271 research outputs found
Ytterbium-doped tantalum pentoxide waveguide lasers
We have demonstrated a Yb:Ta2O5 waveguide laser fabricated by RF magnetron sputtering on oxidised silicon. The waveguide laser was end-pumped with a laser diode at 977 nm and lasing was observed between 1015 and 1020 nm. The launched pump power threshold and slope efficiency were measured to be ~25 mW and 1.78 %, respectively
Development, Operation, and Results From the Texas Automated Buoy System
The Texas Automated Buoy System (TABS) is a coastal network of moored buoys that report near-real-time observations about currents and winds along the Texas coast. Established in 1995, the primary mission of TABS is ocean observations in the service of oil spill preparedness and response. The state of Texas funded the system with the intent of improving the data available to oil spill trajectory modelers. In its 12 years of operation, TABS has proven its usefulness during realistic oil spill drills and actual spills. The original capabilities of TABS, i.e., measurement of surface currents and temperatures, have been extended to the marine surface layer, the entire water column, and the sea floor. In addition to observations, a modeling component has been integrated into the TABS program. The goal is to form the core of a complete ocean observing system for Texas waters. As the nation embarks on the development of an integrated ocean observing system, TABS will continue to be an active participant of the Gulf of Mexico Coastal Ocean Observing System (GCOOS) regional association and the primary source of near-surface current measurements in the northwestern Gulf of Mexico. This article describes the origin of TABS, the philosophy behind the operation and development of the system, the resulting modifications to improve the system, the expansion of the system to include new sensors, the development of TABS forecasting models and real-time analysis tools, and how TABS has met many of the societal goals envisioned for GCOOS
Editorial: Accelerating Genetic Gains in Pulses
Legumes, members of the Fabaceae/Leguminosae family, are the third largest family of higher
plants with almost 20,000 species belonging to 650 genera, and are ubiquitous all over the
world. Among all legumes, pulse crops or food legumes fall into the four clades of the
subfamily Papilionoideae which include aeschynomenoids/dalbergiods, genistoids, hologalegina,
and phaseoloids/millettoids. They are distinctive due to their positive impact on agricultural and
environmental sustainability and have a prominent role in promoting human and animal health,
soil amelioration, cropping system diversification, and sustenance of rural livelihoods (Pratap et al.,
2021a). These also provide protein isolates that are increasingly being used in the food industry
as functional ingredients suitable for vegan diets (Robinson et al., 2019). The inclusion of pulses
in rotation with cereals helps to improve system yields, enhance net carbon sequestration, and
lower the carbon footprint. Nonetheless, in addition to being an excellent source of protein, starch,
and micronutrients, pulses also contain anti-nutritional compounds that can interfere with the
absorption of minerals (Moore et al., 2018) and also the digestion of protein (Clemente et al., 2015).
Realizing their importance, significant research has been dedicated to their genetic amelioration,
thereby turning them into mainstream crops from so-called âorphan legumesâ. Classical plant
breeding methods led to the development of more than 3,800 improved varieties of different pulse
crops globally, with improved attributes of grain yield, crop duration, stress resistance, nutrition
quality, etc. However, despite this effort, the increase in average pulse yields (from 637 to 1,009
kg/ha) has been modest compared to dramatic increases in cereal productivity (from 1,353 to
4,074 kg/ha) between 1961 and 2017 (Kumar et al., 2020). Among legumes, Koester et al. (2014)
studied 80 years of historical data of soybean breeding at the Crop Research and Education Center
in Urbana, USA and reported a genetic gain of 26.5 kg haâ1
yearâ1
, attributing the gain in grain
yield to increases in light interception, energy conversion, and partitioning efficiencies. Productivity
gains in pulses have been recorded when especially considered along with the markedly reduced
duration of the improved varieties, leading to increased cropping intensity, while genetic gains
have been recorded for traits imparting resistance to major biotic and abiotic stresses, herbicide
tolerance, larger seeds, and improved nutritional quality. This resulted in the growth, in terms of
production and productivity, in major pulse-producing countries. For example, India witnessed
the highest growth in production in mung bean (178%), followed by chickpea (125%), urdbean
(90%), pigeonpea (51%), and lentil (34%) in the last 15 years (Gaur, 2021). Notably, breeding in
most pulses has remained confined to the exploitation of genetic variation within the primary gene
pool, which has resulted in a narrow genetic base in most of them
Basal and inducible anti-inflammatory epoxygenase activity in endothelial cells
The roles of CYP lipid-metabolizing pathways in endothelial cells are poorly understood. Human endothelial cells expressed CYP2J2 and soluble epoxide hydrolase (sEH) mRNA and protein. The TLR-4 agonist LPS (1 ÎŒg/ml; 24 h) induced CYP2J2 but not sEH mRNA and protein. LCâMS/MS analysis of the stable commonly used human endothelial cell line EA.Hy926 showed active epoxygenase and epoxide hydrolase activity: with arachidonic acid (stable epoxide products 5,6-DHET, and 14,15-DHET), linoleic acid (9,10-EPOME and 12,13-EPOME and their stable epoxide hydrolase products 9,10-DHOME and 12,13-DHOME), docosahexaenoic acid (stable epoxide hydrolase product 19,20-DiHDPA) and eicosapentaenoic acid (stable epoxide hydrolase product 17,18-DHET) being formed. Inhibition of epoxygenases using either SKF525A or MS-PPOH induced TNFα release, but did not affect LPS, IL-1ÎČ, or phorbol-12-myristate-13-acetate (PMA)-induced TNFα release. In contrast, inhibition of soluble epoxide hydrolase by AUDA or TPPU inhibited basal, LPS, IL-1ÎČ and PMA induced TNFα release, and LPS-induced NFÎșB p65 nuclear translocation. In conclusion, human endothelial cells contain a TLR-4 regulated epoxygenase CYP2J2 and metabolize linoleic acid > eicosapentaenoic acid > arachidonic acid > docosahexaenoic acid to products with anti-inflammatory activity
Discrete- and Continuous-Time Probabilistic Models and Algorithms for Inferring Neuronal UP and DOWN States
UP and DOWN states, the periodic fluctuations between increased and decreased spiking activity of a neuronal population, are a fundamental feature of cortical circuits. Understanding UP-DOWN state dynamics is important for understanding how these circuits represent and transmit information in the brain. To date, limited work has been done on characterizing the stochastic properties of UP-DOWN state dynamics. We present a set of Markov and semi-Markov discrete- and continuous-time probability models for estimating UP and DOWN states from multiunit neural spiking activity. We model multiunit neural spiking activity as a stochastic point process, modulated by the hidden (UP and DOWN) states and the ensemble spiking history. We estimate jointly the hidden states and the model parameters by maximum likelihood using an expectation-maximization (EM) algorithm and a Monte Carlo EM algorithm that uses reversible-jump Markov chain Monte Carlo sampling in the E-step. We apply our models and algorithms in the analysis of both simulated multiunit spiking activity and actual multi- unit spiking activity recorded from primary somatosensory cortex in a behaving rat during slow-wave sleep. Our approach provides a statistical characterization of UP-DOWN state dynamics that can serve as a basis for verifying and refining mechanistic descriptions of this process.National Institutes of Health (U.S.) (Grant R01-DA015644)National Institutes of Health (U.S.) (Director Pioneer Award DP1- OD003646)National Institutes of Health (U.S.) (NIH/NHLBI grant R01-HL084502)National Institutes of Health (U.S.) (NIH institutional NRSA grant T32 HL07901
Empirical transmit field bias correction of T1w/T2w myelin maps
T1-weighted divided by T2-weighted (T1w/T2w) myelin maps were initially developed for neuroanatomical analyses such as identifying cortical areas, but they are increasingly used in statistical comparisons across individuals and groups with other variables of interest. Existing T1w/T2w myelin maps contain radiofrequency transmit field (B1+) biases, which may be correlated with these variables of interest, leading to potentially spurious results. Here we propose two empirical methods for correcting these transmit field biases using either explicit measures of the transmit field or alternatively a \u27pseudo-transmit\u27 approach that is highly correlated with the transmit field at 3T. We find that the resulting corrected T1w/T2w myelin maps are both better neuroanatomical measures (e.g., for use in cross-species comparisons), and more appropriate for statistical comparisons of relative T1w/T2w differences across individuals and groups (e.g., sex, age, or body-mass-index) within a consistently acquired study at 3T. We recommend that investigators who use the T1w/T2w approach for mapping cortical myelin use these B1+ transmit field corrected myelin maps going forward
"Beads on a String" Star Formation Tied to one of the most Powerful AGN Outbursts Observed in a Cool Core Galaxy Cluster
With two central galaxies engaged in a major merger and a remarkable chain of
19 young stellar superclusters wound around them in projection, the galaxy
cluster SDSS J1531+3414 () offers an excellent laboratory to study the
interplay between mergers, AGN feedback, and star formation. New Chandra X-ray
imaging reveals rapidly cooling hot ( K) intracluster gas, with two
"wings" forming a concave density discontinuity near the edge of the cool core.
LOFAR MHz observations uncover diffuse radio emission strikingly aligned
with the "wings," suggesting that the "wings" are actually the opening to a
giant X-ray supercavity. The steep radio emission is likely an ancient relic of
one of the most energetic AGN outbursts observed, with erg. To
the north of the supercavity, GMOS detects warm ( K) ionized gas
that enshrouds the stellar superclusters but is redshifted up to km
s with respect to the southern central galaxy. ALMA detects a similarly
redshifted M reservoir of cold ( K)
molecular gas, but it is offset from the young stars by kpc. We
propose that the multiphase gas originated from low-entropy gas entrained by
the X-ray supercavity, attribute the offset between the young stars and the
molecular gas to turbulent intracluster gas motions, and suggest that tidal
interactions stimulated the "beads on a string" star formation morphology.Comment: Accepted by ApJ, 36 pages, 23 figure
Returning Individual Research Results from Digital Phenotyping in Psychiatry
Psychiatry is rapidly adopting digital phenotyping and artificial intelligence/machine learning tools to study mental illness based on tracking participantsâ locations, online activity, phone and text message usage, heart rate, sleep, physical activity, and more. Existing ethical frameworks for return of individual research results (IRRs) are inadequate to guide researchers for when, if, and how to return this unprecedented number of potentially sensitive results about each participantâs real-world behavior. To address this gap, we convened an interdisciplinary expert working group, supported by a National Institute of Mental Health grant. Building on established guidelines and the emerging norm of returning results in participant-centered research, we present a novel framework specific to the ethical, legal, and social implications of returning IRRs in digital phenotyping research. Our framework offers researchers, clinicians, and Institutional Review Boards (IRBs) urgently needed guidance, and the principles developed here in the context of psychiatry will be readily adaptable to other therapeutic areas
Analysis of Protein Palmitoylation Reveals a Pervasive Role in Plasmodium Development and Pathogenesis
Asexual stage Plasmodium falciparum replicates
and undergoes a tightly regulated developmental
process in human erythrocytes. One mechanism
involved in the regulation of this process is posttranslational
modification (PTM) of parasite proteins.
Palmitoylation is a PTM in which cysteine residues
undergo a reversible lipid modification, which can
regulate target proteins in diverse ways. Using complementary
palmitoyl protein purification approaches
and quantitative mass spectrometry, we
examined protein palmitoylation in asexual-stage
P. falciparum parasites and identified over 400 palmitoylated
proteins, including those involved in cytoadherence,
drug resistance, signaling, development,
and invasion. Consistent with the prevalence of
palmitoylated proteins, palmitoylation is essential
for P. falciparum asexual development and influences
erythrocyte invasion by directly regulating
the stability of components of the actin-myosin invasion
motor. Furthermore, P. falciparum uses palmitoylation
in diverse ways, stably modifying some
proteins while dynamically palmitoylating others.
Palmitoylation therefore plays a central role in regulating
P. falciparum blood stage development
- âŠ