bluuebunny/crossref_metadata_2025 huggingface dataset:
Validity and reliability study of the Tilburg Pregnancy Distress Scale into Turkish
Authors: Çapik A. , Pasinlioglu T.
Published: April 2015

Accessible summary

Several instruments have been developed for the assessment of distress (stress, anxiety, depression) in pregnancy. The Tilburg Pregnancy Distress Scale (TPDS) is a useful instrument for the evaluation of distress in pregnant women.

There are no validated instruments for the evaluation of distress in pregnant women in the Turkish language.

The reliability and validity of the Turkish version of the TPDS demonstrated good comprehensibility, internal consistency and validity, and is an adequate and useful instrument for the evaluation of distress in Turkish pregnant women.

TPDS enables to practitioners determine distress in pregnant women in the early periods by practitioners. Assessment of distress levels of pregnant women constitutes an important area for both midwives and mental health nursing.

This study was conducted to adapt the Tilburg Pregnancy Distress Scale (TPDS) into Turkish and test its validity and reliability. The study was conducted in six Family Health Center regions in the province of Kars between 20 February and 10 April 2013. A total of 275 pregnant women, who met the study criteria and agreed to participate in the study, constituted the sample group of the study. For validity and reliability analysis of the scale, content validity analysis, explanatory and confirmatory factor analysis, and Cronbach's alpha coefficient were used. It was found that the two‐factor structure of the scale was valid and its fit indices were appropriate. The total Cronbach's alpha coefficient of the scale was 0.83. The cut‐off point of the scale was specified as 28 for its total score. As a consequence, the adaptation of the TPDS into Turkish was determined to be a valid and reliable measurement instrument. Assessment of distress levels of pregnant women constitutes an important area for both midwives and mental health nursing.
The effects of sodium oxybate on core body and skin temperature regulation in narcolepsy
Authors: van der Heide Astrid , Donjacour Claire E. H. M. , Pijl Hanno , Reijntjes Robert H. A. M. , Overeem Sebastiaan , Lammers Gert J. , Van Someren Eus J. W. , Fronczek Rolf
Published: April 2015

Patients suffering from narcolepsy type 1 show altered skin temperatures, resembling the profile that is related to sleep onset in healthy controls. The aim of the present study is to investigate the effects of sodium oxybate, a widely used drug to treat narcolepsy, on the 24‐h profiles of temperature and sleep‐wakefulness in patients with narcolepsy and controls. Eight hypocretin‐deficient male narcolepsy type 1 patients and eight healthy matched controls underwent temperature measurement of core body and proximal and distal skin twice, and the sleep–wake state for 24 h. After the baseline assessment, 2 × 3 g of sodium oxybate was administered for 5 nights, immediately followed by the second assessment. At baseline, daytime core body temperature and proximal skin temperature were significantly lower in patients with narcolepsy (core: 36.8 ± 0.05 °C versus 37.0 ± 0.05 °C, F = 8.31, P = 0.01; proximal: 33.4 ± 0.26 °C versus 34.3 ± 0.26 °C, F = 5.66, P = 0.03). In patients, sodium oxybate administration increased proximal skin temperature during the day (F = 6.46, P = 0.04) to a level similar as in controls, but did not affect core body temperature, distal temperature or distal–proximal temperature gradient. Sodium oxybate administration normalised the predictive value of distal skin temperature and distal–proximal temperature gradient for the onset of daytime naps (P < 0.01). In conclusion, sodium oxybate administration resulted in a partial normalisation of the skin temperature profile, by increasing daytime proximal skin temperature, and by strengthening the known relationship between skin temperature and daytime sleep propensity. These changes seem to be related to the clinical improvement induced by sodium oxybate treatment. A causal relationship is not proven.
Diversifying mechanisms in the on‐farm evolution of crop mixtures
Authors: Thomas Mathieu , Thépot Stéphanie , Galic Nathalie , Jouanne‐Pin Sophie , Remoué Carine , Goldringer Isabelle
Published: April 2015

While modern agriculture relies on genetic homogeneity, diversifying practices associated with seed exchange and seed recycling may allow crops to adapt to their environment. This socio‐genetic model is an original experimental evolution design referred to as on‐farm dynamic management of crop diversity. Investigating such model can help in understanding how evolutionary mechanisms shape crop diversity submitted to diverse agro‐environments. We studied a French farmer‐led initiative where a mixture of four wheat landraces called ‘Mélange de Touselles’ (MDT) was created and circulated within a farmers' network. The 15 sampled MDT subpopulations were simultaneously submitted to diverse environments (e.g. altitude, rainfall) and diverse farmers' practices (e.g. field size, sowing and harvesting date). Twenty‐one space‐time samples of 80 individuals each were genotyped using 17 microsatellite markers and characterized for their heading date in a ‘common‐garden’ experiment. Gene polymorphism was studied using four markers located in earliness genes. An original network‐based approach was developed to depict the particular and complex genetic structure of the landraces composing the mixture. Rapid differentiation among populations within the mixture was detected, larger at the phenotypic and gene levels than at the neutral genetic level, indicating potential divergent selection. We identified two interacting selection processes: variation in the mixture component frequencies, and evolution of within‐variety diversity, that shaped the standing variability available within the mixture. These results confirmed that diversifying practices and environments maintain genetic diversity and allow for crop evolution in the context of global change. Including concrete measurements of farmers' practices is critical to disentangle crop evolution processes.
Cognitive and affective functions of aged subacute myelo‐optico neuropathy patients in Japan
Authors: Kawahara Yuko , Deguchi Kentaro , Hishikawa Nozomi , Kurata Tomoko , Sato Kota , Kono Syoichiro , Omote Yoshio , Ohta Yasuyuki , Yamashita Toru , Abe Koji
Published: April 2015

Background

Subacute myelo‐optico neuropathy was the first epidemic drug intoxication that affected many people in Japan in the 1970s.

Aim

More than 40 years later, we assessed the real conditions of subacute myelo‐optico neuropathy patients.

Methods

The present study examined current cognitive and affective functions, activities of daily living, and vascular endothelial function in aged subacute myelo‐optico neuropathy patients (n = 28) compared with age‐, sex‐, body mass index‐ and years of schooling‐matched normal controls (n = 141).

Results

Mini‐Mental State Examination, Hasegawa Dementia Scale‐Revised, Montreal Cognitive Assessment and Frontal Assessment Battery scores were not significantly lower in subacute myelo‐optico neuropathy patients, but the Geriatric Depression Scale was significantly higher without apathy. Computerized touch‐panel tests showed poor performance in the flipping cards game, arranging pictures game and beating devils game, whereas activities of daily living and vascular endothelial function were within normal limits.

Conclusion

The present study shows that subacute myelo‐optico neuropathy patients showed essentially normal cognitive function using standard cognitive assessments, although the touch‐panel tests detected some decline in subacute myelo‐optico neuropathy patients. Subacute myelo‐optico neuropathy patients presented a higher depression score without evident apathy, activities of daily living decline or vascular endothelial dysfunction.
Improvement in generalized myasthenia gravis after continuous positive airway pressure therapy for obstructive sleep apnea: A case report
Authors: Komatsu Teppei , Onda Asako , Iguchi Yasuyuki , Hirai Toshiaki , Mitsumura Hidetaka , Kono Yu
Published: April 2015

We report a case of generalized myasthenia gravis with obstructive sleep apnea in which myasthenia gravis symptoms improved dramatically after initiation of continuous positive airway pressure therapy. A 42‐year‐old man was admitted with generalized myasthenia gravis. He was found to snore loudly during sleep and was diagnosed with obstructive sleep apnea by polysomnography. Continuous positive airway pressure therapy contributed to immediate improvements in not only the apnea–hypopnea index (70.6–20.9), but also the myasthenia gravis‐specific activities of daily living scale (10–1) and quantitative myasthenia gravis scale (21–8). We suggest that when a myasthenia gravis patient is obese and suspected to have sleep problems, examinations to detect obstructive sleep apnea should be carried out. If obstructive sleep apnea is diagnosed, continuous positive airway pressure therapy might also improve the patient's myasthenia gravis.
Relative contributions of offspring quality and environmental quality to adult field performance
Authors: Lange Rolanda , Marshall Dustin J.
Published: April 2015

Determinants of adult performance, such as growth and survival, are influenced by extrinsic, environmental and intrinsic, phenotypic factors. The relative importance of extrinsic and intrinsic factors, while ecologically relevant, is rarely estimated simultaneously. We estimate the relative contributions of offspring size (intrinsic) and various environmental factors (extrinsic) on adult performance in the marine colonial bryozoan Watersipora subtorquata. We used a variance partitioning approach for both new and previously published data, enabling us to examine the performance of over 1000 individuals in the field. We found offspring size to explain relatively little variation in adult performance. Of the environmental factors taken to account, temporal variation and an environmental gradient had the strongest influences.
Elevated light levels in schools have a protective effect on myopia
Authors: Hua Wen‐Juan , Jin Ju‐Xiang , Wu Xiao‐Yan , Yang Ji‐Wen , Jiang Xuan , Gao Guo‐Peng , Tao Fang‐Biao
Published: April 2015

Purpose

To determine whether elevated light levels in classrooms in rural areas can protect school‐age children from myopia onset or myopia progression.

Methods

A total of 317 subjects from 1713 eligible students aged six to 14 in four schools located in northeast China participated in the study. Students received a comprehensive eye examination including cycloplegic refraction and ocular biometry, which included axial length (AL), anterior chamber depth (ACD), and corneal curvature (CC) measurement, and completed a questionnaire. The intervention arm included 178 students in two schools with rebuilt elevated lighting systems and the control arm included 139 students in which lighting systems were unchanged. Results for the two arms were compared with a Wilcoxon rank sum test, a chi‐squared test or a t‐test, as appropriate. Factors that might help explain any differences were explored with multivariate linear regression analysis.

Results

The median average illuminance of blackboards and desks and uniformity of desk lighting were significantly improved, however, the uniformity of blackboard lighting declined after intervention. At baseline, the mean refraction, AL, CC, ACD and myopia prevalence between the two arms were not significantly different. After 1 year, compared with the control arm the intervention arm had a lower incidence of new myopia onset (4% vs 10%; p = 0.029), a smaller decrease in refractive error among no myopic subjects (−0.25 dioptre [D] vs −0.47 D; p = 0.001), and shorter axial growth for both non‐myopic (0.13 vs 0.18 mm; p = 0.023) and myopic subjects (0.20 vs 0.27 mm; p = 0.0001). Multivariate linear regression analysis showed the intervention program, lower hyperopic baseline refraction, lower father's education level, longer time sleeping and less time in screen‐viewing activities were associated with less refractive shift in the direction of myopia in non‐myopic children. For myopic subjects, myopia progression was significantly associated with family income only. The intervention program and older age had a protective effect on axial growth for both myopic and non‐myopic subjects. The father's education level and sleep duration were significantly associated with axial growth in non‐myopic children.

Conclusions

Elevated light levels in classrooms have a significant effect on myopia onset, decreases in refraction, and axial growth; if the findings of lighting intervention are reproduced in future studies, the ambient light levels in schools should be improved.
Exploring Variation in theMoroccan‐Dutch Collective Narrative: An Intersectional Approach
Authors: Prins Jacomijne , Polletta Francesca , van Stekelenburg Jacquelien , Klandermans Bert
Published: April 2015

Collective identities are constructed and negotiated in interaction. The dynamics of collective identity construction in the interactions of group members, however, remain understudied. Taking into consideration public discourses of ethnicity and religion in theNetherlands, in this article we explore the uses of narrative in intragroup identity construction amongMoroccan‐Dutch young adults. In line with theories of intersectionality, we expected intragroup identity construction to be influenced by the specific location of participants in a matrix of intersecting identity categories. Narratives were elicited in focus groups that varied by gender and by the educational level of the participants. We compared the content and import of stories in each group. We found that participants across groups told similar stories in which they referred to the treatment of their group at a societal level. However, we also found that the intersection of ethnicity, gender, and level of educational attainment influenced the way our participants narrated their everyday experiences, and, in particular, their relations with native Dutch neighbors, fellow students, and coworkers. An intersectional analysis shows how, faced with negative stereotypes regarding their ethnic and religious background,Moroccan‐Dutch young adults variously accept, reject, and act in relation to those stereotypes.
Challenges of Postconflict Coexistence: Narrating Truth and Justice in a Bosnian Town
Authors: Mannergren Selimovic Johanna
Published: April 2015

This article sets out to deepen our understanding of how people make everyday strategies for living together after mass atrocities and what role transitional justice may play for these strategies. Based on a study in the small town ofFoča inBosnia‐Herzegovina, the analysis unpacks the encounter between three clusters of narratives that make competing moral claims and offer different ways of ordering the past, present, and future: the “institutional” narrative formed globally at various institutions of transitional justice and here represented in the local by the International Criminal Tribunal for FormerYugoslavia (ICTY); the collective narratives of ethnonationalism constructed by entrepreneurs in politics and media and fed into daily discourses; and individual narratives “in the margins” that refuse collective categorizations. The article argues that theICTYnarrative, based on individual justice and factual truth, was, contrary to its aims, used to enforce exclusionist and collective claims. At the same time, less dominant narratives embraced theICTYnarrative, which suggests that the tribunal may potentially play a constructive role as an “archive for the future.”
Taking Matters into Their Own Hands: Presidents' Personality Traits and the Use of Executive Orders
Authors: Gallagher Maryann E. , Blackstone Bethany
Published: April 2015

Existing studies of executive orders tend to focus on two issues: how the frequency of executive orders has changed over time and whether the nature of presidential power has changed such that we should reconsider Neustadt's thesis that bargaining is the essence of presidential power. Although institutionalists bemoan the literature's focus on the “personal presidency,” no study of unilateral uses of power has taken into account the systematic influence of presidents' personalities. Instead, studies that consider why some presidents issue more executive orders than others focus on contextual factors, not attributes of the presidents. In this article we address this gap in the literature by examining whether presidents' personality traits significantly influence their propensity to issue executive orders. The results of our analysis demonstrate that both personality and institutional factors play a significant role in presidents' decisions to act unilaterally.
Restricting Membership: Assessing Agency Compliance and the Effects of Banning Federal Lobbyists from Executive Branch Advisory Committee Service
Authors: Straus Jacob R. , Ginsberg Wendy R. , Mullan Amanda K. , Petruzzelli Jaclyn D.
Published: April 2015

In October 2011, the Office of Management and Budget (OMB) issued guidelines prohibiting lobbyists from federal advisory committee service. Issued as a corollary to Executive Order 13490—which placed limits on lobbyist's government service—OMB's guidelines suggest that lobbyists have had undue influence over policy making. This article explores limited advisory committee literature and examines lobbyists' potential advisory process influence. Using data on lobbyists who served on advisory committees between 2009 and 2012, the article finds that while lobbyists' service has declined, some continue to serve. To conclude, the article explores first‐hand accounts from former advisory committee members to offer some perceived consequences of restricting lobbyist committee service.
Pharmacologic Treatment of Common Symptoms in Dialysis Patients: A Narrative Review
Authors: Moledina Dennis G. , Perry Wilson Francis
Published: April 2015

End‐stage renal disease (ESRD) patients receiving hemodialysis experience a heavy burden of disease‐related symptoms, which lead to reduced quality of life. This review focuses on aspects of ESRD‐related pharmacokinetics and on efficacy of drugs for treatment of somatic symptoms. Fatigue, pruritus, insomnia, and cramps are the most common symptoms in ESRD, and studies suggest that they are often undertreated. However, few evidence‐based guidelines exist to guide therapy in patients received dialysis. In the context of this review, we examine the role of l‐Carnitine in the treatment of fatigue and cramps; human growth hormone analog Norditropin and anabolic steroid Nandrolone for the treatment of fatigue; Gabapentin and other agents for the management of pruritis; Vitamin and creatine supplementation in the management of dialysis‐associated cramps, and somnambulates in the treatment of dialysis‐related insomnia. Treatment decisions should be made in consultation with patients with a full accounting of the potential risks and benefits of these therapies.
Intraperitoneal Immunization with Cry1Ac Protoxin from Bacillus thuringiensis Provokes Upregulation of Fc‐Gamma‐II/and Fc‐Gamma‐III Receptors Associated with IgG in the Intestinal Epithelium of Mice
Authors: Moreno‐Fierros L. , Verdín‐Terán S. L. , García‐Hernández A. L.
Published: April 2015

In humans, intestinal epithelial FcRn is expressed throughout life and mediates the bidirectional transport of IgG, but in mice, it is markedly expressed in neonatal intestine. In adults, its expression is only faintly upregulated after intestinal IgG induction such as that elicited by i.p. immunization with Cry1Ac protoxin (pCry1Ac) Bacillus thuringiensis. This led us to suggest that additional Fcγ receptors (Fcγ‐R) may be participating in epithelial IgG uptake. So, first we determined whether CD16/32 [an epitope shared by Fcγ‐RII (CD32) and Fcγ‐RIII (CD16)] was expressed in the intestinal epithelia of mice. Using confocal microscopy and flow cytometry, we detected co‐localization of IgG and CD16/32 in epithelial cells, whose frequency was increased by immunization with pCry1Ac. Western blot and cross‐immunoprecipitation results with anti‐CD16/32 and IgG antibodies in epithelial cell extracts suggested that epithelial cells bear both Fcγ‐RII and Fcγ‐RIII and contained IgG associated with Fcγ‐RII/RIII. Using anti‐CD32 and anti‐CD16 antibodies, we confirmed by Western blot, confocal microscopy and flow cytometry that both Fcγ‐RII and Fcγ‐RIII were expressed and suggested that upregulation occurred upon immunization in intestinal epithelia. Finally, we examined the in vitro effect of anti‐CD16/32, anti‐CD16 and anti‐CD32 antibodies on IgG uptake and transport by intestinal epithelial cells and found that it was partially reduced. Although further studies are still required, our results suggest that Fcγ‐RII and Fcγ‐RIII might participate in the uptake and/or transport of IgG through the intestinal epithelia of adult mice.
Variance Estimation under Two‐Phase Sampling
Authors: Saegusa Takumi
Published: April 2015

We consider the variance estimation of the weighted likelihood estimator (WLE) under two‐phase stratified sampling without replacement. Asymptotic variance of the WLE in many semiparametric models contains unknown functions or does not have a closed form. The standard method of the inverse probability weighted (IPW) sample variances of an estimated influence function is then not available in these models. To address this issue, we develop the variance estimation procedure for the WLE in a general semiparametric model. The phase I variance is estimated by taking a numerical derivative of the IPW log likelihood. The phase II variance is estimated based on the bootstrap for a stratified sample in a finite population. Despite a theoretical difficulty of dependent observations due to sampling without replacement, we establish the (bootstrap) consistency of our estimators. Finite sample properties of our method are illustrated in a simulation study.
The MYB96–HHP module integrates cold and abscisic acid signaling to activate the CBF–COR pathway in Arabidopsis
Authors: Lee Hong Gil , Seo Pil Joon
Published: April 2015

Various environmental stresses limit plant growth, development, and reproductive success. Plants have therefore evolved sophisticated adaptive responses to deal with environmental challenges. The responses of plants to environmental stresses are mainly mediated by abscisic acid (ABA)‐dependent and ABA‐independent signaling pathways. While these two pathways have been implicated to play discrete roles in abiotic stress responses, accumulating evidence suggests that they are also intertwined. Here, we report that an R2R3‐type MYB transcription factor, MYB96, integrates the ABA and cold signaling pathways. In addition to its role in ABA‐mediated drought responses, MYB96 is also induced by cold stress in an ABA‐independent manner and subsequently activates freezing tolerance. Notably, MYB96 regulates HEPTAHELICAL PROTEIN (HHP) genes by binding to their promoters. The HHP proteins, in turn, interact with C‐REPEAT BINDING FACTOR (CBF) upstream regulators, such as INDUCER OF CBF EXPRESSION 1 (ICE1), ICE2, and CALMODULIN‐BINDING TRANSCRIPTION ACTIVATOR 3 (CAMTA3). The specific interactive networks of HHPs with the CBF upstream regulators are necessary to facilitate transcriptional activation of the CBF regulon under stressful conditions. Together, the MYB96–HHP module integrates ABA‐dependent and ABA‐independent signals and activates the CBF pathway, ensuring plant adaptation to a wide range of adverse environmental fluctuations.
Ultraviolet C light pathogen inactivation treatment of platelet concentrates preserves integrin activation but affects thrombus formation kinetics on collagen in vitro
Authors: Van Aelst Britt , Devloo Rosalie , Vandekerckhove Philippe , Compernolle Veerle , Feys Hendrik B.
Published: April 2015

BACKGROUND

Ultraviolet (UV) light illumination in the presence of exogenously added photosensitizers has been used to inactivate pathogens in platelet (PLT) concentrates for some time. The THERAFLEX UV‐C system, however, illuminates PLT concentrates with UV‐C light without additional photoactive compounds. In this study residual PLT function is measured in a comprehensive paired analysis of UV‐C–treated, gamma‐irradiated, and untreated control PLT concentrates.

STUDY DESIGN AND METHODS: A pool‐and‐split design was used with buffy coat–derived PLT concentrates in 65% SSP+ additive solution. Thrombus formation kinetics in microfluidic flow chambers onto immobilized collagen was investigated with real‐time video microscopy. PLT aggregation, membrane markers, and cellular metabolism were determined concurrently.

RESULTS

Compared to gamma‐treated and untreated controls, UV‐C treatment significantly affected thrombus formation rates on Days 5 and 7, not Day 2. PLT degranulation (P‐selectin) and PLT apoptosis (annexin V binding) was slightly but significantly increased from Day 2 on. UV‐C treatment moreover induced integrin αIIbβ3 conformational changes reminiscent of activation. However, subsequent integrin activation by either PAR1‐activating hexapeptide (PAR1AP) or convulxin was unaffected. This was confirmed by PLT aggregation studies induced with collagen, PAR1AP, and ristocetin at two different agonist concentrations. Finally, UV‐C slightly increased lactic acid production rates, resulting in significantly decreased pH on Days 5 and 7, but never dropped below 7.2.

CONCLUSION

UV‐C pathogen inactivation treatment slightly but significantly increases PLT activation markers but does not profoundly influence activatability nor aggregation. The treatment does, however, attenuate thrombus formation kinetics in vitro in microfluidic flow chambers, especially after storage.
Interface Effects Between a Moving Supersonic Blade Cascade and a Downstream Diffuser Cascade
Authors: Fabri Jean , Reboux Jean , Hirsinger Francis
Published: April 2015

Theoretical and experimental research conducted on a rotating supersonic blade cascade shows that absolute and relative velocities at rotor outlet are functions of the rotating cascade and the downstream diffuser cascade geometry, independently of the inlet mass flow rate. The radial maldistribution of the flow that results from this property of supersonic blade cascades is analyzed.
Propulsion System for Research VTOL Transports
Authors: Gertsma L. W. , Zigan Steve
Published: April 2015

In anticipation of an eventual VTOL requirement for civil aviation, NASA has been conducting studies directed toward determining and developing the technology required for a commercial VTOL transport. In this paper, the commercial transport configurations are briefly reviewed; the propulsion system specifications and components developed by the engine study contractor are presented and described; and methods for using the lift-propulsion system for aircraft attitude control are discussed.
Aerodynamic Study of a Turbine Designed for a Small Low-Cost Turbofan Engine
Authors: Kofskey M. G. , Nusbaum W. J.
Published: April 2015

A 20.32 centimeter (8.00 in.) mean diameter two-stage turbine was experimentally investigated over a range of speeds from 0 to 110 percent of equivalent design speed and over a range of pressure ratios from 2.2 to 4.2. The principal results indicated that the performance level was substantially higher than that assumed in the design. As part of the program to reduce manufacturing costs, the first stage blading was reduced in thickness for ease in coining. Tests of the modified blades indicated that the aerodynamic performance of a stator or rotor blade with a large amount of reaction was affected very little by a significant change of the pressure surface.
Prediction of Flow Outlet Angle in Blade Rows With Conical Stream Surfaces
Authors: Traupel W.
Published: April 2015

Turbine stages for large volume flows, which simultaneously operate with a considerable change in density, are geometrically designed in such a way that the flow is necessarily associated with pronounced radial movement. Under such conditions the methods used hitherto for prediction of the flow outlet angle from blade rows are not dependable. The present paper deals with this problem theoretically, assuming rotational symmetry and conical flow surfaces. It is found that rotation of the blading influences the process, i.e., a row of rotating blading has rather different deflection properties than a geometrically congruent stationary row.
Transient Analysis of Ceramic Vanes for Heavy Duty Gas Turbines
Authors: Schaller R. T. , Rahaim T. J.
Published: April 2015

A transient analysis of thermal stresses in ceramic stationary vanes is presented. The application of ceramics to gas turbines represents an alternate approach for designers to increase operating temperatures. Highly dense silicon carbide and silicon nitride vanes are analyzed for application in a heavy duty gas turbine. The most severe thermal loading condition for this turbine is imposed on the vanes. The purpose of this paper is to present the effect of ceramic material, vane size, air foil, cross-sectional geometry, and gas inlet temperature on the thermal response of ceramic vanes.
The Low Emission Gas Turbine Passenger Car: What Does the Future Hold?
Authors: Nagey T. F. , Mykolenko P. , Naylor M. E. , Verkemp F. J.
Published: April 2015

This paper reviews the potential of the gas turbine as a low emission engine for passenger cars. State-of-the-art emission levels for turbines are identified together with the causes for the typically high levels of NOx that are encountered. Laboratory solutions for reduced NOx are discussed and some of the recent GM accomplishments defined. Fundamental design criteria for low emission combustors are identified. The paper concludes with a brief discussion of the problems remaining in the area of combustors for which solutions must be found before the gas turbine engine can be considered for general use.
Vibration Monitoring and Diagnostic Instrumentation for Industrial and Marine Gas Turbines
Authors: Maddox Vern
Published: April 2015

The application of vibration monitoring and diagnostic instrumentation to industrial and marine gas turbines requires some important special considerations. An initially important consideration is the proper selection and location of vibration transducers. Next, a full-time monitoring system must be selected to afford the machine complete protection against failures caused by excessive vibration. And finally, diagnostic instruments must be selected on the basis of required data for malfunction diagnosis, past machine performance history, and current operating conditions of the machine. There are a number of vibration instrument considerations peculiar to gas turbines in general, as opposed to other types of rotating machinery such as steam turbines, compressors, gears, etc. These considerations can be classified as: (a) temperature extremes, (b) environmental extremes, (c) machine casing flexibility, or stiffness, as compared to the rotor. Both the heavy-duty industrial type and the lightweight, or aircraft derivative, type of gas turbine are widely used. A distinction will not be made between these types since most special considerations apply equally well to all gas turbines.
Modified Jet Engine Application for Industrial Drives in the Libyan Desert
Authors: Greenberg D. A. , Bohannan W. R.
Published: April 2015

Gas turbines utilizing modified aircraft jet engines are successfully providing shaft power for three vital services in oil production operations in the Libyan Sahara Desert. Each of three trains of high-pressure compressors in gas injection service is powered by twin jet engines exhausting to a double-flow double-ended expansion turbine. Packaged single jet engine/expander combinations are the drivers for two low-pressure gas compressor trains in the LPG plants and for three electric generators. The remote location placed heavy emphasis on reliability and ease of maintenance in the selection of this equipment. This machinery has demonstrated its ability to perform satisfactorily under the punishing conditions required by these operations.
Operating Experience With 3-MW Gas Turbines Running on Crude Oil
Authors: Rittener D. G.
Published: April 2015

This paper gives an account of the two years’ experience with the gas turbines running on desalted crude taken from the Sarir-Tobruk pipeline in Libya. It also describes the difficulties encountered in the primary stages of operation and the changes made to eliminate them.
The Control System for the U.S. Coast Guard Icebreaker Propulsion Plant
Authors: Johnson F. W. , Stasiowski Charles
Published: April 2015

The initial portion of this paper is devoted to the control system-prime mover interface. The results of the transient simulation are reviewed with special emphasis given to their influence on the control system design. Speed and pitch control is described from the five control stations: Engineering control console, bridge console, bridge wings (2) and aloft conning station. Prime mover (3) operation in free route and icebreaking is described with special attention focused on transfer between modes and between prime movers. The data logging and alarm monitoring system are described in relation to its performance and maintenance capabilities.
Advanced Control Program for Army Gas Turbine Engines
Authors: White A. H. , Wills D. F.
Published: April 2015

This paper summarizes the results of a 30-month program of design, fabrication, and test of an advanced electronic engine control system for small (2 to 5-lb/sec airflow) turboshaft engines. The objective of the program was to develop engine control system technology which would be implemented in future systems to meet advanced engine requirements and to alleviate many of the problems experienced with past and present control systems.
Controllable Pitch Propellers With Gas Turbine Prime Movers
Authors: Ridley D. E. , Norton J. A.
Published: April 2015

The paper is concerned with the transient performance of gas turbine/controllable pitch propeller ships propulsion plants in the decelerating mode with headway on the vessel. Conventional propeller coefficients are examined, and their deficiencies for this purpose noted, particularly with regard to preliminary predictions of performance in the initial ship design phase. A tentative set of revised coefficients is proposed, and the predictions compared to two sets of full-scale data.
Model Test of Axial Flow Compressor With Variable Stators for Blast Furnace
Authors: Yamane Takeshi
Published: April 2015

In order to increase the working range and the maximum weight flow of electric motor driven axial flow compressors with variable stators at each stage for use in blast furnace application, a model unit of the compressor with two-stage variable stator having a relatively small hub-tip ratio was constructed and tested, and its performance characteristics with variable speeds and variable stators were measured and compared with the predicted performance. The tests were carried out up to the peripheral velocity of 1070 fps and stator setting angles of from 20 to −20 deg from design. The tests generally showed the results expected, but surge had risen much earlier than predicted, and the performance near the hub was not satisfactory.
Wall slip of polydisperse linear polymers using double reptation
Authors: Ebrahimi Marzieh , Ansari Mahmoud , Hatzikiriakos Savvas G.
Published: April 2015

The slip behavior of several high-density polyethylenes (HDPEs) is studied as a function of molecular weight (MW) and its distribution for a broad range of MW distributions. The slip velocity increases with decrease of MW, which is the case for several other linear polymers including monodisperse polybutadienes (PBDs), polystyrenes (PSs), and polylactides reported in the literature. For such polymers, the slip velocity, Vs, scales with weight or number average MW (due to monodispersity) as VS∝Mwβ, where β is about −2 for PBDs and −3.2 for PSs. For polydisperse HDPEs concepts from double reptation theory is used to develop an expression to relate slip velocity with MW and its distribution. Moreover, the slip velocity of linear polymers scales nonlinearly with the wall shear stress, namely, VS∝σWm. Using de Gennes' theory for slip, the values of m reported in the literature are explained on a theoretical basis and they are found to be equal to 1/n, where n is the local slope of the flow curve of the corresponding polymer, n≡ log(σw)/ log(γ̇w), which changes from 1 (Newtonian flow regime) to a constant value in the power-law flow regime.
Unraveling structures of protection ligands on gold nanoparticle Au
68
(SH)
32
Authors: Xu Wen Wu , Gao Yi , Zeng Xiao Cheng
Published: April 2015

A divide and protect approach to unraveling the atomic structure of a thiolate-protected gold nanoparticle.
Big science is hard but worth it
Authors: Turner Michael S.
Published: April 2015

Big science is hard. It is the throw-deep approach that pushes technology to the edge to achieve stunning breakthroughs that dramatically extend the frontiers of science, while inspiring the next generation of scientists and capturing the imagination of the public. The Large Hadron Collider (LHC) produced the Higgs boson, a particle that explains why all other particles have mass and whose name is now known around the world; the Atacama Large Millimeter and Submillimeter Array (ALMA) revealed some of the earliest galaxies, as well as a nearby planetary system that has a striking resemblance to our own; and for 25 years, the Hubble Space Telescope has dazzled us with its discoveries and iconic astronomical images. But before they became famous for discoveries, these and other big projects were infamous for their problems. What are the challenges for big science, and what does it take to succeed?
Hard evidence
Forensics: The Anatomy of Crime
Wellcome Collection, London. 26 February to 21 June 2015. http://wellcomecollection.org/forensics
Authors: Robinson Andrew
Published: April 2015

Exploring the origins and evolution of forensic science.
Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications
Authors: Somera Alexandre F. , Lima Adriel M. , dos Santos-Neto Álvaro J. , Lanças Fernando M. , Bacci Maurício
Published: April 2015

Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete
Leucoagaricus
gongylophorus
. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter
Atta
bisphaerica
fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by
L
.
gongylophorus
, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology.
Systematic Analysis of White Pox Disease in Acropora palmata of the Florida Keys and Role of Serratia marcescens
Authors: Joyner Jessica L. , Sutherland Kathryn P. , Kemp Dustin W. , Berry Brett , Griffin Ashton , Porter James W. , Amador Molly H. B. , Noren Hunter K. G. , Lipp Erin K.
Published: April 2015

White pox disease (WPD) affects the threatened elkhorn coral,
Acropora palmata
. Owing in part to the lack of a rapid and simple diagnostic test, there have been few systematic assessments of the prevalence of acroporid serratiosis (caused specifically by
Serratia marcescens
) versus general WPD signs. Six reefs in the Florida Keys were surveyed between 2011 and 2013 to determine the disease status of
A. palmata
and the prevalence of
S. marcescens
. WPD was noted at four of the six reefs, with WPD lesions found on 8 to 40% of the colonies surveyed.
S. marcescens
was detected in 26.9% (7/26) of the WPD lesions and in mucus from apparently healthy colonies both during and outside of disease events (9%; 18/201).
S. marcescens
was detected with greater frequency in
A. palmata
than in the overlying water column, regardless of disease status (
P
= 0.0177).
S. marcescens
could not be cultured from
A. palmata
but was isolated from healthy colonies of other coral species and was identified as pathogenic pulsed-field gel electrophoresis type PDR60. WPD lesions were frequently observed on the reef, but unlike in prior outbreaks, no whole-colony death was observed. Pathogenic
S. marcescens
was circulating on the reef but did not appear to be the primary pathogen in these recent WPD episodes, suggesting that other pathogens or stressors may contribute to signs of WPD. Results highlight the critical importance of diagnostics in coral disease investigations, especially given that field manifestation of disease may be similar, regardless of the etiological agent.
Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains
Authors: Zeng Ximin , Ardeshna Devarshi , Lin Jun
Published: April 2015

Campylobacter jejuni
, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on
C. jejuni
conjugation efficiency and the underlying mechanisms were examined. With a modified
Escherichia coli
donor strain, different
C. jejuni
recipient strains displayed significant variation in conjugation efficiency ranging from 6.2 × 10
−8
to 6.0 × 10
−3
CFU per recipient cell. Despite reduced viability, heat shock of standard
C. jejuni
NCTC 11168 and 81-176 strains (e.g., 48 to 54°C for 30 to 60 min) could dramatically enhance
C. jejuni
conjugation efficiency up to 1,000-fold. The phenotype of the heat shock-enhanced conjugation in
C. jejuni
recipient cells could be sustained for at least 9 h. Filtered supernatant from the heat shock-treated
C. jejuni
cells could not enhance conjugation efficiency, which suggests that the enhanced conjugation efficiency is independent of secreted substances. Mutagenesis analysis indicated that the clustered regularly interspaced short palindromic repeats system and the selected restriction-modification systems (Cj0030/Cj0031, Cj0139/Cj0140, Cj0690c, and HsdR) were dispensable for heat shock-enhanced conjugation in
C. jejuni
. Taking all results together, this study demonstrated a heat shock-enhanced conjugation efficiency in standard
C. jejuni
strains, leading to an optimized conjugation protocol for molecular manipulation of this organism. The findings from this study also represent a significant step toward elucidation of the molecular mechanism of conjugative gene transfer in
C. jejuni
.
Comparative Genotypic and Phenotypic Analysis of Cronobacter Species Cultured from Four Powdered Infant Formula Production Facilities: Indication of Pathoadaptation along the Food Chain
Authors: Yan Qiongqiong , Wang Juan , Gangiredla Jayanthi , Cao Yu , Martins Marta , Gopinath Gopal R. , Stephan Roger , Lampel Keith , Tall Ben D. , Fanning Séamus
Published: April 2015

Cronobacter
species are opportunistic pathogens commonly found in the environment. Among the seven
Cronobacter
species,
Cronobacter sakazakii
sequence type 4 (ST-4) is predominantly associated with recorded cases of infantile meningitis. This study reports on a 26-month powdered infant formula (PIF) surveillance program in four production facilities located in distinct geographic regions. The objective was to identify the ST(s) in PIF production environments and to investigate the phenotypic features that support their survival. Of all 168
Cronobacter
isolates, 133 were recovered from a PIF production environment, 31 were of clinical origin, and 4 were laboratory type strains. Sequence type 1 (
n
= 84 isolates; 63.9%) was the dominant type in PIF production environments. The majority of these isolates clustered with an indistinguishable pulsotype and persisted for at least an 18-month period. Moreover, DNA microarray results identified two phylogenetic lineages among ST-4 strains tested. Thereafter, the ST-1 and -4 isolates were phenotypically compared. Differences were noted based on the phenotypes expressed by these isolates. The ST-1 PIF isolates produced stronger biofilms at both 28°C and 37°C, while the ST-4 clinical isolates exhibited greater swimming activity and increased binding to Congo red dye. Given the fact that PIF is a low-moisture environment and that the clinical environment provides for an interaction between the pathogen and its host, these differences may be consistent with a form of pathoadaptation. These findings help to extend our current understanding of the epidemiology and ecology of
Cronobacter
species in PIF production environments.
Highly Active and Specific Tyrosine Ammonia-Lyases from Diverse Origins Enable Enhanced Production of Aromatic Compounds in Bacteria and Saccharomyces cerevisiae
Authors: Jendresen Christian Bille , Stahlhut Steen Gustav , Li Mingji , Gaspar Paula , Siedler Solvej , Förster Jochen , Maury Jérôme , Borodina Irina , Nielsen Alex Toftgaard
Published: April 2015

Phenylalanine and tyrosine ammonia-lyases form cinnamic acid and
p
-coumaric acid, which are precursors of a wide range of aromatic compounds of biotechnological interest. Lack of highly active and specific tyrosine ammonia-lyases has previously been a limitation in metabolic engineering approaches. We therefore identified 22 sequences
in silico
using synteny information and aiming for sequence divergence. We performed a comparative
in vivo
study, expressing the genes intracellularly in bacteria and yeast. When produced heterologously, some enzymes resulted in significantly higher production of
p
-coumaric acid in several different industrially important production organisms. Three novel enzymes were found to have activity exclusively for phenylalanine, including an enzyme from the low-GC Gram-positive bacterium
Brevibacillus laterosporus
, a bacterial-type enzyme from the amoeba
Dictyostelium discoideum
, and a phenylalanine ammonia-lyase from the moss
Physcomitrella patens
(producing 230 μM cinnamic acid per unit of optical density at 600 nm [OD
600
]) in the medium using
Escherichia coli
as the heterologous host). Novel tyrosine ammonia-lyases having higher reported substrate specificity than previously characterized enzymes were also identified. Enzymes from
Herpetosiphon aurantiacus
and
Flavobacterium johnsoniae
resulted in high production of
p
-coumaric acid in
Escherichia coli
(producing 440 μM
p
-coumaric acid OD
600
unit
−1
in the medium) and in
Lactococcus lactis
. The enzymes were also efficient in
Saccharomyces cerevisiae
, where
p
-coumaric acid accumulation was improved 5-fold over that in strains expressing previously characterized tyrosine ammonia-lyases.