4,792 research outputs found

    COOPER-framework: A Unified Standard Process for Non-parametric Projects

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    Practitioners assess performance of entities in increasingly large and complicated datasets. If non-parametric models, such as Data Envelopment Analysis, were ever considered as simple push-button technologies, this is impossible when many variables are available or when data have to be compiled from several sources. This paper introduces by the ‘COOPER-framework’ a comprehensive model for carrying out non-parametric projects. The framework consists of six interrelated phases: Concepts and objectives, On structuring data, Operational models, Performance comparison model, Evaluation, and Result and deployment. Each of the phases describes some necessary steps a researcher should examine for a well defined and repeatable analysis. The COOPER-framework provides for the novice analyst guidance, structure and advice for a sound non-parametric analysis. The more experienced analyst benefits from a check list such that important issues are not forgotten. In addition, by the use of a standardized framework non-parametric assessments will be more reliable, more repeatable, more manageable, faster and less costly.DEA, non-parametric efficiency, unified standard process, COOPER-framework.

    Selective Migration in New Towns: Influence on Regional Accountability in Early School Leaving

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    In an attempt to stop the rampant suburbanization, which countries experienced after World War II, a 'new town' policy was enrolled. As a major objective, and related to its origins, new towns were effective in attracting low and medium income households. Nowadays, cities and municipalities experience an increased accountability in which incentives are provided by 'naming and shaming'. This paper focuses on an issue where both historical and local policy come together: early school leaving. Using an iterative matching analysis, it suggests how to account for differences in population and regional characteristics. In other words, how to compare and interpret early school leaving in new towns in a more `fair' way. The results point out that (statistically) mitigating historical differences is necessary, even though this does not necessarily means that 'naming' is replaced by 'shaming'.Urban Economics; New Town; Early School Leaving; Naming and Shaming; Iterative Matching, Urban Planning

    Numerical periodic normalization for codim 2 bifurcations of limit cycles : computational formulas, numerical implementation, and examples

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    Explicit computational formulas for the coefficients of the periodic normal forms for codimension 2 (codim 2) bifurcations of limit cycles in generic autonomous ODEs are derived. All cases (except the weak resonances) with no more than three Floquet multipliers on the unit circle are covered. The resulting formulas are independent of the dimension of the phase space and involve solutions of certain boundary-value problems on the interval [0, T], where T is the period of the critical cycle, as well as multilinear functions from the Taylor expansion of the ODE right-hand side near the cycle. The formulas allow one to distinguish between various bifurcation scenarios near codim 2 bifurcations of limit cycles. Our formulation makes it possible to use robust numerical boundary-value algorithms based on orthogonal collocation, rather than shooting techniques, which greatly expands its applicability. The implementation is described in detail with numerical examples, where numerous codim 2 bifurcations of limit cycles are analyzed for the first time

    Block copolymers of poly(L-lactide) and poly(Δ-caprolactone) or poly(ethylene glycol) prepared by reactive extrusion

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    Blends of poly(L-lactide) (PLLA) and poly(-caprolactone) (PCL) were prepared in a co-rotating twin screw miniextruder (40 rpm, 200°). It was attempted to prepare multiblock copolymers by allowing a controlled number of transesterification reactions. Various cat-alysts (n-Bu3SnOMe, Sn(Oct)2, Ti(OBu)4, Y(Oct)3, para-toluene sulphonic acid) were introduced to promote these transesterification reactions. However, PLLA degradation by ring-closing depolymerization was the dominant reaction in every case. Alternatively, after showing that L-lactide can be conveniently polymerized in the extruder, L-lactide and hy-droxyl functionalized prepolymers of PCL or poly(ethylene glycol) (PEG) were fed to the extruder in the presence of stannous octoate. Monomer conversions of over 90% and effective transformation of all hydroxyl end groups present were generally reached. Di-and triblock copolymers could be prepared in this way with characteristics very similar to polymers prepared in a batch-type process, but with considerably reduced reaction times in a fashion, which is, in principle, scaleable to a continuous process for the production of such block copolymers

    The Living Rainforest Sustainable Greenhouses

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    The Living Rainforest (www.livingrainforest.org) is an educational charity that uses rainforest ecology as a metaphor for communicating general sustainability issues to the public. Its greenhouses and office buildings are to be renovated using the most sustainable methods currently available. This will be realised through construction of a high insulating greenhouse covering with a k-value of less than 2 Wm-2K-1, passive seasonal storage of excess summer solar energy in the ground by a ground source heat exchanger and exploitation of this low grade solar energy for heating in winter by a heat pump. In winter the heat pump will produce cold water to cool the ground allowing a passive cooling function in summer via the GSHE. It will be demonstrated that a GSHE is an alternative for an open aquifer in regions with no aquifer availability. The heat pump will deliver the heating baseload, the peak load will be delivered by a biomass boiler, fired with locally-sourced low-cost wood chips. It is expected that the energy saving will be about 75%, resulting in a major cost reduction. The low k-value of the covering is linked to a light transmission of 75 %. This is high enough for the demands of the vegetation in The Living Rainforest. Because the inner greenhouse climate demands are comparable to that of ornamentals, the results will be applicable to commercial ornamental production. In future low k-value coverings will also be available with high light transmission, allowing wider application of the results. This paper focuses on the correlation between k-value, light transmission and energy demand in order to investigate the trade-off between light transmittance (a major energy gain) and heat loss. The effects of these design parameters on storage and harvesting capacity are also considered but appear to have a low sensitivity. The renovated greenhouse site at The Living Rainforest will show that new greenhouses and ecology can be linked to sustainability and this will be communicated and demonstrated to the public

    Dimensions of invisibility: insights into the daily realities of persons with disabilities living in rural communities in India

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    Persons with disabilities in rural India do not have the opportunity to lead a self-determined life and be included in their community as required by the convention on the rights of persons with disabilities. To investigate their experience of living everyday life and the amount of agency they are able to exercise, in-depth interviews were undertaken. The Capability Approach (CA) was used to analyse the situation that was seen in terms of outcome of the interplay between internal and external factors resulting in loss of agency. The results show that the dependency they experience due to lack of adequate support to undertake activities and being completely dependent on the family places them in a vicious circle of ‘self-worthlessness’. Reducing the dependency disabled people face and changing perceptions of the community towards disability may break this circle. Points of Interest In rural India persons with disabilities are unable to live a self- determined life and to participate in home and community activities. The research shows that the interaction between personal, social and environmental factors makes it difficult for persons with disabilities to live a self-determined life and increase dependency. The dependency encountered, coupled with the negative attitude of the community towards disability, places the persons with disabilities in a vicious circle of ‘worthlessness’. The recommendations suggest reducing the dependency of persons with disabilities on their families, improving the perception of disability in the community and increasing self-esteem of persons with disabilities

    From Therapeutic Factors to Mechanisms of Change in the Creative Arts Therapies:A Scoping Review

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    Empirical studies in the creative arts therapies (CATs; i.e., art therapy, dance/movement therapy, drama therapy, music therapy, psychodrama, and poetry/bibliotherapy) have grown rapidly in the last 10 years, documenting their positive impact on a wide range of psychological and physiological outcomes (e.g., stress, trauma, depression, anxiety, and pain). However, it remains unclear how and why the CATs have positive effects, and which therapeutic factors account for these changes. Research that specifically focuses on the therapeutic factors and/or mechanisms of change in CATs is only beginning to emerge. To gain more insight into how and why the CATs influence outcomes, we conducted a scoping review (Nstudies = 67) to pinpoint therapeutic factors specific to each CATs discipline, joint factors of CATs, and more generic common factors across all psychotherapy approaches. This review therefore provides an overview of empirical CATs studies dealing with therapeutic factors and/or mechanisms of change, and a detailed analysis of these therapeutic factors which are grouped into domains. A framework of 19 domains of CATs therapeutic factors is proposed, of which the three domains are composed solely of factors unique to the CATs: “embodiment,” “concretization,” and “symbolism and metaphors.” The terminology used in change process research is clarified, and the implications for future research, clinical practice, and CATs education are discussed

    Cytotoxic Screening of Some Tanzania Medicinal Plants

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    East and Central African Journal of Pharmaceutical Sciences Vol.6(3) 2003: 52-5

    Cytotoxic activity of some Tanzanian medicinal plants

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    Thirty-three aqueous methanolic extracts obtained from thirty plant species, belonging to seventeen families were screened for cytotoxic activity against HeLa (Human cervical carcinoma) cells. The ability of the extracts (10 g/ml and 1 g/ml) to inhibit proliferation of HeLa cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) dye reduction assay. Extracts from roots of Agathisanthemum bojeri, Synaptolepis kirkii and Zanha africana and the leaf extract of Physalis peruviana at a concentration of 10 ”g/ml inhibited cell proliferation by 58.3 %, 68.1 %, 75.7 % and 91.8 %, respectively. The remaining 29 extracts exhibited no pronounced cytotoxic activity at the tested concentrations. It is worth investigating the four extracts, which showed pronounced cytotoxic activity so as to isolate and identify the compounds responsible for cytotoxic activity. Keywords: cytotoxic plants, Tanzanian medicinal plants, Agathisanthemum bojeri, Synaptolepis kirkii, Zanha africana, Physalis peruviana The East and Central African Journal of Pharmaceutical Sciences Vol. 8(2) 2005: 35-3
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