52 research outputs found

    Operaciones de cobertura con derivados Financieros- Validación producto Maíz Colombiano

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    En el presente trabajo de investigación, análisis y fundamentación se aplica la cobertura de riesgos de contratos a futuro, basados en el modelo de Black and Scholes, con respecto a los contratos de maíz con vencimiento en diciembre del año en curso, cuya finalidad es poder balancear los precios del producto buscando a futuro, no reporta grandes pérdidas y disminuir los riesgos presentes en la excesiva volatilidad del precio. En el trabajo se parte esclareciendo la importancia y aplicabilidad del modelo, a medida que se realizan monitoreos periódicos en fechas preestablecidas a los precios de las opciones del contrato, cuyas fechas inician el día 24 de septiembre y finalizan el día 21 de octubre, en las cuales se hace un estudio del comportamiento del mercado mediante análisis técnicos y fundamentales de cada fecha, tomando como referencia indicadores de cobertura tales como delta, gamma, beta y teta y lo que estas variables representan en el mercado de derivados y específicamente en el desarrollo del modelo de Black and Schole. Los monitoreos se enfocan al precio de las opciones de las primas call y put en las mismas fechas (24 de sep., 29 de sep., 7 de oct., 11 de oct., 14 de oct., 19 de oct., 21 de oct. y 29 de oct.) Es este sentido al momento de la aplicación del modelo de Black-Scholes, para determinar la sensibilidad de las variables implícitas en el mismo, se toma como referencia el subyacente respectivo al cada símbolo, la maduración establecida por la apertura y el vencimiento del contrato, la tasa de interés libre de riesgo de los Bonos del Tesoro a 30 años y la volatilidad liquidada para cada monitoreo sobre los precios históricos de 1 año anterior a cada fecha dada

    Simplifying and optimising the management of uncomplicated acute malnutrition in children aged 6–59 months in the Democratic Republic of the Congo (OptiMA-DRC): a non-inferiority, randomised controlled trial

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    BACKGROUND: Global access to acute malnutrition treatment is low. Different programmes using different nutritional products manage cases of severe acute malnutrition and moderate acute malnutrition separately. We aimed to assess whether integrating severe acute malnutrition and moderate acute malnutrition treatment into one programme, using a single nutritional product and reducing the dose as the child improves, could achieve similar or higher individual efficacy, increase coverage, and minimise costs compared with the current programmes. METHODS: We conducted an open-label, non-inferiority, randomised controlled trial in the Democratic Republic of the Congo. Acutely malnourished children aged 6-59 months with a mid-upper-arm circumference (MUAC) of less than 125 mm or oedema were randomly assigned (1:1), using specially developed software and random blocks (size was kept confidential), to either the current standard strategy (one programme for severe acute malnutrition using ready-to-use therapeutic food [RUTF] at an increasing dose as weight increased, another for moderate acute malnutrition using a fixed dose of ready-to-use supplementary food [RUSF]) or the OptiMA strategy (a single programme for both severe acute malnutrition and moderate acute malnutrition using RUTF at a decreasing dose as MUAC and weight increased). The primary endpoint was a favourable outcome at 6 months, defined as being alive, not acutely malnourished as per the definition applied at inclusion, and with no further episodes of acute malnutrition throughout the 6-month observation period; the endpoint was analysed in the intention-to-treat (all children) and per-protocol populations (participants who had a minimum prescription of 4 weeks' RUTF, received at least 90% of the total amount of RUTF they were supposed to receive as per the protocol, or were prescribed RUSF rations for a minimum of 4 weeks [ie, minimum of 28 RUSF sachets], and had a maximum interval of 6 weeks between any two visits in the 6-month follow-up). The non-inferiority analysis (margin 10%) was to be followed by a superiority analysis (margin 0%) if non-inferiority was concluded. This trial is registered at ClinicalTrials.gov, NCT03751475, and is now closed. FINDINGS: Between July 22 and Dec 6, 2019, 912 children were randomly assigned; after 16 were excluded, 896 were analysed (446 in the standard group and 450 in the OptiMA group). In the intention-to-treat analysis, 282 (63%) of 446 children in the standard group and 325 (72%) of 450 children in the OptiMA group had a favourable outcome (difference -9.0%, 95% CI -15.9 to -2.0). In the per protocol analysis, 161 (61%) of 264 children in the standard group and 291 (74%) of 392 children in the OptiMA group had a favourable outcome (-13.2%, -21.6 to -4.9). INTERPRETATION: In this non-inferiority trial treating children with MUAC of less than 125 mm or oedema, decreasing RUTF dose according to MUAC and weight increase proved to be a superior strategy to the standard protocol in the Democratic Republic of the Congo. These results demonstrate the safety and benefits of an approach that could substantially increase access to treatment for millions of children with acute malnutrition in sub-Saharan Africa. FUNDING: Innocent Foundation and European Civil Protection and Humanitarian Aid Operations. TRANSLATION: For the French translation of the abstract see Supplementary Materials section

    A National Spinal Muscular Atrophy Registry for Real-World Evidence.

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    BACKGROUND: Spinal muscular atrophy (SMA) is a devastating rare disease that affects individuals regardless of ethnicity, gender, and age. The first-approved disease-modifying therapy for SMA, nusinursen, was approved by Health Canada, as well as by American and European regulatory agencies following positive clinical trial outcomes. The trials were conducted in a narrow pediatric population defined by age, severity, and genotype. Broad approval of therapy necessitates close follow-up of potential rare adverse events and effectiveness in the larger real-world population. METHODS: The Canadian Neuromuscular Disease Registry (CNDR) undertook an iterative multi-stakeholder process to expand the existing SMA dataset to capture items relevant to patient outcomes in a post-marketing environment. The CNDR SMA expanded registry is a longitudinal, prospective, observational study of patients with SMA in Canada designed to evaluate the safety and effectiveness of novel therapies and provide practical information unattainable in trials. RESULTS: The consensus expanded dataset includes items that address therapy effectiveness and safety and is collected in a multicenter, prospective, observational study, including SMA patients regardless of therapeutic status. The expanded dataset is aligned with global datasets to facilitate collaboration. Additionally, consensus dataset development aimed to standardize appropriate outcome measures across the network and broader Canadian community. Prospective outcome studies, data use, and analyses are independent of the funding partner. CONCLUSION: Prospective outcome data collected will provide results on safety and effectiveness in a post-therapy approval era. These data are essential to inform improvements in care and access to therapy for all SMA patients

    Distinct Salmonella Enteritidis lineages associated with enterocolitis in high-income settings and invasive disease in low-income settings.

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    An epidemiological paradox surrounds Salmonella enterica serovar Enteritidis. In high-income settings, it has been responsible for an epidemic of poultry-associated, self-limiting enterocolitis, whereas in sub-Saharan Africa it is a major cause of invasive nontyphoidal Salmonella disease, associated with high case fatality. By whole-genome sequence analysis of 675 isolates of S. Enteritidis from 45 countries, we show the existence of a global epidemic clade and two new clades of S. Enteritidis that are geographically restricted to distinct regions of Africa. The African isolates display genomic degradation, a novel prophage repertoire, and an expanded multidrug resistance plasmid. S. Enteritidis is a further example of a Salmonella serotype that displays niche plasticity, with distinct clades that enable it to become a prominent cause of gastroenteritis in association with the industrial production of eggs and of multidrug-resistant, bloodstream-invasive infection in Africa.This work was supported by the Wellcome Trust. We would like to thank the members of the Pathogen Informatics Team and the core sequencing teams at the Wellcome Trust Sanger Institute (Cambridge, UK). We are grateful to D. Harris for work in managing the sequence data

    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

    Botulinum Neurotoxin type A is effective to treat peripheral myoclonus post-amputation

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    Peripheral myoclonus is a rare post-amputation complication characterized by sudden, brief and sometimes repetitive muscle contractions. BoNT-A prevents the release of the neurotransmitter acetylcholine at the axon ending of the neuromuscular junction and blocks contraction. Here, we present the case of a 57-year-old man with below-knee amputation due to infected post-traumatic aneurysm of the popliteal artery developed myoclonus in his stump who benefited from a 2-year Botulinum Neurotoxin type A injection treatment

    Investigation of clad ballooning during NSRR RIA tests using ALCYONE fuel performance code

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    International audienceALCYONE simulations of integral RIA transients performed on UO2 fuel rods prior to or within the ALPS program in the Japanese NSRR facility with stagnant liquid water coolant conditions are presented in this paper. The 11 selected tests which cover a wide range of fuel enthalpy increases (200 J/g - 800 J/g) aimed at assessing/challenging ALCYONE capabilities on four quantities of interest: clad outer surface peak temperature (293 K - 1200 K), film boiling duration (0 s - 2 s), clad residual hoop strain (0% - 25%) and transient fission gas release (2% - 25%). Despite a global consistency between measurements and ALCYONE predictions, paths are investigated to explain and reduce discrepancies. In particular, the reevaluation of fuel enthalpies by JAEA has led to revisit ALCYONE clad-to-water coolant heat exchange models which were derived from previous values of fuel enthalpies and suggested a recalibration of some of their parameters. Then, modeling the delayed gas axial flow in the free volumes of the rod is shown essential to achieve better residual hoop strain predictions in case of clad ballooning if proper timing of fission gas release, rod internal pressure increase and clad temperature elevation can be simulated. Key experimental and/or modeling research areas are shown to be at stake for future work

    A MOVING RESIDUAL LIMB: BOTULINUM TOXIN TO THE RESCUE

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    peer reviewedaudience: professionalMovement disorders post-amputation are a rare complication and can manifest as the jumping stump phenomenon, a form of peripheral myoclonus. The pathophysiology remains unknown and there is currently no standardized treatment. We describe the case of a 57-year-old male with unremitting stump myoclonus, starting one month after transtibial amputation, in his residual limb without associated phantom or neurological pain. The consequence of the myoclonus was a reduction in prosthetic wearing time. Failure to respond to oral medication led us to attempt the use of botulinum neurotoxin Type A injections in the involved muscles of the residual limb. Injection trials, over a two-year period, resulted in an improvement of movement disorder, an increased prosthetic wearing time and a higher satisfaction level of the patient. Injection of botulinum toxin type A should be considered as an alternative treatment for stump myoclonus to improve prosthetic wearing time and comfort
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