944 resultados para maturity stages
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Background and Aims Bone metabolism involves understanding many factors, especially during puberty, when bone turnover is significant and the bone mass peak must be achieved as a protective factor of future bone health. The objective was to evaluate the behavior of formation and resorption bone biomarkers (BB) in function of biological maturation in female adolescents.Methods Evaluation of formation and resorption BB, osteocalcin (OC), bone alkaline phosphatase (BAP) and carboxyterminal telopeptide (S-CTx) by correlating them with bone mineralization, bone age and pubertal development in healthy female adolescents. Seventy-two volunteers were subdivided into groups according to chronological age/bone age (BA): 10 11 years (n=12), 12 13 years (n=16), 14 15 years (n=15) and 16 19 years (n=29). The following were evaluated: weight (kg), height (m), BMI (kg/m2), calcium intake (3-day 24h food recalls (mg/day), puberty events (Tanner stages), serum OC (ng/mL), BAP (U/L), S-CTx (ng/mL) and bone mineral density (BMD) as calculated by DXA (g/cm2) in the spine (L1-L4), proximal femur and whole body. The project was approved by the UNESP Ethics Committee.Results BB showed similar behaviors, with higher mean values for 10 12 years and when adolescents were in the B2-B3 Pubertal Maturation Stage (B2: BAP=110.16 U/L, OC=33.81ng/mL, S-CTx=1.66 ng/mL and B3: BAP=136.50 U/L, OC=39.15ng/mL and S-CTx=1.88 ng/mL; p<0.001). Mean BB values decreased with advancing BA and pubertal maturity.Conclusions BB values showed parallelism with peak height velocity and significant negative correlation with BMD in the different evaluated sites, with chronological and BA ; higher BMD values correlated with lower bone biomarker values.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The interface between stages of Eimeria funduli and hepatocytes of the experimentally infected killifish Fundulus similis was studied ultrastructurally. Parasitophorous vacuoles (PV's) in which meronts, macrogamonts, and microgamonts developed were lined by an inner, smooth membrane and an outer, ribosome-studded membrane. The outer membrane bordered on the cytoplasm of the host cell, whereas the inner one limited the PV. The origins of these membranes have not been determined with certainty, but images were observed in which both membranes appeared to be continuous with the outer nuclear membrane of the host cell. Furthermore, the outer PV membrane was continuous with membranes of rough endoplasmic reticulum in the host cell. For stages which were rapidly growing or differentiating, the inner membrane blebbed into the PV. Blebbing ceased and ribosomes detached from the outer membrane after maturation of the meront or fertilization of the macrogamont. Blebbing appears to be a mechanism by which nutrients transfer from the host to the parasite. During sporogony, the inner PV membrane acquired a thin layer of electron dense material, but otherwise membranes lining the PV remained intact. The two PV membranes, probably together with dense material of parasitic origin lining the inner membrane, appear to serve as the oocyst wall enclosing the sporocysts until they are released in the intermediate host.
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Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100–27,600 cal yr B.P.) and the latter part of MIS 3 (27,600–42,500 cal yr B.P.). During MIS 3, a series of transitions between warm- and cold-adapted taxa indicate that temperatures oscillated by ca. 2±–4±C every 1000–3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high and the jet stream may account for synchronous changes at the two sites. During MIS 2, shifts between mesic and xeric subalpine forests suggest changes in precipitation every 1000–3000 yr. Increases in Tsuga heterophylla pollen at 25,000 and 22,000 cal yr B.P. imply brief warmings. Minimum summer insolation and maximum global ice-volumes during MIS 2 correspond to cold and dry conditions. Fluctuations in precipitation at Little Lake do not correlate with changes in the Santa Barbara Basin and may be explained by variations in the strength of the glacial anticyclone and the position of the jet stream.
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Dry mass (DM) and total ammonia-N (TAN) excretion were determined in embryos, larvae (ZI-ZIX, Z = zoea ), and postlarvae (PL) at 1, 7, and 14 d after metamorphosis (PL1, PL7, and PL14) of Macrobrachium amazonicum. Animals in postmolt-intermolt (A-C) stages were sorted according to their developmental stages, and placed into incubation chambers (similar to 30 mL) for 2 h to quantify TAN excretion. After this period, analyses were carried out using Koroleff`s method for TAN determination. Individual TAN excretion generally increased throughout ontogenetic development and varied from 0.0090 +/- 0.0039 mu g TAN/individual/h in embryo to 1.041 +/- 0.249 mu g TAN/individual/h in PL14. There was no significant difference between embryo-ZIV and ZV-ZIX (P > 0.05), whereas PL1, PL7, and PL14 differed (P < 0.05) from each other. Higher increments in individual ammonia-N excretion were observed between ZIV-ZV, PL1-PL7, and PL7-PL14. Mass-specific excretion rates presented two groups, embryo-ZII (P > 0.05) and ZIII-PL14 (P > 0.05). The lowest value was found in embryo (0.17 +/- 0.07 mu g TAN/mg DM/h) and the maximum values in ZV and PL1 (0.65 +/- 0.25 and 0.64 +/- 0.27 mu g TAN/mg DM/h, respectively). Results indicate that metabolic rate is proportional to the body mass in M. amazonicum, during early life stages. Variations in ammonia excretion during this phase may be associated mainly with body size. Data obtained in the present study may be useful in developing and optimizing rearing techniques of M. amazonicum, such as the proportions between biofilter and rearing tank size, and stocking density in culture tanks or in transport bags.
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The developmental stages of the ovaries of the lobster Panulirus echinatus Smith, 1869 were characterized using macroscopic and microscopic features and the gonadosomatic relation (GSR). Based on monthly samples (November, 1999 to October, 2000), a total of 711 females were captured using gillnets. The dorsal region of the carapace was removed to evaluate the ovaries, which were dissected, weighted, preserved in Bouin`s solution, and submitted to histological procedures. The microscopic analysis of the ovaries was assessed by the presence of germinative cells in different developmental phases. When this analysis was combined with macroscopical observations (changes in color and volume of the gonads in the cephalothorax) and GSR, five developmental stages could be identified: immature (I), intermediate (II); pre-maturation (III); mature (IV) and post-spawning stage (V). Statistical analyses confirmed that GSR can be used as an indicator of developmental stage.
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Details of egg, larval, and pupal morphology are described and illustrated for Calycopis bellera (Hewitson) and C. janeirica (Felder), with a special emphasis on larval chaetotaxy. Wild-caught Calycopis females laid eggs on dead leaves in the laboratory, and the caterpillars successfully completed development on an artificial agar diet to which no leaves were added. Males and females of the sexually dimorphic C. bellera had been previously placed in different genera or different species groups. Calycopis janeirica had been chronically misidentified (and misspelled C. jeneirica). Males and females of this species appear to be correctly associated for the first time. Whereas C. bellera has five larval instars-as reported previously for C. caulonia-C. janeirica has four. Morphological characters of the immatures of C. bellera and C. janeirica are summarized in a table and compared with those of other reared Calycopis species.
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In epidemiology, the basic reproduction number R-0 is usually defined as the average number of new infections caused by a single infective individual introduced into a completely susceptible population. According to this definition. R-0 is related to the initial stage of the spreading of a contagious disease. However, from epidemiological models based on ordinary differential equations (ODE), R-0 is commonly derived from a linear stability analysis and interpreted as a bifurcation parameter: typically, when R-0 >1, the contagious disease tends to persist in the population because the endemic stationary solution is asymptotically stable: when R-0 <1, the corresponding pathogen tends to naturally disappear because the disease-free stationary solution is asymptotically stable. Here we intend to answer the following question: Do these two different approaches for calculating R-0 give the same numerical values? In other words, is the number of secondary infections caused by a unique sick individual equal to the threshold obtained from stability analysis of steady states of ODE? For finding the answer, we use a susceptibleinfective-recovered (SIR) model described in terms of ODE and also in terms of a probabilistic cellular automaton (PCA), where each individual (corresponding to a cell of the PCA lattice) is connected to others by a random network favoring local contacts. The values of R-0 obtained from both approaches are compared, showing good agreement. (C) 2012 Elsevier B.V. All rights reserved.
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We investigated modulation by ATP, Mg2+, Na+, K+ and NH4 (+) and inhibition by ouabain of (Na+,K+)-ATPase activity in microsomal homogenates of whole zoeae I and decapodid III (formerly zoea IX) and whole-body and gill homogenates of juvenile and adult Amazon River shrimps, . (Na+,K+)-ATPase-specific activity was increased twofold in decapodid III compared to zoea I, juveniles and adults, suggesting an important role in this ontogenetic stage. The apparent affinity for ATP ( (M) = 0.09 +/- A 0.01 mmol L-1) of the decapodid III (Na+,K+)-ATPase, about twofold greater than the other stages, further highlights this relevance. Modulation of (Na+,K+)-ATPase activity by K+ also revealed a threefold greater affinity for K+ ( (0.5) = 0.91 +/- A 0.04 mmol L-1) in decapodid III than in other stages; NH4 (+) had no modulatory effect. The affinity for Na+ ( (0.5) = 13.2 +/- A 0.6 mmol L-1) of zoea I (Na+,K+)-ATPase was fourfold less than other stages. Modulation by Na+, Mg2+ and NH4 (+) obeyed cooperative kinetics, while K+ modulation exhibited Michaelis-Menten behavior. Rates of maximal Mg2+ stimulation of ouabain-insensitive ATPase activity differed in each ontogenetic stage, suggesting that Mg2+-stimulated ATPases other than (Na+,K+)-ATPase are present. Ouabain inhibition suggests that, among the various ATPase activities present in the different stages, Na+-ATPase may be involved in the ontogeny of osmoregulation in larval The NH4 (+)-stimulated, ouabain-insensitive ATPase activity seen in zoea I and decapodid III may reflect a stage-specific means of ammonia excretion since functional gills are absent in the early larval stages.
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A new species of Mesabolivar is described from Brazilian forests: Mesabolivar delclaroi. The mating behaviour, postembryonic development, number of egg sacs and eggs, birth rate, number of instars, developmental time until adulthood, sex ratio and size of cephalothorax (per instar) were recorded. The sexual behaviour was described and categorized into four steps: courtship, pre-copulation, copulation and post-copulation. After hatching, individuals presented five instars until maturity. The mean number of eggs (42 +/- 16.6) and live births (31.5 +/- 3.4) of the first egg sac were significantly greater than that of a second one (23.8 +/- 3.8, and 19.25 +/- 3.9, respectively). The developmental time from birth to adulthood (130.8 +/- 9.6 days) did not differ significantly between egg sacs produced (128.61 +/- 11.1). The size of the cephalothorax did not differ among adults or between sexes. The sex ratio revealed a shift in favour of females (4: 3).
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Coccidiosis of the domestic fowl is a worldwide disease caused by seven species of protozoan parasites of the genus Eimeria. The genome of the model species, Eimeria tenella, presents a complexity of 55-60 MB distributed in 14 chromosomes. Relatively few studies have been undertaken to unravel the complexity of the transcriptome of Eimeria parasites. We report here the generation of more than 45,000 open reading frame expressed sequence tag (ORESTES) cDNA reads of E. tenella, Eimeria maxima and Eimeria acervulina, covering several developmental stages: unsporulated oocysts, sporoblastic oocysts, sporulated oocysts, sporozoites and second generation merozoites. All reads were assembled to constitute gene indices and submitted to a comprehensive functional annotation pipeline. In the case of E. tenella, we also incorporated publicly available ESTs to generate an integrated body of information. Orthology analyses have identified genes conserved across different apicomplexan parasites, as well as genes restricted to the genus Eimeria. Digital expression profiles obtained from ORESTES/EST countings, submitted to clustering analyses, revealed a high conservation pattern across the three Eimeria spp. Distance trees showed that unsporulated and sporoblastic oocysts constitute a distinct clade in all species, with sporulated oocysts forming a more external branch. This latter stage also shows a close relationship with sporozoites, whereas first and second generation merozoites are more closely related to each other than to sporozoites. The profiles were unambiguously associated with the distinct developmental stages and strongly correlated with the order of the stages in the parasite life cycle. Finally, we present The Eimeria Transcript Database (http://www.coccidia.icb.usp.br/eimeriatdb), a website that provides open access to all sequencing data, annotation and comparative analysis. We expect this repository to represent a useful resource to the Eimeria scientific community, helping to define potential candidates for the development of new strategies to control coccidiosis of the domestic fowl. (C) 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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The objective of this work was to identify genes that could be used as suitable markers for molecular recognition of phenological stages during coffee (Coffea arabica) fruit development. Four cultivars were evaluated as to their differential expression of genes associated to fruit development and maturation processes. Gene expression was characterized by both semi-quantitative and quantitative RT-PCR, in fruit harvested at seven different developmental stages, during three different seasons. No size polymorphisms or differential expression were observed among the cultivars for the evaluated genes; however, distinct expression profiles along fruit development were determined for each gene. Four out of the 28 evaluated genes exhibited a regular expression profile in all cultivars and harvest seasons, and, therefore, they were validated as candidate phenological markers of coffee fruit. The gene a-galactosidase can be used as a marker of green stage, caffeine synthase as a marker of transition to green and yellowish-green stages, and isocitrate lyase and ethylene receptor 3 as markers of late maturation.
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Evania appendigaster is a cosmopolitan wasp that deposits eggs in the oothecae of some species of cockroaches; its larvae then consume the cockroach eggs and embryos. It is a candidate for the biological control of cockroaches, but little is known about its basic biology. Here we describe the external morphology of all immature stages of E. appendigaster and compare them with the larvae of related species. The life cycle of E. appendigaster includes three larval instars, each with 13 body segments. Their mouthparts were generally reduced, except for the mandibles, which were always sclerotized and toothed, and were especially robust in second-instar larvae. Antennal and mouthpart sensilla were basiconic and difficult to observe. Larvae of E. appendigaster are similar in form to other described evaniid larvae, but quite different from the two available descriptions of larvae of gasteruptiid and aulacid wasps. Further descriptions of evaniid larvae will be useful in determining how widespread this morphology is within the family, and in understanding phylogenetic relationships within Hymenoptera.
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Tropical forests are experiencing an increase in the proportion of secondary forests as a result of the balance between the widespread harvesting of old-growth forests and the regeneration in abandoned areas. The impacts of such a process on biodiversity are poorly known and intensely debated. Recent reviews and multi-taxa studies indicate that species replacement in wildlife assemblages is a consistent pattern, sometimes stronger than changes in diversity, with a replacement from habitat generalists to old-growth specialists being commonly observed during tropical forest regeneration. However, the ecological drivers of such compositional changes are rarely investigated, despite its importance in assessing the conservation value of secondary forests, and to support and guide management techniques for restoration. By sampling 28 sites in a continuous Atlantic forest area in Southeastern Brazil, we assessed how important aspects of habitat structure and food resources for wildlife change across successional stages, and point out hypotheses on the implications of these changes for wildlife recovery. Old-growth areas presented a more complex structure at ground level (deeper leaf litter, and higher woody debris volume) and higher fruit availability from an understorey palm, whereas vegetation connectivity, ground-dwelling arthropod biomass, and total fruit availability were higher in earlier successional stages. From these results we hypothetize that generalist species adapted to fast population growth in resource-rich environments should proliferate and dominate earlier successional stages, while species with higher competitive ability in resource-limited environments, or those that depend on resources such as palm fruits, on higher complexity at the ground level, or on open space for flying, should dominate older-growth forests. Since the identification of the drivers of wildlife recovery is crucial for restoration strategies, it is important that future work test and further develop the proposed hypotheses. We also found structural and functional differences between old-growth forests and secondary forests with more than 80 years of regeneration, suggesting that restoration strategies may be crucial to recover structural and functional aspects expected to be important for wildlife in much altered ecosystems, such as the Brazilian Atlantic forest. (C) 2012 Elsevier B.V. All rights reserved.