Damages caused by cotton rat, Sigmodon hispidus zanjonensis, on sugar cane in San Pedrosula, Honduras

Technical assistance was given to Compañía Azucarera Hondureña, S.A. (Agro-Industrial Co.), Honduras, Central America, to determine if a campaign against noxious rodents to agriculture crops was needed. Several trappings were carried out at different places using snap traps to determine the population structure of rodents associated with the crop, and live traps to determine the index or density of the Sigmodon hispidus rat population, which was identified as being responsible for the damage to sugarcane. Results were 43.24% adult males, 14.86% young males, 31.41% adult females, and 10.47% young females. Of the adult females captured, 54.83% were pregnant with an average of 3 to 4 embryos per rat. A control demonstration combat was carried out at one of the experimental stations with a bait prepared with 2% zinc phosphide in a place where it had been previously determined there was a population of 39 rats per hectare. After such control, the population was reduced to 18 rats per hectare, which represents an efficiency of 53.85%. An evaluation of damages was also measured at different places to determine the degree of loss caused by the rats, which proved to be 22.79% damage. The size of the sample was estimated in 3 samples per hectare, with a level of confidence of 95%

Dipolar glass polymers containing polarizable groups as dielectric materials for energy storage applications. A minireview

Materials that have high dielectric constants, high energy densities and minimum dielectric losses are highly desirable for use in capacitor devices. In this sense, polymers and polymer blends have several advantages over inorganic and composite materials, such as their flexibilities, high breakdown strengths, and low dielectric losses. Moreover, the dielectric performance of a polymer depends strongly on its electronic, atomic, dipolar, ionic, and interfacial polarizations. For these reasons, chemical modification and the introduction of specific functional groups (e.g., F, CN and R−S(=O)2−R´) would improve the dielectric properties, e.g., by varying the dipolar polarization. These functional groups have been demonstrated to have large dipole moments. In this way, a high orientational polarization in the polymer can be achieved. However, the decrease in the polarization due to dielectric dissipation and the frequency dependency of the polarization are challenging tasks to date. Polymers with high glass transition temperatures (Tg) that contain permanent dipoles can help to reduce dielectric losses due to conduction phenomena related to ionic mechanisms. Additionally, sub-Tg transitions (e.g., γ and β relaxations) attributed to the free rotational motions of the dipolar entities would increase the polarization of the material, resulting in polymers with high dielectric constants and, hopefully, dielectric losses that are as low as possible. Thus, polymer materials with high glass transition temperatures and considerable contributions from the dipolar polarization mechanisms of sub-Tg transitions are known as “dipolar glass polymers”. Considering this, the main aspects of this combined strategy and the future prospects of these types of material were discussed

Modulación no-ortogonal mediante los modelos Legendre-Fourier y Taylor-Fourier

Las bases de expansion ortogonales son ampliamente utilizadas tanto en los algoritmos de procesamiento digital de señales (DSP) como en el MOdulador-DEModulador (MODEM) de los sistemas de comunicaciones digitales. En el presente trabajo se explora desempeño de un par de esquemas de modulación no-ortogonal Legendre-Fourier (LF) y Taylor Fourier (TF) y se evalúa su razón de error binaria (BER) en un canal de ruido blanco aditivo gausiano (AWGN)

Ventricular remodelling in rabbits with sustained high‐fat diet

Aim Excess weight gain and obesity are one of the most serious health problems in the western societies. These conditions enhance risk of cardiac disease and have been linked with increased prevalence for cardiac arrhythmias and sudden death. Our goal was to study the ventricular remodelling occurring in rabbits fed with high‐fat diet ( HFD ) and its potential arrhythmogenic mechanisms. Methods We used 15 NZW rabbits that were randomly assigned to a control ( n  = 7) or HFD group ( n  = 8) for 18 weeks. In vivo studies included blood glucose, electrocardiographic, and echocardiographic measurements. Optical mapping was performed in Langendorff‐perfused isolated hearts. Results Body weight (3.69 ± 0.31 vs. 2.94 ± 0.18 kg, P  < 0.001) and blood glucose levels (230 ± 61 vs. 141 ± 14 mg dL −1 , P  < 0.05) were higher in the HFD group vs. controls. The rate‐corrected QT interval and its dispersion were increased in HFD rabbits vs. controls (169 ± 10 vs. 146 ± 13 ms and 37 ± 11 vs. 9 ± 2 ms, respectively; P  < 0.05). Echocardiographic analysis showed morphological and functional alterations in HFD rabbits indicative of left ventricle (LV) hypertrophy. Isolated heart studies revealed no changes in repolarization and propagation properties under conditions of normal extracellular K + , suggesting that extrinsic factors could underlie those electrocardiographic modifications. There were no differences in the dynamics of ventricular fibrillation (frequency, wave breaks) in the presence of isoproterenol. However, HFD rabbits showed a small reduction in action potential duration and an increased incidence of arrhythmias during hyperkalaemia. Conclusion High‐fat feeding during 18 weeks in rabbits induced a type II diabetes phenotype, LV hypertrophy, abnormalities in repolarization and susceptibility to arrhythmias during hyperkalaemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106944/1/apha12185.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/106944/2/apha12185-sup-0001-FigS1-S4TableS1-S3.pd

Effects of autogenous healing on the recovery of mechanical performance of High Performance Fibre Reinforced Cementitious Composites (HPFRCCs): Part 1

[EN] This paper presents the results are shown of a thorough characterization of the self-healing capacity of High Performance Fibre Reinforced Cementitious Composites (HPFRCCs). The capacity of the material will be investigated to completely or partially re-seal the cracks, as a function of its composition, maximum crack width and exposure conditions. The analysis will also consider different flow-induced alignments of fibres, which can result into either strain-hardening or softening behaviour, whether the material is stressed parallel or perpendicularly to the fibres, respectively. Beam specimens, initially pre-cracked in 4-point bending up to different values of crack opening, were submitted to different exposure conditions, including water immersion, exposure to humid or dry air, and wet-and-dry cycles. After scheduled exposure times, ranging from one month to two years, specimens were tested up to failure according to the same test set-up employed for pre-cracking. Outcomes of the self-healing phenomenon, if any, were analyzed in terms of recovery of stiffness, strength and ductility. In a durability-based design framework, self-healing indices quantifying the recovery of mechanical properties were also defined and their significance cross-checked.The support of Politecnico di Milano - Young Researchers 2011 grant to the project Self-healing capacity of cementitious composites is gratefully acknowledged. The authors also thank Matteo Geminiani, Raffaele Gorlezza and Gregorio Sanchez Arevalo for their help in performing experimental tests along different time steps of the project, in partial fulfilment of the requirements to obtain their MScEng degrees.Ferrara, L.; Krelani, V.; Moretti, F.; Roig-Flores, M.; Serna Ros, P. (2017). Effects of autogenous healing on the recovery of mechanical performance of High Performance Fibre Reinforced Cementitious Composites (HPFRCCs): Part 1. Cement and Concrete Composites. 83:76-100. doi:10.1016/j.cemconcomp.2017.07.010S761008

Conservation laws of semidiscrete canonical Hamiltonian equations

There are many evolution partial differential equations which can be cast into Hamiltonian form. Conservation laws of these equations are related to one-parameter Hamiltonian symmetries admitted by the PDEs. The same result holds for semidiscrete Hamiltonian equations. In this paper we consider semidiscrete canonical Hamiltonian equations. Using symmetries, we find conservation laws for the semidiscretized nonlinear wave equation and Schrodinger equation.Comment: 19 pages, 2 table

Interaction of ballistic quasiparticles and vortex configurations in superfluid He3-B

The vortex line density of turbulent superfluid He3-B at very low temperature is deduced by detecting the shadow of ballistic quasiparticles which are Andreev reflected by quantized vortices. Until now the measured total shadow has been interpreted as the sum of shadows arising from interactions of a single quasiparticle with a single vortex. By integrating numerically the quasi-classical Hamiltonian equations of motion of ballistic quasiparticles in the presence of nontrivial but relatively simple vortex systems (such as vortex-vortex and vortex-antivortex pairs and small clusters of vortices) we show that partial screening can take place, and the total shadow is not necessarily the sum of the shadows. We have also found that it is possible that, upon impinging on complex vortex configurations, quasiparticles experience multiple reflections, which can be classical, Andreev, or both.Comment: To appear in Phys Rev

OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level

Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu

Hyperextended Scalar-Tensor Gravity

We study a general Scalar-Tensor Theory with an arbitrary coupling funtion $\omega (\phi )$ but also an arbitrary dependence of the ``gravitational constant'' $G(\phi )$ in the cases in which either one of them, or both, do not admit an analytical inverse, as in the hyperextended inflationary scenario. We present the full set of field equations and study their cosmological behavior. We show that different scalar-tensor theories can be grouped in classes with the same solution for the scalar field.Comment: latex file, To appear in Physical Review