17 research outputs found

    Derivations of two-step nilpotent Leibniz algebras

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    In this paper we study the Lie algebras of derivations of two-step nilpotent Leibniz algebras. We obtain a class of Lie algebras with trivial center and abelian ideal of inner derivations. Among these, the relations between the complex and the real case of the indecomposable Heisenberg Leibniz algebras are thoroughly described. Finally we show that every almost inner derivation of a complex nilpotent Leibniz algebra with one-dimensional commutator ideal, with three exceptions, is an inner derivation.Comment: arXiv admin note: text overlap with arXiv:2106.1290

    Modelo de gestión de riesgos para proyectos de suministro de estructuras metálicas

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    Publicación a texto completo no autorizada por el autorLa presente investigación tiene como objetivo principal gestionar los impactos sobre los costos, tiempo y calidad en los Proyectos de Suministro de Estructuras Metálicas y para ello, por medio de una selección comparativa de metodologías de gestión de proyectos, se ha considerado la base teórica de Gestión de Riesgos de Proyectos de la Guía de Gestión de Proyecto del PMI por ser la herramienta con mayor aceptación y uso profesional a nivel mundial. La metodología de Gestión de Riesgos desarrollada guarda una estructura muy similar a la estructura propuesta por el PMI en la guía del PMBOK 5ta Edición, que va desde la identificación de los riesgos hasta la planificación y control de los mismos. Existen algunas diferencias en los documentos de entrada, salidas y herramientas y técnicas empleadas. Estos han sido adaptados según las particularidades del Caso de Estudio para que como resultado final y bajo el enfoque de que el riesgo se asume como una desviación del nivel deseado (Dziadosz A. & Rejment M., 2015), se plantean planes de respuesta a los riesgos y se establece la línea base de comparación de los niveles de aceptación de los riesgos, lo que permitirá contrastar la validez de los supuestos considerados en la formulación de estos planes de respuesta, detectar variaciones en los riesgos para registrarlos, dando lugar a una nueva iteración del proceso de gestión de riesgos de proyecto. El presente modelo pretende ser un ejemplo de implementación de una metodología de gestión de riesgos, que demuestre su importancia y su relación con el cumplimiento de los objetivos del proyecto, cuyo uso sea un referente sujeto a mejoras o adaptaciones según las características del proyecto de Suministro de Estructuras Metálicas asociado.Tesi

    Non-nilpotent Leibniz algebras with one-dimensional derived subalgebra

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    In this paper we study non-nilpotent non-Lie Leibniz F\mathbb{F}-algebras with one-dimensional derived subalgebra, where F\mathbb{F} is a field with char(F)2\operatorname{char}(\mathbb{F}) \neq 2. We prove that such an algebra is isomorphic to the direct sum of the two-dimensional non-nilpotent non-Lie Leibniz algebra and an abelian algebra. We denote it by LnL_n, where n=dimFLnn=\dim_{\mathbb{F}} L_n. This generalizes the result found in [11], which is only valid when F=C\mathbb{F}=\mathbb{C} . Moreover, we find the Lie algebra of derivations, its Lie group of automorphisms and the Leibniz algebra of biderivations of LnL_n. Eventually, we solve the coquecigrue problem for LnL_n by integrating it into a Lie rack

    Isotopisms of nilpotent Leibniz algebras and Lie racks

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    In this paper we study the isotopism classes of two-step nilpotent Leibniz algebras. We show that every nilpotent Leibniz algebra with one-dimensional commutator ideal is isotopic to the Heisenberg algebra h2n+1\mathfrak{h}_{2n+1} or to the Heisenberg Leibniz algebra l2n+1J1\mathfrak{l}_{2n+1}^{J_1}, where J1J_1 is the n×nn \times n Jordan block of eigenvalue 11. We also prove that two such algebras are isotopic if and only if the Lie racks integrating them are isotopic. This gives the classification, up to isotopism, of Lie racks whose tangent space at the unit element is a nilpotent Leibniz algebra with commutator ideal of dimension one. Eventually we introduce new isotopism invariants for Leibniz algebras and Lie racks.Comment: arXiv admin note: text overlap with arXiv:2106.1290

    Notulae to the Italian alien vascular flora: 11

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    In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Biderivations of complete Lie algebras

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    Biderivations of complete Lie algebra

    Pregnancy in an Asymptomatic Woman with Porencephalic and Arachnoid Cysts

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    A 25-year-old woman presented to the obstetric clinic in her first pregnancy. The patient was accompanied by her mother who reported an episode of intracerebral hemorrhage after birth and also remembered access to the emergency department after generalized tonic-clonic seizure as an infant. She was not able to describe the therapy for seizure preventions and even when and why it was suspended, but she affirmed that no residual neurological consequences were detected in the following years. Actually, the pregnant woman was in good health without neurological symptoms nor assumed any therapy. A neurologist reviewed the patient’s CT scan in which arachnoid cyst and porencephalic cyst were evident, and he assessed that no abnormalities were found in motor, sensory, and mental state examination. EEG did not show any epileptiform or seizure-like activity. No antiepileptic drug was prescribed due to the absence of symptoms since many years. The patient had no neurological symptoms during pregnancy or obstetric complications and delivered at term a healthy baby through a caesarean section. She breastfed, and after two years, the patient and the baby are healthy. The association of porencephalic and arachnoid cyst in pregnancy is an extremely rare neurological condition that needs a multidisciplinary counseling in pregnancy, but an uneventful course is possible
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