Structure of the Effective Potential in Nonrelativistic Chern-Simons Field Theory

We present the scalar field effective potential for nonrelativistic self-interacting scalar and fermion fields coupled to an Abelian Chern-Simons gauge field. Fermions are non-minimally coupled to the gauge field via a Pauli interaction. Gauss's law linearly relates the magnetic field to the matter field densities; hence, we also include radiative effects from the background gauge field. However, the scalar field effective potential is transparent to the presence of the background gauge field to leading order in the perturbative expansion. We compute the scalar field effective potential in two gauge families. We perform the calculation in a gauge reminiscent of the $R_\xi$-gauge in the limit $\xi\rightarrow 0$ and in the Coulomb family gauges. The scalar field effective potential is the same in both gauge-fixings and is independent of the gauge-fixing parameter in the Coulomb family gauge. The conformal symmetry is spontaneously broken except for two values of the coupling constant, one of which is the self-dual value. To leading order in the perturbative expansion, the structure of the classical potential is deeply distorted by radiative corrections and shows a stable minimum around the origin, which could be of interest when searching for vortex solutions. We regularize the theory with operator regularization and a cutoff to demonstrate that the results are independent of the regularization scheme.Comment: 24 pages, UdeM-LPN-TH-93-185, CRM-192

Poisonous plants for cattle in Colombia: research perspectives

Even though Colombian cattle-farming makes an important contribution to the national economy it also has great potential for growth; however, this activity is carried out in areas where animals may become naturally exposed to poisonous plants, affecting their health and production. It is recognised that some plants may damage the livestock sector in countries placing an important emphasis on cattle-rearing. Such problem has received scarce attention from academic research in Colombia, and the efforts made to do so date from the 1930s, 1940s, 1970s and 1980s without having had continuity. Many of the studies done in Colombia have been orientated towards establishing nitrate and cyanogenic glycoside content, ignoring other toxic metabolites. Likewise, certain vegetal species which can cause poisoning have not been fully studied, thereby hampering their management and treatment. It is thus important that studies are carried out in greater depth in Colombia concerning poisonous plants affecting livestock. A methodology is thus proposed which includes a search for initial information about suspicious plants, reproducing such poisoning experimentally (selecting the animal species, route, presentation and administration time, and evaluating effects) and searching for the chemical responsible for causing the poisoning. All these aspects are dealt with in the present review.Además de un gran potencial de crecimiento, la ganadería bovina colombiana tiene un importante aporte a la economía nacional. Esta actividad se desarrolla en áreas donde los animales pueden exponerse naturalmente a plantas tóxicas, afectando su salud y producción. En países con una importante vocación ganadera se reconocen las plantas que pueden menoscabar el sector pecuario. En Colombia, escasamente ha sido estudiada esta problemática y los esfuerzos por hacerlo datan de las décadas de 1930, 1940, 1970 y 1980, sin que haya habido continuidad en los mismos. Muchos de los estudios realizados en el país han estado orientados a establecer el contenido de nitratos y glucósidos cianogénicos, ignorando otros metabolitos tóxicos. Así mismo, existen intoxicaciones por ciertas especies de vegetales que no han sido plenamente estudiadas, dificultando su manejo y tratamiento. Es importante que en el país se investigue con mayor profundidad sobre las plantas tóxicas de interés pecuario y para ello se propone una metodología que incluye selección de la planta sospechosa, reproducción experimental de la intoxicación (elección de la especie animal, vía, presentación y tiempo de administración y evaluación de efectos) y búsqueda de principios responsables de causar la intoxicación; estos aspectos se abordan en la presente revisión.Facultad de Ciencias Veterinaria

Poisonous plants for cattle in Colombia: research perspectives

Even though Colombian cattle-farming makes an important contribution to the national economy it also has great potential for growth; however, this activity is carried out in areas where animals may become naturally exposed to poisonous plants, affecting their health and production. It is recognised that some plants may damage the livestock sector in countries placing an important emphasis on cattle-rearing. Such problem has received scarce attention from academic research in Colombia, and the efforts made to do so date from the 1930s, 1940s, 1970s and 1980s without having had continuity. Many of the studies done in Colombia have been orientated towards establishing nitrate and cyanogenic glycoside content, ignoring other toxic metabolites. Likewise, certain vegetal species which can cause poisoning have not been fully studied, thereby hampering their management and treatment. It is thus important that studies are carried out in greater depth in Colombia concerning poisonous plants affecting livestock. A methodology is thus proposed which includes a search for initial information about suspicious plants, reproducing such poisoning experimentally (selecting the animal species, route, presentation and administration time, and evaluating effects) and searching for the chemical responsible for causing the poisoning. All these aspects are dealt with in the present review.Además de un gran potencial de crecimiento, la ganadería bovina colombiana tiene un importante aporte a la economía nacional. Esta actividad se desarrolla en áreas donde los animales pueden exponerse naturalmente a plantas tóxicas, afectando su salud y producción. En países con una importante vocación ganadera se reconocen las plantas que pueden menoscabar el sector pecuario. En Colombia, escasamente ha sido estudiada esta problemática y los esfuerzos por hacerlo datan de las décadas de 1930, 1940, 1970 y 1980, sin que haya habido continuidad en los mismos. Muchos de los estudios realizados en el país han estado orientados a establecer el contenido de nitratos y glucósidos cianogénicos, ignorando otros metabolitos tóxicos. Así mismo, existen intoxicaciones por ciertas especies de vegetales que no han sido plenamente estudiadas, dificultando su manejo y tratamiento. Es importante que en el país se investigue con mayor profundidad sobre las plantas tóxicas de interés pecuario y para ello se propone una metodología que incluye selección de la planta sospechosa, reproducción experimental de la intoxicación (elección de la especie animal, vía, presentación y tiempo de administración y evaluación de efectos) y búsqueda de principios responsables de causar la intoxicación; estos aspectos se abordan en la presente revisión.Facultad de Ciencias Veterinaria

Formation, compression and surface melting of colloidal clusters by active particles

We demonstrate with experiments and numerical simulations that the structure and dynamics of a suspension of passive particles is strongly altered by adding a very small (<1%) number of active particles. With increasing passive particle density, we observe first the formation of dynamic clusters comprised of passive particles being surrounded by active particles, then the merging and compression of these clusters, and eventually the local melting of crystalline regions by enclosed active particles. © The Royal Society of Chemistry 2015

The semantic effects of verb raising and its consequences in second language grammars

This article considers whether highly proficient second language speakers of English can distinguish meaning contrasts associated with constructions where there is a raising be, and constructions where there is a non-raising thematic verb, as illustrated in the difference between (1a) and (1b): 1a. Kim is reading a novel (`event-in-progress/existential ? interpretation

Silicon-based three-dimensional microstructures for radiation dosimetry in hadrontherapy

In this work, we propose a solid-state-detector for use in radiation microdosimetry. This device improves the performance of existing dosimeters using customized 3D-cylindrical microstructures etched inside silicon. The microdosimeter consists of an array of micro-sensors that have 3D-cylindrical electrodes of 15 μm diameter and a depth of 5 μm within a silicon membrane, resulting in a well-defined micrometric radiation sensitive volume. These microdetectors have been characterized using an 241Am source to assess their performance as radiation detectors in a high-LET environment. This letter demonstrates the capability of this microdetector to be used to measure dose and LET in hadrontherapy centers for treatment plan verification as part of their patient-specific quality control program

Solving sudoku's by evolutionary algorithms with pre-processing

This paper handles the popular Sudoku puzzle and studies how to improve evolutionary algorithm solving by first pre-processing Sudoku solving with the most common known solving methods. We found that the pre-processing solves some of the easiest Sudoku’s so we do not even need other methods. With more difficult Sudoku’s the pre-processing reduce the positions needed to solve dramatically, which means that evolutionary algorithm finds the solution much faster than without the pre-processing.fi=vertaisarvioitu|en=peerReviewed

Deep eutectic solvents: green solvents for the removal of degraded gelatin on cellulose nitrate cinematographic films

Cellulose nitrate (CN) has been used in the past as support for photographic negatives and cinematographic films. This material is particularly unstable and can undergoes severe degradation due to thermal, photocatalytic and hydrolytic loss of nitro groups from the lateral chain. Thus, to prevent the disappearance of the movies, their scanning and digitalization become a priority. However, CN bases degradation may prevent the scanning of the films. The decrease in pH, for instance, lowers the viscosity of gelatin, which becomes softer. This causes the formation of gelatin residues which stick on the back of the superimposed frames inside the reels creating a deposit. Traditional approaches to clean gelatin residues from the surface of CN bases include the mechanical removal with scalpels and the use of organic solvents (such as isopropyl alcohol). However, these methods are either slow and ineffective or could potentially damage the degraded CN supports. To overcome these drawbacks, we have evaluated the performance of three choline chloride and betaine-based Deep Eutectic Solvent (DES) formulations as alternative for the removal of gelatine residues from CN supports. These solvents are inexpensive (when compared to traditional solvents), easy to prepare, green (non volatile, safe towards the operators and the environment, and potentially recyclable), non flammable and have been previously proposed for the extraction of proteinaceous materials, but their use for the restoration of photographic negatives or cinematographic films has not been reported yet. Selected areas over the frames of a real deteriorated CN cinematographic film were cleaned comparing the DES performances with the ones obtained using isopropyl alcohol as an example of a traditional method. In particular, the tested DES formulations showed superior cleaning power compared to isopropyl alcohol and, at the selected application times, resulted capable to remove the gelatin residues without affecting the CN film supports. Graphical abstract: [Figure not available: see fulltext.]