1,362 research outputs found
Not So Rare: Errors of Metabolism during the Neonatal Period
During the neonatal period, the diagnosis of an error of metabolism (EM) was once thought to portend a poor prognosis or lethality. Over the past two decades, the prognosis of many EMs has changed. The critical aspect of the metabolic evaluation in a sick newborn is to rapidly identify whether there may be a metabolic problem. If there is a metabolic problem, the goal is to minimize the sequelae of the specific disorder. This review will explore how to approach and evaluate a newborn suspected of having an EM. A discussion of clinical and laboratory findings that often accompany EM will be included
CHEMICALLY MODIFIED PHOTOSYNTHETIC BACTERIAL REACTION CENTERS: CIRCULAR DICHROISM, RAMAN RESONANCE, LOW TEMPERATURE ABSORPTION, FLUORESCENCE AND ODMR SPECTRA AND POLYPEPTIDE COMPOSITION OF BOROHYDRIDE TREATED REACTION CENTERS FROM Rhodobacter sphaeroides R26
Reaction centers from Rhodobacter sphaeroides have been modified by treatment with sodium borohydride similar to the original procedure [Ditson et al., Biochim. Biophys. Acta 766, 623 (1984)], and investigated spectroscopically and by gel electrophoresis.
(1) Low temperature (1.2 K) absorption, fluorescence, absorption- and fluorescence-detected ODMR, and microwave-induced singlet-triplet absorption difference spectra (MIA) suggest that the treatment produces a spectroscopically homogeneous preparation with one of the ‘additional’ bacteriochlorophylls being removed. The modification does not alter the zero field splitting parameters of the primary donor triplet (TP870).
(2) From the circular dichroism and Raman resonance spectra in the1500–1800 cm-1 region, the removed pigment is assigned to BchlM, e.g. the "extra" Bchl on the "inactive" M-branch.
(3) A strong coupling among all pigment molecules is deduced from the circular dichroism spectra, because pronounced band-shifts and/or intensity changes occur in the spectral components assigned to all pigments. This is supported by distinct differences among the MIA spectra of untreated and modified reaction centers, as well as by Raman resonance.
(4) The modification is accompanied by partial proteolytic cleavage of the M-subunit. The preparation is thus spectroscopically homogeneous, but biochemically heterogenous
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Evaluation of miglustat as maintenance therapy after enzyme therapy in adults with stable type 1 Gaucher disease: a prospective, open-label non-inferiority study.
BACKGROUND: Previous studies have provided equivocal data on the use of miglustat as maintenance therapy in Gaucher disease type 1. We report findings from a clinical trial evaluating the effects of miglustat treatment in patients with stable type 1 Gaucher disease after enzyme therapy. METHODS: Adult type 1 Gaucher disease patients stabilized during at least 3 years of previous enzyme therapy were included in this 2-year, prospective, open-label non-inferiority study. The primary endpoint was percent change from baseline in liver volume. Secondary endpoints included changes in spleen volume, hemoglobin concentration and platelet count. RESULTS: Forty-two patients were enrolled (mean±SD age, 45.1±12.7 years; previous enzyme therapy duration 9.5±4.0 years). Median (range) exposure to miglustat 100 mg t.i.d. was 658 (3-765) days. Twenty-one patients discontinued treatment prematurely; 13 due to adverse events, principally gastrointestinal. The upper 95% confidence limit of mean percent change in liver volume from baseline to end of treatment was below the non-inferiority margin of 10% (-1.1%; 95%CI -6.0, 3.9%). Mean (95%CI) changes in spleen volume, hemoglobin concentration and platelet count were 102 (24,180) mL, -0.95 (-1.38, -0.53) g/dL and -44.1 (-57.6, -30.7) ×109/L, respectively. CONCLUSIONS: The primary efficacy endpoint was met; overall there was no change in liver volume during 24 months of miglustat therapy. Several patients showed a gradual deterioration in some disease manifestations, suggesting that miglustat could maintain clinical stability, but not in all patients. Miglustat demonstrated a predictable profile of safety and tolerability that was consistent with that reported in previous clinical trials and experience in clinical practice. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT00319046.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Preserving entanglement under decoherence and sandwiching all separable states
Every entangled state can be perturbed, for instance by decoherence, and stay
entangled. For a large class of pure entangled states, we show how large the
perturbation can be. Our class includes all pure bipartite and all maximally
entangled states. For an entangled state, E, the constucted neighborhood of
entangled states is the region outside two parallel hyperplanes, which sandwich
the set of all separable states. The states for which these neighborhoods are
largest are the maximally entangled ones. As the number of particles, or the
dimensions of the Hilbert spaces for two of the particles increases, the
distance between two of the hyperplanes which sandwich the separable states
goes to zero. It is easy to decide if a state Q is in the neighborhood of
entangled states we construct for an entangled state E. One merely has to check
if the trace of EQ is greater than a constant which depends upon E and which we
determine.Comment: Corrected first author's e-mail address. All the rest remains
unchange
Elemental Abundances in the Ejecta of Old Classical Novae from Late-Epoch Spitzer Spectra
We present Spitzer Space Telescope mid-infrared IRS spectra, supplemented by
ground-based optical observations, of the classical novae V1974 Cyg, V382 Vel,
and V1494 Aql more than 11, 8, and 4 years after outburst respectively. The
spectra are dominated by forbidden emission from neon and oxygen, though in
some cases, there are weak signatures of magnesium, sulfur, and argon. We
investigate the geometry and distribution of the late time ejecta by
examination of the emission line profiles. Using nebular analysis in the low
density regime, we estimate lower limits on the abundances in these novae. In
V1974 Cyg and V382 Vel, our observations confirm the abundance estimates
presented by other authors and support the claims that these eruptions occurred
on ONe white dwarfs. We report the first detection of neon emission in V1494
Aql and show that the system most likely contains a CO white dwarf.Comment: 22 pages, 12 figure
Haldane-Gapped Spin Chains as Luttinger Liquids: Correlation Functions at Finite Field
We study the behavior of Heisenberg, antiferromagnetic, integer-spin chains
in the presence of a magnetic field exceeding the attendant spin gap. For
temperatures much smaller than the gap, the spin chains exhibit Luttinger
liquid behavior. We compute exactly both the corresponding Luttinger parameter
and the Fermi velocity as a function of magnetic field. This enables the
computation of a number of correlators from which we derive the spin
conductance, the expected form of the dynamic structure factor relevant to
inelastic neutron scattering experiments, and NMR relaxation rates. We also
comment upon the robustness of the magnetically induced gapless phase both to
finite temperature and finite couplings between neighbouring chains.Comment: 32 pages, 8 figures; published version includes additions discussing
the robustness of the magnetically induced gapless phase to ordering between
chains as well as the relationship between the spin-1 chains and spin-1/2
ladders in the presence of a magnetic fiel
Imputation Rules to Improve the Education Variable in the IAB Employment Subsample
The education variable in the IAB employment subsample has two shortcomings: missing values and inconsistencies with the reporting rule. We propose several deductive imputation procedures to improve the variable. They mainly use the multiple education information available in the data because the employees' education is reported at least once a year. We compare the improved data from the different procedures and the original data in typical applications in labor economics: educational composition of employment, wage inequality, and wage regression. We find, that correcting the education variable: (i) shows the educational attainment of the male labor force to be higher than measured with the original data, (ii) gives different values for some measures of wage inequality, and (iii) does not change the estimates in wage regressions much
Distrust And Dominance In Managing Alternative Work Arrangements: A Micro-Analytic Test Of Transaction Cost Theory
Organizations that successfully outsource may see better value-creation in creating a sustainable competitive advantage. The objectives of this study were threefold: a) provide a framework for studying the effects of perceived distrust that leads to dominance, b) analyze how opportunism parlays into the concept of dominance, and c) determine if the relationship between outsource partners varies by analyzing transaction characteristics. Our research shows that firms should take caution to fully understand the effects that contract size has on a firm’s resources. 
Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005
BACKGROUND. The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS. Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE. Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.NOAA Coral Reef Conservation Progra
Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005
BACKGROUND The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.This work was partially supported by salaries from the NOAA Coral Reef Conservation Program to the NOAA Coral Reef Conservation Program authors. NOAA provided funding to Caribbean ReefCheck investigators to undertake surveys of bleaching and mortality. Otherwise, no funding from outside authors' institutions was necessary for the undertaking of this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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