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Results for “artificial selection”

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At least 685 records · Page 38Linked to original sources
PubMed2003

Diet influences the ecology of lactic acid bacteria and Escherichia coli along the digestive tract of cattle: neural networks and 16S rDNA.

In this manuscript, the authors have sought to gain a better understanding of the interactions between Escherichia coli and lactic acid bacteria (LAB) isolated from Rogossa MRS agar along the digestive tract of grain- and forage-fed cattle. E. coli from cattle receiving a high-grain diet were more numerous (P<0.05) than from the high-forage diet and the highest numbers were in the faeces. Isolates on Rogossa MRS agar were always greater in the high-grain diet (P<0.05) and contained a significant number of LAB. A random set of Rogossa MRS agar colonies was selected and artificial neural networks were used to develop a relationship between colony description and species which was validated using sequence analysis (16S rDNA). The neural networks correctly predicted species in more than 80 % of cases and was composed, primarily, of Lactobacillus vitulinus, Lactobacillus ruminis, Selenomonas ruminantium, Streptococcus bovis, Acidaminococcus fermentans and Megasphaera elsdenii. In conjunction with statistical diversity indices, it was demonstrated that diversity in the high-fibre diet was always lower and was a consequence of the dominance of Str. bovis. In contrast, the diversity in the high-grain diet was greater (P<0.05) and was a consequence of the decline in Str. bovis. These data demonstrate that there is a positive relationship between coliform and LAB isolates throughout the digestive tract of cattle, and diet is the major factor regulating bacterial composition.

Animal Feed↗
PubMedDate not supplied

Ultrasonography revealing the accumulation of rete testis fluid in bull testicles.

Ultrasonography was used for diagnosing accumulation of rete testis fluid in live bulls. When 447 bulls of Ayrshire breed selected for artificial insemination were studied by ultrasonography, eleven were detected in which the ultrasonograms visualized accumulation of rete testis fluid in the testicles. In 7 bulls the accumulation (spermiostasis) was bilateral and in 4 unilateral. In only four out of 18 testicles, macroscopically epididymal cysts were seen after slaughter. At the age of 16 months four bulls with bilateral spermiostasis were azoospermic. When studied by ultrasonography, the rete testis of normal testicles was echogenic and narrow but in affected testicles anechogenic and wide. Nine of the affected bulls were sons of three fathers. We suggest that spermiostasis is hereditary in Ayrshire bulls and, as in the goat, is progressive by nature.

Animals↗
PubMed1998

Articular cartilage: injuries and potential for healing.

Impact and torsional joint loading can injure articular cartilage, causing pain, joint dysfunction and effusions, and, in some instances, progressive joint degeneration. Differences in the type of injury and the repair response distinguish three classes of articular surface injuries: 1) damage to the joint surface that leaves the articular surface intact but causes internal chondral damage and may cause subchondral bone injury, 2) mechanical disruption of the articular surface limited to articular cartilage, and 3) mechanical disruption of articular cartilage and subchondral bone. A variety of treatments has the potential to improve healing of articular surfaces, including perforation of subchondral bone, altered joint loading, periosteal and perichondrial grafts, cell transplantation, growth factors, and artificial matrices. Selection of treatment for a patient with an articular cartilage injury should be guided by an understanding of the type of injury, the potential for healing, and the effects of treatment on joint surface restoration.

Animals↗
PubMed1999

[Research on cause of distinction in antiendotoxic activation of radix isatidis from different cultivated populations].

OBJECTIVE: To research into the cause of distinction in antiendotoxic activation of Radix Isatidis from different cultivated populations. METHOD: 19 samples of Radix Isatidis were gathered. 12 portions of seeds were cultivated in the same field in Shanghai, and the selected and artificially bred autotetraploid seeds were planted in 5 different locations. All the samples were compared through antiendotoxic experiment. RESULTS: There are some marked distinction among the 19 samples from different populations. The distinction of the 12 samples cultivated in the same field didn't disappear. The activation of autotetraploid from 5 different locations didn't vary on the whole. CONCLUSION: Germplasm is the main factor to cause activation distinctions of Radix Isatidis, while environment is less important.

Drugs, Chinese Herbal↗
PubMedDate not supplied

Intercommissural width in 4 racial groups as a guide for the selection of maxillary anterior teeth in complete dentures.

PURPOSE: To determine whether intercommissural width is a reliable guide for the selection of maxillary denture teeth width. MATERIALS AND METHODS: Casts were made of 160 subjects from 4 different racial groups. Locations of intercommissural width landmarks (the corners of the mouth) were made on the subjects and transferred to the casts. The distances between the corners of the mouth and the distal of the canines were measured on the casts and compared. RESULTS: A weak correlation was found between the distal of the canines and the distance between the corners of the mouth in the 4 racial groups. CONCLUSION: The use of the corners of the mouth for the selection of artificial teeth is generally inaccurate.

Adolescent↗
PubMed1991

[A case of ruptured distal arch aneurysm associated with postoperative unilateral respiratory disorders].

This paper describes a patient with ruptured distal arch aneurysm associated with postoperative unilateral respiratory disorders whose life was able to be saved by surgery. The patient was a 68-year old male who underwent emergency surgery due to sealed rupture of distal arch aneurysm while preparing for selective surgery. Artificial graft replacement of the distal arch was carried out under centrifugal pump bypass. Respiration was controlled using differential lung ventilation (DLV) techniques. This was done because weaning from the respirator was difficult due to decreases in lung-thorax compliance on the opened chest side after surgery. Weaning from the respirator was achieved on the 10th day of illness after surgery. Postoperative prognosis of ruptured thoracic aneurysm is extremely poor, with high mortality being attributable to the fact that most patients are elderly and the incidence of respiratory and cardiovascular complications is very high. In addition, problems are often encountered in postoperative respiration management in patients with thoracic aneurysm who need open chest surgery. DLV seems to be a useful support in such patients who have underlying respiratory disorders.

Aged↗
PubMed1990

[Current diagnosis of impotence].

In recent years the true incidence of impotence due to organic diseases in comparison with psychogenic disorders could be verified. New diagnostic tools as penile Doppler ultrasonography, PBI estimation, NPT measurement, invasive SKIT's, neurophysiological methods, selective phalloarteriography, artificial erection and dynamic cavernosography are introduced and are the guide to therapeutic approach.

Adult↗