4,800 research outputs found
The LIL for -statistics in Hilbert spaces
We give necessary and sufficient conditions for the (bounded) law of the
iterated logarithm for -statistics in Hilbert spaces. As a tool we also
develop moment and tail estimates for canonical Hilbert-space valued
-statistics of arbitrary order, which are of independent interest
Zinc Sulphate Turbidity as a Screening Test of Passive Transfer of Immunity in Newborn Foals
Background: Passive immunity acquired by colostrum ingestion is essential to prevent neonatal infections. Failure of passive transfer (FPT) of maternal immunity occurs in foals that fail to absorb enough immunoglobulins within 24 h after birth. Foals with FPT are at increased risk of infections and death. Serum samples from neonatal foals might be examined for FPT using the zinc sulphate turbidity (ZST) test. The aim of this study was to investigate the accuracy of the ZST test, performed at two different times after first suckling (12 and 18 h), to detect FPT in newborn foals. The effect of temperature on the turbidity intensity resulting from the ZST reaction was also investigated.Materials, Methods & Results: Blood samples were collected from 112 newborn foals at 12 h after the first colostrum intake. In 36 foals, additional serum samples were collected at 18 h after first colostrum intake. The serum samples were tested with the ZST test and, later, in the laboratory setting, the ZST test was repeated. The IgG levels were measured by single radial immunodiffusion (SRID), which was used as the reference method. The standard solution used for the interpretation of results had a turbidity corresponding to approximately 800 mg/dL of immunoglobulins (IgG). The mean IgG concentration measured at 12 and 18 h after the first colostrum intake was analyzed using the t-test for paired samples. Values of absorbance of ZST test under different temperatures were analyzed using a one-way analysis of variance, and means were compared using the Tukey test. The relationship between the temperature of the solution and absorbance was determined using the Pearson’s correlation coefficient. Based on SRID results, 12 foals (10.7%) had serum IgG concentration 0.05) between 12 h (943.9 ± 508.6 mg/dL) and 18 h (975.9 ± 525.6 mg/dL) after the first colostrum intake. The sensitivity values were 76.3% and 71.0% (P > 0.05) for tests performed at farm and laboratory, respectively. The specificity was higher (P < 0.05) for ZST tests performed at laboratory (94.6%) than at farms (73.0%). Twenty-nine of the 38 foals (76.3%) with IgG < 800 mg/dL were correctly detected using the ZST test at farms. There was a strong correlation (r = 0.92; P < 0.0001) between the temperature of the solution test and the degree of turbidity. The absorbance after the reaction of serum with zinc sulphate was similar between the temperatures of 30, 34 and 37ºC, which had higher values than 20 and 25ºC.Discussion: The ZST test can be performed at 12 h after the first suckling. The lower specificity of tests run at farms compared to laboratory resulted in more foals with false positive diagnosis. The main cause of false positives at farms was probably the low temperature of the zinc sulphate solution at the time of testing, delaying the reaction and underestimating the IgG concentration. This assumption was reinforced by the increased specificity observed when the test was repeated with the same serum samples under controlled temperature of a laboratory. Additionally, the positive correlation observed between the temperature and degree of turbidity confirms that the reaction is temperature dependent. In the Southern hemisphere, most Thoroughbred foals are born during winter, when room temperature is far below the ideal temperature for good performance of the ZST test. Therefore, the number of false positives will likely be reduced if tests are performed at the farms under adequate temperature of solution (between 30 and 37ºC). This will reduce the number of foals receiving unnecessary treatment
Hubble Space Telescope WFC3 Grism Spectroscopy and Imaging of a Growing Compact Galaxy at z=1.9
We present HST/WFC3 grism spectroscopy of the brightest galaxy at z>1.5 in
the GOODS-South WFC3 Early Release Science grism pointing, covering the
wavelength range 0.9-1.7 micron. The spectrum is of remarkable quality and
shows the redshifted Balmer lines Hbeta, Hgamma, and Hdelta in absorption at
z=1.902, correcting previous erroneous redshift measurements from the
rest-frame UV. The average rest-frame equivalent width of the Balmer lines is
8+-1 Angstrom, which can be produced by a post-starburst stellar population
with a luminosity-weighted age of ~0.5 Gyr. The M/L ratio inferred from the
spectrum implies a stellar mass of ~4x10^11 Msun. We determine the morphology
of the galaxy from a deep WFC3 F160W image. Similar to other massive galaxies
at z~2 the galaxy is compact, with an effective radius of 2.1+-0.3 kpc.
Although most of the light is in a compact core, the galaxy has two red, smooth
spiral arms that appear to be tidally-induced. The spatially-resolved
spectroscopy demonstrates that the center of the galaxy is quiescent and the
surrounding disk is forming stars, as it shows Hbeta in emission. The galaxy is
interacting with a companion at a projected distance of 18 kpc, which also
shows prominent tidal features. The companion has a slightly redder spectrum
than the primary galaxy but is a factor of ~10 fainter and may have a lower
metallicity. It is tempting to interpret these observations as "smoking gun"
evidence for the growth of compact, quiescent high redshift galaxies through
minor mergers, which has been proposed by several recent observational and
theoretical studies. Interestingly both objects host luminous AGNs, as
indicated by their X-ray luminosities, which implies that these mergers can be
accompanied by significant black hole growth. This study illustrates the power
of moderate dispersion, low background near-IR spectroscopy at HST resolution,
which is now available with the WFC3 grism.Comment: 5 pages, 5 figures. Submitted to ApJ Letters
Constraints on dark energy models from radial baryon acoustic scale measurements
We use the radial baryon acoustic oscillation (BAO) measurements of Gaztanaga
et al. (2008) to constrain parameters of dark energy models. These constraints
are comparable with constraints from other "non-radial" BAO data. The radial
BAO data are consistent with the time-independent cosmological constant model
but do not rule out time-varying dark energy. When we combine radial BAO and
the Kowalski et al. (2008) Union type Ia supernova data we get very tight
constraints on dark energy.Comment: 24 pages, 8 figures, 1 table. Minor changes to match the published
versio
Specific lid-base contacts in the 26s proteasome control the conformational switching required for substrate degradation.
The 26S proteasome is essential for proteostasis and the regulation of vital processes through ATP-dependent degradation of ubiquitinated substrates. To accomplish the multi-step degradation process, the proteasomes regulatory particle, consisting of lid and base subcomplexes, undergoes major conformational changes whose origin is unknown. Investigating the Saccharomyces cerevisiae proteasome, we found that peripheral interactions between the lid subunit Rpn5 and the base AAA+ ATPase ring are important for stabilizing the substrate-engagement-competent state and coordinating the conformational switch to processing states upon substrate engagement. Disrupting these interactions perturbs the conformational equilibrium and interferes with degradation initiation, while later processing steps remain unaffected. Similar defects in early degradation steps are observed when eliminating hydrolysis in the ATPase subunit Rpt6, whose nucleotide state seems to control proteasome conformational transitions. These results provide important insight into interaction networks that coordinate conformational changes with various stages of degradation, and how modulators of conformational equilibria may influence substrate turnover
Ages and Metallicities of Hickson Compact Group Galaxies
Hickson Compact Groups (HCGs) constitute an interesting extreme in the range
of environments in which galaxies are located, as the space density of galaxies
in these small groups are otherwise only found in the centres of much larger
clusters. The work presented here uses Lick indices to make a comparison of
ages and chemical compositions of galaxies in HCGs with those in other
environments (clusters, loose groups and the field). The metallicity and
relative abundance of `-elements' show strong correlations with galaxy
age and central velocity dispersion, with similar trends found in all
environments. However, we show that the previously reported correlation between
-element abundance ratios and velocity dispersion disappears when a
full account is taken of the the abundance ratio pattern in the calibration
stars. This correlation is thus found to be an artifact of incomplete
calibration to the Lick system.
Variations are seen in the ranges and average values of age, metallicity and
-element abundance ratios for galaxies in different environments. Age
distributions support the hierarchical formation prediction that field galaxies
are on average younger than their cluster counterparts. However, the ages of
HCG galaxies are shown to be more similar to those of cluster galaxies than
those in the field, contrary to the expectations of current hierarchical
models. A trend for lower velocity dispersion galaxies to be younger was also
seen. This is again inconsistent with hierarchical collapse models, but is
qualitatively consistent with the latest N-body-SPH models based on monolithic
collapse in which star formation continues for many Gyr in low mass halos.Comment: 18 pages. Submitted for publication in MNRA
Determining Quasar Black Hole Mass Functions from their Broad Emission Lines: Application to the Bright Quasar Survey
We describe a Bayesian approach to estimating quasar black hole mass
functions (BHMF) when using the broad emission lines to estimate black hole
mass. We show how using the broad line mass estimates in combination with
statistical techniques developed for luminosity function estimation leads to
statistically biased results. We derive the likelihood function for the BHMF
based on the broad line mass estimates, and derive the posterior distribution
for the BHMF, given the observed data. We develop our statistical approach for
a flexible model where the BHMF is modelled as a mixture of Gaussian functions.
Statistical inference is performed using markov chain monte carlo (MCMC)
methods. Our method has the advantage that it is able to constrain the BHMF
even beyond the survey detection limits at the adopted confidence level,
accounts for measurement errors and the intrinsic uncertainty in broad line
mass estimates, and provides a natural way of estimating the probability
distribution of any quantities derived from the BHMF. We conclude by using our
method to estimate the local active BHMF using the z < 0.5 Bright Quasar Survey
sources. At z = 0.2, the quasar BHMF falls off approximately as a power law
with slope ~ 2 for M_{BH} > 10^8. Our analysis implies that z < 0.5 broad line
quasars have a typical Eddington ratio of ~ 0.4 and a dispersion in Eddington
ratio of < 0.5 dex (abridged).Comment: 25 pages, 14 figures, emulate ApJ style, accepted by Ap
Efficacy and safety of enzyme replacement therapy with BMN 110 (elosulfase alfa) for Morquio A syndrome (mucopolysaccharidosis IVA): a phase 3 randomised placebo-controlled study.
ObjectiveTo assess the efficacy and safety of enzyme replacement therapy (ERT) with BMN 110 (elosulfase alfa) in patients with Morquio A syndrome (mucopolysaccharidosis IVA).MethodsPatients with Morquio A aged ≥5 years (N = 176) were randomised (1:1:1) to receive elosulfase alfa 2.0 mg/kg/every other week (qow), elosulfase alfa 2.0 mg/kg/week (weekly) or placebo for 24 weeks in this phase 3, double-blind, randomised study. The primary efficacy measure was 6-min walk test (6MWT) distance. Secondary efficacy measures were 3-min stair climb test (3MSCT) followed by change in urine keratan sulfate (KS). Various exploratory measures included respiratory function tests. Patient safety was also evaluated.ResultsAt week 24, the estimated mean effect on the 6MWT versus placebo was 22.5 m (95 % CI 4.0, 40.9; P = 0.017) for weekly and 0.5 m (95 % CI -17.8, 18.9; P = 0.954) for qow. The estimated mean effect on 3MSCT was 1.1 stairs/min (95 % CI -2.1, 4.4; P = 0.494) for weekly and -0.5 stairs/min (95 % CI -3.7, 2.8; P = 0.778) for qow. Normalised urine KS was reduced at 24 weeks in both regimens. In the weekly dose group, 22.4 % of patients had adverse events leading to an infusion interruption/discontinuation requiring medical intervention (only 1.3 % of all infusions in this group) over 6 months. No adverse events led to permanent treatment discontinuation.ConclusionsElosulfase alfa improved endurance as measured by the 6MWT in the weekly but not qow dose group, did not improve endurance on the 3MSCT, reduced urine KS, and had an acceptable safety profile
PATTERNS OF FOREST LOSS PER TERRITORIAL CATEGORY IN THE AMAZON RAINFOREST: PERU (2001–2016)
The objective of the present study was to analyze the patterns of forest loss in the Peruvian Amazon between 2001 and 2016 according to 16 territorial categories and two types of land tenure (public and private) and administration (public and private). Through descriptive analysis and multivariate analysis using official forest loss data provided by the Peruvian government, a progressive increase in forest loss was detected over time, with the highest peaks in 2009, 2014, and 2016. The departments of San Martín, Loreto, and Ucayali presented the greatest loss. The three territorial categories with the greatest forest loss were the noncategorized areas (NCs), indigenous communities with land titles (ICTs), and rural lands (RLs). The NC category did not affect the general tendency of deforestation in Peru given that the forest loss dynamics in this category were similar to those of other territorial categories with assigned land rights
Indução da ovulação com gonadotrofina coriônica humana em éguas Crioulas
The effect of age, follicular diameter and month of the breeding season (September to January) on the hCG induction of ovulation was evaluated using 123 Criollo mares. Age varied between two and 24 years and the animals were examined daily by rectal palpation and ultrasonography with a 5 MHz linear transducer. When ovarian follicles reached a diameter of 30 to 35 mm, ovulation was induced with an i.v. injection of 1000 IU (n = 39); 1500 IU (n = 41) or 2000 IU (n = 43) of hCG. The mares were bred the next day and examined daily until ovulation was detected. The percentage of mares ovulating before 24 h of hCG injection was 10.3%, 7.3% and 4.7%; until 48 h after injection 92.3%, 85.3% and 86.0% of the mares treated with 1000, 1500 and 2000 IU of hCG, respectively, ovulated. The month of the breeding season, age of the mares and follicular diameter had no influence on ovulatory response. The three hCG doses used in Criollo mares (P >; 0.05) result in the induction of ovulation within 48 h after injection when a pre-ovulatory follicle with a 30 to 35 mm diameter was identified. A single dose of 1000 IU of hCG is efficient to induce ovulation in Criollo mares.O efeito da idade, diâmetro folicular e mês da estação de monta (setembro a janeiro) na indução da ovulação com hCG foi avaliado em 123 éguas Crioulas. A idade das éguas variou entre dois e 24 anos e os animais foram examinados diariamente por palpação retal e ultrassonografia com transdutor linear de 5 MHz. Quando os folículos ovarianos atingiram diâmetro de 30 a 35 milímetros aplicou-se uma injeção intravenosa com 1000 UI (n = 39); 1500 UI (n = 41) ou 2000 UI (n = 43) de hCG. As éguas foram cobertas no dia seguinte e examinadas diariamente até a detecção da ovulação. O percentual de éguas que ovularam antes de 24 h da injeção de hCG foi de 10,3%, 7,3% e 4,7%, até 48h após a injeção foi de 92,3%, 85,3% e 86,0%, nos grupos com 1000, 1500 e 2000 UI de hCG, respectivamente. O mês da estação de monta, a idade das éguas ou o diâmetro folicular não influenciaram a resposta ovulatória. As três doses de hCG utilizadas em éguas Crioulas (P >; 0,05) resultaram na indução da ovulação dentro de 48h após a aplicação, quando foi identificado um folículo pré-ovulatório de 30 a 35 mm de diâmetro. Uma única dose de 1000 UI de hCG é eficiente para induzir a ovulação em éguas Crioulas
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