Dynamics of a Dirac Fermion in the presence of spin noncommutativity

Recently, it has been proposed a spacetime noncommutativity that involves spin degrees of freedom, here called "spin noncommutativity". One of the motivations for such a construction is that it preserves Lorentz invariance, which is deformed or simply broken in other approaches to spacetime noncommutativity. In this work, we gain further insight in the physical aspects of the spin noncommutativity. The noncommutative Dirac equation is derived from an action principle, and it is found to lead to the conservation of a modified current, which involves the background electromagnetic field. Finally, we study the Landau problem in the presence of spin noncommutativity. For this scenario of a constant magnetic field, we are able to derive a simple Hermitean non-commutative correction to the Hamiltonian operator, and show that the degeneracy of the excited states is lifted by the noncommutativity at the second order or perturbation theory.Comment: 18 pages, revtex

Estado nutricional y parasitosis intestinales en niños residentes en zonas urbana, periurbana y rural del partido de Brandsen (Buenos Aires, Argentina)

El presente estudio tuvo como objeto analizar el estado nutricional y las parasitosis intestinales en niños de 3 a 6 años de edad, residentes en zonas urbanas (U), periurbanas (PU) y rurales (R) del partido de Brandsen. La muestra quedó constituida por 600 niños (302 varones y 298 mujeres). Los valores P85#P95 definieron sobrepeso y >P95 obesidad. Se tomaron muestras de materia fecal seriada y escobillado anal que fueron analizadas mediante técnicas de concentración por sedimentación (Ritchie) y flotación (Willis). Los datos fueron asociados con las características socioambientales de cada zona. PU presentó prevalencias de baja talla para la edad y parasitosis significativamente mayores que U (p<0.01). Se registraron 7 especies parásitas en U, 8 en PU y 4 en R, siendo Enterobius vermicularis, Blastocystis hominis y Giardia lamblia las especies más abundantes. También el poliparasitismo fue mayor en PU. Aunque el sobrepeso y la obesidad fueron elevados en las tres zonas, las mayores prevalencias se registraron en PU y R respecto de U (p<0.01). La coexistencia de desnutrición y sobrepeso-obesidad, podría vincularse con los cambios experimentados en las costumbres alimentarias y los modos de vida de estas poblaciones en el contexto de la transición nutricional. La zona periurbana presenta las peores condiciones socio-ambientales para el crecimiento y la salud de los niños en edad preescolar

Use of open mobile mapping tool to assess human mobility traceability in rural offline populations with contrasting malaria dynamics

Infectious disease dynamics are affected by human mobility more powerfully than previously thought, and thus reliable traceability data are essential. In rural riverine settings, lack of infrastructure and dense tree coverage deter the implementation of cutting-edge technology to collect human mobility data. To overcome this challenge, this study proposed the use of a novel open mobile mapping tool, GeoODK. This study consists of a purposive sampling of 33 participants in six villages with contrasting patterns of malaria transmission that demonstrates a feasible approach to map human mobility. The self-reported traceability data allowed the construction of the first human mobility framework in rural riverine villages in the Peruvian Amazon. The mobility spectrum in these areas resulted in travel profiles ranging from 2 hours to 19 days; and distances between 10 to 167 km. Most Importantly, occupational-related mobility profiles with the highest displacements (in terms of time and distance) were observed in commercial, logging, and hunting activities. These data are consistent with malaria transmission studies in the area that show villages in watersheds with higher human movement are concurrently those with greater malaria risk. The approach we describe represents a potential tool to gather critical information that can facilitate malaria control activities

Bio-Based Fire Retardant for Coco Lumber using Aloe barbadensis miller (Aloe Vera), Mangifera indica (Mango), or Persea americana (Avocado) and Boron Additives

Accidental fires are prevalent in low-income communities and one of the solutions to decrease fire risk is to apply fire retardants on combustible materials. While extensive research was available in creating fire retardants with inorganic chemicals, further studies are needed for bio-based fire retardants. The development of bio-based fire retardants involves testing organic matter for the presence of fire-retardant compounds such as nitrogen, phosphorus, and polyphenols. This study sought to determine the effectiveness of the peels of Aloe barbadensis miller (aloe vera), Mangifera indica (mangoes), and Persea americana (avocados) in creating bio-based fire retardants for coco lumber. Maceration was used to get the fruit and plant extracts. Boric acid and borax were also added as additives to boost fire retarding properties. The burning behavior of the lumber was observed in a modified horizontal flammability test and a modified flame spread test and measured in terms of mass loss, smoke density, char yield, and charring rate. The results revealed that among the fruits, the mango-based fire-retardant inhibited mass loss the most (M = 0.006, SD = 0.003), while the avocado-based fire-retardant inhibited smoke the most (M = 0.036, SD = 0.016). No significant difference was found among the groups as determined by One-way ANOVA and MANOVA (p \u3e 0.05). An indirect relationship was found between smoke density and char yield, which may be examined to improve the smoke suppressing ability of commercial fire retardants. Future studies may also refine the plant extracts and use standard flammability tests

Estudio de seroprevalencia de enfermedad de Chagas-Mazza en residentes del Cinturón Hortícola Platense

La Enfermedad de Chagas-Mazza, es silenciosa, frecuentemente ocasiona lesiones sin notables manifestaciones clínicas. Numerosas personas desconocen su condición de afectados por Tripanosoma cruzi. Cuando ellas tienen acceso a diagnósticos clínicos y seroepidemiológicos, puede ocurrir que haga ya muchos años que han sido afectados y haya daños orgánicos. En este estudio se realizaron actividades en territorio, en el cinturón frutihortícola platense en el que habitan personas provenientes de áreas endémicas de Enfermedad de Chagas-Mazza, como parte de un proyecto integral. Con consentimiento informado se realizaron extracciones y diagnósticos. Las personas seropositivas fueron luego estudiadas, seguidas y medicadas según cada caso siguiendo las indicaciones establecidas en los protocolos vigentes consensuados. Ellos no conocían su condición de afectados. Es necesario incrementar las acciones en el territorio a efectos de realizar diagnósticos tempranos y acciones oportunas.Chagas-Mazza disease is silent, frequently causes lesions without manifestations. notable clinical Many people are unaware of their status as affected by Trypanosoma cruzi. When they have access to clinical and seroepidemiological diagnoses, it may happen that they have been affected for years and there is organic damage. In this study, activities were carried out in the territory, in the La Plata fruit and vegetable belt where people from endemic areas of Chagas-Mazza disease live, as part of a comprehensive project. With informed consent, extractions and diagnoses were performed. The seropositive people were then studied, followed up and medicated according to each following the indications established in the current agreed protocols. They did not know their status as affected. It is necessary to increase actions in the territory in order to carry out early and timely actions.Facultad de Ciencias Veterinaria

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

Estimation of Admission D-dimer Cut-off Value to Predict Venous Thrombotic Events in Hospitalized COVID-19 Patients: Analysis of the SEMI-COVID-19 Registry

Background: Venous thrombotic events (VTE) are frequent in COVID-19, and elevated plasma D-dimer (pDd) and dyspnea are common in both entities. Objective: To determine the admission pDd cut-off value associated with in-hospital VTE in patients with COVID-19. Methods: Multicenter, retrospective study analyzing the at-admission pDd cut-off value to predict VTE and anticoagulation intensity along hospitalization due to COVID-19. Results: Among 9386 patients, 2.2% had VTE: 1.6% pulmonary embolism (PE), 0.4% deep vein thrombosis (DVT), and 0.2% both. Those with VTE had a higher prevalence of tachypnea (42.9% vs. 31.1%; p = 0.0005), basal O2 saturation &lt;93% (45.4% vs. 33.1%; p = 0.0003), higher at admission pDd (median [IQR]: 1.4 [0.6–5.5] vs. 0.6 [0.4–1.2] µg/ml; p &lt; 0.0001) and platelet count (median [IQR]: 208 [158–289] vs. 189 [148–245] platelets × 109/L; p = 0.0013). A pDd cut-off of 1.1 µg/ml showed specificity 72%, sensitivity 49%, positive predictive value (PPV) 4%, and negative predictive value (NPV) 99% for in-hospital VTE. A cut-off value of 4.7 µg/ml showed specificity of 95%, sensitivity of 27%, PPV of 9%, and NPV of 98%. Overall mortality was proportional to pDd value, with the lowest incidence for each pDd category depending on anticoagulation intensity: 26.3% for those with pDd &gt;1.0 µg/ml treated with prophylactic dose (p &lt; 0.0001), 28.8% for pDd for patients with pDd &gt;2.0 µg/ml treated with intermediate dose (p = 0.0001), and 31.3% for those with pDd &gt;3.0 µg/ml and full anticoagulation (p = 0.0183). Conclusions: In hospitalized patients with COVID-19, a pDd value greater than 3.0 µg/ml can be considered to screen VTE and to consider full-dose anticoagulation. © 2021, Society of General Internal Medicine