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1.
We describe a trainable system for analyzing videos of developing C. elegans embryos. The system automatically detects, segments, and locates cells and nuclei in microscopic images. The system was designed as the central component of a fully automated phenotyping system. The system contains three modules 1) a convolutional network trained to classify each pixel into five categories: cell wall, cytoplasm, nucleus membrane, nucleus, outside medium; 2) an energy-based model, which cleans up the output of the convolutional network by learning local consistency constraints that must be satisfied by label images; 3) a set of elastic models of the embryo at various stages of development that are matched to the label images.  相似文献   
2.
The reversal of humic matter-induced inhibition of callus growth and metabolism by 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in Pinus laricio. Two forest humic fractions (relative molecular mass (Mr) > 3500), derived from soil under Fagus sylvatica (Fs) and Abies alba (Aa) plantation, were used. Pinus laricio callus was grown for a subculture period (4 weeks) on Basal Murashige and Skoog (MS) medium plus forest humic matters (Fs or Aa), at a concentration of 1 mg C/l, and then was transferred, for an additional four weeks, to a MS medium culture without humic matter, but with different hormones: indole-3-acetic acid (IAA, 2 mg/1) or 2,4-dichlorophenoxyacetic acid (2,4-D, 0.5 mg/1) and/or 6-benzylaminopurine (BAP, 0.25 mg/1). Growth of calluse, glucose, fructose, and sucrose contents, and activities of soluble and bound invertases, glucokinase, phosphoglucose isomerase, aldolase, and pyruvate kinase were monitored. The results show a negative effect of humic fractions on callus growth, due to decreased utilization of glucose and fructose, and decreased activities of glycolytic enzymes. The effects are reversible. Substitution of humic fractions with 2,4-D+BAP or 2,4-D is followed by an increase of glycolytic enzyme activities and, consequently, by the utilization of glucose and fructose that induces a restart of growth. In contrast, the inhibitory effects of humic fractions persist when they are substituted with BAP alone, indicating that only the auxin 2,4-D is capable of reversing the negative effects. A possible competitive action on the auxin-binding site between 2,4-D and the chemical structures in the forest humic fractions is suggested.  相似文献   
3.
Droughts are affecting an increasing number of lotic ecosystems worldwide due to the combined effects of climatic and anthropogenic pressures. Unlike naturally intermittent rivers, where the drying phase is a part of the annual flow regime, water scarcity in Alpine rivers represents a relatively recent phenomenon and, therefore, a major threat for the biodiversity of these lotic ecosystems. However, Alpine stream community response to drought is still poorly investigated. Here, we assess the recovery of macroinvertebrates in two Alpine streams after a supraseasonal drought. As water returned, a total of 10 sampling sessions were carried out, and temporal patterns in diversity, density, and taxonomic composition of benthic communities, as well as in the percentage of functional feeding groups, were investigated. We found that the resistance of invertebrate communities in Alpine streams is generally low: drought markedly reduced the diversity and density of macroinvertebrates. Conversely, our results suggest that the passive dispersal by drift from the upstream river sections seems the most probable mechanism promoting the post‐drought recovery. Nevertheless, this resilience ability appears to be stream specific and influenced by intrinsic stream characteristics, including the flow permanence and distance from the nearest upstream perennial reach. This work sheds light on the ecological consequences of droughts on macroinvertebrate communities. As flow intermittency in Alpine areas is expected to intensify under current global change scenarios, results of this study provide important information to predict changes in the taxonomic composition and diversity of macroinvertebrate communities.  相似文献   
4.
The Farwell and Donchin P300 speller interface is one of the most widely used brain-computer interface (BCI) paradigms for writing text. Recent studies have shown that the recognition accuracy of the P300 speller decreases significantly when eye movement is impaired. This report introduces the GeoSpell interface (Geometric Speller), which implements a stimulation framework for a P300-based BCI that has been optimised for operation in covert visual attention. We compared the Geospell with the P300 speller interface under overt attention conditions with regard to effectiveness, efficiency and user satisfaction. Ten healthy subjects participated in the study. The performance of the GeoSpell interface in covert attention was comparable with that of the P300 speller in overt attention. As expected, the effectiveness of the spelling decreased with the new interface in covert attention. The NASA task load index (TLX) for workload assessment did not differ significantly between the two modalities. PRACTITIONER SUMMARY: This study introduces and evaluates a gaze-independent, P300-based brain-computer interface, the efficacy and user satisfaction of which were comparable with those off the classical P300 speller. Despite a decrease in effectiveness due to the use of covert attention, the performance of the GeoSpell far exceeded the threshold of accuracy with regard to effective spelling.  相似文献   
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项目地点:美国加州项目类型:建筑(教育)开工日期:2005年9月该项目综合考虑了可持续性和建筑方面的因素,并将其纳入大型公共建筑之中。该项目获2005年豪瑞可持续建筑大奖赛北美地区银奖  相似文献   
7.
The aim of this study was to assess the presence of Chlamydia pneumoniae antibodies in patients with angiographically verified atherosclerotic coronary artery disease. A total of 114 consecutive patients were investigated between April 1995 and June 1996. Patients were divided into two groups: 72 patients with acute myocardial infarction (AMI; 53 men, 19 women, mean age 62.27 +/- 10.1 years), and 42 patients with chronic ischemic heart disease (CAD; 37 men, 5 women, mean age 62.75 +/- 9.2 years). A control group of 50 normal subjects matched for age (mean 62 +/- 9 years), sex, social status and geographical area was used. Identification of Chlamydia pneumoniae was carried out with the microimmunofluorescence method, on two serum samples taken from patients on admission and after 15 days. The IgM, IgG and IgA anti-Chlamydia pneumoniae titers were assessed, values > or = 1:16, > or = 1:32 and > or = 1:8 being respectively considered positive. Acute (IgM > or = 16 or four fold rise of IgG titer) and chronic (IgG > or = 128 e IgA > or = 32 or only elevated IgA titer) infections were analyzed. IgM antibodies were not found in AMI, CAD and control groups. IgG positivity (IgG > or = 32) was found in 38% of the control group, in 58.3% of the AMI group (p < 0.05) and 42.8% of the CAD group (p < 0.01). IgA positivity > or = 8) was found in 22% of the control group, in 31.9% of the AMI group (NS) and in 33.3% of the CAD group (p < or = 0.05). Acute infection was observed in 5.5% of AMI patients and in 12% of CAD patients (NS), whereas no subject of the control group showed these values. Chronic infection was observed in 9.7% of AMI patients and in 16.6% of CAD patients (NS) whereas nobody of the control group showed these values. In conclusion, our results suggest that Chlamydia pneumoniae infection is present only in the AMI and CAD groups. It is possible to suppose that this infection may be linked to atherosclerosis through an endothelial damage or a systemic endogenous procoagulant and inflammatory activity.  相似文献   
8.
Reviews outcomes and methodological soundness of studies of hypnosis in the treatment of skin disorders, headaches, and asthma. Some studies focused on changing physiological functions, others on increasing insight in their patients, and others on altering patients' perceptions of their symptoms. Methodological weaknesses included lack of control groups, nonrandom assignment of patients to treatment conditions, and confounding of treatment effects or lack of control for placebo effects. Additional weaknesses centered around the use of single outcome measures and the failure to assess the specific roles of mediating variables. Most studies showed positive treatment effects. However, there was equivocal evidence that hypnosis can directly influence autonomic functioning. Hypnosis may be valuable in facilitating one's capacity to gain insight into how one's symptoms developed and are maintained. In addition, hypnotic procedures have resulted in some success when used to indirectly alleviate symptoms by altering how individuals perceive their disorders and how these disorders affect their lives. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
The ecological impact of fine sediments is one of the major causes of ecological degradation affecting lotic systems. Interestingly, many studies have investigated the impact of increased sediment loads on specific compartments of the lotic system, but little or no information is available about the overall impact of sedimentation. Aim of this paper was to analyse the influence of fine sedimentation on allochthonous and autochthonous energy inputs and on the structural and functional characteristics of diatom and macroinvertebrate communities. Data were collected in two Alpine streams in NW Italy, one interested by the presence of an intense mining area and the other pristine, used as a control. The two rivers greatly differed in terms of suspended solids and bed load characteristics. From 10 stations, we analysed main physico‐chemical characteristics, fine sediment indicators (using 60 sediment traps), coarse particulate organic matter (CPOM) and photosynthetic pigments amounts, taxonomic and functional characteristics of macroinvertebrate communities. We tested several causal models via path analysis. Functional traits seem to better reflect the integrated impact originating from quarries in the river basin than traditional community metrics like total abundance and specific richness. This outcome was enforced through the co‐inertia analysis, which took in consideration also metrics based on diatom communities. Our study yielded quantitative relations between sediment loads induced by quarrying activities and the degree of biological impairment and suggests which metrics are more suitable to assess this specific impact. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
10.
Protein Expression Changes in Maize Roots in Response to Humic Substances   总被引:1,自引:0,他引:1  
Humic substances are known to affect plant metabolism at different levels. We characterized humic substances extracted from earthworm feces by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and used them to treat corn, Zea mays L., seedlings to investigate changes in patterns of root protein expression. After root plasma membrane extraction and purification, proteins were separated by two-dimensional gel electrophoresis, and differential spot intensities were evaluated by image analysis. Finally, 42 differentially expressed proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The majority of them were downregulated by the treatment with humic substances. The proteins identified included malate dehydrogenase, ATPases, cytoskeleton proteins, and different enzymes belonging to the glycolytic/gluconeogenic pathways and sucrose metabolism. The identification of factors involved in plant responses to humic substances may improve our understanding of plant-soil cross-talk, and enable a better management of soil resources.  相似文献   
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