Dynamics of Content Quality in Collaborative Knowledge Production

We explore the dynamics of user performance in collaborative knowledge production by studying the quality of answers to questions posted on Stack Exchange. We propose four indicators of answer quality: answer length, the number of code lines and hyperlinks to external web content it contains, and whether it is accepted by the asker as the most helpful answer to the question. Analyzing millions of answers posted over the period from 2008 to 2014, we uncover regular short-term and long-term changes in quality. In the short-term, quality deteriorates over the course of a single session, with each successive answer becoming shorter, with fewer code lines and links, and less likely to be accepted. In contrast, performance improves over the long-term, with more experienced users producing higher quality answers. These trends are not a consequence of data heterogeneity, but rather have a behavioral origin. Our findings highlight the complex interplay between short-term deterioration in performance, potentially due to mental fatigue or attention depletion, and long-term performance improvement due to learning and skill acquisition, and its impact on the quality of user-generated content

Variability and nutritive compounds of guava (Psidium guajava L.)

Guava (Psidium guajava L.) is a tropical fruit plant. The study was conducted at three different altitudes in guava production center of Indonesia. The objectives of this research are to obtain information about the production and quality of guava at three locations by using manure applications. The study was conducted to guava plants at the age of 4 yr (first production). The study was designed according to the factorial design of 3 × 2 with 5 times replications. The first factor is the locations, which are the location-I (Pageruyung), location-II(Sukorejo) and location- III (Plantungan). The second factor is the provision of organic material of manure; without and with manure (2.5 t · ha–1). The data collected is the guava production (total production for four months tree), diameter, weight, flesh thickness, seeds weight, fruit acid content and sugar content. Result of research showed (1.) the interaction between the location and the addition of manure in the cultivation of guava increased its fruit production, weight, and the sugar content, (2.) the research locations have elevation and soil chemical content varies in fruit diameter, seeds weight, and fruit acid content, (3.) manure significantly increased fruit production, weight, diameter, flesh thickness and sugar content, but it did not increase seeds weight and it reduced the fruit acid content

Amateur content production, networked innovation and innovation policy

The central common feature of a number of recent technological developments (collectively referred to as Web 2.0) is collaborative production of content on an amateur basis, that is, for motives other than commercial reward. Amateur production of content generates significant external benefits that are shared by society in general. Indeed the amateur production of various types of content is probably more socially beneficial since it is typically given away free The individual and social benefits of such activity therefore justify public policy responses to the opportunity now before us.

On-farm influence of production patterns on total polyphenol content in peach

Peach production in France is constantly confronted with marketing problems due to a decrease in fruit consumption and increasing competition with neighbouring Mediterranean countries. The production of higher quality products using production methods such as organic farming (OF) appears to be a tangible way of differentiating and enhancing peach production. To test this hypothesis, an on-farm study was conducted in one of the major production areas in South-eastern France. Focussing on the peach cultivar, cv. Spring Lady®, paired comparisons were conducted between plots in OF and conventional farming (CF). Farmers' practices were identified and checked against crop measurements and performances (yield, sugar content, size classes) in 2004 (12 plots) and in 2005 (10 plots). Polyphenol contents were assessed as an additional component of fruit quality, using the Folin-Ciocalteu colorimetric method. Organic peaches have a higher polyphenol content at harvest. Contents were 4.8 times higher in 2004, whereas the same phenomenon was not observed in 2005. Levels of nitrogen, yield and tree vigour management appeared to be the key elements responsible for the synthesis of total polyphenols and sugar content This implies new opportunities for improving the nutritional quality of peaches, based on production methods

Carcass quality of organic pork

According to the Council Regulation (EC) No 1804/1999), organic livestock production is intended to ensure quality production rather than maximising production. In organic pig production, the availability of limited amino acids is the first limiting factor and the main reason why the performance capacity is clearly diminished compared to conventional production. In order to compensate for the lower productivity, quality production is a conditio sine qua none. Possibilities to improve the quality of organic pork were investigated in different feeding trials. Results from a first trial in 1999 showed that diets based on organic cereals and home grown grain legumes (faba beans, peas and lupines) have the potential to produce pork with a high intramuscular fat content (IMF) being a relevant but not the only factor effecting the sensorial quality of pork (Sundrum et al., 2000a). This result was confirmed in a second trial. Additionally, pork with a high IMF content (> 2,9%) was preferred by an expert panel compared to pork with a low IMF (Fischer, 2000). In a further trial using a dose-effect design with synthetic amino acids, the working hypothesis was supported that an unbalanced relation between essential and non limited amino acids could provoke the de-novo-synthesis of fatty acids in the muscle cell (not yet published). Summing up, there is reason for the assumption that specific diets have the potential to increase the IMF content of pork without increasing the back-fat content of carcass. However, the carcass quality has it’s price. Negative correlations between IMF content and muscle area as well as live-weight gain emphasize the existence of an antagonistic relationship between quantity and quality issues. The previous results do not necessarily lead to a simple device how to increase carcass quality (Sundrum et al., 2000b). Besides the IMF content there are various other aspects that have to be taken into account. The production of pork of high quality means a challenge that naturally can not be coped by all farmers. The production of high quality goes along with an increase in the production costs that have to be compensated for by premium prices. The willingness of consumers to pay premium prices for organic products is an excellent precondition to develop a premium line of production in combination with high process qualities concerning animal welfare and environmentally friendly production. The most important precondition is to remunerate the specific performance of the farmer and to guarantee the high quality standards offered to the consumer. (SUNDRUM, A., (2002): Carcass quality of organic pork. AFSSA – Journée d'Echanges sur l'Agriculture Biologique, 18 octobre 2002, p. 50-52

Sustainable intensification? Increased production diminishes omega-3 content of sheep milk

Intensifying agricultural production alters food composition, but this is often ignored when assessing system sustainability, yet it could compromise consumers’ health and the concept of ‘sustainable diets’. Here we consider milk composition from Mediterranean dairy sheep, finding inferior fatty acid (FA) profiles with respect to consumer health as a result of a more intensive system of production. Semi-intensive management did produce 57% more milk per ewe with 20% lower fat content, but inferior fat composition. Milk had a nutritionally poorer fatty acid (FA) profile, with 18% less omega-3 FA (n-3) (19% less long-chain n-3) and 7% less monounsaturated FA but 3% more saturated FA (9% higher in C14:0) concentrations compared with ewes under traditional, extensive management. Redundancy analysis identified close associations between fat composition and animal diets, particularly concentrate supplementation and grazing cultivated pasture - n-3 was associated with grazing diverse, native mountain pastures. The paper questions if identifying such key elements in traditional systems could be deployed for ‘sustainable intensification’ to maintain food quality whilst increasing output

Nuclear DNA and protein content evaluation in Taxus plant cell cultures using multiparameter flow cytometry

Plant cell cultures of Taxus provide the most reliable production methods for the anti-cancer drug paclitaxel. In order to comprehend the inherent culture heterogeneity and production variability in cell cultures, it is essential that the cellular metabolism is studied at the genomic level. Genomic stability in plant cell cultures is crucial as it affects cell growth and division, metabolite accumulation and protein synthesis. A rapid and efficient method to prepare nuclei suspensions from aggregated cell cultures of Taxus was employed. Methods were subsequently developed to simultaneously stain them for DNA and protein content using Propidium Iodide and Fluorescein Isothiocyanate respectively. Flow cytometry was used to analyze and quantify the DNA content and genome size of Taxus using known reference species as standards. Furthermore, their genomic stability was evaluated by correlating DNA content and genome size with cell size and complexity, protein content, and elicitation effects using multiparameter flow cytometry. These techniques to evaluate and correlate various culture characteristics can be very useful in designing superior bio processes for enhanced production.


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The investigation of heavy metal ion content in rock and coal production

Приведено олгляд методів визначення вмісту важких металів у вугіллі та продуктах вуглевидобутку. Виявлена доцільність використання НВЧ-поля та зниження температури озолення проб для підвищення точності визначення та зниження витрат часу на проведення аналізу.Приведен обзор методов определения тяжелых металлов в угле и продуктах угледобычи. Выявлена целесообразность использования СВЧ-поля и снижения температуры озоления проб для повышения точности определения и уменьшения затрат времени на проведения анализа.A review over the methods of heavy metals determination in coal and products of coal mining is present. Expediency of the use of microwave and declines of temperature for ash tests is educed for the exactness increase of determination and diminishing time for analysis