632 research outputs found

    Local Leaders in Random Networks

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    We consider local leaders in random uncorrelated networks, i.e. nodes whose degree is higher or equal than the degree of all of their neighbors. An analytical expression is found for the probability of a node of degree kk to be a local leader. This quantity is shown to exhibit a transition from a situation where high degree nodes are local leaders to a situation where they are not when the tail of the degree distribution behaves like the power-law kγc\sim k^{-\gamma_c} with γc=3\gamma_c=3. Theoretical results are verified by computer simulations and the importance of finite-size effects is discussed.Comment: 4 pages, 2 figure

    Visie van de Boergergroep

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    De BoergerGroep is een netwerk van burgers die met hart en ziel mee willen denken en mee willen praten over het platteland en hoe dat er in de toekomst uit kan zien. Zij hebben daarvoor met elkaar een visie opgesteld, die we hier gepresenteerd wordt. De BoergerGroep wil meedenken over de relatie tussen stad en platteland en welke kant het met de landbouw op moet

    Using the stated preference method for the calculation of social discount rate

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    The aim of this paper is to build the stated preference method into the social discount rate methodology. The first part of the paper presents the results of a survey about stated time preferences through pair-choice decision situations for various topics and time horizons. It is assumed that stated time preferences differ from calculated time preferences and that the extent of stated rates depends on the time period, and on how much respondents are financially and emotionally involved in the transactions. A significant question remains: how can the gap between the calculation and the results of surveys be resolved, and how can the real time preferences of individuals be interpreted using a social time preference rate. The second part of the paper estimates the social time preference rate for Hungary using the results of the survey, while paying special attention to the pure time preference component. The results suggest that the current method of calculation of the pure time preference rate does not reflect the real attitudes of individuals towards future generations

    Defective complex I assembly due to C20orf7 mutations as a new cause of Leigh syndrome

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    Background: Leigh syndrome is an early onset, progressive, neurodegenerative disorder with developmental and motor skills regression. Characteristic magnetic resonance imaging abnormalities consist of focal bilateral lesions in the basal ganglia and/or the brainstem. The main cause is a deficiency in oxidative phosphorylation due to mutations in an mtDNA or nuclear oxidative phosphorylation gene. Methods and results: A consanguineous Moroccan family with Leigh syndrome comprise 11 children, three of which are affected. Marker analysis revealed a homozygous region of 11.5 Mb on chromosome 20, containing 111 genes. Eight possible mitochondrial candidate genes were sequenced. Patients were homozygous for an unclassified variant (p.P193L) in the cardiolipin synthase gene (CRLS1). As this variant was present in 20% of a Moroccan control population and enzyme activity was only reduced to 50%, this could not explain the rare clinical phenotype in our family. Patients were also homozygous for an amino acid substitution (p.L159F) in C20orf7, a new complex I assembly factor. Parents were heterozygous and unaffected sibs heterozygous or homozygous wild type. The mutation affects the predicted S-adenosylmethionine (SAM) dependent methyltransferase domain of C20orf7, possibly involved in methylation of NDUFB3 during the assembly process. Blue native gel electrophoresis showed an altered complex I assembly with only 30-40% of mature complex I present in patients and 70-90% in carriers. Conclusions: A new cause of Leigh syndrome can be a defect in early complex I assembly due to C20orf7 mutations

    Identifying factors associated with sedentary time after stroke. Secondary analysis of pooled data from nine primary studies.

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    <p><b>Background</b>: High levels of sedentary time increases the risk of cardiovascular disease, including recurrent stroke.</p> <p><b>Objective</b>: This study aimed to identify factors associated with high sedentary time in community-dwelling people with stroke.</p> <p><b>Methods</b>: For this data pooling study, authors of published and ongoing trials that collected sedentary time data, using the activPAL monitor, in community-dwelling people with stroke were invited to contribute their raw data. The data was reprocessed, algorithms were created to identify sleep-wake time and determine the percentage of waking hours spent sedentary. We explored demographic and stroke-related factors associated with total sedentary time and time in uninterrupted sedentary bouts using unique, both univariable and multivariable, regression analyses.</p> <p><b>Results</b>: The 274 included participants were from Australia, Canada, and the United Kingdom, and spent, on average, 69% (SD 12.4) of their waking hours sedentary. Of the demographic and stroke-related factors, slower walking speeds were significantly and independently associated with a higher percentage of waking hours spent sedentary (p = 0.001) and uninterrupted sedentary bouts of <i>>30</i> and <i>>60 min</i> (p = 0.001 and p = 0.004, respectively). Regression models explained 11–19% of the variance in total sedentary time and time in prolonged sedentary bouts.</p> <p><b>Conclusion</b>: We found that variability in sedentary time of people with stroke was largely unaccounted for by demographic and stroke-related variables. Behavioral and environmental factors are likely to play an important role in sedentary behavior after stroke. Further work is required to develop and test effective interventions to address sedentary behavior after stroke.</p

    Численный анализ распространения и усиления волн цунами на северо-западном шельфе Черного моря

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    Выполнен численный анализ распространения длинных волн в северо-западной части Черного моря. Рассмотрено 10 возможных зон сейсмической генерации цунами. Расчеты выполнены на сетке с шагом 500 м. Показано, что положение очага цунами существенно влияет на распределение высот волн вдоль побережья. Как правило, наиболее интенсивные волны формируются у ближайшего участка берега. Землетрясения в Южнобережной сейсмической зоне не могут привести к цунамиопасности в западной части моря. Только сильные землетрясения в северо-западной части способны вызывать заметные колебания уровня Черного моря. Период цунами в районе Одессы составляет около 1 ч и зависит от магнитуды землетрясения, в районе Севастополя он в 2 – 3 раза меньше. В большинстве пунктов побережья экстремальные подъемы и понижения уровня моря не превышают по абсолютной величине начального смещения поверхности моря в очаге цунами. Для отдельных участков побережья Румынии и западного побережья Крыма наблюдается некоторое усиление волн, излученных из зон генерации, расположенных в более глубоководной части исследуемого района. С ростом магнитуды землетрясения усиление волн у берега становится более значительным.Виконаний чисельний аналіз розповсюдження довгих хвиль у північно-західній частині Чорного моря. Розглянуто 10 можливих зон сейсмічної генерації цунамі. Розрахунки виконані на сітці з кроком 500 м. Показано, що положення осередку цунамі суттєво впливає на розподіл висот хвиль уздовж побережжя. Як правило, найінтенсивніші хвилі формуються близько найближчої ділянки берега. Землетруси в південнобережній сейсмічній зоні не можуть призвести до цунамонебезпеки в західній частині моря. Лише сильні землетруси в північнозахідній частині здатні викликати помітні коливання рівня Чорного моря. Період цунамі в районі Одеси складає близько 1 години і залежить від магнітуди землетрусу, в районі Севастополя він в 2 – 3 рази менший. У більшості пунктів побережжя екстремальні підйоми і пониження рівня моря не перевищують за абсолютною величиною початкового зсуву поверхні моря в осередку цунамі. Для окремих ділянок побережжя Румунії і західного побережжя Криму спостерігається деяке посилення хвиль, які випромінюють із зон генерації, розташованих в більш глибоководній частині досліджуваного району. Із зростанням магнітуди землетрусу посилення хвиль біля берега стає значнішим.Numerical analysis of long wave propagation in the Black Sea northwestern part is carried out. Ten possible zones of tsunami seismic generation are considered. The calculation are performed on the grid with a step 500 m. It is shown that location of tsunami source effects essentially the distribution of waves’ heights along the coast. As a rule, the most intensive waves are formed in the part closest to the coast. Earthquakes in the South coast seismic zone can not result in tsunami threat in the western part of the sea. Only strong earthquakes in the Black Sea northwestern part can generate noticeable sea level oscillations. Tsunami period near Odessa is about one hour and it depends on the earthquake magnitude. In the Sevastopol region it is 2 – 3 times lower. In the majority of coastal points extreme rises and falls of the sea level do not exceed the absolute value of the initial sea surface elevation in the tsunami source. Some intensification of the waves generated in deeper regions of the area under study is possible in certain parts of the Romanian coast and the Crimean western coast. The wave intensification near the coast grows with the increase of the earthquake magnitude
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