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.     

Forest cover and pattern changes in the Carpathians over the last decades

This study aims at developing a satellite-based methodology for the implementation of two Ministerial Conference on the Protection of Forests in Europe indicators for the European Alpine Bio-geographic region, and their changes over time: (1) area of forest cover and (2) forest spatial pattern. The northern Carpathians were selected as a study area due to the documented recent increase of forest cover. Changes of forest cover were quantified using Landsat images for the years 1987 and 2000. Single-date forest–non-forest maps were derived by image segmentation and supervised classification, including the use of ancillary data (CORINE Land Cover and a digital elevation model). These maps were an input for the post-classification change detection. The forest spatial pattern maps with four classes (core, patch, edge and perforated forest) were derived with morphological image processing. A simple method to mask uncertainty areas on forest maps and related products was also developed. The accuracy of the resulting forest–non-forest map was assessed with orthophotos and amounts to 93.9%. Uncertainty areas, for which change assessment was judged more difficult and less reliable, were not considered for assessing forest cover change. The annual forest cover change rate of 0.38% was found over the 1987–2000 period. For the 13-year time period, we found a decrease of core forest and an increase of patch and perforated forest. We conclude that the proposed methodology allows to quantify changes of forest cover and forest spatial pattern at ∼1 ha minimum mapping unit.

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.     

Carbon stock assessment and soil carbon management in agricultural land‐uses in Thailand

The organic carbon pool in agricultural land‐uses is capable of enhancing agricultural sustainability and serving as a potential sink of atmospheric carbon dioxide. A study was carried out to estimate and map carbon stock of different agricultural land‐uses in a sub‐watershed of Thailand and to assess the land‐use sustainability with respect to carbon management. A quadrat sampling methodology was adopted to estimate the biomass and its carbon content of 11 different land‐uses in the study area. Existing soil data were used to calculate the soil carbon. GIS was used for integrating biomass carbon, soil carbon and carbon stock mapping. Roth carbon model was used to project the soil carbon of present land‐uses in the coming 10 years and based on which the sustainability of land‐uses was predicted. The total carbon stock of agricultural land‐uses was estimated to be 20·5 Tg, of which 41·49 per cent was biomass carbon and 58·51 per cent was soil carbon. Among the land‐uses, para rubber had the highest average biomass C (136·34 Mg C ha⁻¹) while paddy had the lowest (7·08 Mg C ha⁻¹). About four‐fifths of agricultural land‐uses in the watershed are sustainable in maintaining the desired level of soil carbon in coming 10 years while one‐fifths are unstable. Such information on carbon stock could be valuable to develop viable land‐use options for agricultural sustainability and carbon sequestration. Copyright © 2007 John Wiley & Sons, Ltd.     

Effects of locoweed on serum swainsonine and selected serum constituents in sheep during acute and subacute oral/intraruminal exposure

A study was conducted to evaluate the effects of acute and subacute locoweed exposure on serum swainsonine concentrations and selected serum constituents in sheep. Thirteen mixed-breed wethers (BW = 47.5 +/- 9.3 kg) were assigned randomly to 0.2, 0.4, or 0.8 mg of swainsonine x kg BW(-1) x d(-1) treatments. During acute (24 h) and subacute (19 d) exposure, serum swainsonine was detected in all treatments and was greatest (P < 0.03) in the 0.8 mg treatment. Serum alkaline phosphate (ALK-P) activity was increased (P < 0.01) for the 0.8 mg treatment compared with baseline (0 h) by 7 h and continued to increase throughout the initial 22 h following acute exposure to locoweed. A linear increase (P < 0.01) in serum ALK-P activity was noted, with the rate being 3.00 +/- 0.56 U x L(-1) x h(-1). Serum ALK-P activity was increased (P < 0.05) across treatments on d 7 over d -19, -12, 0, 1, 21, and 26; on d 14 over d -19, -12, 0, and 26; and on d 19 over d -19, -12, 0, 1, 21, and 26. By d 20, approximately 48 h after last exposure to swainsonine, serum ALK-P activities were no longer different (P = 0.13) than baseline (d -19, -12, and 0), and by d 26 values had generally returned to baseline. No linear (P = 0.98), quadratic (P = 0.63), or cubic effects of swainsonine with time from exposure were noted for serum aspartate aminotransferase. Similar to serum ALK-P activities, serum aspartate aminotransferase activities were increased (P < 0.05) across treatment levels on d 7, 14, 19, 20, 21, and 26 over those on d -19, -12, 0, and 1. Total serum Fe was decreased (P < 0.05) within the initial 22 h following the swainsonine exposure. On d 21 (48 h after swainsonine feeding ended), serum Fe increased to 472 mg/L. Concentrations of ceruloplasmin were lower (P < 0.10) on d 14 and 19 following exposure to locoweed. Recovery of ceruloplasmin levels coincided with similar changes in serum Fe. There was a linear (slope = 0.33 mg x dL(-1) x d(-1); P < 0.01) effect with time of exposure to locoweed (i.e., swainsonine) on serum triglyceride concentrations. Rapid changes in serum ALK-P and Fe concentrations without parallel changes in other damage markers indicate that acute exposure to swainsonine induces metabolic changes that may impair animal production and health before events of cytotoxicity thought to induce clinical manifestation of locoism.     

Search for physical interaction between BICP0 of bovine herpesvirus-1 and p53 tumor suppressor protein

The immediate-early (IE) protein BICP0 of bovine herpesvirus-1 (BHV-1) may have other functions besides transactivation of viral promoters. Recently, we observed that BICP0, delivered to cultured cells by a helpervirus-free amplicon system, forms spherical or doughnut-like structures in which the tumor suppressor protein p53 is sequestered. The objective was to determine whether BICP0 and p53 interact physically, we used both yeast and mammalian two-hybrid systems. As a bait plasmid, pVA3 which encodes a hybrid protein consisting of the Gal4 DNA binding domain fused to murine p53 was used. The BICP0 gene or its truncated versions were inserted into the prey plasmid pGAD424. Bait and prey plasmids were cotransformed into yeast strain Y153, which has LacZ and HIS3 reporter genes under the control of Gal4 upstream activating sequence. After 4-6 days, colonies were stained for beta-galactosidase activity. In the mammalian two-hybrid system, pM-53 was used as a bait where truncated p53 fused to Gal4 DNA binding domain is expressed. The BICP0 gene was cloned into prey plasmid pVP16. The interaction between p53 and SV40 T-antigen was evaluated as a positive control in both systems. Neither full-length BICP0 nor its truncated derivatives induced beta-galactosidase activity in yeast whereas the positive control turned blue under the same conditions. The mammalian two-hybrid system, in which chloramphenicol acetyltransferase (CAT) activity was used as a reporter, also failed to show an interaction between these two proteins. Co-localization of p53 with BICP0 in spherical structures is unlikely to result from a direct physical interaction between these two proteins. Mediation by additional cellular proteins may be required.