Search Results - (Author, Cooperation:G. Escobar)

2014-05-30

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Antigens, CD34/metabolism ; DNA, Complementary/genetics ; Endonucleases/metabolism ; Fetal Blood/cytology/metabolism/transplantation ; Gene Targeting/*methods ; Genome, Human/*genetics ; Hematopoiesis/genetics ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells/*cytology/*metabolism ; Humans ; Interleukin Receptor Common gamma Subunit/genetics ; Male ; Mice ; Mutation/genetics ; Targeted Gene Repair/*methods ; X-Linked Combined Immunodeficiency Diseases/*genetics/therapy

1475-2743

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract. This article explores the question of how scientific information can improve local agronomic management using concepts of uncertainty classification and uncertainty management. Information and data on local management of soil fertility based on a local classification system of soil quality were collected from a small watershed in Cauca (Colombia). The analyses suggest that farmers hold local knowledge about soils at two levels. The first is based on empirical observations and refers to local knowledge about soils and landscape, which shows that the classes identified in the local soil quality classification are consistent with results obtained using measured soil parameters. At the second level, farmers have some awareness of ecological processes and the appropriate use of relationships between key soil characteristics and management options. It is argued that local knowledge is not sufficient to cope with uncertainty introduced by a rapidly changing agriculture, including, for example, increasing land pressure, unpredictable market forces and climate change. We have suggested how scientific knowledge can contribute to the solution, based on an analysis that relates Cohen's (Heuristic reasoning about uncertainty: an artificial intelligence approach. Pitman London, 1985) and Rowe's (Risk Analysis 14, 743–750, 1994) uncertainty concepts to local knowledge.

Electronic Resource

1365-2621

Blackwell Publishing Journal Backfiles 1879-2005

Process Engineering, Biotechnology, Nutrition Technology

A three-parameter kinetic equation was developed for ethanol extraction of oleoresin from dry red peppers under different solute to solvent ratios, particle sizes and condition of structural damage. The model distinguished two main mechanisms of extraction: a fast, washing step and a diffusion-controlled process. Flaking and, to a lesser extent, blanching induced significant cellular damage resulting in more oleoresin being washed, a faster extraction rate and a higher final concentration in the solvent, compared to untreated material. The activation energy for extraction derived from the study was 6.1 kcal/mol, typical of diffusion-controlled processes. Light micrographs related microstructure to variations in extraction parameters.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] THE idea that induction of goitrogenesis by propylthiouracil (PTU) and related compounds only involves those effects of such drugs which lead to the blocking of thyroid hormone synthesis is generally accepted. The hypothesis that these goitrogens do not have an extrathyroidal effect on thyroxine ...

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1432-1106

Adult hypothyroidism ; Dendritic spines ; Pyramidal cells ; Cerebral cortex ; Rat

Springer Online Journal Archives 1860-2000

Medicine

Summary We have previously shown (Ruiz-Marcos et al. 1980, 1982) that thyroidectomy (T) performed in rats at 40 days of age, well past the neonatal period of development, results by 80–90 days of age in a decrease of the number of spines along the shaft of pyramidal neurons with the cell body in layer V in the visual area of the cerebral cortex. We have here studied how soon after the operation an effect on spine number and distribution may be observed. We have found that the response of these neurons to T is very rapid: a decrease in the number of spines/shaft between T and age-paired controls (C) rats is statistically significant by the earliest period of observation, namely 5 days after T. These results may be related to those of Dembri et al. (1983) showing that T performed in adult rats decreases the activity of Type I RNA polymerase by 5 days after the operation. It is possible that T impairs the synthesis of some compound(s) necessary for the formation and maintenance of spines. The present results suggest that spine number is not a fixed structure of the apical shaft once brain development is over, but is in a state of continuous formation and degradation. We have further observed that the effect of T performed at 40 days of age is more pronounced in the distal part of the shaft than on the rest, a result similar to that found after neonatal T (Ruiz-Marcos et al. 1982). However, contrary to findings after early hypothyroidism, T at 40 days of age does not distort the distribution of spines along the shaft.

Electronic Resource