1,343 research outputs found

    Response Mixture Modeling of Intraindividual Differences in Responses and Response Times to the Hungarian WISC-IV Block Design Test

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    Response times may constitute an important additional source of information about cognitive ability as it enables to distinguishing between different intraindividual response processes. In this paper, we present a method to disentangle interindividual variation from intraindividual variation in the responses and response times of 978 subjects to the 14 items of the Hungarian WISC-IV Block Design test. It is found that faster and slower responses differ in their measurement properties suggesting that there are intraindivual differences in the response processes adopted by the subjects

    Josephson supercurrent in a topological insulator without a bulk shunt

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    A Josephson supercurrent has been induced into the three-dimensional topological insulator Bi1.5Sb0.5Te1.7Se1.3. We show that the transport in Bi1.5Sb0.5Te1.7Se1.3 exfoliated flakes is dominated by surface states and that the bulk conductivity can be neglected at the temperatures where we study the proximity induced superconductivity. We prepared Josephson junctions with widths in the order of 40 nm and lengths in the order of 50 to 80 nm on several Bi1.5Sb0.5Te1.7Se1.3 flakes and measured down to 30 mK. The Fraunhofer patterns unequivocally reveal that the supercurrent is a Josephson supercurrent. The measured critical currents are reproducibly observed on different devices and upon multiple cooldowns, and the critical current dependence on temperature as well as magnetic field can be well explained by diffusive transport models and geometric effects

    Dynamics Among Borderline Personality and Anxiety Features in Psychotherapy Outpatients: An Exploration of Nomothetic and Idiographic Patterns

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    Borderline personality disorder (BPD) involves instability in self-concept, emotions, and behavior. However, the dynamic, longitudinal relations among BPD symptoms and between these symptoms and other problematic emotional experiences are poorly understood. It is also unclear whether these dynamics are the same across persons (including across diagnostic boundaries), specific to individuals with BPD, or idiographic. The current study uses ecological momentary assessment and Group Iterative Multiple Model Estimation (GIMME), a novel, data-driven approach to identifying dynamic patterns in time-series data at group, subgroup, and individual levels, to investigate the dynamic connections among select features of BPD (anger, impulsivity, and identity disturbance) and anxiety-related experiences. Forty-two psychiatric outpatients diagnosed with BPD (n = 27) or with an anxiety disorder, but not BPD (n = 15) rated their anger, identity disturbance, impulsivity, anxiety, stress, and calmness states six times per day for 21 days, providing a total of 4,699 surveys. Only one dynamic link between symptoms was identified that applied at the group level, and GIMME did not reveal stable subgroups of individuals with distinct symptom dynamics. Instead, these dynamics differed from individual to individual. These results suggest that connections among these BPD and anxiety symptoms do not depend on diagnosis and are somewhat idiographic. Case examples are used to illustrate the clinical utility of within-person symptom models as a supplement to traditional diagnostic information

    In silico evolution of diauxic growth

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    The glucose effect is a well known phenomenon whereby cells, when presented with two different nutrients, show a diauxic growth pattern, i.e. an episode of exponential growth followed by a lag phase of reduced growth followed by a second phase of exponential growth. Diauxic growth is usually thought of as a an adaptation to maximise biomass production in an environment offering two or more carbon sources. While diauxic growth has been studied widely both experimentally and theoretically, the hypothesis that diauxic growth is a strategy to increase overall growth has remained an unconfirmed conjecture. Here, we present a minimal mathematical model of a bacterial nutrient uptake system and metabolism. We subject this model to artificial evolution to test under which conditions diauxic growth evolves. As a result, we find that, indeed, sequential uptake of nutrients emerges if there is competition for nutrients and the metabolism/uptake system is capacity limited. However, we also find that diauxic growth is a secondary effect of this system and that the speed-up of nutrient uptake is a much larger effect. Notably, this speed-up of nutrient uptake coincides with an overall reduction of efficiency. Our two main conclusions are: (i) Cells competing for the same nutrients evolve rapid but inefficient growth dynamics. (ii) In the deterministic models we use here no substantial lag-phase evolves. This suggests that the lag-phase is a consequence of stochastic gene expression

    Predictors of patients’ choices for breast-conserving therapy or mastectomy: a prospective study

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    A study was undertaken to describe the treatment preferences and choices of patients with breast cancer, and to identify predictors of undergoing breast-conserving therapy (BCT) or mastectomy (MT). Consecutive patients with stage I/II breast cancer were eligible. Information about predictor variables, including socio-demographics, quality of life, patients' concerns, decision style, decisional conflict and perceived preference of the surgeon was collected at baseline, before decision making and surgery. Patients received standard information (n = 88) or a decision aid (n = 92) as a supplement to support decision making. A total of 180 patients participated in the study. In all, 72% decided to have BCT (n = 123); 28% chose MT (n = 49). Multivariate analysis showed that what patients perceived to be their surgeons' preference and the patients' concerns regarding breast loss and local tumour recurrence were the strongest predictors of treatment preference. Treatment preferences in itself were highly predictive of the treatment decision. The decision aid did riot influence treatment choice. The results of this study demonstrate that patients' concerns and their perceptions of the treatment preferences of the physicians are important factors in patients' decision making. Adequate information and communication are essential to base treatment decisions on realistic concerns, and the treatment preferences of patients, (C) 2004 Cancer Research U

    Variation in abundances of common bird species associated with roads

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    1. The global road network, currently over 45 million lane-km in length, is expected to reach 70 million lane-km by 2050, while the number of vehicles utilising it is expected to double. Roads have been shown to affect a range of wildlife, including birds, but most studies have been relatively small scale. 2. We use data from across Great Britain to analyse the relationships between roads and the spatial distributions of bird populations. We model counts of 51 common and widespread species from the U.K. Breeding Bird Survey in relation to road exposure, which we calculated for each count site using the density, distance and traffic volume of all roads within a 5 km radius. In these models, we incorporate other factors known to affect bird populations, including agricultural intensity, human population, habitat and climate. Importantly, we also account for differences in detectability of birds near to roads. 3. The abundances of 30 species were strongly significantly related to exposure to either major or minor roads. Species were generally in higher abundances with increasing exposure to minor roads (20/28). In contrast, most significant associations between major road exposure and bird abundance were negative (7/8). 4. For species with significant effects of road exposure, we assessed how estimated abundance changed across the central 50% of road exposure experienced for each species. The mean decrease in abundance was 19% and the mean increase was 47%. These changes in bird abundance were up to half as large as those associated with increasing agricultural intensity, a factor often cited as a major cause of bird population changes. 5. Synthesis and applications. Our research shows many species to vary in abundance with increasing road exposure. This suggests that roads may modify bird populations on a national scale and that their potential as drivers of biodiversity change should not be overlooked. Our work highlights the need for appropriate mitigation of roads, particularly in areas important for avian biodiversity. This could include efforts to reduce impacts of road noise and/or collisions, such as reduced speed limits or quieter road surfaces in sensitive areas

    Determining Contingencies in the Management of Construction Projects

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    [EN] This research describes the managerial approaches that contractors follow to determine different types of contingencies in construction project management. Two large Spanish general contractors were selected for an in-depth analysis. Interviews and surveys were conducted with six additional companies to explore the external validity of the findings. Managers constrain time and cost buffers through project objectives, applying heuristics to determine inventory buffers. The management of capacity buffers is entrusted to subcontractors. The contractors take advantage of scope and quality buffers to meet project objectives but rarely share these buffers with the owner, unless the owner is an internal client.Ortiz-González, JI.; Pellicer, E.; Molenaar, KR. (2019). Determining Contingencies in the Management of Construction Projects. Project Management Journal. 50(2):226-242. https://doi.org/10.1177/8756972819827389S226242502Adafin, J., Wilkinson, S., Rotimi, J. O. 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Budgeting Owner’s Construction Contingency. Journal of Construction Engineering and Management, 133(7), 492-497. doi:10.1061/(asce)0733-9364(2007)133:7(492)Hällgren, M., & Wilson, T. L. (2008). The nature and management of crises in construction projects: Projects-as-practice observations. International Journal of Project Management, 26(8), 830-838. doi:10.1016/j.ijproman.2007.10.005Harbuck R. H. (2004). Competitive bidding for highway construction projects (pp. ES91–ES94). Morgantown, WV: AACE International Transactions.HORMAN, M., & KENLEY, R. (1998). Process Dynamics: Identifying a Strategy for the Deployment of Buffers in Building Projects. International Journal of Logistics Research and Applications, 1(3), 221-237. doi:10.1080/13675569808962049Horman, M. J., & Thomas, H. R. (2005). Role of Inventory Buffers in Construction Labor Performance. 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Schedule and Cost Buffer Sizing: How to Account for the Bias between Project Performance and Your Model. Project Management Journal, 34(2), 34-47. doi:10.1177/875697280303400205Lee, S., Peña-Mora, F., & Park, M. (2006). Reliability and Stability Buffering Approach: Focusing on the Issues of Errors and Changes in Concurrent Design and Construction Projects. Journal of Construction Engineering and Management, 132(5), 452-464. doi:10.1061/(asce)0733-9364(2006)132:5(452)Oviedo-Haito, R. J., Jiménez, J., Cardoso, F. F., & Pellicer, E. (2014). Survival Factors for Subcontractors in Economic Downturns. Journal of Construction Engineering and Management, 140(3), 04013056. doi:10.1061/(asce)co.1943-7862.0000811Pellicer, E., Sanz, M. A., Esmaeili, B., & Molenaar, K. R. (2016). Exploration of Team Integration in Spanish Multifamily Residential Building Construction. Journal of Management in Engineering, 32(5), 05016012. doi:10.1061/(asce)me.1943-5479.0000438Pellicer, E., & Victory, R. (2006). 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