Background: Large areas of heathland landscapes in Galicia, north-west Spain, have traditionally been extensively grazed by free-ranging cattle and wild ponies. Recently, a large reduction in the number of these larger herbivores has been observed, with unknown consequences for the habitat.
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
An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light‐Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System.
As the largest CO2 emitter in the world, China has faced great pressure to mitigate its CO2 emissions. Thus, issues related to CO2 emissions in China have been widely studied. However, the industrial linkages of CO2 emissions at the regional level have been less concerned. This study integrates hypothetical extraction method with the multi-regional input–output model, and investigates industrial CO2 emission linkages of China at the regional level. Based on the data of China in 2007, which decomposes China into eight regions, this study first analyzes the production-based emission (PBE) and consumption-based emission (CBE) of each region. The PBE and CBE of 10 branches are then analyzed and decomposed into three parts. Finally, this study decomposes the externally produced embodied emission (EPEE) and internally produced embodied emission (IPEE) of Petrochemicals and Minerals in the East Coast, to illustrate how these two indicators of a branch affect other branches in the economy. Results show that regions with large PBE, such as coastal regions and Central, usually have large CBE, whereas Jing-jin has the smallest PBE and CBE. Branches such as Mining and Petrochemicals and Minerals, have large PBE and are net CO2 emission exporters; while Construction and Other Services are net importers. According to the decomposition results of PBE and CBE, branches can be classified into four groups. The decomposed IPEE and EPEE of Petrochemicals and Minerals in the East Coast show that from the perspective of regions, CO2 emissions this branch exports to and imports from East Coast are most. From the perspective of branches, decomposition of IPEE shows that Petrochemicals and Minerals in the East Coast exports a large amount of CO2 emissions to Construction, while the decomposition results of EPEE show that the studied branch imports least CO2 emissions from Construction. Policy implications deduced from this study are discussed. 相似文献
Recent studies have demonstrated that cell cycle plays a central role in development and carcinogenesis. Thus, the use of big databases and genome-wide high-throughput data to unravel the genetic and epigenetic mechanisms underlying cell cycle progression in stem cells and cancer cells is a matter of considerable interest.
Real genetic-and-epigenetic cell cycle networks (GECNs) of embryonic stem cells (ESCs) and HeLa cancer cells were constructed by applying system modeling, system identification, and big database mining to genome-wide next-generation sequencing data. Real GECNs were then reduced to core GECNs of HeLa cells and ESCs by applying principal genome-wide network projection. In this study, we investigated potential carcinogenic and stemness mechanisms for systems cancer drug design by identifying common core and specific GECNs between HeLa cells and ESCs. Integrating drug database information with the specific GECNs of HeLa cells could lead to identification of multiple drugs for cervical cancer treatment with minimal side-effects on the genes in the common core. We found that dysregulation of miR-29C, miR-34A, miR-98, and miR-215; and methylation of ANKRD1, ARID5B, CDCA2, PIF1, STAMBPL1, TROAP, ZNF165, and HIST1H2AJ in HeLa cells could result in cell proliferation and anti-apoptosis through NFκB, TGF-β, and PI3K pathways. We also identified 3 drugs, methotrexate, quercetin, and mimosine, which repressed the activated cell cycle genes, ARID5B, STK17B, and CCL2, in HeLa cells with minimal side-effects. 相似文献
Laboratory experiments were performed to determine the sampling rates of pesticides for the polar organic chemical integrative samplers (POCIS) used in Japan. The concentrations of pesticides in aquatic environments were estimated from the accumulated amounts of pesticide on POCIS, and the effect of water temperature on the pesticide sampling rates was evaluated. The sampling rates of 48 pesticides at 18, 24, and 30 °C were obtained, and this study confirmed that increasing trend of sampling rates was resulted with increasing water temperature for many pesticides. 相似文献
Orthodontic tooth movement (OTM) is an adaptive biomechanical response of dentoalveolar components to orthodontic forces, in which remodeling of the alveolar bone occurs in response to changes in the surrounding mechanical environment. In this study, we developed a framework for OTM simulation by combining an image-based voxel finite element method, with a surface-tracking level set method using three-dimensional computer models. For a case study to demonstrate its capability of expressing clinical tooth movement, we observed displacement and rotation of the tooth under three types of force conditions. The simulation results demonstrate that the proposed simulation method has the potential to predict clinical OTM. 相似文献
We propose a novel parallel computing framework for a nonlinear finite element method (FEM)-based cell model and apply it to simulate avascular tumor growth. We derive computation formulas to simplify the simulation and design the basic algorithms. With the increment of the proliferation generations of tumor cells, the FEM elements may become larger and more distorted. Then, we describe a remesh and refinement processing of the distorted or over large finite elements and the parallel implementation based on Message Passing Interface to improve the accuracy and efficiency of the simulation. We demonstrate the feasibility and effectiveness of the FEM model and the parallelization methods in simulations of early tumor growth. 相似文献