530 research outputs found
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<i>Aloe succotrina</i> (Asphodelaceae)
Aloe succotrina has a very long and complex taxonomic and nomenclatural history with wrong synonymy that is rivalled by few other aloes. This is mostly due to early authors wrongly assuming that this plant is from the Island of Socotra (Reynolds 1950). It has been in cultivation in Europe for over three hundred years, so consequently it is rather surprising that this iconic fynbos species has not featured in this journal until now
Framing stakeholder considerations and business sustainability efforts : a construct, its dimensions and items
Purpose â The purpose of this paper is twofold: to determine the extent to which companiesââą efforts of sustainable business practices consider stakeholders within their organisations, business networks, the marketplace and society, and to develop and test a stakeholder construct in the context of companiesââą business sustainability efforts within their business networks, the marketplace and society by identifying underlying dimensions and items. Design/methodology/approach â A mixed-method approach was used. First, qualitative research involving a case study approach was followed so as to describe how companies in different industries in Norway implement and manage sustainable business practices. This was followed by a quantitative research phase to empirically measure and test a stakeholder construct in the context of business sustainability efforts, which is reported here. Findings â The results report both an initial factor solution as well as a refined factor solution. The factor analyses confirmed five stakeholder dimensions related to business sustainability in a cross-industry sample of organisations, their business networks, marketplace and society. These include: the focal company, downstream stakeholders, societal stakeholders, market stakeholders and upstream stakeholders. The results indicate satisfactory convergent, discriminant and nomological validity, as well as reliability of each dimension. Research limitations/implications â The study provides a stakeholder construct in the context of business sustainability efforts in focal companies and their business networks, the marketplace and society, based upon five common dimensions. The multi-dimensional framework may be used in both qualitative and quantitative research in future. It may also be used to assess stakeholdersââą business sustainability efforts. Practical implications â The multi-dimensional framework is useful for practitioners to obtain an indication of stakeholdersââą business sustainability efforts in relation to focal companies and their business networks, the marketplace and society. Originality/value â The study provides a general stakeholder construct in the context of business sustainability efforts in business networks, the marketplace and society. The proposed framework can be incorporated in further studies and could be used to assess the general status of stakeholdersââą sustainability efforts in their networks, the marketplace and society
Scattering length of the ground state Mg+Mg collision
We have constructed the X 1SIGMAg+ potential for the collision between two
ground state Mg atoms and analyzed the effect of uncertainties in the shape of
the potential on scattering properties at ultra-cold temperatures. This
potential reproduces the experimental term values to 0.2 inverse cm and has a
scattering length of +1.4(5) nm where the error is prodominantly due to the
uncertainty in the dissociation energy and the C6 dispersion coefficient. A
positive sign of the scattering length suggests that a Bose-Einstein condensate
of ground state Mg atoms is stable.Comment: 15 pages, 3 figures, Submitted Phys. Rev.
BDNF Val66Met and DRD2 Taq1A polymorphisms interact to influence PTSD symptom severity: A preliminary investigation in a South African population
BACKGROUND: We evaluated the role that selected variants in serotonin transporter (5-HTT), dopamine receptor 2 (DRD2) and brain-derived neurotrophic factor (BDNF) genes play in PTSD symptom severity in an at-risk population. We also investigated the interaction between the genetic variants to determine whether these variables and the interactions between the variables influenced the severity of PTSD symptoms.
METHODS: PTSD symptoms were quantitatively assessed using the Davidson Trauma Scale (DTS) in 150 participants from an at-risk South African population. All participants were genotyped for the 5-HTTLPR, DRD2 Taq1A and BDNF Val66Met polymorphisms. Geneâgene interactions were investigated using various linear models. All analyses were adjusted for age, gender, major depressive disorder diagnosis, level of resilience, level of social support and alcohol dependence.
RESULTS: A significant interaction effect between DRD2 Taq1A and BDNF Val66Met variants on DTS score was observed. On the background of the BDNF Val66Val genotype, DTS score increased significantly with the addition of a DRD2 Taq1A A1 allele. However, on the BDNF Met66 allele background, the addition of an A1 allele was found to reduce total DTS score.
CONCLUSIONS: This study provides preliminary evidence for an epistatic interaction between BDNF Val66Met and DRD2 Taq1A polymorphisms on the severity of PTSD symptoms, where both too little and too much dopamine can result in increased PTSD symptom severity.Web of Scienc
Morphology and function of dog arterial grafts preserved in UW-solution
Objectives:To assess the function of arterial grafts after prolonged preservation in the University of Wisconsin solution (UW), in vitro and in vivo.Methods:Carotid arteries were harvested from dogs and stored for 1â21 days at 4°C in UW (n = 10) or in PBS (0.9% NaCl, pH 7.4), (PBS) (n = 10). Slices were examined by lightmicroscopy (LM) and scanning electron microscopy (SEM). For viability testing, specimens were connected to an isometric force transducer (2 Ă n = 9). Contractile and relaxation responses were examined by adding phenylephrine (200ÎŒM) and metacholine (200ÎŒM), respectively. For in vivo studies (n = 41), 2.5cm carotid artery segments were implanted orthotopically, as autografts and allografts, after 14 days of storage in UW or in PBS. Autologous veins were used as controls. After 28 days or 56 days, arteriography was performed and the grafts were excised for LM and SEM.Results:The arterial endothelial layer remained intact after up to 14 days of storage in UW. In PBS, the endothelium was lost after 3 days. The functional response after 14 days storage in UW was approximately 50% vs. 0% after 14 days in PBS. In the autografts, total patencies (28 days + 56 days) were 100% (8/8) and 63% (5/8) for UW and PBS stored grafts, respectively. In the allografts, the UW and PBS preserved grafts showed total patencies of 86% (12/14) and 83% (5/6), respectively. Microscopically, the allografts showed fibrotic degeneration.Conclusions:Arteries are well preserved in UW up to 14 days of storage. Arterial autografts preserved in UW showed good patency and better integrity of the vessel wall after implantation, than grafts stored in PBS or allografts (without immunosuppressive therapy)
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Aloiampelos ciliaris var. ciliaris. Asphodelaceae: Alooideae
Aloiampelos ciliaris is the type of a new genus of just seven species separated from Aloe in 2013 to accommodate the scrambling South African aloes. The history, taxonomy, distribution, ecology, cytology and cultivation of this species are all discussed in detail. This species is unique for Southern Africa in having a hexaploid chromosome count of 2n=42. The leaf structure is also distinctive with an amplexicaul base bearing conspicuous white cilia. It is endemic to the Eastern Cape Province
Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
Quantum ESPRESSO is an integrated suite of computer codes for
electronic-structure calculations and materials modeling, based on
density-functional theory, plane waves, and pseudopotentials (norm-conserving,
ultrasoft, and projector-augmented wave). Quantum ESPRESSO stands for "opEn
Source Package for Research in Electronic Structure, Simulation, and
Optimization". It is freely available to researchers around the world under the
terms of the GNU General Public License. Quantum ESPRESSO builds upon
newly-restructured electronic-structure codes that have been developed and
tested by some of the original authors of novel electronic-structure algorithms
and applied in the last twenty years by some of the leading materials modeling
groups worldwide. Innovation and efficiency are still its main focus, with
special attention paid to massively-parallel architectures, and a great effort
being devoted to user friendliness. Quantum ESPRESSO is evolving towards a
distribution of independent and inter-operable codes in the spirit of an
open-source project, where researchers active in the field of
electronic-structure calculations are encouraged to participate in the project
by contributing their own codes or by implementing their own ideas into
existing codes.Comment: 36 pages, 5 figures, resubmitted to J.Phys.: Condens. Matte
Quantifying culture gaps between physicians and managers in Dutch hospitals: a survey
Background: The demands in hospitals for safety and quality, combined with limitations in financing health care require effective cooperation between physicians and managers. The complex relationship between both groups has been described in literature. We aim to add a perspective to literature, by developing a questionnaire which provides an opportunity to quantitatively report and elaborate on the size and content of differences between physicians and managers. Insight gained from use of the questionnaire might enable us to reflect on these differences and could provide practical tools to improve cooperation between physicians and managers, with an aim to enhance hospital performance.\ud
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Methods: The CG-Questionnaire was developed by adjusting, pre-testing, and shortening Kralewski's questionnaire, and appeared suitable to measure culture gaps. It was shortened by exploratory factor analysis, using principal-axis factoring extraction with Varimax rotation. The CG-Questionnaire was sent to all physicians and managers within 37 Dutch general hospitals. ANOVA and paired sample T-tests were used to determine significant differences between perceptions of daily work practices based in both professional cultures; culture gaps. The size and content of culture gaps were determined with descriptive statistics.\ud
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Results: The total response (27%) consisted of 929 physicians and 310 managers. The Cronbachs alpha's were 0.70 - 0.79. Statistical analyses showed many differences; culture gaps were found in the present situation; they were even larger in the preferred situation. Differences between both groups can be classified into three categories: (1) culture gaps in the present situation and not in the preferred, (2) culture gaps in the preferred situation and not in the present, and (3) culture gaps in both situations.\ud
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Conclusions: With data from the CG-Questionnaire it is now possible to measure the size and content of culture gaps between physicians and managers in hospitals. Results gained with the CG-Questionnaire enables hospitals to reflect on these differences. Combining the results, we distinguished three categories of increasing complexity. We linked these three categories to three methods from intergroup literature (enhanced information, contact and ultimately meta cognition) which could help to improve the cooperation between physicians and managers
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