1,575 research outputs found
Production of DL-Methionine from Corn Syrup via Biosynthesis with Corynebacterium glutamicum
DL-methionine is an important feed additive for poultry and swine diets. The amino acid is not produced by animals so it can only be obtained through diet. Methionine is important for protein growth and helps the health of livestock. Recent increase in meat consumption in Latin America and Asia, along with a growing consumer concern of animal welfare, has driven a growth in the methionine market. The methionine market is predicted to continue to grow for at least another five years (Methionine Market 2019). The proposed design is for a process that produces DL-methionine by fermentation with the bacteria, Corynebacterium glutamicum. The plant has a capacity of 250 kilotonnes/year and will be located in Cedar Rapids, IA. According to a 20 year profitability analysis, it has an estimated IRR of 16.43% and in 2042 it has an NPV of 3.60/kg
Optimization Problem Formulation for Predicting Knee Muscle and Contact Forces during Gait
The human body has more muscles than degrees of freedom (DOF), which leads to indeterminacy in the muscle force calculation. In this study, an optimization problem to estimate the lower-limb muscle forces during a gait cycle of a patient wearing an instrumented knee prosthesis is formulated. It consists of simulating muscle excitations in a physiological way while muscle parameters are calibrated
Methodological considerations when translating "burnout"
No study has systematically examined how researchers address cross-cultural adaptation of burnout. We conducted an integrative review to examine how researchers had adapted the instruments to the different contexts. We reviewed the Content Validity Indexing scores for the Maslach Burnout Inventory-Human Services Survey from the 12-country comparative nursing workforce study, RN4CAST. In the integrative review, multiple issues related to translation were found in existing studies. In the cross-cultural instrument analysis, 7 out of 22 items on the instrument received an extremely low kappa score. Investigators may need to employ more rigorous cross-cultural adaptation methods when attempting to measure burnout
Formulation to Predict Lower Limb Muscle Forces during Gait
The human body has more muscles than Degrees of Freedom (DoF), and that leads to indeterminacy in the muscle force calculation. This study proposes the formulation of an optimization problem to estimate the lower-limb muscle forces during a gait cycle of a patient wearing an instrumented knee prosthesis. The originality of that formulation consists of simulating muscle excitations in a physiological way while muscle parameters are calibrated. Two approaches have been considered. In Approach A, measured contact forces are applied to the model and all inverse dynamics loads are matched in order to get a physiological calibration of muscle parameters. In Approach B, only the inverse dynamics loads not affected by the knee contact loads are matched. With that approach, contact forces can be predicted and validated by comparison with the experimental ones. Approach B is a test of the optimization method and it can be used for cases where no knee contact forces are available
Muscle Synergies Improve Estimation of Knee Contact Forces during Walking
This study investigates whether use of subject-specific muscle synergies can improve optimization predictions of muscle excitation patterns and knee contact forces during walking. Muscle synergies describe how a small number of neural commands generated by the nervous system can be linearly combined to produce the broad range of muscle electromyographic (EMG) signals measured experimentally. By quantifying the interdependence of individual EMG signals, muscle synergies provide dimensionality reduction for the neural control redundancy problem. Our hypothesis was that use of subjectspecific muscle synergies to limit muscle excitation patterns would improve prediction of muscle EMG patterns at the hip, knee, and ankle and of contact forces at the knee using a subject-specific lower body musculoskeletal computer model. The predictions were evaluated against in vivo experimental data collected from a subject implanted with a force-measuring tibial prosthesis
Synergies Controls Improve Prediction of Knee Contact Forces and Muscle Excitations during Gait
This study investigates whether use of muscle excitation controls constructed from subjectspecific muscle synergy information can improve optimization prediction of knee contact forces and muscle excitations during walking. Muscle synergies quantify how a large number of experimental muscle electromyographic (EMG) signals can be reconstructed by linearly mixing a much smaller number of neural commands generated by the nervous system. Our hypothesis was that controlling all muscle excitations with a small set of experimentally calculated neural commands would improve prediction of knee contact forces and leg muscle excitations compared to using independently controlled muscle excitations
On the mass segregation of stars and brown dwarfs in Taurus
We use the new minimum spanning tree (MST) method to look for mass
segregation in the Taurus association. The method computes the ratio of MST
lengths of any chosen subset of objects, including the most massive stars and
brown dwarfs, to the MST lengths of random sets of stars and brown dwarfs in
the cluster. This mass segregation ratio (Lambda_MSR) enables a quantitative
measure of the spatial distribution of high-mass and low-mass stars, and brown
dwarfs to be made in Taurus.
We find that the most massive stars in Taurus are inversely mass segregated,
with Lambda_MSR = 0.70 +/- 0.10 (Lambda_MSR = 1 corresponds to no mass
segregation), which differs from the strong mass segregation signatures found
in more dense and massive clusters such as Orion. The brown dwarfs in Taurus
are not mass segregated, although we find evidence that some low-mass stars
are, with an Lambda_MSR = 1.25 +/- 0.15. Finally, we compare our results to
previous measures of the spatial distribution of stars and brown dwarfs in
Taurus, and briefly discuss their implications.Comment: 10 pages, 8 figures, accepted for publication in MNRA
Disrupting the Repeat Domain of Premelanosome Protein (PMEL) Produces Dysamyloidosis and Dystrophic Ocular Pigment Reflective of Pigmentary Glaucoma
Pigmentary glaucoma has recently been associated with missense mutations in PMEL that are dominantly inherited and enriched in the proteinâs fascinating repeat domain. PMEL pathobiology is intriguing because PMEL forms functional amyloid in healthy eyes, and this PMEL amyloid acts to scaffold melanin deposition. This is an informative contradistinction to prominent neurodegenerative diseases where amyloid formation is neurotoxic and mutations cause a toxic gain of function called âamyloidosisâ. Preclinical animal models have failed to model this PMEL âdysamyloidosisâ pathomechanism and instead cause recessively inherited ocular pigment defects via PMEL loss of function; they have not addressed the consequences of disrupting PMELâs repetitive region. Here, we use CRISPR to engineer a small in-frame mutation in the zebrafish homolog of PMEL that is predicted to subtly disrupt the proteinâs repetitive region. Homozygous mutant larvae displayed pigmentation phenotypes and altered eye morphogenesis similar to presumptive null larvae. Heterozygous mutants had disrupted eye morphogenesis and disrupted pigment deposition in their retinal melanosomes. The deficits in the pigment deposition of these young adult fish were not accompanied by any detectable glaucomatous changes in intraocular pressure or retinal morphology. Overall, the data provide important in vivo validation that subtle PMEL mutations can cause a dominantly inherited pigment pathology that aligns with the inheritance of pigmentary glaucoma patient pedigrees. These in vivo observations help to resolve controversy regarding the necessity of PMELâs repeat domain in pigmentation. The data foster an ongoing interest in an antithetical dysamyloidosis mechanism that, akin to the amyloidosis of devastating dementias, manifests as a slow progressive neurodegenerative disease
Neutral-Current Atmospheric Neutrino Flux Measurement Using Neutrino-Proton Elastic Scattering in Super-Kamiokande
Recent results show that atmospheric oscillate with eV and , and that
conversion into is strongly disfavored. The Super-Kamiokande (SK)
collaboration, using a combination of three techniques, reports that their data
favor over . This distinction
is extremely important for both four-neutrino models and cosmology. We propose
that neutrino-proton elastic scattering () in water
\v{C}erenkov detectors can also distinguish between active and sterile
oscillations. This was not previously recognized as a useful channel since only
about 2% of struck protons are above the \v{C}erenkov threshold. Nevertheless,
in the present SK data there should be about 40 identifiable events. We show
that these events have unique particle identification characteristics, point in
the direction of the incoming neutrinos, and correspond to a narrow range of
neutrino energies (1-3 GeV, oscillating near the horizon). This channel will be
particularly important in Hyper-Kamiokande, with times higher rate.
Our results have other important applications. First, for a similarly small
fraction of atmospheric neutrino quasielastic events, the proton is
relativistic. This uniquely selects (not ) events,
useful for understanding matter effects, and allows determination of the
neutrino energy and direction, useful for the dependence of oscillations.
Second, using accelerator neutrinos, both elastic and quasielastic events with
relativistic protons can be seen in the K2K 1-kton near detector and MiniBooNE.Comment: 10 pages RevTeX, 8 figure
Is Incarceration a Contributor to Health Disparities? Access to Care of Formerly Incarcerated Adults
Despite the disproportionate prevalence of incarceration in communities of color, few studies have examined its contribution to health disparities. We examined whether a lifetime history of incarceration is associated with recent access to medical and dental care. We performed a secondary data analysis of the 2007 Los Angeles County Health Survey, a population-based random-digit-dialing telephone survey of county households. Any history of incarceration in a prison/jail/detention center as an adult was assessed for a random subsample. Bivariate and multivariate logistic regression analyses examined whether incarceration history was associated with access to care, controlling for other characteristics. Ten percent of our study population reported a history of incarceration. While persons with an incarceration history were similar to their peers with regard to health and insurance status, their access to medical and dental care was worse. Incarceration history was independently associated with disparities in access to care. Interventions to improve the health of communities affected by high rates of incarceration could include efforts that enable access to care for formerly incarcerated adults
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