An investigation into the feasibility of utilizing pneumatic ultrasonic devices coupled with pneumatic fracturing in enhancing removal of volatile organic compounds from soils

A bench scale investigation was conducted in a Plexiglass ™ Test cell 1 foot square by 2 feet in height, packed with 400 mesh sand to a density of 100 lb. /ft3. The sand was contaminated with a mixture of 10% ethanol and 90% water by weight having a total weight of 11.1 pounds, before it was packed in the test cell. A geotextile 1/2 inch thick was used as a simulated fracture and was placed 3 inches from the bottom of the tank. A siren and a whistle were tested in this fracture. The data were divided into a transient, two phase flow region, and a falling rate region similar to drying theory analysis. Free moisture versus time data showed a 39.1% improvement for the siren and a 412.4% improvement for the whistle in the transient region, and a 69% improvement for the siren and a 455 % improvement for the whistle in the falling rate region. Concentration of ethanol versus time data showed a 62.9% improvement for the siren in the transient region and no comparison was established for the whistle. A 192.0% improvement for the siren and a 931.4 % improvement for the whistle were measured in the falling rate region. The average time to reach asymptotic value of 0.01 free moisture with the siren was reduced by 37% and greater than 74.3% with the whistle. The average time to reach an ethanol concentration of 1 ppmv was reduced by greater than 41.3% with the siren and by greater than 74% with the whistle

¿Los errores en las asignaciones de procedencia llevan a subestimar la biodiversidad de las aguas subterráneas?

Individuos de ciertos taxa (e.g., hidrácaros y crustáceos) que pueblan aguas subterráneas son coleccionados ocasionalmente en ríos y arroyos y asignados erróneamente al hábitat bentónico. Esto sucede a pesar de su morfología típica de estigobiontes o habitantes del medio subterráneo. Analizo aquí algunas causas de estas inesperadas colecciones. A partir del conocimiento del intercambio de agua subterránea y superficial y de su impacto en la ecología del hábitat acuático, remarco su importancia para el estudio de la biodiversidad acuática.Individuals of certain taxa (e.g., water mites and crustaceans) collected from streams and rivers are often assigned to a surficial benthic origin when the animals clearly display subterranean morphological characteristics. This paper addresses reasons for these errors and proposes ways to minimize such mistakes when sampling.Fil: Fernandez, Hugo Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin

Differential activities of glutathione s-transferase isoenzymes in strains of fasciola hepatica susceptible and resistant to triclabendazole

Fasciolosis, a parasitic zoonosis of intrahepatic location, is caused by the trematode Fasciola hepatica. Its control is mainly based on the use of the anthelminthic Triclabendazole (TCBZ). The indiscriminate use of this drug has favored the development of anthelmintic resistance. The Glutation S-Transferases (GSTs) are multifunctional enzymes involved in the detoxification of xenobiotics and endogenous compounds using conjugation with endogenous glutathione. Recently, it has been shown an active participation of this family of enzymes in the detoxification of TCBZ related to the phenomenon of resistance. In F. hepatica, eight isoenzymes of the GST are present. Since it is well known that different isoenzymes do not necessarily have the same metabolic activity, this study evaluated the cytosolic activity of mu and pi GST isoenzymes in TCBZ resistant (Sligo and Oberon strains) and TCBZ susceptible (Cullompton strains) of F. hepatica. The results obtained in this study confirm that, although both isoenzymes are involved in different processes of detoxification in F. hepatica, only the GSTmu isoenzyme is involved in the manifestation of resistance to TCBZ.Fil: Fernandez, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Ortiz Oblitas P.. Universidad Nacional de Cajamarca; PerúFil: Solana, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina. Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Cientifíca y Tecnológica; ArgentinaFil: Solana, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentin

Finite element analysis of crenulated and non-crenulated hominid molars : A functional hypothesis explaining the adaptive significance of molar crenulation

Objectives The occlusal surface of many mammalian teeth has grooves that have been collectively called crenulations. The evolutionary significance of this trait is unknown, but it has been associated with a hard diet. It has not been explained, however, why crenulated molars may present an increased mechanical resistance. The objective of this study was to determine whether a crenulated surface dissipate mechanical stress more efficiently than a smooth one. Materials and methods Using mu CT scans we built 3D models of lower second molars from Homo, Pan, Gorilla, and Pongo. The crenulated models from Homo and Pongo were modified to remove crenulations. Finite element analysis was used to determine the distribution of mechanical stress in all the models when a vertical force was applied. Results The results show that crenulated molars have a distinctive pattern of mechanical stress, namely the stress is higher in the valleys than in the crests of the crenulations. In non-crenulated molars, mechanical stress is more homogeneously distributed. Highly crenulated molars of orangutans show the smallest values of mean stress among the compared species. Artificially removing crenulations results in more homogeneous distribution of stresses and increased mean stress values. Conclusions Molar crenulations may increase molar resistance by canalizing mechanical stress from the tip to the base of the cusps. The overall cusp shape also influences the distribution of stress. This mechanism may be a functional hypothesis to explain the association between crenulated molars and mechanically demanding diets.Peer reviewe

Electrification and Educational Outcomes in Rural Peru

We study the effects of electrification on educational outcomes in Peru by taking advantage of a program that rapidly increased electricity coverage in rural areas. Using household survey panel data from 2007-2010, we document that: i) girls living in treated districts are more likely to be enrolled in school, and this effect is larger among younger girls; ii) this positive effect on female enrollment does not translate into higher attendance rates; iii) households in treated areas spend more money on younger girls' education. In addition, we use school-level panel data from 2007-2012 on Math and Reading test scores to show that treatment is associated with a reduction in learning. But, among treated schools, longer treatment exposure increases scores in Reading for boys and girls; and improves performance in Math, only among boys. Finally, our estimates are robust to controlling for other confounding interventions

Wayfinding across ocean and tundra: what traditional cultures teach us about navigation

Research on human navigation by psychologists and neuroscientists has come mainly from a limited range of environments and participants inhabiting western countries. By contrast, numerous anthropological accounts illustrate the diverse ways in which cultures adapt to their surrounding environment to navigate. Here, we provide an overview of these studies and relate them to cognitive science research. The diversity of cues in traditional navigation is much higher and multimodal compared with navigation experiments in the laboratory. It typically involves an integrated system of methods, drawing on a detailed understanding of the environmental cues, specific tools, and forms part of a broader cultural system. We highlight recent methodological developments for measuring navigation skill and modelling behaviour that will aid future research into how culture and environment shape human navigation

Crowding under diverse distance criteria for niche formation in multimodal optimization

Niche formation allows evolutionary algorithms to be used when the location and maintenance of multiple solutions appertaining to diverse areas of the phenotypic space is required. Consequently the application field can be extended to multiobjective optimization, simulation of complex systems and multimodal function optimization. In this later case a conventional evolutionary algorithm tends to group the final population around the fittest individual. Thus, other areas of interest in the search process are lost. Niching methods permits the maintenance of solutions located around these areas of interest. This contribution briefly describe problems preventing niche formation in conventional genetic algorithms, a crowding method for niche formation and analysis of results when optimizing two multimodal functions.Facultad de Informátic