David L. Brown and Kai A. Schafft: Rural people and communities in the twentyfirst century: resilience and transformation     

Lauren Renée Moore 《Agriculture and Human Values》2014,31(4):687-688

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Phenolic compounds in plant disease resistance   总被引：1，自引：0，他引：1  

ulrich matern  richard e. kneusel 《Phytoparasitica》1988,16(2):153-170

We propose that an important first line in plant defense against infection is provided by the very rapid synthesis of phenolics and their polymerization in the cell wall. This rapid synthesis, which leaves no time forde novo enzyme synthesis, is regulated by the extreme pH-dependence of the hydroxylase, catalyzing the formation of caffeoyl-CoA from 4-coumaroyl-CoA. We further propose that elicitor treatment or infection causes rapid membrane changes leading to a decrease in cytoplasmic pH. This decrease would have the effect of activating the hydroxylase.  相似文献   

Microvascular development and growth of uterine tissue during the estrous cycle in mares     

Ferreira-Dias GM  Serrão PM  Durão JF  Silva JR 《American journal of veterinary research》2001,62(4):526-530

OBJECTIVE: To document uterine growth and microvascular development in the endometrium of uteri with differing degrees of fibrosis as well as uterine growth throughout the estrous cycle of mares. ANIMALS: 30 mares. PROCEDURE: Uterine tissue was obtained during the breeding season from a slaughter facility. Stage of estrous cycle of the mares was assessed on the basis of ovarian structures and plasma progesterone concentrations. Endometrium was characterized by use of light microscopy, and blood vessel walls were marked by histochemical techniques. Microvascular development was evaluated by a computerized image analysis system. Growth of uterine tissue was based on cellular content of DNA and RNA, RNA:DNA, and protein:DNA. RESULTS: Significant differences in vascular density were not observed in the endometrium of uteri obtained from mares euthanatized during the follicular or luteal phase of the estrous cycle, regardless of whether endometrial classification of degree of fibrosis was considered. There was a 3-fold increase in amount of DNA and RNA of endometrial cells in the follicular phase when compared to myometrium. Hypertrophy of endometrial tissue during the luteal phase was reflected by a significant increase in cell protein content and protein:DNA. CONCLUSIONS AND CLINICAL RELEVANCE: Endometrial growth of vascular tissues during the estrous cycle may be coordinated with development of nonvascular tissue. Estrogen and progesterone may play a role in regulation of uterine growth and angiogenesis.  相似文献   

Relation between Physical Properties of the Zona Pellucida and Viability of Bovine Embryos after Slow-freezing and Vitrification   总被引：4，自引：0，他引：4  

F Moreira da Silva  R Metelo 《Reproduction in domestic animals》2005,40(3):205-209

In vitro-produced bovine morulae/blastocyst embryos (n = 119) were slow-frozen and vitrified and the physical alterations of the zona pellucida (ZP) was observed by scanning electron microscopy (SEM) to find an explanation for the loss of developmental capacity of the embryos after freezing/thawing. A control group was provided, in which embryos (n = 38) were neither frozen nor vitrified. Embryos were in vitro-cultured in a standard CO2 Heraeus incubator and their viability was assessed 24 and 48 h after the start of culture, evaluating their morphological aspect. After 24 h of culture, embryo survival rate for slow-freezing/thawed (n = 23), vitrified/thawed (n = 20) and control embryos (n = 20) was 39, 27 and 90%, and 35, 14 and 65% after 48 h of culture, respectively. For evaluation of physical changes occurring in ZP, 20 embryos were slow-frozen, 18 were vitrified and 18 were used as control. All embryos were fixed, dried and examined under an SEM. Embryo's diameter, as well as the number of pores and their diameter was measured in squares of 6.4 microm width. We observed that, on average, the diameter of the embryos (92.26 +/- 10.15 microm) did not differ significantly among all embryos. As far as the diameter of the pores in the outer surface of the ZP is concerned, the results revealed a significant difference (P < 0.05) between control (0.48 +/- 0.0025 microm), slow-frozen (0.34 +/- 0.0007 microm) and vitrified (0.27 +/- 0.0006 microm) embryos. For the number of pores, statistical differences (p < 0.05) were observed between control and vitrified embryos (45.4 +/- 7.3 vs 38.2 +/- 8.2). It is possible that ZP functions as a barrier which is positive when dealing with pathogens, but is harmful when nutrients were supplied from the outside, especially at 48 h of culture. Results indicate that the steps of cryopreservation cause alterations in ZP, with irreversible damage on the further developmental competence of bovine embryos.  相似文献   

Coagulase gene typing of Staphylococcus aureus isolated from cows with mastitis in southeastern Brazil          下载免费PDF全文

Elizabete Rodrigues da Silva  Nivaldo da Silva 《Canadian journal of veterinary research》2005,69(4):260-264

A typing procedure based on polymorphism of the coagulase gene (coa) was used to discriminate Staphylococcus aureus isolated from Minas Gerais dairy cows with mastitis. Amplification of the gene from the 64 S. aureus isolates produced 27 different polymerase chain reaction (PCR) products; 60 isolates showed only 1 amplicon, and 4 showed 2 amplicons. The isolates were grouped into 49 types by analyzing the restriction fragment length polymorphism (RFLP) of the coa gene; the 10 most common types accounted for 39% of the isolates. The results demonstrate that many variants of the coa gene are present in the studied region, although only a few predominate.  相似文献   

Bacterial and fungal pathogens isolated from corneal ulcerations in domesticated elephants (Elephas maximus maximus) in Sri Lanka     

Kodikara DS  De Silva N  Makuloluwa CA  De Silva N  Gunatilake M 《Veterinary ophthalmology》1999,2(3):191-192

Infective corneal diseases are common among the domesticated elephants in Sri Lanka, causing morbidity including blindness leading to loss of revenue to their owners. From 140 elephants of different ages and both sexes, 36 animals (25.7%) had evidence of keratitis, corneal ulcers, corneal opacities, and some had foreign bodies in their eyes. Nine elephants (6.4%) had lesions in both eyes (6.41%). Cultures for both bacteria and fungi were obtained from 26 corneal ulcers, including the nine elephants with bilateral lesions. The other 10 animals could not be restrained for sample collection. Swabs from the normal corneas of an additional 20 elephants without signs of any ophthalmic diseases were also collected. Twenty-three of the 35 (65.71%) samples from affected corneas yielded bacterial pathogens, and 14 (40%) also had fungal isolates. None of them yielded a fungal isolate alone. The predominant bacteria isolated were Staphylococcus aureus , beta hemolytic streptococci and coliforms. Fusarium , Cladosporium , Curvularia and Aspergillus species were the primary fungal isolates. No bacteria or filamentous fungi were isolated from the eyes with the normal corneas. Microbial identification including fungal isolations is suggested in the management of infective corneal diseases in elephants.  相似文献   

Estrogen content of feces of newborn calves     

R Satrapa  E Grunert  C A Silva 《DTW. Deutsche tier?rztliche Wochenschrift》1973,80(8):179-181

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Studies on Salmonella Infection in Fattening Calves1     

P. A. M. Guine  W. Edel  E. H. Kampelmacher 《Zoonoses and public health》1967,14(2):163-169

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Salmonella Infections in Pigs fattened with Pellets and Unpelleted Meal1     

W. Edel  P. A. M. Guine  M. van Schothorst  E. H. Kampelmacher 《Zoonoses and public health》1967,14(5):393-401

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Some aspects of crop variation in ‘Golden Delicious’ apple trees     

J.M. Silva  M.E. Holgate  D.L. Abbott 《Scientia Horticulturae》1980,13(1):27-32

Fruit-set of ‘Golden Delicious’ apple trees was found to be largely independent of seasonal differences and much more closely related to the initial number of blossom clusters, when compared with many other apple cultivars under English conditions. In one young orchard, yield became increasingly a function of trunk girth during the first 3 cropping-years, but the trees then abruptly developed a biennial rhythm. Thereafter, blossom production was negatively correlated with the number of clusters in the previous year rather than with the number of fruits.Applications of daminozide or GA₃ appeared to increase or decrease, respectively, the amount of return bloom without altering the negative correlation with the number of clusters in the previous year. Chemical fruit-thinning with a mixture of carbaryl and NAA also appeared to be effective in increasing return bloom.  相似文献