Theory, codes, and numerical simulation of heat transport in multicomponent systems

Heat transport is a topic that is fundamental in many fields, from materials engineering to planetary models. The calculation of the thermal transport coefficient with the Green-Kubo theory in multicomponent fluids, especially in ab-initio simulations, had a severe data analysis issue that this work solved. In this thesis, we derive the entire theory and data analysis framework for the multicomponent Green-Kubo. Then we show the computer codes we developed, allowing the user to apply the approach previously derived. We believe that in science, replicability and reproducibility are essential requirements. Every new technique must come with an open-source and reliable implementation. In the end, we demonstrate a significant application to superionic ammonia, fundamental to understanding the behavior of icy giant planets like Uranus and Neptune, providing an estimate for the thermal transport coefficient

Die gute alte Fruchtfolge als Bekämpfungsmethode gegen den Maiswurzelbohrer (Diabrotica virgifera virgifera LeConte)

Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), the western corn rootworm (WCR), is an immigrant from North America and one of the top ten global agricultural pest species. Within the last 15 years, WCR invaded Europe at 3 focal points, and has been steadily extending its domain soon threatening commercial maize production. After the first detection in Switzerland in 2000 near Lugano, careful observations by pheromone trap monitoring of this quarantine organism have been realized. Experiences with WCR whose populations dynamics are incompletely understood, have also been studied by installing a continuous maize field comparing population dynamics with rotated maize fields in the immediate surroundings. Our experiences with WCR populations in the Swiss territory are here briefly summarized: 1. Mandatory crop rotation in the canton Ticino slowed spread of WCR significantly. WCR infestations north of the main Alpine mountain chain were rare and eradicated by crop rotation. 2. In a continuous maize cropping system population of WCR can reach economic damage level, but can also be confined by unknown factors 3. Switzerland with its rigorous crop rotation program may serve as an example of farsighted WCR management preserving environment and saving money

Theory and Numerical Simulation of Heat Transport in Multicomponent Systems

The thermal conductivity of classical multicomponent fluids is seemingly affected by the intrinsic arbitrariness in the definition of the atomic energies, and it is ill conditioned numerically, when evaluated from the Green-Kubo theory of linear response. To cope with these two problems, we introduce two new concepts: a convective invariance principle for transport coefficients, in the first case, and multivariate cepstral analysis, in the second. A combination of these two concepts allows one to substantially reduce the noise affecting the estimate of the thermal conductivity from equilibrium molecular dynamics, even for one-component systems

Heat Transport in Insulators from Ab Initio Green-Kubo Theory

The Green-Kubo theory of thermal transport has long been considered incompatible with modern simulation methods based on electronic-structure theory, because it is based on such concepts as energy density and current, which are ill-defined at the quantum-mechanical level. Besides, experience with classical simulations indicates that the estimate of heat-transport coefficients requires analyzing molecular trajectories that aremore than one order of magnitude longer than deemed feasible using ab initio molecular dynamics. In this paper we report on recent theoretical advances that are allowing one to overcome these two obstacles. First, a general gauge invariance principle has been established, stating that thermal conductivity is insensitive to many details of the microscopic expression for the energy density and current from which it is derived, thus permitting to establish a rigorous expression for the energy flux from Density-Functional Theory, from which the conductivity can be computed in practice. Second, a novel data analysis method based on the statistical theory of time series has been proposed, which allows one to considerably reduce the simulation time required to achieve a target accuracy on the computed conductivity. These concepts are illustrated in detail, starting from a pedagogical introduction to the Green-Kubo theory of linear response and transport, and demonstrated with a few applications done with both classical and quantum-mechanical simulation methods

Verification of a Synthesized Method for the Calculation of Low-Level Climatological Wind Fields Using a Mesoscale Boundary-Layer Model

Low-level climatological wind fields over the La Plata River region of South America are synthesized with a dry, hydrostatic mesoscale boundary-layer numerical model. The model is forced at the upper boundary with the 1200 UTC local radiosonde observations and at the lower boundary with a land-river differential heating function defined from the daily meteorological observations of the region. The climatological wind field is defined as the mean value of a series of individual daily forecasts, employing two methods. The simplified method considers a 192-member ensemble (16 wind directions and 12 wind-speed classes at the upper boundary). Each member has a probability of occurrence that is determined from the 1959-1984 observations; the daily method uses a total of 3,248 days with available data during the same period. In both methods each realization is a daily forecast from which the mean wind distributions at 0300, 0900, 1500 and 2100 local standard time are calculated and compared to the observations of five meteorological stations in the region. The validation of the climatological wind fields for both methods is evaluated by means of the root-mean-square error of the wind-direction frequency distribution and mean wind speed by wind sector. The results obtained with the two methods are similar, and the errors in wind speed are always smaller than those in wind direction. The combined errors of wind direction and wind speed show that the ensemble method is outperformed by the daily method, on average by meteorological station in only one out of five of them, and on average by the time of the day in only one out of 4 h. The conclusion of the study is that the ensemble method is an appropriate methodology for determining high resolution, low-level climatological wind fields, with the boundary-layer model applied to a region with a strong diurnal cycle of surface thermal contrast. The proposed methodology is of particular utility for synthesizing wind fields over regions with limited meteorological observations, since the 192-member matrix can be easily defined with few observing points, as well as in the case of relatively incomplete records.Fil: Berri, Guillermo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; ArgentinaFil: Galli Nuin, Jorgelina Susana. Universidad de Buenos Aires; ArgentinaFil: Sraibman, Laura. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bertossa, German. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; Argentin

Gambling in a remote Aboriginal setting - the good, the bad and the ugly

In 2009 the Ceduna Koonibba Aboriginal Health Service, an Indigenous-specific service, and Statewide Gambling Therapy Service joined together to investigate the impact that gambling was having on the Aboriginal people living in this region. Both organisations were funded through the state-based Office for Problem Gambling to provide gambling intervention. A number of signs indicate that the community development approach has proven effective. Towards the end of the first year of the project six people signed up for one-on-one therapy to address gambling; a small group of women met regularly to learn more about how to overcome gambling and provide support to each other. In general, there has been a notable improvement in the level of engagement with the program amongst health and welfare workers in the town, with the Project Officers regularly meeting with staff across agencies

First-Stage Development of the Pitjantjatjara Translation of the World Health Organization’s Alcohol, Smoking and Substance Involvement Screening Test (ASSIST)

Substance use is a leading contributor to global disease, illness and death. Compared with non-Indigenous Australians, Aboriginal and Torres Strait Islander Australians are at an increased risk of substance-related harms due to the experience of additional social, cultural, and economic factors. While preventive approaches, including screening and early interventions are promising, currently there are limited options available to healthcare workers that are culturally appropriate for use in Aboriginal and Torres Strait Islander populations. Therefore, the aim of this research was to translate and culturally adapt the World Health Organization endorsed, Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) into Pitjantjatjara. This paper first describes the process of translation and adaptation of the instrument (Phase 1). The process of focus-group testing the translated instrument for accuracy and cultural appropriateness is also discussed (Phase 2). Key findings from both phases are presented in the context of how the research team worked with key stakeholders in the community to identify facilitators and work through barriers to implementation. The findings from this paper will be used to inform the development of a digital, app-based version of the instrument for the purposes of pilot-testing and validation

Initializing a Mesoscale Boundary-Layer Model with Radiosonde Observations

A mesoscale boundary-layer model is used to simulate low-level regional wind fields over the La Plata River of South America, a region characterized by a strong daily cycle of land–river surface-temperature contrast and low-level circulations of sea–land breeze type. The initial and boundary conditions are defined from a limited number of local observations and the upper boundary condition is taken from the only radiosonde observations available in the region. The study considers 14 different upper boundary conditions defined from the radiosonde data at standard levels, significant levels, level of the inversion base and interpolated levels at fixed heights, all of them within the first 1500 m. The period of analysis is 1994–2008 during which eight daily observations from 13 weather stations of the region are used to validate the 24-h surface-wind forecast. The model errors are defined as the root-mean-square of relative error in wind-direction frequency distribution and mean wind speed per wind sector. Wind-direction errors are greater than wind-speed errors and show significant dispersion among the different upper boundary conditions, not present in wind speed, revealing a sensitivity to the initialization method. The wind-direction errors show a well-defined daily cycle, not evident in wind speed, with the minimum at noon and the maximum at dusk, but no systematic deterioration with time. The errors grow with the height of the upper boundary condition level, in particular wind direction, and double the errors obtained when the upper boundary condition is defined from the lower levels. The conclusion is that defining the model upper boundary condition from radiosonde data closer to the ground minimizes the low-level wind-field errors throughout the region.Facultad de Ciencias Astronómicas y Geofísica

Effect of the Gene doublesex of Anastrepha on the Somatic Sexual Development of Drosophila

8 pages, 4 figures and 2 tables.[Background] The gene doublesex (dsx) is at the bottom of the sex determination genetic cascade and is transcribed in both sexes, but gives rise to two different proteins, DsxF and DsxM, which impose female and male sexual development respectively via the sex-specific regulation of the so-called sexual cyto-differentiation genes. The present manuscript addressed the question about the functional conservation of the tephritid Anastrepha DsxF and DsxM proteins to direct the sexual development in Drosophila (Drosophilidae).[Methodology] To express these proteins in Drosophila, the GAL4-UAS system was used. The effect of these proteins was monitored in the sexually dimorphic regions of the fly: the foreleg basitarsus, the 5th, 6th and 7th tergites, and the external terminalia. In addition, we analysed the effect of Anastrepha DsxF and DsxM proteins on the regulation of Drosophila yolk protein genes, which are expressed in the fat body of adult females under the control of dsx.Conclusions The Anastrepha DsxF and DsxM proteins transformed doublesex intersexual Drosophila flies into females and males respectively, though this transformation was incomplete and the extent of their influence varied in the different sexually dimorphic regions of the adult fly. The Anastrepha DsxF and DsxM proteins also behaved as activators and repressors, respectively, of the Drosophila yolk protein genes, as do the DsxF and DsxM proteins of Drosophila itself. Finally, the Anastrepha DsxF and DsxM proteins were found to counteract the functions of Drosophila DsxM and DsxF respectively, reflecting the normal behaviour of the latter proteins towards one another. Collectively, these results indicate that the Anastrepha DsxF and DsxM proteins show conserved female and male sex-determination function respectively in Drosophila, though it appears that they cannot fully substitute the latter's own Dsx proteins. This incomplete function might be partly due to a reduced capacity of the Anastrepha Dsx proteins to completely control the Drosophila sexual cyto-differentiation genes, a consequence of the accumulation of divergence between these species resulting in the formation of different co-adapted complexes between the Dsx proteins and their target genes.This work was financed by grant BFU2005-03000 awarded to L. Sa´nchez by the D.G.I.C.Y.T. (Spanish Government).Peer reviewe