Recent researches suggest that functional diversity represents the response of communities to environmental alterations better than taxonomic diversity. However, there is scarce information about how the functional diversity of freshwater fishes is affected by habitat type and the dominance of non-native species. To address this question, we analysed a large database containing 15 morpho-functional traits of 61 fish species from the Pannon Biogeographic region (Hungary). Based on a fish faunistic list and relative abundance of taxa, we quantified the taxonomic and functional diversity of riverine communities for?>?700 sites of six habitat types. We asked how non-native fishes affected the taxonomic and functional diversity in different river types and at the local scale (i.e. at the site level), and how the diversity measures of native fauna elements changes along the invasion gradient. Our results showed that both functional and taxonomic richness increases with habitat complexity, from small headwater streams to large rivers. Therefore taxonomic diversity served as a good proxy for functional diversity along the environmental gradient of river types. Non-natives showed considerable functional diversity relative to their species number in each habitat type. Diversity values of native fauna elements initially increased, and then showed a major decrease along the invasion gradient. River type-specific evaluations highlighted the importance of considering the proliferation of invasive species based on both taxonomic and functional diversity indices. We argue that type-specific action plans are needed in conservation management to preserve the taxonomic and functional diversity of native fishes in Hungary, but also elsewhere.
In this paper, an online self-organizing scheme for Parsimonious and Accurate Fuzzy Neural Networks (PAFNN), and a novel structure learning algorithm incorporating a pruning strategy into novel growth criteria are presented. The proposed growing procedure without pruning not only simplifies the online learning process but also facilitates the formation of a more parsimonious fuzzy neural network. By virtue of optimal parameter identification, high performance and accuracy can be obtained. The learning phase of the PAFNN involves two stages, namely structure learning and parameter learning. In structure learning, the PAFNN starts with no hidden neurons and parsimoniously generates new hidden units according to the proposed growth criteria as learning proceeds. In parameter learning, parameters in premises and consequents of fuzzy rules, regardless of whether they are newly created or already in existence, are updated by the extended Kalman filter (EKF) method and the linear least squares (LLS) algorithm, respectively. This parameter adjustment paradigm enables optimization of parameters in each learning epoch so that high performance can be achieved. The effectiveness and superiority of the PAFNN paradigm are demonstrated by comparing the proposed method with state-of-the-art methods. Simulation results on various benchmark problems in the areas of function approximation, nonlinear dynamic system identification and chaotic time-series prediction demonstrate that the proposed PAFNN algorithm can achieve more parsimonious network structure, higher approximation accuracy and better generalization simultaneously. 相似文献
Osteoporosis is a common disorder, with prolongation of the average life span it has become a major public health problem. On the formation of osteoporosis genetic factors and environmental influences could play a role then it is considered as multi-factorial. Because a variety of functions to affect susceptibility to the formation of osteoporosis VDR-F, VDR-B, COL1A1, ESR1X, ESR1P and CTR are thought to be candidate genes. In this study, the aim is to investigate the relationship between these genes polymorphism and bone mineral density (BMD) values of lumbar vertebra and femoral neck in 188 Turkish people. Lumbar spine and femoral neck BMD of the individuals included in the study were measured by the dual X-ray absorptiometry method. The genotyped polymorphisms by simultaneous amplification of five regions of the genome, containing six SNPs of interest and detecting the amplified product, using the kit MetaBone Clinical Arrays?. Statistical analyses indicated that; VDR-B gene polymorphisms major (P?=?0.013), VDR-F polymorphisms have minor (P?=?0.082) effect on femur BMD. None of the other genes has any significant effect on spinal BMD. Patient age, body mass index and diet has significant effect on femoral and spinal BMD. Osteoporosis is a multi-factorial disease and many genetic and non-genetic risk factors contribute to the development of osteoporosis. Early detection of a genetic predisposition to osteoporosis should allow delay and/or limit unfavorable changes in the bone tissue. 相似文献
DNMT3B is an important enzyme to modulate the methylation status in mammalian cells. The aim of this study is to investigate the correlation of the DNMT3B G39179T polymorphism with the susceptibilities of colorectal adenomatous polyps and adenocarcinoma. This case-control study included 146 colorectal adenomatous polyps, 170 colorectal adenocarcinoma patients, and 157 normal controls. DNMT3B polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis. Family history of colorectal cancer significantly increases the risk of developing colorectal adenomatous polyps and adenocarcinoma. The genotype frequency of DNMT3B polymorphism (T/T and G/T + G/G) in adenocarcinoma patients was significantly different from that in controls (P value = 0.01). Compared with DNMT3B T/T genotype, the G allelotype (G/T + G/G genotype) had lower risk to develop colorectal adenocarcinoma (OR = 0.50, 95% CI = 0.29–0.87); while there was no significant difference between the colorectal adenomatous polyps patients and controls (OR = 0.63, 95% CI = 0.37–1.09), although descending tendency could be found in this polyps group. In the stratification analysis, a significant association was confined to subgroups of age < 55 (OR = 0.31, 95% CI = 0.12–0.84) and males (OR = 0.35, 95% CI = 0.17–0.71). Meanwhile, combined G/T + G/G genotypes were found to have a lower risk in non-drinkers to develop both colorectal adenomatous polyps and adenocarcinoma (OR = 0.54, 95% CI = 0.31–0.96 and OR = 0.48, 95% CI = 0.27–0.84, respectively). This study also showed a distinct difference in the distribution of DNMT3B G39179T SNP in different ethnics. DNMT3B G39179T SNP may be a potential genetic susceptibility factor for adenocarcinoma of the colon, especially in younger Chinese Han non-drinker men. 相似文献
Traumatic brain injury (TBI) is physical injury to brain tissue that temporarily or permanently impairs brain function.
Objectives
Evaluate the use of metabolomics for the development of biomarkers of TBI for the diagnosis and timing of injury onset.
Methods
A validated model of closed injury TBI was employed using 10 TBI mice and 8 sham operated controls. Quantitative LC–MS/MS metabolomic analysis was performed on the serum.
Results
Thirty-six (24.0 %) of 150 metabolites were altered with TBI. Principal component analysis (PCA) and Partial least squares discriminant analysis (PLS-DA) analyses revealed clear segregation between TBI versus control sera. The combination of methionine sulfoxide and the lipid PC aa C34:4 accurately diagnosed TBI, AUC (95 % CI) 0.85 (0.644–1.0). A combination of metabolite markers were highly accurate in distinguishing early (4 h post TBI) from late (24 h) TBI: AUC (95 % CI) 1.0 (1.0–1.0). Spermidine, which is known to have an antioxidant effect and which is known to be metabolically disrupted in TBI, was the most discriminating biomarker based on the variable importance ranking in projection (VIP) plot. Several important metabolic pathways were found to be disrupted including: pathways for arginine, proline, glutathione, cysteine, and sphingolipid metabolism.
Conclusion
Using serum metabolomic analysis we were able to identify novel putative serum biomarkers of TBI. They were accurate for detecting and determining the timing of TBI. In addition, pathway analysis provided important insights into the biochemical mechanisms of brain injury. Potential clinical implications for diagnosis, timing, and monitoring brain injury are discussed.
While androgens generally have been associated with an increased cardiovascular risk, recent studies indicate potential beneficial acute effects of testosterone. However, detailed evaluation of chronic and acute actions of testosterone on the function of cardiac I(Ca,L) and intracellular Ca2+ handling is limited. To clarify this situation we performed whole-cell and single-channel analysis of I(Ca,L), recordings of Ca2+ sparks, measurements of contractility and quantitative real-time RT-PCR in rat cardiomyocytes following testosterone pretreatment and acute testosterone application. Pretreatment with testosterone 100 nM for 24-30 h increased whole-cell I(Ca,L) from 3.8+/-0.8 pA/pF (n=10) to 10.1+/-0.31 pA/pF (n=9) at +10 mV (p<0.001). Increase of I(Ca,L) density was caused by both, increased expression levels of the alpha 1C subunit of L-type calcium channel and a pronounced increment of the single-channel activity (availability 81.8+/-3.15% versus 37.1+/-7.01%; open probability 12.8+/-3.09% versus 1.0+/-0.62%, p<0.01). Moreover, testosterone pretreatment significantly increased the frequency of Ca2+ sparks and improved myocytes contractility without altering SR Ca2+ load. All chronic effects could be inhibited by flutamide. In contrast acute testosterone administration significantly reduced I(Ca,L) density. Indeed, on the single-channel level acute testosterone application completely reversed the chronic testosterone-mediated effects, and antagonized the chronic testosterone effects on Ca2+ spark frequency, which was unaffected by flutamide. Thus, testosterone pretreatment activates I(Ca,L) via nuclear receptor-mediated pathways, while testosterone acutely blocks I(Ca,L) in a direct manner. Thus, testosterone chronically affects the basal level of intracellular Ca2+ handling, which in addition rapidly may be modulated by acute changes of hormone levels. 相似文献
Increasing evidence supports the hypothesis that tannic acid, a plant polyphenol, exerts anticarcinogenic activity in chemically induced cancers. In the present study, tannic acid was found to strongly inhibit tyrosine kinase activity of epidermal growth factor receptor (EGFr) in vitro (IC50 = 323 nM). In contrast, the inhibition by tannic acid of p60(c-src) tyrosine kinase (IC50 = 14 microM) and insulin receptor tyrosine kinase (IC50 = 5 microM) was much weaker. The inhibition of EGFr tyrosine kinase by tannic acid was competitive with respect to ATP and non-competitive with respect to peptide substrate. In cultured cells, growth factor-induced tyrosine phosphorylation of growth factor receptors, including EGFr, platelet-derived growth factor receptor, and basic fibroblast growth factor receptor, was inhibited by tannic acid. No inhibition of insulin-induced tyrosine phosphorylation of insulin receptor and insulin-receptor substrate-1 was observed. EGF-stimulated growth of HepG2 cells was inhibited in the presence of tannic acid. The inhibition of serine/threonine-specific protein kinases, including cAMP-dependent protein kinase, protein kinase C and mitogen-activated protein kinase, by tannic acid was only detected at relatively high concentration, IC50 being 3, 325 and 142 microM respectively. The molecular modeling study suggested that tannic acid could be docked into the ATP binding pockets of either EGFr or insulin receptor. These results demonstrate that tannic acid is an in vitro potent inhibitor of EGFr tyrosine kinase. 相似文献
We demonstrate that the controversial Parasenecio delphiniiphyllus (known from northeastern Yunnan and western Guizhou, China) is not conspecific with P. delphiniifolius (Japan) since these two species are readily distinguishable by inflorescence structure and involucre length, as well as in the length of anther tails and anther collars. The two species also have different chromosome numbers, 2n = 60 in P. delphiniiphyllus and 2n = 52 in P. delphiniifolius. Evidence from gross morphology, floral micro‐morphology, cytology and geographical distribution strongly supports the independent specific status of P. delphiniiphyllus. 相似文献