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111.
The composition and diversity of fungal communities associated with three endangered orchid species, Hadrolaelia jongheana, Hoffmannseggella caulescens, and Hoffmannseggella cinnabarina, found in different vegetation formations of the Atlantic Forest were determined by constructing clone libraries and by applying diversity and richness indices. Our results demonstrated the presence of Basidiomycetes. Sebacinales (81.61 %) and Cantharellales (12.10 %) were the dominant orders and are potential candidates for orchid mycorrhizal fungi. The Ascomycetes identified included the Helotiales (29.31 %), Capnodiales (18.10 %), and Sordariales (10.34 %), among others. These orders may represent potentially endophytic fungi. A Shannon–Wiener diversity index (H′) analysis showed a relatively high fungal community diversity associated with these tropical orchids. This diversity may offer greater flexibility in terms of the adaptation of the plants to changing environmental conditions and the potential facilitation of reintroduction programs. The Simpson diversity index values showed that all of the libraries included dominant species, and a LIBSHUFF analysis showed that the fungal communities were structurally different from each other, suggesting an influence of local factors on this diversity. This study offers important information for the development of conservation strategies for threatened and endemic species of Brazilian flora in an important and threatened hotspot.  相似文献   
112.
Eucalypt cultivation is an important economic activity worldwide. In Portugal, Eucalyptus globulus plantations account for one-third of the total forested area. The nutritional requirements of this crop have been well studied, and nitrogen (N) is one of the most important elements required for vegetal growth. N dynamics in soils are influenced by microorganisms, such as diazotrophic bacteria (DB) that are responsible for biological nitrogen fixation (BNF), so the aim of this study was to evaluate and identity the main groups of DB in E. globulus plantations. Samples of soil and root systems were collected in winter and summer from three different Portuguese regions (Penafiel, Gavião and Odemira). We observed that DB communities were affected by season, N fertilization and moisture. Furthermore Bradyrhizobium and Burkholderia were the most prevalent genera in these three regions. This is the first study describing the dynamic of these bacteria in E. globulus plantations, and these data will likely contribute to a better understanding of the nutritional requirements of eucalypt cultivation and associated organic matter turnover.  相似文献   
113.
傅卓  任少敏  高晓峰  杨光路  李筱贺 《生物磁学》2014,(6):1095-1096,1100
目的:探讨血管细胞粘附分子-1(VCAM-1)的检测在儿童过敏性紫癜(AP)早期肾损伤中的临床意义。方法:选择明确诊断为AP 患儿85 例,均为早期无肾损害的AP病儿。根据第七版诸福棠实用儿科学有关章节的诊断标准和随访结果,进一步将研究对象分为有肾损害AP 为APN 组,无肾损害AP为AP 组,于同时间、同群体中选择健康儿童35 名为对照组。应用ELISA 法分别检测三组患儿早期无肾损害时血VCAM-1 的含量,分析血VCAM-1在儿童过敏性紫癜早期肾损伤中的临床意义。结果:APN 组血VCAM-1 水平均高于AP组和正常对照组;AP 组亦高于正常对照组,差异均有统计学意义(P〈0.01)。结论:对早期无肾损害的AP病儿,检测血浆VCAM-1 对AP发生APN 的预后诊断有重要的临床意义。  相似文献   
114.
We present a computational study aimed at exploring the sensorimotor cortex modulation of the behaviour of dorsal column nuclei, specifically the impact of synaptic parameters, during both sleep and waking conditions. On the basis of the circuit proposed by Canedo et al. (2000), we have developed realistic computational models that have been tested with simultaneous electrocorticographic as well as intracellular cuneate recordings performed in anaesthetized cats. The results show that, (1) under sleep conditions, the model can block the transmission of afferent sensory information and, (2) operations expected during wakefulness, such as filtering and facilitation, can be performed if synaptic parameters are appropriately tuned. Action Editor: Steve Redman  相似文献   
115.
目的:脑卒中是威胁人类健康三大疾病之一,是我国成人致残的首要原因,其中80%是缺血性卒中。本文意在研究血清胆红素水平与缺血性卒中严重程度、发病机理以及颈动脉粥样硬化斑块的关系,以进一步为防治缺血性卒中的发生、发展提供新的途径。方法:选择缺血性脑卒中患者(观察组)150例和同期健康体检者(对照组)150例,分别测定两组的血清总胆红素水平(TBIL)、间接胆红素(DBIL)、直接胆红素(IBIL),并对病例组进行TOAST分型、NIHSS评分及颈部血管超声检查。比较两组间血清胆红素,及观察组内不同分型组间血清胆红素的差异。结果:缺血性卒中患者TBIL、DBIL水平显著高于正常对照组,差异具有统计学意义(P〈0.05)。缺血性卒中患者按TOAST分型各亚型间血清TBIL、DBIL、IBIL水平差异无统计学意义(P〉0.05)。中重型脑梗死组与轻型脑梗死组比较,血清TBIL、DBIL、IBIL浓度均明显升高,差别具有统计学意义(P〈0.05)。缺血性卒中患者中有动脉粥样硬化斑块形成组血清TBIL、DBIL水平低于颈部动脉内膜光滑、完整者组,差别有统计学意义(P〉0.05)。结论:缺血性卒中患者血清胆红素升高,参与急性应激反应,可能作为衡量缺血性卒中严重程度的指标之一;高水平血清胆红素可能预防颈动脉粥样硬化斑块的形成,从而预防缺血性卒中的发生。  相似文献   
116.
The aim of this study was to identify the species of ked infesting dogs in the cities of central Poland. A total of 510 dogs were observed between June and September 2015. The presence of keds was noted in 182 (35.7%) animals. Keds were more prevalent in female (38.0%) than in male (33.2%) dogs, and were more frequently found in animals younger than 1 year (46.2%) and in long‐haired dogs (36.6%). The body areas most heavily colonized by keds were the groin (35.4%) and neck (21.4%). A total of 904 keds were isolated from dogs, including Hippobosca equina (Diptera: Hippoboscidae) (17.2%), Lipoptena cervi (Diptera: Hippoboscidae) (32.0%), and two species not previously encountered in Poland: Hippobosca longipennis (45.0%) and Lipoptena fortisetosa (5.9%). Hippoboscidae may act as vectors of pathogens and any shifts in their geographic range may lead to the spread of new diseases affecting animals.  相似文献   
117.
118.
Many species of tropical amphibians are restricted to very small ranges, and this microendemism coupled with ongoing habitat loss and susceptibility to emerging pathogens imperils the long-term persistence of these species. Incomplete taxonomic and distributional knowledge may obscure conservation assessment, particularly in putatively widespread species that are typically considered to be of Least Concern in Red List assessments, but that in fact may constitute complexes of partly microendemic species. Such is the case in the Steindachner’s Robber Frog, Ischnocnema guentheri which, together with the recently recognized Ischnocnema henselii, is thought to occupy most of the Brazilian Atlantic Forest. To test whether these taxa may constitute a species complex of range-restricted and thus potentially threatened species, we analyzed 160 samples of I. guentheri and/or I. henselii for two molecular markers, 16S rRNA (16S) and recombination activation gene 1 (RAG1). To verify the monophyly of the complex, closely related species were also included in the 16S analysis. Congruent evidence from the molecular data and from analyses of advertisement calls support the existence of six distinct species within the complex: I. guentheri and I. henselii as well as four candidate new species. The lineages are distributed as a mosaic in the Atlantic Forest and are sympatric at some localities without indication of admixture. Their phylogeographical pattern partially agrees with paleo-models for the Atlantic Forest, but also suggests the existence of micro-refugia in less stable areas. I. guentheri, previously considered to be widespread, was found only in its type locality, a reserve within the urban area of Rio de Janeiro city. Although none of the species studied appears highly threatened with extinction, we recommend their IUCN threat status to be re-evaluated carefully for the next comprehensive update of the Red List of Brazil’s amphibians.  相似文献   
119.
Summary

Bathypecten vulcani is considered a relict species from the Paleozoic, based on shell characteristics such as the presence of calcite prisms. To date, it is the only pectinid species reported from hydrothermal ecosystems. Histological and ultrastructural studies show that spermatogenesis is identical to that of littoral pectinids. The spermatozoon has a 2.7 μm long pyriform head and a 40 μm flagellum. The four mitochondria of the mid-piece are about 1.2 μm in diameter. The nucleus contains dense chromatin fibres and possesses a wide, shallow (0.1 μm) anterior fossa and a narrow, deeper (0.2 μm) posterior nuclear fossa. Comparison of the ultrastructural characteristics of the spermatozoon of B. vulcani with those of littoral pectinids shows that they can be used as a diagnostic feature of this species. In particular, its acrosome characters will be a useful complement to the shell characters in the study of the phylogenetic position of this species in relation to other pectinids.  相似文献   
120.
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