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41.
Faecal samples from 111 cats with diarrhoea that were living in the UK were submitted for the assessment of Tritrichomonas foetus infection by polymerase chain reaction (PCR). Sixteen (14.4%) samples were found to be positive. In agreement with studies from the USA, infected cats were predominantly of a year of age or less and of a pedigree breed, with Siamese and Bengal cats specifically over-represented in this population.  相似文献   
42.
The magnitude of the axial pressure gradient at 77 degrees K (11 percent per centimeter) in solid methane compressed along one axis for applied pressures up to 10 kilobars was determined by comparing the electrical resistance of a pair of doped tellurium pressure gages with that of a set of single-crystal gages made of high-purity bismuth. The existence of the pressure gradient revealed the causes of deformation in metal tensile specimens embedded in solid methane and cycled to high pressure.  相似文献   
43.
Rod-cone interactions: different color sensations from identical stimuli   总被引:1,自引:0,他引:1  
Different color sensations were generated by two areas in a complex scene, even though both areas sent to the eye the same 656-nanometer radiance that excited the long-wave cones and excited only the rods.  相似文献   
44.
During the 1988, 1989 and 1990 growing seasons, canopy and air temperatures, solar and net radiation, relative humidity and wind speed were measured at 10 minute intervals during daytime hours in a field of wellwatered Russet Burbank potatoes in southeast Idaho. A linear relationship between canopy temperature minus air temperature and vapor pressure deficit (TC-TA = 0.2 -2.0 VPD) was developed for use in the Crop Water Stress Index (CWSI). Values of CWSI for well-watered potatoes were generally in the -0.4 to 0.4 range, and exhibited a diurnal trend of decreasing values towards midday and increasing values during the afternoon. Wind speed appeared to increase the CWSI and may account for some of the observed variability.  相似文献   
45.
Various potato cultivars were grown in field plots from seed pieces inoculated withCoryneacterium sepedanicum by vacuum infiltration. Foliage symptoms were recorded during the growing season and tuber symptoms at harvest. Cultivars were ranked according to the frequency with which the progeny tubers expressed external bacterial ring rot symptoms. Those that yielded 50–100% symptomatic tubers were placed in symptom expression class (SEC) 1; those that produced 25–49%, 10–24%, and ≤9% symptomatic tubers were placed, respectively, in SEC 2,3, and 4. The incidence of latent ring rot infections in stems and tubers were similar among cultivars in the different SEC classes. Bacterial population densities, quantified by immunofluorescence, were as high as 1010 cells/g in stems from cultivars of all SEC classes. Mean populations in tubers ranged from 106 – 107 cells/g and did not differ significantly among cultivars.  相似文献   
46.
To establish the prevalence, patterns and risk factors of animal-related injuries among veterinarians, self-administered questionnaires were given to 60 veterinarians practicing in metropolitan Kampala. The prevalence of animal-related injuries in metropolitan Kampala was 72% (95%CI, 57~84). Some veterinarians (34%) suffered multiple injuries with a mean and median of 2.1 and 2.0 injuries per veterinarian, respectively. Of a total of 70 self-reported animal related injuries, cattle accounted for 72%, cats for 25%, dogs for 23%, self inoculation for 15% and birds for 13%. Injuries associated with poultry did not require hospital treatment. The upper limb was the most the frequently (68%) injured anatomical body part of veterinarians, and vaccination of animals (25%) was the major activity associated with injury. Animal-related injuries are common among practicing veterinarians in metropolitan Kampala; however, they did not differ significantly based on the veterinarian''s gender, experience or risk awareness.  相似文献   
47.
In 2018, Vagococcus salmoninarum was isolated from two lots of broodstock “coaster” brook trout (Salvelinus fontinalis) containing ~1,500 fish at the Iron River National Fish Hatchery, at which time it was identified as the causative agent of a chronic coldwater streptococcosis epizootic. Clinical signs included exophthalmia, lethargy, erratic swimming and loss of equilibrium. Female fish experienced disproportionately higher morbidity and mortality than male co-inhabitants, and routinely retained eggs following spawning. The most consistent gross clinical sign was heart pallor and turbid pericardial effusion. An attempted treatment using florfenicol was ineffective at halting the epizootic, which spanned more than a year and resulted in >50% mortality before remaining fish were culled. As there is no previous documentation of V. salmoninarum at this hatchery or in this species, it is still unclear what circumstances led to this epizootic. The inability to treat this chronic disease led to the loss of valuable broodstock, hampering ongoing fishery conservation efforts in the Great Lakes Basin.  相似文献   
48.
Vagococcus salmoninarum was identified as the causative agent of a chronic epizootic in broodstock “coaster” brook trout (Salvelinus fontinalis) at the Iron River National Fish Hatchery. The epizootic spanned more than a year, was unresponsive to multiple florfenicol treatments, and resulted in >50% mortality of the affected fish. The decision was made to cull the remaining fish during spawning, which presented an opportunity to more thoroughly examine V. salmoninarum sampling methods, organ tropism and vertical transmission. A newly developed qPCR targeting the pheS gene was used in concert with bacterial culture to show that V. salmoninarum indeed disproportionately affects females and has a tropism for female reproductive tissues. The study demonstrates that some female reproductive tissues (e.g. ovarian fluid, unfertilized eggs) are also an effective option for non-lethal detection. Despite the widespread presence of V. salmoninarum in ovarian fluid and on egg surfaces, we found no evidence of intra-ova transmission.  相似文献   
49.
Twelve horses were utilized in a 2 × 2 factorial experiment to investigate the proportionality of the skeleton (small and large framed) and musculature (light and heavy) of mature horses. Large framed horses were longer from the elbow to fetlock, knee to fetlock, hock to fetlock, and from the poll to the end of the nasal bone than small framed horses. Withers height was correlated (P<.001) with the lengths of all long bones (r=.85 to .95) with the exception of the metacarpal bone (r=.69, P<.05). Yet when the lengths of the head, legs, scapula, humerus, femur, tibia, metacarpal, and metatarsals were expressed as a percentage of withers height, no differences between frame sizes were observed.The heavily muscled horses had greater (P<.05) rear quarter width, forearm circumference, gaskin circumference, head width and length than did the lightly muscled horses. The weights of the extensor carpi radialis, biceps femoris, and total round muscle were greater for the heavily muscled horses. Correlations (P<.001) between the weights of the biceps femoris and the total round muscle, total round tissue, and gaskin circumference ranged from .89 to .94 while correlations (P<.001) of the biceps femoris weight with quarter width and extensor carpi radialis were .83 and .82, respectively.Cannon wall area and circumference measurements did not differ for frame size or the degree of muscling but a correlation (r=.75, P<.01) was noted between the cannon circumference taken on the live horses and the actual circumference of the large and small metacarpals.The demonstrated relationship between the lengths of the long bones and height of a horse indicate little value for many of the traditional conformation guidelines governing selection of the ideal conformation horse. Horsemen should realize that many body lengths such as elbow to fetlock actually represented a relatively constant percentage of withers height. Lengths of the scapula, humerus, metacarpal, femur, and tibia also reflected a constant relationship with withers height. The correlations between the extensor carpi radialis and the biceps femoris weights refute the common belief that horses may naturally (no forced exercise) be more heavily muscled in either the fore or rear quarter. Therefore, the data support the theory of proportionality relative to the conformation of the skeletal size and muscling of predominantly Quarter Horse bred horses.  相似文献   
50.
Obtaining reliable results from comparative crustacean nutrition studies requires a dietary reference protein which is available world-wide and is nutritionally optimal for growth and survival. Traditional protein sources include "vitamin free" casein, egg albumin, whole egg protein, soybean protein, and others. These have proven to be inadequate for juvenile lobster ( Homrus americanus ). Purified rock crab ( Cancer irroratus ) protein is proposed to be nutritionally superior to casein for inclusion in semi-purified lobster diets.
Eighteen week feeding trials with juvenile H. americanus were conducted to compare diets containing protein obtained from rock crabs ( Cancer irroratus ), and produced by several different purification processes with a control diet having casein as its primary protein source. Diets containing purified rock crab protein were found to be superior to the control diet. Among the differently derived purified rock crab protein products, the precooked, isopropanol-purified was the most effective dietary ingredient.  相似文献   
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