4,485 research outputs found
Extraction of Recombinant Dog Gastric Lipase from Transgenic Corn Seed
Several approaches were examined for extracting the relatively hydrophobic protein recombinant dog gastric lipase (rDGL) expressed in the endosperm of transgenic corn seed. The first approach used minimal processing of the seed before extraction (i.e. simple grinding of whole seed) followed by selective extraction to eliminate 72% of contaminant proteins without compromising rDGL recovery from the meal of whole grain. The second approach added defatting of the whole grain meal to reduce the amount of detergent in the subsequent step for extracting rDGL. The third approach incorporated dry-milling of the corn to recover an endosperm rich fraction, followed by extraction of this fraction. The dry milling strategy was most effective, resulting in recovery of 35 U rDGL/g of corn seed (50 U/g of endosperm) with a specific activity of 9 U/mg compared to 22 U and 3 U/mg for the first strategy and 36 U and 3.7 U/mg for the second. The reductions in host protein contamination and lower detergent levels of the endosperm route should simplify downstream purification steps
Selection of important variables by statistical learning in genome-wide association analysis
Genetic analysis of complex diseases demands novel analytical methods to interpret data collected on thousands of variables by genome-wide association studies. The complexity of such analysis is multiplied when one has to consider interaction effects, be they among the genetic variations (G × G) or with environment risk factors (G × E). Several statistical learning methods seem quite promising in this context. Herein we consider applications of two such methods, random forest and Bayesian networks, to the simulated dataset for Genetic Analysis Workshop 16 Problem 3. Our evaluation study showed that an iterative search based on the random forest approach has the potential in selecting important variables, while Bayesian networks can capture some of the underlying causal relationships
Evaluating the use of blood pressure polygenic risk scores across race/ethnic background groups
We assess performance and limitations of polygenic risk scores (PRSs) for multiple blood pressure (BP) phenotypes in diverse population groups. We compare clumping-and-thresholding (PRSice2) and LD-based (LDPred2) methods to construct PRSs from each of multiple GWAS, as well as multi-PRS approaches that sum PRSs with and without weights, including PRS-CSx. We use datasets from the MGB Biobank, TOPMed study, UK biobank, and from All of Us to train, assess, and validate PRSs in groups defined by self-reported race/ethnic background (Asian, Black, Hispanic/Latino, and White). For both SBP and DBP, the PRS-CSx based PRS, constructed as a weighted sum of PRSs developed from multiple independent GWAS, perform best across all race/ethnic backgrounds. Stratified analysis in All of Us shows that PRSs are better predictive of BP in females compared to males, individuals without obesity, and middle-aged (40-60 years) compared to older and younger individuals
Physiochemical characteristic of Harvested Rain water from Bodo Community in Rivers State, Nigeria
This study was carried out to determine the quality of rainwater from three different roofing materials (asbestos, aluminum and zinc) in Bodo Community of Rivers State, Nigeria. Samples were taken to the laboratory and analyzed using standard analytical procedures. The average result obtained ranged from 6.0-7.0, 40-66 μsi/cm, 18-48 mg/l, 32.52-86.67 mg/L, 0.06-3.18 mg/L, 5.02-13.76 mg/L, 2.79-5.02 mg/L, 0.16-0.77 mg/L, 0.27-5.79 mg/L, 0.24 0.62 mg/L and 0.03-4.08 mg/L for pH, conductivity, chloride, salinity, nitrate, sulphate, sodium, magnesium, calcium, iron and zinc respectively. Of interest were rainwater samples from asbestos roofing sheets which gave high calcium and magnesium content. Also, zinc roofing sheet gave high zinc and iron content compared to other roofing sheets. Physico-chemical properties and metal content of the harvested water from the roofing sheets were considerably different from those of control samples (water collected directly from raindrop). This could mean that the impinging of rain drop on the roof gradually erodes the roof material or could be as a result of anthropogenic inputs (deposits of pollutants in contact with roofing sheet) or geographical location. Considering the result of the analysis the harvested water could be put to other domestic use, as they can not be consumed directly.Keywords: rainwater, roof materials, water qualit
High-Speed Fluorescence Imaging and Intensity Profiling of Femtosecond-Induced Calcium Transients
We have demonstrated a combined imaging system, where the
physiology of biological specimens can be imaged and profiled at 10–20 frames per second whilst undergoing femtosecond
laser irradiation. Individual GH3 cells labeled with the calcium
fluorophore Fluo-3 were stimulated using a counter-propagating
focused femtosecond beam with respect to the imaging system. As a
result of the stimulation, calcium waves can be generated in COS
cells, and laser-induced calcium oscillations are initiated in the
GH3 cells. Single-photon fluorescence images and intensity
profiles of the targeted specimens are sampled in real-time using
a modified PerkinElmer UltraView LCI microscope
Assistive VR Gym: Interactions with Real People to Improve Virtual Assistive Robots
Versatile robotic caregivers could benefit millions of people worldwide,
including older adults and people with disabilities. Recent work has explored
how robotic caregivers can learn to interact with people through physics
simulations, yet transferring what has been learned to real robots remains
challenging. Virtual reality (VR) has the potential to help bridge the gap
between simulations and the real world. We present Assistive VR Gym (AVR Gym),
which enables real people to interact with virtual assistive robots. We also
provide evidence that AVR Gym can help researchers improve the performance of
simulation-trained assistive robots with real people. Prior to AVR Gym, we
trained robot control policies (Original Policies) solely in simulation for
four robotic caregiving tasks (robot-assisted feeding, drinking, itch
scratching, and bed bathing) with two simulated robots (PR2 from Willow Garage
and Jaco from Kinova). With AVR Gym, we developed Revised Policies based on
insights gained from testing the Original policies with real people. Through a
formal study with eight participants in AVR Gym, we found that the Original
policies performed poorly, the Revised policies performed significantly better,
and that improvements to the biomechanical models used to train the Revised
policies resulted in simulated people that better match real participants.
Notably, participants significantly disagreed that the Original policies were
successful at assistance, but significantly agreed that the Revised policies
were successful at assistance. Overall, our results suggest that VR can be used
to improve the performance of simulation-trained control policies with real
people without putting people at risk, thereby serving as a valuable stepping
stone to real robotic assistance.Comment: IEEE International Conference on Robot and Human Interactive
Communication (RO-MAN 2020), 8 pages, 8 figures, 2 table
Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above The Paramagnetic Limit
We report the first magneto-caloric and calorimetric observations of a
magnetic-field-induced phase transition within a superconducting state to the
long-sought exotic "FFLO" superconducting state first predicted over 50 years
ago. Through the combination of bulk thermodynamic calorimetric and
magnetocaloric measurements in the organic superconductor -
(BEDT-TTF)Cu(NCS), as a function of temperature, magnetic field
strength, and magnetic field orientation, we establish for the first time that
this field-induced first-order phase transition at the paramagnetic limit
for traditional superconductivity is to a higher entropy superconducting phase
uniquely characteristic of the FFLO state. We also establish that this
high-field superconducting state displays the bulk paramagnetic ordering of
spin domains required of the FFLO state. These results rule out the alternate
possibility of spin-density wave (SDW) ordering in the high field
superconducting phase. The phase diagram determined from our measurements ---
including the observation of a phase transition into the FFLO phase at
--- is in good agreement with recent NMR results and our own earlier
tunnel-diode magnetic penetration depth experiments, but is in disagreement
with the only previous calorimetric report.Comment: 5 pages, 5 figure
Implicit Decomposition for Write-Efficient Connectivity Algorithms
The future of main memory appears to lie in the direction of new technologies
that provide strong capacity-to-performance ratios, but have write operations
that are much more expensive than reads in terms of latency, bandwidth, and
energy. Motivated by this trend, we propose sequential and parallel algorithms
to solve graph connectivity problems using significantly fewer writes than
conventional algorithms. Our primary algorithmic tool is the construction of an
-sized "implicit decomposition" of a bounded-degree graph on
nodes, which combined with read-only access to enables fast answers to
connectivity and biconnectivity queries on . The construction breaks the
linear-write "barrier", resulting in costs that are asymptotically lower than
conventional algorithms while adding only a modest cost to querying time. For
general non-sparse graphs on edges, we also provide the first writes
and operations parallel algorithms for connectivity and biconnectivity.
These algorithms provide insight into how applications can efficiently process
computations on large graphs in systems with read-write asymmetry
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