1,426 research outputs found
High-resolution width-modulated pulse rebalance electronics for strapdown gyroscopes and accelerometers
Three different rebalance electronic loops were designed, implemented, and evaluated. The loops were width-modulated binary types using a 614.4 kHz keying signal; they were developed to accommodate the following three inertial sensors with the indicated resolution values: (1) Kearfott 2412 accelerometer - resolution = 260 micro-g/data pulse, (2) Honeywell GG334 gyroscope - resolution = 3.9 milli-arc-sec/data pulse, (3) Kearfott 2401-009 accelerometer - resolution = 144 milli-g/data pulse. Design theory, details of the design implementation, and experimental results for each loop are presented
Electronic Raman scattering in Magnetite, Spin vs. Charge gap
We report Raman scattering data of single crystals of magnetite (Fe3O4) with
Verwey transition temperatures (Tv) of 123 and 117K, respectively. Both single
crystals reveal broad electronic background extending up to 900 wavenumbers
(~110 meV). Redistribution of this background is observed when samples are
cooled below Tv. In particular, spectra of the low temperature phase show
diminished background below 300 wavenumbers followed by an enhancement of the
electronic background between 300 and 400 wavenumbers. To enhance the effect of
this background redistribution we divide the spectra just below the transition
by the spectra just above the transition. A resultant broad peak-like feature
is observed, centered at 370 wavenumbers (45 meV). The peak position of this
feature does not scale with the transition temperature. We discuss two
alternative assignments of this feature to a spin or charge gap in magnetite.Comment: 4 figures, 1 tabl
Metformin in gestational diabetes: the offspring follow-up (MiG TOFU): body composition and metabolic outcomes at 7-9 years of age
Objective: To compare body composition and metabolic outcomes at 7–9 years in offspring of women with gestational diabetes (GDM) randomized to metformin (±insulin) or insulin treatment during pregnancy. Research design and methods: Children were assessed at 7 years in Adelaide (n=109/181) and 9 years in Auckland (n=99/396) by anthropometry, bioimpedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI) (n=92/99) and fasting bloods (n=82/99). Results: In the Adelaide subgroup, mothers were similar at enrollment. Women randomized to metformin versus insulin had higher treatment glycemia (p=0.002) and more infants with birth weight >90th percentile (20.7% vs 5.9%; p=0.029). At 7 years, there were no differences in offspring measures. In Auckland, at enrollment, women randomized to metformin had a higher body mass index (BMI) (p=0.08) but gained less weight during treatment (p=0.07). Offspring birth measures were similar. At 9 years, metformin offspring were larger by measures of weight, arm and waist circumferences, waist:height (p<0.05); BMI, triceps skinfold (p=0.05); DXA fat mass and lean mass (p=0.07); MRI abdominal fat volume (p=0.051). Body fat percent was similar between treatment groups by DXA and BIA. Abdominal fat percentages (visceral adipose tissue, subcutaneous adipose tissue and liver) were similar by MRI. Fasting glucose, triglyceride, insulin, insulin resistance, glycosylated hemoglobin (HbA1c), cholesterol, liver transaminases, leptin and adiponectin were similar. Conclusions: Metformin or insulin for GDM was associated with similar offspring total and abdominal body fat percent and metabolic measures at 7–9 years. Metformin-exposed children were larger at 9 years. Metformin may interact with fetal environmental factors to influence offspring outcomes.Janet A Rowan, Elaine C Rush, Lindsay D Plank, Jun Lu, Victor Obolonkin, Suzette Coat, William M Hagu
ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs
This report, issued by the ACVIM Specialty of Cardiology consensus panel, revises guidelines for the diagnosis and treatment of myxomatous mitral valve disease (MMVD, also known as endocardiosis and degenerative or chronic valvular heart disease) in dogs, originally published in 2009. Updates were made to diagnostic, as well as medical, surgical, and dietary treatment recommendations. The strength of these recommendations was based on both the quantity and quality of available evidence supporting diagnostic and therapeutic decisions. Management of MMVD before the onset of clinical signs of heart failure has changed substantially compared with the 2009 guidelines, and new strategies to diagnose and treat advanced heart failure and pulmonary hypertension are reviewed
What voters want: reactions to candidate characteristics in a survey experiment
There has been extensive research into the extent to which voters utilise short cuts based on gender and race stereotypes when evaluating candidates, but relatively little is known about how they respond to other background characteristics. We compare the impact of candidates' sex, religion, age, education, occupation and location/residence through a survey experiment in which respondents rate two candidates based on short biographies. We find small differences in the ratings of candidates in response to sex, religion, age and education cues but more sizeable effects are apparent for the candidate's occupation and place of residence. Even once we introduce a control for political party into our experimental scenarios the effect of candidate's place of residence continues to have a sizeable impact on candidate evaluations. Our research suggests that students of electoral behaviour should pay attention to a wider range of candidate cues
Longitudinal Analysis of Quality of Life, Clinical, Radiographic, Echocardiographic, and Laboratory Variables in Dogs with Preclinical Myxomatous Mitral Valve Disease Receiving Pimobendan or Placebo: The EPIC Study
Background: Changes in clinical variables associated with the administration of pimobendan to dogs with preclinical myxomatous mitral valve disease (MMVD) and cardiomegaly have not been described.
Objectives: To investigate the effect of pimobendan on clinical variables and the relationship between a change in heart size and the time to congestive heart failure (CHF) or cardiac-related death (CRD) in dogs with MMVD and cardiomegaly. To determine whether pimobendan-treated dogs differ from dogs receiving placebo at onset of CHF.
Animals: Three hundred and fifty-four dogs with MMVD and cardiomegaly.
Materials and Methods: Prospective, blinded study with dogs randomized (ratio 1:1) to pimobendan (0.4-0.6 mg/kg/d) or placebo. Clinical, laboratory, and heart-size variables in both groups were measured and compared at different time points (day 35 and onset of CHF) and over the study duration. Relationships between short-term changes in echocardiographic variables and time to CHF or CRD were explored.
Results: At day 35, heart size had reduced in the pimobendan group:median change in (Delta) LVIDDN -0.06 (IQR:-0.15 to + 0.02), P < 0.0001, and LA:Ao -0.08 (IQR:-0.23 to + 0.03), P < 0.0001. Reduction in heart size was associated with increased time to CHF or CRD. Hazard ratio for a 0.1 increase in Delta LVIDDN was 1.26, P = 0.0003. Hazard ratio for a 0.1 increase in Delta LA:Ao was 1.14, P = 0.0002. At onset of CHF, groups were similar.
Conclusions and Clinical Importance: Pimobendan treatment reduces heart size. Reduced heart size is associated with improved outcome. At the onset of CHF, dogs treated with pimobendan were indistinguishable from those receiving placebo
Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study - A Randomized Clinical Trial
Background: Pimobendan is effective in treatment of dogs with congestive heart failure (CHF) secondary to myxomatous mitral valve disease (MMVD). Its effect on dogs before the onset of CHF is unknown. Hypothesis/Objectives: Administration of pimobendan (0.4-0.6 mg/kg/d in divided doses) to dogs with increased heart size secondary to preclinical MMVD, not receiving other cardiovascular medications, will delay the onset of signs of CHF, cardiac-related death, or euthanasia. Animals: 360 client-owned dogs with MMVD with left atrial-to-aortic ratio >= 1.6, normalized left ventricular internal diameter in diastole >= 1.7, and vertebral heart sum >10.5. Methods: Prospective, randomized, placebo-controlled, blinded, multicenter clinical trial. Primary outcome variable was time to a composite of the onset of CHF, cardiac-related death, or euthanasia. Results: Median time to primary endpoint was 1228 days (95% CI: 856-NA) in the pimobendan group and 766 days (95% CI: 667-875) in the placebo group (P = .0038). Hazard ratio for the pimobendan group was 0.64 (95% CI: 0.47-0.87) compared with the placebo group. The benefit persisted after adjustment for other variables. Adverse events were not different between treatment groups. Dogs in the pimobendan group lived longer (median survival time was 1059 days (95% CI: 952-NA) in the pimobendan group and 902 days (95% CI: 747-1061) in the placebo group) (P = .012). Conclusions and Clinical Importance: Administration of pimobendan to dogs with MMVD and echocardiographic and radiographic evidence of cardiomegaly results in prolongation of preclinical period and is safe and well tolerated. Prolongation of preclinical period by approximately 15 months represents substantial clinical benefit
Mid- and Far-infrared Luminosity Functions and Galaxy Evolution from Multiwavelength Spitzer Observations up to z~2.5
[Abridged]We exploit a large homogeneous dataset to derive a self-consistent
picture of IR emission based on the time-dependent 24, 15, 12 and 8micron
monochromatic and bolometric IR luminosity functions (LF) over the 0<z<2.5
redshift range. Our analysis is based on the combination of data from deep
Spitzer surveys in the VVDS-SWIRE and GOODS areas. To our limiting flux of
S(24)=400microJy our derived sample in VVDS-SWIRE includes 1494 sources, and
666 and 904 sources brighter than S(24)=80microJy are catalogued in GOODS-S and
GOODS-N, respectively, for a total area of ~0.9 square degs. We obtain reliable
optical identifications and redshifts, providing us a rich and robust dataset
for our luminosity function determination. Based on the multi-wavelength
information available, we constrain the LFs at 8, 12, 15 and 24micron. We also
extrapolate total IR luminosities from our best-fit to the observed SEDs of
each source, and use this to derive the bolometric LF and comoving volume
emissivity up to z~2.5. In the 0<z<1 interval, the bolometric IR luminosity
density evolves as (1+z)^3.8+/-0.4. Although more uncertain at higher-z, our
results show a flattening of the IR luminosity density at z>1. The mean
redshift of the peak in the source number density shifts with luminosity: the
brighest IR galaxies appear to be forming stars earlier in cosmic time (z>1.5),
while the less luminous ones keep doing it at more recent epochs (z~1 for
L(IR)<10^11L_sun). Our results suggest a rapid increase of the galaxy IR
comoving volume emissivity back to z~1 and a constant average emissivity at
z>1. We also seem to find a difference in the evolution rate of the source
number densities as a function of luminosity, a downsizing evolutionary pattern
similar to that reported from other samples of cosmic sources.Comment: Accepted for pubblicantion in Astronomy and Astrophysic
From glycosylation disorders to dolichol biosynthesis defects: a new class of metabolic diseases
Polyisoprenoid alcohols are membrane lipids that are present in every cell, conserved from archaea to higher eukaryotes. The most common form, alpha-saturated polyprenol or dolichol is present in all tissues and most organelle membranes of eukaryotic cells. Dolichol has a well defined role as a lipid carrier for the glycan precursor in the early stages of N-linked protein glycosylation, which is assembled in the endoplasmic reticulum of all eukaryotic cells. Other glycosylation processes including C- and O-mannosylation, GPI-anchor biosynthesis and O-glucosylation also depend on dolichol biosynthesis via the availability of dolichol-P-mannose and dolichol-P-glucose in the ER. The ubiquity of dolichol in cellular compartments that are not involved in glycosylation raises the possibility of additional functions independent of these protein post-translational modifications. The molecular basis of several steps involved in the synthesis and the recycling of dolichol and its derivatives is still unknown, which hampers further research into this direction. In this review, we summarize the current knowledge on structural and functional aspects of dolichol metabolites. We will describe the metabolic disorders with a defect in known steps of dolichol biosynthesis and recycling in human and discuss their pathogenic mechanisms. Exploration of the developmental, cellular and biochemical defects associated with these disorders will provide a better understanding of the functions of this lipid class in human
Obscured Activity: AGN, Quasars, Starbursts and ULIGs observed by the Infrared Space Observatory
Some of the most active galaxies in the Universe are obscured by large
quantities of dust and emit a substantial fraction of their bolometric
luminosity in the infrared. Observations of these infrared luminous galaxies
with the Infrared Space Observatory (ISO) have provided a relatively unabsorbed
view to the sources fuelling this active emission. The improved sensitivity,
spatial resolution and spectroscopic capability of ISO over its predecessor
Infrared Astronomical Satellite (IRAS), has enabled significant advances in the
understanding of the infrared properties of active galaxies. ISO surveyed a
wide range of active galaxies which, in the context of this review, includes
those powered by intense bursts of star-formation as well as those containing a
dominant active galactic nucleus (AGN). Mid infrared imaging resolved for the
first time the dust enshrouded nuclei in many nearby galaxies, while a new era
in infrared spectroscopy was opened by probing a wealth of atomic, ionic and
molecular lines as well as broad band features in the mid and far infrared.
This was particularly useful since it resulted in the understanding of the
power production, excitation and fuelling mechanisms in the nuclei of active
galaxies including the intriguing but so far elusive ultraluminous infrared
galaxies. Detailed studies of various classes of AGN and quasars greatly
improved our understanding of the unification scenario. Far-infrared imaging
and photometry also revealed the presence of a new very cold dust component in
galaxies and furthered our knowledge of the far-infrared properties of faint
starbursts, ULIGs and quasars. We summarise almost nine years of key results
based upon ISO data spanning the full range of luminosity and type of active
galaxies.Comment: Accepted for publication in 'ISO science legacy - a compact review of
ISO major achievements', Space Science Reviews - dedicated ISO issue. To be
published by Springer in 2005. 62 pages (low resolution figures version).
Higher resolution PDFs available from
http://users.physics.uoc.gr/~vassilis/papers/VermaA.pdf or
http://www.iso.vilspa.esa.es/science/SSR/Verma.pd
- …