SYNTHESIS OF AROMA COMPONENTS DURING THE SPONTANEOUS FERMENTATION OF LAMBIC AND GUEUZE

Lambic is a type of Belgian beer obtained by spontaneous fermentation of wort. The fermentation in casks takes almost two years, and after that period the beer may be re-fermented in bottles and is then called gueuze. To gain insight into the many microbiological transformations occurring during this process, a qualitative and quantitative study of several components formed over a two-year period was undertaken. It was found that lambic and gueuze are characterized by high contents of ethyl acetate, ethyl lactate, lactic acid and acetic acid. Two phases of fermentation may be distinguished: a primary phase lasting for about three months during which almost all the ethanol and higher alcohols are formed and a very long secondary phase during which lactic acid is formed first, followed by ethyl lactate. Some lower fatty acids, including all the acetic acid, are made at the very beginning of the first phase. An important part of the ethyl acetate is made during the first phase but the amounts increase slowly to high levels during the second phase. Unusually low amounts of isoamyl acetate are detected. Several components are above the reported threshold levels of taste and are thus probably involved in the genesis of the typical aroma of lambic and gueuze. These results will allow a further study of the relations between the components found and the microbial populations involved in the spontaneous fermentation inherent in the brewing of lambic and gueuze.     

Residential Dynamics in Ethnic Concentrations

In many countries and cities there is fear that large residential concentrations of ethnic minorities will hinder integration and give rise to sub-societies that may eventually come to have little to do with each other. However, while governments develop policies aimed at spatial mixing of various population categories, the actual knowledge about ethnic concentrations and their development is rather thin. This paper intends to contribute to filling this gap in knowledge about ethnic concentrations and related dynamics using very detailed spatial data on settlement patterns in the city of Amsterdam. It focuses on residential concentrations of Moroccans and Turks and analysed the changes with regard to these concentrations between 1994 and 2004. In general no indications were found that one of these groups is consciously strengthening the ethnic identity of the residential areas they live in. Although the existing Moroccan clusters did appear to have become somewhat more Moroccan, the Moroccans themselves experienced a negative migration balance in those areas. Turkish clusters became even less Turkish and there was also a negative migration balance among Turks. Furthermore, concentrations within the 1994 boundaries were, in 2004, less Moroccan and Turkish than would be expected, given the developments that took place in Amsterdam as a whole. Detailed analysis of the clusters demonstrated no clear systematic increase or expansion of existing clusters. Analyses of associations with housing supply support the assertion that the residential dynamics of immigrants must be seen primarily as resulting from a number of steps in the residential career. Residential behaviour that has been described for the immigrant categories in question can be assumed to reflect a development toward integration.     

新能源分比例渗透下基于博弈的多主体效益综合评估方法

“双碳”目标下新能源大规模发展,新能源的发展给各能源主体带来了影响,如何量化评估新能源渗透给能源主体带来的影响成为研究重点。首先,基于改进的K-means算法构建基于典型场景集的新能源出力模型;然后,从源-网-荷-储出发,构建火力发电商、电网、用户、储能运营商的决策优化模型;其次,构建考虑新能源渗透的多能源主体效益评估模型;最后,进行算例分析,算例结果验证了模型的有效性。     

GREEN UMBU (SPONDIAS TUBEROSA ARR. CAM.) PRESERVE: PHYSICAL, CHEMICAL AND MICROBIOLOGICAL CHANGES DURING STORAGE

A preserve made from “umbu” in the green state of maturity represents an alternative to avoid losses of the fruit in the mature stage. A factorial experimental design was used to evaluate the effects of formulation, packaging and storage time (0, 45 and 90 days) on the physicochemical, chemical, physical and microbiological characteristics of the preserve during storage under ambient conditions (33C/88% relative humidity). The results showed that the products were microbiologically stable, but that degradation of soluble pectin, reducing sugars and total soluble solids occurred, especially in the cellophane packaging, and this resulted in textural and color changes in the products. The results suggested the incorporation of pectin and glucose syrup and the use of a polypropylene packaging as being the most adequate method of producing and conserving preserves made from this pulp.     

The myelotoxicity of chloramphenicol: in vitro and in vivo studies: I. In vitro effects on cells in culture

1 Chloramphenicol is used extensively in non-industrialized countries for the treatment of life-threatening infections because it is cheap and effective, despite its known hemotoxicity and linkage to fatal aplastic anaemia. It is important to define the mechanism of toxicity so that means can be devised to ameliorate the toxic effects in order to produce safer usage. 2 Chloramphenicol, at concentrations from 5 mM to 2 mM initiated apoptosis in dividing cells from a monkey kidney-derived cell line and in haematopoietic progenitor cells from human neonatal cord blood. 3 Growth of progenitor cells was suppressed at concentrations of chloramphenicol which would be considered less than therapeutic during patient treatment. 4 These effects could be ameliorated in progenitor cells by co-culture with the antioxidant mercaptoethylamine and in monkey kidney cells by co-culture with vitamin C. 5 This is the first report of apoptosis in chloramphenicol toxicity and suggests a possible link between a metabolic event i.e. the production of free radicals; a morphological effect, apoptosis; and a clinical effect, bone marrow suppression and aplastic anaemia.     

Antibiotic optimization. An evaluation of patient safety and economic outcomes

BACKGROUND: Although numerous reports have described interventions designed to influence antibiotic utilization, to our knowledge none have been evaluated in a randomized study. METHODS: Adult inpatients receiving 1 or more of 10 designated parenteral antibiotics for 3 or more days during a 3-month period were randomized to an intervention (n = 141) and a control (n = 111) group using an unblocked, computer-generated random number table. Obstetric patients and those seen in infectious disease consultation were excluded. The intervention group received antibiotic-related suggestions from a team consisting of an infectious disease fellow and a clinical pharmacist. Both groups were evaluated for clinical and microbiological outcomes as well as antibiotic utilization via prospective chart reviews and analysis of the hospital's administrative database. RESULTS: Sixty-two (49%) of the intervention group patients received a total of 74 suggestions. Sixty-three (84%) of these suggestions were implemented; the majority involved changes in antibiotic choice, dosing regimen, or route of administration. Per patient antibiotic charges were nearly $400 less in the intervention group vs controls (P = .05). Almost all the savings were related to lower intravenous antibiotic charges. Clinical and microbiological response, antibiotic-associated toxic effects, in-hospital mortality, and readmission rates were similar for both groups. Multiple linear regression analysis identified randomization to the intervention group and female sex as the sole predictors of lower antibiotic charges. There was a trend toward a shorter length of stay for the intervention group (20 vs 24.7 days, P = .11). CONCLUSIONS: This is the first randomized study to evaluate whether antibiotic choices can be influenced in a cost-effective fashion without sacrificing patient safety. We demonstrate that 50% of patients initially treated with expensive parenteral antibiotics can have their regimens refined after 3 days of therapy and that these modifications result in good clinical outcomes with a substantial reduction in antibiotic expense.