Abstract Bovine herpesvirus-1 (BoHV-1) causes significant disease in cattle. Control programs in North America incorporate vaccination with modified live viral (MLV) or killed (KV) vaccine. BoHV-1 ...strains are isolated from diseased animals or fetuses after vaccination. There are markers for differentiating MLV from field strains using whole-genome sequencing and analysis identifying single nucleotide polymorphisms (SNPs). Using multiple primer sets and sequencing of products permits association of BoHV-1 isolates with vaccines. To determine association between vaccine virus and strains isolated from clinical cases following vaccination, we analyzed 12 BoHV-1 isolates from animals with various clinical syndromes; 9 corresponded to BoHV-1.1 respiratory group. The remaining three corresponded to BoHV-1.2b, typically found in genital tracts of cattle. Four BoHV-1 isolates were identical to a vaccine strain; three were from post-vaccination abortion episodes with typical herpetic lesions whose dams had received MLV vaccine during pregnancy, and one from a heifer given a related MLV vaccine; Sequences of two respiratory isolates perfectly matched mutations characterizing RLB106 strain, a temperature sensitive mutant used in intranasal and parenteral vaccines. The last three respiratory strains clearly appeared related to a group of MLV vaccines. Previously the MLV vaccines were grouped into four groups based on SNPs patterns. In contrast with above-mentioned isolates that closely matched SNP patterns of their respective MLV vaccine virus, these 3 strains both lacked some and possessed a number of additional mutations compared to a group of MLV vaccine viral genome. Finding BoHV-1.2b in respiratory cases indicates focus should be given BoHV-1.2b as an emerging virus or a virus not recognized nor fully characterized in BRD.
Reward prediction errors (RPEs) and risk preferences have two things in common: both can shape decision making behavior, and both are commonly associated with dopamine. RPEs drive value learning and ...are thought to be represented in the phasic release of striatal dopamine. Risk preferences bias choices towards or away from uncertainty; they can be manipulated with drugs that target the dopaminergic system. Based on the common neural substrate, we hypothesize that RPEs and risk preferences are linked on the level of behavior as well. Here, we develop this hypothesis theoretically and test it empirically. First, we apply a recent theory of learning in the basal ganglia to predict how RPEs influence risk preferences. We find that positive RPEs should cause increased risk-seeking, while negative RPEs should cause risk-aversion. We then test our behavioral predictions using a novel bandit task in which value and risk vary independently across options. Critically, conditions are included where options vary in risk but are matched for value. We find that our prediction was correct: participants become more risk-seeking if choices are preceded by positive RPEs, and more risk-averse if choices are preceded by negative RPEs. These findings cannot be explained by other known effects, such as nonlinear utility curves or dynamic learning rates.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A 2-y-old female Grant’s zebra (Equus quagga burchellii boehmi) was presented with a clinical history of depression, anorexia, and weakness of 1-wk duration. Postmortem examination identified ulcers ...on the tongue and palate; a large abscess adjacent to the larynx; left lung consolidation; mild swelling, darkening, and congestion of the liver with accentuation of the lobular pattern; and edema and congestion of the distal small and large intestines. Histologic examination identified necrotizing bronchopneumonia, necrotizing hepatitis, nephritis, and enterocolitis. Eosinophilic intranuclear inclusions were detected in syncytial cells and degenerate bronchial epithelium in the lungs and in some hepatocytes associated with necrotic foci. Bacterial cultures of the lung, liver, and laryngeal abscess failed to detect any significant pathogen. Lung and liver tested positive for equine herpesvirus with neuropathogenic marker by real-time PCR. Subsequently, equine herpesvirus was isolated in tissue culture, and the entire viral DNA polymerase gene (ORF30) was sequenced. The zebra lung isolate had a very close nucleotide and amino acid sequence identity to equid alphaherpesvirus 9 (EHV-9; 99.6% and 99.8%, respectively) in contrast to the neuropathogenic T953 strain of EHV-1 (94.7% and 96.6%, respectively). Although zebras are considered the natural host for EHV-9, we document an unusual acute systemic, fatal EHV-9 infection in a 2-y-old Grant’s zebra.
Intense radiation from lasers has opened up many new areas of research in physics and chemistry, and has revolutionized optical technology. So far, most work in the field of nonlinear processes has ...been restricted to infrared, visible and ultraviolet light, although progress in the development of X-ray lasers has been made recently. With the advent of a free-electron laser in the soft-X-ray regime below 100 nm wavelength, a new light source is now available for experiments with intense, short-wavelength radiation that could be used to obtain deeper insights into the structure of matter. Other free-electron sources with even shorter wavelengths are planned for the future. Here we present initial results from a study of the interaction of soft X-ray radiation, generated by a free-electron laser, with Xe atoms and clusters. We find that, whereas Xe atoms become only singly ionized by the absorption of single photons, absorption in clusters is strongly enhanced. On average, each atom in large clusters absorbs up to 400 eV, corresponding to 30 photons. We suggest that the clusters are heated up and electrons are emitted after acquiring sufficient energy. The clusters finally disintegrate completely by Coulomb explosion.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Endocrine-disrupting chemicals have been known to alter important animal behaviors by modulating serotonin (5-hydroxytryptamine, 5-HT) and dopamine.
F. heteroclitus
(mummichog) brain serotonin and ...dopamine levels were quantified by enzyme-linked immunosorbent assay (ELISA) following a 28-day exposure regimen involving daily doses of either 0.1 mg l
−1
benzyl butyl phthalate (BBP) dissolved in acetone or acetone alone (0.1 mg l
−1
). No differences in mean brain mass or total protein homogenate were induced by exposure to the acetone vehicle or BBP in acetone. The acetone vehicle had no effect on dopamine, serotonin, or tyrosine hydroxylase levels, but acetone did decrease tryptophan hydroxylase levels (
p
= 0.011). Exposure to BBP in acetone decreased dopamine (
p
= 0.024), increased serotonin (
p
< 0.001), reduced tryptophan hydroxylase as compared to the acetone vehicle alone (
p
< 0.001), and had no significant effect on tyrosine hydroxylase levels. This study is the first to report modulation of
F. heteroclitus
brain serotonin and its enzyme tryptophan hydroxylase following sub-lethal exposure to BBP in an acetone vehicle. In addition, modulation of brain dopamine in
F. heteroclitus
, sans simultaneous modulation of tyrosine hydroxylase, was also observed. These findings support the use of
F. heteroclitus
for assessing sub-lethal BBP exposure.
The first quasi‐synoptic estimates of Arctic Ocean and sea ice net fluxes of volume, heat and freshwater are calculated by application of an inverse model to data around the ocean boundary. ...Hydrographic measurements from four gateways to the Arctic (Bering, Davis, and Fram Straits and the Barents Sea Opening) completely enclose the ocean, and were made within the same 32‐day period in summer 2005. The inverse model is formulated as a set of full‐depth and density‐layer‐specific volume and salinity transport conservation equations, with conservation constraints also applied to temperature, but only in non‐outcropping layers. The model includes representations of Fram Strait sea ice export and of interior Arctic Ocean diapycnal fluxes. The results show that in summer 2005 the transport‐weighted mean properties are, for water entering the Arctic: potential temperature 4.49°C, salinity 34.50 and potential density (σ0) 27.34 kg m−3; and for water leaving the Arctic, including sea ice: 0.25°C, 33.81, and 27.13 kg m−3, respectively. The net effect of the Arctic in summer is to freshen and cool the inflows by 0.69 in salinity and 4.23°C, respectively, and to decrease density by 0.21 kg m−3. The volume transport into the Arctic of waters above ∼1000 m depth is 9.2 Sv (1 Sv = 106 m3 s−1), and the export (similarly) is 9.3 Sv. The net oceanic and sea ice freshwater flux is 187 ± 48 mSv. The net heat flux (including sea ice) is 189 ± 37 TW, representing loss from the ocean to the atmosphere.
Key Points
A synoptic summer pan‐Arctic heat and freshwater boundary fluxes
California Animal Health and Food Safety Laboratory System, University of California, Tulare 93274, USA.
In an 8-year period, 1991-1998, 217 accessions of caprine abortions were submitted to the ...California Veterinary Diagnostic Laboratory System. Of these 217 submissions, 211 were suitable for examination in this study (6 had insufficient data). Infectious agents as the cause of abortions were found in 37% of the cases: bacterial agents were identified in 30.5%, viral agents in 2%, fungal agents in 0.5%, and protozoal agents in 4% of the cases submitted. The most common causes of abortions were Chlamydia psittaci and Coxiella burnetii infection, which accounted for 23% of all goat abortions. Mineral deficiencies were observed in 4%, fetal anomalies accounted for 3%, and leukoencephalomalacia of the brain (probable oxygen deprivation) accounted for 3% of the submissions. No diagnosis was made in 112 of the 211 submissions (53%). No lesions were noted in 104 of the submissions (49%). The other 8 submissions (4%) had histologic lesions suggestive of a bacterial agent; however, no infectious agents were identified in these cases.
Femtosecond x-ray laser flashes with power densities of up to 10(14) W/cm(2) at 13.7 nm wavelength were scattered by single xenon clusters in the gas phase. Similar to light scattering from ...atmospheric microparticles, the x-ray diffraction patterns carry information about the optical constants of the objects. However, the high flux of the x-ray laser induces severe transient changes of the electronic configuration, resulting in a tenfold increase of absorption in the developing nanoplasma. The modification in opaqueness can be correlated to strong atomic charging of the particle leading to excitation of Xe(4+). It is shown that single-shot single-particle scattering on femtosecond time scales yields insight into ultrafast processes in highly excited systems where conventional spectroscopy techniques are inherently blind.
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