149 research outputs found

    Assessing Lake Response to Extreme Climate Change Using the Coupled MIKE SHE/MIKE 11 Model: Case Study of Lake Zazari in Greece

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    Papadimos D, Demertzi K, Papamichail D. Assessing Lake Response to Extreme Climate Change Using the Coupled MIKE SHE/MIKE 11 Model: Case Study of Lake Zazari in Greece. Water. 2022; 14(6):921. https://doi.org/10.3390/w14060921Lakes, either artificial or natural, are greatly important as a component in their catchments’ hydrology, but also as ecosystem service providers. However, due to climate change, they have begun to face numerous problems with their water quality and quantity. Furthermore, general circulation models (GCMs) show future climate change with a reduction in rainfall and increase in temperature. The aim of the current study is to present an application where GCMs and state-of-the-art hydrological modelling system MIKE SHE/MIKE 11 are combined for assessing the response of a Greek lake in terms of its water balance and water level under climate change. Four general circulation models (GCMs; GFDL-CM3, MIROC-ESM-CHEM, MIROC-ESM, IPSL-CM5A-LR) for the extreme climate change scenario of RCP8.5 were used in the basin of Lake Zazari in Greece as a case study. Results showed that, by keeping the irrigated demands (the main water user) unchanged in the future, the lake exhibited a lower water level for all GCMs, fluctuating from −0.70 to −1.8 m for the mean (min)water level and from −0.30 to −1.20 m for the mean (max) water level. Instead of the above and by preserving the amount of withdraw water n from the lake at a certain percentage of inflows, the irrigated area should be reduced from 54.1% to 64.05% depending on the circulation model

    A Simplistic Approach for Assessing Hydroclimatic Vulnerability of Lakes and Reservoirs with Regulated Superficial Outflow

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    Demertzi, K.; Papadimos, D.; Aschonitis, V.; Papamichail, D. A Simplistic Approach for Assessing Hydroclimatic Vulnerability of Lakes and Reservoirs with Regulated Superficial Outflow. Hydrology 2019, 6, 61This study proposes a simplistic model for assessing the hydroclimatic vulnerability of lakes/reservoirs (LRs) that preserve their steady-state conditions based on regulated superficial discharge (Qd) out of the LR drainage basin. The model is a modification of the Bracht-Flyr et al. method that was initially proposed for natural lakes in closed basins with no superficial discharge outside the basin (Qd = 0) and under water-limited environmental conditions {mean annual ratio of potential/reference evapotranspiration (ETo) versus rainfall (P) greater than 1}. In the proposed modified approach, an additional Qd function is included. The modified model is applied using as a case study the Oreastiada Lake, which is located inside the Kastoria basin in Greece. Six years of observed data of P, ETo, Qd, and lake topography were used to calibrate the modified model based on the current conditions. The calibrated model was also used to assess the future lake conditions based on the future climatic projections (mean conditions of 2061-2080) derived by 19 general circulation models (GCMs) for three cases of climate change (three cases of Representative Concentration Pathways: RCP2.6, RCP4.5 and RCP8.5). The modified method can be used as a diagnostic tool in water-limited environments for analyzing the superficial discharge changes of LRs under di erent climatic conditions and to support the design of new management strategies for mitigating the impact of climate change on (a) flooding conditions, (b) hydroelectric production, (c) irrigation/industrial/domestic use and (d) minimum ecological flows to downstream rivers. Hydrology 6(3), 61. https://doi.org/10.3390/hydrology603006

    ANALYSIS OF PRIESTLEY-TAYLOR METHOD FOR THE ASSESSMENT OF REFERENCE EVAPOTRANSPIRATION IN GREECE

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    Στόχος της εργασίας είναι η εύρεση του εποχιακού σφάλματος στην εκτίμηση της εξατμισοδιαπνοής καλλιέργειας αναφοράς ΕΤο με τη μέθοδο Priestley-Taylor (P-T) και ο επαναπροσδιορισμός του συντελεστή μεταγωγής apt χρησιμοποιώντας τη μέθοδο Penman-Monteith κατά ASCE. Η ανάλυση έγινε για όλο τον ελλαδικό χώρο με χρήση GIS και μέσα μηνιαία κλιματικά δεδομένα της περιόδου 1950-2000. Η ανάλυση σφάλματος για το θερινό εξάμηνο Απριλίου-Σεπτεμβρίου έδειξε ότι η μέθοδος P-T παρουσιάζει αποδεκτές τιμές στο 75.3%, ενώ για το χειμερινό εξάμηνο Οκτωβρίου-Μαρτίου στο 20.2% της ελληνικής επικράτειας. Ο επαναπροσδιορισμός της μέσης τιμής του apt για το χειμερινό και θερινό εξάμηνο έδειξε ότι η χωρική μεταβλητότητά του παρουσιάζει συσχέτιση της τάξεως του ~94% με το έλλειμμα πίεσης κορεσμού υδρατμών. Από την ανάλυση της εποχιακής μεταβολής του συντελεστή apt εκτιμήθηκε η μέση τιμή του σε 1.29 και 1.51 για τη θερινή και χειμερινή περίοδο, αντίστοιχα.The aim of the study is to estimate the seasonal error in the assessment of reference crop evapotranspiration ΕΤο using the Priestley-Taylor (P-T) method and to revise the advection coefficient apt using as a base the ASCE standardized Penman-Monteith method. Analysis was performed for the Greek territory using GIS and gridded data which cover the mean monthly values of climatic parameters for the period 1950-2000. The analysis of seasonal error showed that P-T presents acceptable values in the 73.5% and 20.2% coverage of the greek territory for the dry-warm season (April-September) and the cold-wet season (October-March), respectively. Recalculation of apt for both seasons showed that its spatial variation is described at ~94% level by the vapor pressure deficit. The mean values of apt for the dry-warm season and the cold wet season were found to be 1.29 και 1.51, respectively

    ‘The International Teacher Leadership project,’ a case of international action research.

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    Copyright CARNThe paper arises from the International Teacher Leadership project, a research and development project involving researchers and practitioners in 14 European countries. The paper provides a conceptual exploration of the idea of teacher leadership and its role in educational reform, central to which is the idea that teachers, regardless of their level of power and organisational position, can engage in the leadership of enquiry-based development activity aimed at influencing their colleagues and embedding improved practices in their schools. The paper provides an outline of the project’s methodology which builds on that used in the Carpe Vitam Leadership for Learning project (Frost, 2008a). It is a form of collaborative action research which is highly developmental and discursive. It seeks to identify principles, strategies and tools that can be applied in a range of cultural settings. The paper includes a thematic analysis of the cultural contexts and policy environments of the participating countries in order to identify the obstacles to teacher leadership and to inform the nature of the support strategies employed

    Visual fixation in the vegetative state: an observational case series PET study

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    BACKGROUND: Assessment of visual fixation is commonly used in the clinical examination of patients with disorders of consciousness. However, different international guidelines seem to disagree whether fixation is compatible with the diagnosis of the vegetative state (i.e., represents "automatic" subcortical processing) or is a sufficient sign of consciousness and higher order cortical processing. METHODS: We here studied cerebral metabolism in ten patients with chronic post-anoxic encephalopathy and 39 age-matched healthy controls. Five patients were in a vegetative state (without fixation) and five presented visual fixation but otherwise showed all criteria typical of the vegetative state. Patients were matched for age, etiology and time since insult and were followed by repeated Coma Recovery Scale-Revised (CRS-R) assessments for at least 1 year. Sustained visual fixation was considered as present when the eyes refixated a moving target for more than 2 seconds as defined by CRS-R criteria. RESULTS: Patients without fixation showed metabolic dysfunction in a widespread fronto-parietal cortical network (with only sparing of the brainstem and cerebellum) which was not different from the brain function seen in patients with visual fixation. Cortico-cortical functional connectivity with visual cortex showed no difference between both patient groups. Recovery rates did not differ between patients without or with fixation (none of the patients showed good outcome). CONCLUSIONS: Our findings suggest that sustained visual fixation in (non-traumatic) disorders of consciousness does not necessarily reflect consciousness and higher order cortical brain function

    Attitudes Towards End-of-Life Decisions and the Subjective Concepts of Consciousness: An Empirical Analysis

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    Background: People have fought for their civil rights, primarily the right to live in dignity. At present, the development of technology in medicine and healthcare led to an apparent paradox: many people are fighting for the right to die. This study was aimed at testing whether different moral principles are associated with different attitudes towards end-of-life decisions for patients with a severe brain damage. Methodology: We focused on the ethical decisions about withdrawing life-sustaining treatments in patients with severe brain damage. 202 undergraduate students at the University of Padova were given one description drawn from four profiles describing different pathological states: the permanent vegetative state, the minimally conscious state, the locked-in syndrome, and the terminal illness. Participants were asked to evaluate how dead or how alive the patient was, and how appropriate it was to satisfy the patient's desire. Principal Findings: We found that the moral principles in which people believe affect not only people's judgments concerning the appropriateness of the withdrawal of life support, but also the perception of the death status of patients with severe brain injury. In particular, we found that the supporters of the Free Choice (FC) principle perceived the death status of the patients with different pathologies differently: the more people believe in the FC, the more they perceived patients as dead in pathologies where conscious awareness is severely impaired. By contrast, participants who agree with the Sanctity of Life (SL) principle did not show differences across pathologies. Conclusions: These results may shed light on the complex aspects of moral consensus for supporting or rejecting end-of-life decisions

    Instructional leadership in centralised systems: evidence from Greek high-performing secondary schools

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    This paper examines the enactment of instructional leadership (IL) in high-performing secondary schools (HPSS), and the relationship between leadership and learning in raising student outcomes and encouraging teachers’ professional learning in the highly centralised context of Greece. It reports part of a comparative research study focused on whether, and to what extent, IL has been embraced by Greek school leaders. The study is exploratory, using a qualitative multiple case design to examine two HPSS in Athens. The research design involved a qualitative approach using several different methods, including semi-structured interviews with school principals, deputy heads, subject teachers and subject advisers, plus observation of leadership practice and meetings and scrutiny of relevant policy documents. The findings show that IL is conceptualised as an informal collaborative leadership practice, interwoven with the official multi-dimension role of Greek principals and their ‘semi-IL’ role. In the absence of official IL ‘actors’, teachers’ leadership has been expanding

    Are there islands of awareness?

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    Ordinary human experience is embedded in a web of causal relations that link the brain to the body and the wider environment. However, there might be conditions in which brain activity supports consciousness even when that activity is fully causally isolated from the body and its environment. Such cases would involve what we call ‘islands of awareness’: conscious states that are neither shaped by sensory input nor able to be expressed by motor output. This paper considers conditions in which such islands might occur, including ex cranio brains, hemispherotomy, and in cerebral organoids. We examine possible methods for 2 detecting islands of awareness, and consider their implications for ethics and for the nature of consciousness

    Dying well with reduced agency: a scoping review and thematic synthesis of the decision-making process in dementia, traumatic brain injury and frailty

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    Background In most Anglophone nations, policy and law increasingly foster an autonomy-based model, raising issues for large numbers of people who fail to fit the paradigm, and indicating problems in translating practical and theoretical understandings of ‘good death’ to policy. Three exemplar populations are frail older people, people with dementia and people with severe traumatic brain injury. We hypothesise that these groups face some over-lapping challenges in securing good end-of-life care linked to their limited agency. To better understand these challenges, we conducted a scoping review and thematic synthesis. Methods To capture a range of literature, we followed established scoping review methods. We then used thematic synthesis to describe the broad themes emerging from this literature. Results Initial searches generated 22,375 references, and screening yielded 49, highly heterogeneous, studies that met inclusion criteria, encompassing 12 countries and a variety of settings. The thematic synthesis identified three themes: the first concerned the processes of end-of-life decision-making, highlighting the ambiguity of the dominant shared decision-making process, wherein decisions are determined by families or doctors, sometimes explicitly marginalising the antecedent decisions of patients. Despite this marginalisation, however, the patient does play a role both as a social presence and as an active agent, by whose actions the decisions of those with authority are influenced. The second theme examined the tension between predominant notions of a good death as ‘natural’ and the drive to medicalise death through the lens of the experiences and actions of those faced with the actuality of death. The final theme considered the concept of antecedent end-of-life decision-making (in all its forms), its influence on policy and decision-making, and some caveats that arise from the studies. Conclusions Together these three themes indicate a number of directions for future research, which are likely to be applicable to other conditions that result in reduced agency. Above all, this review emphasises the need for new concepts and fresh approaches to end of life decision-making that address the needs of the growing population of frail older people, people with dementia and those with severe traumatic brain injury

    Cildb: a knowledgebase for centrosomes and cilia

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    Ciliopathies, pleiotropic diseases provoked by defects in the structure or function of cilia or flagella, reflect the multiple roles of cilia during development, in stem cells, in somatic organs and germ cells. High throughput studies have revealed several hundred proteins that are involved in the composition, function or biogenesis of cilia. The corresponding genes are potential candidates for orphan ciliopathies. To study ciliary genes, model organisms are used in which particular questions on motility, sensory or developmental functions can be approached by genetics. In the course of high throughput studies of cilia in Paramecium tetraurelia, we were confronted with the problem of comparing our results with those obtained in other model organisms. We therefore developed a novel knowledgebase, Cildb, that integrates ciliary data from heterogeneous sources. Cildb links orthology relationships among 18 species to high throughput ciliary studies, and to OMIM data on human hereditary diseases. The web interface of Cildb comprises three tools, BioMart for complex queries, BLAST for sequence homology searches and GBrowse for browsing the human genome in relation to OMIM information for human diseases. Cildb can be used for interspecies comparisons, building candidate ciliary proteomes in any species, or identifying candidate ciliopathy genes
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