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1.
Analysing Betula litwinowii encroachment and reforestation in the Kazbegi region,Greater Caucasus,Georgia
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Aims
The encroachment of tree and shrub species in high mountains is an increasing worldwide phenomenon, which is expected to dramatically alter high‐mountain ecosystems and their functioning. Moreover it indicates in some cases a reforestation process, which will result in important ecological and social benefits, including carbon sequestration and protection against landslides. We therefore examined the spatial extent of forest growth and shrub encroachment mainly of birch (Betula litwinowii) in the sub‐alpine belt of the Central Greater Caucasus between 1987 and 2010 and its relation to topographic site conditions.Location
Kazbegi district, Central Greater Caucasus, Georgia.Methods
We analysed 155 vegetation relevés sampled in 2009, 2011 and 2015, mainly derived from the Caucasus Vegetation Database, to obtain information about topographic site conditions and structure of B. litwinowii stands. B. litwinowii forest growth was assessed by digitizing the forest outlines from aerial and space‐borne imagery (1987, 2005 and 2010). To identify areas of B. litwinowii encroachment as an indicator for different encroachment stages, we modelled the tree and shrub cover using the Random Forest algorithm.Results
We found four types of B. litwinowii stands, characterized by different tree and shrub coverage (initial Bromus variegatus–Betula litwinowii encroachment indicating the first stage of succession, Aconitum nasutum–Betula litwinowii forest, Rubus idaeus–Betula litwinowii forest and Rhododendron caucasicum–Betula litwinowii tree line scrubs). B. litwinowii forest increased 25% compared to 1987 mainly in an uphill direction. Furthermore the modelled tree and shrub cover (R2 = .69) could be related to the four vegetation types.Conclusions
Our results indicate a recent trend towards shrub encroachment and consequently reforestation in the Kazbegi region. 相似文献2.
Gortazar C Torres MJ Acevedo P Aznar J Negro JJ de la Fuente J Vicente J 《BMC microbiology》2011,11(1):27
Background
We describe the diversity of two kinds of mycobacteria isolates, environmental mycobacteria and Mycobacterium bovis collected from wild boar, fallow deer, red deer and cattle in Do?ana National Park (DNP, Spain), analyzing their association with temporal, spatial and environmental factors. 相似文献3.
Goang-Won Cho Seung Min Shin Hyun Kee Kim Seon-Ah Ha Sanghee Kim Joo-Hee Yoon Soo Young Hur Tae Eung Kim Jin Woo Kim 《BMC cell biology》2007,8(1):50
Background
The Human cervical cancer oncogene (HCCR-1) has been isolated as a human oncoprotein, and has shown strong tumorigenic features. Its potential role in tumorigenesis may result from a negative regulation of the p53 tumor suppressor gene. 相似文献4.
Diagnostic polymorphisms in the mitochondrial cytochrome b gene allow discrimination between cattle,sheep, goat,roe buck and deer by PCR-RFLP 总被引:3,自引:0,他引:3
Background
As an alternative to direct DNA sequencing of PCR products, random PCR-RFLP is an efficient technique to discriminate between species. The PCR-RFLP-method is an inexpensive tool in forensic science, even if the template is degraded or contains only traces of DNA from various species. 相似文献5.
Background
For large-scale biological networks represented as signed graphs, the index of frustration measures how far a network is from a monotone system, i.e., how incoherently the system responds to perturbations. 相似文献6.
Michal Amir Shabtai Romano Shlomit Goldman Eliezer Shalev 《Reproductive biology and endocrinology : RB&E》2009,7(1):152-8
Background
To study the expression of Plexin-B1, Glycodelin, and MMP7 during the menstrual cycle in the endometrium and in the fallopian tube. 相似文献7.
Background
Inhibitor of Apoptosis (IAP) proteins are key intrinsic regulators of apoptosis induced by a variety of triggers. We isolated the rat Inhibitor of Apoptosis genes 1, 2 and 3 and characterized their tissue distribution and expression. 相似文献8.
Thaís B. Guedes Ricardo J. Sawaya Alexander Zizka Shawn Laffan Søren Faurby R. Alexander Pyron Renato S. Bérnils Martin Jansen Paulo Passos Ana L. C. Prudente Diego F. Cisneros‐Heredia Henrique B. Braz Cristiano de C. Nogueira Alexandre Antonelli 《Global Ecology and Biogeography》2018,27(1):14-21
Motivation
We generated a novel database of Neotropical snakes (one of the world's richest herpetofauna) combining the most comprehensive, manually compiled distribution dataset with publicly available data. We assess, for the first time, the diversity patterns for all Neotropical snakes as well as sampling density and sampling biases.Main types of variables contained
We compiled three databases of species occurrences: a dataset downloaded from the Global Biodiversity Information Facility (GBIF), a verified dataset built through taxonomic work and specialized literature, and a combined dataset comprising a cleaned version of the GBIF dataset merged with the verified dataset.Spatial location and grain
Neotropics, Behrmann projection equivalent to 1° × 1°.Time period
Specimens housed in museums during the last 150 years.Major taxa studied
Squamata: Serpentes.Software format
Geographical information system (GIS).Results
The combined dataset provides the most comprehensive distribution database for Neotropical snakes to date. It contains 147,515 records for 886 species across 12 families, representing 74% of all species of snakes, spanning 27 countries in the Americas. Species richness and phylogenetic diversity show overall similar patterns. Amazonia is the least sampled Neotropical region, whereas most well‐sampled sites are located near large universities and scientific collections. We provide a list and updated maps of geographical distribution of all snake species surveyed.Main conclusions
The biodiversity metrics of Neotropical snakes reflect patterns previously documented for other vertebrates, suggesting that similar factors may determine the diversity of both ectothermic and endothermic animals. We suggest conservation strategies for high‐diversity areas and sampling efforts be directed towards Amazonia and poorly known species. 相似文献9.
Background
Gene expression signatures are typically identified by correlating gene expression patterns to a disease phenotype of interest. However, individual gene-based signatures usually suffer from low reproducibility and interpretability. 相似文献10.
Ziad W Jaradat Qotaiba O Ababneh Ismail M Saadoun Nawal A Samara Abrar M Rashdan 《BMC microbiology》2009,9(1):225
Background
Cronobacter spp. (formerly Enterobacter sakazakii), are a group of Gram-negative pathogens that have been implicated as causative agents of meningitis and necrotizing enterocolitis in infants. The pathogens are linked to infant formula; however, they have also been isolated from a wide range of foods and environmental samples. 相似文献11.
Severe teratozoospermia and its influence on pronuclear morphology,embryonic cleavage and compaction
Dara S Berger Faten AbdelHafez Helena Russell James Goldfarb Nina Desai 《Reproductive biology and endocrinology : RB&E》2011,9(1):37
Background
Fertilization, cell division and embryo development depend on genomic contributions from male and female gametes. We hypothesize that teratozoospermic sperm influences early embryo development and embryo compaction. 相似文献12.
Iraldo Bello-Rivero Yeny Torrez-Ruiz Elizabeth Blanco-Garcés Giselle Pentón-Rol Osmani Fernández-Batista Luís Javier-González Haydee Gerónimo-Perez Pedro López-Saura 《BMC biotechnology》2006,6(1):25-13
Background
TH1 immune response antagonism is a desirable approach to mitigate some autoimmune and inflammatory reactions during the course of several diseases where IL-2 and IFN-γ are two central players. Therefore, the neutralization of both cytokines could provide beneficial effects in patients suffering from autoimmune or inflammatory illnesses. 相似文献13.
J.K. Lutz J. Crawford A.E. Hoet J.R. Wilkins III J. Lee 《Journal of applied microbiology》2013,115(1):171-178
Aims
To evaluate the performance of four sampling methods [contact plates, electrostatic wipes (wipe), swabs and a novel roller sampler] for recovery of Staphylococcus aureus from a stainless steel surface.Methods and Results
Stainless steel test plates were inoculated with Staph. aureus, dried for 24 h and sampled using each of the four methods. Samples were either incubated directly (roller, contact plate) or processed using elution and membrane filtration (swab, wipe). Performance was assessed by calculating the apparent sampling efficiency (ASE), analytical sensitivity (Sn) and percentage of replications with positive growth. The wipe demonstrated the best performance across all inoculating concentrations (ASE48 h = 18%; Sn48 h = 7 CFU per 100 cm2). The swab performed well when corrected for area actually sampled (ASE48 h = 24%; Sn48 h = 76 CFU per 100 cm2). Of the contact‐based methods, the newly developed roller sampler outperformed the contact plate (roller: ASE48 h = 10%; Sn48 h = 17 CFU per 100 cm2; contact plate: ASE48 h = 0·04%; Sn48 h = 1412 CFU per 100 cm2); both contact samplers performed better at higher inoculating concentrations (6E3 CFU per 100 cm2 for the roller and 6E6 CFU per 100 cm2 for the contact plate). Overall, the electrostatic wipe produced the highest number of replications resulting in positive growth (74%24 h, 91%48 h).Conclusions
This study demonstrates that selection of the sampling method must be carefully considered, given that different methods have varying performance.Significance and Impact of the Study
This is the first study assessing static wipes for sampling and one that uses a more real‐world‐relevant 24‐h drying time. The results help with infection control, and environmental health professionals choose better sampling methodologies. 相似文献14.
Song Chen Jennifer S Armistead Katie N Provost-Javier Joyce M Sakamoto Jason L Rasgon 《BMC evolutionary biology》2010,10(1):142
Background
Mosquito vitellogenin (Vtg) genes belong to a small multiple gene family that encodes the major yolk protein precursors required for egg production. Multiple Vtg genes have been cloned and characterized from several mosquito species, but their origin and molecular evolution are poorly understood. 相似文献15.
16.
Dawn Doré Jonathon de Hoog Graham Giles Changhai Ding Flavia Cicuttini Graeme Jones 《Arthritis research & therapy》2012,14(1):R13-10
Introduction
Bone marrow lesions (BMLs) play an important role in knee osteoarthritis, but their etiology is not well understood. The aim of this longitudinal study was to describe the association between dietary factors, serum lipids, and BMLs. 相似文献17.
Background
Although MP20 is the second most highly expressed membrane protein in the lens its function remains an enigma. Putative functions for MP20 have recently been inferred from its assignment to the tetraspanin superfamily of integral membrane proteins. Members of this family have been shown to be involved in cellular proliferation, differentiation, migration, and adhesion. In this study, we show that MP20 associates with galectin-3, a known adhesion modulator. 相似文献18.
Background
Cyclins regulate the cell cycle in association with cyclin dependent kinases (CDKs). CDKs are under inhibitory control of cyclin dependent kinase inhibitors (CDKIs). 相似文献19.
Morphometric and morphologic parameters of the heart in healthy Alouatta guariba clamitans (Cabrera, 1940)
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Murilo Gomes de Soutello Charlier Maurício Gianfrancesco Filippi Carolina Hagy Girotto Vanessa Lanes Ribeiro Carlos Roberto Teixeira Maria Lúcia Gomes Lourenço Luiz Carlos Vulcano 《Journal of medical primatology》2018,47(1):60-66
Background
This study aimed at assessing the heart function of one neotropical primate (Alouatta guariba clamitans) kept in captivity using radiography, electrocardiogram (ECG) and Doppler echocardiography.Methods
Ten adult healthy howler monkeys (A. g. clamitans) were evaluated under general anaesthesia. Vertebral Heart Scores (VHS) were obtained from radiographic studies. Ejection fraction, shortening fraction of left ventricle, left atrial/aortic root ratio, ascending aortic diameter, peak velocity of pulmonary, mitral, tricuspid and aortic blood flow and other values were measured by Doppler echocardiography. Heart rate, mean electrical axis of QRS complex, P, Q, R, S, T amplitude, P, PR interval, QRS, QT interval duration and ST segment unbalancing were measured by ECG.Results and conclusions
Exam techniques were akin the ones used in humans. Doppler echocardiographic, radiographic, electrocardiographic and clinical parameters for howler monkey were described and correlated. The results have shown profiles of cardiovascular function and structure of A. g. clamitans. 相似文献20.
Adi Kozminsky-Atias Adi Bar-Shalom Dan Mishmar Noam Zilberberg 《BMC evolutionary biology》2008,8(1):333