Implementación del sistema contable e identificación de centros de costos, aplicable a la técnica de la rizipisicicultura, como una alternativa para los agricultores de la Asociación de Regantes de Atiocoyo Sur (ARAS)

A partir del año 1,996, en El Salvador se inició el Programa de Fortalecimiento a las Asociaciones de Regantes de Atiocoyo Sur, en busca de mejorar el rendimiento en su producción, a través de la implementación de una nueva técnica de rizipiscicultura, la cual consiste en la combinación del cultivo de arroz y peces. Debido a que es una nueva forma de cultivo es necesario crear y mejorar los controles existentes de la inversión en la producción de arroz y peces, que desarrollan los agricultores, a fin de reducir costos y optimizar los recursos existentes, así como también, definir los Centros de Costos de la rizipiscicultura y presentarla como una alternativa de producción para el aprovechamiento máximo de recursos. El tipo de estudio que se realizó, tuvo un enfoque hipotético deductivo, el cual es un instrumento para el desarrollo de investigaciones llamado también cuantitativo, ya que este permitió relacionar la investigación bibliográfica y de campo. Dicha indagación se llevó a cabo en la Asociación de Agricultores del Distrito de Riego de Atiocoyo Sur, dedicado al cultivo de la tilapia y arroz en El Salvador. Al tabular y analizar los datos obtenidos de las encuestas y reforzándolas con las entrevistas se determinó mediante el diagnostico que los agricultores de Atiocoyo Sur dedicados a la producción de arroz y peces no tienen definido un modelo de centros de costos que les permita identificar las erogaciones efectuadas durante el desarrollo del cultivo por el hecho de no llevar contabilidad formal, ya que desconocen en cierta medida, la adecuada asociación contable que debe hacerse con respecto a las actividades realizadas durante las fases del cultivo. Además el producción de arroz y peces se desarrolla de manera separada utilizando para esto gran cantidad de recursos, generando elevación de costos. Por lo anterior, como aporte social del grupo se elaboró una propuesta que coopere a desarrollar un sistema contable y un modelo de centros de costos aplicados al cultivo combinado de arroz y peces que ayude a mejorar los controles de la inversión.

Asociación entre factores socioeconómicos y hábitos de limpieza en gestantes de Usaquén y Kennedy de la ciudad de Bogotá

Introducción: Actualmente existe un reconocimiento creciente de que el hogar desempeña un papel importante en varias cuestiones de higiene y salud pública. El ambiente del hogar ha sido implicado como una fuente importante de propagación de enfermedades infecciosas, y la intervención de las medidas de higiene, implican una reducción de la incidencia, especialmente en los países menos desarrollados y en poblaciones vulnerables como las gestantes. Objetivo: Evaluar la asociación entre la práctica de hábitos higiénicos de las gestantes estrato 1 y 2 de las localidades de Usaquén y Kennedy en relación a sus factores socioeconómicos. Métodos: Estudio Analítico de Corte transversal. Se realizó en las gestantes de los estratos 1 y 2 de las localidades de Usaquén y Kennedy en la ciudad de Bogotá. Se recolectaron datos referentes a factores socioeconómicos y hábitos de higiene de 141 gestantes a través de la aplicación de una encuesta. Los datos obtenidos de las variables de interés fueron procesados a través de análisis multivariado y regresión logística paramétrica y no paramétrica, con el fin de establecer si existía asociación o no entre las mismas. Resultados: Existe asociación entre el número de Nacidos vivos y la presencia de plagas (p=0.034 y Coeficiente de correlación: -1.253). Así mismo se encontró asociación habitar en cuartos rentados y la limpieza de casa general (p=0.008 y Coeficiente de correlación: 0.480). Existe una asociación entre la variable edad y el lavado de frutas (p=0.041 y Coeficiente de correlación: 0.384). Conclusiones: Existe relación entre los hábitos higiénicos y los factores socioeconómicos de las gestantes estudiadas. Existe un mayor hábito de lavado de frutas antes de ser consumidas en gestantes de mayor edad. Adicional a esto se evidencia a mayor número de hijos hay menor presencia de plagas en el hogar y mayor limpieza del hogar. Solo en un pequeño porcentaje de los hogares se evidencio una óptima limpieza, por lo cual se deben plantear más políticas para mejorar la higiene de los mismos ya que los datos reportados permanecen subóptimos en la población seleccionada.

Análisis de experiencias de resistencia no violenta en el departamento del Caquetá: los casos de la asociación RED UNIOS y la asociación por la vida del agua

El presente artículo académico busca analizar las prácticas culturales y métodos de resistencia noviolenta utilizados por las Comisiones por la Vida del Agua (CVA) de Valparaíso y la Asociación RED UNÍOS de San Vicente del Caguán, para preservar el territorio ante las políticas petroleras presentes en el Departamento del Caquetá, entre los años 2010 y 2016. A lo largo de la investigación se pretende dar cuenta de cómo dichas acciones, relacionadas en la tipificación de Gene Sharp como resistencias noviolentas, han construido una conciencia de preservación en algunas comunidades del departamento a través de los ejercicios de protesta, persuasión, intervención y no-cooperación. Para lograr dicho objetivo, se realizó un análisis de documentos de la prensa oficial del departamento del Caquetá, de las redes sociales de las dos organizaciones mencionadas y un trabajo de campo basado en entrevistas semiestructuradas a los colaboradores de las mismas.

The stimulation of healing within a rat calvarial defect by mPCL–TCP/collagen scaffolds loaded with rhBMP-2

Bone morphogenetic proteins (BMPs) have been widely investigated for their clinical use in bone repair and it is known that a suitable carrier matrix to deliver them is essential for optimal bone regeneration within a specific defect site. Fused deposited modeling (FDM) allows for the fabrication of medical grade poly 3-caprolactone/tricalcium phosphate (mPCL–TCP) scaffolds with high reproducibility and tailor designed dimensions. Here we loaded FDM fabricated mPCL–TCP/collagen scaffolds with 5 mg recombinant human (rh)BMP-2 and evaluated bone healing within a rat calvarial critical-sized defect. Using a comprehensive approach, this study assessed the newly regenerated bone employing microcomputed tomography (mCT), histology/histomorphometry, and mechanical assessments. By 15 weeks, mPCL–TCP/collagen/rhBMP-2 defects exhibited complete healing of the calvarium whereas the non- BMP-2-loaded scaffolds showed significant less bone ingrowth, as confirmed by mCT. Histomorphometry revealed significantly increased bone healing amongst the rhBMP-2 groups compared to non-treated scaffolds at 4 and 15 weeks, although the % BV/TV did not indicate complete mineralisation of the entire defect site. Hence, our study confirms that it is important to combine microCt and histomorphometry to be able to study bone regeneration comprehensively in 3D. A significant up-regulation of the osteogenic proteins, type I collagen and osteocalcin, was evident at both time points in rhBMP-2 groups. Although mineral apposition rates at 15 weeks were statistically equivalent amongst treatment groups, microcompression and push-out strengths indicated superior bone quality at 15 weeks for defects treated with mPCL–TCP/collagen/rhBMP-2. Consistently over all modalities, the progression of healing was from empty defect < mPCL–TCP/collagen < mPCL–TCP/collagen/rhBMP-2, providing substantiating data to support the hypothesis that the release of rhBMP-2 from FDM-created mPCL–TCP/collagen scaffolds is a clinically relevant approach to repair and regenerate critically-sized craniofacial bone defects. Crown Copyright 2008 Published by Elsevier Ltd. All rights reserved.

The foraging behaviour of the Black rat (Rattus rattus) within Australian macadamia orchards

The black rat (Rattus rattus) has been shown to be the primary species responsible for causing significant crop losses within the Australian macadamia industry. This species success within macadamia orchards is directly related to the flexibility expressed in its foraging behaviour. In this paper a conceptual foraging model is presented which proposes that the utilisation of resources by rodents within various components of the system is related not only to their relative abundance, but also to predator avoidance behaviour. Nut removal from high predation risk habitats during periods of low resource abundance in low risk compartments of the system is considered an essential behaviour that allows high rodent densities to be maintained throughout the year.

P2 purinergic receptor mRNA in rat and human sinoatrial node and other heart regions.

It is known that adenosine 5'-triphosphate (ATP) is a cotransmitter in the heart. Additionally, ATP is released from ischemic and hypoxic myocytes. Therefore, cardiac-derived sources of ATP have the potential to modify cardiac function. ATP activates P2X(1-7) and P2Y(1-14) receptors; however, the presence of P2X and P2Y receptor subtypes in strategic cardiac locations such as the sinoatrial node has not been determined. An understanding of P2X and P2Y receptor localization would facilitate investigation of purine receptor function in the heart. Therefore, we used quantitative PCR and in situ hybridization to measure the expression of mRNA of all known purine receptors in rat left ventricle, right atrium and sinoatrial node (SAN), and human right atrium and SAN. Expression of mRNA for all the cloned P2 receptors was observed in the ventricles, atria, and SAN of the rat. However, their abundance varied in different regions of the heart. P2X(5) was the most abundant of the P2X receptors in all three regions of the rat heart. In rat left ventricle, P2Y(1), P2Y(2), and P2Y(14) mRNA levels were highest for P2Y receptors, while in right atrium and SAN, P2Y(2) and P2Y(14) levels were highest, respectively. We extended these studies to investigate P2X(4) receptor mRNA in heart from rats with coronary artery ligation-induced heart failure. P2X(4) receptor mRNA was upregulated by 93% in SAN (P < 0.05), while a trend towards an increase was also observed in the right atrium and left ventricle (not significant). Thus, P2X(4)-mediated effects might be modulated in heart failure. mRNA for P2X(4-7) and P2Y(1,2,4,6,12-14), but not P2X(2,3) and P2Y(11), was detected in human right atrium and SAN. In addition, mRNA for P2X(1) was detected in human SAN but not human right atrium. In human right atrium and SAN, P2X(4) and P2X(7) mRNA was the highest for P2X receptors. P2Y(1) and P2Y(2) mRNA were the most abundant for P2Y receptors in the right atrium, while P2Y(1), P2Y(2), and P2Y(14) were the most abundant P2Y receptor subtypes in human SAN. This study shows a widespread distribution of P2 receptor mRNA in rat heart tissues but a more restricted presence and distribution of P2 receptor mRNA in human atrium and SAN. This study provides further direction for the elucidation of P2 receptor modulation of heart rate and contractility.

Heparan sulfate mediates the proliferation and differentiation of rat mesenchymal stem cells

The growth and differentiation of mesenchymal stem cells is controlled by various growth factors, the activities of which can be modulated by heparan sulfates. We have previously underscored the necessity of sulfated glycosaminoglycans for the FGF-2-stimulated differentiation of osteoprogenitor cells. Here we show that exogenous application of heparan sulfate to cultures of primary rat MSCs stimulates their proliferation leading to increased expression of osteogenic markers and enhanced bone nodule formation. FGF-2 can also increase the proliferation and osteogenic differentiation of rMSCs when applied exogenously during their linear growth. However, as opposed to exogenous HS, the continuous use of FGF-2 during in vitro differentiation completely blocked rMSC mineralization. Furthermore, we show that the effects of both FGF-2 and HS are mediated through FGF receptor 1 (FGFR1) and that inhibition of signaling through this receptor arrests cell growth resulting in the cells being unable to reach the critical density necessary to induce differentiation. Interestingly, blocking FGFR1 signaling in post-confluent osteogenic cultures significantly increased calcium deposition. Taken together our data clearly suggests that FGFR1 signaling plays an important role during osteogenic differentiation, firstly by stimulating cell growth that is closely followed by an inhibitory affect once the cells have reached confluence. It also underlines the importance of HS as a co-receptor for the signaling of endogenous FGF-2 and suggests that purified glycosaminoglycans may be attractive alternatives to growth factors for improved ex vivo growth and differentiation of MSCs.

Sustained release and osteogenic potential of heparan sulfate-doped fibrin glue scaffolds within a rat cranial model

This paper explores the potential therapeutic role of the naturally occurring sugar heparan sulfate (HS) for the augmentation of bone repair. Scaffolds comprising fibrin glue loaded with 5 lg of embryonically derived HS were assessed, firstly as a release-reservoir, and secondly as a scaffold to stimulate bone regeneration in a critical size rat cranial defect. We show HS-loaded scaffolds have a uniform distribution of HS, which was readily released with a typical burst phase, quickly followed by a prolonged delivery lasting several days. Importantly, the released HS contributed to improved wound healing over a 3-month period as determined by microcomputed tomography (lCT) scanning, histology, histomorphometry, and PCR for osteogenic markers. In all cases, only minimal healing was observed after 1 and 3 months in the absence of HS. In contrast, marked healing was observed by 3 months following HS treatment, with nearly full closure of the defect site. PCR analysis showed significant increases in the gene expression of the osteogenic markers Runx2, alkaline phosphatase, and osteopontin in the heparin sulfate group compared with controls. These results further emphasize the important role HS plays in augmenting wound healing, and its successful delivery in a hydrogel provides a novel alternative to autologous bone graft and growth factorbased therapies.

RatSLAM on the edge : revealing a coherent representation from an overloaded rat brain

The RatSLAM system can perform vision based SLAM using a computational model of the rodent hippocampus. When the number of pose cells used to represent space in RatSLAM is reduced, artifacts are introduced that hinder its use for goal directed navigation. This paper describes a new component for the RatSLAM system called an experience map, which provides a coherent representation for goal directed navigation. Results are presented for two sets of real world experiments, including comparison with the original goal memory system's performance in the same environment. Preliminary results are also presented demonstrating the ability of the experience map to adapt to simple short term changes in the environment.

Investigating the effects of preinduction on human adipose-derived precursor cells in an athymic rat model

The osteogenic potential of human adipose-derived precursor cells seeded on medical-grade polycaprolactone-tricalcium phosphate scaffolds was investigated in this in vivo study. Three study groups were investigated: (1) induced—stimulated with osteogenic factors only after seeding into scaffold; (2) preinduced—induced for 2 weeks before seeding into scaffolds; and (3) uninduced—cells without any introduced induction. For all groups, scaffolds were implanted subcutaneously into the dorsum of athymic rats. The scaffold/cell constructs were harvested at the end of 6 or 12 weeks and analyzed for osteogenesis. Gross morphological examination using scanning electron microscopy indicated good integration of host tissue with scaffold/cell constructs and extensive tissue infiltration into the scaffold interior. Alizarin Red histology and immunostaining showed a heightened level of mineralization and an increase in osteonectin, osteopontin, and collagen type I protein expression in both the induced and preinduced groups compared with the uninduced groups. However, no significant differences were observed in these indicators when compared between the induced and preinduced groups.