632 research outputs found
Efficacy in the field of two anticoccidial vaccines for broilers
We compared two attenuated anticoccidial vaccines, administered to broilers by spray into the incubator (88,000 males and 210,100 females). Vaccine A container five species of Eimeria and vaccine B three. Zootechnical performance was similar in the two groups, with mean lesion scores no higher than 1; vaccine A caused only duodenal lesions, while vaccine B also caused typhlitis. Maximum oocyst count was 23,000/g feces at age 28 days with vaccine A and 38,000 at 21 days with vaccine B. Broilers vaccinated with vaccine B had more frequent enteric symptoms, and C. perfringens isolation
Haemorrhagic enteritis seroconversion in turkey breeders: field observations
Seroconversion to viral haemorrhagic enteritis (HE) was studied in seven flocks of turkey breeders (17.974 birds in total), after 20 weeks of the onset of egg production. They showed no clinical signs, and mortality rate was normal. However, the infection caused a drop in egg production lasting about five weeks (-2.32 eggs laid during this period), but had no effect on hatching parameters
The 4 K outer cryostat for the CUORE experiment: construction and quality control
The external shell of the CUORE cryostat is a large cryogen-free system
designed to host the dilution refrigerator and the bolometers of the CUORE
experiment in a low radioactivity environment. The three vessels that form the
outer shell were produced and delivered to the Gran Sasso underground
Laboratories in July 2012. In this paper, we describe the production techniques
and the validation tests done at the production site in 2012.Comment: 11 pages, 13 figures; to appear in NIM
Characterization of Large Volume 3.5 x 8 inches LaBr3:Ce Detectors
The properties of large volume cylindrical 3.5 x 8 inches (89 mm x 203 mm)
LaBr3:Ce scintillation detectors coupled to the Hamamatsu R10233-100SEL
photo-multiplier tube were investigated. These crystals are among the largest
ones ever produced and still need to be fully characterized to determine how
these detectors can be utilized and in which applications. We tested the
detectors using monochromatic gamma-ray sources and in-beam reactions producing
gamma rays up to 22.6 MeV; we acquired PMT signal pulses and calculated
detector energy resolution and response linearity as a function of gamma-ray
energy. Two different voltage dividers were coupled to the Hamamatsu
R10233-100SEL PMT: the Hamamatsu E1198-26, based on straightforward resistive
network design, and the LABRVD, specifically designed for our large volume
LaBr3:Ce scintillation detectors, which also includes active semiconductor
devices. Because of the extremely high light yield of LaBr3:Ce crystals we
observed that, depending on the choice of PMT, voltage divider and applied
voltage, some significant deviation from the ideally proportional response of
the detector and some pulse shape deformation appear. In addition, crystal
non-homogeneities and PMT gain drifts affect the (measured) energy resolution
especially in case of high-energy gamma rays. We also measured the time
resolution of detectors with different sizes (from 1x1 inches up to 3.5x8
inches), correlating the results with both the intrinsic properties of PMTs and
GEANT simulations of the scintillation light collection process. The detector
absolute full energy efficiency was measured and simulated up to gamma-rays of
30 Me
Improving Sparse Representation-Based Classification Using Local Principal Component Analysis
Sparse representation-based classification (SRC), proposed by Wright et al.,
seeks the sparsest decomposition of a test sample over the dictionary of
training samples, with classification to the most-contributing class. Because
it assumes test samples can be written as linear combinations of their
same-class training samples, the success of SRC depends on the size and
representativeness of the training set. Our proposed classification algorithm
enlarges the training set by using local principal component analysis to
approximate the basis vectors of the tangent hyperplane of the class manifold
at each training sample. The dictionary in SRC is replaced by a local
dictionary that adapts to the test sample and includes training samples and
their corresponding tangent basis vectors. We use a synthetic data set and
three face databases to demonstrate that this method can achieve higher
classification accuracy than SRC in cases of sparse sampling, nonlinear class
manifolds, and stringent dimension reduction.Comment: Published in "Computational Intelligence for Pattern Recognition,"
editors Shyi-Ming Chen and Witold Pedrycz. The original publication is
available at http://www.springerlink.co
Estimating the intrinsic dimension of datasets by a minimal neighborhood information
Analyzing large volumes of high-dimensional data is an issue of fundamental importance in data science, molecular simulations and beyond. Several approaches work on the assumption that the important content of a dataset belongs to a manifold whose Intrinsic Dimension (ID) is much lower than the crude large number of coordinates. Such manifold is generally twisted and curved; in addition points on it will be non-uniformly distributed: two factors that make the identification of the ID and its exploitation really hard. Here we propose a new ID estimator using only the distance of the first and the second nearest neighbor of each point in the sample. This extreme minimality enables us to reduce the effects of curvature, of density variation, and the resulting computational cost. The ID estimator is theoretically exact in uniformly distributed datasets, and provides consistent measures in general. When used in combination with block analysis, it allows discriminating the relevant dimensions as a function of the block size. This allows estimating the ID even when the data lie on a manifold perturbed by a high-dimensional noise, a situation often encountered in real world data sets. We demonstrate the usefulness of the approach on molecular simulations and image analysis
The CUORE cryostat: an infrastructure for rare event searches at millikelvin temperatures
The CUORE experiment is the world's largest bolometric experiment. The
detector consists of an array of 988 TeO2 crystals, for a total mass of 742 kg.
CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso,
Italy, searching for the neutrinoless double beta decay of 130Te. A large
custom cryogen-free cryostat allows reaching and maintaining a base temperature
of about 10 mK, required for the optimal operation of the detector. This
apparatus has been designed in order to achieve a low noise environment, with
minimal contribution to the radioactive background for the experiment. In this
paper, we present an overview of the CUORE cryostat, together with a
description of all its sub-systems, focusing on the solutions identified to
satisfy the stringent requirements. We briefly illustrate the various phases of
the cryostat commissioning and highlight the relevant steps and milestones
achieved each time. Finally, we describe the successful cooldown of CUORE
Tuber donnagotto, a new winter truffle species from Istria, Croatia
Tuber donnagotto is a new winter black truffle belonging to the order
Pezizales and the family Tuberaceae. It grows in winter in the calcareous gravel soil (pH 7.6–7.8) near the Adriatic Sea (Rovinj, Istria, Croatia) in predominantly pine forests (Pinus halepensis). Although similar to other black truffles, it has very irregular and hard
fruit bodies, lobate and knotted in form, with deep irregular cavities reaching the middle of the fruit bodies. These cavities are clearly evident in the cross-section of the fruit bodies. A distinctive characteristic of this truffle is the fact that when it is hermetically closed it can be kept in a refrigerator (2–4 °C) for more than 60 days. Tuber donnagotto has a slight but pleasant odor, reminiscent of boletus (Boletus reticulates, B. edulis). Furthermore, T. donnagotto has yellow-brownish and reticulate-alveolate spores, measuring 20–30 × 20–25 mm
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