Results 1 - 10 of 1818
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[en] This paper first evaluates the relative importance of the soil-plant-animal and soil-animal pathways of Zn, Cu and (especially) Pb investigated over a 15-month study period at 12 floodplain sites located within and downstream of the mineralised and historic mining area of mid-Wales, and secondly considers the implications of a sequential extraction procedure (SEP) undertaken on soils of varying particle size sampled from the study locations. Generally, very good agreement was found between the chemical partitioning of the three metals for each of the physical soil fractions subjected to the SEP. The availability of Pb to pasture vegetation, especially at the contaminated sites, is indicated with its associations with the more soluble (i.e. exchangeable and Fe/Mn oxide) soil phases, yet soil and/or plant barriers effectively restrict above-ground herbage concentrations of this metal. Consequently, with sheep ingesting soil at rates varying according to season from 0.1% to 44% or more of dry matter intake, the soil-animal pathway accounts for the majority of Pb consumption through most of the year, and at moderately and highly contaminated sites significant quantities of relatively soluble soil-Pb can be ingested at rates exceeding safety threshold limits.
[en] In the late 1990s, the epidemic in Jilin province in China started to come back and lead to re-rising of the number of the infected human. Consequently, government is adopting standard control measures: vaccination, detection-culling and tracking-culling of sheep and so on. Due to limited government funding, which measure is the most economical is need to further investigate. In this paper, based on the transmission mechanism of brucellosis between sheep and human, we establish a dynamical model to assess these three measures. Besides the analysis of dynamical behavior of model, the economic factors are considered to estimate costs of control measures. By numerical simulation, we obtain that at present, the cost of vaccination of sheep population in Jilin province is the largest, and the tracking-culling is the smallest. For detection-culling, the theoretical cost during 20 years is largest when the detection rate is 0.4. All these provide theoretical basis and guidance for brucellosis control.
[en] Ethiopia, which was designed to determine the rumen microbial composition of black head Ogaden sheep in comparison with highland sheep. The areas experience shorter rainy seasons (October/November and March/April) and the prolonged dry season. During the rainy season animals have access to fresh grass and water but during the dry periods animals hardly get grass pasture as the severe weather dries out the grass and what remains in the grazing field is a highly fibrous and lignified material. During the dry periods animals are usually compelled to survive on the scarcely available thorny trees and shrubs among which Acacias and Cactus are the most prominent. A total of 44 rumen fluid samples were collected both in dry and rainy seasons and kept at -80 deg C until processed and finally DNA was extracted. Also rumen samples were collected from five highland sheep (from sheep of the institute) for comparison. The randomly selected four samples (two collected in dry season, one collected in rainy season and one highland sheep samples) were tested with real time PCR against total bacteria, protozoa, anaerobic fungi, F. succinogenes, R. flavefaciens and methanogens. The study indicated that the population of methanogenes of black head Ogaden sheep showed that 12.6 to 23.58 fold lower and also R. flavifaciens 6.4 to 10.12 fold lower than highland sheep. The population of rumen microbes of Black head Ogaden sheep samples collected during rainy season were generally much lower than highland sheep (61.3 to 95.8% less), while anaerobi fungi of Blackhead Ogaden sheep samples collected during dry season was exceptionally 117 to 311 % higher than highland sheep. Generally this study indicated that Blackhead Ogaden sheep has low rumen microbial population including methanogens
[en] Objectives: To introduce a new transseptal (TS) needle assembled in our laboratory—the coaxial TS (CTS) needle—and describe our experience with it in creating experimental atrial septal defects (ASD) in adult sheep.BackgroundWith commercially available TS needles, we were not able to consistently perform TS puncture at the fossa ovalis in adult sheep.Material and MethodsTen adult sheep with a mean weight of 63.5 kg were used. The CTS needle consists of four components: a 9F Teflon catheter, a 14-gauge blunt curved-tip metal cannula, a 4F tapered catheter, and a 20-gauge open needle. A transjugular 5F pigtail catheter was used to display the septal anatomy by angiocardiography and was left in place to mark the level of the fossa ovalis. The septum was then probed by a transfemoral 5F curved-tip end-hole catheter. The CTS needle was aligned with the tip of the transjugular catheter, and the TS puncture was performed under fluoroscopic guidance. After documenting a left atrial position, a balloon angioplasty catheter was used for creation of the ASD. Results: A small patent foramen ovale was discovered by septal probing in one sheep. All sheep underwent successful TS punctures without complications. The ASD size ranged from 13 to 15 mm. In eight sheep, the ASD was in fossa ovalis. In the first two sheep where the needle was not well aligned with the marking catheter, the ASD was in the septum secundum. No damage to the atrial or other heart structures was found at necropsy. Conclusion: The CTS needle is a suitable needle for TS puncture and ASD creation in adult sheep. Proper alignment of the CTS needle with a catheter marking the fossa ovalis is essential for successful puncture.
[en] Protein Phosphatase 2A (PP2A) is a major serine/threonine phosphatase in cells. It consists of a catalytic subunit (C), a structural subunit (A), and a regulatory/variable B-type subunit. PP2A has a critical role to play in homeostasis where its predominant function is as a phosphatase that regulates the major cell signaling pathways in cells. Changes in the assembly, activity and substrate specificity of the PP2A holoenzyme have a direct role in disease and are a major contributor to the maintenance of the transformed phenotype in cancer. We have learned a lot about how PP2A functions from specific mutations that disrupt the core assembly of PP2A and from viral proteins that target PP2A and inhibit its effect as a phosphatase. This prompted various studies revealing that restoration of PP2A activity benefits some cancer patients. However, our understanding of the mechanism of action of this is limited because of the complex nature of PP2A holoenzyme assembly and because it acts through a wide variety of signaling pathways. Information on PP2A is also conflicting as there are situations whereby inactivation of PP2A induces apoptosis in many cancer cells. In this review we discuss this relationship and we also address many of the pertinent and topical questions that relate to novel therapeutic strategies aimed at altering PP2A activity
[en] The purpose of this study was to compare, after embolization, the distribution in the uterine arterial vasculature of tris-acryl gelatin microspheres (TGMS) and polyvinyl alcohol microspheres (PVAMS). A limited bilateral uterine artery embolization was performed in six adult sheep under fluoroscopic control by injecting in each uterine artery 0.25 ml of 500- to 700-μm TGMS of PVAMS suspended in 50/50 saline/contrast medium. Sacrifices were performed 1 week after embolization and uteri were analyzed histologically. The number and size of microspheres and vessels were measured, as well as the histological location according to a classification in four zones of the uterus. One hundred sixty-five vessels (69 vessels occluded with TGMS and 96 vessels occluded with PVAMS) were measured. The size of the occluded vessels decreased significantly from proximal to distal zones of the uterine vasculature (P < 0.0001). The location of TGMS and PVAMS within the vasculature was significantly different (P < 0.0001) since PVAMS blocked significantly more distally than TGMS. Deformation of the microspheres within the tissue was greater for PVAMS (18.0% ± 12.3%) than for TGMS (8.7% ± 9.2%) (P < 0.0001). In conclusion, PVAMS have a more distal distribution in the sheep uterine vasculature, compared to TGMS. Such differences in partition, already described in the kidney embolization model, can ultimately explain the different clinical outcome reported with these two types of microspheres in uterine fibroid embolization.
[en] Data collected from 3190 small ruminants (2408 ewe and 782 goats) have been examined after slaughtering, from January to June 2005 in Ouagadougou refrigerated abattoir. 26.70% of sheep and 34.91% of goats were more in advanced gravidity with losses estimated to 0.33 lamb and 0.44 kid per slaughtered sheep and goat. Animals slaughtered during the second half of their gravidity (2-5 months) represented 53.19% of sheep and 58.24% of goats although at this period, the foetus becomes palpable and detectable. This survey attracts the attention on the losses due to the slaughtering of pregnant females, as the deficit in animal proteins doesn't stop worsening. Urgent measures must be considered to decrease the extent of these losses and it is recommended to detect pregnancy females in abattoir and breeders must be trained to simple methods of gestation detection
[en] An on-farm in Kenya to evaluate the merits of a strategic drenching regime against the existing control measures showed that it was difficult to get statistically significant sample sizes within individual farms and that differences in farm management existed especially where animals are communally grazed. Consequently, production data were rendered difficult to analyse and interpret. Unlike in on-station trials, it was evident that the large number of smallholder farms (up to 80) that was required for realistic statistical comparisons conflicted with the limits of logistics and funding. The strategic treatment for gastrointestinal nematodes in sheep resulted in lower mean faecal egg counts in treated animals for most of the study period but overall, there was no significant effect of strategic treatment over the existing treatments on FEC, birth weight and growth rates in lambs. Possible approaches in future studies, could include use of clusters of smallholder farms that are far apart in different treatment groups. Commonly grazed flocks can either be excluded completely in such trials or if that method of grazing is predominant, entire village or cleary designated locations could be used in different treatment groups. Even with above, the use of production data (growth rate, off-take, mortality etc) need to be handled with great caution
[en] A Merino breeding resource flock was established at Rafter 7 Ranch, Yerington, Nevada through cooperation of the College of Agriculture, Biotechnology and Natural Resources, University of Nevada-Reno (UNR) and The Edwin L Wiegand Trust in 1990. Initially, 500 Rambouillet ewes were purchased from two established breeders in 1990. These ewes were bred naturally or by AI to imported rams from Australia and to rams selected within the flock. Over the 16 years, 16 rams and semen from 41 rams have been imported from Australia. Selection was based on objective wool measurements, subjective assessment, growth rate and reproductive performance traits. The flocks were expanded to 1300 ewes and were bred in 30 single sire-mating groups as of the 2005/2006 breeding seasons. Flock management is in two breeding lines, one as a registered Rafter 7 Pure Merino flock (n = 650) and the other (Merino x Rambouillet) as Rafter 7 Merino Line (n = 650), which are selected for high fleece weight and quality, twinning and growth traits. The spring lambing flock winters on desert rangelands, is grazed on irrigated pasture from shearing through lambing and early weaning. Merino crossbred ewes showed that wool fibre density, clean wool yield, staple length, and grease fleece weight were increased by 41% per unit area of skin, 15%, 2.5 cm and 1.14 kg per head shorn, respectively. The wool clip is classed on pre-shearing mid-side wool sample tests (OFDA 2000 system). Fleece weight and fibre diameter and staple length measurements are significantly improved over the years. Wool sales from the Rafter 7 Ranch have increased for volume, value and quality over years. Rafter 7 Ranch wool clip has topped seventh consecutive annual shearing for the highest price of US grown wool. Sheep producers from 18 states, and Mexico and Canada have purchased breeding rams and ewes annually from Rafter 7 ranch over the past 12 years. Objective and subjective measurement qualities are significantly improved in sale rams. Over 1000 breeding rams and 500 replacement ewes were distributed to range flocks in the western states in the last decade, which made a notable improvement for fleece weight, fibre diameter and yield in client's flocks. The dissemination of introduced Merino genetics in the western range sheep flocks will improve wool quality and clip profits, which strengthen a long-term competitive advantage for the US wool and sheep production sectors. (author)