Organoleptic quality of Ethiopian Arabica coffee deteriorates with increasing intensity of coffee forest management.

Arabica coffee (Coffea arabica L.) grows naturally as an understory shrub in the moist evergreen montane forests of Southwest Ethiopia. In response to an increasing local human population pressure and a growing coffee demand on the world market, coffee producing forests are increasingly managed to boost coffee yield. Here we compared organoleptic coffee quality between natural coffee producing forests, large coffee agroforests, and small coffee agroforests. Accounting for variability in Arabica coffee genotype and environment, we found that blind consensus scores, given by a panel of certified Q-Grade cuppers, were negatively affected by increasing forest management intensity. Importantly, only coffee from natural coffee producing forests qualified as specialty coffee following the Specialty Coffee Association of America's standards. We suggest that the most important drivers of deteriorating coffee quality include decreased shade levels and changing micro-climate and biotic interactions. Due to the low yields of coffee in natural coffee producing forests and the lack of quality price premiums, Ethiopian smallholder farmers are inclined to optimize for coffee quantity, rather than for quality, causing a significant challenge for the conservation of Ethiopian natural coffee producing forests.

The impact of individual human immunodeficiency virus type 1 protease mutations on drug susceptibility is highly influenced by complex interactions with the background protease sequence.

The requirement for multiple mutations for protease inhibitor (PI) resistance necessitates a better understanding of the molecular basis of resistance development. The novel bioinformatics resistance determination approach presented here elaborates on genetic profiles observed in clinical human immunodeficiency virus type 1 (HIV-1) isolates. Synthetic protease sequences were cloned in a wild-type HIV-1 background to generate a large number of close variants, covering 69 mutation clusters between multi-PI-resistant viruses and their corresponding genetically closely related, but PI-susceptible, counterparts. The vast number of mutants generated facilitates a profound and broad analysis of the influence of the background on the effect of individual PI resistance-associated mutations (PI-RAMs) on PI susceptibility. Within a set of viruses, all PI-RAMs that differed between susceptible and resistant viruses were varied while maintaining the background sequence from the resistant virus. The PI darunavir was used to evaluate PI susceptibility. Single sets allowed delineation of the impact of individual mutations on PI susceptibility, as well as the influence of PI-RAMs on one another. Comparing across sets, it could be inferred how the background influenced the interaction between two mutations, in some cases even changing antagonistic relationships into synergistic ones or vice versa. The approach elaborates on patient data and demonstrates how the specific mutational background greatly influences the impact of individual mutations on PI susceptibility in clinical patterns.

Further characterization of rat dihydroceramide desaturase: tissue distribution, subcellular localization, and substrate specificity.

The introduction of the double bond in the sphingoid backbone of sphingolipids occurs at the level of dihydroceramide via an NADPH-dependent desaturase, as discovered in permeabilized rat hepatocytes. In the rat, the enzyme activity, which has now been further characterized, appeared to be mostly enriched in liver and Harderian gland. By means of subcellular fractionation of rat liver homogenates and density gradient separation of microsomal fractions, the desaturase was localized to the endoplasmic reticulum. Various detergents were inhibitory to the enzyme, and maximal activities were obtained in the presence of NADPH and when the substrate was complexed to albumin. In the presence of albumin, the chain length of the fatty acid of the truncated dihydroceramides hardly affected the activity. Finally, in view of a likely evolutionary relationship between desaturases and hydroxylases, the formation of hydroxylated intermediates was analyzed. No evidence for their presence was found under our assay conditions.

Developing a model for quality evaluation in residential care for people with intellectual disability.

The present article describes the development of a general model for the evaluation, enhancement and assurance of quality of care processes in residential facilities for children and adults with intellectual disability. The framework is based on current theories regarding quality of life and quality evaluation, on a consensus between several participants in Delphi discussion-rounds, and on a questionnaire for care providers and clients in all Flemish residential facilities. The model describes 13 quality standards and a list of indicators concerning organization and support interventions. Facilities may use this set of criteria and indicators in several ways within a continuous and dynamic system of internal quality assurance. Finally, the prospects of and conditions for the implementation of this model are discussed.

Conversion of dihydroceramide into ceramide: involvement of a desaturase.

Ceramide has been suggested to be a potent bioactive lipid involved in cell growth, differentiation and apoptosis. Its precursor, dihydroceramide, does not affect these processes. The truncated dihydroceramide analogues N-hexanoyl-[4,5-3H]-d-erythro-sphinganine and N-[1-14C]-hexanoyl-d-erythro-sphinganine were used to study the conversion of dihydroceramide into ceramide by rat hepatocytes. The formation of tritiated water after the addition of the tritiated substrate to intact and permeabilized rat hepatocytes was followed to measure enzyme activity. Desaturation was severely depressed in permeabilized hepatocytes, suggesting loss of cofactors. Of a variety of cofactors tested in the permeabilized cells, NADPH appeared to be stimulatory, pointing to the involvement of a desaturase. In agreement with this, the addition of inhibitors and redox effectors known to affect Delta9-stearoyl-CoA desaturase and Delta1-plasmanyl-ethanolamine desaturase to intact cells resulted in severe inhibition of the desaturation. When added to permeabilized cells fortified with NADPH, these compounds counteracted the NADPH stimulation. The enzyme system was further studied in broken cells. On cell fractionation, the activity was recovered in the microsomal fraction. The results indicate that the conversion of dihydroceramide into ceramide is ctalysed by a desaturase and not by a dehydrogenase or an oxidase as was generally believed.