A neural basis for general intelligence

Universal positive correlations between different cognitive tests motivate the concept of "general intelligence" or Spearman's g. Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal, and perceptuo-motor tasks with high-g involvement are compared with matched low-g control tasks. In contrast to the common view that g reflects a broad sample of major cognitive functions, high-g tasks do not show diffuse recruitment of multiple brain regions. Instead they are associated with selective recruitment of lateral frontal cortex in one or both hemispheres. Despite very different task content in the three high-g-low-g contrasts, lateral frontal recruitment is markedly similar in each case. Many previous experiments have shown these same frontal regions to be recruited by a broad range of different cognitive demands. The results suggest that "general intelligence" derives from a specific frontal system important in the control of diverse forms of behavior.     

Use of fetal skeletal mineralization for prediction of parturition date in cats

OBJECTIVE: To determine the relationship between parturition date and fetal skeletal mineralization detected radiographically in cats. DESIGN: Prospective clinical trial. ANIMALS: 31 queens and their 49 pregnancies. PROCEDURE: Seventeen pregnant queens were radiographed with a computed radiography system every 2 to 3 days from 1 week after pregnancy was identified by abdominal palpation until parturition. Radiographs were evaluated to determine the first identifiable mineralization of 16 bony structures and teeth during each pregnancy. This information was used to establish a table of expected parturition dates on the basis of fetal mineralization. Single radiographs from an additional 32 pregnant cats were evaluated, and predictions of parturition dates were made on the basis of the mineralization table. RESULTS: Mineralization was first detected 25 to 29 days prior to parturition (dpp). Mineralization was determined for the spinal column (22 to 27 dpp), skull (21 to 27 dpp), ribs (20 to 25 dpp), scapula (17 to 24 dpp), humerus (20 to 24 dpp), femur (19 to 23 dpp), radius (15 to 22 dpp), tibia (15 to 21 dpp), ulna (5 to 21 dpp), pelvis (8 to 20 dpp), fibula (0 to 17 dpp), tail (8 to 16 dpp), metacarpals and metatarsals (3 to 14 dpp), phalanges (0 to 11 dpp), calcaneus (0 to 10 dpp), and teeth (1 to 6 dpp). Date of parturition was predictable within 3 days in 75% of cats. CONCLUSIONS AND CLINICAL RELEVANCE: Identification of bony structures in the fetus is useful in estimating the time to parturition in queens.     

The carry-over of Campylobacter isolates between sequential poultry flocks

The carry-over of Campylobacter strains from one flock to a subsequent flock in the same broiler house has been studied using molecular epidemiological techniques. In all, 524 Campylobacter strains, isolated from two sequential broiler flocks from 60 broiler houses, were typed by restriction fragment polymorphism of the polymerase chain reaction (PCR) product of the flaA and flaB genes (fla typing). Selected strains were also typed using pulsed field gel electrophoresis (PFGE). By fla typing, 15 (21%) of the 60 houses with Campylobacter-positive sequential flocks had identical genotypes. In 10 (16% overall) of these houses the strains were also identical by PFGE. The difference in PFGE patterns in the strains from the three remaining houses may be indicative of genetic instability. Overall, these results suggest that carry-over from one flock to a subsequent flock in the same house is a relatively infrequent event and, therefore, that routine broiler house cleansing and/or disinfection is largely adequate to eliminate Campylobacter contamination. An alternative explanation of the low level carry-over is a persistent source or reservoir, external to the environment of the broiler houses.     

弯曲杆菌的流行病学、生态学及其可能的控制方法

由于生物安全措施最多只能预防弯曲杆菌的传染,仅仅起到推迟感染的目的。因此,今后需要在整个食品生产链采取新型和持续的干预措施解决弯曲杆菌的传染问题。     

Esophageal transit of capsules in clinically normal cats

OBJECTIVE: To evaluate the esophageal passage of capsules in clinically normal cats and determine the incidence of prolonged transit or entrapment. ANIMALS: 12 clinically normal adult cats. PROCEDURE: Esophageal transit of barium sulfate-filled capsules was evaluated fluoroscopically. Each cat was examined 3 times (36 examinations). Esophageal transit times were classified as normal (< or = 30 seconds) or prolonged (> 30 but < or = 240 seconds). Capsules were considered entrapped when transit times were > 240 seconds. RESULTS: Transit times were normal in 10 of the 36 (27.8%) examinations, whereas times were prolonged in 7 (19.4%) examinations. Capsules became entrapped in the midcervical region of the esophagus during 19 (52.8%) examinations. Following termination of each examination, cats with entrapped capsules were fed a small amount (0.5 to 1 ounce) of food; this resulted in passage of the capsule to the stomach. CONCLUSIONS AND CLINICAL RELEVANCE: The possibility of medication-induced esophagitis should be considered when orally administering ulcerogenic drugs to cats. It is recommended that a small volume of food be given following medications to ensure complete esophageal clearance.     

Fatal Myocardial Degeneration in an Adult Quarter Horse with Vitamin E Deficiency

A carcass of an adult female Quarter Horse that spontaneously died was received for general investigation at the veterinary diagnostic laboratory of North Dakota State University. Routine necropsy examination demonstrated multiple pale and firm foci in the heart that were histologically consistent with severe myocardial degeneration/necrosis and fibrosis. Analysis of a liver sample confirmed a suboptimal vitamin E level and a selenium value that was within reference range. Because there was no anamnestic indication for ingestion of cardiotoxic plants or evidence of other etiologic factors, vitamin E deficiency was concluded to have led to the development of the myocardial lesions, which precipitated acute heart failure resulting in sudden death.