22 research outputs found

    Daylight: What Makes a Difference

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    Light is necessary for vision; it enables us to sense and perceive our surroundings and in many direct and indirect ways, via eye and skin, affects our physiological and psychological health. The use of light in built environments has comfort, behavioural, economic and environmental consequences. Daylight has many particular benefits including excellent visual performance, permitting good eyesight, effective entrainment of the circadian system as well as a number of acute non-image forming effects and the important role of vitamin D production. Some human responses to daylight seem to be well defined whilst others require more research to be adequately understood. This paper presents an overview of current knowledge on how the characteristics of daylight play a role in fulfilling these and other functions often better than electric lighting as conventionally delivered

    Novel homozygous missense mutation in GAN associated with Charcot-Marie-Tooth disease type 2 in a large consanguineous family from Israel.

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    BACKGROUND: CMT-2 is a clinically and genetically heterogeneous group of peripheral axonal neuropathies characterized by slowly progressive weakness and atrophy of distal limb muscles resulting from length-dependent motor and sensory neurodegeneration. Classical giant axonal neuropathy (GAN) is an autosomal recessively inherited progressive neurodegenerative disorder of the peripheral and central nervous systems, typically diagnosed in early childhood and resulting in death by the end of the third decade. Distinctive phenotypic features are the presence of "kinky" hair and long eyelashes. The genetic basis of the disease has been well established, with over 40 associated mutations identified in the gene GAN, encoding the BTB-KELCH protein gigaxonin, involved in intermediate filament regulation. METHODS: An Illumina Human CytoSNP-12 array followed by whole exome sequence analysis was used to identify the disease associated gene mutation in a large consanguineous family diagnosed with Charcot-Marie-Tooth disease type 2 (CMT-2) from which all but one affected member had straight hair. RESULTS: Here we report the identification of a novel GAN missense mutation underlying the CMT-2 phenotype observed in this family. Although milder forms of GAN, with and without the presence of kinky hair have been reported previously, a phenotype distinct from that was investigated in this study. All family members lacked common features of GAN, including ataxia, nystagmus, intellectual disability, seizures, and central nervous system involvement. CONCLUSIONS: Our findings broaden the spectrum of phenotypes associated with GAN mutations and emphasize a need to proceed with caution when providing families with diagnostic or prognostic information based on either clinical or genetic findings alone

    Hysteresis, Avalanches, and Disorder Induced Critical Scaling: A Renormalization Group Approach

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    We study the zero temperature random field Ising model as a model for noise and avalanches in hysteretic systems. Tuning the amount of disorder in the system, we find an ordinary critical point with avalanches on all length scales. Using a mapping to the pure Ising model, we Borel sum the 6−ϵ6-\epsilon expansion to O(ϵ5)O(\epsilon^5) for the correlation length exponent. We sketch a new method for directly calculating avalanche exponents, which we perform to O(ϵ)O(\epsilon). Numerical exponents in 3, 4, and 5 dimensions are in good agreement with the analytical predictions.Comment: 134 pages in REVTEX, plus 21 figures. The first two figures can be obtained from the references quoted in their respective figure captions, the remaining 19 figures are supplied separately in uuencoded forma

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Modelling human health risks from pesticide use in innovative legume-cereal intercropping systems in Mediterranean conditions

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    Background: The adoption of innovative cropping systems with low pesticide inputs would reduce environmental degradation and dependency on the use of plant protection products. Evaluating the pesticide risk to human health is a growing concern in the assessment of the sustainability of cropping practices. The assessment of human health risks linked to pesticide use in either conventional or innovative cropping systems is poorly documented in the literature. Objectives: This study focused on the assessment of pesticide exposure and human health risks from pesticide use in arable cropping systems (two monoculture and one intercropping system) associated with the use of various tillage practices (conventional tillage, reduced tillage, and no tillage). Methods: Human exposure (operators and residents) and health risks from pesticide use were assessed and compared between three conventional and six innovative cropping systems. We used the previously published BROWSE (Bystanders, Residents, Operators, and WorkerS Exposure) model based on data collected from interviews with the farmers and expert knowledge to compare the human health risk from pesticide use in the Setif area. Environmental conditions and the physical characteristics of the farmers were collected on three different farms from 2019 to 2021. Results: The modelling results demonstrate that human exposure to pesticides was systematically high under conservation tillage (no or reduced tillage) and monoculture cropping (pea and barley) conditions. It was also confirmed that operators experienced the highest cumulated exposure to pesticides (56 mg kg−1 bw day−1), followed by resident children seven days after pesticide application (0.66 mg kg−1 bw day−1). BROWSE simulations showed that dermal absorption was the most dominant route and represented more than 98% of the total amount of pesticides applied in all cropping × tillage system combinations. Regarding the overall results of the simulated human health risk, barley-pea intercropping was the most interesting system to reduce the risks for both operators and residents for all tillage practices. In addition, intercropping combined with conventional tillage was the most sustainable cropping system in terms of both agronomic performance (crop yield, Land Equivalent Ratio) and human health risk. Furthermore, the availability of advanced crop protection equipment was associated with a significant decrease in exposure and human health risk for both operators and residents. Conclusions: The prediction of human health risks using BROWSE could help farmers to make the decision to adopt conventional barley-pea intercropping as a good alternative to barley monocultures and pea monocultures under conservation tillage. © 2022 The Author

    Instabilités et chaos dans les oscillateurs paramétriques optiques

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    Nous discutons quelques mécanismes d'instabilité récemment observés dans un oscillateur paramétrique optique (OPO) : d'une part des instabilités opto-thermiques où le système oscille autour des courbes de résonance d'un ou plusieurs modes, d'autre part des oscillations rapides résultant de l'interaction de plusieurs modes transverses. La première observation expérimentale de chaos déterministe dans un OPO est également présentée
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