bluuebunny/crossref_metadata_2025 huggingface dataset:
Linking the Impact of IT Investments to Productivity and Profitability
Authors: Rao Mohan P. , Mandal Purnendu
Published: September 2012

Implementing IT (information technology) systems such as ERP (enterprise resource planning) requires huge investments. Measuring the impact of these investments on productivity and profitability is extremely important for business managers. Many studies have failed to show the direct relationship between IT investments, organizational productivity and profitability, a phenomenon known as productivity paradox. The failure might relate to problems with the measurement techniques. This paper describes a measurement model, known as the PPP model (“Profitability = Productivity + Price Recovery”), that can fill the gap and show a link between IT investments, productivity, and profitability. The spreadsheet-based implementation of the PPP model, using multi-period data, generates performance trend charts of productivity, price recovery, and profitability. These performance charts provide a multi-period perspective to managers in identifying and understanding the impact of IT investments. This model is useful to managers considering heavy investments in IT as well as for managers interested in assessing their organizational performance and taking corrective actions in a timely manner.
An Analytical Model to Measure IS-Enabled Organizational Effectiveness
Authors: Tang Chun Meng , Marthandan Govindan
Published: September 2012

When business managers are considering whether to invest in an enterprise resource planning (ERP) system, they ask the question: “What are the returns on investment?” When the ERP system is implemented and in operation, business managers ask another question: “How successful is the system?” To answer these questions, clues can be found by examining organizational effectiveness improvements as a result of ERP system implementation. This paper suggests that being able to identify the dimensions of organizational effectiveness is enabled by ERP systems. Together with positive organizational effectiveness improvements, the business value of ERP systems can be demonstrated. To provide the evidence needed to support the notion, a confirmatory factor analysis (CFA) was conducted. Analyses reveal that the construct of IS-enabled organizational effectiveness can be modeled, at a higher-order abstraction level, as a third-order construct manifested by three second-order constructs and ten first-order constructs.
A Maturity Model of Strategic Information Systems Planning (SISP)
Authors: Pita Zijad , Cheong France , Corbitt Brian
Published: September 2012

Strategic Information Systems Planning (SISP) maturity model is conceptualized as a five-stage maturity model. To identify the maturity stage of SISP, a model for assessment of SISP is developed. The development of these models is based on the ‘Integral Engineering’ approach and a unique implementation of the Analytical Network Process theory (ANP). The SISP assessment model is structured as a multi-order system. High level constructs are presented in this paper. A new approach to SISP offers improving our understanding of the concept of SISP, and a means of structured evaluation and reformulation of SISP. The SISP assessment model can be used as an early warning diagnostic tool to draw attention to particular aspects of the SISP that need improvement or to justify the undertaking of SISP.
A Maturity Model of Strategic Information Systems Planning (SISP)
Authors: Pita Zijad , Cheong France , Corbitt Brian
Published: September 2012

In this paper Strategic Information Systems Planning (SISP) maturity models are empirically validated in Australian environment. A research instrument used to determine the degree of SISP maturity in Australian organisations is described. While empirical testing of a five-stage SISP model has only confirmed the existence of three levels of SISP maturity, statistical methods confirmed the adequacy of the establishment of the SISP assessment model as a third-order system. The study also opens the way for SISP thinking beyond the conventional approaches by introducing the Analytic Network Process and the Analytic Hierarchy Process methods to reduce complexity of SISP measurement in a natural and structural way. By using these methods, it was possible to obtain a single overall measure of SISP maturity, thus overcoming a problem of result synthesis measured by different scales.
Sustainable Competitive Advantage in E-Commerce and the Role of the Enterprise System
Authors: Schubert Petra , Williams Susan P. , Woelfle Ralf
Published: September 2012

Developing and sustaining a competitive advantage from the use of information technology is a topic of concern for information systems research. Mata et al. (1995) present a model that is founded on the resource-based view of the firm. The model is used to discuss factors that lead to competitive advantage in e-commerce companies. This paper explores factors that enable sustainable competitive advantages in B2C retailing. The analysis is based on a single in-depth case study of an Internet pioneer company (LeShop), which was observed by the authors since its inception more than 10 years ago. The research data stems from a series of interviews with managers at LeShop as well as two case studies about the company from two different points in time (2000 and 2009). LeShop is an online pioneer, which began selling groceries on the Internet in Switzerland in April 1998. After a turbulent few years, LeShop is now one of the few successful e-commerce suppliers in the supermarket segment worldwide. The discussion includes an analysis of further critical resources of the company from a resource-based view.
Is it Really so ‘Strategic’? Motivational Factors for Investing in Enterprise Systems
Authors: Lech Przemyslaw
Published: September 2012

This paper presents empirical research on motivational factors for investing in Enterprise Systems (ES), based on the survey conducted among project leaders. The results show that enterprises make investments in ES mostly to increase operational efficiency, provide managers with more accurate information and, which is interesting, to be able to continue the operations on the current level. Almost one third of examined enterprises indicated the replacement of an inefficient IT infrastructure with a new one enabling smooth operation of current business processes as the most important motivational factor for investments. The results of the research presented in this paper may help to understand the productivity paradox as they prove that many enterprises treat IT as a commodity rather than a strategic asset that generates significant business gains.
Knowledge Management for Strategic Alliances
Authors: Donate Mario J. , Guadamillas Fátima , Sánchez de Pablo Jesús D.
Published: September 2012

Managing organizational knowledge in alliances implies establishing the best possible strategic design to create, acquire, maintain, transfer, and apply organizational knowledge developed between the partners (or acquired from partners) in order to achieve competitive goals. In this paper, the role of knowledge management strategy (KMS) in strategic alliances is analyzed in a technology-intensive company. The importance of alliances for technological companies and the necessity of designing suitable KMSs in alliances –in terms of objectives and goals, knowledge management tools, and support systems– are explained first of all. Moreover, the analysis of a case study of KMS in the strategic alliances of a company currently developing different businesses in technological settings is developed by the authors. Finally, several conclusions are discussed, based on how the implementation aspects concerning KMS in strategic alliances have been managed and the way they have contributed to the attainment of the company’s objectives and goals.
The Competitive Advantages of a Holistic Approach to Supply Chain Management
Authors: Saban Kenneth
Published: September 2012

Supply chain performance is often equated with having the latest collaborative technology in place. However, current studies suggest that supply chain performance also requires human collaboration. To change conventional thinking, this paper proposes a holistic approach to supply chain management (SCM), clarifies the forces that facilitate human collaboration, and highlights the economics advantages of employing a holistic supply chain management approach.
Academic Strategies for Distance Education
Authors: Baporikar Neeta
Published: September 2012

Education all over the world is of paramount importance as it provides economies with opportunities for development and growth. Education is important for both – developed and developing economies – for the former to maintain their lead position and for the latter to ensure decent livelihood and utilization of natural resources. In such a situation, education needs to continuously upgrade itself to meet the ever changing needs of the economy, society and mankind. Hence, understanding education reviewing the developments, methods and standards are important if all stakeholders have to be satisfied. With globalization of education and the bent towards professional courses, Distance Education (DE) is established and is being more and more sought after. However, adopting academic strategies which will have mutual recognition across the world ensure holistic development and aid to maintain standards and quality of DE, is crucial need of the hour. The proposed paper aims to address these issues.
An Exploratory Study of Infrastructure Barriers and the Role of Semantic Data Exchange Technologies in the Provisioning of Business Intelligence Services
Authors: Mendoza Rubén A.
Published: September 2012

Business Intelligence (BI) has been a top technology development concern for high-ranking IT executives over the past decade. The objective of BI is to use data analysis as a competitive weapon, deeply integrated into business processes. The ability of an organization to provide enterprise-level BI services depends heavily on its IT strategy, itself a function of existing technology investment. Previous research has described four IT architecture stages ranging from isolated applications to modular services, each with increasing complexity and service capabilities. Representatives from four companies were interviewed about the status of their BI activities, and the resulting data helps identify common barriers faced by these organizations in the provisioning of enterprise-level BI services. Interview results also describe the success of a limited-scope operational BI system by one of these firms, and the role of semantic data exchange technologies, primarily XML, in this system.
The Effect of Firewall Testing Types on Cloud Security Policies
Authors: Shebanow Annie , Perez Richard , Howard Caroline
Published: September 2012

An important aspect of security requirements is a firm understanding of the threats to systems so that specific defense mechanisms can be implemented. Globally scattered network systems and on-demand access to systems such as cloud computing require a high level of security, because the software and hardware of networks are integrated in vulnerable shared or outsourced environments. Hackers are relentless in finding new techniques to gain access to sensitive data. Securing infrastructures is a challenging task, but when researchers identify and investigate potential threats and create solutions, vulnerabilities may be reduced. The purpose of this paper is to explore how use, misuse, positive and negative, obstacle, and abuse testing cases of firewalls have broadened the security policies that mitigate or prevent threats in a cloud environment.
A New Model to Compute the Information Content of Concepts from Taxonomic Knowledge
Authors: Sánchez David , Batet Montserrat
Published: September 2012

The Information Content (IC) of a concept quantifies the amount of information it provides when appearing in a context. In the past, IC used to be computed as a function of concept appearance probabilities in corpora, but corpora-dependency and data sparseness hampered results. Recently, some other authors tried to overcome previous approaches, estimating IC from the knowledge modeled in an ontology. In this paper, the authors develop this idea, by proposing a new model to compute the IC of a concept exploiting the taxonomic knowledge modeled in an ontology. In comparison with related works, their proposal aims to better capture semantic evidences found in the ontology. To test the authors’ approach, they have applied it to well-known semantic similarity measures, which were evaluated using standard benchmarks. Results show that the use of the authors’ model produces, in most cases, more accurate similarity estimations than related works.
Adding Semantic Annotations into (Geospatial) RESTful Services
Authors: Saquicela Victor , Vilches-Blázquez Luis M. , Corcho Oscar
Published: September 2012

In this paper the authors present an approach for the semantic annotation of RESTful services in the geospatial domain. Their approach automates some stages of the annotation process, by using a combination of resources and services: a cross-domain knowledge base like DBpedia, two domain ontologies like GeoNames and the WGS84 vocabulary, and suggestion and synonym services. The authors’ approach has been successfully evaluated with a set of geospatial RESTful services obtained from ProgrammableWeb.com, where geospatial services account for a third of the total amount of services available in this registry.
Inhibitors of DNA Binding Proteins Restrict T Cell Potential by Repressing Notch1 Expression in Flt3-Negative Common Lymphoid Progenitors
Authors: Pereira de Sousa Ana , Berthault Claire , Granato Alessandra , Dias Sheila , Ramond Cyrille , Kee Barbara L. , Cumano Ana , Vieira Paulo
Published: September 2012

Lineage commitment is regulated during hematopoiesis, with stepwise loss of differentiation potential ultimately resulting in lineage commitment. In this study we describe a novel population of B/NK bipotent precursors among common lymphoid progenitors in the fetal liver and the bone marrow. The absence of T cell precursor potential, both in vivo and in vitro, is due to low Notch1 expression and secondary to inhibition of E2A activity by members of the inhibitor of DNA binding (Id) protein family. Our results demonstrate a new, Id protein-dependent, molecular mechanism of Notch1 repression, operative in both fetal and adult common lymphoid progenitors, where T cell potential is selectively inhibited without affecting either the B or NK programs. This study identifies Id proteins as negative regulators of T cell specification, before B and NK commitment, and provides important insights into the transcriptional networks orchestrating hematopoiesis.
Chronic Beryllium Disease, HLA-DPB1, and the DP Peptide Binding Groove
Authors: Silveira Lori J. , McCanlies Erin C. , Fingerlin Tasha E. , Van Dyke Michael V. , Mroz Margaret M. , Strand Matthew , Fontenot Andrew P. , Bowerman Natalie , Dabelea Dana M. , Schuler Christine R. , Weston Ainsley , Maier Lisa A.
Published: September 2012

Multiple epidemiologic studies demonstrate associations between chronic beryllium disease (CBD), beryllium sensitization (BeS), and HLA-DPB1 alleles with a glutamic acid residue at position 69 (E69). Results suggest that the less-frequent E69 variants (non-*0201/*0202 alleles) might be associated with greater risk of CBD. In this study, we sought to define specific E69-carrying alleles and their amino acid sequences in the DP peptide binding groove, as well as their relationship to CBD and BeS risk, using the largest case control study to date. We enrolled 502 BeS/CBD subjects and 653 beryllium-exposed controls from three beryllium industries who gave informed consent for participation. Non-Hispanic white cases and controls were frequency-matched by industry. HLA-DPB1 genotypes were determined using sequence-specific primer PCR. The E69 alleles were tested for association with disease individually and grouped by amino acid structure using logistic regression. The results show that CBD cases were more likely than controls to carry a non-*02 E69 allele than an *02 E69, with odds ratios (95% confidence interval) ranging from 3.1 (2.1–4.5) to 3.9 (2.6–5.9) (p < 0.0001). Polymorphic amino acids at positions 84 and 11 were associated with CBD: DD versus GG, 2.8 (1.8–4.6), p < 0.0001; GD versus GG, 2.1 (1.5–2.8), p < 0.0001; LL versus GG, 3.2 (1.8–5.6), p < 0.0001; GL versus GG, 2.8 (2.1–3.8), p < 0.0001. Similar results were found within the BeS group and CBD/BeS combined group. We conclude that the less frequent E69 alleles confer more risk for CBD than does *0201. Recent studies examining how the composition and structure of the binding pockets influence peptide binding in MHC genes, as well of studies showing the topology of the TCR to likely bind DPB1 preferentially, give plausible biological rationale for these findings.
Private Goods, Public Goods, and Common Pools with Homo Reciprocans
Authors: Cox James C.
Published: September 2012

Familiar inefficiencies arise with competing interests over private goods in Stackelberg and investment games. Private good experiments reveal whether reciprocity enhances cooperative outcomes. Familiar social dilemmas arise with voluntary provision of public goods and voluntary appropriation from common pools. Experiments with pairs of payoff‐equivalent provision and appropriation games reveal whether reciprocity is more or less effective in ameliorating under‐provision or over‐appropriation. Experiments with asymmetric provision and appropriation games also yield insight into the effects of the Indian caste system on inefficiency from social dilemmas. Experiments with three types of games, with a private good, public good or common pool, provide diagnostic tests of the homo reciprocans model.
Government Bias in Education, Schooling Attainment, and Long‐Run Growth
Authors: Basu Parantap , Bhattarai Keshab
Published: September 2012

A surprising cross‐country stylized fact is that higher public spending on education tends to lower the long‐run growth rate of per capita GDP and the returns to schooling. This is contrary to the conventional wisdom that education is a major driver of growth. In this article, we revisit this issue and try to understand these puzzling facts in terms of an endogenous growth model. Our cross‐country calibration of the growth model predicts that countries with a greater government involvement in education experience lower schooling efforts and lower growth.
Help and Factionalism in Politics and Organizations
Authors: Chan William , Man Priscilla
Published: September 2012

Whether in electoral politics or promotions within organizations, players often face the dilemma of whether to enter the contest or to assist other candidates. This article analyzes incentives in a rank‐order tournament when the winner has control over resources that he can distribute to his supporters. Some players may then be encouraged to help others in exchange for paybacks, resulting in factionalism, with leaders and supporters sorted by ability. The number and the size of factions depend on the reward structure of the contest and the distribution of abilities. These implications are corroborated by data on U.S. gubernatorial primary elections.
The Stability of Social Preferences in a Low‐Income Neighborhood
Authors: de Oliveira Angela C. M. , Eckel Catherine , Croson Rachel T. A.
Published: September 2012

We investigate whether social preferences are stable across contexts using a field population of low‐income Americans. We develop and demonstrate a simplified, visually‐based experimental methodology appropriate for this population. We show that choices in a laboratory public goods game predict giving in real donation experiments, as well as self‐reported donations and volunteering outside the lab. At the same time, choices vary systematically by individual characteristics and decision context. Thus, our results provide evidence both for an underlying stable social preference and for the role of context in influencing the expression of that preference.
The Effect of Homework on Exam Performance: Experimental Results from Principles of Economics
Authors: Trost Steve , Salehi-Isfahani Djavad
Published: September 2012

We assess the effect of the completion of online homework assignments on exam performance in “Principles of Economics” using a unique experimental method. For specific homework assignments we randomize students into two groups: those for whom the assignment is optional and those for whom it is required. This randomization, which affects incentives to complete the homework assignment for a particular topic, generates an instrument that helps identify the effect of homework completion on topic‐specific exam performance. Results of the instrumental variables analysis, as well as results of a variety of other analyses, indicate that the completion of the assigned homework is positively (if not always significantly) correlated with higher scores on the midterms but not on the final exam—indicating “decay” in the homework effect over the course of the semester.
Ranking U.S. Economics Programs by Faculty and Graduate Publications: An Update Using 1994–2009 Data
Authors: McPherson Michael A.
Published: September 2012

This article ranks academic institutions by pages published in top economics journals over the 1994–2001 and 2002–2009 periods. Because it uses a methodology similar to several earlier articles, this article permits a consideration of how institutions' ranks have changed over the past 35 years. I construct rankings based on publications by individuals affiliated with each institution, by faculty members in the economics departments at each institution, and by alumni of each doctoral program. With few exceptions, the positions of programs near the top of the rankings change little over time. However, much more dramatic changes in rank occur for lower‐ranked institutions.
The Economics Olympics: Ranking U.S. Economics Departments Based on Prizes, Medals, and Other Awards
Authors: Mixon Franklin G. , Upadhyaya Kamal P.
Published: September 2012

This study ranks the top 25 U.S. economics departments on the basis of four prestigious awards won/held by these departments' current faculty: the Nobel Prize in Economic Sciences, the John Bates Clark Medal, the American Economic Association's (AEA's) Distinguished Fellow Award, and the American Economic Association's Richard T. Ely Lecturer. Based on our methodology, the top economics department is affiliated with the University of Chicago. This distinction stems from its affiliation with six Nobel Prize winners, four Clark Medal winners, and two participants each in the AEA Distinguished Fellow and Richard T. Ely Lecturer categories.
Evaluación global subjetiva y escala de malnutrición-inflamación para valorar el estado nutricional de pacientes en diálisis peritoneal con hipoalbuminemia
Authors: Jiménez Jiménez Sagrario , Muela Ortega Francisca , Segura Torres Pilar , Borrego Utiel Francisco , Gil Cunquero José Manuel , Liébana Cañada Antonio
Published: September 2012

Los pacientes con insuficiencia renal crónica en diálisis peritoneal con frecuencia están mal nutridos o en riesgo de desnutrición, por sus especiales características y favorecido por múltiples factores, como otras patologías asociadas, diálisis inadecuada, estado inflamatorio, pérdida de nutrientes por el dializado, etc.
Se han descrito numerosos métodos para evaluar el estado nutricional, siendo las medidas antropométricas y determinaciones de laboratorio las más utilizadas, pero cuando las aplicamos a pacientes renales los resultados obtenidos son muy variables, además algunos de ellos plantean problemas a la hora de su aplicación, por las especiales características de los pacientes en diálisis.
Una forma de prevenir la malnutrición es identificar a aquellos pacientes en riesgo de desnutrición y evitar su deterioro progresivo. Nuestro objetivo, es evaluar el estado nutricional de los pacientes en diálisis peritoneal con hipoalbuminemia. Hemos seleccionado 21 pacientes con más de 3 meses en diálisis peritoneal y con tendencia a tener hipoalbuminemia < 3,6 g/dl. Hemos evaluado su estado nutricional mediante la escala de evaluación global subjetiva y escala de malnutrición-inflamación.
Hemos encontrado que la mayoría de los pacientes presentan bajo riesgo de malnutrición estimado tanto por la evaluación global subjetiva donde el 85,7% tienen bajo riesgo de malnutrición o estado de nutrición normal y por la escala de malnutrición-inflamación igualmente el 85% tienen un estado de nutrición normal. Por tanto, debemos utilizar la combinación de varios métodos para evaluar adecuadamente el estado nutricional e identificar aquellos con riesgo de malnutrición.
Relación entre la presión intrabdominal en diálisis peritoneal con las hernias y fugas
Authors: Blasco Cabañas Concepción , Ponz Clemente Esther , Betancourt Castellanos Loreley , Otero López Sol , Marquina Parra Mª Dolores , Grau Pueyo Carmen , Moya Mejía Mª Carmen
Published: September 2012

La presión intrabdominal normal es igual a la atmosférica (cero). En Diálisis Peritoneal con la introducción del líquido intraperitoneal, la presión intrabdominal aumenta. En varios estudios se aconseja que esta no supere los 16-20 cm. H2O.
Además de las posibles molestias abdominales, una presión intrabdominal elevada puede tener relación con los problemas de la pared abdominal, como hernias y fugas y tener implicaciones en el transporte peritoneal y el déficit de ultrafiltración.
Los objetivos del presente trabajo fueron: conocer los niveles de presión intrabdominal de los enfermos prevalentes en diálisis peritoneal, valorar los factores que influyen en los valores de esta presión y estudiar retrospectivamente la relación entre presión intrabdominal y desarrollo de hernias y fugas.
Realizamos un estudio transversal, observacional y retrospectivo de valoración de la presión intrabdominal en los enfermos prevalentes, estables, con más de tres meses en diálisis peritoneal.
La presión intrabdominal se midió mediante el método descrito por Durand: paciente en decúbito supino, con el volumen peritoneal diurno. La presión intrabdominal final es la media entre las mediciones realizadas durante la inspiración y la espiración, se expresa en cm. de H2O, y se especifica el volumen drenado. También se realizó una medida en sedestación y en bipedestación.
Se estudiaron 34 pacientes, 66% varones, edad media de 61.2±14 años, 3 con poliquistosis renal, un índice de comorbilidad de Charlson medio de 7,9, un índice de masa corporal medio de 27.4±4.2 y un tiempo medio en DP de 21±12 meses. El volumen medio diurno fue de 1796±385 mL y el nocturno de 2100±254 mL. Un 32% de los pacientes tenían antecedentes de cirugía abdominal y un 5% de hernias, reparadas antes del inicio de la diálisis peritoneal.
La media de presión intrabdominal en decúbito fue de 17.5±4.1 cm. de H2O, y un volumen medio por superficie corporal de 1141±253 ml/m2. Un 23.5 % tenían una presión intrabdominal mayor a 20 cm. de H2O. En sedestación la media fue de 28±5.5 cm. de H2O y en bipedestación de 43.7±5.3 cm. de H2O. Los enfermos con presión intrabdominal > 20 cm. H2O tenían más porcentaje de hernias (50% vs 12 %) y fugas pericatéter (37 % vs. 12 %).
Como principales conclusiones, podemos destacar que los niveles de presión intrabdominal de nuestros pacientes son algo más elevados que en otras series. A mayor edad, mayor comorbilidad y mayor índice de masa corporal, la presión intrabdominal es más elevada. Los enfermos con presión intrabdominal elevada presentaron más episodios de hernias y fugas.
Satisfacción del paciente en una Unidad de Diálisis. ¿Qué factores modulan la satisfacción del paciente en diálisis?
Authors: Pérez Domínguez Tais , Rodríguez Pérez Armando , Suárez Álamo Jesús , Rodríguez Castellano Leire , García Bello Miguel Ángel , Rodríguez Pérez José Carlos
Published: September 2012

Introducción. La enfermedad renal requiere una atención sanitaria prolongada, en la que se conjugan tanto la competencia profesional como otras habilidades tanto emocionales como psicosociales. En dichos procesos crónicos, el usuario se convierte en el "centro del sistema", necesitando profesionales capaces de atenderles de una manera multidisciplinar. En este contexto, las políticas sanitarias no pueden desarrollarse sin tener en cuenta la opinión del paciente que supondrá un valor añadido para la percepción de su salud o bienestar.
Objetivo. Conocer el grado de satisfacción de los pacientes con enfermedad renal crónica en hemodiálisis. En segundo lugar, conocer las variables que se asocian al aumento o disminución de la satisfacción de los pacientes en las unidades de diálisis.
Material y Método. Participaron en la investigación 187 pacientes. La media de edad fue de 66 años. Utilizamos el cuestionario SERVQHOS modificado.
Resultados. Los niveles de satisfacción fueron altos y similares a los de otras unidades en España. Los aspectos peor valorados por nuestros pacientes eran el "tiempo de espera", "el servicio de ambulancias" y la "calidad de la comida". Factores como la edad, el tiempo en diálisis, el sexo y el turno de diálisis (turno de mañana o de tarde) modulan las puntuaciones en el cuestionario.
Conclusiones. Identificar los factores que modulan la satisfacción es tan importante como evaluarla. Deben de tenerse en cuenta las variables inherentes del paciente, que están condicionando la satisfacción percibida.
Hemodiafiltración en línea pre-dilucional, frente a post-dilucional: estudio comparativo de eficacia dialítica y tolerancia hemodinámica
Authors: Menezo Viadero Raquel , García Martínez Mirian , Pelayo Alonso Raquel , Cobo Sánchez José Luis , Rojo Tordable Marina , Tovar Rincón Alicia , Olalla Antolín Violeta , Sáez de Buruaga Perea Mª Araceli , Cepa García Hortensia , Incera Setién Mª Elena , Pérez Garmilla Ana Isabel , Peiró Sampayo Salvadora , Higuera Roldan Mª del Carmen , Alonso Nates Rosa
Published: September 2012

La hemodiafiltración en línea es una técnica de diálisis que combina las ventajas de la hemodiálisis de alto flujo (transporte difusivo) y la hemofiltración (transporte convectivo).
Esta técnica permite varias alternativas según se incorpore el líquido de reinfusión: pre-dilucional (antes del dializador) y post-dilucional (después del dializador), presentando cada una de ellas ventajas e inconvenientes.
El objetivo de este estudio fue comparar distintos parámetros dialíticos y hemodinámicos entre los modos de hemodiafiltración pre y postdilucional.
Se realizó un estudio prospectivo transversal en una población en diálisis que ya se trataba con hemodiafiltración en línea, sometiéndose durante 4 semanas a cada una de las modalidades (pre y post-dilucional).
Se registraron los valores de: tensión arterial sistólica, diastólica y frecuencia cardiaca pre y post sesión, flujo de sangre, presión venosa, volumen de sangre dializado y volumen de sustitución.
La dosis de diálisis se midió mediante dialisancia iónica.
Se estudiaron 26 pacientes: 30% mujeres y 70% hombres, con una edad media de 61±13 años. El tiempo medio en tratamiento renal sustitutivo fue de 117±124,45 meses, tiempo medio en hemodiálisis fue de 50±54,38 meses.
Los parámetros hemodinámicos no han presentado diferencias significativas entre las dos modalidades estudiadas (pre y post-dilucional). Se obtiene un mayor valor de KT estadísticamente significativo en la técnica de hemodiafiltración post-dilucional precisando ésta un volumen de sustitución de la mitad, en comparación con la modalidad pre-dilucional.
Conclusiones: La técnica de hemodiafiltración en línea es bien tolerada en las dos modalidades de infusión.
Ante un mismo flujo de sangre, presión venosa y volumen de sangre dializado se consigue una mejor dosis de diálisis en el modo post-dilucional.
La hemodiafiltración post-dilucional parece ser una mejor alternativa respecto a la pre-dilucional en relación a los parámetros estudiados siempre que no se tenga en cuenta la problemática de los accesos vasculares. Con dicha técnica logramos mejores resultados de KT precisando la mitad de volumen de sustitución, con el consiguiente ahorro de agua ultrapura.
La hemodiafiltración pre-dilucional puede ser una alternativa para aquellos pacientes que no se consiga un flujo arterial alto.
¿Qué indicadores son considerados por enfermería para conseguir una diálisis perfecta en el paciente en hemodiafiltración en línea?
Authors: Fernández Martínez Ana Vanessa , Piñero Martínez Josefa , Arregui Arias Yanina Valeria , Pérez García Rosario , Moreno Vallejo Alicia , Rodríguez Martínez Francisco , Orenes Bernabé Francisco José , Mc Ginn Matthew John
Published: September 2012

Tanto las guías, como las indicaciones del Grupo de Gestión de Calidad de la Sociedad Española de Nefrología nos proponen una serie de indicadores para medir la calidad de la prestación de la hemodiálisis.
El objetivo del presente estudio fué, tras conocer cuales son los principales indicadores de una diálisis óptima para el personal de enfermería, evaluar objetivamente cada sesión de diálisis, en el convencimiento de que del conocimiento de los aciertos/fallos de cada sesión, obtendríamos propuestas de mejora de una forma más precoz que con los indicadores comúnmente utilizados.
Para ello, se realizó una encuesta entre el personal de enfermería (n=26) solicitándole que enumerara los 10 parámetros que le parecían fundamentales para una sesión de diálisis óptima. Los 10 ítems más nombrados se utilizaron para elaborar la hoja de recogida de datos, con respuestas si/no.
En cada paciente (n=160) se analizaron 3 sesiones consecutivas (n=480 sesiones), con la misma pauta de tratamiento.
El enfermero que realiza las sesiones desconoce que sesiones se van a evaluar, así como la identidad de un segundo enfermero evaluador, que será el encargado de marcar si/no en cada uno de los ítems. Por cada objetivo conseguido se otorga 1 punto. La puntuación máxima por cada paciente es de 30 puntos (10 por sesión), excepto en los portadores de catéter tunelizado, en los que es de 27 puntos (9 por sesión), al no ser procedente valorar la hemostasia.
Hemos obtenido como resultado que el 41,3% de las sesiones realizadas obtuvieron la máxima puntuación (42,1% con Fístula arteriovenosa y 35,1% con catéter tunelizado, p=0,043). La puntuación porcentual obtenida fue 88,7 ± 11,9%, porcentaje significativamente mayor con FAV que con catéter (89,9 ± 9,9 versus 79,7 ± 19,4, p
La unidad de diálisis, ¿un entorno accesible?
Authors: López González Antonio , Díaz Rodríguez Lorena , Ornosa Agra Mª del Carmen
Published: September 2012

Uno de los efectos producidos por los notables cambios demográficos experimentados en las últimas décadas en nuestro país es el aumento de las personas con discapacidad. Ante esta situación, los gobiernos han ido implantando políticas sociales y sanitarias con la finalidad de garantizar el derecho a la igualdad. En este aspecto cobra especial relevancia, como elemento de calidad de vida y de integración, el derecho a la accesibilidad universal entendida esta como "la condición que deben cumplir los entornos, procesos, bienes, productos y servicios, así como los objetos o instrumentos, herramientas y dispositivos, para ser comprensibles, utilizables y practicables por todas las personas en condiciones de seguridad y comodidad y de la forma más autónoma y natural posible".
El objetivo de este estudio es analizar la situación de accesibilidad de las instalaciones de la Unidad de Diálisis del USP Hospital Santa Teresa, proponer tipos de mejora para la adaptación del entorno, conocer la percepción del profesional acerca de la accesibilidad de la Unidad y analizar el grado de conocimiento e implicación relacionado con los derechos de las personas con discapacidad y adultos mayores.
Estandarización de cuidados del síndrome metabólico en diálisis peritoneal
Authors: Cirera Segura Francisco , Ruiz Montes Myriam , Rosales Sánchez Verónica , Martín Espejo Jesús Lucas
Published: September 2012

Introducción. Detectamos una gran prevalencia de factores de riesgo cardiovascular en los pacientes incidentes y prevalentes en diálisis peritoneal. Objetivo. Elaborar un plan de cuidados estandarizado para pacientes en diálisis peritoneal que diera respuesta a los problemas derivados del síndrome metabólico.
Material y Método. La población objeto fueron los pacientes en diálisis peritoneal.
Se realizó una valoración de las necesidades según Marjory Gordon, y se utilizaron las taxonomías NANDA, NIC y NOC para establecer los diagnósticos, intervenciones y criterios de resultados más frecuentes.
Resultados. Los diagnósticos más prevalentes fueron: Conocimientos deficientes, Manejo inefectivo del régimen terapéutico, Desequilibrio nutricional por exceso y Deterioro de la movilidad física.
Se elaboraron las intervenciones a realizar en la consulta de Enfermería, así como los criterios de resultados esperados.
Las intervenciones se basaron en la educación del paciente sobre la modificación del estilo de vida, manejo adecuado de alimentación, realización de ejercicio físico adecuado a su edad, y en los aspectos relativos a la patología de base y tratamiento, como administración y manejo de los fármacos y líquidos de diálisis peritoneal.
Conclusión. Hemos estandarizado mediante un plan de cuidados, la atención a los problemas de salud derivados del síndrome metabólico, en los pacientes en programa de diálisis peritoneal.
GEM-AQ/EC, an on-line global multi-scale chemical weather modelling system: model development and evaluation of global aerosol climatology
Authors: Gong S. L. , Lavoué D. , Zhao T. L. , Huang P. , Kaminski J. W.
Published: September 2012

Abstract. A global air quality modeling system GEM-AQ/EC was developed by implementing tropospheric chemistry and aerosol processes on-line into the Global Environmental Multiscale weather prediction model – GEM. Due to the multi-scale features of the GEM, the integrated model, GEM-AQ/EC, is able to investigate chemical weather at scales from global to urban domains. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module CAM (The Canadian Aerosol Module) with 5 aerosols types: sulphate, black carbon, organic carbon, sea-salt and soil dust. Monthly emission inventories of black carbon and organic carbon from boreal and temperate vegetation fires were assembled using the most reliable areas burned datasets by countries, from statistical databases and derived from remote sensing products of 1995–2004. The model was run for ten years from from 1995–2004 with re-analyzed meteorology on a global uniform 1° × 1° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. The simulating results were compared with various observations including surface network around the globe and satellite data. Regional features of global aerosols are reasonably captured including emission, surface concentrations and aerosol optical depth. For various types of aerosols, satisfactory correlations were achieved between modeled and observed with some degree of systematic bias possibly due to large uncertainties in the emissions used in this study. A global distribution of natural aerosol contributions to the total aerosols is obtained and compared with observations.
Comparison of methods for evaluation of wood smoke and estimation of UK ambient concentrations
Authors: Harrison R. M. , Beddows D. C. S. , Hu L. , Yin J.
Published: September 2012

Abstract. Airborne concentrations of the wood smoke tracers, levoglucosan and fine potassium have been measured at urban and rural sites in the United Kingdom alongside measurements with a multi-wavelength aethalometer. The UK sites, and especially those in cities, show low ratios of levoglucosan to potassium in comparison to the majority of published data. It is concluded that there may be two distinct source types, one from wood stoves and fireplaces with a high organic carbon content, best represented by levoglucosan, the other from larger, modern appliances with a very high burn-out efficiency, best represented by potassium. Based upon levoglucosan concentrations and a conversion factor of 11.2 from levoglucosan to wood smoke mass, average concentrations of wood smoke including winter and summer sampling periods are 0.23 μg m−3 in Birmingham and 0.33 μg m−3 in London, well below concentrations typical of other northern European urban areas. There may be a further contribution from sources of potassium-rich emissions amounting to an estimated 0.08 μg m−3 in Birmingham and 0.30 μg m−3 in London. Concentrations were highly correlated between two London sites separated by 4 km suggesting that a regional source is responsible. Data from the aethalometer are either supportive of these conclusions or suggest higher concentrations, depending upon the way in which the data are analysed.
An empirical model of global climate – Part 2: Implications for future temperature
Authors: Mascioli N. R. , Canty T. , Salawitch R. J.
Published: September 2012

Abstract. IPCC (2007) has shown that atmosphere-ocean general circulation models (GCMs) from various research centers simulate the rise in global mean surface temperature over the past century rather well, yet provide divergent estimates of temperature for the upcoming decades. We use an empirical model of global climate based on a multiple linear regression (MLR) analysis of the past global surface temperature anomalies (ΔT) to explore why GCMs might provide divergent estimates of future temperature. Our focus is on the interplay of three factors: net anthropogenic aerosol radiative forcing (NAA RF), climate feedback (water vapor, clouds, surface albedo) in response to greenhouse gas radiative forcing (GHG RF), and ocean heat export (OHE). Our model is predicated on two key assumptions: whatever climate feedback is needed to account for past temperature rise will persist into the future and whatever fraction of anthropogenic RF (GHG RF + NAA RF) is exported to the oceans to match the observed rise in ocean heat content will also persist. Even with these assumptions, modeled future ΔT mimics the behavior of GCMs because the ~110 record of global surface temperature can not distinguish between two possibilities. If anthropogenic aerosols presently exert small cooling on global climate, feedback must be weak and the future rise in global average surface temperature in 2053, the time CO2 is projected to double according to RCP 8.5, could be moderate. If aerosols presently exert large cooling of global climate, feedback must be large and future ΔT when CO2 doubles could be substantial. Reduced uncertainty for climate projection requires observationally based constraints that can narrow the uncertainties that presently exist for net anthropogenic aerosol radiative forcing as well as the totality of feedbacks that occur in response to a GHG RF perturbation. GCMs are often compared by evaluating the equilibrium response to a doubling of CO2, termed climate sensitivity. In our model framework, ΔT at the time CO2 doubles is nearly independent of OHE, because climate feedback must be adjusted to properly simulate observed temperature. Our simulations show that if a small fraction of anthropogenic RF is exported to the ocean, equilibrium climate sensitivity closely represents the modeled ΔT at the time CO2 doubles. Conversely, if this fraction is large, ΔT when CO2 doubles is much less than the equilibrium climate sensitivity (i.e. the model is now far from equilibrium). Similar behavior likely occurs within GCMs. We therefore suggest the dependence of climate sensitivity on OHE be factored into analyses that use this metric to compare and evaluate GCMs.
Formulation and test of an ice aggregation scheme for two-moment bulk microphysics schemes
Authors: Kienast-Sjögren E. , Spichtinger P. , Gierens K.
Published: September 2012

Abstract. A simple formulation of aggregation for 2-moment bulk microphysical models is derived. The solution involves the evaluation of a double integral of the collection kernel weighted with the crystal size (or mass) distribution. This quantity is to be inserted into the differential equation for the crystal number concentration which has classical form. The double integrals are evaluated numerically for log-normal size distributions over a large range of geometric mean masses. A polynomial fit of the results is given that yields good accuracy. Various tests of the new parameterization are described: aggregation as stand-alone process, in a box-model, and in 2-D simulations of a cirrostratus cloud. These tests suggest that aggregation can become important for warm cirrus, leading even to higher and longer-lasting in-cloud supersaturation. Cold cirrus clouds are hardly affected by aggregation. The collection efficiency is taken from a parameterization that assumes a dependence on temperature, a situation that might be improved when reliable measurements from cloud chambers suggests the necessary constraints for the choice of this parameter.
Jena Reference Air Set (JRAS): a multi-point scale anchor for isotope measurements of CO2 in air
Authors: Wendeberg M. , Richter J. M. , Rothe M. , Brand W. A.
Published: September 2012

Abstract. The need for a unifying scale anchor for isotopes of CO2 in air was brought to light at the WMO CO2 Experts Meeting in Tokyo 2001. During discussions about persistent discrepancies in isotope measurements between the worlds leading laboratories it was concluded that a unifying scale anchor for VPDB of CO2 in air was desperately needed. Now, 10 yr later, the 2011 CO2-Experts-Meeting in Wellington has decided that the Jena Reference Air Set or JRAS is recommended as official scale anchor for isotope measurements of CO2 in air. The JRAS gases consist of reference CO2 mixed into CO2 free air. To safeguard both stability and longevity of the CO2, it is directly generated from two solid reference calcites. That the reference CO2 is supplied in air is unique to JRAS. This is made to ensure that any measurement bias arising from the extraction procedure is eliminated. As every lab has its own procedure for extracting the CO2 this is of paramount importance if the local scales are to be unified. For a period of four years, JRAS has been evaluated through the IMECC program, which made it possible to distribute sets of JRAS gases to 11 laboratories worldwide. A summary of the results is reported here along with a description of the production and maintenance of the JRAS scale anchors.
HDO/H2O ratio retrievals from GOSAT
Authors: Boesch H. , Deutscher N. M. , Warneke T. , Byckling K. , Cogan A. J. , Griffith D. W. T. , Notholt J. , Parker R. J. , Wang Z.
Published: September 2012

Abstract. We report a new shortwave infrared (SWIR) retrieval of the column-averaged HDO/H2O ratio from the Japanese Greenhouse Gases Observing SATellite (GOSAT). From synthetic simulation studies, we have estimated that the inferred δD values will typically have random errors between 20‰ (desert surface and 30° solar zenith angle) and 120‰ (conifer surface and 60° solar zenith angle). We find that the retrieval will have a small, but significant sensitivity to the presence of cirrus clouds, the HDO a priori profile shape and atmospheric temperature, which has the potential for introducing some regional-scale biases in the retrieval. From comparisons to ground-based column observations from the Total Carbon Column Observing Network (TCCON) we find differences between δD from GOSAT and TCCON of around −30‰ for northern-hemispheric sites which increase up to −70‰ for Australian sites. The bias for the Australian sites significantly reduces when decreasing the spatial co-location criteria, which shows that spatial averaging contributes to the observed differences over Australia. The GOSAT retrievals allow mapping the global distribution of δD and its variations with season and we find in our global GOSAT retrievals the expected strong latitudinal gradients with significant enhancements over the tropics. The comparisons to the ground-based TCCON network and the results of the global retrieval are very encouraging and they show that δD retrieved from GOSAT should be a useful product that can be used to complement datasets from thermal-infrared sounder and ground-based networks and to extend the δD dataset from SWIR retrievals established from the recently ended SCIAMACHY mission.