15 research outputs found
Temporary staffing services: a data mining perspective
Research on the temporary staffing industry discusses different topics ranging from workplace safety to the internationalization of temporary labor. However, there is a lack of data mining studies concerning this topic. This paper meets this void and uses a financial dataset as input for the estimated models. Bagged decision trees were utilized to cope with the high dimensionality. Two bagged decision trees were estimated: one using the whole dataset and one using the top 12 predictors. Both had the same predictive performance. This means we can highly reduce the computational complexity, without losing accuracy
Temporary staffing services: a data mining perspective
Research on the temporary staffing industry discusses different topics ranging from workplace safety to the internationalization of temporary labor. However, there is a lack of data mining studies concerning this topic. This paper meets this void and uses a financial dataset as input for the estimated models. Bagged decision trees were utilized to cope with the high dimensionality. Two bagged decision trees were estimated: one using the whole dataset and one using the top 12 predictors. Both had the same predictive performance. This means we can highly reduce the computational complexity, without losing accuracy
The cell envelope structure of cable bacteria
Cable bacteria are long, multicellular micro-organisms that are capable of transporting electrons from cell to cell along the longitudinal axis of their centimeter-long filaments. The conductive structures that mediate this long-distance electron transport are thought to be located in the cell envelope. Therefore, this study examines in detail the architecture of the cell envelope of cable bacterium filaments by combining different sample preparation methods (chemical fixation, resin-embedding, and cryo-fixation) with a portfolio of imaging techniques (scanning electron microscopy, transmission electron microscopy and tomography, focused ion beam scanning electron microscopy, and atomic force microscopy). We systematically imaged intact filaments with varying diameters. In addition, we investigated the periplasmic fiber sheath that remains after the cytoplasm and membranes were removed by chemical extraction. Based on these investigations, we present a quantitative structural model of a cable bacterium. Cable bacteria build their cell envelope by a parallel concatenation of ridge compartments that have a standard size. Larger diameter filaments simply incorporate more parallel ridge compartments. Each ridge compartment contains a similar to 50 nm diameter fiber in the periplasmic space. These fibers are continuous across cell-to-cell junctions, which display a conspicuous cartwheel structure that is likely made by invaginations of the outer cell membrane around the periplasmic fibers. The continuity of the periplasmic fibers across cells makes them a prime candidate for the sought-after electron conducting structure in cable bacteria
The Cell Envelope Structure of Cable Bacteria
Cable bacteria are long, multicellular micro-organisms that are capable of transporting electrons from cell to cell along the longitudinal axis of their centimeter-long filaments. The conductive structures that mediate this long-distance electron transport are thought to be located in the cell envelope. Therefore, this study examines in detail the architecture of the cell envelope of cable bacterium filaments by combining different sample preparation methods (chemical fixation, resin-embedding, and cryo-fixation) with a portfolio of imaging techniques (scanning electron microscopy, transmission electron microscopy and tomography, focused ion beam scanning electron microscopy, and atomic force microscopy). We systematically imaged intact filaments with varying diameters. In addition, we investigated the periplasmic fiber sheath that remains after the cytoplasm and membranes were removed by chemical extraction. Based on these investigations, we present a quantitative structural model of a cable bacterium. Cable bacteria build their cell envelope by a parallel concatenation of ridge compartments that have a standard size. Larger diameter filaments simply incorporate more parallel ridge compartments. Each ridge compartment contains a ~50 nm diameter fiber in the periplasmic space. These fibers are continuous across cell-to-cell junctions, which display a conspicuous cartwheel structure that is likely made by invaginations of the outer cell membrane around the periplasmic fibers. The continuity of the periplasmic fibers across cells makes them a prime candidate for the sought-after electron conducting structure in cable bacteria
Using web data for acquiring profitable customers
The proposed research goal is to assist sales reps in the sales process by predicting the acquisition of profitable potential customers. It investigates the predictive performance of two sources of data: web data and commercially available data. It also investigates the performance of different data mining techniques. Results show that bagged decision trees have the highest accuracy. Web data is better in predicting profitability than commercial data, but combining both is even better
People believe that naturalistic enclosures make animals happier
Zoo enclosure designers should aim to offer behavioural opportunities that allow animals to enhance their quality of life. This can be achieved through a âbehavioural engineering approachâ in which artificial devices can be used, or through the ânaturalistic approachâ in which the wild environment is mimicked maximally. We hypothesized that the visitorsâ perception of the animalsâ happiness or wellbeing is influenced by enclosure design. In an online query, we showed pictures of natural versus unnatural looking enclosures for bonobos and we asked to score happiness on a 7-point scale, following an existing 4 item questionnaire, used to score subjective wellbeing in apes. A linear mixed model was applied with individual score as response value, respondent ID as random effect and enclosure type (natural or unnatural) as fixed effect. Respondents gave a significantly higher happiness score to more natural enclosures (df=1, p<0.0001). In more natural enclosures, they thought the bonobos would experience positive emotions during a longer period (df=1; p<0.0001), they gave a higher score to the degree in which they estimated the animals to be successful at fulfilling their needs (df=1; df=0.0001), and they thought they themselves would be happier if they were the animal during one week in that enclosure (df=1, p<0.0001). For each of the four questions, all nine pairwise comparisons of natural versus unnatural enclosures showed that the differences were significant (df=200, p<0.00001) for happiness score, duration of happiness, and happiness if the respondent would be the animal. Similarly, all pairwise comparisons differed significantly for âefficiency to fulfil their needsâ, except for the comparison of the pictures of a natural but relatively empty grassy area and an unnatural indoor enclosure with climbing structures (df=200, p<0.351), indicating a rough understanding of great apesâ climbing needs. Overall, people feel that naturalistic looking enclosures make bonobos happier. Whether their behavioural and psychological needs are met more efficiently in naturalistic enclosures needs to be assessed separately.status: publishe