Brazil entered the group of countries that had below-replacement fertility forty to fifty years after the onset of fertility transition. The last decade also marks the onset of the so-called ...postponement transition in Brazil. We build birth histories from the 2000 and 2010 Brazilian demographic censuses. We divide women into four groups according to years of schooling and apply a decomposition of rate and composition effects to estimate the extent to which within-group rate effects and compositional effects account for change in some fertility- and postponement-related variables. The rate effects explain changes that are not associated with education, while the compositional effects explain changes driven by the education gradient. In the case of fertility-related variables, there is a combination of rate and composition impacts on fertility decline. In the case of the postponement of childbearing, the education gradient (composition effect) explains most of the observed rise in postponement.
Perinatal asphyxia remains a significant cause of neonatal mortality and is associated with long-term neurodegenerative disorders. In the present study, we evaluated cellular and subcellular damages ...to brain development in a model of mild perinatal asphyxia. Survival rate in the experimental group was 67%. One hour after the insult, intraperitoneally injected Evans blue could be detected in the fetuses’ brains, indicating disruption of the blood-brain barrier. Although brain mass and absolute cell numbers (neurons and non-neurons) were not reduced after perinatal asphyxia immediately and in late brain development, subcellular alterations were detected. Cortical oxygen consumption increased immediately after asphyxia, and remained high up to 7 days, returning to normal levels after 14 days. We observed an increased resistance to mitochondrial membrane permeability transition, and calcium buffering capacity in asphyxiated animals from birth to 14 days after the insult. In contrast to ex vivo data, mitochondrial oxygen consumption in primary cell cultures of neurons and astrocytes was not altered after 1% hypoxia. Taken together, our results demonstrate that although newborns were viable and apparently healthy, brain development is subcellularly altered by perinatal asphyxia. Our findings place the neonate brain mitochondria as a potential target for therapeutic protective interventions.
In aquaculture, activities with anesthetic compounds are usually used in order to ensure the welfare of farmed fish, allowing handling out of water with decreased trauma by stress. Presently, there ...is no information about anesthetic action of eugenol in early life stages of Nile tilapia (Oreochromis niloticus). The objective of this study was to evaluate different concentrations of eugenol for larvae and juveniles of Nile tilapia. Sixty animals were used for each group of weight, group I = 0.02 g; group II = 0.08 g; group III = 0.22 g; group IV = 2.62 g; and group V = 11.64 g. The eugenol concentrations tested were 50, 75, 100, 125, 150 and 175 mg L-1. No mortality was reported during the tests with eugenol. Tilapia larvae with 0.02 g and juveniles around 11.64 g can be anesthetized with eugenol concentrations between 150 and 175 mg L-1, since they determine the shortest sedation time (23 and 72 seconds, for the group of lowest and highest weights, respectively).
Aims
To evaluate the occurrence, the characterization and identity of nodulating bacteria in symbiosis with
Mimosa
spp. in the ultramafic massif of Barro Alto, Goiás state, Brazil.
Methods
Nodules ...from field grown
M. somnians
and
M. claussenii
were sampled for bacteria isolation and
in situ
detection using microscopy. Isolates were characterized for their nodulation capacity on
M. pudica
and common bean, and their tolerance to Ni in culture medium. Bacteria were also partially identified by their 16S rRNA gene sequences. In addition,
recA
,
gyrB
,
nodC
and
nifH
genes from five representative isolates were sequenced for phylogenetic studies
.
Results
In situ
detection indicated the exclusive presence of
Paraburkholderia
sp. within the nodules. This identification was confirmed for most of the isolates by the analysis of their 16S rRNA gene sequences. All isolates identified as
Paraburkholderia
sp. were able to effectively nodulate
M. pudica
, but those tested in common bean produced ineffective nodules. Inoculation tests showed that these bacteria improved
M. pudica
growth in the absence of nitrogen. None of the isolates showed Ni tolerance. The concatenated 16S rRNA,
recA
and
gyrB
, and the
nodC
and
nifH
genes sequences demonstrated that the five selected isolates were closely related to
P. atlantica
.
Conclusions
This is the first report of
Paraburkholderia
present in nodules from
Mimosa
plants naturally growing in ultramafic soils. These results suggest that this symbiosis may be a factor to be considered as part of programs to restore ultramafic soils in Barro Alto areas degraded by mining activity.
This study aimed to evaluate sowing methods of different tropical grasses in integrated production systems on morphogenic and structural characteristics, chemical composition, and corn yield. The ...experiment was carried out in a completely randomized design, with a 3 x 3 + 1 factorial arrangement, with three forages: andropogon grass (Andropogon gayanus Kunth cv. Planaltina), massai grass (Megathyrsus maximum cv. Massai) and ruziziensis grass (Urochloa ruziziensis), three ways of sowing intercropped with corn (one row, two rows and broadcast) with four replications and corn in monoculture. Soil preparation, corrective practices and monitoring were carried out as recommended by the species. The results revealed that the sowing methods did not interfere with the interaction for morphogenic and structural characteristics of the grasses. Leaf elongation rate (LER) did not differ among grasses and sowing forms for Andropogon, Massai, and Ruziziensis grasses. There was an interaction effect (P<0.05) for leaf production (LP); the massai grass exhibited higher production compared to other grasses. The spread sowing method produced less leaf availability for the massai grass. There was no effect (P>0.05) of interaction for the variables of the chemical composition of grasses. Maize production was not altered due to the different consortia; however, a much lower value was found when producing corn in monoculture. The average production of intercropped corn was 3420 kg and ha-1, against 1680 kg of single cultivated corn. Massai grass and Ruziziensis grass is an attractive alternative for intercropping with corn in integrated systems.
The multidrug resistance proteins ABCB1, ABCC2 and ABCG2 are an energy-dependent efflux pump that functions in systemic detoxification processes. Physiologically expressed in a variety of tissues, ...most abundantly in the liver and intestinal epithelia, placenta, blood-brain barrier and various stem cells, until now, these pumps were not identified in goat ovarian tissue. Therefore, the aim of this study is to analyze ABCB1, ABCC2, and ABCG2 mRNA and protein expression in goat preantral follicles. Fragments (3 × 3 × 1 mm) from five pairs of ovary (
n
= 10) obtained from five goat were collected and immediately submitted to qPCR, Western blot, and immunofluorescence assay for mRNA detection and identification and localization of the ABC transporters, respectively. mRNA for
ABCB1
,
ABCC2
, and
ABCG2
and the presence of their proteins were observed on ovarian tissue samples. Positive marks were observed for the three transport proteins in all follicular categories studied. However, the marks were primarily localized in the oocyte of primordial, transition and primary follicle categories. In conclusion, goat ovarian tissue expresses mRNA for the ABCB1, ABCC2 and ABCG2 transporters and the expression of these proteins in the preantral follicles is a follicle-dependent stage.
The objective of this study was to evaluate increasing levels of nitrogen on and production and nutritive value of Andropogon and Massai grasses under the edaphoclimatic conditions of the Brazil ...denominated Middle Nort Region. The design used was completely randomized, with sixteen replicatios. The treatments consisted of nitrogen rates: 0, 150, 300, 450 and 600 kg N ha-1 and two forages, which were evaluated independently. The grasses used were Panicum maximum cv. Massai and Andropogon gayanus cv. Kunth. For Andropogon grass, there was an effect of nitrogen fertilization on thecharacteristics: leaf elongation rate, stem elongation rate, leaf senescence rate and leaf blade final length and, in all cases, the behavior was quadratic. Nitrogen also influenced the morphogenic characteristics: leaf appearance rate, leaf elongation rate, leaf senescence rate, phyllochron, leaf blade final length, number of live leaves per tiller and It was not significant for tiller population density of Massai grass, but the behavior varied according to the characteristic, in which leaf appearance rate and number of live leaves per tiller had decreasing linear behavior, while in phyllochron it increased linearly as nitrogen doses increased. Most of the productive characteristics of the grasses had increasing linear behavior (total biomass production of forage, leaf biomass and stem biomass in Andropogon grass, while in Massai grass, only the total forage production and dead material accumulation had an increasing linear behavior with increase of N doses. Quadratic effect only for masai leaf biomass behavior and there was practically no production of stems, affecting the leaf-stem ratio ) while the highest efficiency of nitrogen utilization was achieved with the application of 150 kg N ha-1 for the two grasses. Nitrogen fertilization also favored the nutritive value of the two grasses positively, with linear increase for crude protein and mineral matter contents, only in Massai, and reduction in the contents of neutral detergent fiber, acid detergent fiber and hemicellulose of grasses. Increasing doses of nitrogen fertilization favors the production, structure and chemical composition of the two grasses. However, the highest efficiency of use is obtained with the application of 150 kg N ha-1.
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