587 research outputs found
Energy Access and Electricity Planning
As developing countries look for ways to achieve sustainable energy services, which is essential to lift people out of poverty, the big challenge centers around providing access for all while avoiding past pitfalls without creating new ones. The reality is that this can only occur if there is a fundamental transformation of energy systems along the entire set of resource to energy service chains - and that will necessitate greater energy efficiency and a bigger role for renewables in the global energy mix energy. Competitive and private sector dominated energy markets rely on clear and consistent government energy-environment policies to align their investment decisions with sustainable development objectives. This paper tries to shed light on how developing countries can carry out energy planning by reviewing the available methodologies and tools, including their potential to integrate rural energy access and encourage the uptake of renewable energy technologies. It also probes how investment needs and cost-effectiveness are reflected in different analytic and planning tools - with a case study on Ethiopia. And it examines the interaction of energy planning and scenario development and how these are applied to informed policy making. The findings suggest that energy planning is essential and feasible. However, support is required to improve data collection and access, develop open accessible modelling tools, and build sustainable national capacity to undertake plannin
The Learning Theories Profile: A metacognitive tool for reflecting on professional practice
The Learning Theories Profile (LTP) supports professionals to locate various learning theories within four epistemological quadrants of the Matrix of Perspectives. Professionals can use this tool to identify some of the theories they hold and to reflect on the alignment between their espoused theories and theories-in-use. Forty-four Resource Teachers used the LTP and demonstrated that they were guided by a range of theories, most commonly interactive theories. A strong relationship was observed between espoused and in-use theories. Participants’ responses indicated the positive value of the LTP for supporting professionals to analyse and optimise interaction occurring in complex contexts of practice
Desalination using renewable energy sources on the arid islands of South Aegean Sea
Water and energy supply are strongly interrelated and their efficient management is crucial for a sustainable future. Water and energy systems on several Greek islands face a number of pressing issues. Water supply is problematic as regards both to the water quality and quantity. There is significant lack of water on several islands and this is mainly dealt with tanker vessels which transport vast amounts of water from the mainland. At the same time island energy systems are congested and rely predominanty on fossil fuels, despite the abundant renewable energy potential. These issues may be addressed by combining desalination and renewable energy technologies. It is essential to analyse the feasibility of this possibility. This study focuses on developing a tool capable of designing and optimally sizing desalination and renewable energy units. Several parameters regarding an island's water demandand the desalination's energy requirements are taken into account as well as input data which concern technological performance, resource availability and economic data. The tool is applied on three islands in the South Aegean Sea, Patmos (large), Lipsoi (medium) ad Thirasia (small). Results of the modelling exercise show that the water selling price ranges from 1.45 euro/m^3 for the large island, while the corresponding value is about 2.6 euro/m^3 for the small island, figures significantly lower than the current water cost (7-9 euro/m^3)
Association between cognitive performance and cortical glucose metabolism in patients with mild Alzheimer's disease
Background: Neuronal and synaptic function in Alzheimer's disease (AD) is measured in vivo by glucose metabolism using positron emission tomography (PET). Objective: We hypothesized that neuronal activation as measured by PET is a more sensitive index of neuronal dysfunction than activity during rest. We investigated if the correlations between dementia severity as measured with the Mini Mental State Examination (MMSE) and glucose metabolism are an artifact of brain atrophy. Method: Glucose metabolism was measured using {[}F-18]fluorodeoxyglucose PET during rest and activation due to audiovisual stimulation in 13 mild to moderate AD patients (MMSE score >= 17). PET data were corrected for brain atrophy. Results: In the rest condition, glucose metabolism was correlated with the MMSE score primarily within the posterior cingulate and parietal lobes. For the activation condition, additional correlations were within the primary and association audiovisual areas. Most local maxima remained significant after correcting for brain atrophy. Conclusion: PET activity measured during audiovisual stimulation was more sensitive to functional alterations in glucose metabolism in AD patients compared to the resting PET. The association between glucose metabolism and MMSE score was not dependent on brain atrophy. Copyright (C) 2005 S. Karger AG, Basel
Rapid functionalisation and detection of viruses via a novel Ca2+-mediated virus-DNA interaction
Current virus detection methods often take significant time or can be limited in sensitivity and specificity. The increasing frequency and magnitude of viral outbreaks in recent decades has resulted in an urgent need for diagnostic methods that are facile, sensitive, rapid and inexpensive. Here, we describe and characterise a novel, calcium-mediated interaction of the surface of enveloped viruses with DNA, that can be used for the functionalisation of intact virus particles via chemical groups attached to the DNA. Using DNA modified with fluorophores, we have demonstrated the rapid and sensitive labelling and detection of influenza and other viruses using single-particle tracking and particle-size determination. With this method, we have detected clinical isolates of influenza in just one minute, significantly faster than existing rapid diagnostic tests. This powerful technique is easily extendable to a wide range of other enveloped pathogenic viruses and holds significant promise as a future diagnostic tool
Advancements in the Treatment of Cerebrovascular Complications of Cancer
Purpose of review: To present the new guidelines and therapeutic options regarding cerebrovascular complications of cancer, mainly ischemic stroke, cerebral venous thrombosis (CVT), and leptomeningeal carcinomatosis (LMC).
Recent findings: A temporal trend study (2019) revealed that clinicians are still reluctant to apply thrombolysis to cancer patients, although two new studies (2018) reported no increased mortality. Several clinical trials on direct oral anticoagulants (DOACs) showed their superiority or, at least, non-inferiority compared with low molecular weight heparins in the treatment of venous thromboembolism (VTE) (2018–2019). These trials helped in formulating the new guidelines that are being published and the decisions made for cancer-associated thrombosis (CAT) as a whole. A new DOAC antidote was also officially released (US 2018, Europe 2019). Summary: Thrombolysis is safe in a malignancy setting, thus cancer per se should not be considered a contraindication for thrombolysis. Clinical trials assessing the newest DOACs for cancer-associated arterial thrombosis are scarce; however, based on data from VTE studies, the newest DOACs seem to be safe for CAT in patients that are not in high risk of bleeding or suffering from certain malignancies. The treatment should not be ceased after 6 months, but rather continued as long as the cancer remains active. Decompressive craniectomy should maintain its place in patients with CVST in risk of herniation. Last, the future also holds much promise on the role of novel compounds to be used in LMC
Lighting the World: the first application of an open source, spatial electrification tool (OnSSET) on Sub-Saharan Africa
In September 2015, the United Nations General Assembly adopted Agenda 2030, which comprises a set of 17 Sustainable Development Goals (SDGs) defined by 169 targets. 'Ensuring access to affordable, reliable, sustainable and modern energy for all by 2030' is the seventh goal (SDG7). While access to energy refers to more than electricity, the latter is the central focus of this work. According to the World Bank's 2015 Global Tracking Framework, roughly 15% of the world's population (or 1.1 billion people) lack access to electricity, and many more rely on poor quality electricity services. The majority of those without access (87%) reside in rural areas. This paper presents results of a geographic information systems approach coupled with open access data. We present least-cost electrification strategies on a country-by-country basis for Sub-Saharan Africa. The electrification options include grid extension, mini-grid and stand-alone systems for rural, peri-urban, and urban contexts across the economy. At low levels of electricity demand there is a strong penetration of standalone technologies. However, higher electricity demand levels move the favourable electrification option from stand-alone systems to mini grid and to grid extensions
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Psychometric properties of discourse measures in aphasia: acceptability, reliability, and validity
BACKGROUND: Discourse in adults with aphasia is increasingly the focus of assessment and therapy research. A broad range of measures is available to describe discourse, but very limited information is available on their psychometric properties. As a result, the quality of these measures is unknown, and there is very little evidence to motivate the choice of one measure over another. AIMS: To explore the quality of a range of discourse measures, targeting sentence structure, coherence, story structure and cohesion. Quality was evaluated in terms of the psychometric properties of acceptability (data completeness and skewness), reliability (inter- and intra-rater), and validity (content, convergent, discriminant and known groups). METHODS & PROCEDURES: Participants with chronic mild-to-moderate aphasia were recruited from community groups. They produced a range of discourses which were grouped into Cinderella and everyday discourses. Discourses were then transcribed orthographically and analyzed using macro- and microlinguistic measures (Story Grammar, Topic Coherence, Local Coherence, Reference Chains and Predicate Argument Structure-PAS). Data were evaluated against standard predetermined criteria to ascertain the psychometric quality of the measures. OUTCOMES & RESULTS: A total of 17 participants took part in the study. All measures had high levels of acceptability, inter- and intra-rater reliability, and had good content validity, as they could be related to a level of the theoretical model of discourse production. For convergent validity, as expected, 8/10 measures correlated with the Western Aphasia Battery-Revised (WAB-R) spontaneous speech scores, and 7/10 measures correlated with the Kissing and Dancing Test (KDT) scores (r ≥ 0.3), giving an overall positive rating for construct validity. For discriminant validity, as predicted, all measures had low correlations with Raven's Coloured Progressive Matrices (RCPM) and WAB-R Auditory Verbal Comprehension scores (r < 0.3), giving an overall positive rating for construct validity. Finally, for known groups validity, all measures indicated a difference between speakers with mild and moderate aphasia except for the Local Coherence measures. Overall, Story Grammar, Topic Coherence, Reference Chains and PAS emerged as the strongest measures in the current study because they achieved the predetermined thresholds for quality in terms of each of the psychometric parameters profiled. CONCLUSIONS & IMPLICATIONS: The current study is the first to psychometrically profile measures of discourse in aphasia. It contributes to the field by identifying Story Grammar, Topic Coherence, Reference Chains and PAS as the most psychometrically robust discourse measures yet profiled with speakers with aphasia. Until further data are available indicating the strength of other discourse measures, caution should be applied when using them
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