343 research outputs found
Peroxisomal APX knockdown triggers antioxidant mechanisms favourable for coping with high photorespiratory H2O2 induced by CAT deficiency in rice
The physiological role of peroxisomal ascorbate
peroxidases (pAPX) is unknown; therefore, we utilized pAPX4 knockdown rice and
catalase (CAT) inhibition to assess its role in CAT compensation under high
photorespiration. pAPX4 knockdown induced co-suppression in the expression of pAPX3.
The rice mutants exhibited metabolic changes such as lower CAT and glycolate
oxidase (GO) activities and reduced glyoxylate content; however, APX activity
was not altered. CAT inhibition triggered different changes in the expression
of CAT, APX and glutathione peroxidase (GPX) isoforms between non-transformed
(NT) and silenced plants. These responses were associated with alterations in
APX, GPX and GO activities, suggesting redox homeostasis differences. The
glutathione oxidation-reduction states were modulated differently in mutants,
and the ascorbate redox state was greatly affected in both genotypes. The pAPX
suffered less oxidative stress and photosystem II (PSII) damage and displayed
higher photosynthesis than the NT plants. The improved acclimation exhibited by
the pAPX plants was indicated by lower H2O2 accumulation, which was associated with
lower GO activity and glyoxylate content. The suppression of both pAPXs and/or
its downstream metabolic and molecular effects may trigger favourable
antioxidant and compensatory mechanisms to cope with CAT deficiency. This physiological
acclimation may involve signalling by peroxisomal H2O2, which minimized the
photorespiration.</p
Ecological study of socio-economic indicators and prevalence of asthma in schoolchildren in urban Brazil
BACKGROUND: There is evidence of higher prevalence of asthma in populations of lower socio-economic status in affluent societies, and the prevalence of asthma is also very high in some Latin American countries, where societies are characterized by a marked inequality in wealth. This study aimed to examine the relationship between estimates of asthma prevalence based on surveys conducted in children in Brazilian cities and health and socioeconomic indicators measured at the population level in the same cities. METHODS: We searched the literature in the medical databases and in the annals of scientific meeting, retrieving population-based surveys of asthma that were conducted in Brazil using the methodology defined by the International Study of Asthma and Allergies in Childhood. We performed separate analyses for the age groups 6-7 years and 13-14 years. We examined the association between asthma prevalence rates and eleven health and socio-economic indicators by visual inspection and using linear regression models weighed by the inverse of the variance of each survey. RESULTS: Six health and socioeconomic variables showed a clear pattern of association with asthma. The prevalence of asthma increased with poorer sanitation and with higher infant mortality at birth and at survey year, GINI index and external mortality. In contrast, asthma prevalence decreased with higher illiteracy rates. CONCLUSION: The prevalence of asthma in urban areas of Brazil, a middle income country, appears to be higher in cities with more marked poverty or inequality
Study of decays to the final state and evidence for the decay
A study of decays is performed for the first time
using data corresponding to an integrated luminosity of 3.0
collected by the LHCb experiment in collisions at centre-of-mass energies
of and TeV. Evidence for the decay
is reported with a significance of 4.0 standard deviations, resulting in the
measurement of
to
be .
Here denotes a branching fraction while and
are the production cross-sections for and mesons.
An indication of weak annihilation is found for the region
, with a significance of
2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html,
link to supplemental material inserted in the reference
An anthropogenic habitat facilitates the establishment of non-native birds by providing underexploited resources
Anthropogenic modification of habitats may reduce the resources available for native species, leading to population declines and extinction. These same habitats often have the highest richness of non-native species. This pattern may be explained if recently human-modified habitats provide novel resources that are more accessible to non-native species than native species. Using non-native birds in the Iberian Peninsula as a case study, we conduct a large-scale study to investigate whether non-native species are positively associated with human modified habitats, and to investigate whether this positive association may be driven by the presence of resources that are not fully exploited by native species. We do this by comparing the functional diversity and resource use of native and non-native bird communities in a recently human-modified habitat (rice fields) and in more traditional habitats in the Iberian Peninsula. The functional diversity of native bird communities was lower in rice fields, but non-native birds were positively associated with rice fields and plugged this gap. Differences in resource use between native and non-native species allowed non-native species to exploit resources that were plentiful in rice fields, supporting the role of underexploited resources in driving the positive association of non-native birds with rice fields. Our results provide a potential mechanism explaining the positive association of non-native species with anthropogenic habitats, and further work is needed to test if this applies more generally
Orçamento público, região e financiamento em saúde: rendas do petróleo e desigualdades entre municípios
Landscape structure, human disturbance and crop management affect foraging ground selection by migrating geese
It is well known that agricultural intensification has caused severe population declines among bird species which use farmland for breeding and overwintering, while migrating bird species may benefit from intensive farming, but in turn damage crops. Knowledge of the habitat selection of migrating birds is important from both a conservation and agro-economic point of view. We investigated the habitat preferences of three common migrating goose species: White-fronted Goose Anser albifrons, Bean Goose A. fabalis and Greylag Goose A. anser during the autumn of 2009 in western Poland. A total of 24 flocks of these species were identified. Geese preferred large, elevated fields that were remote from forests and human settlements but in close proximity to a lake. Geese selected maize stubbles and avoided winter cereals. They selected sites in landscapes with a lower diversity of crops. Flock size was negatively correlated with the proportion of pastures in the landscape, but it increased with field size, distance to forest and distance to town. Our results are in contrast with the paradigm that less intensive farmland positively influences habitat use by birds during foraging. We advise the delayed ploughing of stubbles with the aim of creating appropriate foraging habitats for geese and minimizing damage to cereal crops
Influence of the legislation on the advertisement of psychoactive medications in Brazil
Toxocariasis: America's Most Common Neglected Infection of Poverty and a Helminthiasis of Global Importance?
Sustentabilidade financeira e econômica do gasto público em saúde no nível municipal: reflexões a partir de dados de municípios mato-grossenses
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