Predicting the physicochemical profile of diastereoisomeric histidine-containing dipeptides by property space analysis.

OBJECTIVES: This study aimed at measuring the lipophilicity and ionization constants of diastereoisomeric dipeptides, interpreting them in terms of conformational behavior, and developing statistical models to predict them. METHODS: A series of 20 dipeptides of general structure NH(2) -L-X-(L or D)-His-OMe was designed and synthetized. Their experimental ionization constants (pK(1) , pK(2) and pK(3) ) and lipophilicity parameters (log P(N) and log D(7.4) ) were measured by potentiometry. Molecular modeling in three media (vacuum, water, and chloroform) was used to explore and sample their conformational space, and for each stored conformer to calculate their radius of gyration, virtual log P (preferably written as log P(MLP) , meaning obtained by the molecular lipophilicity potential (MLP) method) and polar surface area (PSA). Means and ranges were calculated for these properties, as was their sensitivity (i.e., the ratio between property range and number of rotatable bonds). RESULTS: Marked differences between diastereoisomers were seen in their experimental ionization constants and lipophilicity parameters. These differences are explained by molecular flexibility, configuration-dependent differences in intramolecular interactions, and accessibility of functional groups. Multiple linear equations correlated experimental lipophilicity parameters and ionization constants with PSA range and other calculated parameters. CONCLUSION: This study documents the differences in lipophilicity and ionization constants between diastereoisomeric dipeptides. Such configuration-dependent differences are shown to depend markedly on differences in conformational behavior and to be amenable to multiple linear regression. Chirality 24:566-576, 2012. © 2012 Wiley Periodicals, Inc.

Public Art, strategies for the regeneration of public space

This paper discusses some of the key concepts in the consideration of public art as a central element in urban regeneration processes, especially in reference to its role in the processes of citizen participation.

Hospital antibiotic consumption in Switzerland: comparison of a multicultural country with Europe.

The consumption of antibiotics in the inpatient setting of Switzerland was assessed to determine possible differences between linguistic regions, and to compare these results with European results. Data on antibiotic consumption were obtained from a sentinel network representing 54% of the national acute care hospitals, and from a private drug market monitoring company. Aggregated data were converted into defined daily doses (DDD). The total consumption density in Switzerland was close to the median consumption reported in European surveys. Between 2004 and 2008, the total consumption of systemic antibiotics rose from 46.1 to 54.0 DDD per 100 occupied bed-days in the entire hospitals, and from 101.6 to 114.3 DDD per 100 occupied bed-days in the intensive care units. Regional differences were observed for total consumption and among antibiotic classes. Hospitals in the Italian-speaking region showed a significantly higher consumption density, followed by the French- and German-speaking regions. Hospitals in the Italian-speaking region also had a higher consumption of fluoroquinolones, in line with the reported differences between Italy, Germany and France. Antibiotic consumption in acute care hospitals in Switzerland is close to the European median with a relatively low consumption in intensive care units. Some of the patterns of variation in consumption levels noticed among European countries are also observed among the cultural regions of Switzerland.

Reflexiones sobre el espacio público = Thoughts on Public Space

En este artículo planteamos una aproximación a la idea de espacio público como articulador del conjunto de acontecimientos que intervienen en la vida de las ciudades. Entendemos este fenómeno como una red poliédrica y multidimensional, cuyo estudio pasa por el análisis de diversas problemáticas: la identificación de los límites entre espacio público y esfera pública; la conformación del espacio público construido; la aproximación teórica al fenómeno desde la contemporaneidad; la dimensión social del espacio público; y finalmente la perspectiva de la gestión de las ciudades. Todas estas dimensiones expresan una mirada crítica del objeto i ponen en valor niveles de trabajo interdisciplinar y multiescala, fundamentales para entender e intervenir en el espacio público de la ciudad contemporánea.

Taxing Sweets: Sweetener Input Tax or Final Consumption Tax?

In order to reduce obesity and associated costs, policymakers are considering various policies, including taxes, to change consumers high-calorie consumption habits. We investigate two tax policies aimed at reducing added sweetener consumption. Both a consumption tax on sweet goods and a sweetener input tax can reach the same policy target of reducing added sweetener consumption. Both tax instruments are regressive, but the associated surplus losses are limited. The tax on sweetener inputs targets sweeteners directly and causes about five times less surplus loss than the final consumption tax. Previous analyses have overlooked this important point.

Analysis of Markers for Recent Alcohol Consumption by Capillary Zone Electrophoresis and an Immunochemical Method

Le but de ce travail doctoral était le développement de méthodes analytiques pour la détermination dethyl glucuronide et dethyl sulfate. Ces deux substances sont des métabolites directs de lethanol qui peuvent être détectées pendant des heures jusqu'à des jours dans des fluides corporels, après que léthanol ait été complètement éliminé du corps humain. Ce sont donc des marqueurs de consommation récente d'alcool.La majorité des expériences ont été effectuées en utilisant l'électrophorèse capillaire. Il était envisagé de fournir des méthodes utilisables dans des laboratoires de routine. Des méthodes électrophorétiques ont été développées et optimisées pour la détermination dethyl sulfate dans le sérum et l'urine ainsi que pour lethyl glucuronide dans le sérum. Lethyl glucuronide urinaire a pu être déterminé par un immunoassay commerciale qui a en plus été adapté avec succès pour des échantillons de sérum. Avec toutes ces méthodes d'analyse il était possible d'observer les deux marqueurs de consommation d'alcool récente, même une consommation aussi basse qu'un verre de boissons alcooliques.Finalement, une étude englobant plus de 100 échantillons aété effectuée avec l'ambition de déterminer les valeurs de référence pour lethyl glucuronide dans le sérum et l'urine. De plus, la nécessité de normaliser les échantillons d'urine par rapport à la dilution a été investiguée. Grâce à cette étude des valeurs de cut-off et une base statistique pour l'interprétation probabiliste ont pu être proposées.

Oxygen consumption of Litopenaeus vannamei juveniles in heterotrophic medium with zero water exchange

This work aimed at determining the dissolved oxygen consumption rate of Litopenaeus vannamei juveniles maintained in a microbial biofloc raceway system at high density with no aeration. Three 4 L bottles were filled for each treatment, sealed hermetically, and placed in an enclosed greenhouse raceway system. Four shrimp (13.2±1.42 g) were assigned to two sets of the bottles, which underwent the following treatments: light conditions with no shrimp; dark conditions with no shrimp; light conditions with shrimp; and dark conditions with shrimp. Dissolved oxygen content was measured every 10 min for 30 min. A quadratic behavior was observed in dissolved oxygen concentration over time. Significant differences for oxigen consumption were observed only at 10 and 20 min between shrimp maintained in the dark and those under light conditions. At 10 min, a higher value was observed in shrimp maintained under light, and at 20 min, in the dark. Significant differences between 10 and 20 min and between 10 and 30 min were observed when oxygen consumption was analyzed over time in the presence of light. Under dark conditions there were significant differences only between 20 and 30 min. Lethal oxygen concentration (0.65 mg L-1) would be reached in less than one hour either under light or dark conditions with no aeration.

White under Black. Works from the Imperceptible / 2. Mar Arza: Readings and Consumption...

In the works of Mar Arza we perceive a sustained concern with lines of writing on surfaces. Earlyon, she altered the pages and letters of old books. More recently she has intervened in the lettersand the blank spaces on all kinds of printed paper — savings books, electricity bills, medical referrals, calendar pages, lottery tickets...

Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth

The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs) are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length) were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo) in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree), Flemingia macrophylla (a shrubby legume) or Brachiaria decumbens (a pasture grass) was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms), Porcellionides pruinosus or Circoniscus ornatus (woodlice), and Trigoniulus corallinus (millipedes) were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.

Insulin-Like growth-factor 1 myocardial expression decreases in chronic alcohol consumption

Background Chronic alcohol ingestion may cause severe biochemical and pathophysiological derangements to skeletal muscle. Unfortunately, these alcohol-induced events may also prime skeletal muscle for worsened, delayed, or possibly incomplete repair following acute injury. As alcoholics may be at increased risk for skeletal muscle injury, our goals were to identify the effects of chronic alcohol ingestion on components of skeletal muscle regeneration. To accomplish this, age- and gender-matched C57Bl/6 mice were provided normal drinking water or water that contained 20% alcohol (v/v) for 1820 wk. Subgroups of mice were injected with a 1.2% barium chloride (BaCl2) solution into the tibialis anterior (TA) muscle to initiate degeneration and regeneration processes. Body weights and voluntary wheel running distances were recorded during the course of recovery. Muscles were harvested at 2, 7 or 14 days post-injection and assessed for markers of inflammation and oxidant stress, fiber cross-sectional areas, levels of growth and fibrotic factors, and fibrosis. Results Body weights of injured, alcohol-fed mice were reduced during the first week of recovery. These mice also ran significantly shorter distances over the two weeks following injury compared to uninjured, alcoholics. Injured TA muscles from alcohol-fed mice had increased TNFα and IL6 gene levels compared to controls 2 days after injury. Total protein oxidant stress and alterations to glutathione homeostasis were also evident at 7 and 14 days after injury. Ciliary neurotrophic factor (CNTF) induction was delayed in injured muscles from alcohol-fed mice which may explain, in part, why fiber cross-sectional area failed to normalize 14 days following injury. Gene levels of TGFβ1 were induced early following injury before normalizing in muscle from alcohol-fed mice compared to controls. However, TGFβ1 protein content was consistently elevated in injured muscle regardless of diet. Fibrosis was increased in injured, muscle from alcohol-fed mice at 7 and 14 days of recovery compared to injured controls. Conclusions Chronic alcohol ingestion appears to delay the normal regenerative response following significant skeletal muscle injury. This is evidenced by reduced cross-sectional areas of regenerated fibers, increased fibrosis, and altered temporal expression of well-described growth and fibrotic factors.

Time consumption and damage to the remaining stock in mechanised and motor manual pre-commercial thinning

Abstract

Comment diminuer son risque cardiovasculaire avec l'alimentation? Rôle des graisses consommées [Nutritional advice to help reduce the cardiovascular risk. Update of the Swiss Federal Office of Public Health's recommendations on fat consumption].

The Swiss Federal Office of Public Health's (FOPH) updated its recommendations on fat consumption in 2013. The report recommends that maximum 10% of the daily caloric intake should come from saturated fatty acids, and the total fat intake should account for 20-35%. There is no limitation to dietary cholesterol consumption. Recent studies have shown that replacing consumption of saturated fatty acids by unsaturated fatty acids is more beneficial in terms of cardiovascular prevention than a low fat diet. The purpose of this article is to review the FOPH recommendations on dietary fat as well as the current evidence about their cardiovascular benefit, and to provide a translation of these scientific recommendations into clinical advice.