3,896 research outputs found

    Dirac Neutrinos and Dark Matter Stability from Lepton Quarticity

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    We propose to relate dark matter stability to the possible Dirac nature of neutrinos. The idea is illustrated in a simple scheme where small Dirac neutrino masses arise from a type--I seesaw mechanism as a result of a Z4Z_4 discrete lepton number symmetry. The latter implies the existence of a viable WIMP dark matter candidate, whose stability arises from the same symmetry which ensures the Diracness of neutrinos.Comment: 12 pages, 6 figures, Report N IFIC/16-4

    Intraindividual Variation in Nuclear DNA Content in Durvillaea Antarctica (Chamisso) Hariot, Macrocystis pyrifera (Linnaeus) C. Agardh and Lessonia spicata (Suhr) Santelices (Phaeophyceae)

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    Macrocystis C. Agardh, Durvillaea Bory and Lessonia Bory are three brown seaweeds genera of commercial importance for Chilean fishermen. Macrocystis pyrifera (Linnaeus) C. Agardh (Laminariales, Laminariaceae) is one of the world's most ecologically and economically important seaweed collected in Chile for alginate extraction; and as food for abalone aquaculture, Lessonia spicata (Suhr) Santelices (Laminariales, Lessoniaceae) represents more than 70% of the total brown seaweeds annual landing in Chile; and Durvillaea antarctica (Chamisso) Hariot (Fucales, Durvillaeaceae) is consumed as food, being considered very healthy because of its iodine content. Despite the economic importance of these species their nuclear DNA content is unknown until this moment. The present research was initiated to determine the nuclear DNA content and the intraindividual ploidy level variation in these seaweeds. The DNA-localizing fluorochrome DAPI (4',6-diamidino-2-phenylindole) and red blood cell (chicken erythrocyte) standard were used to estimate the nuclear DNA contents by image analysis. Durvillaea antarctica presented lower 2C DNA (1.2 pg) content and narrower range of DNA contents (1C-2C) than the Laminariales, which showed higher 2C DNA contents (1.4 -1.5 pg) and a wider range of ploidy level, achieving up to 4C in L. spicata and up to 8C in M. pyrifera. This higher ploidy levels observed would be related with the more complex cortical organization in the Laminariales than D. antarctica. 1C nuclei were only found in mature antheridia (D. antarctica) and sporangia (M. pyrifera and L. spicata). The 2C values observed for the taxa assessed were in the range of other previously published Fucales and Laminariales

    Mathematical and Anthropological Analysis of Northern Luzon Funeral Textile

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    The study presents a mathematical analysis and provides an anthropological perspective of the funeral textile of the indigenous communities in northern Luzon, Philippines. In particular, a symmetry analysis is performed, based on principles of group theory and transformation geometry, on the various repeating patterns found in funeral garments and blankets. Results show that particular frieze groups and plane crystallographic groups are favored due to choice of motifs which are reflective of cultural beliefs and funeral traditions, as well as weaving style and methodology. The results of the analysis point to the depth of mathematics present in the work of the weaver, who is able to arrive at meaningful geometric designs without formal training in mathematics. This study contributes directly to the branch of mathematics pertaining to mathematical crystallography in art and cultural heritage which deals, among others, with the use of group theoretic methods and tools in mathematical crystallography to understand the mathematics in artworks arising from various cultures all over the world. It provides further data and analysis to the growing body of literature that uses symmetry to enhance interpretation of culture from the artistic style of its artifacts

    Cálculo del impacto de una cuota compensatoria en el bienestar de los consumidores: Un caso ilustrativo

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    The most common approach used to evaluate changes in welfare has been the Consumer and Producer Surplus Analysis. This article presents a methodological alternative in order to evaluate in a more exact way this kind of modifications; in this sense, it includes some recent theoretical developments relating consumers welfare. By means of using the concept of Equivalent Variation and econometric and time series techniques, this work measures the impact of the implementation of antidumping duties on the imports of Chinese pommel locks in the mexican consumers welfare.

    Structural and Dynamic Characterization of Li-Ionic Liquid Electrolyte Solutions for Application in Li-Ion Batteries: A Molecular Dynamics Approach

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    Pyrrolidinium-based (Pyr) ionic liquids (ILs) have been proposed as electrolyte components in lithium-ion batteries (LiBs), mainly due to their higher electrochemical stability and wider electrochemical window. Since they are not naturally electroactive, in order to allow their use in LiBs, it is necessary to mix the ionic liquids with lithium salts (Li). Li-PF6, Li-BF4, and Li-TFSI are among the lithium salts more frequently used in LiBs, and each anion, namely PF6 (hexafluorophosphate), BF4 (tetrafluoroborate), and TFSI (bis(trifluoromethanesulfonyl)azanide), has its own solvation characteristics and interaction profile with the pyrrolidinium ions. The size of Pyr cations, the anion size and symmetry, and cation-anion combinations influence the Li-ion solvation properties. In this work, we used molecular dynamics calculations to achieve a comprehensive view of the role of each cation-anion combination and of different fractions of lithium in the solutions to assess their relative advantage for Li-ion battery applications, by comparing the solvation and structural properties of the systems. This is the most-comprehensive work so far to consider pyrrolidinium-based ILs with different anions and different amounts of Li: from it, we can systematically determine the role of each constituent and its concentration on the structural and dynamic properties of the electrolyte solutions

    Candida Periprosthetic Joint Infection: Is It Curable?

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    Fong; Infecció articular periprotèsica; Cirurgia d'intercanvi en dues etapesHongo; Infección de la articulación periprotésica; Cirugía de recambio en dos etapasFungus; Periprosthetic joint infection; Two-stage exchange surgeryCandida periprosthetic joint infection (CPJI) is a rare and very difficult to treat infection, and high-quality evidence regarding the best management is scarce. Candida spp. adhere to medical devices and grow forming biofilms, which contribute to the persistence and relapse of this infection. Typically, CPJI presents as a chronic infection in a patient with multiple previous surgeries and long courses of antibiotic therapy. In a retrospective series of cases, the surgical approach with higher rates of success consists of a two-stage exchange surgery, but the best antifungal treatment and duration of antifungal treatment are still unclear, and the efficacy of using an antifungal agent-loaded cement spacer is still controversial. Until more evidence is available, focusing on prevention and identifying patients at risk of CPJI seems more than reasonable.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

    Dificultades en la clasificaciĂłn del sĂ­ndrome metabĂłlico: El ejemplo de los adolescentes en MĂ©xico

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    OBJETIVO. Determinar la diferencia entre las definiciones del National Cholesterol Education Program Adult Treatment Panel (ATPIII) y de la International Diabetes Federation (IDF) para síndrome metabólico (SM) en adolescentes mexicanos. MATERIAL Y MÉTODOS. Estudio transversal en 575 adolescentes de 14 a 16 años. Se utilizaron pruebas t de Student, ji cuadrada y correlación de Spearman. RESULTADOS. La prevalencia de SM fue mayor por ATPIII (18.6%) versus IDF (8.2%) (p<0.001), con 41.1% de concordancia. CONCLUSIONES. Existe una diferencia estadística de la prevalencia del SM en adolescentes mexicanos entre las dos definiciones

    Can ePROMs improve the understanding and management of lung cancer patients’ Quality of Life? A Scoping review (Preprint)

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    Background: Electronic patient-reported outcome measures (ePROMs) are essential for clinical practice and research. The growth of electronic health technologies has provided unprecedented opportunities to collect information systematically through ePROMs. They are widely used in scientific research, but we need more evidence if they will also be used, with their implementation, in daily clinical practice. For example, patients with lung cancer have an advanced stage of the disease when diagnosed. This entails tremendous suffering due to high mortality and losses in the different dimensions of the human being. In this case, monitoring symptoms and other outcomes expressly represent great utility in improving a patient's quality of life. Objective: ePROMs provided unprecedented opportunities to collect information systematically. The authors aim to prove that ePROMs are more helpful in managing patient symptoms, lung cancer, and overall survival than their alternatives, such as non-electronic PROMs. Methods: This scoping review considered articles published between 2017 and 2022 identified through searches in PubMed, Scopus, Cochrane, CINAHL, and PsycINFO. We found 5,097 articles; after eliminating duplicates, we reduced them to 3,315, and after reading the abstract, we were left with 56; finally, after applying the exclusion criteria, we reviewed 12. Arksey and O'Malley's five-step framework was used to refine the initial search results with the following research questions: 1) Do ePROMs help physician-patient communication? 2) To what extent do they improve decision-making? 3) Are institutions and their digitization policies barriers or enablers for this process? 4) What else is needed for routine implementation?. Results: Twelve articles were included in this review. The answers to our questions were: 1) ePROMs are an integrative and facilitative communication tool, highlighting their importance in the relationship between palliative care and medical oncology. 2) ePROMs help assess patient symptoms and functionality more accurately and facilitate clinical decision-making. In addition, it allows more precise predictions of overall patient survival and the adverse effects of their treatments. 3) The main institutional obstacles are the initial investment, which can be costly, and the data protection policy. However, as enablers, we have better funding through the development of telemedicine, support from institutional leaders to overcome resistance to change, and transparent policies to ensure the safe and secure use of ePROMs. 4) More than evidence for its routine application, its implementation must overcome physicians' inertia and safeguard the confidentiality of the data obtained. Conclusions: Routine collection of remote ePROMs is an effective and valuable strategy for providing real-time clinical feedback. In addition, it provides satisfaction to patients and professionals. Optimizing ePROMs in lung cancer patients leads to a more accurate view of health outcomes and ensures quality patient follow-up. It also allows us to stratify patients based on their morbidity, creating specific follow-ups for their needs. However, data privacy and security are concerns when using ePROMs to ensure compliance with local entities. At least four barriers were identified: cost, complex programming within health systems, security, and socio-health literacy.info:eu-repo/semantics/publishedVersio

    Underestimation of Human Cutaneous Leishmaniasis Caused by Leishmania infantum in an Endemic Area of the Mediterranean Basin (Balearic Islands)

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    Leishmaniasis is an infectious zoonotic disease caused by protozoan parasites of the genus Leishmania. In the Mediterranean basin, leishmaniasis is caused by Leishmania infantum and transmitted by bites of sandflies of the genus Phlebotomus, with the dog as the main reservoir host. The most common form is cutaneous leishmaniasis (CL), although visceral cases also occur. The aim of this study was to assess the underestimation of CL in an endemic Mediterranean region. Thus, a retrospective study was performed on all CL cases diagnosed and treated in the Dermatology Service of Manacor Hospital (Majorca, Balearic Islands), and the data obtained were compared with those of local government epidemiological bulletins for the same period. The different clinical presentations were compiled, and data related to sex, age, and lesion type and number were analyzed. The results reveal a clear sub-notification, which indicates that the real incidence of human CL in this area is unknown. Keywords: Leishmania; cutaneous leishmaniasis; Majorca; subnotification of case
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