Effects of land use management on biotic integrity: An investigation of bird communities

We examined the response of bird communities to a gradient of human impact in the Adirondack Park of northern New York State by testing the relationship of land use management types to an Index of Biotic Integrity (IBI) across the Adirondack landscape. We created the IBI by placing birds into 12 different guild categories and scoring study blocks according to relative representation of specialist versus generalist guild types. We investigated three questions relating to the effects of land use management on biotic integrity in the Adirondacks: (1) are there differences in biological integrity among the major land use types; (2) if so, what characteristics of these land use types are associated with high integrity bird communities; and, (3) to what degree is land management regulation effective in maintaining biological integrity in the Adirondack Park? We found significant differences in total, functional, compositional, and structural integrity on five land use types ranging from hamlet to wilderness. In all cases, integrity was lowest in hamlet areas and increased along the gradient to its highest level in wilderness areas.Biotic integrity showed strong groupings of the five land use classes. We found that bird community integrity was strongly related to roadlessness and that birds primarily responded to the distinction between developed and undeveloped land types. In contrast to roads and human development, forest management impacts in the Adirondacks do not appear to be of a high enough intensity to have significant negative impacts on breeding bird community integrity. Clustering of development is a means by which integrity may be safeguarded for the long term in the Adirondack Park.     

Effect of human treading on enchytraeid fauna of hornbeam-oak forests in Hungary

Summary The effect of human treading on the composition of the enchytraeid fauna was studied on hiking trails in hornbeam-oak forests in Hungary. Compaction of the soil due to continuous treading has an unfavourable influence on the enchytraeid fauna, with density and species richness decreasing significantly. However, an interesting result is that one species, Fridericia conculcata, prefers these heavily trodden areas.Dedicated to the late Prof. Dr. M.S. Ghilarov     

Road Density and Landscape Pattern in Relation to Housing Density,and Ownership,Land Cover,and Soils

Roads are conspicuous components of landscapes and play a substantial role in defining landscape pattern. Previous studies have demonstrated the link between roads and their effects on ecological processes and landscape patterns. Less understood is the placement of roads, and hence the patterns imposed by roads on the landscape in relation to factors describing land use, land cover, and environmental heterogeneity. Our hypothesis was that variation in road density and landscape patterns created by roads can be explained in relation to variables describing land use, land cover, and environmental factors. We examined both road density and landscape patterns created by roads in relation to suitability of soil substrate as road subgrade, land cover, lake area and perimeter, land ownership, and housing density across 19 predominantly forested counties in northern Wisconsin, USA. Generalized least squares regression models showed that housing density and soils with excellent suitability for road subgrade were positively related to road density while wetland area was negatively related. These relationships were consistent across models for different road types. Landscape indices showed greater fragmentation by roads in areas with higher housing density, and agriculture, grassland, and coniferous forest area, but less fragmentation with higher deciduous forest, mixed forest, wetland, and lake area. These relationships provide insight into the complex relationships among social, institutional, and environmental factors that influence where roads occur on the landscape. Our results are important for understanding the impacts of roads on ecosystems and planning for their protection in the face of continued development.     

A Seroprevalence Study of Camel Brucellosis in Three Camel-rearing Regions of Ethiopia

A cross-sectional investigation was made into the seroprevalence of brucellosis in camels in three arid and semi-arid camel-rearing regions of Ethiopia (Afar, Somali and Borena) between November 2000 and April 2001. When sera collected from 1442 accessible camels were screened with the Rose Bengal plate test (RBPT), 82 (5.7%) of them reacted. The results of a complement fixation test (CFT) on those sera that had given a positive reaction to the screening test then indicated a 4.2% prevalence of brucellosis in the tested camels. There was a significant difference in the prevalence of brucellosis (² = 7.91, p<0.05), which was highest in Afar (5.2%) followed by Somali (2.8%) and Borena (1.2%) regions. Camels in Afar had a four times higher risk of brucellosis with an odds ratio (OR) of 4.34 (confidence interval, CI = 1.76–10.72, p<0.001) compared to the risk in Borena. Likewise, Afar had higher risk (OR = 1.76, 1.13–2.74, p<0.05) than that in Somali. There was no significant difference in seroprevalence between the sexes (p>0.05). Although a higher prevalence (6.3%) was observed in camels over 3 years old in Afar, there was no significant overall age difference (p>0.05).     

How to substantiate eradication of bovine brucellosis when aspecific serological reactions occur in the course of brucellosis testing

Collaborative work was financed by the EU to develop and assess new diagnostic tools that can differentiate between bovine brucellosis and bovine infections due to Yersinia enterocolitica O:9 either in conjunction with, or as an alternative to, the classical serological, bacteriological or allergic skin tests. Sixteen heifers were experimentally infected with Brucella abortus biovar 1 (five heifers), Brucella suis biovar 2 (two heifers), Y. enterocolitica O:9 (six heifers) and Y. enterocolitica O:3 (three heifers). Four heifers, naturally infected with Y. enterocolitica O:9 that presented aspecific brucellosis serological reactions were also included in the experiment. A self-limited infection was induced in cattle by B. suis biovar 2. All the brucellosis serological tests used, i.e. the slow agglutination test (SAW), the Rose Bengal test (RB), the complement fixation test (CFT), indirect and competitive ELISA’s, lacked specificity when used to analyze sera from Y. enterocolitica O:9 infected animals. A Yersinia outer membrane proteins (YOPs)-ELISA was also used and although the test is able to detect a Yersinia group infection, it provided no evidence of whether or not there is a possible brucellosis infection when dual infections are present. The brucellergen IFN-γ test showed a lack of specificity also. The only test that was proven to be specific is the brucellergen skin test. All brucellosis serological tests, except the indirect ELISA, were limited in their ability to detect B. abortus persistently infected animals.

Based on these experimental studies, a strategy was implemented as part of the year 2001 Belgian Brucellosis Eradication Program to substantiate the eradication of bovine brucellosis. Epidemiological inquiries have identified risk factors associated with aspecific serological reactions, possible transmission and infection of cattle by B. suis biovar 2 from infected wild boars; and both legal and administrative measures taken by the veterinary services. No cases of bovine brucellosis have been confirmed in Belgium since March 2000.     

Effect of Vaccination with Brucella abortus Strain RB51 on Heifers and Pregnant Cattle

Thirteen cows, which had been vaccinated as calves with strain 19, were revaccinated twice or three times as adults with 1×10⁹ cfu of B. abortus strain RB51. Their serological responses following adult vaccination remained negative to conventional brucellosis surveillance tests. Vaccination with strain RB51 during the eighth month of pregnancy did not induce abortion, although strain RB51 was recovered from milk for up to 69 days after vaccination. In a parallel study, thirteen 8- to 10-month-old heifers were vaccinated as calves with 10⁹ cfu of strain RB51. The heifers remained seronegative to conventional brucellosis surveillance tests but antibody responses to RB51 could be demonstrated using an indirect ELISA. This study showed that multiple vaccination with strain RB51 did not induce seroconversion to brucellosis surveillance tests. In addition, this study suggests that 10⁹ cfu of strain RB51 is safe for use in pregnant cattle.     

抗癌基因p 53 导入番茄的初步研究

 通过根癌农杆菌( Agrobacterium tumefaciens) 介导, 利用特异表达的phaseolin 基因的启动子与人类野生型抗癌基因p 53 构建嵌合基因, 对&#1048578; 美味樱桃 番茄进行遗传转化, 获得转化番茄再生植株。通过组织化学法、PCR 扩增及Southern 杂交检测, 证明人类野生型p 53基因已整合到转基因番茄植株的基因组。     

茶薪菇培养物中粗三萜含量测定及抗氧化抗肿瘤活性研究

采用石油醚、乙酸乙酯和乙醇分别对液体培养的茶薪菇菌丝体和培养液进行抽提或萃取。分析表明,石油醚、乙酸乙酯和乙醇提取物中均含有三萜类物质,并具有较高的抗氧化活性和抑制人胃癌细胞株BGC-823增殖的作用。     

CCL3 promotes hBMSC proliferation and inhibits exosome secretion

AIM: To explore the regulatory effect of chemokine CCL3 on exosome secretion from human bone marrow mesenchymal stem cells (hBMSCs).METHODS: hBMSCs were stimulated with chemokine CCL3 at different concentrations in vitro. The proliferation of hBMSCs was measured by CCK-8 assay and viable cell counting. Exosome secretion from hBMSCs was qualitatively analyzed by transmission electron microscope (TEM) and flow cytometry, and the quantitative analysis was carried out by flow cytometry and nanoparticle tracking analysis (NTA).RESULTS: Compared with control group, the viability of the hBMSCs detected by CCK-8 assay was increased when hBMSCs were treated with CCL3 (P<0.05). The results of viable cell counting demonstrated that the number of hBMSCs was raised in CCL3 group in a dose-dependent manner (P<0.05). The results of flow cytometry showed that hBMSCs expressed 3 CCL3-related specific receptors, CCR1, CCR5 and CCR9. Compared with control group, the fluorescence intensity of CCR9 in CCL3 group was obviously enhanced. However, no significant difference of fluorescence intensity for CCR5 and CCR1 was observed between the 2 groups. The results of NTA demonstrated that the secretion capacity of CCL3-induced hBMSCs was far less than that in control group (P<0.05). However, the microvesicles larger than 100 nm in CCL3 groups were increased (P<0.05). The above results indicated that the higher concentration of CCL3 induced the lower secretion of exosomes. In addition, the results of flow cytometry demonstrated that CCL3-induced hBMSCs showed lower quantity of CD9⁺ exosomes than those in control group (P<0.01).CONCLUSION: CCL3 promotes the proliferation of hBMSCs but depresses the secretion of exosomes in a dose-dependent manner. CCL3 affects the size distribution of exosomes and increases the number of nonfunctional microvesicles of larger than 100 nm in size. CCL3 induces the expression of CCR9 in hBMSCs.     

Antagonistic effect of thalidomide on TGF-β1-induced change of CTGF gene promoter-binding proteins in HELF cells

AIM:To investigate the antagonistic effect of thalidomide (THD) on the activation of connective tissue growth factor (CTGF) gene promoter induced by transforming growth factor-β₁ (TGF-β₁) in human embryonic lung fibroblasts (HELF). METHODS:Luciferase reporter vector driven by CTGF gene promoter was used to detect the effects of TGF-β₁ and THD on the activity of CTGF gene promoter, and DNA pull-down assay with CTGF gene promoter as a probe was used to analyze the changes of CTGF promoter-binding proteins under different conditions. RESULTS:TGF-β₁ increased the activity of reporter driven by CTGF gene promoter (P<0.01), while THD significantly inhibited TGF-β₁-induced increase in the reporter activity dose-dependently (P<0.01). At the same time, THD had inhibitory effect on the TGF-β₁-induced change of CTGF gene promoter-binding proteins (P<0.05). CONCLUSION:Regulation of CTGF gene promoter-binding proteins takes part in TGF-β₁-induced activation of CTGF gene promoter, while THD has antagonistic effect on this process.