101 research outputs found

    Characterisation of stable isotopes to identify residence times and runoff components in two meso-scale catchments in the Abay/Upper Blue Nile basin, Ethiopia

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    Measurements of the stable isotopes oxygen-18 (<sup>18</sup>O) and deuterium (<sup>2</sup>H) were carried out in two meso-scale catchments, Chemoga (358 km<sup>2</sup>) and Jedeb (296 km<sup>2</sup>) south of Lake Tana, Abay/Upper Blue Nile basin, Ethiopia. The region is of paramount importance for the water resources in the Nile basin, as more than 70% of total Nile water flow originates from the Ethiopian highlands. Stable isotope compositions in precipitation, spring water and streamflow were analysed (i) to characterise the spatial and temporal variations of water fluxes; (ii) to estimate the mean residence time of water using a sine wave regression approach; and (iii) to identify runoff components using classical two-component hydrograph separations on a seasonal timescale. <br><br> The results show that the isotopic composition of precipitation exhibits marked seasonal variations, which suggests different sources of moisture generation for the rainfall in the study area. The Atlantic–Indian Ocean, Congo basin, Upper White Nile and the Sudd swamps are the potential moisture source areas during the main rainy (summer) season, while the Indian–Arabian and Mediterranean Sea moisture source areas during little rain (spring) and dry (winter) seasons. The spatial variation in the isotopic composition is influenced by the amount effect as depicted by moderate coefficients of determination on a monthly timescale (<i>R</i><sup>2</sup> varies from 0.38 to 0.68) and weak regression coefficients (<i>R</i><sup>2</sup> varies from 0.18 to 0.58) for the altitude and temperature effects. A mean altitude effect accounting for −0.12&permil;/100 m for <sup>18</sup>O and −0.58&permil;/100 m for <sup>2</sup>H was discernible in precipitation isotope composition. <br><br> Results from the hydrograph separation on a seasonal timescale indicate the dominance of event water, with an average of 71 and 64% of the total runoff during the wet season in the Chemoga and Jedeb catchments, respectively. <br><br> Moreover, the stable isotope compositions of streamflow samples were damped compared to the input function of precipitation for both catchments. This damping was used to estimate mean residence times of stream water of 4.1 and 6.0 months at the Chemoga and Jedeb catchment outlets, respectively. Short mean residence times and high fractions of event water components recommend catchment management measures aiming at reduction of overland flow/soil erosion and increasing of soil water retention and recharge to enable sustainable development in these agriculturally dominated catchments

    A Theoretical Simulation of Deformed Carbon Nanotubes with Adsorbed Metal Atoms: Enhanced Reactivity by Deformation

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    First-principles simulations were performed to investigate reaction of carbon nanotubes with adsorbed metal atoms. Mechanical modification of their structures enhances chemical reactivity of carbon nanotubes. Adsorption of a tungsten, tantalum, or niobium atom on a (5, 0) nanotube with a Stone-Wales defect was shown to have characteristically strong chemisorption. Bond-breaking in the carbon-carbon network and formation of a local metal-carbon complex were observed during the simulation. Adsorption of W, Ta, Ni or Mo on a twisted (5, 0) nanotube showed a preferred breaking of several bonds, even creating an opening in the wall. The enhanced chemical reactivity of deformed nanotubes is characterized by formation of a metal-carbon complex. Applications of the reaction are suggested.Comment: 12 pages, 4 figure

    One job, one deal...or not: do generations respond differently to psychological contract fulfillment?

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    This paper investigates generational differences in the relations between psychological contract fulfillment and work attitudes. Data were collected from a sample of 909 employees in the Dutch service sector. Structural equation modeling analyses were used to test the moderating effects of generational differences on the influence of psychological contract fulfillment on affective commitment and turnover intention. The relationship between psychological contract fulfillment and these work outcomes was moderated by generational differences. Furthermore, results indicate that different generations respond differently to different aspects of psychological contract fulfillment, such as career development, job content, organizational policies, social atmosphere and rewards. The study provides evidence that generational differences impact the reciprocal relationship between employer and employee. Results from this study suggest that Baby Boomers and Generation X may be more motivated by social atmosphere, whereas Generation Y may be more motivated by job content and career development. Fair organizational policies are particularly motivating to Generation X, and providing rewards, though more important to Generation Y, seem mostly unrelated to work outcomes. This article is the first to study the moderation of generational differences in the relationships between psychological contract fulfillment and work outcomes

    Perinatal palliative care in sub-Saharan Africa: recommendations for practice, future research, and guideline development

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    Worldwide, sub-Saharan Africa has the highest burden of global neonatal mortality (43%) and neonatal mortality rate (NMR): 27 deaths per 1,000 live births. The WHO recognizes palliative care (PC) as an integral, yet underutilized, component of perinatal care for pregnancies at risk of stillbirth or early neonatal death, and for neonates with severe prematurity, birth trauma or congenital anomalies. Despite bearing a disproportionate burden of neonatal mortality, many strategies to care for dying newborns and support their families employed in high-income countries (HICs) are not available in low-and-middle-income countries (LMICs). Many institutions and professional societies in LMICs lack guidelines or recommendations to standardize care, and existing guidelines may have limited adherence due to lack of space, equipment, supplies, trained professionals, and high patient load. In this narrative review, we compare perinatal/neonatal PC in HICs and LMICs in sub-Saharan Africa to identify key areas for future, research-informed, interventions that might be tailored to the local sociocultural contexts and propose actionable recommendations for these resource-deprived environments that may support clinical care and inform future professional guideline development

    Feedback as intervention for team learning in virtual teams: the role of team cohesion and personality

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    Scholars and practitioners agree that virtual teams (VTs) have become commonplace in today's digital workplace. Relevant literature argues that learning constitutes a significant contributor to team member satisfaction and performance, and that, at least in face-to-face teams, team cohesion fosters team learning. Given the additional challenges VTs face, e.g. geographical dispersion, which are likely have a negative influence on cohesion, in this paper we shed light on the relationship between team cohesion and team learning. We adopted a quantitative approach and studied 54 VTs in our quest to understand the role of feedback in mediating this relationship and, more specifically, the role of personality traits in moderating the indirect effect of team feedback and guided reflection intervention on TL through team cohesion within the VT context. Our findings highlight the importance of considering aspects related to the team composition when devising intervention strategies for VTs, and provide empirical support for an interactionist model between personality and emergent states such as cohesion. Implications for theory and practice are also discussed

    Large-Scale Controls of the Surface Water Balance Over Land-Insights From a Systematic Review and Meta-Analysis

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    The long-term surface water balance over land is described by the partitioning of precipitation (P) into runoff and evapotranspiration (ET), and is commonly characterized by the ratio ET/P. The ratio between potential evapotranspiration (PET) and P is explicitly considered to be the primary control of ET/P within the Budyko framework, whereas all other controls are often integrated into a single parameter, ω. Although the joint effect of these additional controlling factors of ET/P can be significant, a detailed understanding of them is yet to be achieved. This study therefore introduces a new global dataset for the long-term mean partitioning of P into ET and runoff in 2733 catchments, which is based on in-situ observations and assembled from a systematic examination of peer-reviewed studies. A total of 26 controls of ET/P that are proposed in the literature are assessed using the new dataset. Results reveal that: (i) factors controlling ET/P vary between regions with different climate types; (ii) controls other than PET/P explain at least 35% of the ET/P variance in all regions, and up to ∼90% in arid climates; (iii) among these, climate factors and catchment slope dominate over other landscape characteristics; and (iv) despite the high attention that vegetation-related indices receive as controls of ET/P, they are found to play a minor and often non-significant role. Overall, this study provides a comprehensive picture on factors controlling the partitioning of P, with valuable insights for model development, watershed management, and the assessment of water resources around the globe

    In Pursuit of Impact: How Psychological Contract Research Can Make the Work-World a Better Place

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    This paper is the result of the collective work undertaken by a group of Psychological Contract (PC) and Sustainability scholars from around the world, following the 2023 Bi-Annual PC Small Group Conference (Kedge Business School, Bordeaux, France). As part of the conference, scholars engaged in a workshop designed to generate expert guidance on how to aid the PC field to be better aligned with the needs of practice, and thus, impact the creation and maintenance of high-quality and sustainable exchange processes at work. In accordance with accreditation bodies for higher education, research impact is not limited to academic papers alone but also includes practitioners, policymakers, and students in its scope. This paper therefore incorporates elements from an impact measurement tool for higher education in management so as to explore how PC scholars can bolster the beneficial influence of PC knowledge on employment relationships through different stakeholders and means. Accordingly, our proposals for the pursuit of PC impact are organized in three parts: (1) research, (2) practice and society, and (3) students. Further, this paper contributes to the emerging debate on sustainable PCs by developing a construct definition and integrating PCs with an ‘ethics of care’ perspective

    Linking Distributive and Procedural Justice to Employee Engagement Through Social Exchange: A Field Study in India

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    Research linking justice perceptions to employee outcomes has referred to social exchange as its central theoretical premise. We tested a conceptual model linking distributive and procedural justice to employee engagement through social exchange mediators, namely, perceived organizational support and psychological contract, among 238 managers and executives from manufacturing and service sector firms in India. Findings suggest that perceived organizational support mediated the relationship between distributive justice and employee engagement, and both perceived organizational support and psychological contract mediated the relationship between procedural justice and employee engagement. Theoretical and practical implications with respect to organizational functions are discussed

    Antibiotic use on paediatric inpatients in a teaching hospital in the Gambia, a retrospective study

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    Background: Antibiotics are useful but increasing resistance is a major problem. Our objectives were to assess antibiotic use and microbiology testing in hospitalized children in the Gambia. Methods: We conducted a retrospective analysis of paediatric inpatient data at The Edward Francis Small Teaching Hospital in Banjul, The Gambia. We extracted relevant data from the admission folders of all patients (aged >28 days to 15 years) admitted in 2015 (January-December), who received at least one antibiotic for 24 h. We also reviewed the microbiology laboratory record book to obtain separate data for the bacterial isolates and resistance test results of all the paediatric inpatients during the study period. Results: Over half of the admitted patients received at least one antibiotic during admission (496/917) with a total consumption of 670.7 Days of Antibiotic Therapy/1000 Patient-Days. The clinical diagnoses included an infectious disease for 398/496, 80.2% of the patients on antibiotics, pneumonia being the most common (184/496, 37.1%). There were 51 clinically relevant bacterial isolates, Klebsiella species being the most common (12/51, 23.5%), mainly from urine (11/12, 91.7%). Antibiotic resistance was mainly to ampicillin (38/51, 74.5%), mainly reported as Coliform species 11/51, 21.6%. Conclusions: More than half of the admitted patients received antibiotics. The reported antibiotic resistance was highest to the most commonly used antibiotics such as ampicillin. Efforts to maximize definitive antibiotic indication such as microbiological testing prior to start of antibiotics should be encouraged where possible for a more rational antibiotic use
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