5,039 research outputs found

    Quantifying sleep architecture dynamics and individual differences using big data and Bayesian networks

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    The pattern of sleep stages across a night (sleep architecture) is influenced by biological, behavioral, and clinical variables. However, traditional measures of sleep architecture such as stage proportions, fail to capture sleep dynamics. Here we quantify the impact of individual differences on the dynamics of sleep architecture and determine which factors or set of factors best predict the next sleep stage from current stage information. We investigated the influence of age, sex, body mass index, time of day, and sleep time on static (e.g. minutes in stage, sleep efficiency) and dynamic measures of sleep architecture (e.g. transition probabilities and stage duration distributions) using a large dataset of 3202 nights from a non-clinical population. Multi-level regressions show that sex effects duration of all Non-Rapid Eye Movement (NREM) stages, and age has a curvilinear relationship for Wake After Sleep Onset (WASO) and slow wave sleep (SWS) minutes. Bayesian network modeling reveals sleep architecture depends on time of day, total sleep time, age and sex, but not BMI. Older adults, and particularly males, have shorter bouts (more fragmentation) of Stage 2, SWS, and they transition less frequently to these stages. Additionally, we showed that the next sleep stage and its duration can be optimally predicted by the prior 2 stages and age. Our results demonstrate the potential benefit of big data and Bayesian network approaches in quantifying static and dynamic architecture of normal sleep

    TIDE:A novel approach to constructing timed-release encryption

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    In ESORICS 2021, Chvojka et al. introduced the idea of taking a time-lock puzzle and using its solution to generate the keys of a public key encryption (PKE) scheme [13]. They use this to define a timed- release encryption (TRE) scheme, in which the secret key is encrypted ‘to the future’ using a time-lock puzzle, whilst the public key is published. This allows multiple parties to encrypt a message to the public key of the PKE scheme. Then, once a solver has spent a prescribed length of time evaluating the time-lock puzzle, they obtain the secret key and hence can decrypt all of the messages. In this work we introduce TIDE (TIme Delayed Encryption), a novel approach to constructing timed-release encryption based upon the RSA cryptosystem, where instead of directly encrypting the secret key to the future, we utilise number-theoretic techniques to allow the solver to factor the RSA modulus, and hence derive the decryption key. We implement TIDE on a desktop PC and on Raspberry Pi devices validating that TIDE is both efficient and practically implementable. We provide evidence of practicality with an extensive implementation study detailing the source code and practical performance of TIDE

    Bayesian Estimation of the Timing and Severity of a Population Bottleneck from Ancient DNA

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    In this first application of the approximate Bayesian computation approach using the serial coalescent, we demonstrated the estimation of historical demographic parameters from ancient DNA. We estimated the timing and severity of a population bottleneck in an endemic subterranean rodent, Ctenomys sociabilis, over the last 10,000 y from two cave sites in northern Patagonia, Argentina. Understanding population bottlenecks is important in both conservation and evolutionary biology. Conservation implications include the maintenance of genetic variation, inbreeding, fixation of mildly deleterious alleles, and loss of adaptive potential. Evolutionary processes are impacted because of the influence of small populations in founder effects and speciation. We found a decrease from a female effective population size of 95,231 to less than 300 females at 2,890 y before present: a 99.7% decline. Our study demonstrates the persistence of a species depauperate in genetic diversity for at least 2,000 y and has implications for modes of speciation in the incredibly diverse rodent genus Ctenomys. Our approach shows promise for determining demographic parameters for other species with ancient and historic samples and demonstrates the power of such an approach using ancient DNA

    Salty sensors, fresh ideas: The use of molecular and imaging sensors in understanding plankton dynamics across marine and freshwater ecosystems

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    Understanding plankton dynamics in marine ecosystems has been advanced using in situ molecular and imaging instrumentation. A range of research objectives have been addressed through high‐resolution autonomous sampling, from food web characterization to harmful algal bloom dynamics. When used together, molecular and imaging sensors can cover the full‐size range, genetic identity, and life stages of plankton. Here, we briefly review a selection of in situ instrumentation developed for the collection of molecular and imaging information on plankton communities in marine ecosystems. In addition, we interviewed a selection of instrumentation developers to determine if the transfer of sensor technology from marine to freshwater ecosystems is feasible and to describe the process of creating in situ sensors. Finally, we discuss the status of in situ molecular and imaging sensors in freshwater ecosystems and how some of the reviewed sensors could be used to address basic and applied research questions

    Promoviendo la justicia social a través del aprendizaje-servicio en la formación de maestros de Educación Infantil

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    As early childhood teacher education programs have begun to place greater emphasis on standards and accountability, there has been less focus on working with the community, and especially working on important social justice issues (Kroll, 2013). In this paper we argue that integrating service-learning and teacher education is a strategy for increasing awareness of social justice issues for young children, age three to grade three. Through the use of questionnaires and interviews to collect our data, we found that implementing a cascading service-learning model in teacher education programs has a positive transformative effect on Pre-Service Teachers. Additionally, we examined the effects of social justice service-learning projects on young children. The results from the data indicated that implementing a social justice service-learning project with these participants had a great impact or transformation on them.Como en los programas de formación del profesorado para la primera infancia han empezado a poner mayor énfasis en los estándares y la rendición de cuentas, se está haciendo menos hincapié en el trabajo con la comunidad, y especialmente en trabajos centrados en temas relevantes de justicia social (Kroll, 2013). En este artículo se argumenta que la integración del aprendizaje-servicio y la formación del profesorado es una estrategia para aumentar la conciencia sobre temas de justicia social con los niños pequeños, desde los tres años hasta tercer grado. A través del uso de cuestionarios y entrevistas para la recolección de datos, se encontró que la implementación de un modelo de aprendizaje-servicio en cascada en los programas de formación del profesorado tiene un efecto transformador positivo en profesores en formación. Además, se examinaron los efectos de los proyectos de aprendizaje-servicio de justicia social con niños pequeños. Los resultados de los datos indican que la implementación de un proyecto de aprendizaje-servicio de justicia social con estos participantes tiene un gran impacto o transformación en ellos.Os programas de formação do professorado para a primeira infância começaram a pôr maior ênfase nos padrões e a prestação de contas, dando-se menos ênfase ao trabalho com a comunidade, e especialmente em trabalhos centrados em temas relevantes de justiça social (Kroll, 2013). Neste artigo se argumenta que a integração do aprendizagem-serviço e a formação do professorado é uma estratégia para aumentar a consciência sobre temas de justiça social com as crianças pequenas, desde os três anos até o terceiro grau. Através do uso de questionário e entrevistas para a coleta de dados, encontrou-se que a implementação de um modelo de aprendizagem-serviço em cascata nos programas de formação de professores tem um efeito transformador positivo em professores em formação. Ademais, examinaramse os efeitos dos projetos de aprendizagem-serviço de justiça social com crianças pequenas. Os resultados dos dados indicam que a implantação de um projeto de aprendizagem-serviço de justiça social com estes participantes causa neles um grande impacto ou transformação

    C/EBPβ-1 promotes transformation and chemoresistance in Ewing sarcoma cells.

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    CEBPB copy number gain in Ewing sarcoma was previously shown to be associated with worse clinical outcome compared to tumors with normal CEBPB copy number, although the mechanism was not characterized. We employed gene knockdown and rescue assays to explore the consequences of altered CEBPB gene expression in Ewing sarcoma cell lines. Knockdown of EWS-FLI1 expression led to a decrease in expression of all three C/EBPβ isoforms while re-expression of EWS-FLI1 rescued C/EBPβ expression. Overexpression of C/EBPβ-1, the largest of the three C/EBPβ isoforms, led to a significant increase in colony formation when cells were grown in soft agar compared to empty vector transduced cells. In addition, depletion of C/EBPβ decreased colony formation, and re-expression of either C/EBPβ-1 or C/EBPβ-2 rescued the phenotype. We identified the cancer stem cell marker ALDH1A1 as a target of C/EBPβ in Ewing sarcoma. Furthermore, increased expression of C/EBPβ led to resistance to chemotherapeutic agents. In summary, we have identified CEBPB as an oncogene in Ewing sarcoma. Overexpression of C/EBPβ-1 increases transformation, upregulates expression of the cancer stem cell marker ALDH1A1, and leads to chemoresistance

    Gas Chromatography–Olfactometry Analyses of Volatiles Produced by ‘Fallglo’ and ‘US Early Pride’ Tangerines

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    ‘Fallglo’ is a popular tangerine (Citrus reticulata Blanco) cultivar with high eating quality. However, ‘Fallglo’ may contain as many as 30–40 seeds per fruit. ‘US Early Pride’ is a seedless mutation of ‘Fallglo’ with similar quality attributes. The objective of the current study was to determine if ‘Fallglo’ and ‘US Early Pride’ fruit differed in the composition or quantity of aroma-active volatiles produced over time. Fruit were harvested bi-weekly from October to December. Juice was carefully extracted from 50 fruit, and volatiles were analyzed using gas chromatography (GC). Two subjects evaluated the GC effluents by olfactometry in triplicate runs for each sample. Volatile identification was done by GC-mass spectrometry and confirmed by sniffing of authentic standards. The same 32 aroma-active compounds were perceived in ‘Fallglo’ and ‘US Early Pride’, of which 25 were identified. Compounds were classified in odor descriptor groups: fatty (10 compounds), plastic or rubber (seven compounds), fruity or citrus (four compounds), floral (four compounds), mushroom (two compounds), green (two compounds) and other (one compound). ‘Fallglo’ and ‘US Early Pride’ had similar aroma intensities for the three first harvests (26 Oct., 3 Nov., 17 Nov.), but ‘Fallglo’ had higher levels of two fruity odorous peaks (E-2-pentenal and the coeluting compounds E-2-hexenal and ethyl 2 methyl butanoate) than did ‘US Early Pride’ at the December harvest. The last harvest showed significantly higher aroma intensity for six peaks in each cultivar, with only two peaks in common in both cultivars
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