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11.
This study was conducted to identify and analyse the expression of gametogenesis‐associated genes and proteins in foetal and adult buffalo gonads of both the sexes. Relative quantification of the genes was determined by qPCR and Western blotting. Immunohistochemistry was also performed for various gametogenesis‐associated proteins in foetal and adult gonads of both the sexes. We observed significantly (p < 0.05) increased expression of primordial germ cell‐specific, meiotic as well as genes associated with oocyte maturation and development in foetal ovaries as compared to the adult ones. However, significantly (p < 0.05) increased expression of proteins associated with oocyte maturation like GDF9 and ZP4 was found in adult ovaries, indicating temporal regulation of mRNA translation during oogenesis. Meiotic genes showed significantly (p < 0.05) increased expression in adult testes as compared to foetal testes and ovaries, indicating onset of meiosis at a later stage in spermatogenesis. In general, the expression of primordial germ cell‐associated as well as meiotic genes was higher in adult testes, indicating the increased biological activity in the organ. Immunohistochemistry revealed localized expression of gametogenesis‐associated proteins in ovarian follicles and seminiferous tubules of testes, while the surrounding somatic tissues were devoid of these proteins. The study gives an understanding of the sequential and temporal events of gene expression as well as mRNA translation during male and female gametogenesis. It could also be concluded that follicles and seminiferous tubules are the functional units of the female and male gonads, respectively, and their function could be enhanced by appropriate chemical and genetic intervention of the somatic tissue immediately surrounding them. This assumes importance in the context that buffalo attains sexual maturity at an older age of 2–3 years and have smaller ovaries with lesser number of primordial follicles in comparison with cattle, which is suggested to be the main reason of their poor breeding performance.  相似文献   
12.
A kuroko-type polymetallic sulfide deposit in a submarine silicic caldera   总被引:1,自引:0,他引:1  
Manned submersible studies have delineated a large and actively growing Kuroko-type volcanogenic massive sulfide deposit 400 kilometers south of Tokyo in Myojin Knoll submarine caldera. The sulfide body is located on the caldera floor at a depth of 1210 to 1360 meters, has an area of 400 by 400 by 30 meters, and is notably rich in gold and silver. The discovery of a large Kuroko-type polymetallic sulfide deposit in this arc-front caldera raises the possibility that the numerous unexplored submarine silicic calderas elsewhere might have similar deposits.  相似文献   
13.
A number of insecticides used for ectoparasite control in the livestock industry were screened for their efficacy against larvae of the screw-worm fly, Chrysomya bezziana, using in vivo and laboratory tests. Proprietary screw-worm fly treatments (after exposure to outdoor conditions for up to 10 days) were also tested against eggs and adults of C bezziana. Three of these were also evaluated on naturally acquired screw-worm infestations. Residual protection was generally of short duration. Among the organophosphorus compounds, the most effective formulations contained relatively high concentrations (3 to 4% al) of coumaphos, 2.5% fenchlorphos or low concentrations (0.05 to 0.5% al) of diazinon, chlorfenvinphos and fenthion methyl. Two chlorinated hydrocarbon insecticides containing 3% lindane and 5% dieldrin were very effective but are now prohibited for use in Australia. Preparations had serious deficiencies when used under field conditions, especially for treating large, deepseated myiases for which systemic insecticides are recommended. A comparison of methods demonstrated that a laboratory test could supersede live animal experimentation, at least for the initial screening of potential insecticides.  相似文献   
14.
Abstract

AIMS: The aims of this cross-sectional study were to investigate the herd and cow-level prevalence of bovine digital dermatitis (BDD) in dairy farms in the northern Taranaki region of New Zealand, and to identify whether there was any spatial clustering of herds with the disease.

METHODS: A survey of 224 dairy farms in the northern Taranaki region of New Zealand was undertaken from September 2014 to February 2015. Following training in robust criteria to confirm BDD visually, a technician inspected the rear feet of every milking cow on the farms during milking. The identity of cows with lesions and the feet involved were recorded. The proportion of cows affected among the inspected population (cow-level prevalence), the proportion of a herd affected (farm-level prevalence), and proportion of farms with ≥1 cow with lesions, were calculated. A bivariate K function analysis was then used to assess whether farms with ≥1 cow with lesions were clustered, after accounting for the distribution of the farms involved in the study.

RESULTS: Bovine digital dermatitis lesions were observed on 143/224 (63.8 (95% CI=57.5–70.1)%) farms. Within-farm prevalence was 0% on 81 (36.2%) farms, between >0 and <3% on 120 (53.5%) farms, with a maximum prevalence of 12.7% on one farm. Overall, cow-level prevalence was 707/60,455 (1.2 (95% CI=0.9–3.0)%), and on affected farms was 707/41,116 (1.7 (95% CI=1.4–2.1)%). In affected cows, 268/707 (37.9%) had a lesion on left foot only, 262/707 (37.1%) on the right foot only and 177/707 (25.0%) on both feet. The K function analysis showed no evidence of clustering of farms with BDD.

CONCLUSIONS: Bovine digital dermatitis was widespread among the survey farms, but there was no evidence that there was any clustering of herds with BDD. The cow-level prevalence on affected farms was much lower than reported elsewhere.

CLINICAL RELEVANCE: Although the prevalence at the cow level was low, if these data are representative of other regions of New Zealand, BDD could easily become a major problem on dairy farms in New Zealand, as has been observed in other countries.  相似文献   
15.
A long-term field experiment was initiated in November, 1967 at Research Area of Department of Soil Science to study the response of nitrogen to pearl millet-wheat cropping system at various doses and modes of farmyard manure application. The soil organic carbon increased with farmyard manure application and ranged from 0.68% in control to 1.82% in the plot receiving the highest annual dose (90 Mg ha?1) of farmyard manure. To study the contribution of farmyard manure on the productivity of pearl millet and wheat crops, the constants (intercept and slope) were determined between the grain yield of pearl millet and wheat crops with increasing dose of fertilizer nitrogen. Another linear regression was fitted between the intercept of the linear model and the soil organic carbon content. It has been observed that with each unit increase in the soil organic carbon, the productivity of pearl millet increased by 273 kg ha?1 and that of wheat by 1591 kg ha?1. The regression between the slope and soil organic carbon was linear in case of pearl millet (R2 0.49) but in case of wheat there was no relationship.  相似文献   
16.
Wide-angle seismic data along the Mantle Electromagnetic and Tomography (MELT) arrays show that the thickness of 0.5- to 1. 5-million-year-old crust of the Nazca Plate is not resolvably different from that of the Pacific Plate, despite an asymmetry in depth and gravity across this portion of the East Pacific Rise. Crustal thickness on similarly aged crust on the Nazca plate near a magmatically robust part of the East Pacific Rise at 17 degrees15'S is slightly thinner (5.1 to 5.7 kilometers) than at the 15 degrees55'S overlapping spreading center (5.8 to 6.3 kilometers). This small north-south off-axis crustal thickness difference may reflect along-axis temporal variations in magma supply, whereas the across-axis asymmetry in depth and gravity must be caused by density variations in the underlying mantle.  相似文献   
17.
AIM: To describe and enumerate conditions that interrupted training and racing in a population of Thoroughbred racehorses in New Zealand.

METHODS: A longitudinal study design was used to collect data on horses training under the care of 20 licensed racehorse trainers from venues in the mid to lower regions of the North Island between October 1997 and July 2000. Incidence rates were reported for first and second occurrences for different categories of musculoskeletal injury (MSI), and first occurrences of upper and lower respiratory tract disease, using training days as time-at-risk. The proportion of horses that retired or died due to MSI, respiratory tract or miscellaneous conditions was used to estimate risk of exit for each type of event. Duration of training preparation, starts per 100 training days, and proportion of starts that ended in first, second or third place, were calculated for horses at risk for first MSI, and all subsequent MSIs. In training preparations that had at least one start and that ended in MSI, the cumulative percentage of MSIs by day of diagnosis was reported for 0–21 days after the last start in the preparation.

RESULTS: Horses (n=1,571) were followed during 3,333 training preparations and 392,290 training days. Events associated with the end of a training preparation or spell period included MSI (n=834), respiratory event (RE; n=165), miscellaneous event (ME; n=58), and voluntary retirements (n=360). Causes of MSI included lameness (n=400), shin soreness (n=207), tendon and ligament conditions (n=98), injury or laceration (n=56), fractures (n=55), and back disorders (n=18). MSIs involved the limbs in 97% of cases, and the lower limbs up to the carpus or hock in the fore- and hindlimbs, respectively, in 81% of cases. Most (93%) lower limb conditions involved a forelimb while 70% of MSIs that involved structures above the carpus or hock involved a hindlimb. Incidence rates (IRs) are reported for each age group for first and second occurrences of MSI, and first occurrence of upper and lower respiratory tract disease. The risk of MSI was higher in horses that had incurred one previous MSI (RR 1.4, 95% CI=1.2–1.7; p>0.001) than in horses without any previous MSI. The proportion of horses that exited due to death or retirement varied with the type of injury, and the highest proportion was associated with recurrent fractures, and tendon and ligament injuries (46.2 and 44.4%, respectively). The overall IR of horses exiting the study due to retirement or death increased with increasing age, and was higher in females than males for horses aged 2, 3, 4, and ≥5 years. A reduction in the number of starts per 100 training days was observed in horses aged ≥5 years when returning to training after an initial MSI (p=0.004). Male horses of all age groups and females younger than 4 years had shorter median training preparations (p>0.05) when returning to training after an initial MSI compared with preparations at risk for a first occurrence of MSI. Between 27 and 62% of cases of MSI that occurred in training preparations after at least one start were reported on the day of the last start, and the remainder were reported in the days to weeks following the last start of that preparation.

CONCLUSION: Incidence rates, and proportions of affected horses that retired or died as a result of injury or disorder varied with type of injury and age of horse. Horses returning to training after an initial MSI were at higher risk of subsequent MSIs and showed changes in duration of training preparations, but little change in starts per 100 training days or probability of placing in each start. MSIs in racing horses were less likely to be reported on the day of a race than at other times in the training preparation for all ages except 2-year-olds.  相似文献   
18.
The lumbosacral-canal system in birds most likely operates as a sense organ involved in the control of balanced walking and perching, but our knowledge of it is superficial. Penguins constitute interesting objects for the study of this system due to their upright walking, but only the Humboldt penguin, Spheniscus humboldti, and some incomplete fossil penguin synsacra have been studied in this respect. Here, we give an integrative comparative insight into the synsacral canal of extant Emperor penguin, Aptenodytes forsteri, Adelie penguin, Pygoscelis adeliae, and Eocene giant Anthropornis and/or Palaeeudyptes Antarctic penguins, using computed tomography imaging and associated data-extraction methodologies, complemented by analytical approaches ranging from geometric morphometrics to modularity, curvature, and wavelet analyses. We document that the variability in the number of synsacro-lumbar vertebrae is evolutionarily conserved, and all studied synsacra possess osteological correlates of the lumbosacral-canal system. We also found that Eocene and extant Antarctic penguins were separable on the basis of the main direction of the shape-related (size-independent) variability within said system, and A. forsteri was unique in the entire studied set in terms of the relative cranial shift of this compound structure. Moreover, we suggest that the evolutionary processes, shaping both the terrestrial posture and gait, were responsible, in extant penguins, for the increased simplicity and stability of the synsacral canal cross-sectional periodic patterns, as well as pave the way for the lumbosacral-canal system modularity characterized by reduced atomization/complexity.  相似文献   
19.
In spite of widespread application of flutamide in the endocrine therapies of young and adult patients, the side effects of this antiandrogen on spermatogenesis and germ‐cell morphology remain unclear. This study evaluates the short‐term androgen blockage effect induced by the administration of flutamide to the testes of pubertal (30‐day old) and adult (65‐ and 135‐day old) guinea pigs, with an emphasis on ultrastructural alterations of main cell types. The testes removed after 10 days of treatment with either a non‐steroidal antiandrogen, flutamide (10 mg/kg of body weight) or a pharmacological vehicle alone were processed for histological, quantitative and ultrastructural analysis. In pubertal animals, flutamide androgenic blockage induces spermatogonial differentiation and accelerates testes maturation, causing degeneration and detachment of primary spermatocytes and round spermatids, which are subsequently found in great quantities in the epididymis caput. In post‐pubertal and adult guinea pigs, in addition to causing germ‐cell degeneration, especially in primary spermatocytes, and leading to the premature detachment of spherical spermatids, the antiandrogen treatment increased the relative volume of Leydig cells. In addition, ultrastructural evaluation indicated that irrespective of age antiandrogen treatment causes an increase in frequency of organelles involved with steroid hormone synthesis in the Leydig cells and a dramatic accumulation of myelin figures in their cytoplasm and, to a larger degree, in Sertoli cells. In conclusion, the transient exposition of the guinea pigs to flutamide, at all postnatal ages causes some degenerative lesions including severe premature detachment of spermatids and accumulation of myelin bodies in Leydig and Sertoli cells, compromising, at least temporarily, the spermatogenesis.  相似文献   
20.
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