Dynamics of doublon-holon pairs in Hubbard two-leg ladders

The dynamics of holon-doublon pairs is studied in Hubbard two-leg ladders using the time-dependent Density Matrix Renormalization Group method. We find that the geometry of the two-leg ladder, that is qualitatively different from a one-dimensional chain due to the presence of a spin-gap, strongly affects the propagation of a doublon-holon pair. Two distinct regimes are identified. For weak inter-leg coupling, the results are qualitatively similar to the case of the propagation previously reported in Hubbard chains, with only a renormalization of parameters. More interesting is the case of strong inter-leg coupling where substantial differences arise, particularly regarding the double occupancy and properties of the excitations such as the doublon speed. Our results suggest a connection between the presence of a spin gap and qualitative changes in the doublon speed, indicating a weak coupling between the doublon to magnetic excitations.Comment: 8 pages, 9 figures. Published versio

Relative bioavailability and comparative clinical efficacy of different ivermectin oral formulations in lambs

Several oral ivermectin (IVM) formulations for use in sheep are available in the pharmaceutical veterinary market in different countries. All of them are indicated at the same dose rate to treat the gastrointestinal nematodes. However, there is a lack of information on the relative systemic exposure (plasma bioavailability) and clinical efficacy among oral formulations routinely used in sheep. The main goal of the work reported here was to perform a pharmaco-parasitological assessment of three different IVM oral formulations in lambs infected with multiple resistant gastrointestinal nematodes. The comparative drug systemic exposure (IVM plasma concentrations) and nematodicidal efficacies (clinical efficacy) in lambs were determined for a reference (RF) and two different test (T1, T2) IVM oral formulations. One hundred and fifty six (n= 156) healthy Corriedale lambs, naturally infected with multiple resistant gastrointestinal nematodes were allocated into four experimental groups (n=39). Animals in each group received treatment (200 μg/kg) with either the RF, one of the test IVM formulations or were kept as untreated control. Blood samples were collected over 15 days post-treatment (n=8). The IVM plasma concentrations were measured by high performance liquid chromatography with fluorescence detection. The faecal nematode egg count reduction test (FECRT) and evaluation of the clinical efficacy were performed at day 14 post-treatment (n=6), where a predominance of IVM highly resistant nematodes was observed. Results and conclusions Neither the overall kinetic behaviour nor the IVM systemic exposure differed among all the tested oral formulations. Equivalent efficacy results were obtained for the different preparations, with an evident therapeutic failure to control Haemonchus spp. and Teladorsagia circumcincta, which correlates with a high degree of nematode resistance to IVM.Fil: Suarez, Gonzalo. Universidad de la Republica; Uruguay;Fil: Alvarez, Luis Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigación Veterinaria de Tandil; Argentina;Fil: Castells, Daniel. Área de Investigación del Secretariado Uruguayo de la Lana; Uruguay;Fil: Correa, Oscar. Universidad de la Republica; Uruguay;Fil: Figiolino, Pietro. Universidad de la Republica; Uruguay;Fil: Lanusse, Carlos Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigación Veterinaria de Tandil; Argentina

Security analysis of communication system based on the synchronization of different order chaotic systems

This work analyzes the security weakness of a recently proposed communication method based on chaotic modulation and masking using synchronization of two chaotic systems with different orders. It is shown that its application to secure communication is unsafe, because it can be broken in two different ways, by high-pass filtering and by reduced order system synchronization, without knowing neither the system parameter values nor the system key.Comment: 12 pages, 6 figures, LaTeX forma

The HERC1 ubiquitin ligase regulates presynaptic membrane dynamics of central synapses

HERC1 is a ubiquitin ligase protein, which, when mutated, induces several malformations and intellectual disability in humans. The animal model of HERC1 mutation is the mouse tambaleante characterized by: (1) overproduction of the protein; (2) cerebellar Purkinje cells death by autophagy; (3) dysregulation of autophagy in spinal cord motor neurons, and CA3 and neocortical pyramidal neurons; (4) impairment of associative learning, linked to altered spinogenesis and absence of LTP in the lateral amygdala; and, (5) motor impairment due to delayed action potential transmission, decrease synaptic transmission efficiency and altered myelination in the peripheral nervous system. To investigate the putative role of HERC1 in the presynaptic dynamics we have performed a series of experiments in cultured tambaleante hippocampal neurons by using transmission electron microscopy, FM1-43 destaining and immunocytochemistry. Our results show: (1) a decrease in the number of synaptic vesicles; (2) reduced active zones; (3) less clathrin immunoreactivity and less presynaptic endings over the hippocampal main dendritic trees; which contrast with (4) a greater number of endosomes and autophagosomes in the presynaptic endings of the tambaleante neurons relative to control ones. Altogether these results show an important role of HERC1 in the regulation of presynaptic membrane dynamics

Propagation of nuclear data uncertainties in transmutation calculations using ACAB code

The assessment of the accuracy of parameters related to the reactor core performance (e.g, keff) and fuel cycle parameters (e.g. evolution/transmutation calculations) due to the uncertainties in the basic nuclear data (ND) is a critical issue. In performing this assessment, different error propagation techniques (adjoint/forward sensitivity analysis procedures and/or Monte Carlo technique) can be used to address by computational simulation the systematic propagation of uncertainty on the evaluation of the final responses. To perform this uncertainty evaluation the ENDF covariance files (variance/correlation in energy and cross-reactions-isotopes correlations) are required. In this paper, we assess the impact of ND uncertainties on the isotopic prediction for a conceptual design of a modular European Facility for Industrial Transmutation (EFIT) for a discharge burnup of 150 GWd/tHM. The complete set of uncertainty data for cross sections (EAF2007/UN, SCALE6.0/COVA-44G), radioactive decay and fission yield data (JEFF-3.1.1) are processed and used in ACAB code

Proyecto Utour

En el presente trabajo de investigación, tuvo como objetivo principal validar la idea de negocio del desarrollo de la aplicación Utour. Esta idea de negocio es una plataforma de servicio de turismo personalizado. Este negocio está dirigido a turistas nacionales y extranjeros, que les guste hacer turismo por su cuenta y tener el control de su tiempo en cada destino en el que se encuentre. Además, el negocio tiene un segundo segmento de clientes. Los negocios locales de servicios dirigidos a todo tipo de turistas. Al notar que la aplicación es una potencial ventana de publicidad, el negocio brindará el servicio de publicidad dentro de la aplicación, generando valor a este segmento de clientes. Con la disminución de los casos del Covid 19 y las restricciones impuestas por el gobierno por efectos de la pandemia, se ha establecido un crecimiento económico y una reactivación en el sector turismo tanto en el nacional y el receptivo. Se han analizado fuentes primarias y secundarias para validar la necesidad actual de ambos segmentos de clientes que puede ser aprovechado para el desarrollo de esta aplicación. La propuesta de valor de Utour ha demostrado que puede satisfacer las necesidades de ambos segmentos de clientes. Por último, se realizó el plan financiero del proyecto para poder corroborar la viabilidad de la idea de negocio. Se pudo determinar la inversión inicial, los costos y gastos operativos, administrativos y de venta, el financiamiento, así como también una estimación de ventas proyectadas y otros indicadores financieros. Se concluyó que el proyecto es viable a largo plazo, debido a que, se obtuvo un VAN positivo y un TIR superior a la tasa de descuento.In the following research, the main objective was to validate the business idea of ​​the development of the Utour application. This business idea is a personalized tourism service platform. This business is aimed at national and foreign tourists, who like to do tourism on their own and have control of their time in each destination where they are. In addition, the business has a second customer segment. Local service businesses aimed at all types of tourists. Realizing that the application is a potential advertising window, the business will provide the advertising service within the application, generating value for this customer segment. With the decrease in the cases of Covid 19 and the restrictions imposed by the government because of the pandemic, economic growth and a reactivation have been established in the tourism sector. Primary and secondary sources have been analyzed to validate the current need of both customer segments that can be used for the development of this application. Utour's value proposition has proven that it can meet the needs of both customer segments. Finally, the financial plan of the project was carried out in order to corroborate the viability of the business idea. It was possible to determine the initial investment, operating, administrative and sales costs and expenses, financing, as well as an estimate of projected sales and other financial indicators. It was concluded that the project is viable in the long term, because a positive NPV and an IRR higher than the discount rate were obtained.Trabajo de investigació

Effects of Supplementation with Microminerals on Production Indicators and Blood, Feces, and Urine Traces of Grazing Alpaca (Lama lama)

To analyze the effect of additional microminerals in the diet supplement on weight and diameter of alpaca fiber, the application of three doses of selenium and zinc (0.0; 1.0; and 1.5 cc) on the diet, on CRD factorial arrangement (3 x 2) + (3 x 2), was assessed. The results showed statistically significant differencences for treatments: selenium doses, ages, zinc doses, and for zinc interaction by ages (Se1E2 with 74.33 kg at 90 days, for height at the withers, Zn1E2, averaging 91.33 cm). Fiber length for treatments Se1E1 and Se1E2 averaged 3 cm. For fiber diameter, treatments 1 (Se0E1) and Se1E1, group 1, and treatments Zn0E2 and Zn1E1, group 2, showed the best fiber quality (P < 0.05), averaging 28 microns. Live weight and fiber quality from mature animals based on supplementation with Se and Zn had beneficial effects, which improved phenotypical features of production, like live weight, though residues were found in 3-5 year old animals

Risk of unintentional injuries in children and adolescents with ADHD and the impact of ADHD medications: A systematic review and meta-analysis

A systematic review with meta-analyses was performed to: 1) quantify the association between ADHD and risk of unintentional physical injuries in children/adolescents (¿risk analysis¿); 2) assess the effect of ADHD medications on this risk (¿medication analysis¿). We searched 114 databases through June 2017. For the risk analysis, studies reporting sex-controlled odds ratios (ORs) or hazard ratios (HRs) estimating the association between ADHD and injuries were combined. Pooled ORs (28 studies, 4,055,620 individuals without and 350,938 with ADHD) and HRs (4 studies, 901,891 individuals without and 20,363 with ADHD) were 1.53 (95% CI = 1.40,1.67) and 1.39 (95% CI = 1.06,1.83), respectively. For the medication analysis, we meta-analysed studies that avoided the confounding-by-indication bias [four studies with a self-controlled methodology and another comparing risk over time and groups (a ¿difference in differences¿ methodology)]. The pooled effect size was 0.879 (95% CI = 0.838,0.922) (13,254 individuals with ADHD). ADHD is significantly associated with an increased risk of unintentional injuries and ADHD medications have a protective effect, at least in the short term, as indicated by self-controlled studies