Animals : multicelled life.

Este título pertenece a una serie que ofrece en profundidad una visión de las células en todos los seres vivientes, su estructura y los procesos en que se basa la vida en la Tierra. Todos los animales, incluidos los seres humanos, están formados por millones de células. Aquí se ven las diferencias entre las células de una planta y las células de un animal. Se muestra como las células de un animal se adaptan a su actividad, estilo de vida móvil, y explora cómo estas células se especializan para realizar diferentes tareas, desde la lucha contra la infección hasta el transporte de nutrientes. Tiene índice, glosario, referencias bibliográficas y un cuadro de clasificación del reino animal.

From DNA to GM wheat : discovering genetic modification of food.

Para que los estudiantes desarrollen habilidades en la lectura de textos de no ficción. En esta colección se exponen los avances, inventos y descubrimientos de la ciencia , y cómo un descubrimiento o la invención de una persona puede dar lugar a una serie de descubrimientos hechos por los demás, e incluso una cadena de descubrimientos científicos. Este título proporciona una visión general del ADN. Se describe cómo se descubrió, la investigación realizada sobre los genes, por qué las plantas y los animales son genéticamente modificados, y los pros y los contras de usar esta forma de la biotecnología. Tiene relación cronológica de descubrimientos, unas breves biografías de los científicos clave en sus respectivos campos, glosario y bibliografía.

Sobre les utopies, els animals i les figures del ciutad??

Resumen basado en el de la publicaci??n

Production risk, pesticide use and GM crop technology in South Africa

Technology involving genetic modification of crops has the potential to make a contribution to rural poverty reduction in many developing countries. Thus far, pesticide-producing Bacillus thuringensis (Bt) varieties of cotton have been the main GM crops under cultivation in developing nations. Several studies have evaluated the farm-level performance of Bt varieties in comparison to conventional ones by estimating production technology, and have mostly found Bt technology to be very successful in raising output and/or reducing pesticide input. However, the production risk properties of this technology have not been studied, although they are likely to be important to risk-averse smallholders. This study investigates the output risk aspects of Bt technology by estimating two 'flexible risk' production function models allowing technology to independently affect the mean and higher moments of output. The first is the popular Just-Pope model and the second is a more general 'damage control' flexible risk model. The models are applied to cross-sectional data on South African smallholders, some of whom used Bt varieties. The results show no evidence that a 'risk-reduction' claim can be made for Bt technology. Indeed, there is some evidence to support the notion that the technology increases output risk, implying that simple (expected) profit computations used in past evaluations may overstate true benefits.

Tolerance of ruminant animals to high dose in-feed administration of a selenium-enriched yeast

The objective of the study was to determine if there were adverse effects on animal health and performance when a range of ruminant animals species were fed at least 10 times the maximum permitted European Union (EU) selenium (Se) dietary inclusion rate (0.568 mg Se/kg DM) in the form of selenium enriched yeast (SY) derived from a specific strain of Saccharomyces cerevisiae CNCM I-3060. In a series of studies, dairy cows, beef cattle, calves and lambs were offered either a control diet which contained no Se supplement or a treatment diet which contained the same basal feed ingredients plus a SY supplement which increased total dietary Se from 0.15 to 6.25, 0.20 to 6.74, 0.15 to 5.86 and 0.14 to 6.63 mg Se/kg DM, respectively. The inclusion of the SY supplement (P < 0.001) increased whole blood Se concentrations, reaching maximum mean values of 716, 1,505, 1,377, and 724 ng Se/mL for dairy cattle, beef cattle, calves and lambs, respectively. Selenomethionine accounted for 10% of total whole blood Se in control animals whereas the proportion in SY animals ranged between 40 and 75%. Glutathione peroxidase (EC 1.11.1.9) activity was higher (P < 0.05) in SY animals when compared with controls. A range of other biochemical and hematological parameters were assessed, but few differences of biological significance were established between treatments groups. There were no differences between treatment groups within each species with regard to animal physical performance or overall animal health. It was concluded that there were no adverse effects on animal health, performance and voluntary feed intake to the administration of at least ten times the EU maximum, or approximately twenty times the US FDA permitted concentration of dietary Se in the form of SY derived from a specific strain of Saccharomyces cerevisiae CNCM I-3060.