Landscape patterns from mathematical morphology on maps with contagion

The perceived realism of simulated maps with contagion (spatial autocorrelation) has led to their use for comparing landscape pattern metrics and as habitat maps for modeling organism movement across landscapes. The objective of this study was to conduct a neutral model analysis of pattern metrics defined by morphological spatial pattern analysis (MSPA) on maps with contagion, with comparisons to phase transitions (abrupt changes) of patterns on simple random maps. Using MSPA, each focal class pixel on a neutral map was assigned to one of six pattern classes—core, edge, perforated, connector, branch, or islet—depending on MSPA rules for connectivity and edge width. As the density of the focal class (P) was increased on simple random maps, the proportions of pixels in different pattern classes exhibited two types of phase transitions at threshold densities (0.41 ≤ P ≤ 0.99) that were predicted by percolation theory after taking into account the MSPA rules for connectivity and edge width. While there was no evidence of phase transitions on maps with contagion, the general trends of pattern metrics in relation to P were similar to simple random maps. Using an index P for comparisons, the effect of increasing contagion was opposite that of increasing edge width.     

Persistent infections after natural transmission of bovine viral diarrhoea virus from cattle to goats and among goats

Bovine viral diarrhoea virus (BVDV) is an economically important pathogen of cattle worldwide. Infection of a pregnant animal may lead to persistent infection of the foetus and birth of a persistently infected (PI) calf that sheds the virus throughout its life. However, BVD viruses are not strictly species specific. BVDV has been isolated from many domesticated and wild ruminants. This is of practical importance as virus reservoirs in non-bovine hosts may hamper BVDV control in cattle. A goat given as a social companion to a BVDV PI calf gave birth to a PI goat kid. In order to test if goat to goat infections were possible, seronegative pregnant goats were exposed to the PI goat. In parallel, seronegative pregnant goats were kept together with the PI calf. Only the goat to goat transmission resulted in the birth of a next generation of BVDV PI kids whereas all goats kept together with the PI calf aborted. To our knowledge, this is the first report which shows that a PI goat cannot only transmit BVD virus to other goats but that such transmission may indeed lead to the birth of a second generation of PI goats. Genetic analyses indicated that establishment in the new host species may be associated with step-wise adaptations in the viral genome. Thus, goats have the potential to be a reservoir for BVDV. However, the PI goats showed growth retardation and anaemia and their survival under natural conditions remains questionable.     

Impact of scale on morphological spatial pattern of forest

Assessing and monitoring landscape pattern structure from multi-scale land-cover maps can utilize morphological spatial pattern analysis (MSPA), only if various influences of scale are known and taken into account. This paper lays part of the foundation for applying MSPA analysis in landscape monitoring by quantifying scale effects on six classes of spatial patterns called: core, edge, perforation, branch, connector and islet. Four forest maps were selected with different forest composition and configuration. The sensitivity of MSPA to scale was studied by comparing frequencies of pattern classes in total forest area for various combinations of pixel size (P) and size parameter (S). It was found that the quantification of forest pattern with MSPA is sensitive to scale. Differences in initial composition and configuration influence the amount but not the general tendencies of the variations of morphological spatial pattern (MSP) class proportions with scale. Increase of P led to data generalization resulting in either a removal of the small size features or their potential transformation into other non-core MSP classes, while an increase of S decreases the MSP core area and this process may transform small core areas into the MSP class islet. We established that the behavior of the MSPA classes with changing scale can be categorized as consistent and robust scaling relations in the forms of linear, power, or logarithmic functions over a range of scales.     

Metabolic blood profile of beef heifers during oestrous and non‐oestrous states

Haematological metabolic profiles in heifers could contribute to the development of proxies for oestrous detection and provide clues to further characterize biological changes during oestrus. One hundred and seven beef heifers were observed for oestrous behaviour twice daily for 124 days. Feed intake and productive performance (body weight and composition) traits were measured, and feed efficiency was determined using residual feed intake (kg DM/day). Blood plasma samples were collected when signs of oestrus were observed and every 30 ± 2 days. Heifers were considered in oestrus (n = 71) when plasma progesterone concentrations were <0.6 ng/ml. Least square means of blood metabolic parameters were compared between oestrous and non‐oestrous states and within oestrous groups according to performance traits and age. Heifers in oestrus exhibited higher concentrations of alkaline phosphatase, aspartate aminotransferase (AST), beta‐hydroxybutyric acid, creatine kinase (CK) and triiodothyronine (T3) than heifers in non‐oestrus. Heifers in oestrus revealed lower osmolality and concentrations of calcium, sodium and total protein than during non‐oestrus. Younger (and smaller) heifers had greater concentrations of CK, gamma‐glutamyl transferase (GGT), glucose and sodium than the older heifers. Heifers with lower fatness had increased osmolality and concentrations of cholesterol, CK, phosphorus, sodium and reduced T3 levels. Feed efficient heifers had greater levels of AST, cholesterol and GGT than inefficient heifers. Blood plasma parameters may be complementary to oestrous detection upon further validation; effects of age, feed efficiency, body size and body composition should be considered to optimize this haematological assessment.     

Acute Copper Toxicity and Acclimation to Copper Using the Behavioral Endpoint of Shoaling,in the Least Killifish (Heterandria formosa)

Water, Air, &; Soil Pollution - The release of heavy oil from laboratory-contaminated sediments was studied in a series of kinetic and equilibrium experiments. The kinetic curves could be...     

Scrotal circumference adjustment factors for age and weight differences in beef bulls

Scrotal circumference measurements were analyzed to develop appropriate adjustment factors for age and body weight differences in beef bulls. Age, body weight, and scrotal circumference measurements were collected on 863 Angus, 753 Polled Hereford, and 302 Simmental bulls from the Missouri tested bull sale, 1169 Polled Hereford bulls from the American Polled Hereford Association, and 465 Polled Hereford and 264 Simmental bulls from Nichols Farms in Bridgewater, Iowa. Within sources, data were subdivided into appropriate subsets and then each subset was statistically analyzed. Adjustment factors to remove differences in scrotal circumference due to age and body weight were developed for bulls of each of the 3 breeds studied.     

ANGIOGRAPHIC APPEARANCE OF COMMON CAROTID COLLATERAL CIRCULATION IN THE GOAT RESULTING FROM PROSTHETIC GRAFT IMPLANTATION

Carotid arteriography was performed in six normal goats. The same procedure was performed on these six and 112 other goats at various time intervals after placement of an arterial graft in one or both carotid arteries. An arterial catheter was introduced into the femoral artery and advanced to the origin of the brachiocephalic trunk with the aid of image-intensified fluoroscopy. Hand-injection of the contrast medium resulted in complete opacification of both common carotid arteries in normal animals. Opacification of one or both of the vertebral arteries was usually seen in the goats with prosthetic grafts. The left vertebral artery was seen more often than the right, and when both vertebral arteries were seen together, the left was often larger. This angiographic method proved to be reliable for opacifying both common carotid arteries from their origin on the brachiocephalic trunk to the cranial cervical region. No clinical problems were associated with either the catheterization procedure or with the permanent ligation of the catheterized femoral artery.     

Infestation in the dog by the paralysis tick, Ixodes holocyclus — 4. Cardiovascular effects

To determine the extent and significance of changes in heart rate and rhythm noticed previously in dogs paralysed with Ixodes holocyclus, two studies were undertaken. In one the electrocardiogram was recorded at stages throughout the disease and the traces analysed for changes, while in the second a detailed study of the effect of Ixodes holocyclus on the cardiovascular system was undertaken. The electrocardiographic changes were extremely variable between stages and between dogs. Generally, if a dysrhythmia occurred in stages 1, 2 or 3 it tended to be sinus tachycardia, ventricular tachycardia or sinus arrest. In stage 4 sinus arrest, sinus bradycardia, or sinus or ventricular tachycardia were the prominent dysrhythmias, whereas in stage 5 sinus bradycardia predominated. Cardiovascular measurements indicated an increase in peripheral vascular resistance leading to a significant elevation in mean arterial pressure at all stages of the disease. Cardiac output was decreased significantly only at stage 2, although it was below the control measurements at all stages. Pulmonary arterial pressure was significantly elevated at stages 2, 3 and 4 due most probably to an increase in pulmonary vascular resistance. Myocardial contractility was not significantly changed throughout the disease. The changes observed in the electrocardiogram and the cardiovascular system in stages 1, 2 and 3 are unlikely to be due to hypoxia and could represent dysfunction of the autonomic nervous system. During stages 4 and 5 oxygen levels were below normal and the bradycardia seen terminally is almost certainly due to hypoxaemia.(ABSTRACT TRUNCATED AT 250 WORDS)