We analyze in juvenile Cherax quadricarinatus fattening stage, the circadian rhythm of total protein levels, activity of proteases, lipases and amylases, and their possible change as a function of morning (8 h) and evening (17 h) feeding. In general, the activity of digestive enzymes of juvenile C. quadricarinatus showed no circadian pattern of secretion of lipases except where there was an increase towards the evening-night and a decrease towards the early hours of the morning. The total protein levels, the activity of proteinases and amylases of juveniles of C. quadricarinatus registered in the midgut gland remained virtually unchanged in all experiments. However, a non-significant tendency to diminish the proteinase activity levels after the feeding pulse was observed, with a return to previous enzymatic levels after 3 h. In contrast, the amylase activity did not show an observable effect by the feeding schedule. The study of the patterns of the digestive enzyme secretion and their possible changes, could be used as a tool to establish the most favorable times of the day for juveniles feeding. | Se analiza en juveniles en etapa de engorde (7 g) de Cherax quadricarinatus, el ritmo circadiano de los niveles de proteínas totales, la actividad de las proteasas, lipasas y amilasas, y su posible modificación en función del momento de alimentación matutino (8 h) y vespertino (17 h). En general, la actividad de las enzimas digestivas de los juveniles de C. quadricarinatus no mostró un patrón circadiano de secreción, a excepción de las lipasas, donde se observó un incremento de actividad hacia la tarde-noche y disminución hacia las primeras horas de la mañana. Los niveles de proteína total, la actividad de proteinasas y amilasas registradas en la glándula digestiva, permanecieron prácticamente inalterados en todos los experimentos. A pesar de ello, se observó tendencia a que los niveles de actividad de proteinasas disminuyan luego del pulso de alimentación, recuperando los niveles anteriores 3 h después, independientemente del horario de alimentación. En cambio la actividad de amilasa no mostró ninguna tendencia por efecto del horario de alimentación. El estudio de los patrones de secreción de las enzimas digestivas y sus posibles modificaciones, podría ser utilizado como una herramienta para establecer los momentos del día más propicios para la alimentación de los juveniles en cultivo.

The young larvae of insects living on dry food produce large amounts of water by the metabolic combustion of dietary lipids. The metabolic production of water needed for larval growth, previously known as hypermetabolic responses to juvenile hormone (JH), is associated with a 10 to 20-fold increase in the rate of O2 consumption (10,000 microL O2/g/h in contrast to the usual rate of 500 microL O2/g/h). Growing and moulting larvae are naturally hypermetabolic due to the endogenous release of JH from the corpora allata. At the last, larval-pupal or larval-adult moult there is no JH and as a consequence the metabolic rate is much lower and the dietary lipid is not metabolized to produce water but stored in the fat body. At this developmental stage, however, a hypermetabolic response can be induced by the exogenous treatment of the last larval instars with a synthetic JH analogue. In D. vulpinus, the JH-treated hypermetabolic larvae survive for several weeks without moulting or pupating. In T. castaneum and G. mellonella, the JH-treated hypermetabolic larvae moult several times but do not pupate. All these larvae consume dry food and the hypermetabolic response to JH is considered to be a secondary feature of a hormone, which is produced by some subordinated endocrine organ. The organ is most probably the controversial prothoracic gland (PG), which is a typical larval endocrine gland that only functions when JH is present. According to our hypothesis, PG activated by JH releases an adipokinetic superhormone, which initiates the conversion of dietary lipid into metabolic water. This type of metabolic combustion of dietary lipid produces large quantities of endothermic energy, which is dissipated by the larvae in the form of heat. Thermovision imaging revealed that the body of hypermetabolic larvae of G. mellonella can be as hot as 43 deg C or more. In contrast, the temperature of "cold" normal last instar larvae did not differ significantly from that of their environment. It is highly likely that thermovision will facilitate the elucidation of the currently poorly understood hormonal mechanisms that initiate the production of metabolic water essential for the survival of insects that live in absolutely dry conditions.

The young larvae of insects living on dry food produce large amounts of water by the metabolic combustion of dietary lipids. The metabolic production of water needed for larval growth, previously known as hypermetabolic responses to juvenile hormone (JH), is associated with a 10- to 20-fold increase in the rate of O2 consumption (10,000 µl O2/g/h in contrast to the usual rate of 500 µl O2/g/h). Growing and moulting larvae are naturally hypermetabolic due to the endogenous release of JH from the corpora allata. At the last, larval-pupal or larval-adult moult there is no JH and as a consequence the metabolic rate is much lower and the dietary lipid is not metabolized to produce water but stored in the fat body. At this developmental stage, however, a hypermetabolic response can be induced by the exogenous treatment of the last larval instars with a synthetic JH analogue. In D. vulpinus, the JH-treated hypermetabolic larvae survive for several weeks without moulting or pupating. In T. castaneum and G. mellonella, the JH-treated hypermetabolic larvae moult several times but do not pupate. All these larvae consume dry food and the hypermetabolic response to JH is considered to be a secondary feature of a hormone, which is produced by some subordinated endocrine organ. The organ is most probably the controversial prothoracic gland (PG), which is a typical larval endocrine gland that only functions when JH is present. According to our hypothesis, PG activated by JH (not by a hypothetical PTTH) releases an adipokinetic superhormone, which initiates the conversion of dietary lipid into metabolic water. This type of metabolic combustion of dietary lipid produces large quantities of endothermic energy, which is dissipated by the larvae in the form of heat. Thermovision imaging revealed that the body of hypermetabolic larvae of G. mellonella can be as hot as 43°C or more. In contrast, the temperature of "cold" normal last instar larvae did not differ significantly from that of their environment. It is highly likely that thermovision will facilitate the elucidation of the currently poorly understood hormonal mechanisms that initiate the production of metabolic water essential for the survival of insects that live in absolutely dry conditions.

"La investigación se realizó en un establo lechero ubicado en la carretera Gómez Palacio-Tlahualilo de la Comarca Lagunera. Se utilizaron 16 vacas que se distribuyeron en 2 grupos; el grupo #1 al cual se le proporciono agua tratada con dióxido de cloro e hipoclorito de sodio en una concentración de 10 ppm ad libitum y el grupo #2 al cual se le proporciono agua sin tratamiento directo del pozo del establo. El objetivo de este estudio fue investigar el efecto de un agua tratada y mejorada en sus características organolépticas, físicas y bacteriológicas en el comportamiento y actividades fisiológicas del ganado bovino lechero. El agua es un elemento importante primeramente para la vida ya que es un componente de mayor presencia en el organismo y en cada una de las funciones fisiológicas juega un papel importante desde un solvente hasta un amortiguador de temperatura y siendo el resultado también de diversos procesos metabólicos, constituyendo el 55 a 60% del peso corporal de una vaca, además constituye el 87% de la leche que es un producto importante hablando de bovinos lecheros. Además que es un elemento que permite mantener el estado de confort del ganado en ambientes cálidos y húmedos que es influyente para la producción láctea. El siguiente trabajo fue realizado en relación del agua tratada dentro de una explotación y agua sin tratamiento que es administrada al resto de los animales. X En esta investigación de acuerdo a los resultados obtenidos, el consumo de agua tratada con hipoclorito de sodio y dióxido de cloro por vacas Holstein lactantes aumenta significativamente la producción de leche y que cuando el bovino lactante consume agua tratada con hipoclorito de sodio y dióxido de cloro, estimula significativamente la frecuencia y el tiempo de tomas de agua para sus procesos fisiológicos que puede tener un efecto positivo sobre la producción y una tendencia de aumentar el consumo de alimento"

M. Agric. University of KwaZulu-Natal, Pietermaritzburg 2013. | Agriculture plays an important role in rural livelihoods. However, poverty and food insecurity still persist in rural communities of South Africa where women are central to ensuring household food security through several livelihood activities including agriculture. Women engage in land-based livelihood such as irrigated agriculture to increase household food security and reduce reliance on cash to feed their households. However, poor access to water and insecure access to productive resources such as land threatens rural livelihoods and are a major constraint to poverty reduction in rural areas. According to IFPRI (2012)’s Women Empowerment in Agriculture Index (WEAI), access to production resources is an important domain for empowerment of women farmers. The aim of the study was to investigate dynamics under which rural women operate when accessing water to improve the land-based livelihoods that they engage in for improving livelihoods and household food security and to investigate the knowledge rural women possess or lack in empowering themselves for improved land-based livelihoods and improving household food security. Three small scale irrigation schemes from three district municipalities in Limpopo province, South Africa, were investigated using mixed methods approach, involving quantitative and qualitative approaches, was employed. Sampling of the participants in each irrigation scheme was done through purposive sampling. Structured questionnaires, administered to women farmers through face-to-face interviews, key informant interviews, focus group discussions and observations were used for data triangulation. The study revealed that women faced various challenges when accessing water which ranged from distant sources, unreliable and inadequate supply of water and poor irrigation infrastructure to insecure land rights. Women engaged in irrigated agriculture and livestock farming. They possessed adequate knowledge on soil preparation, weeding and harvesting. However, lack of knowledge on water management and conservation, pest management and markets was observed as an impediment to women empowerment. Ensuring secure access to adequate land and water to rural women and providing skills and knowledge for agriculture and production while ensuring access to markets may contribute to empowerment of rural women and improved land-based livelihoods that rural women engage in to improve household food security which leads to poverty reduction.

A new, simple, and rapid separation and preconcentration procedure, for determination of Pb(II), Cd(II), Zn(II), and Co(II) ions in environmental real samples, has been developed. The method is based on the combination of coprecipitation of analyte ions by the aid of the Mo(VI)–diethyldithiocarbamate–(Mo(VI)-DDTC) precipitate and flame atomic absorption spectrometric determinations. The effects of experimental conditions like pH of the aqueous solution, amounts of DDTC and Mo(VI), standing time, centrifugation rate and time, sample volume, etc. and also the influences of some foreign ions were investigated in detail on the quantitative recoveries of the analyte ions. The preconcentration factors were found to be 150 for Pb(II), Zn(II) and Co(II), and 200 for Cd(II) ions. The detection limits were in the range of 0.1–2.2 μg L⁻¹ while the relative standard deviations were found to be lower than 5 % for the studied analyte ions. The accuracy of the method was checked by spiked/recovery tests and the analysis of certified reference material (CRM TMDW-500 Drinking Water). The procedure was successfully applied to seawater and stream water as liquid samples and baby food and dried eggplant as solid samples in order to determine the levels of Pb(II), Cd(II), Zn(II), and Co(II) ions.