Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Environ Monit Assess ; 192(4): 239, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32185492

RESUMO

In order to determine the stand age in the uneven-aged natural forest, a dynamic prediction model of stand volume and biomass was established in this study. In the model, the site quality grade was used as the dumb variable and the interval was used as the independent variable. In addition, the parameters of the model were estimated using immune evolutionary algorithm. The model was verified with the field data and the result revealed that the model had high accuracy. On this basis, the dynamic prediction model for forest stock was applied to evaluate the asset evaluation of uneven-aged natural forest and estimate carbon storage/sink potential of forest biomass. The selective logging period of the forest in the four plots was determined at the selective logging intensity of 40%. However, at the selective logging intensity of 40%, the forest ecological environment was suffered from the adverse effect to a certain extent from the perspective of scientific management, diversity of species, etc. Based on the comprehensive consideration of all the factors, it is recommended to set the selective cutting intensity in the range of 30 to 35%. The results can provide technical support for the application of selective logging income method in asset evaluation. Therefore, the results of this study have theoretical significance and practical application value in dynamic prediction of forest resources, asset evaluation and management, decision-making, etc.


Assuntos
Sequestro de Carbono , Monitoramento Ambiental , Florestas , Pinus , Biomassa , Pinus/crescimento & desenvolvimento , Árvores
2.
Poult Sci ; 103(8): 103913, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38914042

RESUMO

The H4 subtype of avian influenza virus (AIV) exhibits a wide host range and is commonly found in migratory waterfowl. Recent studies have revealed that the H4N6 AIV can infect guinea pigs via aerosol transmission without prior adaptation. Additionally, the Q226L/G228S substitutions in the receptor-binding site have led to structural changes in globular head of H4 AIV, resulting in a configuration similar to that of pandemic H2N2 and H3N2 human influenza viruses. This article provides an updated review of the historical evolution, global distribution, adaptive mutations, receptor-binding preferences, and host range of H4 AIV. The insights presented herein will help in assessing the potential risk of future H4 AIV epidemics.


Assuntos
Vírus da Influenza A , Influenza Aviária , Mutação , Animais , Influenza Aviária/virologia , Influenza Aviária/história , Vírus da Influenza A/genética , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/história , Especificidade de Hospedeiro , Aves , Evolução Molecular , Receptores Virais/metabolismo , Receptores Virais/genética
3.
Front Plant Sci ; 12: 692484, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34367215

RESUMO

Sapindus mukorossi Gaertn., an important oleaginous woody plant, has garnered increasing research attention owing to its potential as a source of renewable energy (biodiesel). Leaf structural traits are closely related to plant size, and they affect the fruit yield and oil quality. However, plant size factors that predominantly contribute to leaf structural traits remain unknown. Therefore, the purpose of this study was to understand the associations between leaf structural traits and plant size factors in even-aged stands of S. mukorossi. Results showed that leaf length (LL) and leaf area (LA) markedly increased with the increasing diameter at breast height (DBH) and tree height (TH), although other leaf structural traits did not show noticeable changes. Difference in slopes also indicated that the degree of effect of plant size factors on leaf structural traits was in the order of TH > DBH. Leaf structural traits showed no systematic variation with crown width (CW). LA was significantly positively correlated with LL, leaf width (LW), LL/LW, and leaf thickness (LT) and was significantly but negatively correlated with leaf tissue density (LTD) and leaf dry mass content (LDMC). Specific leaf area showed a significantly negative correlation with LT, LDMC, and LTD. LTD showed a significantly positive correlation with LDMC, but a negative correlation with LT. The results were critical to understand the variability of leaf structural traits with plant size, can provide a theoretical foundation for further study in the relationship between leaf structural traits and fruit yield, and regulate leaf traits through artificial management measures to promote plant growth and fruit yield.

4.
China CDC Wkly ; 3(20): 430-433, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34594906

RESUMO

What is already known about this topic? Brucellosis is one of the most important zoonotic diseases in China. Goat milk and dairy products are essential pathways for foodborne transmission of brucellosis. Pasteurization can completely kill Brucellaspp. in milk, and milk-borne transmission is mainly related to unhealthy dietary hygiene habits and insufficient epidemic control among animals. What is added by this report? This epidemic is the first outbreak of brucellosis in Zhangping City, Fujian Province. A total of 6 confirmed cases were found, and the onset time was from April to June 2019. The investigation suggested that the transmission chain of the epidemic included a private butcher, an infected goat from the north, a dairy farmer, close contact spread, unsterilized goat milk, and consumers drinking raw goat milk. What are the implications for public health practices? For the non-endemic area of brucellosis, preventing the import of infected animals and enhancing the practitioner's and the public's awareness of disease prevention has important public health significance. It is necessary to strengthen the transregional quarantine of livestock, the food safety inspection and management, and the practitioners' and public's awareness of food safety.

5.
Micron ; 124: 102709, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31280005

RESUMO

The degradation of optical microscopic imaging is space-variant, and how to fast restore optical degraded image remains a special problem. Based on point spread function (PSF) estimation under each field of view (FOV), a L0 gradient-constrained image restoration method is proposed to solve optical degradation in microscopic imaging. Firstly, the whole scene is segmented into several different regions according to different FOV. The PSFs for each region are estimated from modulation transfer function (MTF) measured in advance. Secondly, a penalty function is designed using L0 gradient constraint to deblur the degraded images of each sub-FOV. Finally, a weighted stitching approach is used to stitch the restored images of multiple FOV (m-FOV). Experimental results indicate that the m-FOV analysis could well solve the problem of space-variant degradation. Compared with the other methods, both subjective and objective evaluation results prove that the L0 norm idea could rapidly and effectively restore the degraded image. The approach could be well applied to a real product.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA