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991.
The acclimation responses of walnut leaf photosynthesis to the irradiance microclimate were investigated by characterizing the photosynthetic properties of the leaves sampled on young trees (Juglans nigraxregia) grown in simulated sun and shade environments, and within a mature walnut tree crown (Juglans regia) in the field. In the young trees, the CO(2) compensation point in the absence of mitochondrial respiration (Gamma*), which probes the CO(2) versus O(2) specificity of Rubisco, was not significantly different in sun and shade leaves. The maximal net assimilation rates and stomatal and mesophyll conductances to CO(2) transfer were markedly lower in shade than in sun leaves. Dark respiration rates were also lower in shade leaves. However, the percentage inhibition of respiration by light during photosynthesis was similar in both sun and shade leaves. The extent of the changes in photosynthetic capacity and mesophyll conductance between sun and shade leaves under simulated conditions was similar to that observed between sun and shade leaves collected within the mature tree crown. Moreover, mesophyll conductance was strongly correlated with maximal net assimilation and the relationships were not significantly different between the two experiments, despite marked differences in leaf anatomy. These results suggest that photosynthetic capacity is a valuable parameter for modelling within-canopies variations of mesophyll conductance due to leaf acclimation to light. 相似文献
992.
Pierre Czernic Djamel Gully Fabienne Cartieaux Lionel Moulin Ibtissem Guefrachi Delphine Patrel Olivier Pierre Jo?l Fardoux Clémence Chaintreuil Phuong Nguyen Frédéric Gressent Corinne Da Silva Julie Poulain Patrick Wincker Valérie Rofidal Sonia Hem Quentin Barrière Jean-Fran?ois Arrighi Peter Mergaert Eric Giraud 《Plant physiology》2015,169(2):1254-1265
993.
Bruno de Paulo Ribeiro Gustavo Capatti Cassiano Rodrigo Medeiros de Souza Dalila Nunes Cysne Marcos Augusto Grigolin Grisotto Ana Paula Silva de Azevedo dos Santos Cláudio Romero Farias Marinho Ricardo Luiz Dantas Machado Flávia Raquel Fernandes Nascimento 《PLoS neglected tropical diseases》2016,10(3)
Mechanisms involved in severe P. vivax malaria remain unclear. Parasite polymorphisms, parasite load and host cytokine profile may influence the course of infection. In this study, we investigated the influence of circumsporozoite protein (CSP) polymorphisms on parasite load and cytokine profile in patients with vivax malaria. A cross-sectional study was carried out in three cities: São Luís, Cedral and Buriticupu, Maranhão state, Brazil, areas of high prevalence of P. vivax. Interleukin (IL)-2, IL-4, IL-10, IL-6, IL-17, tumor necrosis factor alpha (TNF-α, interferon gamma (IFN-γ and transforming growth factor beta (TGF-β were quantified in blood plasma of patients and in supernatants from peripheral blood mononuclear cell (PBMC) cultures. Furthermore, the levels of cytokines and parasite load were correlated with VK210, VK247 and P. vivax-like CSP variants. Patients infected with P. vivax showed increased IL-10 and IL-6 levels, which correlated with the parasite load, however, in multiple comparisons, only IL-10 kept this association. A regulatory cytokine profile prevailed in plasma, while an inflammatory profile prevailed in PBMC culture supernatants and these patterns were related to CSP polymorphisms. VK247 infected patients showed higher parasitaemia and IL-6 concentrations, which were not associated to IL-10 anti-inflammatory effect. By contrast, in VK210 patients, these two cytokines showed a strong positive correlation and the parasite load was lower. Patients with the VK210 variant showed a regulatory cytokine profile in plasma, while those infected with the VK247 variant have a predominantly inflammatory cytokine profile and higher parasite loads, which altogether may result in more complications in infection. In conclusion, we propose that CSP polymorphisms is associated to the increase of non-regulated inflammatory immune responses, which in turn may be associated with the outcome of infection. 相似文献
994.
Vanessa Moura dos Reis Cláudia Santiago Karez Rodrigo Mariath Fernando Coreixas de Moraes Rodrigo Tomazetto de Carvalho Poliana Silva Brasileiro Ricardo da Gama Bahia Tito Monteiro da Cruz Lotufo Laís Vieira Ramalho Rodrigo Le?o de Moura Ronaldo Bastos Francini-Filho Guilherme Henrique Pereira-Filho Fabiano Lopes Thompson Alex Cardoso Bastos Leonardo Tavares Salgado Gilberto Menezes Amado-Filho 《PloS one》2016,11(4)
The abundance of reef builders, non-builders and the calcium carbonate produced by communities established in Calcification Accretion Units (CAUs) were determined in three Abrolhos Bank shallow reefs during the period from 2012 to 2014. In addition, the seawater temperature, the irradiance, and the amount and composition of the sediments were determined. The inner and outer reef arcs were compared. CAUs located on the inner reef shelf were under the influence of terrigenous sediments. On the outer reefs, the sediments were composed primarily of marine biogenic carbonates. The mean carbonate production in shallow reefs of Abrolhos was 579 ± 98 g m-2 y-1. The builder community was dominated by crustose coralline algae, while the non-builder community was dominated by turf. A marine heat wave was detected during the summer of 2013–2014, and the number of consecutive days with a temperature above or below the summer mean was positively correlated with the turf cover increase. The mean carbonate production of the shallow reefs of Abrolhos Bank was greater than the estimated carbonate production measured for artificial structures on several other shallow reefs of the world. The calcimass was higher than the non-calcareous mass, suggesting that the Abrolhos reefs are still in a positive carbonate production balance. Given that marine heat waves produce an increase of turf cover on the shallow reefs of the Abrolhos, a decrease in the cover represented by reef builders and shifting carbonate production are expected in the near future. 相似文献
995.
Frota ML Klamt F Dal-Pizzol F Schiengold M Moreira JC 《Redox report : communications in free radical research》2004,9(3):161-165
The effects of retinol on modulation of mdr genes in Sertoli cells were investigated. The hypothesis that free radical scavengers may attenuate the effect of retinol was also tested. Sertoli cells isolated from 15-day-old Wistar rats were cultured for 48 h and then treated with retinol for 24 h with or without free radical scavengers (1 mM mannitol, 0.1 mM Trolox or superoxide dismutase [200 U/ml]). Expression of mdr1, mdr2 and mdr3 genes was monitored by RT-PCR. Mitochondrial superoxide production was used as an index of ROS production. Expression of mdr1 and mdr3 was inhibited by retinol treatment (7 microM, 24 h), while mdr2 was not detected in response to any of the treatments. We also observed that retinol supplementation (7 microM, 24 h) increased superoxide production. The observed inhibition of mdr genes was attenuated by all co-treatments, suggesting that retinol-induced ROS are required for inhibition of mdr1 and mdr3 expression. The results suggest that retinol may play an important role in the modulation of the mdr gene family in cultured rat Sertoli cells and that these effects appear to be mediated by ROS. 相似文献
996.
In this study we investigated the relationships between dominance rank and access to shelters in captive groups of Lipophrys pholis and Coryphoblennius galerita, as well as the effects of group size and shelter availability. Dominance rank was strongly correlated with size in juvenile L. pholis and with sex and size in adult C. galerita, males being dominant over females of similar size. Access to shelters was significantly correlated with dominance rank.
For both species, most interactions occurred out of shelters. Direct disputes over shelters were always initiated by the dominant
fish and the initiator was always the winner. The rate of aggression per fish per unit time decreased with an increase in
the number of fish in L. pholis but not in C. galerita. No significant differences were found in groups differing in the number of shelters. C. galerita showed a higher rate of agonistic interactions and a higher proportion of overt aggression than L. pholis. It is suggested that one of the functions of agonistic interactions in these fishes is the control of a set of shelters,
in the network of pathways used by each individual within its home range, minimising the time required to hide in case of
danger.
Received in revised form: 29 January 2001
Electronic Publication 相似文献
997.
An increase in the dose of the Su(var)3-7 locus of Drosophila augments heterochromatin-promoted variegated silencing. The deduced protein sequence of Su(var)3-7 reveals seven widely spaced zinc fingers. We found that Su(var)3-7 has affinity for DNA in vitro and that the minimal protein sequence requirement for DNA binding is any module containing two zinc fingers and the interval between them. As Su(var)3-7 is a heterochromatin-associated protein, we tested its affinity for various satellite DNA sequences in vitro. The AATAT and 353-bp elements have the highest affinity. If affinity for satellite DNAs contributes to the presence of Su(var)3-7 in heterochromatin, a general affinity for DNA, or sequences yet to be determined, suggests a function in the genomic silencing of position-effect variegation: expansion of heterochromatin, whether continuous by spreading or discontinuous by pairing with sequence elements scattered through euchromatin, could use the affinity of Su(var)3-7 for DNA. 相似文献
998.
Ronald E. Blanton Lúcio M. Barbosa Eliana A. Reis Theomira M. Carmo Cláudio R. A. dos Santos Jackson M. Costa Peace T. Aminu Walter A. Blank Renato Barbosa Reis Isabel C. Guimar?es Luciano K. Silva Mitermayer G. Reis 《PLoS neglected tropical diseases》2015,9(3)
Urbanization is increasing across the globe, and diseases once considered rural can now be found in urban areas due to the migration of populations from rural endemic areas, local transmission within the city, or a combination of factors. We investigated the epidemiologic characteristics of urban immigrants and natives living in a neighborhood of Salvador, Brazil where there is a focus of transmission of Schistosoma mansoni. In a cross-sectional study, all inhabitants from 3 sections of the community were interviewed and examined. In order to determine the degree of parasite differentiation between immigrants and the native born, S. mansoni eggs from stools were genotyped for 15 microsatellite markers. The area received migrants from all over the state, but most infected children had never been outside of the city, and infected snails were present at water contact sites. Other epidemiologic features suggested immigration contributed little to the presence of infection. The intensity and prevalence of infection were the same for immigrants and natives when adjusted for age, and length of immigrant residence in the community was positively associated with prevalence of infection. The population structure of the parasites also supported that the contribution from immigration was small, since the host-to-host differentiation was no greater in the urban parasite population than a rural population with little distant immigration, and there had been little differentiation in the urban population over the past 7 years. Public health efforts should focus on eliminating local transmission, and once eliminated, reintroduction from distant migration is unlikely. 相似文献
999.
Clémence Béchade Tony Goovaerts Philippe Cougnet Laura Labriola Michel Jadoul Eric Goffin 《PloS one》2015,10(11)
Background
Buttonhole cannulation (BHC) has been associated with a greater risk of arteriovenous fistula (AVF)-related infections and septicemia than the rope ladder cannulation (RLC) in in-center hemodialysis (HD). Such infections have never been studied in satellite HD units.Study Design
Retrospective single center study.Setting and Participant
All patients in our satellite HD unit using a native AVF from 1 January, 1990, to 31 December, 2012.Study Period
Two different kinds of cannulation have been used during the study period: From 1 January, 1990 to 1, January, 1998 RLC was used in the unit (period 1). After 1 January, 1998 onwards, all the patients were switched within 3 months to BHC (period 2).Outcomes
Three different infectious events were observed during the two periods: local AVF infection, bacteremia, and combined infection. The aim of this study was to evaluate the incidence of AVF-related infections in our low-care HD unit and to determine whether BHC is associated with an increased risk of infection in this population.Results
162 patients were analyzed; 68 patients participated to period 1 and 115 to period 2. Sixteen infectious events occurred. Incidences of AVF-related infectious events were 0.05 [95% CI, 0.02–0.16] and 0.13/1000 AVF-days [95% CI, 0.0.8–0.23], for period 1 and 2 (p = 0.44) respectively. Recurrence of AVF-related infection was observed only during period 2. Unadjusted incidence rate ratio (IRR) of all infections was 0.39 (95%CI 0.12–1.37). Two complicated infections occurred during the study period: one in period 1 and one in period 2.Limitations
Observational retrospective single centre studyConclusions
BHC is not associated with an increased infectious incidence in our HD population from a satellite dialysis unit. In the rare patients with AVF-related infection it seems necessary to change cannulation sites as recurrence of infection might be an event more frequent with BHC. 相似文献1000.
G. Clément M.P. Bareille R. Goel D. Linnarsson E. Mulder W.H. Paloski J. Rittweger F.L. Wuyts J. Zange 《Journal of musculoskeletal & neuronal interactions》2015,15(1):60-68