bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolitengehalte und Enzymaktivitäten in Geweben des Schweines
Authors: Reichl J. R. , Jansen Rosemarie
Published: February 2011

Es wurde eine multiple Regressionsanalyse mit 36 Tieren aus Experimenten, die in den ersten zwei Mitteilungen beschrieben wurden, für die Beziehung zwischen einzelnen Metaboliten‐gehalten (Y) in Leber (L) und Fettgewebe (F) zur Aufnahme von Rohprotein (X1), Umsetz‐barer Energie (X2) und zum Metabolischen Körpergewicht W0,75 (X3) durchgeführt. Diese Regressionskoeffizienten sind in den Tabellen 2 und 3 angegeben und mit diesen Koeffizien‐ten berechnete Metabolitengehalte als Mittelwerte entsprechend den Tiergruppen A, B, C, D aus dem ersten und L, X aus dem zweiten Experiment mit der (Curve Nr. 2 in den Abbildungen dargestellt. Fast alle angegebenen multiplen Korrelationskoeffizienten sind stati‐stisch signifikant, mit Ausnahme von PEP in der Leber und AGP und CIT im Fettgewebe.

Für die 20 Tiere aus dem ersten Experiment wurde noch die Beziehung der Metaboliten‐gehalte (Y) zu der täglichen Aufnahme an verdaulichem Rohprotein (X1), Verdaulicher Energie (X2) und W0,75 (X3), oder zu täglichem Proteinzuwachs (X1), täglichem Fettzu‐waehs (X2) und W0,75(X3) analysiert. Die zuerst genannte Beziehung ist mit Hilfe der Kurve Nr. 4 dargestellt worden und die zuletzt genannte Beziehung mit Hilfe der Kurve Nr. 3.

Kurve Nr. 1 in den Abbildungen entspricht den experimentell bestimmten Metabolitenge‐halten, die in den ersten zwei Mitteilungen tabelliert wurden.

Es konnten folgende Einflüsse der Aufnahme von Rohnährstoffen auf die Metaboliten‐gehalte in der Leber und im Fettgewebe festgestellt werden, wobei die Reihenfolge der Metabo‐liten von einem mehr einseitigen Einfluß eines Faktors zu einem mehr kombinierten Einfluß beider Faktoren dargestellt wurde: In der Leber zeigte die Rohproteinaufnahme einen posi‐tiven Einfluß auf die Gehalte von AGP, ACCO, LACT, MAL und CIT und einen negativen Einfluß auf die Gehalte von ASP, GLUT, 2‐PG und PEP; die Aufnahme der Umsetzbaren Energie zeigte einen positiven Einfluß auf die Gehalte von PYR, ACAC, GLUC und ASPN und einen negativen Einfluß auf die Gehalte von BHBA und AKG. In dem Fettgewebe hatte die Rohproteinaufnahme einen positiven Einfluß auf die Gehalte von CIT, AGP, ACAC und ACCO und einen negativen Einfluß auf die Gehalte von AKG, ASP, GLUT und ASPN; die Aufnahme der Umsetzbaren Energie zeigte einen positiven Einfluß auf die Gehalte von PEP und 2‐PG und einen negativen Einfluß auf die Gehalte von BHBA, GLUC, PYR, MAL und LACT.

An Hand der Beziehung von Metaboliten zur Aufnahme an Rohprotein, Umsetzbarer Energie und zum Metabolischen Körpergewicht konnten Verbesserungen der multiplen Korrelationskoeffizienten demonstriert werden (Tabelle 4 und 5). Bei einigen Metaboliten wurden diese Koeffizienten durch Dividieren der Metabolitengehalte durch W0,75, bei ande‐ren Metaboliten durch Multiplizieren dieser mit dem Gesamtgewicht von Leber oder Kör‐perfett verbessert.

Die in dieser Veröffentlichung nicht angegebenen Regressionskoeffizienten können auf Anfrage zugeschickt werden.
Zur Eiweißverdauung bei Wiederkäuern im Hinblick auf die faktorielle Berechnung des Eiweißbedarfes
Authors: Kaufmann W.
Published: February 2011

Es wird mit Hilfe einer Infusionstechnik in den Labmagen der Einfluß der bakteriellen Fermentation im Enddarm auf die Proteinverdaulichkeit gemessen. Dabei ergibt sich die wahre Verdaulichkeit bei Ausschaltung dieses Einflusses. Die Meßergebnisse für eine Reihe von Proteinen zeigen Werte für die wahre Verdaulichkeit von 90–95%.

Unter Benutzung der “standardisierten scheinbaren Verdaulichkeit” (13% Protein, 550–600 StE) läßt sich der endogene N‐Anteil errechnen (26 g Protein je kg Tr.S.). Die neuen Werte werden zur faktoriellen Berechnung des Rohproteinbedarfs der Milchkuh be‐nutzt. Die Ergebnisse sind tabellarisch und graphisch dargestellt und die Wirkung von ge‐schütaztem Protein auf den Bedarf ist ebenfalls angeführt.
Effects of cold exposure on responses of plasma insulin, glucagon, and metabolites in heifers
Authors: Itoh F. , Obara Y. , Fuse H. , Rose M. T. , Osaka I. , Takahashi H.
Published: February 2011

Effects of cold exposure on plasma insulin, glucagon, and metabolite responses following an injection of nutrients were investigated in heifers. Four heifers, fed hay and a commercial concentrate, were exposed to thermoneutral (20°C) and cold (0°C) environments. Glucose, arginine and butyrate (each injection at 0.625 mmol/kg), and insulin (0.2U/kg) were injected intravenously, and then blood was taken at regular intervals through jugular vein catheters. Insulin secretion in response to glucose, arginine and butyrate injection was not affected by cold exposure compared with several reports that noted an inhibited insulin response in cold exposed sheep. The glucagon response (AUC; response area) to the arginine injection was slightly increased during cold exposure. Plasma glucose decreased to below basal levels after recovery from hyperglycaemia following glucose injection in the cold environment. The increase in plasma insulin (AUC) after exogenous insulin injection tended to be smaller during cold exposure, and peak insulin value was also inhibited significantly during cold exposure. It is concluded that in heifers, cold stress does not influence insulin secretion in response to secretagogues, however, sensitivity to insulin action following exogenous glucose injection and insulin clearance tended to be enhanced by cold stress.

Der Einfluß eines Kältestress auf die Konzentrationen von Insulin, Glucagon und andere Stoffwechselparameter im Plasma von Rindern

Vier Rinder, die Heu und Kommerzielles kraftfutter erhielten, wurden bei einer thermoneutralen Temperatur (20°C) und bei Kälte (0°C) gehalten. Zugleich erhielten die Tiere Injektionen (0,635 mmol/kg) von Glucose, Arginin und Butyrat, zusätzlich 0,2 U/kg Insulin intravenös verabreicht. In regelmäiigen Intervallen wurde den Rindern Blut durch Venenverweilkatheter entnommen. Die Insulin‐Sekretion wurde durch die Injektion von Arginin und Butyrat durch einen Kältestress nicht verändert. Dies steht im Gegensatz zu Ergebnissen, die bei Schafen gefunden wurden. Der Glucagon‐Respons (AUC; Respons‐Areal) war nach einer Arginin‐Injektion bei Kältestress leicht erhöht. Die Plasma‐Glucosewerte sanken bei Kältebehandlung unter die Basalwerte nach einer Insulininjektion und der damit verbundenen Hyperglykämie. Der Anstieg des Plasma‐Insulins (AUC) nach einer exogenen Insulin‐Injektion scheint bei Kältestress geringer zu sein. Die höchste Insulin‐Konzentration liegt bei Kältestress ebenfalls niedriger als bei thermoneutraler Haltung der Rinder. Daraus ist zu schließen, daß ein Kältestress bei Rindern die Insulin‐Sekretion in Abhängigkeit der Injektion von Glucose, Arginin und Butyrat nicht beeinflußt, die Insulin‐Wirkung nach der exogenen Injektion von Insulin und die Insulin‐Clearence bei Kältestress aber verstärkt.
Self‐regulation through Goal Setting*
Authors: Koch Alexander K. , Nafziger Julia
Published: February 2011

Goals are an important motivator. But little is known about why and how people set them. We address this issue in a model based on two stylized facts. First, goals serve as reference points for performance. Second, present‐biased preferences create self‐control problems. We show the power and limits of self‐regulation through goals. Goals increase an individual's motivation—but only up to a certain point. Furthermore, they are painful self‐disciplining devices. Thus, greater self‐control problems may result in tougher goals; but for a severe present bias goals either lack a motivating force, or are too painful to be accepted.
A novel technique for chitosan microparticle preparation using a water/silicone emulsion: green tea model
Authors: Wisuitiprot W. , Somsiri A. , Ingkaninan K. , Waranuch N.
Published: February 2011

Synopsis

Many effective methods such as spray drying, coacervation, ionic gelation, solvent evaporation and sieving have been suggested for entrapping bioactive compounds into micro‐ or nanoparticles. However, those methods still have some limitations owing to high temperature requirement, difficulty in particle harvesting or low entrapment for uncharged molecules. In this study, a novel chitosan microparticle preparation method was developed using water‐in‐silicone emulsion technique with green tea extract as a model active compound. Chitosan microparticles of diameter <5 μm were obtained from 2% chitosan solution with tripolyphosphate (TPP) solution as the hardening agent. The size and properties of the particles appeared to depend on several parameters such as TPP, emulsifier concentrations and pH. High concentration of emulsifier led to low encapsulation and particle aggregation. Entrapment efficiency of chitosan microparticles was improved with lower pH of the tripolyphosphate solution [59.94 ± 3.97 of epigallocatechin gallate (EGCG)] while slowing release of catechins. Epigallocatechin and epicatechin were released almost completely within 2 h under acidic condition whereas EGCG and epicatechin gallate were slowly released. In neutral condition, release of catechins depended on their molecular stabilities. The stabilities of catechins loaded in chitosan microparticles were varied under various temperatures. The degradation of tea catechins increased with temperature. However, the degradation of tea catechins loaded in chitosan microparticles was less than that of free catechins. Thus, the new technique for preparing chitosan microparticles containing heat‐sensitive water soluble green tea extract was successfully developed. The technique is suitable for micro‐encapsulation of hydrophilic compounds into chitosan microparticles with the ease of harvesting technique.
Systemic lupus erythematosus induced by interferon β1 therapy in a patient with multiple sclerosis
Authors: Bahri Dalila Mrabet , Khiari Hela , Essouri Asma , Laadhar Lilia , Zaraa Ines , Mrabet Amel , Meddeb Nihel , Sellami Slaheddine
Published: February 2011

Drug‐induced lupus erythematosus is defined as a lupus‐like syndrome temporally related to a drug exposure. We report a 34‐year‐old woman with multiple sclerosis who developed, while being treated with interferon β‐1a, myalgia and associated with wrist synovitis. Clinical and immunologic investigations were in favor of systemic lupus erythematosus. Interferon therapy was maintained. Under corticosteroids and antipaludeen treatment, the patient did not develop any other lupic manifestations.
Biotransformation of 6‐thioguanine in inflammatory bowel disease patients: a comparison of oral and intravenous administration of 6‐thioguanine
Authors: Jharap B , de Boer NKH , Vos RM , Smid K , Zwiers A , Peters GJ , Mulder CJJ , Wilhelm AJ , van Bodegraven AA
Published: February 2011

BACKGROUND AND PURPOSE

Although 6‐mercaptopurine and azathioprine are effective treatments in inflammatory bowel disease (IBD), many patients discontinue treatment because of side effects. 6‐Thioguanine (6‐TG) may be an alternative rescue therapy in these intolerant patients but the pharmacokinetics of 6‐TG are not fully described. Here we have measured the pharmacokinetics of the biotransformation of 6‐TG into the pharmacologically active metabolites, 6‐thioguanine nucleotides (6‐TGN), in IBD patients.

EXPERIMENTAL APPROACH

In 12 patients with IBD, levels of 6‐TGN and activities of thiopurine S‐methyltransferase, xanthine oxidase and hypoxanthine guanine‐phosphoribosyl‐transferase were measured in a two‐stage (i.v. and p.o. administration of 0.3 mg·kg−1 6‐TG), prospective study. Median exposure of 6‐TGN in red blood cells (RBC) was expressed as the ratio of the area under the curve (AUC) per mg 6‐TG after i.v. dosing and that after p.o. dosing.

KEY RESULTS

The median AUC per mg 6‐TG was 1068 (p.o.) and 7184 (i.v.) pmol·h (8 × 108 RBC)−1. Median exposure of 6‐TGN in RBC was 15% (9–28). Hypoxanthine guanine‐phosphoribosyl‐transferase activity correlated with peak 6‐TGN and with AUC per mg (r= 0.7, P= 0.02 and r= 0.6, P= 0.03 respectively). Thiopurine S‐methyltransferase activity was inversely related to AUC per mg (r=−0.8, P= 0.001), whereas that of xanthine oxidase was correlated with a lower peak 6‐TGN (r=−0.7, P= 0.02).

CONCLUSIONS AND IMPLICATIONS

The great variability of the AUC per mg for 6‐TG observed after p.o. and i.v. administration of 6‐TG, was partly explained by variability in activities of metabolizing enzymes. Exposure of 6‐TGN was low in all patients.
Hepatitis C virus and kidney: a strong association with different clinical aspects
Authors: Pipili Chrisoula , Ilonidis George , Cholongitas Evangelos
Published: February 2011

The most frequent kidney disease associated with chronic hepatitis C virus (HCV) infection is membranoproliferative glomerulonephritis in patients with type II mixed cryoglobulinaemia. The principal clinical manifestations of glomerular disease in HCV‐infected patients are the presence of proteinuria and haematuria with or without impaired kidney function. Pharmaceutical regimens vary because the main pathogenesis of renal dysfunction often mediated by cryoglobulins has not been fully elucidated. HCV infection remains common in patients on renal replacement therapy and has an adverse impact on their survival. Safe and effective pharmaceutical regimens have not been yet established and nosocomial spread within dialysis units continues to occur. Monotherapy with interferon for HCV infection is probably more effective in dialysis than in non‐uraemic patients, while experience with ribavirin is limited because of its adverse haemolytic effect. Based on shortage of cadaver kidneys and the fact that HCV renal transplant recipients have better survival than stay on maintenance haemodialysis or at list for transplantation, health organization proposed the use of cadaver kidneys from anti‐HCV‐positive donors, bringing up concerns and conflicting views. This present review describes the main renal manifestations of HCV infection, the epidemiological and clinical characteristics of chronic kidney disease population and comments on the limitations and shortcomings of current therapeutical regiments.
Cherry Picking in ESRD: An Ethical Challenge in the Era of Pay for Performance
Authors: Clint Parker J.
Published: February 2011

In poorly designed pay‐for‐performance schemes in which case mix adjustments are not adequate, self‐interest could lead nephrologists toward cherry picking dialysis patients. Cherry picking, however, is morally problematic. First, it may manifest itself as a subtle form of covert rationing which threatens to undermine patient trust. Second, it involves shifting the burden of caring for sicker (and less financially attractive) patients to other nephrologists and dialysis units that do not practice cherry picking, creating injustices in the health care system. Finally, it treats patients as mere means through which nephrologists achieve reimbursement instead of as persons possessing dignity and deserving of respect.
Cornerstones of Public Health Nursing
Authors: Keller Linda Olson , Strohschein Susan , Schaffer Marjorie A.
Published: February 2011

ABSTRACT
The “Cornerstones of Public Health Nursing” describe the values and beliefs that underlie the practice of Public Health Nursing, which is a synthesis of public health and nursing. The impetus for the development of the Cornerstone framework originated from the need to advocate for public health nursing programs, positions, and funding. Grounded in practice, their development engaged stakeholders from the public health nursing community at every phase. The Cornerstone framework has been used over the past decade by educators to teach public health nursing and by administrators in state and local health departments for orientation and continuing education. The Cornerstones have been nationally and internationally disseminated. This paper describes the development and dissemination of the Cornerstones framework by public health nurses in Minnesota and features exemplars from practice.
The Impact of Web‐delivered Education on Preceptor Role Self‐Efficacy and Knowledge in Public Health Nurses
Authors: Larsen Rachelle , Zahner Susan J.
Published: February 2011

ABSTRACT
Objective: Preceptors are an essential component in preparing student nurses to become practicing public health nurses. Preparation for the preceptor role is important for achieving a quality learning experience for students. This study was conducted to explore the relationship between completion of a Web‐delivered preceptor education program and both knowledge of the preceptor role and self‐efficacy to perform in the preceptor role.

Design and Sample: This study used a pretest‐posttest, quasi‐experimental design. The participants were experienced public health nurses (n=31) working in one state in the United States.

Measures: Pretest and posttest Web‐delivered survey using the preceptor self‐efficacy questionnaire and an instrument assessing knowledge gain.

Intervention: A Web‐delivered preceptor education program tailored for public health nurses.

Results: The program was associated with improved self‐efficacy scores at both the immediate and the 3‐month posttest, and with increased knowledge of the preceptor role evident at the immediate posttest only. Self‐efficacy scores were independent of knowledge scores. Preceptor age was not correlated with self‐efficacy or knowledge scores. Nurses with higher levels of education demonstrated higher self‐efficacy scores in all 3 measurements.

Conclusions: Web‐delivered continuing education targeted to public health nurse preceptors is an effective method to increase confidence and knowledge for the preceptor role.
Changes in Heart Rate Variability Associated With Acute Alcohol Consumption: Current Knowledge and Implications for Practice and Research
Authors: Romanowicz Magdalena , Schmidt John E. , Bostwick John M. , Mrazek David A. , Karpyak Victor M.
Published: February 2011

Alcohol consumption is associated with a broad array of physiologic and behavioral effects including changes in heart rate. However, the physiologic mechanisms of alcohol effects and the reasons for individual differences in the cardiac response remain unknown. Measuring changes in resting heart rate (measured as beats/min) has not been found to be as sensitive to alcohol’s effects as changes in heart rate variability (HRV). HRV is defined as fluctuations in interbeat interval length which reflect the heart’s response to extracardiac factors that affect heart rate. HRV allows simultaneous assessment of both sympathetic and parasympathetic activity and the interplay between them. Increased HRV has been associated with exercise and aerobic fitness, while decreased HRV has been associated with aging, chronic stress, and a wide variety of medical and psychiatric disorders. Decreased HRV has predictive value for mortality in general population samples and patients with myocardial infarction and used as an indicator of altered autonomic function. A significant inverse correlation was found between HRV and both the severity of depression and the duration of the depressive episode. HRV analysis provides insights into mechanisms of autonomic regulation and is extensively used to clarify relationships between depression and cardiovascular disease. This article will review the methodology of HRV measurements and contemporary knowledge about effects of acute alcohol consumption on HRV. Potential implications of this research include HRV response to alcohol that could serve as a marker for susceptibility to alcoholism. At present however there is almost no research data supporting this hypothesis.
What Is and What Can Be: How a Liminal Position Can Change Learning and Teaching in Higher Education
Authors: Cook‐Sather Alison , Alter Zanny
Published: February 2011

In this article we analyze what happens when undergraduate students are positioned as pedagogical consultants in a faculty development program. Drawing on their spoken and written perspectives, and using the classical anthropological concept of “liminality,” we illustrate how these student consultants revise their relationships with their teachers and their responsibilities within their learning. These revisions have the potential to transform deep‐seated societal understandings of education based on traditional hierarchies and teacher–student distinctions. [liminality, position, student consultant, learning, change]
Constructing Membership Identity through Language and Social Interaction: The Case of African American Children at Faith Missionary Baptist Church
Authors: Peele‐Eady Tryphenia B.
Published: February 2011

In this article, the author explores how African American children in a Black church Sunday school community in northern California developed positive membership identity. Focal participants were Sunday school children ages 9 to 12 and their Sunday school teachers. Drawn from a two‐year ethnographic study, data showed that adults prepared children for membership through an interactive framework of instruction, which also formed the base for communicative competence in the setting. The author describes this framework and offers new insight into conditions that give rise to African American student success. [African American children, church, identity, communicative competence]
Treatment and assessment of emergency department nausea and vomiting in Australasia: A survey of anti‐emetic management
Authors: Mee Michaela J , Egerton‐Warburton Diana , Meek Robert
Published: February 2011

Objective: To describe the treatment and assessment of emergency department nausea and vomiting (EDNV) in Australasia by Fellows of the Australasian College for Emergency Medicine (FACEM). To determine the influence of various factors on FACEM anti‐emetic choice. To compare the influence of drug effectiveness, side effects, cost and pharmacy directives on adult EDNV anti‐emetic choice between FACEM choosing the two most common first‐line agents.

Methods: A cross‐sectional survey of all FACEM practising in Australasian ED was conducted by mail‐out in February 2009.

Results: Of all FACEM surveyed 48.7% (532/1092) responded. The most common first‐line drugs for adult EDNV were metoclopramide (87.3%, 453/519), 5HT3 antagonists (7.9%, 41/519) and prochlorperazine (2.3%, 12/519). For paediatric EDNV, the most common first‐line agents were 5HT3 antagonists (86.2%, 307/356), metoclopramide (6.7%, 24/356) and promethazine (5.1%, 18/356). For most FACEM anti‐emetic choice was highly influenced by perceived drug efficacy (96.1%) and side effects (82.5%), and 32.9% of FACEM were highly influenced by drug cost. Few FACEM reported ED anti‐emetic protocols for adults (13.0%) or children (16.7%) in their ED. FACEM seldom used scales or tools to measure EDNV severity in adult (2.5%) or paediatric (3.4%) patients.

Conclusions: Fellows of the Australasian College for Emergency Medicine anti‐emetic choice in Australasian ED has been described. The main influences on anti‐emetic choice were patient age, perceived drug efficacy and drug side‐effect profiles.
TRAIT AND BEHAVIORAL THEORIES OF LEADERSHIP: AN INTEGRATION AND META‐ANALYTIC TEST OF THEIR RELATIVE VALIDITY
Authors: DERUE D. SCOTT , NAHRGANG JENNIFER D. , WELLMAN NED , HUMPHREY STEPHEN E.
Published: February 2011

The leadership literature suffers from a lack of theoretical integration (Avolio, 2007, American Psychologist, 62, 25–33). This article addresses that lack of integration by developing an integrative trait‐behavioral model of leadership effectiveness and then examining the relative validity of leader traits (gender, intelligence, personality) and behaviors (transformational‐transactional, initiating structure‐consideration) across 4 leadership effectiveness criteria (leader effectiveness, group performance, follower job satisfaction, satisfaction with leader). Combined, leader traits and behaviors explain a minimum of 31% of the variance in leadership effectiveness criteria. Leader behaviors tend to explain more variance in leadership effectiveness than leader traits, but results indicate that an integrative model where leader behaviors mediate the relationship between leader traits and effectiveness is warranted.
DOING GOOD, FEELING GOOD: EXAMINING THE ROLE OF ORGANIZATIONAL CITIZENSHIP BEHAVIORS IN CHANGING MOOD
Authors: GLOMB THERESA M. , BHAVE DEVASHEESH P. , MINER ANDREW G. , WALL MELANIE
Published: February 2011

This study investigates whether the altruism and courtesy dimensions of organizational citizenship behaviors (OCB) regulate mood at work. Social psychological theories of mood regulation suggest helping behaviors can improve individuals’ moods because helping others provides gratification and directs attention away from one's negative mood. We capture mood states prior to and following the enactment of OCBs using experience sampling methodology in a sample of managerial and professional employees over a 3‐week period. Results suggest altruism shows a pattern consistent with mood regulation; negative moods during the prior time period are associated with altruism and positive moods in the subsequent time period. The pattern of results for courtesy behaviors is only partially consistent with a mood regulation explanation. Consistent with theories of behavioral concordance, interaction results suggest individuals higher on Extroversion have more intense positive mood reactions after engaging in altruistic behaviors. Interactions with courtesy were not significant.
DOING COMPETENCIES WELL: BEST PRACTICES IN COMPETENCY MODELING
Authors: CAMPION MICHAEL A. , FINK ALEXIS A. , RUGGEBERG BRIAN J. , CARR LINDA , PHILLIPS GENEVA M. , ODMAN RONALD B.
Published: February 2011

The purpose of this article is to present a set of best practices for competency modeling based on the experiences and lessons learned from the major perspectives on this topic (including applied, academic, and professional). Competency models are defined, and their key advantages are explained. Then, the many uses of competency models are described. The bulk of the article is a set of 20 best practices divided into 3 areas: analyzing competency information, organizing and presenting competency information, and using competency information. The best practices are described and explained, practice advice is provided, and then the best practices are illustrated with numerous practical examples. Finally, how competency modeling differs from and complements job analysis is explained throughout.
Ecological economics of soil erosion: a review of the current state of knowledge
Authors: Adhikari Bhim , Nadella Karthik
Published: February 2011

The economics of land degradation has received relatively little attention until recent years. Although a number of studies have undertaken valuation of ecosystem services ranging from the global to the micro level, and quite a few studies have attempted to quantify the costs of soil erosion, studies that address the full costs of land degradation are still scarce. In this review, we attempt to analyze different land resource modeling and valuation techniques applied in earlier research and the type of data used in these analyses, and to assess their utility for different forms of land resource and management appraisal. We also report on the strengths and weaknesses of different valuation techniques used in studies on the economics of soil erosion, and the relevance of these valuation techniques. We make a case for the need for more appropriate models that can make the analysis more robust in estimating the economic costs of land degradation while recognizing the spatial heterogeneity in biophysical and economic conditions.
Ecological economics and institutional change
Authors: Krall Lisi , Klitgaard Kent
Published: February 2011

Ecological economics remains unfinished in its effort to provide a framework for transforming the economy so that it is compatible with biophysical limits. Great strides have been made in valuing natural capital and ecosystem services and recognizing the need to limit the scale of economic activity, but the question of how to effectively transform the economy to limit the scale of economic activity remains unclear. To gain clarity about the institutional changes necessary to limit the scale of economic activity, it is essential that ecological economics understands the limitations of its neoclassical roots and expands its theoretical framework to include how markets are embedded in social and institutional structures. This has long been the domain of institutional economics and heterodox political economy.
Evolutionary principles and their practical application
Authors: Hendry Andrew P. , Kinnison Michael T. , Heino Mikko , Day Troy , Smith Thomas B. , Fitt Gary , Bergstrom Carl T. , Oakeshott John , Jørgensen Peter S. , Zalucki Myron P. , Gilchrist George , Southerton Simon , Sih Andrew , Strauss Sharon , Denison Robert F. , Carroll Scott P.
Published: February 2011

Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design of harvesting regimes that minimize unwanted life‐history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently in these different fields, even though the underlying fundamental concepts are the same. We explore these fundamental concepts under four main themes: variation, selection, connectivity, and eco‐evolutionary dynamics. Within each theme, we present several key evolutionary principles and illustrate their use in addressing applied problems. We hope that the resulting primer of evolutionary concepts and their practical utility helps to advance a unified multidisciplinary field of applied evolutionary biology.
The evolution of new enzyme function: lessons from xenobiotic metabolizing bacteria versus insecticide‐resistant insects
Authors: Russell Robyn J. , Scott Colin , Jackson Colin J. , Pandey Rinku , Pandey Gunjan , Taylor Matthew C. , Coppin Christopher W. , Liu Jian‐Wei , Oakeshott John G.
Published: February 2011

Here, we compare the evolutionary routes by which bacteria and insects have evolved enzymatic processes for the degradation of four classes of synthetic chemical insecticide. For insects, the selective advantage of such degradative activities is survival on exposure to the insecticide, whereas for the bacteria the advantage is simply a matter of access to additional sources of nutrients. Nevertheless, bacteria have evolved highly efficient enzymes from a wide variety of enzyme families, whereas insects have relied upon generalist esterase‐, cytochrome P450‐ and glutathione‐S‐transferase‐dependent detoxification systems. Moreover, the mutant insect enzymes are less efficient kinetically and less diverged in sequence from their putative ancestors than their bacterial counterparts. This presumably reflects several advantages that bacteria have over insects in the acquisition of new enzymatic functions, such as a broad biochemical repertoire from which new functions can be evolved, large population sizes, high effective mutation rates, very short generation times and access to genetic diversity through horizontal gene transfer. Both the insect and bacterial systems support recent theory proposing that new biochemical functions often evolve from ‘promiscuous’ activities in existing enzymes, with subsequent mutations then enhancing those activities. Study of the insect enzymes will help in resistance management, while the bacterial enzymes are potential bioremediants of insecticide residues in a range of contaminated environments.
Koebner’s phenomenon in vitiligo: European position paper
Authors: van Geel Nanja , Speeckaert Reinhart , Taieb Alain , Picardo Mauro , Böhm Markus , Gawkrodger David J. , Schallreuter Karin , Bennett Dorothy C. , van der Veen Wietze , Whitton Maxine , Moretti Silvia , Westerhof Wiete , Ezzedine Khaled , Gauthier Yvon ,   on behalf of the other VETF members
Published: February 2011

Koebner’s phenomenon (KP) has been observed in a number of skin diseases, including vitiligo. Its clinical significance in vitiligo with respect to disease activity and course is still debatable, while its relevance for surgical techniques has been demonstrated in some reports. We present a literature review on the currently known facts about KP in vitiligo, including details of clinical, experimental, and histopathological changes. The consensus view is that there are still no methods to define and assess KP in vitiligo. A new classification is proposed to allow an evaluation of KP in daily practice or in experimental studies. However, many unanswered questions still remain after redefining KP in patients with vitiligo. Active research focusing on KP in vitiligo may not only provide unexpected clues in the pathogenesis of vitiligo but also help to tailor novel therapies against this chronic and often psychologically devastating skin disease.
Bi‐Criteria Scheduling of Surgical Services for an Outpatient Procedure Center
Authors: Gul Serhat , Denton Brian T. , Fowler John W. , Huschka Todd
Published: February 2011

Uncertainty in the duration of surgical procedures can cause long patient wait times, poor utilization of resources, and high overtime costs. We compare several heuristics for scheduling an Outpatient Procedure Center. First, a discrete event simulation model is used to evaluate how 12 different sequencing and patient appointment time‐setting heuristics perform with respect to the competing criteria of expected patient waiting time and expected surgical suite overtime for a single day compared with current practice. Second, a bi‐criteria genetic algorithm (GA) is used to determine if better solutions can be obtained for this single day scheduling problem. Third, we investigate the efficacy of the bi‐criteria GA when surgeries are allowed to be moved to other days. We present numerical experiments based on real data from a large health care provider. Our analysis provides insight into the best scheduling heuristics, and the trade‐off between patient and health care provider‐based criteria. Finally, we summarize several important managerial insights based on our findings.
Rotating Stall in a Single-Stage Axial Flow Compressor
Authors: Poensgen C. A. , Gallus H. E.
Published: February 2011

This paper describes the results on an experimental investigation of rotating stall flow inside a single-stage axial flow compressor. Tests were carried out in two steps. First, measurements were taken to investigate the transition process into rotating stall. The compressor starts into rotating stall via the “modal route” with a single rotating stall cell. Further throttling yields to a two-cell shape followed by a significant outlet pressure drop. Both transition processes are discussed in detail. Results from the Moore–Greitzer theory are compared with measured data. In a second step, measurements were taken to determine the three-dimensional unsteady structure of a fully developed rotating-stall cell. Based on unsteady total pressure and three-dimensional hot-wire data, the structure of a rotating stall cell could be resolved in detail upstream and downstream of the rotor. A typical part-span stall was found. By inserting the measured data into the Euler equations, convective and unsteady effects on the pressure fluctuations can be isolated. A dependence between the radial flow inside the stall cell and the unsteady flow accelerations was found.
Measurement of Tip-Clearance Flow in a Multistage, Axial Flow Compressor
Authors: Foley A. C. , Ivey P. C.
Published: February 2011

Detailed measurements using pneumatic probe traverses, blade static pressure tappings, and laser anemometry are made in the third stage of a large-scale, low-speed, four-stage, axial flow, research compressor. Inlet conditions show well-ordered “two-dimensional” flow from approximately 40 to 85 percent annulus span. Outside of this region, reduced total pressure due to upstream leakage losses and endwall effects results in high incidence to the following blade row. As a result, peak suction surface static pressure moves forward along the blade chord for both the hub and tip of stators and rotors. At the blade tip, however, the peak suction pressure is maintained with chord due to radial flow on the suction surface being entrained into the tip leakage jet. The extent of rotor chord for which this “entrainment” occurs increases with increasing rotor tip clearance gap. The leakage jet from both stators and rotors is seen to “roll up” into a vortex downstream of their respective blade rows.
Flow Analyses in a Single-Stage Propulsion Pump
Authors: Lee Y. T. , Hah C. , Loellbach J.
Published: February 2011

Steady-state analyses of the incompressible flow past a single-stage stator/rotor propulsion pump are presented and compared to experimental data. The purpose of the current study is to validate a numerical method for the design application of a typical propulsion pump and for the acoustic analysis based on predicted flowfields. A steady multiple-blade-row approach is used to calculate the flowfields of the stator and the rotor. The numerical method is based on a fully conservative control-volume technique. The Reynolds-averaged Navier–Stokes equations are solved along with the standard two-equation k–ε turbulence model. Numerical results for both mean flow and acoustic properties compare well with measurements in the wake of each blade row. The rotor blade has a thick boundary layer in the last quarter of the chord and the flow separates near the trailing edge. These features invalidate many Euler prediction results. Due to the dramatic reduction of the turbulent eddy viscosity in the thick boundary layer, the standard k–ε model cannot predict the correct local flow characteristics near the rotor trailing edge and in its near wake. Thus, a modification of the turbulence length scale in the turbulence model is applied in the thick boundary layer in response to the reduction of the turbulent eddy viscosity.
Numerical Analysis of Three-Dimensional Unsteady Hot Streak Migration and Shock Interaction in a Turbine Stage
Authors: Saxer A. P. , Felici H. M.
Published: February 2011

A three-dimensional unsteady flow computation has been performed for a transonic first turbine stage under the influence of streaks of hot gas exiting the combustion chamber. Realistic flow conditions are obtained by using an unequal stator-to-rotor pitch, a single-streak/multistator channel configuration, and periodic boundary conditions. The resulting unsteady shock wave system and the hot streak migration as well as the shock wave/streak interaction are presented and discussed. In addition, the time average of the periodic unsteady solution is analyzed and compared with a steady-state computation. The steady-state solution is analyzed and compared with a steady-state computation. The steady-state solution matches the time-averaged one in terms of the pressure field and the maximum stagnation temperature on the rotor blade surface. However, the rotor blade temperature patterns are different with a stronger radial secondary flow present in the time-averaged solution due to the retention of the circumferential streak variations at the stator/rotor interface.
Film Cooling of the Gas Turbine Endwall by Discrete-Hole Injection
Authors: Jabbari M. Y. , Marston K. C. , Eckert E. R. G. , Goldstein R. J.
Published: February 2011

Film cooling performance for injection through discrete holes in the endwall of a turbine blade is investigated. The effectiveness is measured at 60 locations in the region covered by injection. Three nominal blowing rates, two density ratios, and two approaching flow Reynolds numbers are examined. Analysis of the data reveals that even 60 locations are insufficient for the determination of the field of film cooling effectiveness with its strong local variations. Visualization of the traces of the coolant jets on the endwall surface, using ammonium-diazo-paper, provides useful qualitative information for the interpretation of the measurements, revealing the paths and interaction of the jets, which change with blowing rate and density ratio.
Simulation of Cooling Systems in Gas Turbines
Authors: Ebenhoch G. , Speer T. M.
Published: February 2011

The design of cooling systems for gas turbine engine blades and vanes calls for efficient simulation programs. The main purpose of the described program is to determine the complete boundary condition at the coolant side to support a temperature calculation for the solid. For the simulation of convection and heat pick up of the coolant flow, pressure loss, and further effects to be found in a rotating frame, the cooling systems are represented by networks of nodes and flow elements. Within each flow element the fluid flow is modeled by a system of ordinary differential equations based on the one-dimensional conservation of mass, momentum, and energy. In this respect, the computer program differs from many other network computation programs. Concerning cooling configurations in rotating systems, the solution for a single flow element or the entire flow system is not guaranteed to be unique. This is due to rotational forces in combination with heat transfer and causes considerable computational difficulties, which can be overcome by a special path following method in which the angular velocity is selected as the parameter of homotopy. Results of the program are compared with measurements for three applications.
Transition Modeling Effects on Turbine Rotor Blade Heat Transfer Predictions
Authors: Ameri A. A. , Arnone A.
Published: February 2011

The effect of transition modeling on the heat transfer predictions from rotating turbine blades was investigated. Three-dimensional computations using a Reynolds-averaged Navier–Stokes code were performed. The code utilized the Baldwin–Lomax algebraic turbulence model, which was supplemented with a simple algebraic model for transition. The heat transfer results obtained on the blade surface and the hub endwall were compared with experimental data for two Reynolds numbers and their corresponding rotational speeds. The prediction of heat transfer on the blade surfaces was found to improve with the inclusion of the transition length model and wake-induced transition effects over the simple abrupt transition model.
Flow and Heat Transfer Behavior in Transitional Boundary Layers With Streamwise Acceleration
Authors: Keller F. J. , Wang T.
Published: February 2011

The effects of streamwise acceleration on a two-dimensional heated boundary layer undergoing natural laminar-turbulent transition were investigated with detailed measurements of momentum and thermal transport phenomena. Tests were conducted over a heated flat wall with zero pressure-gradient and three levels of streamwise acceleration: K ≡ (v/U∞2) (d/U∞/dx) = 0.07, 0.16, and 0.25 × 10−6. Free-stream turbulence intensities were maintained at approximately 0.5 percent for the baseline case and 0.4 percent for the accelerating cases. A miniature three-wire probe was used to measure mean velocity and temperature profiles, Reynolds stresses, and Reynolds heat fluxes. Transition onset and end were inferred from Stanton numbers and skin-friction coefficients. The results indicate that mild acceleration delays transition onset and increases transition length both in terms of distance, x, and Reynolds number based on x. Transition onset and length are relatively insensitive to acceleration in terms of momentum thickness Reynolds number. This is supported by the boundary layer thickness and integral parameters, which indicate that a favorable pressure gradient suppresses boundary layer growth and development in the transition region. Heat transfer rates and temperature profiles in the late-transition and early-turbulent regions lag behind the development of wall shear stress and velocity profiles. This lag increases as K increases, indicating that the evolution of the heat transport is slower than that of the momentum transport. Comparison of the evolution of rms temperature fluctuations to the evolution of Reynolds normal stresses indicates a similar lag in the rms temperature fluctuations.
Design and Test of a Small, High Pressure Ratio Radial Turbine
Authors: Jones A. C.
Published: February 2011

This paper describes the aerodynamic design and rig test of a radial inflow turbine having a rotor tip diameter of 4.58 inches. The single-stage turbine was designed for use in the Sundstrand Power Systems (SPS) T-100 Multipurpose Small Power Unit (MPSPU). The T-100 is a small, single-shaft, simple-cycle gas turbine engine intended for airborne, vehicular, and ground-based auxiliary power application. Nominal power output of the engine is 50 hp, with growth capability to 100 hp with minimal modification. Aggressive specific fuel consumption goals for the engine led to a demanding turbine efficiency target of 87 percent total to static, referred to exhaust diffuser exit, at an expansion ratio of 5.7:1 and a flow rate of 0.73 lb/s. Details of the design approach are given, together with test results from the turbodrive rig. The results include overall stage mapping and rotor exit surveys.
Windage Heating of Air Passing Through Labyrinth Seals
Authors: Millward J. A. , Edwards M. F.
Published: February 2011

The viscous drag on rotating components in gas turbine engines represents both a direct loss of power from the cycle and an input of heat into the secondary (cooling) air system. Hotter cooling air in turn means increased flow requirements. The effects of windage on performance are therefore compounded. To facilitate accurate temperature predictions of highly stressed components, information is needed on windage characteristics of all elements in the secondary cooling system. Much information is available in the literature for disks, cones, cylinders, bolts, etc., but little has been published on windage heating in high-speed seals. Results are presented for experiments carried out (at representative nondimensional conditions) on different designs of labyrinth seals. The results are compared with values calculated from the simple momentum balance theory suggested by McGreeham and Ko [13] and with several values determined from CFD analysis.
Velocity-Stress Equations for Waves in Solids of Hexagonal Symmetry Solved by the Space-Time CESE Method
Authors: Yang Lixiang , Chen Yung-Yu , Yu Sheng-Tao John
Published: February 2011

This paper reports an extension of the space-time conservation element and solution element (CESE) method to simulate stress waves in elastic solids of hexagonal symmetry. The governing equations include the equation of motion and the constitutive equation of elasticity. With velocity and stress components as the unknowns, the governing equations are a set of 9, first-order, hyperbolic partial differential equations. To assess numerical accuracy of the results, the characteristic form of the equations is derived. Moreover, without using the assumed plane wave solution, the one-dimensional equations are shown to be equivalent to the Christoffel equations. The CESE method is employed to solve an integral form of the governing equations. Space-time flux conservation over conservation elements (CEs) is imposed. The integration is aided by the prescribed discretization of the unknowns in each solution element (SE), which in general does not coincide with a CE. To demonstrate this approach, numerical results in the present paper include one-dimensional expansion waves in a suddenly stopped rod, two-dimensional wave expansion from a point in a plane, and waves interacting with interfaces separating hexagonal solids with different orientations. All results show salient features of wave propagation in hexagonal solids and the results compared well with the available analytical solutions.