bluuebunny/crossref_metadata_2025 huggingface dataset:
Nursing as a caring practice from a phenomenological perspective
Authors: Spichiger Elisabeth , Wallhagen Margaret I. , Benner Patricia
Published: November 2005

Nursing is frequently described as a caring practice. What this concept means may be less clear. This paper considers nursing as a caring practice in three steps. First, the concept of practice based on Taylor's and MacIntyre's philosophical definitions of the term is described. Secondly, numerous notions of caring are presented; the call from some nurse researchers for quantification of the concept and why this is problematic is discussed; and an exposition of caring from a phenomenological perspective is provided. Finally, the notions of practice and caring are joined, and the concept of a caring practice is presented. Nursing as a public caring practice is illustrated with examples from an interpretive phenomenological study. In conclusion, it is claimed that a phenomenological view of caring combined with a comprehensive definition of practice is well suited to nursing, and allows for a description of nurses’ caring practices from both a nursing and patient perspective.
Co‐sleeping as a window into Swedish culture: considerations of gender and health care
Authors: Welles‐Nystrom Barbara
Published: November 2005

The purpose of this study is to examine the Swedish practice of co‐sleeping and relate it to the cultural discourse on the gendered family and health. The Swedish study, part of the International Study of Parents, Children and Schools, focuses on some Western parents’ ideas about health, child development, child‐rearing goals and parental practices. It also addressed specific questions regarding parents’ theories about the nature, gender and frequency of co‐sleeping in Swedish families. Quantitative and qualitative data were collected with five cohorts of parents and their 60 children who ranged in age from 6 months to 8 years. The sample was balanced for sex and birth order. Parents completed batteries of standardized questionnaires and they were interviewed about their beliefs and practices related to child rearing and child development. A questionnaire about co‐sleeping was sent post hoc to the families. The results showed that Swedish children often co‐sleep with both their parents until school age, when more boys than girls cease the practice. This is an important finding, because much of the literature suggests that this practice exists primarily for infants in non‐Western cultures who co‐sleep with their mothers. Co‐sleeping in Sweden is perceived as a normal family activity, which differed from the other societies studied. Thus, the study of practice has important methodological implications. When a family practice is studied, carefully documented and understood in its many dimensions, it provides a window into the culture in which the practice is embedded and may explain how gender relates to the practice. For health‐care professionals who encounter families from diverse cultural backgrounds, this methodological approach illustrates how parenting practices relate to health‐care issues.
Not letting the disease get the upper hand over life: strategies of teens with asthma
Authors: Rydström Ingela , Hartman Jan , Segesten Kerstin
Published: November 2005

Adolescence is a period when teens normally revolt against being dependent. For teens with asthma this period may be even more difficult to deal with, as they also have to deal with their illness. Since few studies describe this phenomenon, the aim of this study was to provide a theoretical understanding of how teens with asthma manage their everyday life in relation to their disease. A grounded theory research design, according to Glaser, was used to uncover the phenomenon. The study was undertaken at a camp for teenagers with asthma during the summer of 2003. Twelve girls and 11 boys with moderate to severe asthma participated in the study. Participant observations and interviews were used, and the first author collected the data and participated in the activities. The findings reveal a theoretical model which shows that teens’ core concern is not to let the disease get the upper hand over life. To manage this core concern the teens were found to use three strategies: keeping a distance to the disease, challenging the disease and taking the disease into consideration. Boys mainly kept a distance to the disease while girls mainly kept the disease into consideration. Challenging the disease seemed to be a strategy used by both girls and boys. The teens’ strategies were not studied close to their everyday life, but a conclusion drawn from our study was that the provisional theory in many respects can be transferred to their everyday life, even though further research is needed to develop this provisional theory in other settings.
Factors related to long‐duration pain and sick leave among Swedish staff working in the public health service
Authors: Nilsson Annika , Sjödén Per‐Olow , Dahl JoAnne , Denison Eva
Published: November 2005

The aim of the present study was to provide information about factors related to long‐duration pain (LDP) (>3 months), sick leave (SL) and long sick leave (LSL) (>3 months) among staff in the community health services. The specific research question was: To what extent do data on activity, physical function, pain severity, psychological/cognitive factors, expectations of LDP, expectations to be working within 6 months and work satisfaction predict LDP, SL and LSL respectively? Logistic regression analyses were used to test predicted membership in the groups LDP, SL and LSL. In this context prediction refers to statistical prediction only, due to the cross‐sectional design. Staff (n = 914) in the public health services in a medium‐sized Swedish city completed a questionnaire during the spring of 2000. The results show that musculoskeletal pain and SL for this occupational group are common. Pain severity, expectations of LDP and fear‐avoidance increased the odds of being in the LDP group, while kinesiophobia decreased the odds. Pain severity and kinesiophobia increased the odds of being in the SL group, while expectations to be working in 6 months decreased the odds. Only expectations to be working in 6 months predicted membership in the LSL group, decreasing the odds. Although some caution is warranted concerning the representativity of the sample, the results indicate that expectations about pain duration and ability to work are important psychosocial factors in LDP and LSL.
Accuracy and concordance of nurses in emergency department triage
Authors: Göransson Katarina , Ehrenberg Anna , Marklund Bertil , Ehnfors Margareta
Published: November 2005

In the emergency department (ED) Registered Nurses (RNs) often perform triage, i.e. the sorting and prioritizing of patients. The allocation of acuity ratings is commonly based on a triage scale. To date, three reliable 5‐level triage scales exist, of which the Canadian Triage and Acuity Scale (CTAS) is one. In Sweden, few studies on ED triage have been conducted and the organization of triage has been found to vary considerably with no common triage scale. The aim of this study was to investigate the accuracy and concordance of emergency nurses acuity ratings of patient scenarios in the ED setting. Totally, 423 RNs from 48 (62%) Swedish EDs each triaged 18 patient scenarios using the CTAS. Of the 7550 triage ratings, 57.6% were triaged in concordance with the expected outcome and no scenario was triaged into the same triage level by all RNs. Inter‐rater agreement for all RNs was κ = 0.46 (unweighted) and κ = 0.71 (weighted). The fact that the κ‐values are only moderate to good and the low concordance between the RNs call for further studies, especially from a patient safety perspective.
EFFECT OF NUTRIENT DEPRIVATION AND RESUPPLY ON METABOLITES AND ENZYMES RELATED TO CARBON ALLOCATION IN GRACILARIA TENUISTIPITATA (RHODOPHYTA)1
Authors: Collén Pi Nyvall , Camitz Astrid , Hancock Robert D. , Viola Roberto , Pedersén Marianne
Published: November 2005

The starch content of red algae normally increases during nitrogen limitation. Based on this we hypothesized that nutrient deprivation would result in an increased activity of starch‐synthesizing enzymes and a decrease in the activity of starch‐degrading enzymes, with the opposite scenario when nutrients were sufficient. We therefore examined the effect of the nutrient status of Gracilaria tenuistipitata Chang et Xia on the content of starch and floridoside and on the activity of enzymes involved in the allocation of carbon into starch, floridoside, and agar; floridoside phosphate synthase and α‐galactosidase involved in synthesis and degradation of floridoside; starch synthase and starch phosphorylase involved in the metabolism of starch; uridine 5′‐diphosphate (UDP)‐glucose pyrophosphorylase; adenosine 5′‐diphosphate‐glucose pyrophosphorylase; UDP‐glucose 4‐epimerase; and phosphoglucomutase. During the period of nutrient limitation the starch and floridoside content increased, as did dry weight and C/N ratio, whereas growth rate and protein content decreased. A general decrease in the enzyme activities during nutrient limitation was also observed, indicating a decrease in overall cellular metabolism. The addition of nutrients caused an increase in enzyme activities and a decrease in the contents of starch and floridoside. Of the enzymes examined, only the activity of UDP‐glucose pyrophosphorylase increased during nutrient limitation and decreased abruptly after nutrient addition. This implies a regulatory role for this enzyme in the supply of UDP‐glucose for starch synthesis. It also supports our suggestion that UDP‐glucose is the substrate for starch synthesis in red algae. This assertion is further strengthened by the observation that of the potential starch synthases only the UDP‐glucose starch synthase could support the observed rate of starch synthesis.
PURIFICATION AND CHARACTERIZATION OF THE 20S PROTEASOME FROM THEALGA CHARA CORALLINA (CHAROPHYCEAE)1
Authors: Moriyasu Yuji , Malek Ladislav
Published: November 2005

We purified the 20S proteasome from the alga Chara corallina Willd with DEAE–ion‐exchange column chromatography and preparative nondenaturing PAGE. The analysis of the purified enzyme bynondenaturing PAGE gave a single band whose molecular mass was estimated to be about 600,000 Da by gel permeation chromatography and whose isoelectric point was at pH 5.5. Two‐dimensional gel electrophoresis gave at least 12 spots with molecular masses from 26,000 to 32,000 Da in a wide range of isoelectric points. The 20S proteasome hydrolyzed three types of artificial substrates used to differentiate chymotrypsin‐like, trypsin‐like, and peptidyl glutamyl peptidase activities. Both the chymotrypsin‐like and the peptidyl glutamyl peptidase activities were enhanced by SDS. In the presence of 0.03% SDS, the optimal pH for both activities was 8.5. Trypsin‐like activity of the 20S proteasome had a broad pH optimum in an alkaline region and was not activated but inhibited by SDS. Its chymotrypsin‐like activity was inhibited by N‐ethylmaleimide, p‐chloromercuribenzoic acid, and chymostatin. In contrast, its peptidyl glutamyl peptidase activity was not inhibited by chymostatin. Moreover, proteasome inhibitors MG 115 and MG 135 were effective against the chymotrypsin‐like activity and less so against the peptidyl glutamyl peptidase activity. These properties were very similar to those of the proteasomes of mammalian, yeast, and spinach cells. The large size of Chara cells will make in vivo manipulations and investigations of the proteasome proteolytic system possible.
EFFECTS OF POTASSIUM ON THE PHOTOSYNTHETIC RECOVERY OF THE TERRESTRIAL CYANOBACTERIUM, NOSTOC FLAGELLIFORME (CYANOPHYCEAE) DURING REHYDRATION1
Authors: Qiu Baosheng , Zhang Aihong , Zhou Wenbin , Wei Jiamian , Dong Hui , Liu Zhili
Published: November 2005

Effects of potassium on the photosynthetic recovery of Nostoc flagelliforme (Berk. & Curtis) Bornet & Flahault were investigated to determine its exact role during rehydration. Potassium enhanced recovery of the ability to reduce the primary quinone‐type acceptor (QA) and plastoquinone (PQ) pool and the area over the fluorescence rise curve was increased by 127%. The proportions of closed PSII reaction centers at phases J and I and the net rate of closure of PSII reaction centers were decreased by, respectively, 19%, 8%, and 23% with the addition of potassium, due to changes in the ability of PSII for multiple turnovers needed to reduce the PQ pool. Potassium significantly enhanced the probability of electron transfer beyond QA and the recovery of electron transport flux per PSII reaction center. Electron transport from water to methyl viologen for samples rehydrated in K+‐free BG11 medium was 54% of those with the addition of potassium. However, electron flow from water to p‐benzoquinone and from reduced 2,6‐dichlorophenol‐indophenol to methyl viologen showed little change with the addition of potassium. The fast phase and slow phase of millisecond delayed light emission and the ATP content for samples rehydrated in K+‐free BG11 medium were, respectively, 71.6%, 50.7%, and 77.1% of those with the addition of potassium. These suggested that potassium affected electron transfer from PQ to plastocyanin through the cytochrome b6f complex and the proton motive force across the thylakoid membranes, probably reflecting its role in charge balance during H+ transport by the cytochrome b6f complex.
RECRUITMENT OF BENTHIC MICROCYSTIS (CYANOPHYCEAE) TO THE WATER COLUMN: INTERNAL BUOYANCY CHANGES OR RESUSPENSION?1
Authors: Verspagen Jolanda M.H. , Snelder Eveline O. F. M. , Visser Petra M. , Huisman Jef , Mur Luuc R. , Ibelings Bas W.
Published: November 2005

In some lakes, large amounts of the potentially toxic cyanobacterium Microcystis overwinter in the sediment. This overwintering population might inoculate the water column in spring and promote the development of dense surface blooms of Microcystis during summer. In the Dutch Lake Volkerak, we found photochemically active Microcystis colonies in the sediment throughout the year. The most vital colonies originated from shallow sediments within the euphotic zone. We investigated whether recruitment of Microcystis colonies from the sediment to the water column was an active process, through production of gas vesicles or respiration of carbohydrate ballast. We calculated net buoyancy, as an indication of relative density, using the amounts and densities of the major cell constituents (carbohydrates, proteins, and gas vesicles). Carbohydrate content of benthic Microcystis cells was very low throughout the year. Buoyancy changes of benthic Microcystis were mostly a result of changes in gas vesicle volume. Before the summer bloom, net buoyancy and the amount of buoyant colonies in the sediment did not change. Therefore, recruitment of Microcystis from the sediment does not seem to be an active process regulated by internal buoyancy changes. Instead, our observations indicate that attachment of sediment particles to colonies plays an important part in the buoyancy state of benthic colonies. Therefore, we suggest that recruitment of Microcystis is more likely a passive process resulting from resuspension by wind‐induced mixing or bioturbation. Consequently, shallow areas of the lake probably play a more important role in recruitment of benthic Microcystis than deep areas.
CD14+ cell collection in non‐cytokine‐stimulated donors with the COM.TEC cell separator
Authors: Strasser Erwin F. , Hendelmeier Martin , Weisbach Volker , Zimmermann Robert , Ringwald Jürgen , Juntke Ronald , Sauer Gudrun , Zingsem Jürgen , Eckstein Reinhold
Published: November 2005

BACKGROUND: The COM.TEC cell separator (Fresenius Hemocare), equipped with the MNC program (single‐stage chamber) and the PBSC‐LYM program (dual‐stage chamber), was evaluated for CD14+ cell collection regarding cell yields, collection efficiencies (CEs), and the content of residual cells in harvests.

STUDY DESIGN AND METHODS: Twenty‐four non‐cytokine‐stimulated donors underwent 5‐L mononuclear cell (MNC) collections on the COM.TEC device to compare both programs. Two software versions (v02.03.05 vs. v03.00.04) were investigated for optimization of the CD14+ cell collection process. Blood counts of donors and products were analyzed for CD14+ cells by flow cytometry and for platelets (PLTs), white blood cells, and red blood cells (RBCs) by a blood cell counter.

RESULTS: In 5‐L collections, the MNC program resulted in high CEs (83 ± 23%) and yields (1.2 × 109 ± 0.6 × 109 per unit) of CD14+ cells, but the products showed high residual PLTs. The use of a dual‐stage chamber in the PBSC‐LYM program produced a low content of residual PLTs (0.7 × 1011 ± 0.3 × 1011 per unit) and RBCs but failed to reach a target of 1 × 109 CD14+ cells. Modulated light to stabilize the buffy‐coat detection by the interface monitor significantly improved CD14+ cell enrichment. By use of the PBSC‐LYM program, higher centrifuge velocity (1700 rpm [382 × g] vs. 1500 rpm [297 × g]) improved significantly CD14+ cell yields (0.7 × 109 vs. 0.5 × 109 cells).

CONCLUSION: A pure CD14+ cell product with low numbers of residual cells was obtained by the PBSC‐LYM program, which could be useful for good manufacturing practice–conformed production within closed systems. The MNC program offers the collection of high CD14+ cell yields with excellent CEs but also high residual PLT counts.
Fast element mapping of titanium wear around implants of different surface structures
Authors: Meyer Ulrich , Bühner Martin , Büchter Andre , Kruse‐Lösler Birgit , Stamm Thomas , Wiesmann Hans Peter
Published: November 2005

Abstract: The effect of unintended titanium release around oral implants remains a biological concern. The current study was undertaken to evaluate a new detection system of element mapping in biological probes. A new scanning electron microscopy‐energy dispersive spectroscopy detection method was used to map the features of titanium contamination in peri‐implant bone around implants with different surface structures. The amount of titanium wear was highest adjacent to titanium‐plasma‐sprayed surfaces, followed by sandblastered large grid acid‐etched and smooth surfaces. A high sensitivity of titanium detection over large areas of bone tissue was observed. A high spatial resolution of titanium wear particles (20 nm) could be reached and correlated to the ultrastructural morphological features of peri‐implant tissue. Cells adjacent to titanium wear revealed no signs of morphological alterations on a nanoscale level at early periods of implant/bone interaction. The new technique may serve as a fast and effective tool to evaluate titanium release effects in biological probes.
Comparisons of bacterial patterns present at implant and tooth sites in subjects on supportive periodontal therapy
Authors: Agerbaek Mette R. , Lang Niklaus P. , Persson G. Rutger
Published: November 2005

Objective: (I) To compare the oral microflora at implant and tooth sites in subjects participating in a periodontal recall program, (II) to test whether the microflora at implant and tooth sites differ as an effect of gingival bleeding (bleeding on probing (BOP)), or pocket probing depth (PPD), and (III) to test whether smoking and gender had an impact on the microflora.

Material and methods: Data were collected from 127 implants and all teeth in 56 subjects. Microbiological data were identified by the DNA–DNA checkerboard hybridization.

Results: PPD≥4 mm were found in 16.9% of tooth, and at 26.6% of implant sites (P<0.01). Tooth sites with PPD≥4 mm had a 3.1‐fold higher bacterial load than implant sites (mean difference: 66%, 95% confidence interval (CI): 40.7–91.3, P<0.001). No differences were found for the red, orange, green, and yellow complexes. A higher total bacterial load was found at implant sites with PPD≥4 mm (mean difference 35.7 × 105, 95% CI: 5.2 (105) to 66.1 (105), P<0.02 with equal variance not assumed). At implant sites, BOP had no impact on bacterial load but influenced the load at tooth sites (P<0.01).

Conclusion: BOP, and smoking had no impact on bacteria at implant sites but influenced the bacterial load at tooth sites. Tooth sites harbored more bacteria than implant sites with comparable PPD. The 4 mm PPD cutoff level influenced the distribution and amounts of bacterial loads. The subject factor is explanatory to bacterial load at both tooth and implant sites.
Prevalence of Psychiatric Illness in Women in an Oncology Sexual Health Population: A Retrospective Pilot Study
Authors: Amsterdam Alison , Carter Jeanne , Krychman Michael
Published: November 2005

Introduction

Oncology patients often present to healthcare providers with a history of pre-existing psychiatric conditions. Associated treatments are well known to impact sexual functioning. The identification of these confounding conditions and medications is an integral part of the comprehensive management of sexual dysfunction in oncology patients.

Aim

To report the prevalence of psychiatric diagnoses and agents in an oncology sexual health clinic.

Methods

A retrospective review was performed using 204 sequential charts of patients who attended the Sexual Health Program at Memorial Sloan-Kettering Cancer Center from March 2003 through August 2004.

Main Outcome Measures

All patients were evaluated by a sexual medicine gynecologist and received an extensive medical history, psychosexual assessment, and a focused gynecologic examination.

Results

Fourteen patients (7%) did not have cancer and were excluded from further analysis. Of the remaining 190 patients, the median age at initial visit was 48 years (range 22–76) and the majority of patients were menopausal (87%). The most common diagnosis was breast cancer (44%). One hundred twenty-eight patients (67%) had prior pelvic surgery and 43 (23%) had prior pelvic radiation. The most frequently encountered sexual complaints were dyspareunia (65%), vaginal dryness (63%), hypoactive desire disorder (46%), and orgasmic dysfunction (7%). At initial presentation, 52 patients (27%) reported having a prior or concurrent psychiatric diagnosis and 72 (38%) were taking an anti-depressant and/or an anxiolytic. Treatment recommendations for sexual dysfunction consisted of psychosexual counseling, psychiatric referral, vaginal moisturizers and lubricants, hormonal therapy with minimally absorbed vaginal estrogen suppositories, vaginal dilators, and/or skilled exercise.

Conclusion

Psychiatric conditions are commonly encountered in the oncology population as are the medications to treat them. Because it is well established that these medications are often implicated in sexual dysfunction, further research is needed to determine the mechanism of action within the desire pathway of the cancer patient and treatment of such disorders.
Hospitalization for oral malignancies in Western Australians: a four‐year retrospective analysis
Authors: SUBRAMANIAM Shiva , SMITH Kirrilee , KRUGER Estie , TENNANT Marc
Published: November 2005

Background:  To assess the incidence, age, sex, direct financial burden and Indigenous distribution of hospital separations for oral malignancies.

Methods:  Data for the retrospective analysis was obtained from the Western Australian Hospital Morbidity Data System for the four financial years 1999/2000 to 2002/2003. Principal diagnosis, classified by the International Classification of Disease (ICD‐10AM) system was obtained from every patient diagnosed with an oral malignancy (ICD‐10 codes: C02.0 – D37.0), and discharged from every private and public hospital in Western Australia for the study period.

Results:  The average age of hospitalization for oral malignancies is 58 years. Males are twice as likely to be hospitalized than females. Indigenous patients are 1.3 times more likely to be hospitalized for oral malignancies and stay in hospital for nearly twice as long as non‐indigenous patients. Indigenous patients had a 3.5 times higher rate of palate malignancies, and 1.4 times higher rate of tonsil malignancies than non‐Indigenous patients. Lip malignancies were most prevalent in non‐indigenous patients. Oral malignancies represent a 15.5% of the oral health related hospitalization costs but only 4.6% of separations.

Conclusion:  Oral malignancies represent a considerable financial burden to the health system compared with the percentage of patients. With increasing incidence rates, especially amongst elderly, male and indigenous population groups, the future implications for the health care system is of particular concern.
Size traits and site conditions determine changes in seed bank structure caused by grazing exclusion in semiarid annual plant communities
Authors: Osem Yagil , Perevolotsky Avi , Kigel Jaime
Published: November 2005

1. Contrasting patterns of change in the seed bank of natural grasslands are frequently found in response to grazing by domestic herbivores. Here, we studied the hypotheses that a) patterns of change in seed bank density and composition in response to grazing depend on spatial variation in resource availability and productivity, and b) that variation among species in patterns of seed bank response to grazing is linked to differences in species size traits (i.e. size of plant, dispersal unit and seed).

2. Effects of sheep grazing exclusion on the seed bank were followed during five years in a semiarid Mediterranean annual plant community in Israel. Seed bank density and composition were measured in autumn, before the rainy season, inside and outside fenced exclosures in four neighboring topographic sites differing in vegetation characteristics, soil resources and primary productivity: Wadi (dry stream terraces, high productive site), Hilltop, South‐ and North‐facing slopes (less productive sites).

3. Topographic sites differed in seed density (range ca 2500–18000 seed m−2) and in seed bank response to grazing exclusion. Fencing increased seed density by 78, 51 and 18% in the Wadi, South‐ and North‐facing slopes, respectively, but had no effect in the Hilltop. At the species level, grazing exclusion interacted with site conditions in determining species seed bank density, with larger or opposite changes in the high productive Wadi compared to the other less productive sites.

4. Changes in seed bank structure after grazing exclusion were strongly related to species size traits. Grazing exclusion favored species with large size traits in all sites, while seed density of tiny species decreased strongly in the high productive Wadi. Species with medium and small size traits showed lesser or no responses.

5. The size of plants, dispersal units and seeds were strongly correlated to each other, thus confounding the evaluation of the relative importance of each trait in the response of species to grazing and site conditions. We propose that the relative importance of plant size vs seed size in the response to grazing changes with productivity level.
A Numerical Model for Oil Film Flow in an Aeroengine Bearing Chamber and Comparison to Experimental Data
Authors: Farrall Mark , Simmons Kathy , Hibberd Stephen , Gorse Philippe
Published: November 2005

The work presented forms part of an ongoing investigation, focusing on modeling the motion of a wall oil film present in a bearing chamber and comparison to existing experimental data. The film is generated through the impingement of oil droplets shed from a roller bearing. Momentum resulting from the impact of oil droplets, interfacial shear from the airflow, and gravity cause the film to migrate around the chamber. Oil and air exit the chamber at scavenge and vent ports. A previously reported numerical approach to the simulation of steady-state two-phase flow in a bearing chamber, which includes in-house submodels for droplet-film interaction and oil film motion, has been extended. This paper includes the addition of boundary conditions for the vent and scavenge together with a comparison to experimental results obtained from ITS, University of Karlsruhe. The solution is found to be sensitive to the choice of boundary conditions applied to the vent and scavenge.
Influence of High Fogging Systems on Gas Turbine Engine Operation and Performance
Authors: Cataldi Giovanni , Güntner Harald , Matz Charles , McKay Tom , Hoffmann Jürgen , Nemet Anton , Lecheler Stefan , Braun Jost
Published: November 2005

High fogging is a power augmentation device where water is sprayed upstream of the compressor inlet with higher mass flow than that which would be needed to saturate the intake air. The main focus of this paper is on applications of high fogging on the ALSTOM gas turbine engines of the family GT24/GT26. Engine operation and performance are illustrated based on test results obtained from four different engines that have meanwhile accumulated more than 12,000 operating hours (OH) in commercial operation with ALSTOM’s ALFog® high fogging system. The effect of internal cooling (water evaporation inside the compressor) is investigated considering actual compressor boundaries matched within the complete engine. Changes in the secondary air system (SAS) and corresponding movement of the engine operating line have been taken into account. Power output gain as high as 7.1% was experimentally demonstrated for injected water mass fraction (f=mH2O∕mair) equal to 1% and considering internal cooling effects only. Higher figures can be obtained for operation at low ambient relative humidity and partial evaporation upstream of the compressor inlet.
Experimental Operating Range Extension of a Twin-Spool Turbofan Engine by Active Stability Control Measures
Authors: Scheidler Stephan G. , Fottner Leonhard
Published: November 2005

Modern engine operation is guided by the aim to broaden the operating range and to increase the stage loading allowing the stage count to be reduced. This is possible by active stability control measures to extend the available stable operating range. Different strategies of an active control system, such as air injection and air recirculation have been applied. While in the past results have been published mainly regarding the stability enhancement of compressor rigs or single-spool engines, this experimental study focuses on both the stability as well as the operating range extension of a twin-spool turbofan engine as an example of a real engine application on an aircraft. The objective of this investigation is the analysis of the engine behavior with active stabilization compared to unsupported operation. For this purpose, high-frequency pressure signals are used and analyzed to investigate the effects of air injection with respect to the instability onset progress and the development of any instabilities, such as rotating stall and surge in the low-pressure compression (LPC) system. These Kulite signals are fed to a control system. Its amplified output signals control fast acting direct-drive valves circumferentially distributed ahead of the LPC. For the application of air injection described in the paper, the air is delivered by an external source. The control system responsible for air injection is a real-time system which directly reacts on marked instabilities and their precursors. It allows the LPC System to recover from fully developed rotating stall by asymmetric air injection based on the pressure signals. Additionally, a delayed appearance of instabilities can be provoked by the system. Air injection guided by this control system resulted in a reduction of the required amount of air compared to constant air injection. Also, disturbances travelling at rotor speed can be detected, damped, and eliminated by this control system with a modulation of the injected air in such a way that the injection maximum travels around the ten injection positions.
Component Map Generation of a Gas Turbine Using Genetic Algorithms
Authors: Kong Changduk , Kho Seonghee , Ki Jayoung
Published: November 2005

In order to estimate the precise performance of the existing gas turbine engine, the component maps with more realistic performance characteristics are needed. Because the component maps are the engine manufacturer’s propriety obtained from very expensive experimental tests, they are not provided to the customers, generally. Therefore, because the engineers, who are working the performance simulation, have been mostly relying on component maps scaled from the similar existing maps, the accuracy of the performance analysis using the scaled maps may be relatively lower than that using the real component maps. Therefore, a component map generation method using experimental data and the genetic algorithms are newly proposed in this study. The engine test unit to be used for map generation has a free power turbine type small turboshaft engine. In order to generate the performance map for compressor of this engine, after obtaining engine performance data through experimental tests, and then the third order equations, which have relationships with the mass flow function, the pressure ratio, and the isentropic efficiency as to the engine rotational speed, were derived by using the genetic algorithms. A steady-state performance analysis was performed with the generated maps of the compressor by the commercial gas turbine performance analysis program GASTURB (Kurzke, 2001). In order to verify the proposed scheme, the experimental data for verification were compared with performance analysis results using traditional scaled component maps and performance analysis results using a generated compressor map by genetic algorithms (GAs). In comparison, it was found that the analysis results using the generated map by GAs were well agreed with experimental data. Therefore, it was confirmed that the component maps can be generated from the experimental data by using GAs and it may be considered that the more realistic component maps can be obtained if more various conditions and accurate sensors would be used.
Shapes of Elliptic Methane Laminar Jet Diffusion Flames
Authors: Camacho Jorge R. , Choudhuri Ahsan R.
Published: November 2005

Buoyant and nonbuoyant shapes of methane flames issued from a 2:1 aspect ratio elliptic tube burner were measured. Nonbuoyant conditions were obtained in the KC-135 microgravity research aircraft operated by NASA’s Johnson Space Center. A mathematical model based on the extended Burke-Schumann flame theory is developed to predict the flame length of an elliptic burner. The model utilizes Roper’s theoretical method for circular burners and extends the analysis for elliptic burners. The predicted flame length using the theoretical model agrees well with experimental measurements. In general for the elliptic burner the nonbuoyant flames are longer than the buoyant flames. However, measured lengths of both buoyant and nonbuoyant flame lengths change proportionally with the volumetric fuel flow rate and support the L vs Q correlation. The maximum flame width measured at buoyant and nonbuoyant conditions also show a proportional relation with the volumetric fuel flow rate. Normalized buoyant and nonbuoyant flame lengths of the elliptic burner correlate (L∕d∝Re) with the jet exit Reynolds number and exhibit a higher slope compared to a circular burner. Normalized flame width data show a power correlation (w∕d=cFrn) with the jet exit Froude number.
Structure-Guided Discovery of Novel Aminoglycoside Mimetics as Antibacterial Translation Inhibitors
Authors: Zhou Yuefen , Gregor Vlad E. , Sun Zhongxiang , Ayida Benjamin K. , Winters Geoffrey C. , Murphy Douglas , Simonsen Klaus B. , Vourloumis Dionisios , Fish Sarah , Froelich Jamie M. , Wall Daniel , Hermann Thomas
Published: November 2005

We report the structure-guided discovery, synthesis, and initial characterization of 3,5-diamino-piperidinyl triazines (DAPT), a novel translation inhibitor class that targets bacterial rRNA and exhibits broad-spectrum antibacterial activity. DAPT compounds were designed as structural mimetics of aminoglycoside antibiotics which bind to the bacterial ribosomal decoding site and thereby interfere with translational fidelity. We found that DAPT compounds bind to oligonucleotide models of decoding-site RNA, inhibit translation in vitro, and induce translation misincorporation in vivo, in agreement with a mechanism of action at the ribosomal decoding site. The novel DAPT antibacterials inhibit growth of gram-positive and gram-negative bacteria, including the respiratory pathogen
Pseudomonas aeruginosa
, and display low toxicity to human cell lines. In a mouse protection model, an advanced DAPT compound demonstrated efficacy against an
Escherichia coli
infection at a 50% protective dose of 2.4 mg/kg of body weight by single-dose intravenous administration.
DX-619, a Novel Des-Fluoro(6) Quinolone Manifesting Low Frequency of Selection of Resistant
Staphylococcus aureus
Mutants: Quinolone Resistance beyond Modification of Type II Topoisomerases
Authors: Strahilevitz Jacob , Truong-Bolduc Que Chi , Hooper David C.
Published: November 2005

DX-619, a novel des-fluoro(6) quinolone, was 16- to 32-fold, twofold, and four- to eightfold more potent than ciprofloxacin, gemifloxacin, and garenoxacin, respectively, against wild-type
Staphylococcus aureus
. DX-619 manifested equal fourfold increases in MIC against a common
parC
mutant and a common
gyrA
mutant and selected for mutants at up to two- to fourfold its MIC, consistent with dual-targeting properties. Of the four independent single-step mutants selected, two had new single mutations in
parC
(V87F and R17H), and two shared a new
gyrA
mutation (A26V), one with an additional deletion mutation in
parE
(Δ215-7). By allelic exchange, the ParC but not the GyrA or ParE mutation was shown to be fully responsible for the resistance phenotypes, suggesting an as yet undefined mechanism of resistance operating in conjunction with type II topoisomerase mutations contributed to resistance to DX-619. Studies with purified topoisomerase IV and gyrase from
S. aureus
also showed that DX-619 had similar activity against topoisomerase IV and gyrase (50% stimulation of cleavage complexes concentration, 1.25 and 0.62 to 1.25 μg/ml, respectively). Susceptibility studies with DX-619 and an array of efflux pump substrates with and without reserpine, an inhibitor of efflux pumps, suggested that resistance in DX-619-selected mutants is affected by mechanisms other than mutations in topoisomerases or known reserpine-inhibitable pumps in
S. aureus
and thus are likely novel.
β-Lactam Resistance in
Staphylococcus aureus
Cells That Do Not Require a Cell Wall for Integrity
Authors: Fuller Elizabeth , Elmer Catherine , Nattress Fiona , Ellis Richard , Horne Glenda , Cook Peter , Fawcett Tony
Published: November 2005

Staphylococcus aureus
ATCC 9144 cells with defective cell walls were generated on a medium with elevated osmolality in the presence of sublethal levels of penicillin G. On removal of antibiotic pressure, the cells exhibited stable penicillin and methicillin resistance. The resistance was homogeneous and its acquisition was enhanced following transient cell wall-defective growth. The resistant cells were
mecA
negative, β-lactamase negative and did not contain any mutations in the coding regions of
pbp
genes. When penicillin was added back to resistant cells, they continued to grow and produced a diffuse cell wall that was resistant to the action by lysostaphin but was very sensitive to lysis with Triton X-100. These data indicate that the resistant cells are not dependent upon an intact cell wall for osmotic stability and they are able to switch readily to this mode of growth in the presence of penicillin G.
Effective Antimicrobial Regimens for Use in Humans for Therapy ofBacillus anthracisInfections and Postexposure Prophylaxis
Authors: Deziel Mark R. , Heine Henry , Louie Arnold , Kao Mark , Byrne William R. , Basset Jennifer , Miller Lynda , Bush Karen , Kelly Michael , Drusano G. L.
Published: November 2005

Expanded options for treatments directed against pathogens that can be used for bioterrorism are urgently needed. Treatment regimens directed against such pathogens can be identified only by using data derived from in vitro and animal studies. It is crucial that these studies reliably predict the efficacy of proposed treatments in humans. The objective of this study was to identify a levofloxacin treatment regimen that will serve as an effective therapy forBacillus anthracisinfections and postexposure prophylaxis. An in vitro hollow-fiber infection model that replicates the pharmacokinetic profile of levofloxacin observed in humans (half-life [t1/2], 7.5 h) or in animals, such as the mouse or the rhesus monkey (t1/2, ∼2 h), was used to evaluate a proposed indication for levofloxacin (500 mg once daily) for the treatment ofBacillus anthracisinfections. The results obtained with the in vitro model served as the basis for the doses and the dose schedules that were evaluated in the mouse inhalational anthrax model. The effects of levofloxacin and ciprofloxacin treatment were compared to those of no treatment (untreated controls). The main outcome measure in the in vitro hollow-fiber infection model was a persistent reduction of culture density (≥4 log10reduction) and prevention of the emergence of levofloxacin-resistant organisms. In the mouse inhalational anthrax model the main outcome measure was survival. The results indicated that levofloxacin given once daily with simulated human pharmacokinetics effectively sterilizedBacillus anthraciscultures. By using a simulated animal pharmacokinetic profile, a once-daily dosing regimen that provided a human-equivalent exposure failed to sterilize the cultures. Dosing regimens that “partially humanized” levofloxacin exposures within the constraints of animal pharmacokinetics reproduced the antimicrobial efficacy seen with human pharmacokinetics. In a mouse inhalational anthrax model, once-daily dosing was significantly inferior (survival end point) to regimens of dosing every 12 h or every 6 h with identical total daily levofloxacin doses. These results demonstrate the predictive value of the in vitro hollow-fiber infection model with respect to the success or the failure of treatment regimens in animals. Furthermore, the model permits the evaluation of treatment regimens that “humanize” antibiotic exposures in animal models, enhancing the confidence with which animal models may be used to reliably predict the efficacies of proposed antibiotic treatments in humans in situations (e.g., the release of pathogens as agents of bioterrorism or emerging infectious diseases) where human trials cannot be performed. A treatment regimen effective in rhesus monkeys was identified.
Pitfalls in Estimating Piperaquine Elimination
Authors: Tarning Joel , Lindegårdh Niklas , Annerberg Anna , Singtoroj Thida , Day Nicholas P. J. , Ashton Michael , White Nicholas J.
Published: November 2005

By using a sensitive new assay, the terminal elimination half-life of the antimalarial piperaquine in a healthy volunteer was estimated to be 33 days, which is longer than estimated previously. This result illustrates the importance of extended sampling duration and sensitive assay methodologies in characterizing the disposition of slowly eliminated antimalarial drugs.
Attenuation of the Activity of Caspofungin at High Concentrations against
Candida albicans
: Possible Role of Cell Wall Integrity and Calcineurin Pathways
Authors: Wiederhold Nathan P. , Kontoyiannis Dimitrios P. , Prince Randall A. , Lewis Russell E.
Published: November 2005

Caspofungin had diminished activity in vitro against
Candida albicans
at concentrations of 8 to 32 μg/ml. This phenomenon was markedly attenuated in a Δ
mkc1
/Δ
mkc1
deletion mutant and by the addition of cyclosporine to the wild type. Short exposure to these caspofungin concentrations resulted in
MKC1
up-regulation, suggesting roles of cell wall integrity and calcineurin pathways.
VIM-12, a Novel Plasmid-Mediated Metallo-β-Lactamase from
Klebsiella pneumoniae
That Resembles a VIM-1/VIM-2 Hybrid
Authors: Pournaras Spyros , Ikonomidis Alexandros , Tzouvelekis Leonidas S. , Tokatlidou Despoina , Spanakis Nicholas , Maniatis Antonios N. , Legakis Nicholas J. , Tsakris Athanassios
Published: November 2005

A transferable plasmid from
Klebsiella pneumoniae
carried a class 1 integron containing
bla
VIM-12
, a novel
bla
VIM
-type gene, flanked by two copies of
aacA7. bla
VIM-12
was clustered between
bla
VIM-1
and
bla
VIM-2
and differed from
bla
VIM-1
by 18 nucleotides that were all located at the 3′ end and matched the corresponding nucleotides in
bla
VIM-2
. The
bla
VIM-12
-associated 59-base element was identical to that described in
bla
VIM-2
alleles.
Effect of Voriconazole Combined with Micafungin against
Candida
,
Aspergillus
, and
Scedosporium
spp. and
Fusarium solani
Authors: Heyn Kathrin , Tredup Antje , Salvenmoser Stefanie , Müller Frank-Michael C.
Published: November 2005

Effects of voriconazole combined with micafungin against 101 isolates of
Candida
spp. and 100 isolates of filamentous fungi have been evaluated by in vitro checkerboard analysis. The combination was indifferent for 97% of the
Candida
isolates and synergistic for 64% of the filamentous fungi (79% for
Aspergillus fumigatus
).
CONSTRUCTIVE UNIVERSAL CENTRAL LIMIT THEOREMS BASED ON INTERACTING FOCK SPACES
Authors: ACCARDI L. , CRISMALE V. , LU Y. G.
Published: November 2005

Cabana-Duvillard and lonescu11have proved that any symmetric probability measure with moments of any order can be obtained as central limit theorem of self-adjoint, weakly independent and symmetrically distributed (in a quantum souse) random variables. Results of this type will be called "universal central limit theorem".

Using Interacting Fock Space (IFS) techniques we extend this result in two directions: (i) we prove that the random variables can be taken to be generalized Gaussian in the sense of Accardi and Bożejko3and we give a realization of such random variables as sums of creation, annihilation and preservation operators acting on an appropriate IFS; (ii) we extend the above-mentioned result to the nonsymmetric case. The nontrivial difference between the symmetric and the nonsymmetric case is explained at the end of the introduction below.
A NEW IDEA TO DEFINE THE δ-FUNCTION OF AN OBSERVABLE IN THE CONTEXT OF WHITE NOISE ANALYSIS
Authors: WANG CAISHI
Published: November 2005

In this paper, we present a new idea to define the δ-function of an observable within the canonical framework of white noise analysis. We introduce a class of observables called δ-composable observables. We then define the δ-function of such an observable as the generalized operator determined uniquely by the spectral density of the observable. Surprisingly, we find that the δ-function of a δ-composable observable is always positive as a generalized operator. Finally, we show an example of a δ-composable observable and examine properties of its δ-function.
CONTROL OF OBJECT VISIBILITY IN VOLUME RENDERING — A DISTANCE-BASED APPROACH
Authors: ZHOU JIANLONG , DÖRING ANDREAS , TÖNNIES KLAUS D.
Published: November 2005

Volume data often have redundant information for clinical uses. The essence of volume rendering can be regarded as a mechanism to determine visibility of redundant information and structures of interest using different approaches. Controlling the visibility of these structures in volume rendering depends on the following factors in existing rendering algorithms: The data value of current voxel and its derivatives (used in transfer function based approaches), and the voxel position (used in volume clipping). This paper introduces the distance which is defined by the user into volume rendering pipeline to control the visibility of structures. The distance based approach, which is named as distance transfer function, has the flexibility of transfer functions for depicting data information and the advantages of volume clippings for visualizing inner structures. The results show that the distance based approach is a powerful tool for volume data information depiction.