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81.
82.
Angela Taboada D. Johan Kotze José M. Salgado Reyes Tárrega 《Journal of Insect Conservation》2011,15(4):573-590
Species rich semi-natural grasslands are disappearing across Europe, affecting invertebrate diversity negatively. In NW Spain,
the recent abandonment of traditional farming practices and the gradual decrease in grazing pressures are reducing the number
and extent of montane grasslands. In this context, we investigated the composition of carabid beetle (Coleoptera, Carabidae)
assemblages that inhabit semi-natural grasslands situated in long-term managed oak and beech forested landscapes. According
to their spatial arrangement, the studied grasslands were classified into: (1) interior or gap grasslands (small and completely
surrounded by continuous forest) and (2) exterior grasslands (large and connected to a variety of habitat types). Our results
indicate that, within each forested landscape, the gap and exterior grasslands harboured particular carabid assemblages (i.e.
exclusive or abundantly collected species), which were also distinct from the surrounding forest carabid fauna. Dissimilarities
between gap and exterior grasslands in each landscape suggest great carabid diversity at the regional scale. We also detected
species-specific responses as several carabids were mainly associated with gap or exterior grasslands. Consequently, in highly
modified forested landscapes, semi-natural grassland remnants may constitute great value for the protection of the carabid
fauna. Specifically, we recommend conservation strategies that preserve variety in grassland features and maintain proper
management activities to prevent the loss of specialised species and a decrease in regional carabid diversity. 相似文献
83.
Nguyen H. Dung Zhi Qiang Ou Luana Caron Lian Zhang Dinh T. Cam Thanh Gilles A. de Wijs Rob A. de Groot K. H. Jürgen Buschow Ekkes Brück 《Liver Transplantation》2011,1(6):1215-1219
The efficient coupling between lattice degrees of freedom and spin degrees of freedom in magnetic materials can be used for refrigeration and energy conversion. This coupling is enhanced in materials exhibiting the giant magnetocaloric effect. First principle electronic structure calculations on hexagonal MnFe(P, Si) reveal a new form of magnetism: the coexistence of strong and weak magnetism in alternate atomic layers. The weak magnetism of Fe layers (disappearance of local magnetic moments at the Curie temperature) is responsible for a strong coupling with the crystal lattice while the strong magnetism in adjacent Mn‐layers ensures Curie temperatures high enough to enable operation at and above room temperature. Varying the composition on these magnetic sublattices gives a handle to tune the working temperature and to achieve a strong reduction of the undesired thermal hysteresis. In this way we design novel materials based on abundantly available elements with properties matched to the requirements of an efficient refrigeration or energy‐conversion cycle. 相似文献
84.
85.
Fazan R de Oliveira M da Silva VJ Joaquim LF Montano N Porta A Chapleau MW Salgado HC 《American journal of physiology. Heart and circulatory physiology》2005,289(5):H1968-H1975
The goal of this study was to determine the baroreflex influence on systolic arterial pressure (SAP) and pulse interval (PI) variability in conscious mice. SAP and PI were measured in C57Bl/6J mice subjected to sinoaortic deafferentation (SAD, n = 21) or sham surgery (n = 20). Average SAP and PI did not differ in SAD or control mice. In contrast, SAP variance was enhanced (21 +/- 4 vs. 9.5 +/- 1 mmHg2) and PI variance reduced (8.8 +/- 2 vs. 26 +/- 6 ms2) in SAD vs. control mice. High-frequency (HF: 1-5 Hz) SAP variability quantified by spectral analysis was greater in SAD (8.5 +/- 2.0 mmHg2) compared with control (2.5 +/- 0.2 mmHg2) mice, whereas low-frequency (LF: 0.1-1 Hz) SAP variability did not differ between the groups. Conversely, LF PI variability was markedly reduced in SAD mice (0.5 +/- 0.1 vs. 10.8 +/- 3.4 ms2). LF oscillations in SAP and PI were coherent in control mice (coherence = 0.68 +/- 0.05), with changes in SAP leading changes in PI (phase = -1.41 +/- 0.06 radians), but were not coherent in SAD mice (coherence = 0.08 +/- 0.03). Blockade of parasympathetic drive with atropine decreased average PI, PI variance, and LF and HF PI variability in control (n = 10) but had no effect in SAD (n = 6) mice. In control mice, blockade of sympathetic cardiac receptors with propranolol increased average PI and decreased PI variance and LF PI variability (n = 6). In SAD mice, propranolol increased average PI (n = 6). In conclusion, baroreflex modulation of PI contributes to LF, but not HF PI variability, and is mediated by both sympathetic and parasympathetic drives in conscious mice. 相似文献
86.
87.
Pitanguy I Torres E Salgado F Pires Viana GA 《Plastic and reconstructive surgery》2005,115(3):729-34; discussion 735
Breast cancer is the tumor with the highest prevalence and incidence in women. Reduction mammaplasty is one of the most common procedures performed in Brazil by the plastic surgeon, and it is not uncommon for the surgeon to find a breast tumor during the operation or afterward, when the histopathological report is received. In this study, 2488 patient files were reviewed retrospectively. All patients had undergone reduction mammaplasty at the senior author's private clinic (the Ivo Pitanguy Clinic) between January of 1957 and December of 2002. Resected breast tissue was examined histopathologically. The objective of this study was to verify the occurrence of breast carcinoma found accidentally postoperatively. The senior author's team performed all of the operations and the same pathologist performed every histopathological examination. The histopathological test results were divided into two groups: benign lesions and tumors. The highest frequency of breast pathology was benign lesions, and of them, 80.8 percent involved fibrocystic changes and fibroadiposity. The tumor group was subdivided into benign tumors and malignant tumors. Among the benign tumors, fibroadenoma was the one most common, in 2.2 percent. The frequency of malignant tumors was 0.5 percent of all patients. Most of the histopathological lesions were found in patients between 30 and 50 years of age. A reduced number of patients had no lesions (3.7 percent). Lack of a pathological investigation or a cursory or hurried examination of any mammary tissue by the pathologist may overlook important lesions. In the analysis of these statistics, the concept of normal breast tissue was questioned. 相似文献
88.
89.
The brown alga Padina gymnospora has been studied due to their ecological significance and biochemical characteristics, including its high capability of heavy-metal accumulation. It has been suggested that the fucans are among the main polysaccharides related to metal binding and precipitation in cell walls. The main purpose of this work was to determine the localization of specific monosaccharides in P. gymnospora cells. In this way, the lectins Ulex europaeus agglutinin and Canavalia ensiformis concanavalin A with specificity to alpha-L-fucose and to terminal residues of alpha-D-glucosyl and alpha-D-mannosyl, respectively, were applied in young individuals. These revealed a preferential distribution of alpha-L-fucose at cell walls near the external surface in cortical cells and near the plasmalemma in cortical and medullar cells. The distribution of alpha-L-fucose in cell walls indicates the distribution of sulfated polysaccharides (sulfated fucans) that colocalize with the heavy-metal granules (Zn and Cd) described in previous works. Therefore, our results suggest that alpha-L-fucose participates in the nucleation and immobilization of heavy metals in P. gymnospora cell walls. An intense labeling of U. europaeus agglutinin and a weak labeling of concanavalin A was also observed in physodes. X-ray microanalysis revealed the presence of zinc, sulfur, and calcium in physodes of algae collected in a heavy-metal-contaminated area. Besides the affinity between polyphenolic compounds and heavy metals, it is suggested that the mechanism of metal binding by physodes could be related to the presence of sulfated fucans. 相似文献
90.
Laurila MR Salgado PS Makeyev EV Nettelship J Stuart DI Grimes JM Bamford DH 《Journal of structural biology》2005,149(1):111-115
The RNA-dependent RNA polymerase, QDE-1, is a component of the RNA silencing pathway in Neurospora crassa. The enzymatically active carboxy-terminal fragment QDE-1 DeltaN has been expressed in Saccharomyces cerevisiae in the presence and absence of selenomethionine (SeMet). The level of SeMet incorporation was estimated by mass spectrometry to be approximately 98%. Both native and SeMet proteins were crystallized in space group P2(1) with unit cell parameters a=101.2, b=122.5, c=114.4A, beta=108.9 degrees , and 2 molecules per asymmetric unit. The native and SeMet crystals diffract to 2.3 and 3.2A, respectively, the latter are suitable for MAD structure determination. 相似文献