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301.
Cipo Canastero (Asthenes luizae) is a bird endemic to Brazilian mountaintops, inhabiting rock outcrop habitats of the campos rupestres in the southern Espinhaço Range. Available data about Cipo Canastero’s breeding biology are scarce, incomplete or inconsistent. All nests found to date were built in the plant Vellozia nivea. Based on 84 nests found from 2009 to 2017 in four sites at Serra do Cipó, we described in detail their nesting habits focusing on three groups of characters: nest architecture, composition, and placement. Also, we described nest building. Our major new findings on the nesting habits of A. luizae were: three nest layers distinguishable, inner lining covering the entire nest interior, tunnels and tubes are absent, and the nest sites are not restricted to V. nivea. We recorded a wide range of nest sites, from ground, grasses and rupicolous bromeliads to shrubs and trees, including at least 30 supporting-plant species. Nest supports varied among study sites. Nest building lasted 22 days (one nest) and was done by both members of the pair. Our data can be useful for species conservation and contribute to the knowledge of the natural history of the genus Asthenes.  相似文献   
302.
The Breast Cancer Association Consortium (BCAC) has been established to conduct combined case-control analyses with augmented statistical power to try to confirm putative genetic associations with breast cancer. We genotyped nine SNPs for which there was some prior evidence of an association with breast cancer: CASP8 D302H (rs1045485), IGFBP3 -202 C --> A (rs2854744), SOD2 V16A (rs1799725), TGFB1 L10P (rs1982073), ATM S49C (rs1800054), ADH1B 3' UTR A --> G (rs1042026), CDKN1A S31R (rs1801270), ICAM5 V301I (rs1056538) and NUMA1 A794G (rs3750913). We included data from 9-15 studies, comprising 11,391-18,290 cases and 14,753-22,670 controls. We found evidence of an association with breast cancer for CASP8 D302H (with odds ratios (OR) of 0.89 (95% confidence interval (c.i.): 0.85-0.94) and 0.74 (95% c.i.: 0.62-0.87) for heterozygotes and rare homozygotes, respectively, compared with common homozygotes; P(trend) = 1.1 x 10(-7)) and weaker evidence for TGFB1 L10P (OR = 1.07 (95% c.i.: 1.02-1.13) and 1.16 (95% c.i.: 1.08-1.25), respectively; P(trend) = 2.8 x 10(-5)). These results demonstrate that common breast cancer susceptibility alleles with small effects on risk can be identified, given sufficiently powerful studies.  相似文献   
303.
Nectomys squamipes is a semi-aquatic rodent with a wide geographic range in Brazilian forests and savannas. This species is a host for several parasites associated with aquatic environments, especially Schistosoma mansoni, and thus its spatial pattern may influence some diseases’ patterns. Here we present important aspects of water rat spatial behaviour, including technical and ecological aspects. Water rats were studied by live trapping in rivers and in gallery forests between January 2005 and August 2008, with a total sampling effort of 9511 trap-nights. We also studied some animals through radio tracking and the spool-and-line technique. Water rat movement was distributed evenly between the terrestrial and aquatic environments. Nectomys squamipes occurrence in small tributaries was higher than in larger and lotic rivers. Both home range, the conventional two-dimensional approach, and home length, a one-dimensional approach, proved to be useful to study N. squamipes, depending on the shape of the water body used by the individual. Although Nectomys squamipes’ home length was positively correlated with body weight, sex was also important to explain home length variation; at similar body weights, males have larger home lengths than females. Males explored larger areas during the rainy season, likely in search of females, as this is the water rat reproductive season in Atlantic forest. In contrast, females explored larger areas during the dry season, likely looking for additional food supplies as a result of deficient water rat food supplies during the Atlantic forest dry season. Females overlapped home lengths with more than one male, and males with more than one female, suggesting a promiscuous mating system for this species.  相似文献   
304.
At the end of their product life cycle, tires require special handling and treatment in order to avoid damaging the environment and society. Reverse Logistics (RL) is necessary to manage this type of solid waste. In Brazilian cities, collection is one of the bottlenecks. One of the main difficulties in this process is enabling joint-action between the main stakeholders: Final consumers, the government and private companies. The main objective of this paper is to identify e implement opportunities for improvement in the collection phase of end-of-life tires through action-research, involving simultaneous participation between public and private organizations. The motive for this is that the knowledge generated can serve as a basis of information and references which aid in decision-making for public authorities who need to start similar programs or improve existing ones. The Action-Research occurred in a Brazilian city with less than 100,000 inhabitants, which fits the profile of 94.91% of the country’s municipalities. Final results proved the efficiency of the action-research proposal; after implementing the changes, the monthly collections grew by 50% (action), and the Action-Research team was able to generate and document knowledge which can now help other cities to improve their own processes.  相似文献   
305.
Mitochondria are highly dynamic and functionally versatile organelles that continuously fragment and fuse in response to different physiological needs of the cell. The list of proteins that strictly regulate the morphology of these organelles is constantly growing, adding new players every day and new pieces to the comprehension and elucidation of this complex machinery. The structural complexity of mitochondria is only paralled by their functional versatility. Indeed, changes in mitochondria shape play critical roles in vertebrate development programmed cell death and in various processes of normal cell physiology, such as calcium signaling, reactive oxygen species production, and lifespan. Here, we present the latest findings on the regulation of mitochondrial dynamics and some of their physiological roles, focusing on cell migration. In cells where migration represents a crucial function in their physiology, such as T and tumoral metastatic cells, mitochondria need to be fragmented and recruited to specific subcellular regions to make movement possible. In depth analysis of this role of mitochondrial dynamics should help in identifying potential targeted therapy against cancer or in improving the immune system’s efficiency.  相似文献   
306.
The efficacy and safety of biological molecules in cancer therapy, such as peptides and small interfering RNAs (siRNAs), could be markedly increased if high concentrations could be achieved and amplified selectively in tumour tissues versus normal tissues after intravenous administration. This has not been achievable so far in humans. We hypothesized that a poxvirus, which evolved for blood-borne systemic spread in mammals, could be engineered for cancer-selective replication and used as a vehicle for the intravenous delivery and expression of transgenes in tumours. JX-594 is an oncolytic poxvirus engineered for replication, transgene expression and amplification in cancer cells harbouring activation of the epidermal growth factor receptor (EGFR)/Ras pathway, followed by cell lysis and anticancer immunity. Here we show in a clinical trial that JX-594 selectively infects, replicates and expresses transgene products in cancer tissue after intravenous infusion, in a dose-related fashion. Normal tissues were not affected clinically. This platform technology opens up the possibility of multifunctional products that selectively express high concentrations of several complementary therapeutic and imaging molecules in metastatic solid tumours in humans.  相似文献   
307.
Seasonal fluctuations in day length regulate important aspects of plant development such as the flowering transition or, in potato (Solanum tuberosum), the formation of tubers. Day length is sensed by the leaves, which produce a mobile signal transported to the shoot apex or underground stems to induce a flowering transition or, respectively, a tuberization transition. Work in Arabidopsis, tomato and rice (Oryza sativa) identified the mobile FLOWERING LOCUS T (FT) protein as a main component of the long-range 'florigen', or flowering hormone, signal. Here we show that expression of the Hd3a gene, the FT orthologue in rice, induces strict short-day potato types to tuberize in long days. Tuber induction is graft transmissible and the Hd3a-GFP protein is detected in the stolons of grafted plants, transport of the fusion protein thus correlating with tuber formation. We provide evidence showing that the potato floral and tuberization transitions are controlled by two different FT-like paralogues (StSP3D and StSP6A) that respond to independent environmental cues, and show that an autorelay mechanism involving CONSTANS modulates expression of the tuberization-control StSP6A gene.  相似文献   
308.
庆大霉素/水杨酸/壳聚糖复方纳米粒的制备及体外释放   总被引:1,自引:0,他引:1  
通过壳聚糖与三聚磷酸钠的离子交联作用制备了具有拮抗庆大霉素耳毒性功效的庆大霉素/水杨酸复方壳聚糖纳米粒。用紫外分光光度计、纳米粒度仪和Zeta电位仪、透射电子显微镜、扫描电子显微镜、傅里叶变换红外光谱仪和X射线衍射仪等考察了壳聚糖纳米粒的粒径、zeta电位、形态、载药能力及体外释放行为。结果显示复方纳米粒为球形,平均粒径为40 nm;庆大霉素与水杨酸的包封率分别为(91.24±0.24)%和(80.75±0.15)%,载药量分别为(34.15±1.02)%和(38.35±0.48)%;在体外释放试验中,庆  相似文献   
309.
群体决策的模糊Borda数规则   总被引:5,自引:0,他引:5  
对于决策个体和决策群体的偏爱均为模糊结构的群体决策问题 ,建立了模糊 Borda数规则 ,并研究了它的性质和满足模糊偏爱公理系的情况。在模糊偏爱的意义下 ,扩展了确定性下的 Borda数规则。  相似文献   
310.
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