275 research outputs found
Characteristics of fresh and frozen-thawed Uda ram semen extended with Oviplus®, egg yolk and coconut milk
Semen characteristics of Uda sheep and the effects of the egg yolk and coconut milkbased extenders on the quality of semen preserved at 4 oC and -196 oC were evaluated. Semen was collected from six Uda rams using an electro-ejaculator twice a week for ten weeks. Fresh semen samples were pooled and analyzed macroscopically and microscopically. The pooled semen was divided into 2 aliquots. One aliquot was extended in OviPlus® and egg yolk. The second aliquot was extended with OviPlus® and coconut milk. Each of the aliquots was further subdivided into 2 parts and evaluated microscopically. One part was chilled at 4 oC and evaluated for the same parameters after extension at 24, 48 and 72 hours. Second part was loaded into 0.25 ml plastic straws for cryopreservation at -196 ℃ and analyzed after 24 hours. The post thaw spermatozoa motility, livability and morphological abnormalities were determined at 24, 48 and 72 hours. The motility and concentration of freshly collected Uda semen were 81.7 ± 1.7 % and 3.2 ± 0.3 ×109/ml respectively. After extension, the motility decreased significantly (P < 0.05) from 82 % at 3 hours to 17 % at 72. The percentage live spermatozoa of the chilled semen did not differ significantly (P > 0.05) between the two extenders. Post thaw spermatozoa motility and livability were significantly (P < 0.05) reduced. There were significant differences (P < 0.05) between the post-thaw proportions of morphological abnormalities, between semen preserved at 4 oC and the frozen-thawed semen. In conclusion, semen motility, livability, and morphological abnormalities of Uda ram are equally preserved in coconut milk and egg yolk-based extenders at 4 oC up to 24 hours post extension. However, semen motility and livability were significantly reduced in the Uda semen earlier cryopreserved at -196 oC after thawing
A direct comparison of afferents to the rat anterior thalamic nuclei and nucleus reuniens: overlapping but different
Both nucleus reuniens and the anterior thalamic nuclei are densely interconnected with medial cortical and hippocampal areas, connections that reflect their respective contributions to learning and memory. To better appreciate their comparative roles, pairs of different retrograde tracers were placed in these two thalamic sites in adult rats. Both thalamic sites receive modest cortical inputs from layer V that contrasted with much denser projections from layer VI. Despite frequent overlap in layer VI, ventral prefrontal and anterior cingulate inputs to nucleus reuniens were concentrated in the deepest sublayer (VIb). Meanwhile, inputs to the anterior thalamic nuclei originated more evenly from both sublayers VIa and VIb, with the result that they were often located more superficially than the projections to nucleus reuniens. Again, while the many hippocampal (subiculum) neurons projecting to nucleus reuniens and the anterior thalamic nuclei were partially intermingled within the deep cellular parts of the subiculum, cells projecting to nucleus reuniens consistently tended to lie even deeper, i.e., immediately adjacent to the alveus. Variable numbers of double-labelled cells were present in those cortical and subicular portions where the two cell populations intermingled, though they remained in a minority. Our data also show how projections to these two thalamic sites are organized in opposing dorsal/ventral and rostral/caudal gradients across both the cortex and hippocampal formation. While the anterior thalamic nuclei are preferentially innervated by dorsal cortical sites, more ventral frontal sites preferentially reach nucleus reuniens. These anatomical differences may underpin the complementary cognitive functions of these two thalamic areas
A Raman Study of Morphotropic Phase Boundary in PbZr1-xTixO3 at low temperatures
Raman spectra of PbZr1-xTixO3 ceramics with titanium concentration varying
between 0.40 and 0.60 were measured at 7 K. By observing the
concentration-frequency dependence of vibrational modes, we identified the
boundaries among rhombohedral, monoclinic, and tetragonal ferroelectric phases.
The analysis of the spectra was made in the view of theory group analysis
making possible the assignment of some modes for the monoclinic phase.Comment: 5 pages, 4 figure
Detector Description and Performance for the First Coincidence Observations between LIGO and GEO
For 17 days in August and September 2002, the LIGO and GEO interferometer
gravitational wave detectors were operated in coincidence to produce their
first data for scientific analysis. Although the detectors were still far from
their design sensitivity levels, the data can be used to place better upper
limits on the flux of gravitational waves incident on the earth than previous
direct measurements. This paper describes the instruments and the data in some
detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial
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Predicting stroke through genetic risk functions: the CHARGE Risk Score Project.
BACKGROUND AND PURPOSE: Beyond the Framingham Stroke Risk Score, prediction of future stroke may improve with a genetic risk score (GRS) based on single-nucleotide polymorphisms associated with stroke and its risk factors.
METHODS: The study includes 4 population-based cohorts with 2047 first incident strokes from 22,720 initially stroke-free European origin participants aged ≥55 years, who were followed for up to 20 years. GRSs were constructed with 324 single-nucleotide polymorphisms implicated in stroke and 9 risk factors. The association of the GRS to first incident stroke was tested using Cox regression; the GRS predictive properties were assessed with area under the curve statistics comparing the GRS with age and sex, Framingham Stroke Risk Score models, and reclassification statistics. These analyses were performed per cohort and in a meta-analysis of pooled data. Replication was sought in a case-control study of ischemic stroke.
RESULTS: In the meta-analysis, adding the GRS to the Framingham Stroke Risk Score, age and sex model resulted in a significant improvement in discrimination (all stroke: Δjoint area under the curve=0.016, P=2.3×10(-6); ischemic stroke: Δjoint area under the curve=0.021, P=3.7×10(-7)), although the overall area under the curve remained low. In all the studies, there was a highly significantly improved net reclassification index (P<10(-4)).
CONCLUSIONS: The single-nucleotide polymorphisms associated with stroke and its risk factors result only in a small improvement in prediction of future stroke compared with the classical epidemiological risk factors for stroke
Weird exoskeletons: propositional politics and the making of home in underground Bucharest
The article explores the politics of life underground in Bucharest, Romania. It focuses on a tunnel passing under Bucharest's central train station, where a community of drug users and so‐called ‘homeless’ have made a long‐standing home, using a space that many others considered uninhabitable. Relying on extensive ethnographic observations and interviews undertaken within the tunnels, the article traces and illustrates the socio‐material entanglements characterizing life underground. It frames this assemblage of bodies, veins, syringes, substances and various relationships of power and affect, as a ‘propositional politics’ of home and life at the margins. Such a politics speaks of drug addiction and extreme marginalization, but also of a sense of belonging, reciprocal trust and care. In tracing such a politics, the article does not aim to romanticize the status of home in the underground or to treat it as the marginal antithesis of normative homeliness, but to reveal the ways in which an affirmative, self‐grounding politics of home emerges from the immanence of tunnel life within the fabric of the city. As such, the article contributes to debates around homing practices in conditions of uninhabitability and proposes a radical approach to the politics of life at the margins in the contemporary urban
Genome-wide meta-analyses reveal novel loci for verbal short-term memory and learning
Understanding the genomic basis of memory processes may help in combating neurodegenerative disorders. Hence, we examined the associations of common genetic variants with verbal short-term memory and verbal learning in adults without dementia or stroke (N = 53,637). We identified novel loci in the intronic region of CDH18, and at 13q21 and 3p21.1, as well as an expected signal in the APOE/APOC1/TOMM40 region. These results replicated in an independent sample. Functional and bioinformatic analyses supported many of these loci and further implicated POC1. We showed that polygenic score for verbal learning associated with brain activation in right parieto-occipital region during working memory task. Finally, we showed genetic correlations of these memory traits with several neurocognitive and health outcomes. Our findings suggest a role of several genomic loci in verbal memory processes
Optical and current transport properties of CuO/ZnO nanocoral p–n heterostructure hydrothermally synthesized at low temperature
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