue −2 position relative asparagine. Here, we investigated acceptor-site preferences for 23 homologs...
We investigate the effects of weakly-interacting massive particle (WIMP) dark matter annihilation on formation Population III.1 stars, which are theorized to form from collapse gas cores at centers minihalos. consider relative importance cooling due baryonic radiative processes and heating WIMP annihilation. analyze profiles several halos formed in cosmological-scale numerical simulations. The rate depends sensitively density profile, we approximate with a power law rho_chi ~ r^{-alpha_chi},...
If dark matter is made up of Weakly Interacting Massive Particles, the annihilation these particles in halos results energy being released, some which absorbed by gas, causing partial ionization and heating. Dark may result gas heating at high redshifts, even before formation first stars. It shown that early a transfer power to higher multipoles large angle CMB polarization spectra. Future experiments be able place constraints on certain light models. We also investigate effect expected H21...
We present new predictions for temperature (on small angular scales) and polarization large CMB anisotropies induced during the epoch of reionization (EoR). Using a novel method calibrated from Radiation-Hydrodynamic simulations we model EoR in volumes (L >~ 2 Gpc/h) context galactic reionization. find that contribution to kinetic Sunyaev- Zel'dovich power spectrum (patchy kSZ) ranges between ~0.6 - 2.8 muK^2 at ell = 3000, parameter space explored. These patchy kSZ spectra are calculated 15...
We present predictions for the 21 cm brightness temperature power spectrum during Epoch of Reionization (EoR). discuss implications "light cone" effect, which incorporates evolution neutral hydrogen fraction and along line sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model density field signal in large volumes (L = 2 Gpc h−1). The inclusion light cone effect leads to relative decrease about 50% on all scales. also find that is more prominent at...
Radio observations of the Ursa Major II dwarf spheroidal galaxy obtained using Green Bank Telescope are used to place bounds on WIMP dark matter properties. Dark annihilation releases energy in form charged particles which emit synchrotron radiation magnetic field galaxy. We compute expected intensity from various primary channels. The predicted is sensitive distribution halo, diffusion coefficient D_0, strength B, particle mass m_\chi, rate <\sigma v>, and channel. Limits D_0 for e^+ e^-,...
We examine the importance of baryonic feedback effects on matter power spectrum small scales, and implications for precise measurement neutrino masses through gravitational weak lensing. Planned large galaxy surveys such as Large Synoptic Sky Telescope (LSST) Euclid are expected to measure sum extremely high precision, sufficient detect non-zero even in minimal mass normal hierarchy. show that lensing galaxies while being a very good probe masses, is sensitive processes. use publicly...
We prove that a flow of cold collisionless particles from all directions in and out region necessarily forms caustic. A corollary is that, dark matter cosmology, galactic halos have inner caustics addition to the more obvious outer caustics. The are fold catastrophes located on topological spheres surrounding galaxy. To obtain catastrophe structure caustics, we simulate infall fixed gravitational potential. depends angular momentum distribution infalling particles. confirm previous result...
Microbial source tracking (MST) identifies sources of fecal contamination in the environment using host-associated markers. While there are numerous bacterial MST markers that can be used herein, few such viral Here, we designed and tested novel based on tomato brown rugose fruit virus (ToBRFV) genomes. We assembled eight nearly complete genomes ToBRFV from wastewater stool samples San Francisco Bay Area United States. Next, developed two probe-based reverse transcription-PCR (RT-PCR) assays...
The annihilation of dark matter particles releases energy, ionizing some the gas in Universe. We investigate effect halos on reionization. show that depends assumed density profile, particle mass, and minimum halo mass. For Navarro-Frenk-White typical WIMPs, we find to be quite small. However, light candidates MeV range can contribute significantly reionization make an important contribution measured optical depth. This may used constrain models. also study varying profile
We use cosmic microwave background data from the WMAP, SPT, BICEP, and QUaD experiments to obtain constraints on dark matter particle mass ${m}_{\ensuremath{\chi}}$, show that combined requires ${m}_{\ensuremath{\chi}}>7.6\text{ }\text{ }\mathrm{GeV}$ at 95% confidence level for $\ensuremath{\chi}\ensuremath{\chi}\ensuremath{\rightarrow}b\overline{b}$ channel assuming $s$-wave annihilation a thermal cross section...
In the next decade, advances in our understanding of microbes and microbiomes will likely transform way life; providing novel therapeutics, alternate energy sources, shaping fundamental doctrines biology. We explore promises herein, tools required to achieve this progress. Notably, it is critical that we improve inclusivity diversity research agendas teams, so science benefits people all identities backgrounds.
The Wilkinson Microwave Anisotropy Probe (WMAP) experiment has detected reionization at the $5.5 \sigma$ level and reported a mean optical depth of $0.088 \pm 0.015$. A powerful probe is large-angle $EE$ polarization power spectrum, which now (since first five years data from WMAP) cosmic variance limited for $2\le l \le6$. Here we consider partial caused by WIMP dark matter annihilation, calculate expected spectrum. We compare models with standard 2-step theory, examine whether may be...
We study primordial magnetic field effects on the matter perturbations in Universe. assume generation prior to big bang nucleosynthesis (BBN), i.e. during radiation dominated epoch of Universe expansion, but do not limit analysis by considering a particular magnetogenesis scenario. Contrary previous studies, we total energy density and smoothed amplitude at large (order 1 Mpc) scales. review several cosmological signatures, such as halos abundance, thermal Sunyaev Zel'dovich (tSZ) effect,...