428 research outputs found

    A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses

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    We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermis–outermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants

    Greek Translation and Cultural Adaptation of the Short Version of the Maastricht Utrecht Adherence in Hypertension Questionnaire

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    Background: The recently published short version of the Maastricht Utrecht Adherence in Hypertension (MUAH) questionnaire (MUAH-16) suggests that MUAH-16 better represents a patient's adherence to antihypertensive medication than the original MUAH questionnaire. Objective: The aim of our study was the cultural adaptation and validation of the short MUAH-16 questionnaire in the Greek population. Methods: 10 patients were involved in the process of translation and cultural adaptation of MUAH-16, providing feedback on the final version, which was then administered to 100 patients. All patients received at least one antihypertensive drug during the last three months and were followed in the Hypertension-24h ABPM ESH Center of Excellence, Outpatient Clinic for the Treatment of Hypertension in the 3rd Internal Medicine Department of Papageorgiou General Hospital of Thessaloniki. Results: A factor analysis revealed a similar internal structure with four subscales that closely resembled the subscales in the original version of the questionnaire. Internal reliability indexes are equal or better than those of the original subscale structure. Conclusions: The Greek translation of the MUAH-16 is a good match for the original version with small, cultural differences. More research is needed in order to validate the proposed revised internal structure with a larger sample

    Thermal responses of single zone offices on existing near-extreme summer weather data

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    There have been a number of attempts in the past to define “near extreme” weather for facilitating overheating analysis in free running buildings. The most recently efforts include CIBSE latest release of Design Summer Year (DSY) weather using multiple complete weather years and a newly proposed composite DSY. This research aims to assess how various single zone offices respond to these new definitions of near extreme weathers. Parametric studies were carried out on single zone offices through which four sampling sets of models were employed to examine the thermal responses of dry bulb temperature, global solar radiation & wind speed collectively. London weather data from 1976 to 1995 were used and the overheating assessments were made based on CIBSE Guide A & BS EN 15251. The research discovers that solar radiation and wind both influence the predicted indoor warmth with solar radiation has obvious stronger impacts than wind. No perfect correlation was found from observation and Spearman’s rank order analysis on the ranks between the weather warmth and the predicted indoor warmth. The ranks made using multiple weather parameters show better correlation than some of the dry bulb temperature only metrics. The research also discovers that the Test Reference Year weather behaves warmer than expected. It is also found that a single complete year can not represent the near-extreme consistently and there is no evidence a composite DSY is better statistically. These findings support the notion of using multiple complete warm weather years for overheating assessments

    Cancer stem cell markers in breast cancer: pathological, clinical and prognostic significance

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    INTRODUCTION: The cancer stem cell (CSC) hypothesis states that tumours consist of a cellular hierarchy with CSCs at the apex driving tumour recurrence and metastasis. Hence, CSCs are potentially of profound clinical importance. We set out to establish the clinical relevance of breast CSC markers by profiling a large cohort of breast tumours in tissue microarrays (TMAs) using immunohistochemistry (IHC). METHODS: We included 4, 125 patients enrolled in the SEARCH population-based study with tumours represented in TMAs and classified into molecular subtype according to a validated IHC-based five-marker scheme. IHC was used to detect CD44/CD24, ALDH1A1, aldehyde dehydrogenase family 1 member A3 (ALDH1A3) and integrin alpha-6 (ITGA6). A 'Total CSC' score representing expression of all four CSC markers was also investigated. Association with breast cancer specific survival (BCSS) at 10 years was assessed using a Cox proportional-hazards model. This study was complied with REMARK criteria. RESULTS: In ER negative cases, multivariate analysis showed that ITGA6 was an independent prognostic factor with a time-dependent effect restricted to the first two years of follow-up (hazard ratio (HR) for 0 to 2 years follow-up, 2.4; 95% confidence interval (95% CI), 1.2 to 4.8; P = 0.009). The composite 'Total CSC' score carried independent prognostic significance in ER negative cases for the first four years of follow-up (HR for 0 to 4 years follow-up, 1.3; 95% CI, 1.1 to 1.6; P = 0.006). CONCLUSIONS: Breast CSC markers do not identify identical subpopulations in primary tumours. Both ITGA6 and a composite Total CSC score show independent prognostic significance in ER negative disease. The use of multiple markers to identify tumours enriched for CSCs has the greatest prognostic value. In the absence of more specific markers, we propose that the effective translation of the CSC hypothesis into patient benefit will necessitate the use of a panel of markers to robustly identify tumours enriched for CSCs

    Unsupervised level set parameterization using multi-scale filtering

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    This paper presents a novel framework for unsupervised level set parameterization using multi-scale filtering. A standard multi-scale, directional filtering algorithm is used in order to capture the orientation coherence in edge regions. The latter is encoded in entropy-based image `heatmaps', which are able to weight forces guiding level set evolution. Experiments are conducted on two large benchmark databases as well as on real proteomics images. The experimental results demonstrate that the proposed framework is capable of accelerating contour convergence, whereas it obtains a segmentation quality comparable to the one obtained with empirically optimized parameterization

    Applying balanced scorecard methodology in public sector: The case of a vocational school in Greece

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    Balanced Scorecard is a very important tool for management and evaluation of the long-term organization strategy, which simultaneously observes the improvements at the efficient function, exploiting the most of the organization’s potentials and diffusing the progress to all the employees. The implementation of Balanced Scorecard took place at the 5th Laboratory Centre (LC) of East Attica during the school year 2016-17, after the goals had been set and the measurement indicators had been defined by the school’s administration stuff (School Head, Deputy School Head, Teachers responsible for LC Sectors, Teachers responsible for Direction Laboratories, Teachers Board). The results indicated that the vision, the objectives and the overall strategy of the organization had been clarified and communicated to all customers. The administrative control of the progress of the procedures was more effective and the daily actions were connected with the objectives of the organization. Also it is important that all employees aligned with the organization's long-term strategy, and, furthermore, redesigning the model was possible. In the long term the appropriate background for the ongoing development of the organization and its effectiveness improvement in a constantly changing environment was created

    Applying balanced scorecard methodology in public sector: The case of a vocational school in Greece

    Get PDF
    Balanced Scorecard is a very important tool for management and evaluation of the long-term organization strategy, which simultaneously observes the improvements at the efficient function, exploiting the most of the organization’s potentials and diffusing the progress to all the employees. The implementation of Balanced Scorecard took place at the 5th Laboratory Centre (LC) of East Attica during the school year 2016-17, after the goals had been set and the measurement indicators had been defined by the school’s administration stuff (School Head, Deputy School Head, Teachers responsible for LC Sectors, Teachers responsible for Direction Laboratories, Teachers Board). The results indicated that the vision, the objectives and the overall strategy of the organization had been clarified and communicated to all customers. The administrative control of the progress of the procedures was more effective and the daily actions were connected with the objectives of the organization. Also it is important that all employees aligned with the organization's long-term strategy, and, furthermore, redesigning the model was possible. In the long term the appropriate background for the ongoing development of the organization and its effectiveness improvement in a constantly changing environment was created

    Self-adjusted active contours using multi-directional texture cues

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    Parameterization is an open issue in active contour research, associated with the cumbersome and time-consuming process of empirical adjustment. This work introduces a novel framework for self-adjustment of region-based active contours, based on multi-directional texture cues. The latter are mined by applying filtering transforms characterized by multi-resolution, anisotropy, localization and directionality. This process yields to entropy-based image “heatmaps”, used to weight the regularization and data fidelity terms, which guide contour evolution. Experimental evaluation is performed on a large benchmark dataset as well as on textured images. Τhe segmentation results demonstrate that the proposed framework is capable of accelerating contour convergence, maintaining a segmentation quality which is comparable to the one obtained by empirically adjusted active contours
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