Molecular evolution: macromolecular sequences in systematics and evolutionary biology     

Aquadro CF 《Science (New York, N.Y.)》1983,221(4606):147-148

  相似文献   

A fossil noctuid moth egg from the late cretaceous of eastern north america     

Gáll LF  Tiffney BH 《Science (New York, N.Y.)》1983,219(4584):507-509

A moth egg assignable to the family Noctuidae (Lepidoptera) is described from 75-million-year-old sediments from Martha's Vineyard, Massachusetts. This sample, which extends the fossil record of this farnily and modern heteroneuran moths back to the Cretaceous, may provide insight into the coevolution of moths and flowering plants, as well as have implications for the evolution of bats.  相似文献   

Spasmodic tremor and possible magma injection in long valley caldera, eastern california     

Ryall A  Ryall F 《Science (New York, N.Y.)》1983,219(4591):1432-1433

Intensive microearthquake swarms with the appearance of volcanic tremor have been observed in the southwest part of Long Valley caldera, southeastern California. This activity, possibly associated with magma injection, began 6 weeks after several strong (magnitude 6+) earthquakes in an area south of the caldera and has continued sporadically to the present time. The earthquake sequence and magmatic activity are part of a broad increase in tectonic activity in a 15,000-square-kilometer region surrounding the "White Mountains seismic gap," an area with high potential for the next major earthquake in the western Great Basin.  相似文献   

Congenital esophagotracheal fistula as the cause of bloat in a calf     

Keane DP  Horney FD  Ogilvie TH 《The Canadian veterinary journal. La revue veterinaire canadienne》1983,24(2):57-59

A four day old Holstein calf was presented with a history of recurrent free gas bloat. An exploratory laparotomy was performed and no abnormalities were discovered in the gastrointestinal tract. An esophagotracheal fistula was suspected and confirmed by endoscopy. Surgical correction was performed by ligating the tubular connection between the trachea and esophagus and suturing closed the defects in these structures.  相似文献   

Examination of the origin of increased equine serum alkaline phosphatase concentrations   总被引：2，自引：0，他引：2  

Trueman KF  Lumsden JH  McSherry BJ 《The Canadian veterinary journal. La revue veterinaire canadienne》1983,24(4):108-111

Serum alkaline phosphatase activity was found to be increased in 32.6% of equine samples analyzed at the Ontario Veterinary College over an 18 month period. An attempt was made using sensitivity to L-phenylalanine and heat to identify the origin of increased serum alkaline phosphatase isoenzymes present in 44 clinical cases. No difference in sensitivity to either procedure was observed for serum alkaline phosphatase from groups of foals and horses representing different clinical problems. Alkaline phosphatase of osseous tissue origin appeared to be the major source of activity for each group of animals reported.  相似文献   

Clostridial myositis following ivermectin administration          下载免费PDF全文

Nation PN  Frelier PF  Schoonderwoerd M 《The Canadian veterinary journal. La revue veterinaire canadienne》1983,24(9):295

  相似文献   

The F38-Like Group,a New Group of Caprine Mycoplasmas?     

H. Ern   R. H. Leach  M. M. Salih  K. J. MacOwan 《Acta veterinaria Scandinavica》1983,24(3):275-286

This paper concerns the taxonomic status of the F38-like group (MacOwan), a prime determinant of contagious caprine pleuropneumonia (CCPP). Extensive biochemical and serological investigations on strain F38 are reported. Some complex serological relationships with other mycoplasma species are revealed. The results, taken in conjunction with earlier published work on geno-typic characters, lead to the conclusion that final classification of these organisms should await further comparative studies of a number of field strains with a related group of strains classified as M. capri-colum.The characterization of F38 confirms its partial relationship to the “M. mycoides group” of ovine/caprine/bovine mycoplasmas, and has also revealed a very close phenotypic relationship to the bovine mycoplasma serogroup 7, a finding of potential diagnostic and epidemiological importance.Key words: mycoplasmas, classification, F38-like group  相似文献   

Endocrine effects of heat stress in boars   总被引：1，自引：0，他引：1  

K. Larsson  S. Einarsson  K. Lundstrm  J. Hakkarainen 《Acta veterinaria Scandinavica》1983,24(3):305-314

The purpose of this study was to describe the temporal changes in peripheral plasma levels of testosterone and Cortisol in boars during and after heat stress. A total of 8 boars were utilized, 4 of them were exposed to 35°C, for 100 h in a climatic room, and 4 served as controls and were kept at 20 °C for 100 h in the climatic room.Blood samples were obtained via permanent vein catheters 3 times daily from 5 days before heat stress until 20 days after termination of heat stress. Testestorone levels were determined by radioimmunoassay and Cortisol by a competitive protein binding technique.For both hormones the pre-exposure levels were similar in both groups of boars. The control boars had significantly higher testosterone levels, while being in the climatic room, than during any other period. The experimental boars had slightly increased testosterone levels during the first day of heat stress and thereafter continuously decreased levels. In the control boars the testosterone levels returned to pre-exposure levels immediately after removal from the climatic room, whereas in the experimental boars the testosterone levels were dramatically increased during the first 5 days after exposure. The differences in Cortisol levels, between the 2 groups of boars were restricted to the period spent in the climatic room. During this period the experimental boars had significantly higher Cortisol levels.Key words: boars, heat stress, testosterone, cortisol  相似文献   

An Epidemiological Study of Foot Rot in Pastured Cattle     

J. Monrad  A. A. Kassuku  P. Nansen  P. Willeberg 《Acta veterinaria Scandinavica》1983,24(4):403

Using 12 years of data from the common grazing areas at Store Vildmose on the incidence of foot rot in cattle, it was shown that the disease incidence varied significantly between the sections in which the animals were grazing. Differences also existed between breeds in their foot rot incidence. Extraordinarily wet summers were noted to influence foot rot in cattle, and a possible effect of soil pH was also observed.Key words: foot rot, cattle, incidence, epidemiology, breed differences, climatic factors, lameness  相似文献   

Comparison of plasma aldosterone concentration among clinical status groups of dogs with chronic heart failure     

Knowlen GG  Kittleson MD  Nachreiner RF  Eyster GE 《Journal of the American Veterinary Medical Association》1983,183(9):991-996

The plasma aldosterone concentration (PAC) among clinical status groups of 23 dogs with chronic heart failure was compared at various times after diagnosis of the problem. Eighteen dogs admitted in New York Heart Association (NYHA) class IV clinical status had significant elevations in PAC (P<0.0001), when compared with clinically normal dogs. Five dogs admitted in NYHA class III status and 4 dogs that responded with a change to NYHA class III status had significant elevations in PAC (P<0.01), when compared with clinically normal dogs. In patients with NYHA class IV status, the PAC was significantly greater (P<0.01) than in patients in NYHA class III status. For patients with the poorest prognosis, ie, severe signs of NYHA class IV status, the PAC was not markedly different, when compared with that for patients with a favorable prognosis, ie, recent onset of signs of NYHA class IV status. Patients treated with captopril had significantly lower PAC after therapy (P<0.01), whereas patients treated with hydralazine had significantly higher PAC (P<0.05) after therapy. It was concluded that heart failure in the dog increases PAC, most likely because of renin-angiotensin-aldosterone-system activation, and that the increase is related directly to the clinical status of the patient. Further, it was concluded that treatment of dogs in heart failure with captopril causes a decrease in circulating PAC, whereas treatment with hydralazine causes an increase in circulating PAC.  相似文献