Composting to control the leaf-cutting ant atta cephalotes l. (hymenoptera: formicidae)

Leaf-cutting ants, Atta and Acromyrmex, are the most important defoliating herbivores in the tropics. In this study, field assays were conducted to compare the effects of two non chemical methods on survival and activity of Atta cephalotes (Formicidae: Myrmicinae) nests. A total of 83 A. cephalotes active nests were randomly assigned to one of three treatments: 1) compostable material introduced and processed into the soil of ant nests; 2) conventional mechanical mixing of the ant nests soil; 3) untreated ant nests. After three months the percentages of dead nets were 26.5, 9.63 and 3.61 using manure compost, mechanical, and control, respectively. A repeated measurement analysis of variance showed significant difference between ant colonies for both treatments, composted and mechanical mixing, with respect to the untreated treatment, given the disruption of foraging trails, mound openings, chambers and tunnels. The strongest effect was observed with the compostable material. Based on its effect on A. cephalotes (Formicidae: Myrmicinae) nests and potential soil enrichment, compostable treatment could be a sustainable and ecologically sound management practice if proper conditions are given at the site. Las hormigas cortadoras de hojas, Atta y Acromyrmex, son los herbívoros más importantes en los trópicos. En este estudio se comparan los efectos de dos métodos no químicos sobre la sobrevivencia y actividad de nidos de Atta cephalotes (Formicidae:Myrmicinae). Un total de 83 nidos activos de A. cephalotes fueron asignados de forma aleatoria a uno de tres tratamientos: 1) incorporación de un material compostable al suelo; 2) remoción y mezcla de la capa superficial del suelo (método convencional) y 3) placebo o control (sin tratamiento). Después de tres meses, los porcentajes de nidos eliminados con cada uno de los tratamientos fueron 26,5; 9,6; y 3,6; respectivamente. Un análisis de varianza de medidas repetidas mostró una diferencia significativa entre las colonias de hormigas sometidas a los tratamientos compostado y remoción mecánica en relación con el placebo. Esto debido a la destrucción de las pistas de forrajeo, de las aberturas, cámaras y túneles. Sin embargo, el más fuerte efecto fue observado con el compostado. Basado en estos resultados sobre los nidos de A. cephalotes y su efecto potencial de enriquecer el suelo, el tratamiento compostado puede representar una práctica sustentable y ecológicamente amigable en el control de hormigueros de Atta

Secuencia didáctica para la producción de texto argumentativo (ensayo), en estudiantes de grado once de la institución educativa Inem Felipe Perez de Pereira

Esta propuesta de investigación tiene como objetivo valorar el diseño e implementación de una estrategia de enseñanza y aprendizaje denominada secuencia didáctica, para el abordaje de uno de los aspectos más importantes en la enseñanza de la lengua, como es el reconocimiento y uso del El propósito de esta investigación, es presentar los resultados de una secuencia didáctica en la cual se explicita la organización superestructural del texto argumentativo utilizada como estrategia de enseñanza y aprendizaje, para la producción de ensayos basados en argumentos, en un grupo de estudiantes de grado once de la Institución Educativa INEM Felipe Pérez de la ciudad de Pereira.The purpose of this research study, is to present the results of a didactic sequence, in which it is explicit the super structural organization of the argumentative text used as a teaching and learning strategy, to the production of essays based on arguments, in a group of eleventh graders from INEM Felipe Perez institute from Pereira city

Population Density Estimates of the Montezuma Quail (Cyrtonyx montezumae) in West Texas

In Texas, USA, populations of Montezuma quail (Cyrtonyx montezumae) can be found scattered across mountain ranges in the Trans-Pecos region, including the Davis and Guadalupe, and farther east into the Edwards Plateau region. Abundance and distribution information to assist land managers in the enhancement of Montezuma quail populations is scarce due to the species’ secretive behavior and unknown abundance. We aimed to provide population density indices to fill this information gap by using a search path technique. We searched for quail in the winter of 2018–2019 in West Texas at 6 study sites: 5 private ranches and Elephant Mountain Wildlife Management Area (EMWMA). We chose survey locations based on previous quail sightings and our perception that an area contained suitable Montezuma quail habitat. We searched small watersheds using at least 2 dogs while walking along contours. The average search path length was 1.82 km (range = 0.80–4.30). We produced a hexagonal grid with a cell size of 1 ha such that no pair of coveys can be encountered on the same cell. The area associated to each search was the sum of the areas of all hexagonal cells intersected by the search path. For density index, we directly used the definition of density (birds encountered divided by area searched). Mean covey density was 1.51 ± 2.53 (± standard error) coveys/km2 (range = 0.50–4.17), although abundance data were overdispersed. The highest density estimate was for EMWMA. Mean covey size was 6.55 ± 0.61 birds/covey. These data yielded an estimate of 10.07 ± 17.45 birds/km2. As we did not account for imperfect detection, our quail density estimates are lower bounds of actual density. These quail density estimates are lower than estimates for Arizona, USA but higher than density estimates reported for the Edwards Plateau and central Mexico. A prevailing concern regarding the harvest of the Montezuma quail among some wildlife professionals and the public in Texas is the perception that Montezuma quail are scarce. Therefore, our density estimates suggest that abundance of Montezuma quail in West Texas may not be as low as perceived and that Montezuma quail populations may be appropriate for an open hunt season

The Network of Global Corporate Control

The structure of the control network of transnational corporations affects global market competition and financial stability. So far, only small national samples were studied and there was no appropriate methodology to assess control globally. We present the first investigation of the architecture of the international ownership network, along with the computation of the control held by each global player. We find that transnational corporations form a giant bow-tie structure and that a large portion of control flows to a small tightly-knit core of financial institutions. This core can be seen as an economic “super-entity” that raises new important issues both for researchers and policy makers

Adoption of a surrogate artificial queen in a colony of Atta cephalotes (L.) (Hymenoptera: Formicidae) in Colombia

In nature, Atta cephalotes (L.) is a monogynous species. Each colony has a single, permanent queen fed and protected by thousands of sterile workers. At death the queen colony practically disappears. Recently a colony established eight years in the International Center for Tropical Agriculture (CIAT), Colombia, loses the queen being orphaned by three months. Starting from the idea of whether this colony could take a surrogate queen, we collect a field young nest of A. cephalotes, which donated its queen to the orphan colony. Overall, there was a slight aggression among workers without attacking the surrogate queen, which was adopted by the orphan colony. Five months later, surrogate queen were still alive and there was presence of larvae and pupae. The results show that artificial colony of A. cephalotes, after a period of orphanhood, accept surrogate queen and remain stable and active

Effects of High Heeled Gait on Knee Joint Mechanics

Numerous women wear high heeled shoes, whether it be a professional attire, part of an outfit for a ballroom gala, or just casual day to day wear. Often, the high heel of choice in these situations is the stiletto. These shoes adversely affect natural gait and have the potential to alter joint mechanics in the knee during gait. PURPOSE: This study is designed to analyze the impacts of wearing high heels, and if it puts the user at a higher risk of a degenerative condition with repeated use. We hypothesized that all of our dependent variables would see a significant increase when wearing high heels. METHODS: For the scope of this project, we narrowed our analysis to the knee joint and ground reaction force loading rate. We designed this study using a Cortex motion capture system along with force plates to conduct a series of experiments. Six college aged women with experience walking in high heels and no injury or condition that would adversely affect normal gait were selected to participate in motion analysis experiments. There are 4 trials conducted in total, which include walking, and performing a lateral stepping motion to simulate dancing, each under barefoot and high heeled conditions. The variables we set out to analyze include knee compressive force, flexion moment, varus and valgus moments, ground loading rate, and EMG peak activity for muscles including medial and lateral gastrocnemius, vastus lateralis, and biceps femoris. All force data was normalized by body weight to compare across participants. RESULTS: After processing the data and performing a statistical analysis using a paired T-test with significance of α \u3c 0.05, we found the variables with a significant difference between barefoot and high heels is the knee compressive force during gait (P = 0.001) and loading rate from the ground reaction force (P = 0.009). CONCLUSION: This indicates that wearing high heels can significantly increase knee joint loading

Field and Model Study to Define Baseline Conditions of Beached Oil Tar Balls along Florida’s First Coast

Anecdotal data are currently the best data available to describe baseline conditions of beached oil tar balls on Florida’s First Coast beaches. This study combines field methods and numerical modeling to define a data-driven knowledge base of oil tar ball baseline conditions. Outcomes from the field study include an established methodology for field data collection and laboratory testing of beached oil tar balls, spatial maps of collected samples and analysis of the data as to transport/wash-up trends. Archives of the electronic data, including GPS locations and other informational tags, and collected samples are presented, as are the physical and chemical analyses of the collected samples. The thrust of the physical and chemical analyses is to differentiate the collected samples into highly suspect oil tar balls versus false/non-oil tar ball samples. The numerical modeling involves two-dimensional hydrodynamic simulations of astronomic tides. Results from the numerical modeling include velocity residuals that show ebb-dominated residual currents exiting the inlet via an offshore, counter-rotating dual-eddy system. The tidally derived residual currents are used as one explanation for the observed transport trends. The study concludes that the port activity in the St. Johns River is not majorly contributing to the baseline conditions of oil tar ball wash-up on Florida’s First Coast beaches

Adecuación tecnológica de la máquina de inyección de plástico del laboratorio de mecánica, de la Universidad Tecnológica de Pereira

Este proyecto muestra la adecuación tecnológica de la máquina de inyección de plástico del laboratorio de mecánica de la Universidad Tecnológica de Pereira. Como parte inicial del trabajo realizado se muestran los diferentes diseños de hardware electrónico de tal manera que la adecuación realizada trabaje en conjunto y de manera paralela a los dispositivos eléctricos ya instalados. Dentro de los dispositivos instalados se cuenta con software de Supervisión, Control y Adquisición de Datos (Supervisory Control And Data Acquisition) SCADA el cual interactúa con la máquina a través de una comunicación serial con un controlador lógico programable S7-200 Siemens este dispositivo es el intermediario entre el SCADA y las diferentes variables del proceso de modelado de plástico. El sistema SCADA Registra las temperaturas del tubo de plastificación, permite ajustar el Set Point de temperatura requeridos, tiempos asociados al proceso de plastificación, además permite seleccionar el modo de operación de la máquina entre manual y automático, también se puede ajustar el número de ciclos en el modo de operación automática.This project shows the technological adequacy of plastic injection machine, of the mechanics laboratory in the Technological University of Pereira. As initial part of this work, shows the different designs of electronic hardware so that the adequacy carried out work as a whole and in parallel with the electric and electronic devices already installed. inside the new installed devices, is provided with a control software and supervision called SCADA, which interacts with the machine through a direct communication with a programmable logical controller S7200; this device is the intermediary between the SCADA and the different variables associated with the process of molded of plastic pieces. The SCADA system recorded the temperatures of the plasticizing tube; allows you to adjust the temperature set points required; times associated with the process of plasticizing; also allows you to select the command of operation of the machine between manual and automatic, as final quality you can adjust the number of repetitions cyclical in the automatic operating mode

High Hydrostatic Pressure Processing for Improving the Control of Listeria monocytogenes on Ready-to-Eat (RTE) Sliced Ham with Variable Nitrite Concentrations

High pressure processing at 600 MPa, as used commercially, was confirmed as highly effective for control of Listeria monocytogenes on sliced ham manufactured with various nitrite concentrations and nitrite sources. Growth of L. monocytogenes was slowed but not prevented by addition of nitrite, as expected. Reducing the HPP treatment to 400 MPa with addition of nitrite, regardless of the concentration or source of the nitrite, was not as effective as 600 MPa for inhibiting L. monocytogenes, indicating that the addition of nitrite did not reduce the amount of pressure needed for effective HPP, counter to our hypothesis. These results indicate that processors of RTE meat products, especially those processed as natural or organic products with nitrite concentrations that are less than conventional nitrite-cured products, should continue to use the conventional HPP process at 600 MPa for best control of L. monocytogenes on RTE meat products