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101.
Impact of scale on morphological spatial pattern of forest 总被引:1,自引:1,他引:0
Katarzyna Ostapowicz Peter Vogt Kurt H. Riitters Jacek Kozak Christine Estreguil 《Landscape Ecology》2008,23(9):1107-1117
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. 相似文献
102.
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... 相似文献
103.
T A Gipson D W Vogt J W Massey M R Ellersieck 《Journal of the American Veterinary Medical Association》1985,186(6):580-582
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. 相似文献
104.
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.
相似文献
C. Estreguil |
105.
The widely outcropping igneous and metamorphic rocks of the circum-Baikal region all contain illite and chlorite resulting from early alteration of primary minerals. These rocks were deeply weathered and leached, mainly to kaolinite, under the warm and mostly wet Upper-Cretaceous and Palaeogene climates. During the following severely dry and cold Pleistocene episodes, the glacier cover was restricted, allowing the formation of permafrost, which is still several hundred metres thick in the northern Baikal region, while the lowlands of the central and southern regions belong to the so-called “sporadic permafrost area”. The lack of glacial abrasion during the cryo-arid climate preserved somehow the weathering products of the previous warm periods that presently crop out next to the relics of the periglacial Pleistocene weathering. These relict deposits derived from the same substrate rocks as those weathered during the warm and wet climate, but they differ in the clay composition with the occurrence of a montmorillonite-type smectite that is dominant in some sites. 相似文献
106.
107.
108.
Obeidat BS Strickland JR Vogt ML Taylor JB Krehbiel CR Remmenga MD Clayshulte-Ashley AK Whittet KM Hallford DM Hernandez JA 《Journal of animal science》2005,83(2):466-477
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. 相似文献
109.
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. 相似文献
110.
Martin-Jurado O Vogt R Kutter AP Bettschart-Wolfensberger R Hatt JM 《American journal of veterinary research》2008,69(10):1254-1261
OBJECTIVE: To determine the effect of inhalation of isoflurane at end-tidal concentrations greater than, equal to, and less than the minimum anesthetic concentration (MAC) on bispectral index (BIS) in chickens. Animals-10 chickens. PROCEDURES: For each chicken, the individual MAC of isoflurane was determined by use of the toe-pinch method. After a 1-week interval, chickens were anesthetized with isoflurane at concentrations 1.75, 1.50, 1.25, 1.00, and 0.75 times their individual MAC (administered from higher to lower concentrations). At each MAC multiple, a toe pinch was performed and BIS was assessed and correlated with heart rate, blood pressure, and an awareness score (derived by use of a visual analogue scale). RESULTS: Among the chickens, mean +/- SD MAC of isoflurane was 1.15 +/- 0.20%. Burst suppression was detected at every MAC multiple. The BIS and awareness score were correlated directly with each other and changed inversely with increasing isoflurane concentration. Median (range) BIS values during anesthesia at 1.75, 1.50, 1.25, 1.00, and 0.75 MAC of isoflurane were 25 (15 to 35), 35 (25 to 45), 35 (20 to 50), 40 (25 to 55), and 50 (35 to 65), respectively. Median BIS value at extubation was 70 +/- 9. Values of BIS correlated with blood pressure, but not with heart rate. Blood pressure changed with end-tidal isoflurane concentrations, whereas heart rate did not. CONCLUSIONS AND CLINICAL RELEVANCE: Assessment of BIS can be used to monitor the electrical activity of the brain and the degree of unconsciousness in chickens during isoflurane anesthesia. 相似文献