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21.
Environmental controls over carbon exchange of three forest ecosystems in eastern China 总被引:1,自引:0,他引:1
GUI‐RUI YU LEI‐MING ZHANG XIAO‐MIN SUN YU‐LING FU XUE‐FA WEN QIU‐FENG WANG SHENG‐GONG LI CHUAN‐YOU REN XIA SONG YUN‐FEN LIU SHI‐JIE HAN JUN‐HUA YAN 《Global Change Biology》2008,14(11):2555-2571
Net ecosystem productivity (NEP) was continuously measured using the eddy covariance (EC) technique from 2003 to 2005 at three forest sites of ChinaFLUX. The forests include Changbaishan temperate mixed forest (CBS), Qianyanzhou subtropical coniferous plantation (QYZ), and Dinghushan subtropical evergreen broad‐leaved forest (DHS). They span wide ranges of temperature and precipitation and are influenced by the eastern Asian monsoon climate to varying extent. In this study, we estimated ecosystem respiration (RE) and gross ecosystem productivity (GEP). Comparison of ecosystem carbon exchange among the three forests shows that RE was mainly determined by temperature, with the forest at CBS exhibiting the highest temperature sensitivity among the three ecosystems. The RE was highly dependent on GEP across the three forests, and the ratio of RE to GEP decreased along the North–South Transect of Eastern China (NSTEC) (i.e. from the CBS to the DHS), with an average of 0.77 ± 0.06. Daily GEP was mainly influenced by temperature at CBS, whereas photosynthetic photon flux density was the dominant factor affecting the daily GEP at both QYZ and DHS. Temperature mainly determined the pattern of the interannual variations of ecosystem carbon exchange at CBS. However, water availability primarily controlled the interannual variations of ecosystem carbon exchange at QYZ. At DHS, NEP attained the highest values at the beginning of the dry seasons (autumn) rather than the rainy seasons (summer), probably because insufficient radiation and frequent fog during the rainy seasons hindered canopy photosynthesis. All the three forest ecosystems acted as a carbon sink from 2003 to 2005. The annual average values of NEP at CBS, QYZ, and DHS were 259 ± 19, 354 ± 34, and 434 ± 66 g C m−2 yr−1, respectively. The slope of NEP that decreased with increasing latitude along the NSTEC was markedly different from that observed on the forest transect in the European continent. Long‐term flux measurements over more forest ecosystems along the NSTEC will further help verify such a difference between the European forest transect and the NSTEC and provide insights into the responses of ecosystem carbon exchange to climate change in China. 相似文献
22.
Kristina Nystr?m Joana Abrantes Ana Margarida Lopes Béatrice Le Moullac-Vaidye Stéphane Marchandeau Jézabel Rocher Nathalie Ruvo?n-Clouet Pedro J. Esteves Jacques Le Pendu 《PLoS pathogens》2015,11(4)
RHDV (rabbit hemorrhagic disease virus), a virulent calicivirus, causes high mortalities in European rabbit populations (Oryctolagus cuniculus). It uses α1,2fucosylated glycans, histo-blood group antigens (HBGAs), as attachment factors, with their absence or low expression generating resistance to the disease. Synthesis of these glycans requires an α1,2fucosyltransferase. In mammals, there are three closely located α1,2fucosyltransferase genes rSec1, rFut2 and rFut1 that arose through two rounds of duplications. In most mammalian species, Sec1 has clearly become a pseudogene. Yet, in leporids, it does not suffer gross alterations, although we previously observed that rabbit Sec1 variants present either low or no activity. Still, a low activity rSec1 allele correlated with survival to an RHDV outbreak. We now confirm the association between the α1,2fucosyltransferase loci and survival. In addition, we show that rabbits express homogenous rFut1 and rFut2 levels in the small intestine. Comparison of rFut1 and rFut2 activity showed that type 2 A, B and H antigens recognized by RHDV strains were mainly synthesized by rFut1, and all rFut1 variants detected in wild animals were equally active. Interestingly, rSec1 RNA levels were highly variable between individuals and high expression was associated with low binding of RHDV strains to the mucosa. Co-transfection of rFut1 and rSec1 caused a decrease in rFut1-generated RHDV binding sites, indicating that in rabbits, the catalytically inactive rSec1 protein acts as a dominant-negative of rFut1. Consistent with neofunctionalization of Sec1 in leporids, gene conversion analysis showed extensive homogenization between Sec1 and Fut2 in leporids, at variance with its limited degree in other mammals. Gene conversion additionally involving Fut1 was also observed at the C-terminus. Thus, in leporids, unlike in most other mammals where it became extinct, Sec1 evolved a new function with a dominant-negative effect on rFut1, contributing to fucosylated glycan diversity, and allowing herd protection from pathogens such as RHDV. 相似文献
23.
Emanuele Luciani Patrick L. S. van Dun Jorge Eduardo Esteves Christian Lunghi Marco Petracca Liria Papa Olivier Merdy Anne J?kel Francesco Cerritelli 《PloS one》2015,10(6)
Objective
1) to assess the preparedness to practice and satisfaction in learning environment amongst new graduates from European osteopathic institutions; 2) to compare the results of preparedness to practice and satisfaction in learning environment between and within countries where osteopathy is regulated and where regulation is still to be achieved; 3) to identify possible correlations between learning environment and preparedness to practice.Method
Osteopathic education providers of full-time education located in Europe were enrolled, and their final year students were contacted to complete a survey. Measures used were: Dundee Ready Educational Environment Measure (DREEM), the Association of American Medical Colleges (AAMC) and a demographic questionnaire. Scores were compared across institutions using one-way ANOVA and generalised linear model.Results
Nine European osteopathic education institutions participated in the study (4 located in Italy, 2 in the UK, 1 in France, 1 in Belgium and 1 in the Netherlands) and 243 (77%) of their final-year students completed the survey. The DREEM total score mean was 121.4 (SEM: 1.66) whilst the AAMC was 17.58 (SEM:0.35). A generalised linear model found a significant association between not-regulated countries and total score as well as subscales DREEM scores (p<0.001). Learning environment and preparedness to practice were significantly positively correlated (r=0.76; p<0.01).Discussion
A perceived higher level of preparedness and satisfaction was found amongst students from osteopathic institutions located in countries without regulation compared to those located in countries where osteopathy is regulated; however, all institutions obtained a ‘more positive than negative’ result. Moreover, in general, cohorts with fewer than 20 students scored significantly higher compared to larger student cohorts. Finally, an overall positive correlation between students’ preparedness and satisfaction were found across all institutions recruited. 相似文献24.
Melanie Brügger Thomas Dmoulins G. Tuba Barut Beatrice Zumkehr Blandina I. Oliveira Esteves Kemal Mehinagic Quentin Haas Aline Schgler Marie-Anne Rameix-Welti Jean-Franois Elouët Ueli Moehrlen Thomas M. Marti Ralph A. Schmid Artur Summerfield Horst Posthaus Nicolas Ruggli Sean R. R. Hall Marco P. Alves 《PLoS pathogens》2021,17(7)
25.
Fabricio Fernandes Fontana Celso Tadeu Barbosa dos Santos Flavia Maria Esteves Ademir Rocha Geisa Ferreira Fernandes Cristiane Candida do Amaral Marcos Abel Domingues Zoilo Pires De Camargo Mario León Silva-Vergara 《Mycopathologia》2010,169(3):159-165
There is some evidence that dogs can be naturally infected by Paracoccidioides brasiliensis in endemic areas of paracoccidioidomycosis. In order to evaluate canine infection with this fungus, a survey with 149 urban
and 126 rural dogs was carried out using ELISA and intradermal tests with the gp43 antigen of P. brasiliensis in Uberaba, Minas Gerais state of Brazil. Forty-one out of 149 urban dogs were euthanatized and had their lungs, liver and
spleen removed. One slice from each viscera was processed for histopathological examination and the remaining was homogenized and then cultivated on mycobiotic agar
at room temperature and Fava-Netto medium at 35°C and observed for 12 weeks. Of urban dogs, 75 (50.3%) were small adult females,
56 (36%) were strays, while 93 (64%) had been donated to the municipal zoonosis control center. Nine (6.2%) had a positive
intradermal test without statistical differences regarding gender, race, nutritional status or origin. No colonies with microscopic
or morphology appearances resembling P. brasiliensis were isolated, nor granulomatous process or fungal structures were observed from histopathological examination. Eighty (53.6%)
of the urban dogs presented seroreactivity, without statistical differences regarding gender, race, nutritional state, origin,
or positive intradermal test. Of 126 rural dogs, 102 (80.5%) presented antibodies against gp43 antigen, and this was statistically
significant in relation to the reactivity detected in urban dogs (P = 0.0001). Thus, dogs are commonly infected with P. brasiliensis, but they probably present natural resistance to develop paracoccidioidomycosis. 相似文献
26.
Adriano Caliman Aliny F. Pires Francisco A. Esteves Reinaldo L. Bozelli Vinicius F. Farjalla 《Biodiversity and Conservation》2010,19(3):651-664
The sub-discipline of biodiversity and ecosystem functioning (BEF) has emerged as a central topic in contemporary ecological
research. However, to date no study has evaluated the prominence and publication biases in BEF research. Herein we report
the results of a careful quantitative assessment of BEF research published in five core general ecology journals from 1990
to 2007 to determine the position of BEF research within ecology, identify patterns of research effort within BEF research,
and discuss their probable proximal and historical causes. The relative importance of BEF publications increased exponentially
during the period analyzed and was significantly greater than the average growth of ecological literature, affirming the prominence
of BEF as a current paradigm in ecology. However, BEF research exhibited a strong bias toward experimental studies on terrestrial
plant communities, with significantly lower effort devoted to the functional aspects of biodiversity in aquatic systems, multiple
trophic level systems, and animal or microbial communities. Such trends may be explained by a combination of methodological
adequacy and historic epistemological differences in ecological thinking. We suggest that BEF researchers should direct more
effort toward the study of aquatic systems and animal communities, emphasize long-term and trophically complex experiments,
such as those with multi-trophic microbial communities, employ larger-scale field observational studies and increase the use
of integrative and theoretical studies. Many technical and analytical methodologies that are already employed in ecological
research, such as stable isotopes, paleobiology, remote sensing, and model selection criteria, can facilitate these aims.
Overcoming the above-mentioned shortcomings of current BEF research will greatly improve our ability to predict how biodiversity
loss will affect ecosystem processes and services in natural ecosystems. 相似文献
27.
28.
Cybele Esteves Almeida Barbara Charlotte Bach Maristela Lovato Flores Rogério Pereira Fontoura Stefanie Dickel Segabinazi Marta Helena Carlesso Aita 《European Journal of Wildlife Research》2010,56(1):101-104
Serum proteins from 47 healthy greater rheas (Rhea americana; male and female) were separated by electrophoresis in order to characterize normal reference ranges. Determination of total
protein concentration was performed through biuret reaction. The mean value of total serum protein was 4.4 g/dL. Absolute
concentrations of serum proteins were determined by agarose gel electrophoretic fractioning. Five fractions were analyzed:
albumin, alpha, beta1, beta2, and gamma globulins, and the average values in grams per deciliter were 2.39, 0.32, 0.45, 0.30,
and 0.79, respectively. 相似文献
29.
Ricardo Imbroisi Filho Alan C. Ochioni Amanda M. Esteves Joo G. B. Leandro Thain M. Demaria Mauro Sola-Penna Patricia Zancan 《Cell death & disease》2021,12(7)
Among the principal causative factors for the development of complications related to aging is a diet rich in fats and sugars, also known as the Western diet. This diet advocates numerous changes that might increase the susceptibility to initiate cancer and/or to create a tissue microenvironment more conducive to the growth of malignant cells, thus favoring the progression of cancer and metastasis. Hypercaloric diets in general lead to oxidative stress generating reactive oxygen species and induce endoplasmic reticulum stress. Our results demonstrate that mice bearing tumors fed with a Western diet presented bigger tumor mass with increased insulin sensitivity in these tissues. Several markers of insulin signaling, such as AKT phosphorylation and mTOR pathway, are promoted in tumors of Western diet-fed animals. This process is associated with increased macrophage infiltration, activation of unfolded protein response pathway, and initiation of epithelial–mesenchymal transition (EMT) process in these tumor tissues. Summing up, we propose that the Western diet accelerates the aging-related processes favoring tumor development.Subject terms: Melanoma, TOR signalling, Mechanisms of disease, Ageing 相似文献
30.
COLIN M. SHARPLES JOHN E. FA DIANA J. BELL 《Zoological Journal of the Linnean Society》1996,117(2):141-158
Craniometric data of nine characters from 260 skulls of Oryctolagus cuniculus from western Europe and northern Africa were gathered to examine phenotypic variation in size, using both univariate and multivariate analyses. Although animals from the northern part of Europe were found to be larger than those from southern Europe, variation in size occurred in a continuous cline. Skull size was positively correlated with latitude and negatively correlated with ambient temperature. On the basis of skull morphology, there is no evidence for separation of O. cuniculus into the two or more subspecies commonly described. Further data, particularly from genetic material, are required to clarify the taxonomic status of the rabbit in Europe. 相似文献