bluuebunny/crossref_metadata_2025 huggingface dataset:
Emotional effects of startling background music during reading news reports: The moderating influence of dispositional BIS and BAS sensitivities
Authors: RAVAJA NIKLAS , KALLINEN KARI
Published: June 2004

We examined the moderating influence of dispositional behavioral inhibition system (BIS) and behavioral activation system (BAS) sensitivities on the relationship of startling background music with emotion‐related subjective and physiological responses elicited during reading news reports, and with memory performance among 26 adult men and women. Physiological parameters measured were respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), and facial electromyography (EMG). The results showed that, among high BAS individuals, news stories with startling background music were rated as more interesting and elicited higher zygomatic EMG activity and RSA than news stories with non‐startling music. Among low BAS individuals, news stories with startling background music were rated as less pleasant and more arousing and prompted higher EDA. No BIS‐related effects or effects on memory were found. Startling background music may have adverse (e.g., negative arousal) or beneficial effects (e.g., a positive emotional state and stronger positive engagement) depending on dispositional BAS sensitivity of an individual. Actual or potential applications of this research include the personalization of media presentations when using modern media and communications technologies.
Maternal sensitivity behavior and infant crying, fussing and contented behavior: The effects of mother's experienced social support
Authors: KIVIJÄRVI MARJA , RÄIHÄ HANNELE , VIRTANEN SAMI , LERTOLA KALLE , PIHA JORMA
Published: June 2004

Maternal sensitivity behavior, mother's experienced difficulties, experienced social support, and the amount of infant's crying, fussing and contented behavior were studied when the infants were 3 and 12 months of age. Fifty‐seven Finnish low‐risk mothers’ sensitivity behavior was assessed by the Parent‐Child Early Relational Assessment method. Infant's crying behavior was assessed by the Baby's Day Record and by the Crying Patterns Questionnaire. The Social Support Questionnaires (SSQ 1 and 2) were used to evaluate mother's experienced difficulties and support. The infants of More Sensitive (MS) mothers were more contented than those with Less Sensitive (LS) mothers. The MS mothers experienced fewer difficulties with their infants and experienced more support from their best friend and their husband than LS mothers. In addition, some gender differences were found concerning infant behavior.
The enactment effect is due to more than guesses and beliefs
Authors: HELSTRUP TORE
Published: June 2004

Three experiments examined whether the enactment effect – that is, higher recall of enacted than of corresponding non‐enacted information – might be explained by guessing rates and performance expectancies. Experiment 1 checked whether the guessing rate of target items would be higher as a result of a narrowed sampling space defined by the enactment condition. By means of pre‐experimental instructions, the subjects in Experiments 2 and 3 were induced to expect respectively a positive enactment effect, a negative enactment effect, or no difference in amount of recall of enacted and non‐enacted materials. Experiment 2 had a within‐subject design, Experiment 3 a between‐subject design. The experiments failed to support the proposed explanations.
Fairness heuristic theory is an empirical framework: A reply to Árnadóttir
Authors: BOS KEES VAN DEN , ALLAN LIND E.
Published: June 2004

In this article on fairness heuristic theory, we point out some important flaws in Árnadóttir's (2002) claim that fairness heuristic theory is “not empirical,” by which Árnadóttir meant that theory's predictions are knowable a priori, and are not contingent upon circumstances. To this end, we demonstrate that empirically testing effects predicted by fairness heuristic theory was and is important because this showed that the theory's propositions are not necessarily knowable a priori and are contingent upon circumstances. This implies that, according to Árnadóttir's definition, fairness heuristic theory clearly is an empirical framework. It would have been helpful if Árnadóttir had studied the fairness literature more thoroughly (as this would have easily revealed fairness heuristic theory to be not knowable a priori and to be contingent upon circumstances) and also if she had pointed out which of our studies fail to follow her line of reasoning. Our reply was written not as an attempt to defend fairness heuristic theory as we applaud, indeed are honored by, attempts to scrutinize our work in progress. Our only aim here was to point at some important flaws in the Árnadóttir article, because we think these will hamper rather than advance the science of psychology of justice.
Standards, Accountability, and School Reform
Authors: Darling-Hammond Linda
Published: June 2004

The standards-based reform movement has led to increased emphasis on tests, coupled with rewards and sanctions, as the basis for “accountability” systems. These strategies have often had unintended consequences that undermine access to education for low-achieving students rather than enhancing it. This article argues that testing is information for an accountability system; it is not the system itself. More successful outcomes have been secured in states and districts, described here, that have focused on broader notions of accountability, including investments in teacher knowledge and skill, organization of schools to support teacher and student learning, and systems of assessment that drive curriculum reform and teaching improvements.
High-Stakes Accountability in Urban Elementary Schools: Challenging or Reproducing Inequality?1
Authors: Diamond John B. , Spillane James P.
Published: June 2004

In this article, the authors use data from interviews and observations in four urban elementary schools—two high-performing and two probation schools—to examine how schools respond to high-stakes accountability policies. The authors show that school responses to high-stakes accountability depend on the schools’ accountability status. In probation schools, responses focus narrowly on complying with policy demands, focusing on improving the performance of certain students, within benchmark grades, and in certain subject areas. In contrast, higher performing schools emphasize enhancing the performance of all students regardless of grade level and across all subject areas. Given the concentration of poor students and students of color in the lowest performing schools, the authors conclude that issues of educational equity need to be given greater consideration in the implementation of high stakes accountability policies.
Standards Gaps: Unintended Consequences of Local Standards-Based Reform
Authors: Sandholtz Judith Haymore , Ogawa Rodney T. , Scribner Samantha Paredes
Published: June 2004

In response to the establishment of standards by states and professional organizations, many local school districts have adopted a standards-based curriculum. The expressed purpose of standards is to improve student academic performance by providing teachers with a common sequence of targets at which to aim instruction. In this study, we examine unintended consequences of a school district's standards-based reform effort. Though the district intended to enhance student achievement and equalize educational opportunities for students, it instead caused the evolution of what can be called standards gaps, which resulted in differentiated curriculum and instruction along lines of students’ academic ability.
Accountability Policies and Teacher Decision Making: Barriers to the Use of Data to Improve Practice
Authors: Ingram Debra , Louis Karen Seashore , Schroeder Roger G.
Published: June 2004

One assumption underlying accountability policies is that results from standardized tests and other sources will be used to make decisions about school and classroom practice. We explore this assumption using data from a longitudinal study of nine high schools nominated as leading practitioners of Continuous Improvement (CI) practices. We use the key beliefs underlying continuous improvement—derived from educational applications of Deming's TQM models—and organizational learning to analyze teachers’ responses to district expectations that they would use data to assess their own, their colleagues’, and their schools’ effectiveness and to make improvements. The findings suggest that most teachers are willing, but they have significant concerns about the kind of information that is available and how it is used to judge their own and colleagues’ performance. Our analysis reveals some cultural assumptions that are inconsistent with accountability policies and with theories of continuous improvement and organizational learning. We also identify barriers to use of testing and other data that help to account for the limited impacts.
Relaxation Treatment Administered by School Nurses to Adolescents With Recurrent Headaches
Authors: Fichtel Åsa , Larsson Bo
Published: June 2004

Objective.—To study the outcome of two different forms of relaxation training administered by school nurses to adolescents suffering from recurrent headaches in an effectiveness study.

Methods.—A total of 11 school nurses were randomized to administer one of the two treatments to 63 adolescents. A post hoc group with 42 untreated subjects, matched for headache diagnosis, sex, and age were included as a control group.

Results.—The results showed no pre‐post differences in headache reduction between the treatment groups, however, subjects treated with either of the two relaxation approaches were significantly more improved than those in the post hoc group on total headache activity and headache‐free days. Clinical improvement (at least 50% improvement) was attained among 19% of the treated subjects as compared to 7% for those in the post hoc group, a nonsignificant difference. Higher functional disability predicted a worse outcome, and positive self‐statements predicted better outcome. Altogether, these variables accounted for 29% of the outcome variance in the total headache activity.

Conclusions.—In the present study, outcomes of relaxation training as administered by school nurses were not found to be as powerful as similar treatments provided for adolescents with migraine or tension‐type headache in the previous controlled studies of clinic as well as school samples. It is likely that the school nurses need to be more thoroughly trained and informed to achieve cost‐effective improvement. Presently, it is suggested that the relaxation training should not be used as a part of regular treatment in the school health care for adolescents with recurrent headaches until further evidence is provided.
Self‐Reported Headache Frequency and Features Associated With Frequent Headaches in Canadian Young Adolescents
Authors: Gordon K. E. , Dooley J. M. , Wood E. P.
Published: June 2004

Objective.—To explore the associated factors for frequent headache among young adolescent Canadians.

Methods.—We analyzed the self‐administered questionnaire microdata files of the National Longitudinal Survey of Children and Youth (NLSCY: 1996 to 1997). Two thousand and ninety respondents representing 793,100 Canadian youth aged 12 to 13 years were asked how often they had headaches in the previous 6 months.

Results.—Of the 2090 adolescents, 1998 (96%) responded. Frequent headaches of “about once a week” or more often were reported by 26.6% of them aged 12 to 13 years (95% CI: 24.2, 28.6). Frequent headaches appear to be associated with a plethora of risk factors germane to the life experience of these young adolescents. All factors were significant at P < .0001 by chi‐square analysis and can be loosely categorized as school‐related, lifestyle‐related, or involving mental health. A multivariate Classification and Regression Tree (CART) analysis models frequent headaches on a depression scale, a self‐esteem scale, and ever having smoked, with 60% sensitivity, and 65% specificity.

Conclusions.—The NLSCY reveals a remarkable insight into headache frequency and the life experience of Canada's young adolescents with frequent headaches.
The Medical Costs of Migraine and Comorbid Anxiety and Depression
Authors: Pesa Jacqueline , Lage Maureen J.
Published: June 2004

Objective.—To examine the direct medical costs associated with migraine, when diagnosed alone and in conjunction with anxiety and/or depression in adults and children.

Background.—Migraine is a common disorder that can often be accompanied by comorbid anxiety and/or depression. Given the prevalence of migraine and the likelihood for comorbid conditions, it is not surprising that migraine is extremely costly for society.

Methods.—Migraine cohorts were identified in a 1999‐2000 database capturing inpatient, outpatient, and prescription drug services from approximately 45 large employers. Four cohorts of adults (migraine only, migraine and anxiety, migraine and depression, migraine and both conditions), and two cohorts of children (migraine only, migraine and anxiety and/or depression), were compared to respective “healthy” cohorts. t‐statistics were used to capture differences in costs between the migraine cohorts and the healthy cohorts whereas ANOVA was used to test for differences in costs between subgroups of migraine sufferers.

Results.—Compared to nonmigraineurs, adults and children with migraine had significantly higher total direct medical costs in all examined categories (P < .0001) ($7,089 vs $2,923 adults; $4,272 vs $1,400 children). For adults, the presence of depression and/or anxiety along with migraine equated to significantly greater total direct medical costs when compared to their matched healthy cohorts (P < .0001) ($12,642 vs $5,179 anxiety; $11,290 vs $3,135 depression). Children with migraine and either anxiety or depression (or both) incurred an average of $9,875 in total direct medical costs as compared with only $1,165 for healthy comparators. For children and adults, the presence of comorbid anxiety or depression was associated with significantly higher medical costs when compared to migraine alone (P < .0001).

Conclusions.—This analysis quantifies the economic impact of a migraine diagnosis for both adults and children. The results of this analysis demonstrate that individuals identified as migraineurs have significantly higher medical costs than healthy comparators, with or without comorbid anxiety and/or depression. This study also suggests that clinicians should be aware that while proper treatment of migraine with effective acute and prophylactic therapy is important, attention must also be directed to comorbid conditions.
Impact of Headache on Quality of Life in a General Population Survey in France (GRIM2000 Study)
Authors: Duru Gérard , Auray Jean‐Paul , Gaudin Anne‐Françoise , Dartigues Jean‐François , Henry Patrick , Lantéri‐Minet Michel , Lucas Christian , Pradalier André , Chazot Guy , Hasnaoui Abdelkader El
Published: June 2004

Objectives.—The objectives of this study were to determine the impact of headache on health‐related quality of life in a nationwide sample of the French general population using a disease‐specific measure, the Qualité de Vie et Migraine (QVM), to compare quality of life in subjects reporting different headache to types, and to evaluate the relationship between quality of life and severity, frequency, associated disability, and treatment responsiveness of headaches.

Methods.—The QVM questionnaire was included within a large epidemiological survey of 1486 headache sufferers. Diagnosis was assigned retrospectively using an algorithm based on the International Headache Society classification. Headache severity was assessed with the MIGSEV scale and disability with the MIDAS scale.

Results.—The mean global QVM score in the sample was 80.2. Quality of life was poorer in subjects with chronic daily headache (QVM score: 66.2) than in those with migraine (QVM score: 76.7), while those with other forms of episodic headache had the best quality of life (QVM score: 91.7). Quality‐of‐life scores were correlated with frequency, severity, disability, and treatment resistance of headaches (P < .001).

Conclusion.—The QVM scale is a sensitive tool to measure health‐related quality of life in headache sufferers in the general population.
Headache in Sleep Apnea Syndrome
Authors: Idiman Fethi , Oztura Ibrahim , Baklan Baris , Özturk Vesile , Kursad Fatma , Pakoz Burak
Published: June 2004

Objective.—To find out whether there is a relationship between the headache characteristics and polysomnographic findings in patients with prediagnosis of the sleep apnea syndrome (SAS) and, if there is, to search for its possible cause.

Background.—Chronic morning headache is considered by many to be an important part of the SAS. Some reports support this relationship, and some do not.

Methods.—We questioned 75 patients with SAS about headache. Headaches were classified according to the International Headache Society (IHS‐88) system. We evaluated the relationship between headache and polysomnographic findings.

Results.—There was no statistically significant relationship between headache and apnea hypopnea index (AHI) or minimal oxygen saturation (P > .05).

Conclusions.—We could not demonstrate a statistically significant relationship between headache, AHI, and minimal oxygen saturation in our patients with SAS.
Obstructive Sleep Apnea and Cluster Headache
Authors: Graff‐Radford Steven B. , Newman Alan
Published: June 2004

A patient with cluster headache often wakes from sleep. The relationship to sleep apnea has been described. This study sought to confirm the relationship cluster may have with sleep apnea.

Methods.—Thirty‐nine consecutive patients diagnosed with episodic cluster headache according to the International Headache Society (IHS) criteria were sent for polysomnographic studies. All patients were in an active phase when they were in the study. Patients were told of the proposed relationship and were allowed to choose a sleep laboratory close to their home.

Results.—Thirty‐one patients with episodic cluster headache completed an overnight polysomnographic study. Twenty‐three were male and eight female. The average age was 51 years (range 33 to 78 years). The average weight was 173 pounds (range 117 to 260 pounds). A total of 80.64% had sleep apnea (25/31). Average respiratory depression index (RDI) was 19.0 (SD 14.6) with 6 patients having no apnea, 10 having mild, 11 having moderate, and 4 having severe apnea (RDI < 5 = none; RDI 5 to 20 mild; RDI 20 to 40 moderate; RDI > 40 severe). Oxygen saturation decreased on average to 88.4% SD 4.5. Sleep efficiency was 76.2% (SD 13.4).

Conclusions.—The data closely approximate those of Chervin et al, where 80% had RDI > 5. The relationship sleep apnea has in the perpetuation or precipitation of cluster headache is still to be determined. There are some reports that treatment stops the cluster but there is no prospective study. The high incidence (80.64%) seen in this population suggests the cluster patient should receive a sleep evaluation and perhaps intervention with continuous positive airway pressure (CPAP) or an appropriate dental device.
Nummular Headache: A Prospective Series of 14 New Cases
Authors: Pareja Juan A. , Pareja Julia , Barriga Francisco J. , Barón Manuel , Dobato José L. , Pardo Javier , Sánchez Carmen , Vela Lydia
Published: June 2004

Objective.—To study the clinical features of nummular headache (NH) and get an approach to its epidemiology.

Background.—NH has been recently described as a primary disorder characterized by head pain exclusively felt in a small rounded area typically 2‐6 cm in diameter.

Methods.—Through a 1‐year period we have studied all patients referred to our neurologic clinic because of head pain exclusively felt in a small‐circumscribed area, and not attributed to another disorder. All the patients had normal neurological, analytical, and neuroimaging examinations. All the patients belonged within the same regional care system comprising 220,000 inhabitants.

Results.—A total of 11 females and 3 males were studied. Based in our hospital series, the incidence was 6.4/100,000/year. The mean age at the onset was 38 years (range: 13‐72). Only three patients had another concurrent headache: migraine (n = 2), and trigeminal neuralgia (n = 1) which proved to have an independent course. All the patients reported head pain exclusively felt in either a rounded (n = 12) of 1‐6 cm diameter, or an oval area (n = 2) of 5 × 3 cm, and 2 × 3 cm, respectively. Both size and shape of the painful area remained constant since the onset of symptoms. The location of the symptomatic area was mostly parietal (n = 7) or temporal (n = 5), but also frontal (n = 1) and in occiput (n = 1). The background pain was mostly mild‐to‐moderate, but also moderate‐to‐severe pain was reported. Exacerbations—either spontaneous or precipitated by combing hair or touching the symptomatic area—were reported by 8 patients. The temporal pattern was chronic‐continuous (n = 7) and episodic (n = 7). Ten patients reported a variable combination of sensory disturbance (tenderness, hypoesthesia, hyperalgesia, and allodynia) in the symptomatic area. There were no autonomic accompaniments. Treatment was generally not necessary. When needed, standard oral doses of paracetamol usually sufficed.

Conclusions.—NH emerges as a clear‐cut clinical picture. It is a noninfrequent primary headache. The particular topography suggests the pain has a probable epicranial source conveyed by, or originated in, one/a few terminal branch(es) of the cutaneous nerves of the scalp.
A Little Fire in BurgerLand
Authors: Brown D.F. , Allen Terry
Published: June 2004

“Don't let yourself get overwhelmed  with questions; just take it easy.”

—Wittgenstein
The Vietnam Syndrome* and the American People
Authors: Summers Harry G.
Published: June 2004

*This essay is the opening chapter of On Strategy II: A Critical Analysis of the Gulf War (Dell, 1992: 7–21). It is published here by generous permission of Colonel Summers.
The American Canon Wars: A View from Mexico
Authors: Ryan Mark B.
Published: June 2004

Cualquiera que haya experimentado la vida académica de los Estados Unidos, en la última década, sabe que el campus se ha convertido en un campo de batalla de las llamadas “Guerras Culturales.” En su vida política y social, los Estados Unidos han sufrido grandes tensiones debido a su carácter multiétnico. Más especialmente, se han enfocado en las “guerras por la verdad sagrada”: la controversia sobre jerarquías previamente asumidas sobre el trabajo literario e intelectual de ciertos individuos que ha sido acuñado como valor nacional. En México donde la educación superior es más especializada y con un enfoque más profesional, se discute muy poco sobre cuestiones de esta índole, a pesar de las diversidades lingüisticas y culturales de este país. Sin embargo, en los Estados Unidos, las tensiones sociales son generadas o influidas, en muchas ocasiones, por la naturaleza académica liberal de las universidades norteamericanas.
pH‐Independent Endocytic Cycling of the Chemokine Receptor CCR5
Authors: Signoret Nathalie , Christophe Thierry , Oppermann Martin , Marsh Mark
Published: June 2004

Following agonist activation, the chemokine receptor CCR5 is internalised through clathrin‐coated pits and delivered to recycling endosomes. Subsequently, ligand‐ free and resensitised receptors are recycled to the cell surface. Currently little is known of the mechanisms regulating resensitisation and recycling of this G‐protein coupled receptor. Here we show that raising the pH of endocytic compartments, using bafilomycin A, monensin or NH4Cl, does not significantly affect CCR5 endocytosis, recycling or dephosphorylation. By contrast, these reagents inhibited recycling of another well‐characterised G protein coupled receptor, the β2‐adrenergic receptor, following agonist‐induced internalisation. CCR5‐bound RANTES (CCL5) and MIP‐1β (CCL4) only exhibit pH‐dependent dissociation at pH < 4.0, below the values normally found in endocytic organelles. Although receptor‐agonist dissociation is not dependent on low pH, the subsequent degradation of released chemokine is inhibited in the presence of reagents that raise endosomal pH. Our data show that exposure to low pH is not required for RANTES or MIP‐1β dissociation from CCR5, or for recycling of internalised CCR5 to the cell surface.
The Development of High-Performance Leaf Seals
Authors: Nakane H. , Maekawa A. , Akita E. , Akagi K. , Nakano T. , Nishimoto S. , Hashimoto S. , Shinohara T. , Uehara H.
Published: June 2004

Recently, from the environmental point of view, demand for a combined cycle plant is increasing, and superior gas turbine performance is being rapidly promoted at the same time. As one of the key technologies for superior performance, reduction of secondary air leakage, which is necessary for blade cooling and bearing sealing, is required. Especially, reduction of air leakage through rotating parts and stationary parts clearance is critical.
Introduction and Performance Prediction of a Nutating-Disk Engine
Authors: Korakianitis T. , Meyer L. , Boruta M. , McCormick H. E.
Published: June 2004

A new type of internal combustion engine and its thermodynamic cycle are introduced. The core of the engine is a nutating nonrotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The accumulator and combustion chamber are kept at constant pressures. The engine has a few analogies with piston-engine operation, but like a gas turbine it has dedicated spaces and devices for compression, burning, and expansion. The thermal efficiency is similar to that of comparably sized simple-cycle gas turbines and piston engines. For the same engine volume and weight, this engine produces less specific power than a simple-cycle gas turbine, but approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The engine has advantages in the 10 kW to 200 kW power range. This paper introduces the geometry and thermodynamic model for the engine, presents typical performance curves, and discusses the relative advantages of this engine over its competitors.
Degradation Effects on Combined Cycle Power Plant Performance—Part III: Gas and Steam Turbine Component Degradation Effects
Authors: Zwebek A. I. , Pilidis P.
Published: June 2004

This paper presents an investigation of the degradation effects that gas and steam turbine cycles components have on combined cycle (CCGT) power plant performance. Gas turbine component degradation effects were assessed with TurboMatch, the Cranfield Gas Turbine simulation code. A new code was developed to assess bottoming cycle performance deterioration. The two codes were then joined to simulate the combined cycle performance deterioration as a whole unit. Areas examined were gas turbine compressor and turbine degradation, HRSG degradation, steam turbine degradation, condenser degradation, and increased gas turbine back pressure due to HRSG degradation. The procedure, assumptions made, and the results obtained are presented and discussed. The parameters that appear to have the greatest influence on degradation are the effects on the gas generator.
Fuel-Cooled Thermal Management for Advanced Aeroengines
Authors: Huang He , Spadaccini Louis J. , Sobel David R.
Published: June 2004

Fuel-cooled thermal management, including endothermic cracking and reforming of hydrocarbon fuels, is an enabling technology for advanced aero engines and offers potential for cycle improvements and pollutant emissions control in gas turbine engine applications. The successful implementation of this technology is, however, predicated on the use of conventional multicomponent hydrocarbon fuels and an understanding of the combustion characteristics of the reformed fuel mixture. The objective of this research is to develop and demonstrate the technologies necessary for utilizing conventional multicomponent hydrocarbon fuels for fuel-cooled thermal management, including the development of the endothermic potential of JP-7 and JP-8+100, a demonstration of the combustion of supercritical/endothermic fuel mixtures, and conceptual design of a fuel-air heat exchanger. The ability to achieve high heat sinks with existing jet fuels (e.g., JP-7 and JP-8+100) was demonstrated with a bench-scale test rig operating under flow conditions and passage geometries simulative of practical heat exchangers for aircraft and missile applications. Key measurements included fuel heat sink, reaction products, and extent of conversion. Full-scale sector rig tests were conducted to characterize the combustion and emissions of supercritical jet fuel, and demonstrate the safety and operability of the fuel system, including a fuel-air heat exchanger.
Critical Plane Fatigue Modeling and Characterization of Single Crystal Nickel Superalloys
Authors: Naik Rajiv A. , DeLuca Daniel P. , Shah Dilip M.
Published: June 2004

Single crystal nickel-base superalloys deform by shearing along 〈111〉 planes, sometimes referred to as “octahedral” slip planes. Under fatigue loading, cyclic stress produces alternating slip reversals on the critical slip systems which eventually results in fatigue crack initiation along the “critical” octahedral planes. A “critical plane” fatigue modeling approach was developed in the present study to analyze high cycle fatigue (HCF) failures in single crystal materials. This approach accounted for the effects of crystal orientation and the micromechanics of the deformation and slip mechanisms observed in single crystal materials. Three-dimensional stress and strain transformation equations were developed to determine stresses and strains along the crystallographic octahedral planes and corresponding slip systems. These stresses and strains were then used to calculate several multiaxial critical plane parameters to determine the amount of fatigue damage and also the “critical planes” along which HCF failures would initiate. The computed fatigue damage parameters were used along with experimentally measured fatigue lives, at 1100°F, to correlate the data for different loading orientations. Microscopic observations of the fracture surfaces were used to determine the actual octahedral plane (or facet) on which fatigue initiation occurred. X-ray diffraction measurements were then used to uniquely identify this damage initiation facet with respect to the crystal orientation in each specimen. These experimentally determined HCF initiation planes were compared with the analytically predicted “critical planes.”
Dynamic Response of Squeeze Film Dampers Operating With Bubbly Mixtures
Authors: San Andres Luis , De Santiago Oscar C.
Published: June 2004

Squeeze film dampers (SFDs) aid to attenuate vibrations in compressors and turbines while traversing critical speeds. In actual applications, gas ingestion from the environment may lead to the formation of a foamy lubricant that degrades the rotor/bearing system dynamic performance. Impact and imbalance response tests conducted on a rigid rotor supported on SFDs, and aimed to emulate the pervasive effect of air ingestion into the damper film lands, are reported. Two types of squeeze film damper support the test rotor, one is a conventional cylindrical design with a squirrel cage-type elastic support, and the other is a compact four-pad damper with integral wire EDM elastic supports. Both dampers have identical diameter and radial clearance. Controlled (air in oil) mixtures ranging from pure oil to all air conditions are supplied to the SFDs, and measurements of the transient rotor response to calibrated impact loads are conducted. System damping coefficients, identified from acceleration/load transfer functions, decrease steadily as the air content in the mixture increases. However, measurements of the rotor synchronous imbalance response conducted with a lubricant bubbly mixture (50% air volume) show little difference with test results obtained with pure lubricant supplied to the dampers. The experimental results show that air entrainment is process and device-dependent, and that small amounts of lubricant enable the effective action of SFDs when the rotor traverses a critical speed.
Gas Turbine Test Parameters Corrections Including Operation With Water Injection
Authors: Mathioudakis K.
Published: June 2004

Methods for correcting data from gas turbine acceptance testing are discussed, focusing on matters which are not sufficiently covered by existing standards. First a brief outline is presented of the reasoning on which correction curves are based. Typical performance correction curves are shown together with the method of calculating mass flow rate and turbine inlet temperature from test data. A procedure for verifying guarantee data at a specific operating point is then given. Operation with water injection is then considered. Ways of correcting performance data are proposed, and the reasoning of following such a procedure is discussed. Corrections for water amount as well as power and efficiency are discussed. Data from actual gas turbine testing are used to demonstrate how the proposed procedure can be applied in actual cases of acceptance testing.
A Computer Code for Gas Turbine Engine Weight and Disk Life Estimation
Authors: Tong Michael T. , Halliwell Ian , Ghosn Louis J.
Published: June 2004

Reliable engine-weight estimation at the conceptual design stage is critical to the development of new aircraft engines. It helps to identify the best engine concept amongst several candidates. In this paper, the major enhancements to NASA’s engine-weight estimate computer code (WATE) are described. These enhancements include the incorporation of improved weight-calculation routines for the compressor and turbine disks using the finite difference technique. Furthermore, the stress distribution for various disk geometries was also incorporated, for a life-prediction module to calculate disk life. A material database, consisting of the material data of most of the commonly used aerospace materials, has also been incorporated into WATE. Collectively, these enhancements provide a more realistic and systematic way to calculate the engine weight. They also provide additional insight into the design tradeoff between engine life and engine weight. To demonstrate the new capabilities, the enhanced WATE code is used to perform an engine weight/life tradeoff assessment on a production aircraft engine.
Saturation Mutagenesis of
Burkholderia cepacia
R34 2,4-Dinitrotoluene Dioxygenase at DntAc Valine 350 for Synthesizing Nitrohydroquinone, Methylhydroquinone, and Methoxyhydroquinone
Authors: Keenan Brendan G. , Leungsakul Thammajun , Smets Barth F. , Wood Thomas K.
Published: June 2004

Saturation mutagenesis of the 2,4-dinitrotoluene dioxygenase (DDO) of
Burkholderia cepacia
R34 at position valine 350 of the DntAc α-subunit generated mutant V350F with significantly increased activity towards
o
-nitrophenol (47 times),
m
-nitrophenol (34 times), and
o
-methoxyphenol (174 times) as well as an expanded substrate range that now includes
m
-methoxyphenol,
o
-cresol, and
m
-cresol (wild-type DDO had no detectable activity for these substrates). Another mutant, V350M, also displays increased activity towards
o
-nitrophenol (20 times) and
o
-methoxyphenol (162 times) as well as novel activity towards
o
-cresol. Products were synthesized using whole
Escherichia coli
TG1 cells expressing the recombinant R34
dntA
loci from pBS(Kan)R34, and the initial rates of product formation were determined at 1 mM substrate by reverse-phase high-pressure liquid chromatography. V350F produced both nitrohydroquinone at a rate of 0.75 ± 0.15 nmol/min/mg of protein and 3-nitrocatechol at a rate of 0.069 ± 0.001 nmol/min/mg of protein from
o
-nitrophenol, 4-nitrocatechol from
m
-nitrophenol at 0.29 ± 0.02 nmol/min/mg of protein, methoxyhydroquinone from
o
-methoxyphenol at 2.5 ± 0.6 nmol/min/mg of protein, methoxyhydroquinone from
m
-methoxyphenol at 0.55 ± 0.02 nmol/min/mg of protein, both methylhydroquinone at 1.52 ± 0.02 nmol/min/mg of protein and 2-hydroxybenzyl alcohol at 0.74 ± 0.05 nmol/min/mg of protein from
o
-cresol, and methylhydroquinone at 0.43 ± 0.1 nmol/min/mg of protein from
m
-cresol. V350M produced both nitrohydroquinone at a rate of 0.33 nmol/min/mg of protein and 3-nitrocatechol at 0.089 nmol/min/mg of protein from
o
-nitrophenol, methoxyhydroquinone from
o
-methoxyphenol at 2.4 nmol/min/mg of protein, methylhydroquinone at 1.97 nmol/min/mg of protein and 2-hydroxybenzyl alcohol at 0.11 nmol/min/mg of protein from
o
-cresol. The DDO variants V350F and V350M also exhibited 10-fold-enhanced activity towards naphthalene (8 ± 2.6 nmol/min/mg of protein), forming (1
R
,2
S
)-
cis
-1,2-dihydro-1,2-dihydroxynaphthalene. Hence, mutagenesis of wild-type DDO through active-site engineering generated variants with relatively high rates toward a previously uncharacterized class of substituted phenols for the nitroarene dioxygenases; seven previously uncharacterized substrates were evaluated for wild-type DDO, and four novel monooxygenase-like products were found for the DDO variants V350F and V350M (methoxyhydroquinone, methylhydroquinone, 2-hydroxybenzyl alcohol, and 3-nitrocatechol).
Saturation Mutagenesis of Toluene
ortho
-Monooxygenase of
Burkholderia cepacia
G4 for Enhanced 1-Naphthol Synthesis and Chloroform Degradation
Authors: Rui Lingyun , Kwon Young Man , Fishman Ayelet , Reardon Kenneth F. , Wood Thomas K.
Published: June 2004

Directed evolution of toluene
ortho
-monooxygenase (TOM) of
Burkholderia cepacia
G4 previously created the hydroxylase α-subunit (TomA3) V106A variant (TOM-Green) with increased activity for both trichloroethylene degradation (twofold enhancement) and naphthalene oxidation (six-times-higher activity). In the present study, saturation mutagenesis was performed at position A106 with
Escherichia coli
TG1/pBS(Kan)TOMV106A to improve TOM activity for both chloroform degradation and naphthalene oxidation. Whole cells expressing the A106E variant had two times better naphthalene-to-1-naphthol activity than the wild-type cells (
V
max
of 9.3 versus 4.5 nmol · min
−1
 · mg of protein
−1
and unchanged

K
m

), and the regiospecificity of the A106E variant was unchanged, with 98% 1-naphthol formed, as was confirmed with high-pressure liquid chromatography. The A106E variant degrades its natural substrate toluene 63% faster than wild-type TOM does (2.12 ± 0.07 versus 1.30 ± 0.06 nmol · min
−1
 · mg of protein
−1
[mean ± standard deviation]) at 91 μM and has a substantial decrease in regiospecificity, since
o
-cresol (50%),
m
-cresol (25%), and
p
-cresol (25%) are formed, in contrast to the 98%
o
-cresol formed by wild-type TOM. The A106E variant also has an elevated expression level compared to that of wild-type TOM, as evidenced by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Another variant, the A106F variant, has 2.8-times-better chloroform degradation activity based on gas chromatography (
V
max
of 2.61 versus 0.95 nmol · min
−1
 · mg of protein
−1
and unchanged

K
m

) and chloride release (0.034 ± 0.002 versus 0.012 ± 0.001 nmol · min
−1
 · mg of protein
−1
). The A106F variant also was expressed at levels similar to those of wild-type TOM and 62%-better toluene oxidation activity than wild-type TOM (2.11 ± 0.3 versus 1.30 ± 0.06 nmol · min
−1
 · mg of protein
−1
). A shift in regiospecificity of toluene hydroxylation was also observed for the A106F variant, with
o
-cresol (28%),
m
-cresol (18%), and
p
-cresol (54%) being formed. Statistical analysis was used to estimate that 292 colonies must be screened for a 99% probability that all 64 codons were sampled during saturation mutagenesis.
Localization and Functional Analysis of PepI, the Immunity Peptide of Pep5-Producing
Staphylococcus epidermidis
Strain 5
Authors: Hoffmann Anja , Schneider Tanja , Pag Ulrike , Sahl Hans-Georg
Published: June 2004

Pep5 is a cationic pore-forming lantibiotic produced by
Staphylococcus epidermidis
strain 5. The producer strain protects itself from the lethal action of its own bacteriocin through the 69-amino-acid immunity peptide PepI. The N-terminal segment of PepI contains a 20-amino-acid stretch of apolar residues, whereas the C terminus is very hydrophilic, with a net positive charge. We used green fluorescent protein (GFP)-PepI fusions to obtain information on its localization in vivo. PepI was found to occur outside the cytoplasm and to accumulate at the membrane-cell wall interface. The extracellular localization appeared essential for conferring immunity. We analyzed the functional role of the specific segments by constructing various mutant peptides, which were also fused to GFP. When the hydrophobic N-terminal segment of PepI was disrupted by introducing charged amino acids, the export of PepI was blocked and clones expressing such mutant peptides were Pep5 sensitive. When PepI was successively shortened at the C terminus, in contrast, its export properties remained unchanged whereas its ability to confer immunity was gradually reduced. The results show that the N-terminal part is required for the transport of PepI and that the C-terminal part is important for conferring the immunity phenotype. A concept based on target shielding is proposed for the PepI immunity mechanism.
Cloning, Nucleotide Sequence, and Overexpression of the
l
-Rhamnose Isomerase Gene from
Pseudomonas stutzeri
in
Escherichia coli
Authors: Leang Khim , Takada Goro , Ishimura Akihiro , Okita Masashi , Izumori Ken
Published: June 2004

The gene encoding
l
-rhamnose isomerase (
l
-RhI) from
Pseudomonas stutzeri
was cloned into
Escherichia coli
and sequenced. A sequence analysis of the DNA responsible for the
l
-RhI gene revealed an open reading frame of 1,290 bp coding for a protein of 430 amino acid residues with a predicted molecular mass of 46,946 Da. A comparison of the deduced amino acid sequence with sequences in relevant databases indicated that no significant homology has previously been identified. An amino acid sequence alignment, however, suggested that the residues involved in the active site of
l
-RhI from
E. coli
are conserved in that from
P. stutzeri
. The
l
-RhI gene was then overexpressed in
E. coli
cells under the control of the T5 promoter. The recombinant clone,
E. coli
JM109, produced significant levels of
l
-RhI activity, with a specific activity of 140 U/mg and a volumetric yield of 20,000 U of soluble enzyme per liter of medium. This reflected a 20-fold increase in the volumetric yield compared to the value for the intrinsic yield. The recombinant
l
-RhI protein was purified to apparent homogeneity on the basis of three-step chromatography. The purified recombinant enzyme showed a single band with an estimated molecular weight of 42,000 in a sodium dodecyl sulfate-polyacrylamide gel. The overall enzymatic properties of the purified recombinant
l
-RhI protein were the same as those of the authentic one, as the optimal activity was measured at 60°C within a broad pH range from 5.0 to 11.0, with an optimum at pH 9.0.
Enzyme Production-Based Approach for Determining the Functions of Microorganisms within a Community
Authors: Nakamura Kohei , Haruta Shin , Nguyen Huong Lan , Ishii Masaharu , Igarashi Yasuo
Published: June 2004

The functions of specific microorganisms in a microbial community were investigated during the composting process.
Cerasibacillus quisquiliarum
strain BLx
T
and
Bacillus thermoamylovorans
strain BTa were isolated and characterized in our previous studies based on their dominance in the composting system. Strain BLx
T
degrades gelatin, while strain BTa degrades starch. We hypothesized that these strains play roles in gelatinase and amylase production, respectively. The relationship between changes in the abundance ratios of each strain and those of each enzyme activity during the composting process was examined to address this hypothesis. The increase in gelatinase activity in the compost followed a dramatic increase in the abundance ratio of strain BLx
T
. Zymograph analysis demonstrated that the pattern of active gelatinase bands from strain BLx
T
was similar to that from the compost. Gelatinases from both BLx
T
and compost were partially purified and compared. Homologous N-terminal amino acid sequences were found in one of the gelatinases from strain BLx
T
and that of compost. These results indicate strain BLx
T
produces gelatinases during the composting process. Meanwhile, the increase in the abundance ratio of strain BTa was not concurrent with that of amylase activity in the compost. Moreover, the amylase activity pattern of strain BTa on the zymogram was different from that of the compost sample. These results imply that strain BTa may not produce amylases during the composting process. To our knowledge, this is the first report demonstrating that the function of a specific microorganism is directly linked to a function in the community, as determined by culture-independent and enzyme-level approaches.
Genome Organization and Localization of the
pufLM
Genes of the Photosynthesis Reaction Center in Phylogenetically Diverse Marine
Alphaproteobacteria
Authors: Pradella Silke , Allgaier Martin , Hoch Christa , Päuker Orsola , Stackebrandt Erko , Wagner-Döbler Irene
Published: June 2004

Genome organization, plasmid content and localization of the
pufLM
genes of the photosynthesis reaction center were studied by pulsed-field gel electrophoresis (PFGE) in marine phototrophic
Alphaproteobacteria
. Both anaerobic phototrophs (
Rhodobacter veldkampii
and
Rhodobacter sphaeroides
) and strictly aerobic anoxygenic phototrophs from the
Roseobacter
-
Sulfitobacter
-
Silicibacter
clade (
Roseivivax halodurans
,
Roseobacter litoralis
,
Staleya guttiformis
,
Roseovarius tolerans
, and five new strains isolated from dinoflagellate cultures) were investigated. The complete genome size was estimated for
R. litoralis
DSM6996
T
to be 4,704 kb, including three linear plasmids. All strains contained extrachromosomal elements of various conformations (linear or circular) and lengths (between 4.35 and 368 kb). In strain DFL-12, a member of a putative new genus isolated from a culture of the toxic dinoflagellate
Prorocentrum lima
, seven linear plasmids were found, together comprising 860 kb of genetic information. Hybridization with probes against the
pufLM
genes of the photosynthesis gene cluster after Southern transfer of the genomic DNAs showed these genes to be located on a linear plasmid of 91 kb in
R. litoralis
and on a linear plasmid of 120 kb in
S. guttiformis
, theoretically allowing their horizontal transfer. In all other strains, the
pufLM
genes were detected on the bacterial chromosome. The large number and significant size of the linear plasmids found especially in isolates from dinoflagellates might account for the metabolic versatility and presumed symbiotic association with eukaryotic hosts in these bacteria.