Aims: To determine whether species-rich Mediterranean heathlands, including the herriza, constitute distinct heathland formations rather than transitional vegetation units between Atlantic heathlands and Mediterranean garrigue shrublands.
Methods: We quantified species richness, endemism and analysed the β-diversity of the woody component of Mediterranean heathland communities throughout its geographic range, with special emphasis on the Strait of Gibraltar region.
Results: Mediterranean heathlands, including the herriza, are not transitional communities between Atlantic heathlands and Mediterranean shrublands. Woody species richness and, particularly, endemic richness was the highest in the herriza.
Conclusions: The high biodiversity values of the herriza are a likely consequence of the ecological singularity of the Strait of Gibraltar region and its known role as a glacial refugium. Despite its treeless feature, the herriza deserves special recognition and protection from both in its European and North African extension. 相似文献
Aims: To evaluate the effects of grazing and herbivore density on plant diversity, community composition and vegetation structure of the endemic wet heathlands dominated by Erica mackayana in Galicia.
Methods: Field sampling of vascular plants, generalised linear models (GLMs), non-metric multidimensional distance scaling (NMDS).
Results: Grazed sites had significantly higher total and rare species richness and diversity than ungrazed sites. Higher densities of cattle resulted in lower numbers of rare species, while wild pony density had no effect on rare species richness. In grazed sites, vegetation was lower with greater variation in height, resulting in greater heterogeneity of the habitat. Precipitation and summer temperatures were related to plant diversity, mainly beta diversity. Soil organic matter negatively correlated with rare species.
Discussion: Grazing, mostly by wild ponies, was demonstrated to be positively related to plant diversity and vegetation structure. Lack of grazing or high cattle densities resulted in a negative effect on total and rare species richness and diversity. Future climate change may negatively affect heathland plant diversity. Galician wild ponies represent a unique case of sustainable management of a wild species and an invaluable cultural heritage. Moreover, they have a significant role in maintaining the endemic E. mackayana heathlands, what would justify specific conservation actions for these large herbivores. 相似文献
Aims: To assess responses of breeding birds to moorland management over a 14-year period.
Methods: Vegetation and birds were surveyed at 2–3-year intervals and changes examined in relation to sheep and cattle grazing, vegetation burning and cutting.
Results: Seven correlations between change in management and change in bird abundance were detected, and six between change in vegetation and change in bird abundance. On plots where sheep numbers declined, Golden Plover Pluvialis apricaria and Northern Wheatear Oenanthe oenanthe declined. Where a greater area was burned, Golden Plover increased in the initial post-burning period but Red Grouse Lagopus lagopus scotica declined. Eurasian Curlew Numenius arquata and Sky Lark Alauda arvensis increased where a greater area of moorland vegetation was cut. Whinchat Saxicola rubetra declined with increasing cattle numbers on a plot.
Conclusions: Bird populations respond to changes in moorland management, but these changes are not always associated with detectable changes in vegetation. These responses of moorland breeding birds to management could help refine agri-environment options and other conservation interventions on moorland. Responses differed between bird species, ideally requiring site-specific planning where managing for multiple species is a goal. 相似文献
Aims: To explore the vulnerability of these transitional forests to changes in land use and climate, we evaluated the effects of fragmentation and climatic variables on forest structure.
Methods: We measured the diameter and height of 14,185 trees with diameter ≥10 cm at 24 forest plots distributed over an area of 25,000 km2. For each plot, we obtained data on contemporary fragmentation and climatic variables.
Results: Forest structure variables (height, diameter, height:diameter allometry, biomass) varied significantly both within and among plots. The height, H:D and biomass of trees were positively correlated with annual precipitation and fragment area.
Conclusions: The association between forest structure and precipitation indicates that these forests plots are likely to be vulnerable to dry season intensification anticipated for the southern edge of the Amazon. Additionally, the reduction in the fragment area may contribute to reductions in forest biomass and tree height, and consequently ecosystem carbon stocks. Given the likely susceptibility of these forests, urgent conservation action is needed to prevent further habitat degradation. 相似文献
Objective: To asses the association of Guanine nucleotide-binding protein (GNB3) (C825T) gene's polymorphism with T2DM.
Materials and methods: A case–control study including 400 North Indians was performed using Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP) approach to analyze genetic polymorphism.
Results: No significant difference was observed in genotype and allele frequencies of GNB3 gene on comparing cases with controls.
Discussion: Our study is in agreement with studies on Polish, Japanese, Hispanic-American and Danish populations who observed no significant association between GNB3 (C825T) polymorphism and T2DM.
Conclusion: GNB3 (C825T) polymorphism is not associated with T2DM. 相似文献
Objective: The objective of this study is to investigate the association between sleep-disordered breathing (SDB) – a source of oxidative stress – and CML.
Materials and methods: About 1002 participants in the Cardiovascular Health Study (CHS) were studied.
Results: Women with SDB had significantly higher CML concentration compared with those without SDB (OR?=?1.63, 95%CI?=?1.03–2.58, p?=?0.04). The association was not significant among men.
Discussion: SDB was associated with CML concentration among elderly women but not men in the Cardiovascular Health Study.
Conclusion: Accumulation of CML may be an adverse health consequence of SDB 相似文献
Aims: To determine differences in diversity patterns between serpentine and non-serpentine communities.
Methods: A two-year study was conducted in native eastern Mediterranean grasslands. For each year 40 0.25 m2 plots were sampled across four pairs of sites, each of which contained a serpentine and an adjacent non-serpentine plant community. Alpha and beta diversity (variation in species composition among plots within localities), species composition and biomass production were determined. Total soil elemental concentrations and pH were also measured.
Results: Serpentine habitats were shown to support a lower alpha diversity relative to non-serpentine habitatas on a per plot basis. Differences in alpha diversity between the two substrates were associated with variation in soil chemistry rather than above-ground biomass production. Serpentine habitats also exhibited lower beta diversity, which was unrelated to variation in biomass production. The two contrasting communities presented distinct species composition.
Conclusions: Differences in diversity patterns between serpentine and non-serpentine communities in the eastern Mediterranean are influenced by soil chemistry rather than biomass production. 相似文献
Objectives: Few studies have compared the expression of inflammatory or adhesion molecules between coronary artery disease (CAD) versus CSX.
Materials and methods: Ninety-two CSX and 145 CAD subjects without known diabetes mellitus underwent coronary angiogram for angina.
Results: Vascular cell adhesion molecule (VCAM)-1 (median, 507 versus 431?ng/ml, p?=?0.001) was significantly higher in the CAD group. In the binary regression, VCAM-1 was a significant differential factor for CAD versus CSX.
Discussion and conclusion: Adhesion molecules might be implicated in the differential expression of macro versus microvascular coronary disease.
Trial registration number: NCT01198730 at https://clinicaltrials.gov 相似文献
Aims: To explore which factors have more importance in determining the pre-fledging daily survival rates in a Yellow-legged Gull population from northern Iberia. Specifically, we tested for the effect of hatching date and order, body size and condition and meteorological conditions on pre-fledging survival.
Methods: Cormack–Jolly–Seber models with mixtures were used to model daily survival rates.
Results: Daily survival rates were mostly negatively affected by hatching date.
Conclusions: Hatching date was the most important factor affecting survival of chicks during the pre-fledging period in a Yellow-legged Gull colony from northern Iberia. 相似文献
Objective: The study examined the early release kinetics of TnTuORF.
Materials and methods: We analyzed the time course of the release of cardiac troponins I and T and TnTuORF in patients (n?=?31) with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy (TASH).
Results: Fifteen minutes after TASH, the levels of both troponins increased significantly (cTnT median: 18?ng/L versus 27?ng/L; cTnI median: 15?ng/L versus 25?ng/L). TnTuORF showed no variation.
Discussion: We observed a significantly greater increase in cTnI compared with cTnT.
Conclusion: Our results demonstrate that troponin assays allow early detection of myocardial injury, whereas TnTuORF levels remain unchanged in this setting. 相似文献
Objective: The aim of this study is to assess the prognostic value of leptin in patients with proven coronary artery disease (CAD) (N?=?1907).
Methods: AtheroGene is a contemporary CAD cohort study (N?=?3229). Median follow-up time was 3.8 (Quartile 1/3 with 2.8/4.9) years.
Results: Leptin concentration was associated with a hazard ratio (HR) for the fully adjusted model of HR?=?1.32 in women but was not significant in men. The endpoint cardiovascular death and non-fatal myocardial infarction was observed in 167 patients.
Conclusion: In women with known CAD, increased leptin concentration is useful for predicting cardiovascular death and non-fatal myocardial infarction. 相似文献
Objective: To investigate whether polymorphisms in IL21 gene contribute to sepsis susceptibility.
Materials and methods: Three single-nucleotide polymorphisms of IL21 (rs907715, rs2055979, rs12508721) were genotyped by TaqMan assay in patients with sepsis and control subjects.
Results: Polymorphisms rs2055979 and rs12508721 in IL21 were more frequent in sepsis patients compared to general population. But allele frequency of rs907715 was not significantly different between sepsis patients and control subjects.
Conclusion: Polymorphisms in IL21 may be associated with sepsis risk. 相似文献
Objective: To evaluate H19 RNA in urine cells as diagnostic tool for UC.
Materials and methods: RT-PCR analysis of urine samples from healthy volunteers and UC patients.
Results: H19 RNA was unequivocally detected in the urine of 90.5% of patients and 25.9% of controls. H19 copies were three orders of magnitude higher in patients. Receiver operating characteristic analysis showed an area under the curve of 0.933.
Conclusions: This pilot study shows that urinary cell H19 is a highly sensitive test for UC and pending verification could transform patient management. 相似文献
Objective: To assess oral riboflavin is an adherence marker.
Methods: Riboflavin was incorporated into active treatment and placebo pills for a clinical trial lasting for 2 years.
Results: The accuracy (area under the receiver operating curve) of urinary riboflavin was 0.91 as a binary classifier of adherence, and was similar or better than for two active study ingredients daidzein (0.92) and genistein (0.87) (all p?<?0.0001). Decreased adherence over time was similar in the two study groups.
Conclusion: Riboflavin is an accurate and useful biomarker for study pill ingestion. 相似文献
Objective: This review aimed to highlight biomarker characterisation and assessment of unique bacterial pili.
Methods: A PubMed search for bacterial pili, diagnostics, vaccine and therapeutics was performed, with emphasis on the well characterised pili.
Results: In total, 46 papers were identified and reviewed.
Conclusion: Extensive analyses of pili enabled by advanced nanotechnology and whole genome sequencing provide evidence that they are strong biomarker candidates. Mycobacterium tuberculosis curli pili are emphasised as important epitopes for the development of much needed point-of-care diagnostics and therapeutics. 相似文献
Aims: To quantify observer error in population estimation of the rare plant species Physaria filiformis in Missouri, USA.
Methods: The abundance of P. filiformis was estimated within 25-m2 plots by six trained observers with varying experience levels over 10 years. Observers assigned plots to six predefined density classes. A total of 477 plots were estimated annually, and actual counts were conducted on ca. 10% of the plots to assess per cent agreement of estimates with counts.
Results: Over a third of the estimates of plant abundance evaluated for accuracy (36.4%) deviated from exhaustive counts. The majority of the misestimates were underestimates by one density class (29.4%). The number and type of misestimates varied systematically with density class.
Conclusions: Observer error could be explained to some degree by variation in population density, but not by experience. It appears that inherent differences exist among observers that cannot be entirely compensated for by experience or training. Observer error in this system represents a systematic bias, and can be compensated for by use of correction factors, which would ideally be both density class-dependent and observer-specific. 相似文献
Aims: The aim of this work was to investigate the effects of dispersal limitation and environmental filtering on tree recruitment. To accomplish this, we employed the unified neutral theory of biodiversity and biogeography to examine migration within the metacommunity, defined as a set of interacting local communities linked by the dispersal of multiple potentially interacting species.
Methods: We sampled 12,975 individuals with dbh ≥ 1 cm in 26 1-ha permanent plots, including habitats of terra firme, transitional forests, várzea and campinarana, on the upper Madeira River, Brazilian Amazon.
Results: Campinarana drew individuals from outside the metacommunity species pool at a mean probability of recruitment of 0.06, a much lower probability than terra firme (0.31), transitional (0.21) and várzea forests (0.22). Environmental variables, such as water table depth, soil texture and fertility, were related to differences in community assembly.
Conclusions: Species abundance distribution and diversity patterns of plant assemblages in a large river landscape in the Amazon highlight the importance of environmental heterogeneity that conditions beta-diversity. The high variation in recruitment probabilities from the metacommunity species pool to local communities suggests high habitat variability in the process of maintaining patterns of local diversity. 相似文献
Aim: To test the hypothesis that the epiphytic lichen diversity at the forest edges was reduced compared with that in the forest interior, and to analyse lichen diversity in comparison with the more highly elevated and more continental Mongolian Altai.
Methods: Six plots each in the interior and the edge with a total of 240 Larix sibirica trees were studied in the Katon-Karagai National Park, East Kazakhstan.
Results: Species richness and evenness at the tree level were higher in the interior than at the edge. The epiphytic lichen diversity in the forest interior was similar in the Kazakh and Mongolian Altai, whereas that at the forest edge was lower in the Mongolian Altai.
Conclusions: Strong degradation of the forest edges in the Kazakh Altai is the probable cause of the reduced epiphytic lichen diversity compared with the interior. The similar species richness in the forest interiors of the Kazakh and Mongolian Altai suggests that the differences at the forest edge are probably, at least partly, due to different land-use regimes and not to differences in macroclimate. 相似文献
Aim: To test whether revegetation of ski-pistes in open habitat areas results in bird community recovery.
Methods: The bird communities in two ski resorts in the Italian Maritime Alps were surveyed using a standardized area count method in three different plot types: non-restored ski-pistes (newly constructed), restored ski-pistes and control plots in grassland far from ski-pistes.
Results: In 49 independent plots, 32 species were recorded. Species richness and abundance of birds were significantly higher on restored than on non-restored ski-pistes, independently of the species group considered and the analyses carried out. Bird community parameters of restored ski-pistes were still lower than those of natural grassland, as shown by results of typical grassland species.
Conclusion: Our results suggest that an apparently successful restoration of ski-pistes may be not enough to promote a complete recovery of bird communities. The complete recovery of local bird communities may be promoted only if an integral recovery of the original vegetal communities is achieved. We suggest the best conservation option is to adopt techniques to maintain as far as possible original grassland if construction of new ski-pistes is unavoidable. 相似文献
Objective: To review the evidence and investigate the association between immune-inflammatory biomarkers and CE strokes versus other stroke subtypes.
Methods: We systematically reviewed the literature (sources: MEDLINE, web-based register http://stroke-biomarkers.com, reference lists) with quality assessment and meta-analysis of selected articles.
Results: The most consistent association was found between C-reactive protein (CRP) and CE strokes when compared to other stroke subtypes (standardized mean difference 0.223 (0.116, 0.343); p?<?0.001)
Conclusions: Our findings confirm a possible association between selected inflammatory biomarkers and CE stroke. 相似文献