Respiratory exposure to lead: epidemiological and experimental dose-response relationships   总被引：2，自引：0，他引：2  

J R Goldsmith  A C Hexter 《Science (New York, N.Y.)》1967,158(797):132-134

Epidemiologic studies of blood lead levels in general and occupational groups show a logarithmic regression on estimated atmospheric exposure. Experimental results at the same and higher levels show a dose-response relationship which fits the same regression. The data imply that long-term increases in atmospheric lead will result in predictably higher blood lead levels in the exposed populations.  相似文献   

Spatial Variability of Turbulent Mixing in the Abyssal Ocean   总被引：3，自引：0，他引：3  

KL Polzin  JM Toole  JR Ledwell  RW Schmitt 《Science (New York, N.Y.)》1997,276(5309):93-96

Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise. The diapycnal diffusivity there was estimated to be less than or approximately equal to 0.1 x 10(-4) meters squared per second. In contrast, mixing rates are large throughout the water column above the rough Mid-Atlantic Ridge, and the diffusivity deduced for the bottom-most 150 meters exceeds 5 x 10(-4) meters squared per second. Such patterns in vertical mixing imply that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.  相似文献   

Virginia barrier island configuration: a reappraisal     

Leatherman SP  Rice TE  Goldsmith V 《Science (New York, N.Y.)》1982,215(4530):285-287

The 12 Virginia barrier islands are divided into three groups on the basis of historical retreat rates and characteristics. The growth and reversal of inlet offsets is a long-term event that results from the operation of known coastal processes. Both geomorphic evidence and wave refraction analyses indicate that shoreline irregularity will diminish with time. There is no basis for the prediction (or expectation) that cape-like features will evolve along this shoreline.  相似文献   

A COMPARISON OF MANUAL AND AUTOMATIC ULTRASOUND-GUIDED BIOPSY TECHNIQUES     

FREDRIK E. HOPPE  DVM  PHD  DAVE A. HAGER  DVM    PAUL W. POULOS  JR.  DVM PHD  STINA EKMAN  DVM    P. G. LINDGREN  MD  PHD 《Veterinary radiology & ultrasound》1986,27(4):99-101

A manual, ultrasound-guided biopsy technique was compared to a new automatic method using a new biopsy device. The liver and the left kidney of 10 dogs were biopsied using the two methods. The specimens from the biopsies were compared for size and quality. Results demonstrate that larger and higher quality samples were obtained with the new automatic method.  相似文献   

Persistent corneal erosion in an Australian dingo     

AG TURNER  JR PHELAN 《Australian veterinary journal》1996,74(6):435-436

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Use of dairy herd improvement monthly summary data to monitor intervention strategies in a dairy herd experiencing suboptimal reproductive performance and reduced milk production     

K H Hoblet  M L Eastridge  C S Hayhow  P D Goldsmith  J R Staubus 《Journal of the American Veterinary Medical Association》1991,198(6):1028-1034

An 87-cow dairy herd with a history of high milk production was visited because of reduced reproductive performance and decreasing milk production. Cows that had recently delivered calves were thin, and many cows had evidence of previous episodes of laminitis. A ration that provided an unfavorable forage-to-concentrate ratio was being fed. In addition to various diagnostic efforts, management changes that were made included alteration of the ration and installation of a computer-operated feeder. After the initial visit, the herd was monitored for 30 months by the use of Dairy Herd Improvement monthly herd summary data. Several potential strengths and weaknesses of using selective production and reproduction monthly summary statistics were illustrated by this study. Milk production, as monitored by mature-equivalent production and average relative value-milk, continued to increase throughout the 30 months after intervention. Reproductive performance, as indicated by first-service conception rate, did not begin to improve until the final 6 months of the monitoring period. Overall, in addition to assisting in diagnostic efforts. Dairy Herd Improvement monthly herd summary data may be used to establish goals, provide comparisons, and maintain producer interest after practitioner intervention in herd management.  相似文献   

Epizootiological investigation of an outbreak of pullorum disease in an integrated broiler operation.     

D C Johnson  M David  S Goldsmith 《Avian diseases》1992,36(3):770-775

An integrated broiler company experienced a major outbreak of pullorum disease during 1990. The outbreak resulted in the distribution of Salmonella pullorum-infected birds to more than 150 roaster flocks in five states. Twenty-two parent (multiplier) breeder flocks became infected. An epizootiological investigation uncovered a grandparent male line breeder flock as the index flock supplying males to the affected parent flocks. Transmission apparently occurred vertically through the egg and horizontally by contact in the hatcheries and by placement of chicks on contaminated litter.  相似文献   

ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING A COMPOSITE COLLAGENOUS PROSTHESIS: A BIOMECHANICAL AND HISTOLOGIC STUDY IN RABBITS     

Dunn MG  Tria AJ  Kato YP  Bechler JR  Ochner RS  Zawadsky JP  Silver FH 《Veterinary surgery : VS》1993,22(1):56-56

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Mesenteric tear of the distal jejunum as a periparturient complication in a mare     

AJ DART  JR PASCOE 《Australian veterinary journal》1994,71(12):427-428

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EFFECT OF DEPENDENCY VERSUS NONDEPENDENCY ON LUNG LESION VISUALIZATION     

ROBERT D. PECHMAN  JR.  DVM 《Veterinary radiology & ultrasound》1987,28(5):185-190

Paraffin blocks and mineral oil were used as a model to determine the effect of dependency versus nondependency on radiographic visualization of lung lesions in lateral thoracic radiographs. It was concluded that the increased opacity of the material surrounding the lesion, not contact between the heart and the lesion, was responsible for the inability to detect lung disease in the dependent lung. The results were tested in dogs with pneumonia in the right middle lung lobe. When the dog was in right lateral recumbency, the dependent right lung was increased in opacity and decreased in volume and the pulmonary lesion was difficult to detect. When the dog was in left lateral recumbency, the nondependent right lung was increased in volume and decreased in opacity and the pulmonary disease was clearly visible. A single recumbent lateral radiograph must not be used to assess a dog with suspected lung disease because lesions in the dependent lung lobes may not be detected.  相似文献