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1.
Hu Z  Liu H  Weng X  Northoff G 《PloS one》2012,7(2):e31983

Objective

Patients with major depressive disorder (MDD) clinically exhibit a deficit in positive emotional processing and are often distracted by especially negative emotional stimuli. Such emotional-cognitive interference in turn hampers the cognitive abilities of patients in their ongoing task. While the psychological correlates of such emotional conflict have been well identified in healthy subjects, possible alterations of emotional conflict in depressed patients remain to be investigated. We conducted an exploratory psychological study to investigate emotional conflict in MDD. We also distinguished depression-related stimuli from negative stimuli in order to check whether the depression-related distractors will induce enhanced conflict in MDD.

Methods

A typical word-face Stroop paradigm was adopted. In order to account for valence-specificities in MDD, we included positive and general negative as well as depression-related words in the study.

Results

MDD patients demonstrated a specific pattern of emotional conflict clearly distinguishable from the healthy control group. In MDD, the positive distractor words did not significantly interrupt the processing of the negative target faces, while they did in healthy subjects. On the other hand, the depression-related distractor words induced significant emotional conflict to the positive target faces in MDD patients but not in the healthy control group.

Conclusion

Our findings demonstrated for the first time an altered valence-specific pattern in emotional conflict in MDD patients. The study sheds a novel and specific light on the affective mechanisms underlying the abnormal emotional-cognitive interference in MDD. Such emotional conflict bears important clinical relevance since it may trigger the widespread cognitive dysfunctions frequently observed in MDD. The present findings may have important clinical implications in both prediction and psychotherapy of MDD.  相似文献   

2.
The phylogenetic relationships of multiple enterobacterial species were reconstructed based on 16S rDNA gene sequences to evaluate the robustness of this housekeeping gene in the taxonomic placement of the enteric plant pathogens Erwinia, Brenneria, Pectobacterium, and Pantoea. Four data sets were compiled, two of which consisted of previously published data. The data sets were designed in order to evaluate how 16S rDNA gene phylogenies are affected by the use of different plant pathogen accessions and varying numbers of animal pathogen and outgroup sequences. DNA data matrices were analyzed using maximum likelihood (ML) algorithms, and character support was determined by ML bootstrap and Bayesian analyses. As additional animal pathogen sequences were added to the phylogenetic analyses, taxon placement changed. Further, the phylogenies varied in their placement of the plant pathogen species, and only the genus Pantoea was monophyletic in all four trees. Finally, bootstrap and Bayesian support values were low for most of the nodes, and all nonterminal branches collapsed in strict consensus trees. Inspection of 16S rDNA nucleotide alignments revealed several highly variable blocks punctuated by regions of conserved sequence. These data suggest that 16S rDNA, while effective for both species-level and family-level phylogenetic reconstruction, may underperform for genus-level phylogenetic analyses in the Enterobacteriaceae.  相似文献   

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Is progesterone a pre-hormone in the CNS?   总被引:3,自引:0,他引:3  
In this paper, experimental evidences have been presented indicating that progesterone per se appears to be a powerful modulatory steroid of presynaptic striatal dopaminergic terminals of the central nervous system of the rat. This effect of the progesterone signal is concentration as well as infusion mode dependent. Low pulsatile doses of the steroid positively modulate the mechanism by which dopamine terminals respond to amphetamine stimulation and increase tissue dopamine concentration. Whereas, continuous and/or high doses of this steroid negatively modulate the response of the dopamine terminals to amphetamine stimulation and decreases tissue dopamine concentration. This effects occurs through a membrane mediated mechanism either upon the dopamine neuron directly and/or upon an interneuron. Pregnanolone a 5- beta-3 beta-metabolite of progesterone known to activate the hypothalamic LHRH neural apparatus at the level of the hypothalamus of ovariectomized estrogen primed rats in both in vitro as well as in vivo preparations was completely ineffective at the level of the corpus striatum of similar animal preparations. Therefore, it is reasonable to assume that site specific mechanisms exist within the central nervous system which may control differentially the final action of progesterone. In the hypothalamus, pregnanolone appears to be the final signal for its action on the LHRH neural apparatus, whereas in the corpus striatum, the steroid per se, and dependent on the modality and/or the strength of the signal can either directly or indirectly up-regulate (stimulatory component) or down-regulate (inhibitory component) the activity of striatal dopaminergic terminals.  相似文献   

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《Free radical research》2013,47(1-3):59-63
The age-specific incidence rates of adult cancer indicate that the carcinogenic process is a power function of elapsed time. If the malignant clone arises by a series of mutations, and each mutation is regarded as an independent event with a small instantaneous probability of occurrence, then the slope of the age-specific incidence gives an indication of the number of genes involved. In most cases, the epidemiological data exhibit an age-specific incidence the slope of which is between a fourth and a seventh power of age. Assuming that the mutations involved are deletions and must occur in otherwise viable and proliferative cells, the mutation rate required to generate enough mutant cells to fit the cancer incidence data must be remarkably high in the pre-malignant cell population. The initiation process may thus be an event that results in a raised mutation rate in the affected cell and its progeny. It is proposed that the process of induction involves one or more mutations that induce a metabolic lesion that has the effect of increasing the subsequent mutation rate in the affected clone. A possible mechanism involving free radical generation is suggested and some of the biological implications of the proposal examined.  相似文献   

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We tested the effectiveness of an intensive, on average 17-session, adaptive and computerized working-memory training program for improving performance on untrained, paper and pencil working memory tasks, standardized school achievement tasks, and teacher ratings of classroom behavior. Third-grade children received either a computerized working memory training for about 30 minutes per session (n = 156) or participated in regular classroom activities (n = 126). Results indicated strong gains in the training task. Further, pretest and posttest transfer measures of working memory and school achievement, as well as teacher ratings, showed substantial correlations with training task performance, suggesting that the training task captured abilities that were relevant for the transfer tasks. However, effect sizes of training-specific transfer gains were very small and not consistent across tasks. These results raise questions about the benefits of intensive working-memory training programs within a regular school context.  相似文献   

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Input–output tables (IOTs) provide a relevant picture of economic structure as they represent the composition and interindustry relationships of an economy. The technical coefficients matrix (A matrix) is considered to capture the technological status of an economy; so, it is of special relevance for the evaluation of long-term, structural transformations, such as sustainability transitions in integrated assessment models (IAMs). The A matrix has typically been considered either static or exogenous. Endogenous structural change has rarely been applied to models. The objective of this paper is to analyze energy intensity, a widely used variable in IAMs, and its role as a driver of structural change. We therefore identify the most relevant technical coefficients in the IOTs time series and estimate an econometric model based on the energy intensity of five different final end-use energy sources. The results of this analysis show that energy intensity has a significant influence on the evolution of the A matrix and should therefore be taken into consideration when analyzing endogenous structural change in models.  相似文献   

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13.

Background

Cognitive impairment occurs in about 50% of multiple sclerosis (MS) patients, and the use of self-reported outcomes for evaluating treatment and managing care among subjects with cognitive dysfunction has been questioned. The aim of this study was to provide new evidence about the suitability of self-reported outcomes for use in this specific population by exploring the internal structure, reliability and external validity of a specific quality of life (QoL) instrument, the Multiple Sclerosis International Quality of Life questionnaire (MusiQoL).

Methods

Design: cross-sectional study. Inclusion criteria: MS patients of any disease subtype. Data collection: sociodemographic (age, gender, marital status, education level, and occupational activity) and clinical data (MS subtype, Expanded Disability Status Scale, disease duration); QoL (MusiQoL and SF36); and neuropsychological performance (Stroop color-word test). Statistical analysis: confirmatory factor analysis, item-dimension correlations, Cronbach''s alpha coefficients, Rasch statistics, relationships between MusiQoL dimensions and other parameters.

Principal Findings

One hundred and twenty-four consecutive patients were enrolled. QoL scores did not differ between the 69 cognitively non-impaired patients and the 55 cognitively impaired patients, except for the symptoms dimension. The confirmatory factor analysis performed among the impaired subjects showed that the structure of the questionnaire matched with the initial structure of the MusiQoL. The unidimensionality of the MusiQoL dimensions was preserved, and the internal validity indices were satisfactory and close to those of the reference population.

Conclusions/Significance

Our study suggests that executive dysfunction did not compromise the reliability and the validity of the self-reported QoL questionnaires.  相似文献   

14.
The whole-part relationship is generally considered transitive, but there are some apparent exceptions. Componential sortals create some apparent problems. Homo sapiens, the Pope, and his heart are all individuals. A human being, such as the Pope, is an organism-level component of Homo sapiens. The Pope’s heart is an organ-level component of both Homo sapiens and the Pope. Although the Pope is a part, and not an instance, of the Roman Catholic Church, it seems odd to say that his heart is a part of that church. This is largely because the Pope’s heart does not have a place in the ecclesiastical government. However, it does contribute to the functioning of the organization. One popular alternative to the view that Homo sapiens is an individual is the notion that it is a natural kind. This has been done by redefining ‘natural kind’ in such a manner that not just the Roman Catholic Church, but the Pope and every other human being is a natural kind as well.  相似文献   

15.
Kalaska JF  Green A 《Neuron》2007,54(4):500-502
In redundant neural networks, many different combinations of connection weights will produce the same output, thereby providing many possible solutions for a given computation. In this issue of Neuron, Rokni et al. propose that the arm movement representations in the cerebral cortex act like redundant networks that drift randomly between different synaptic configurations with equivalent input-output behavior because of random noise in the adaptive learning mechanism.  相似文献   

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E. H. Watts 《CMAJ》1945,53(1):20-24
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18.
《PloS one》2013,8(8)
There has been a significant body of literature on species flock definition but not so much about practical means to appraise them. We here apply the five criteria of Eastman and McCune for detecting species flocks in four taxonomic components of the benthic fauna of the Antarctic shelf: teleost fishes, crinoids (feather stars), echinoids (sea urchins) and crustacean arthropods. Practical limitations led us to prioritize the three historical criteria (endemicity, monophyly, species richness) over the two ecological ones (ecological diversity and habitat dominance). We propose a new protocol which includes an iterative fine-tuning of the monophyly and endemicity criteria in order to discover unsuspected flocks. As a result nine « full » species flocks (fulfilling the five criteria) are briefly described. Eight other flocks fit the three historical criteria but need to be further investigated from the ecological point of view (here called « core flocks »). The approach also shows that some candidate taxonomic components are no species flocks at all. The present study contradicts the paradigm that marine species flocks are rare. The hypothesis according to which the Antarctic shelf acts as a species flocks generator is supported, and the approach indicates paths for further ecological studies and may serve as a starting point to investigate the processes leading to flock-like patterning of biodiversity.  相似文献   

19.
Doklady Biological Sciences - We have studied the dynamics of the singing of garden bunting (Emberiza hortulana) and the dispersal of a flock of starlings (Sturnus vulgaris) for the night rest. The...  相似文献   

20.
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