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991.
Immunocompromised patients may develop severe chronic anaemia when infected by human parvovirus B19 (B19V). However, this is not the case in human immunodeficiency virus (HIV)-infected patients with good adherence to highly active antiretroviral treatment (HAART). In this study, we investigated the clinical evolution of five HIV-infected patients receiving HAART who had B19V infections confirmed by serum polymerase chain reaction. Four of the patients were infected with genotype 1a strains and the remaining patient was infected with a genotype 3b strain. Anaemia was detected in three of the patients, but all patients recovered without requiring immunoglobulin and/or blood transfusions. In all cases, the attending physicians did not suspect the B19V infections. There was no apparent relationship between the infecting genotype and the clinical course. In the HAART era, B19V infections in HIV-positive patients may be limited, subtle or unapparent.  相似文献   
992.
993.
In the treatment of lifestyle diseases, including metabolic syndrome and type 2 diabetes, it is important to lower body mass and fat tissue, and consequently, to increase insulin-sensitivity. Unfortunately, it often happens that low-energy diet which would lower overweight is not observed and, thus, it does not bring the expected effects. This paper discusses the influence of three diets—control, high-fructose, and high-fatty diet—on absorption of energy from food in order to transform it into body mass. The kJ/g ratio which describes this process has been calculated. In the tested diets, the addition of fructose (79.13?±?2.47 kJ/g) or fat (82.48?±?2.28 kJ/g) results in higher transformation of energy into body mass than in the case of control diet (89.60?±?1.86 kJ/g). The addition of Na[VO(O2)2(4,4′-Me2-2,2′-bpy)]?8H2O (where 4,4′-Me2-2,2′-bpy?=?4,4′-dimethyl-2,2′-bipyridine) results in statistical increase of that ratio: fructose diet (86.88?±?0.44 kJ/g), fat diet (104.68?±?3.01 kJ/g), and control diet (115.98?±?0.56 kJ/g), respectively. Fat diet statistically influences the decrease of kidney mass in comparison to the other diets. The application of the tested vanadium compound results also in the statistical decrease of the fatty liver caused by fructose and fat diet.  相似文献   
994.
Polyspecific associations are commonly observed in social animals, including primates, and have been interpreted as adaptations either to improve access to resources or to provide protection against predators. Mixed‐species associations between Wied's marmosets (Callithrix kuhlii) and golden‐headed lion tamarins (Leontopithecus chrysomelas) have been documented, and are unique among Atlantic forest primates. Both species are endemic to southern Bahia where part of the forest has been converted into cacao agroforests, which have been subjected to management intensification. Tree density and canopy connectivity decrease in more intensively managed agroforests, potentially increasing predation risk and the frequency of mixed‐species groups between these primates. Here, we test this hypothesis using a standardized, large spatial‐scale data set obtained from camera‐trapping in 30 sites across an agroforestry landscape mosaic. As expected, the frequency of mixed‐species groups increased in more intensively managed agroforests, but only relative to the total number of records of tamarins. Our results highlight that the benefits of mixed‐species groups can be asymmetrical among species and variable across the landscape. They corroborate that predation avoidance is an important advantage of mixed‐species groups in callitrichids, especially for conspicuous species living in smaller groups, such as the tamarin. Despite the importance of agroforests to conservation, our results indicate that management intensification can increase predation risk for species of conservation concern. To maintain the conservation value of agroforests, management practices should be planned to avoid any loss of canopy connectivity, taking into account the biodiversity vs. productivity trade‐off associated with shade management.  相似文献   
995.
996.
Many infectious agents transmitting through a contaminated environment are able to persist in the environment depending on the temperature and sanitation determined rates of their replication and clearance, respectively. There is a need to elucidate the effect of these factors on the infection transmission dynamics in terms of infection outbreaks and extinction while accounting for the random nature of the process. Also, it is important to distinguish between the true and apparent extinction, where the former means pathogen extinction in both the host and the environment while the latter means extinction only in the host population. This study proposes a stochastic-differential equation model as an approximation to a Markov jump process model, using Escherichia coli O157:H7 in cattle as a model system. In the model, the host population infection dynamics are described using the standard susceptible-infected-susceptible framework, and the E. coli O157:H7 population in the environment is represented by an additional variable. The backward Kolmogorov equations that determine the probability distribution and the expectation of the first passage time are provided in a general setting. The outbreak and apparent extinction of infection are investigated by numerically solving the Kolmogorov equations for the probability density function of the associated process and the expectation of the associated stopping time. The results provide insight into E. coli O157:H7 transmission and apparent extinction, and suggest ways for controlling the spread of infection in a cattle herd. Specifically, this study highlights the importance of ambient temperature and sanitation, especially during summer.  相似文献   
997.
The taxonomy of neotropical Salicaceae, a family that now includes the majority of the former Flacourtiaceae, has been problematic, especially because they display very diverse morphology and have several characteristics in common with many other families. Recent phylogenetic studies have proposed substantial changes at both family and generic levels. Considering the importance of anatomy as an aid for taxonomy, the gathering of anatomical data for the family is fundamental to help clarify the taxonomic problems. Leaves belonging to Abatia americana (four samples), Banara brasiliensis (2), Casearia arborea (4), C. decandra (5), C. gossypiosperma (2), C. obliqua (1), C. sylvestris (3), C. ulmifolia (3), Prockia crucis (3), and Xylosma prockia (4) and the closely related Carpotroche brasiliensis (3) from Achariaceae, were studied by standard microscopy techniques. The leaves were anatomically described, emphasizing their differences and similarities. Similar characters for the neotropical Salicaceae (former Flacourtiaceae) and Salicaceae strictu sensu were recognized, such as the presence of salicoid leaf teeth, brachyparacytic stomata, secondary growth of the petiole, abundance of crystals, collateral and arch-shaped vascular system at the midrib, and sclerenchyma accompanying the bundles. These data demonstrate that leaf anatomy can provide evidence to assist with the taxonomy of Salicaceae, at family, generic, and specific levels.  相似文献   
998.
The anatomy of leaves and inflorescence peduncles was studied in species of Monotrema (4), Stegolepis (1) and Saxofridericia (1), aiming to contribute to the taxonomy of Rapateaceae. The form and structure of leaf blade midrib and the form of the inflorescence peduncle are diagnostic characteristics for the studied species. Monotrema is distinguished by: epidermal and vascular bundle outer sheath cells containing phenolic compounds in both organs; leaf blade with palisade and spongy chlorenchyma, arm-parenchyma, and air canals between the vascular bundles; leaf sheath with phenolic idioblasts in the mesophyll; inflorescence peduncle with tabular epidermal cells and air canals in the cortex and pith. Such characteristics support the recognition of Monotremoideae, which includes Monotrema. Stegolepis guianensis is distinguished by thick-walled epidermal cells and a plicate chlorenchyma in both organs; leaf blade with subepidermal fiber strands in abaxial surface and a heterogeneous mesophyll; inflorescence peduncle with rounded epidermal cells, a hypodermis with slightly thick-walled cells, and a pith with isodiametric cells and vascular bundles. Saxofridericia aculeata is distinguished by papillate epidermal cells in both organs; unifacial leaf blade with subepidermal fiber strands in both surfaces and a regular chlorenchyma; leaf sheath with a hypodermis in both surfaces and fiber bundles in the mesophyll; inflorescence peduncle with an undefined cortex and a hypodermis with thick-walled cells. S. guianensis shares few characteristics with S. aculeata, supporting their placement in different tribes.  相似文献   
999.
Polyamines (PAs) belong to plant growth regulators and in complex with classical phytohormones take part in regulation of seed dormancy and germination. Although the impact of reactive oxygen (ROS) and nitrogen (RNS) species on seed germination is well described, the cross talk of PAs with ROS/RNS has never been analyzed. Due to the close connection of PAs and ethylene biosynthetic pathways to arginine (Arg)-dependent NO biosynthesis we investigated production of nitric oxide (NO), peroxynitrite (ONOO?) and the level of O 2 ?? or H2O2 in apple embryos, germination of which was PA regulated. PAs: putrescine (Put) and spermidine (Spd) in contrast to spermine (Spm) stimulated germination of apple embryos. Among amino acids, stimulation of germination was observed in Arg and ornithine (Orn) only. Dormancy removal of embryos by PAs was associated with increased accumulation of H2O2 and O 2 ?? in embryonic axes. At the same stage of completion of sensu stricto germination the stimulatory effect of PAs (Put and Spd) and amino acids, mainly Arg and Orn, was accompanied by enhanced NO and ONOO? production in embryonic axis. The beneficial effect of PAs (Put and Spd) and their precursors on germination of apple embryos was removed by NO scavenging, suggesting a crucial role of NO in termination of embryo germination and radicle growth. Moreover, activity of polyamine oxidase in embryo axes was greatly enhanced by embryo fumigation with NO. Our data demonstrate the interplay of RNS/ROS with PAs and point to NO action as an integrator of endogenous signals activating germination.  相似文献   
1000.
The objective of this study was to evaluate the effect of temperature, type of mineral substrate, and type and amount of feed on the growth of Chironomus calligraphus as a subsidy for the production of Chironomus larvae to feed the fish. Egg production was evaluated at 22, 25, and 28?°C on fine (0.074–0.210?mm), or silty sand (0.002–0.250?mm), and no mineral substrate as control. For larval production, 0.10, 0.20, and 0.30?mg/larvae of fish feed, poultry feed, or turkey manure were used as food. The highest number of egg masses was produced when mineral substrates and 25?°C were used, but the higher number of eggs/mass was registered in the control. Therefore, the total number of eggs and hatched larvae produced was the same in the presence or in the absence of mineral substrates (p?>?0.05). The best results for survival and growth were recorded for larvae reared with fish or poultry food. The increase in the amount of feed was correlated with weight gain only for larvae fed with poultry feed, with no reduction in survival.  相似文献   
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