Biomedical subjects

Gao Chen

Publications and source records attributed to Gao Chen.

23 records · Page 2Linked to original sources

PubMed2003

[Approaches for assessing forest ecosystem health].

Assessment and indicator system become the key issues in the research on ecosystem health in 21st century. Assessing forest ecosystem health gradually attach much attention because it is an important component of terrestrial ecosystem. The definition, measurement, evaluation and its management had been discussed broadly, and some theories, assessing methods and frameworks had been proposed, which provides a new concept and a serial research approaches for dealing with the crisis of terrestrial ecosystems, even the environment problems in the world. Now, the common operational models for assessing forest ecosystem health do not exist owing to the manifold limitations. This paper discussed forest ecosystem health problem, and brought forward three preconditions for assessing forest ecosystem health: 1) a clear conceptual framework; 2) adequate data sets; 3) proper research and analysis techniques. The issues of three preconditions were discussed, and the possible approaches for the assessing research on forest ecosystem health, e.g., long-term studies and environment monitoring, space-for-time substation studies, e.g., history approaches, economics valuation and others were expariated.

Ecosystem↗

PubMed2002

Activation of the Rb/E2F1 pathway by the nonproliferative p38 MAPK during Fas (APO1/CD95)-mediated neuronal apoptosis.

Aberrant activation of the Rb/E2F1 pathway in cycling cells, in response to mitogenic or nonmitogenic stress signals, leads to apoptosis through hyperphosphorylation of Rb. To test whether in postmitotic neurons the Rb/E2F1 pathway can be activated by the nonmitogenic stress signaling, we examined the role of the p38 stress-activated protein kinase (SAPK) in regulating Rb phosphorylation in response to Fas (CD95/APO1)-mediated apoptosis of cultured cerebellar granule neurons (CGNs). Anti-Fas antibody induced a dramatic and early activation of p38. Activated p38 was correlated with the induction of hyperphosphorylation of both endogenous and exogenous Rb. The p38-selective inhibitor, SB203580, attenuated such an increase in pRb phosphorylation and significantly protected CGNs from Fas-induced apoptosis. The cyclin-dependent kinase-mediated Rb phosphorylation played a lesser role in this neuronal death paradigm, since cyclin-dependent kinase inhibitors, such as olomoucine, roscovitine, and flavopiridol, did not significantly prevent anti-Fas antibody-evoked neuronal apoptosis. Hyperphosphorylation of Rb by p38 SAPK resulted in the release of Rb-bound E2F1. Increased E2F1 modulated neuronal apoptosis, since E2F1-/- CGNs were significantly less susceptible to Fas-mediated apoptosis in comparison with the wild-type CGNs. Taken together, these studies demonstrate that neuronal Rb/E2F1 is modulated by the nonproliferative p38 SAPK in Fas-mediated neuronal apoptosis.

Animals↗

PubMed2002

[On forest ecosystem health and its evaluation].

Definition and connotation of forest ecosystem health were introduced, and existing ideas and methods of health evaluation were analyzed in this paper. Furthermore, forest ecosystem health was discussed from the aspects of the management objective approach, ecosystem approach, and integration approach. Widespread application of ecological indicators is the main means of evaluation on forest ecosystem health at present, and some material forest health evaluation methods, especially EMAP and FHM, were introduced and summarized to impel the relative researches in China.

Ecosystem↗

PubMed2002

[Minimum sampling area and species richness of riparian community in erdaobaihe forested watershed].

Riparian zone is an important component of small forested watershed. Due to the integrate effects of stream water and edge effect, there are obvious difference in composition, structure, and distribution pattern between riparian community and non-riparian community. Community minimum sampling areas are also different. In this study, minimum sampling areas of riparian community in original broad-leaved and Korean pine forest in Changbai Mountain were studied by using species-area curve. At the same time, species richness of riparian community was discussed. The results showed that the minimum sampling areas of riparian plant community were smaller than those of the non-riparian community. According to the original broad-leaved and Korean pine forest in Changbai Mountain, the average community minimum sampling areas in riparian zone of three plots including 60%, 80%, and 90% of community species were about 80 m2, 180 m2, and 320 m2, respectively. And then, those of forest community were about 260 m2, 380 m2, and 480 m2 correspondingly. The results also showed that the species richness of riparian community was higher than that of non-riparian community.

Ecosystem↗

PubMed2002

[Advances in research on ecological land classification].

Land classification is the base of land evaluation, land planning and land management, and plays an important role in the sustainable development of forestry resource. Ecological land classification (ELC) is the main approuch and direction of land classification. Along with the development of landscape ecology and 3S techniques, developing of ecological classification system (ECS) becomes the keystone of ELC. The definition, history, basic characteristics of ELC, the theory of ECS and its' prospects were systematically reviewed in this paper. The prospects were also described for the development of ECS methodology and the application of ELC. The general direction of ecological land research, which was a multi-factors and multi-levels syntheses based on the multi-objects administration of resource (forest, land and waters), was the combination of quantificational and qualitative research. It is necessary to carry out relevant researches in China.

China↗