bluuebunny/crossref_metadata_2025 huggingface dataset:
Acidified Sodium Chlorite as an Alternative to Chlorine for Elimination of Salmonella on Alfalfa Seeds
Authors: Liao C.‐H.
Published: April 2009

ABSTRACT:  The health and environmental hazard associated with the use of chlorine for food processing has been documented previously. This study was conducted to determine if acidified sodium chlorite (ASC) could be used to replace calcium hypochlorite (Ca[OCl]2) for disinfection of alfalfa seeds. Contaminated seeds containing approximately 1.5 × 107 CFU/g of Salmonella were treated with ASC or Ca(OCl)2 at different concentrations and for different periods of time. Results showed that the efficacy of ASC and Ca(OCl)2 for elimination of Salmonella on contaminated seeds could be improved greatly by extending the treatment time from the traditional 15 to 45 min. Treatment of seeds with 800 ppm of ASC for 45 min reduced the number of Salmonella by 3.9 log units, approximately 1.2 log units higher than that treated with 20000 ppm of Ca(OCl)2. Treatment of seeds with a lower concentration (100 to 400 ppm) of ASC for 45 min reduced the number of Salmonella by 1.3 to 2.2 log units. Soaking alfalfa seeds in 800 ppm of ASC for 45 min did not affect seed germination. However, soaking seeds in 20000 ppm of Ca(OCl)2 for 45 min reduced seed germination by 20%. Unlike Ca(OCl)2, antimicrobial efficiency of ASC was not affected by pre‐exposure to alfalfa seeds. Data presented also showed that Salmonella on newly inoculated seeds that had been stored at 4 °C for less than 7 d were more sensitive to sanitizer treatment than those on seeds that had been stored for 4 wk or longer.
Modeling the Effect of Marination and Temperature on Salmonella Inactivation during Drying of Beef Jerky
Authors: Yoon Yohan , Geornaras Ifigenia , Kendall Patricia A. , Sofos John N.
Published: April 2009

ABSTRACT:  This study modeled the effect of drying temperature in combination with predrying marination treatments to inactivate Salmonella on beef jerky. Beef inside round slices were inoculated with Salmonella and treated with (1) nothing (C), (2) traditional marinade (M), or (3) dipped into a 5% acetic acid solution for 10 min before exposure to M (AM). After 24 h of marination at 4 °C, samples were dehydrated at 52, 57, or 63 °C. Total counts (tryptic soy agar supplemented with 0.1% sodium pyruvate, TSAP) and Salmonella (XLD agar) were enumerated after inoculation and at 0, 2, 4, 6, 8, and 10 h during drying. For calculation of death rates (DR, log CFU/cm2/h), shoulder period (h), low asymptote, and upper asymptote, cell counts from TSAP were fitted to the Baranyi model. The DRs were then further expressed as a function of storage temperature. Inactivation occurred without an initial lag phase (shoulder period), while correlation (R2) values of fitted curves were ≥ 0.861. The DRs of C (−0.29 to −0.62) and M (−0.36 to −0.63) treatments were similar, while DRs of the AM treatment were higher (−1.22 to −1.46). The DRs were then fitted to a polynomial equation as a function of temperature. After validation, good (C and M) or acceptable (AM) model performances were observed (R2= 0.954 to 0.987; bias factors: 1.03 [C], 1.01 [M], 0.71 [AM]; accuracy factors: 1.05 [C], 1.06 [M], 1.41 [AM]). The developed models may be useful in selecting drying temperatures and times in combination with predrying treatments for adequate inactivation of Salmonella in beef jerky.
Clostridium Perfringens Growth from Spore Inocula in Sous‐Vide Processed Pork‐Based Mexican Entrée
Authors: Miguel‐Garcia Denise Y. , Juneja Vijay K. , Valenzuela‐Melendrez Martin , Díaz‐Cinco Martha E. , Thippareddi H. , Aida Peña‐Ramos E.
Published: April 2009

ABSTRACT:  The combined effect of Citricidal® wih irradiation on Clostridium perfringens growth from spores in a sous‐vide processed marinated pork meat Mexican entrée was investigated. Citricidal was added at 200 or 800 ppm after mixing pork meat with tomatillo sauce and inoculated with 3 log10 CFU/g of C. perfringens spores. Samples were irradiated at either 0 or 2 kGy, heated to an internal temperature of 71 °C, and stored at 4 °C for 28 d, 15 °C for 45 d, and 25 °C for 26 h. To simulate the conditions that may occur during transportation, distribution, storage, or handling in supermarkets or by consumers, the effect of static temperature abuse on C. perfringens growth was assessed by transferring samples stored at 4 to 25 °C for 13 and 15 h. Total C. perfringens populations were determined by plating diluted samples on tryptose‐sulfite‐cycloserine agar. Growth was not observed up to 45 d of storage at 15 °C in samples supplemented with 800 ppm of Citricidal. At 25 °C, no significant differences (P > 0.05) on the lag phase duration due to antimicrobial treatments was observed. The temperature abuse of refrigerated products for up to 15 h did not lead to C. perfringens growth to high infective dose levels of 1 million cells required to cause food poisoning. The results suggest that 800 ppm Citricidal can have significant bacteriostatic activity against C. perfringens and may provide a degree of protection against this pathogen in sous‐vide processed marinated pork meat Mexican entrée, under mild temperature abuse (≤ 15 °C) conditions.
Application of Raisin Extracts as Preservatives in Liquid Bread and Bread Systems
Authors: Wei Q. , Wolf‐Hall C. , Hall III C.A.
Published: April 2009

ABSTRACT:  Interest in natural ingredients with multifunctions in food has led to the investigation of the antimicrobial activity of raisins, a traditional baking ingredient. Water and 60% ethanol extracts, and raisin juice concentrate (RJC, a commercial food ingredient) were assessed for their ability to inhibit the growth of ropy‐bread‐causing Bacillus species. The ability of these additives and raisin paste were tested for antifungal activity in liquid bread model system and bread. In the liquid bread model, concentrations as low as 20 and 36 mg crude extract or RJC per gram media significantly (P < 0.05) reduced the populations of B. licheniformis and B. subtilis, respectively. A significant reduction in the population of Aspergillus flavus and Penicillium chrysogenum was achieved at 80 and 470 mg crude extract per gram media, respectively. Bread formulas containing 7.5% of a water extract (equivalent to 70 mg extract per gram dough) or RJC (70 mg/g dough) produced bread that had equivalent mold‐free shelf life. The mean mold‐free shelf life of the bread containing 7.5% water extract was 18.1 ± 3.3 d at room temperature while the negative control was mold free for 9.4 ± 2.4 d. The antifungal efficacy of the extracts in bread was equivalent to 0.24% calcium propionate in 21 d of storage. Doubling the concentration of the extract did not improve the mold‐retarding property in bread. The bread containing raisin paste, the percentage of which in dough was equivalent to 15% raisin extract, exhibited a stronger antifungal activity than did the extracts in bread.
Performance of Starter in Yogurt Supplemented with Soy Protein Isolate and Biotransformation of Isoflavones during Storage Period
Authors: Pham Thuy T. , Shah Nagendra P.
Published: April 2009

ABSTRACT:  In this study, soy protein isolate (SPI) (4%, v/w) was supplemented to the yogurt mix to increase the amount of biologically active isoflavone in yogurt (SY). The control yogurt was without any SPI supplementation (USY). The supplementation significantly (P < 0.05) increased the lactose metabolism by the yogurt starter including Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 (Lb 11842) and Streptococcus thermophilus ST 1342 (ST 1342) during the fermentation process by 4.7%. The starter produced more acetic acid and less lactic acid in SY than that in USY and altered the ratio of lactic and acetic acid during the entire storage period. The viability of both Lb 11842 and ST 1342 in SY was significantly (P < 0.05) lower than that in USY from 14 d of the storage period, however, their concentration still remained high (8.11 to 8.84 log CFU/g). The starter transformed 72.8% of total inactive isoflavone glycosides (IG) to active isoflavone aglycones (IA), increasing the IA content from 1.35 to 15.01 mg/100 g sample. During the storage period, IA concentration slowly rose from 15.02 to 15.51 mg/100 g sample.
Prognostic Value of Natriuretic Peptides in Chagas’ Disease: A Head‐to‐Head Comparison of the 3 Natriuretic Peptides
Authors: Moreira Maria da Consolação V. , Wang Yong , Heringer‐Walther Silvia , Wessel Niels , Walther Thomas
Published: April 2009

To determine the diagnostic and prognostic value of natriuretic peptides in patients with Chagas’ disease (CD), the authors first measured atrial (ANP), B‐type (BNP), and C‐type natriuretic peptide (CNP) and compared their diagnostic and prognostic capacity with that in other dilated cardiomyopathies (DCM). The CD and DCM patients were subdivided according to their New York Heart Association (NYHA) classification. Circulating ANP and more pronounced BNP, but not CNP, were increased in CD and DCM patients in relation to NYHA class. Importantly, ANP and BNP were already significantly elevated in CD patients without systolic ventricular dysfunction. All 3 natriuretic peptides were correlated with echocardiographic parameters in CD patients. While ANP and BNP have high predictive value for mortality and necessity for heart transplant in CD, CNP can not predict them. Thus, ANP and BNP rather than CNP could be used as valuable molecular markers to identify asymptomatic CD patients for early therapy and predict clinical outcomes.
Both the Peroxisome Proliferator‐Activated Receptor δ Agonist, GW0742, and Ezetimibe Promote Reverse Cholesterol Transport in Mice by Reducing Intestinal Reabsorption of HDL‐Derived Cholesterol
Authors: Briand François , Naik Snehal U. , Fuki Ilia , Millar John S. , Macphee Colin , Walker Max , Billheimer Jeffrey , Rothblat George , Rader Daniel J.
Published: April 2009

Peroxisome proliferator‐activated receptor δ (PPARδ) agonism increases HDL cholesterol and has therefore the potential to stimulate macrophage‐to‐feces reverse cholesterol transport (RCT). To test whether PPAR™ activation promotes RCT in mice, in vivo macrophage RCT was assessed using cholesterol‐loaded/3H‐cholesterol‐labeled macrophages injected intraperitoneally. PPAR™ agonist GW0742 (10 mg/kg per day) did not change 3H‐tracer plasma appearance, but increased fecal 3H‐free sterols excretion by 103% (p < 0.005) over 48 hours. Total free cholesterol efflux from macrophages to serum (collected from both control and GW0742 groups) was not different, although ABCA1‐mediated efflux was significantly higher with GW0742. The metabolic fate of HDL labeled with 3H‐cholesteryl ether or 3H‐cholesteryl oleate was also measured. While 3H‐cholesteryl ether tissue uptake was unchanged, the 3H‐tracer recovered in fecal free sterol fraction after 3H‐cholesteryl oleate injection increased by 88% with GW0742 (p < 0.0005). This was associated with a lower Niemann‐Pick C1 like 1 (NPC1L1) mRNA expression in the small intestine (p < 0.05). The same experiments in mice treated with ezetimibe, which blocks NPC1L1, showed a similar 2‐fold increase in fecal free sterol excretion after labeled macrophages or HDL injection. In conclusion, PPAR™ activation enhances excretion of macrophage or HDL‐derived cholesterol in feces through reduced NPC1L1 expression in mice, comparable to the effect of ezetimibe.
An Unknown Author
Authors: MAUTNER THOMAS
Published: April 2009

John Morrice (1685‐1740), about whom some biographical information is given, is here identified as the author of anonymous writings in various publications, including The Spectator and The Tatler, and of a song by Händel. Many of these writings have until now been unattributed and a few incorrectly unattributed.
Dental professionals’ knowledge about treatment of patients with spinal cord injury
Authors: Sullivan Amy L. , Morgan Christy , Bailey Jessica
Published: April 2009

This study investigated the knowledge and training of dental professionals to competently serve persons with spinal cord injuries (SCI). Fifty dental clinics were approached to complete a survey containing questions regarding their special needs training. From the 35 completed surveys, descriptive quantitative data were analyzed. The majority of professionals reported minimal exposure to special needs dentistry during their academic training. Further analysis revealed a lack of expertise in wheelchair transfers or knowledge of possible medical complications. This study suggests that additional training is needed if dental professionals are to comfortably and safely care for patients with SCI.
Effectiveness of oral self‐care among adult Gullah‐speaking African Americans with diabetes
Authors: Yuen Hon K. , Tress Mary E. , Salinas Carlos F. , Slate Elizabeth H.
Published: April 2009

We investigated the efficacy of plaque removal after an oral self‐care demonstration among adult Gullah‐speaking African Americans with diabetes. Fifty‐four adults with diabetes completed an observed, uninstructed oral self‐care demonstration with their normal mode of oral self‐care. Before and after the oral self‐care demonstration, the plaque levels of six test teeth were assessed using the Plaque Index. The mean percentage of plaque removal after the oral self‐care demonstration was 27.4%. The mandibular teeth and the lingual surface had less plaque removal compared with the maxillary teeth and buccal surfaces. Only approximately 10% of participants achieved 50% or more plaque removal after the oral self‐care demonstration. Thus, the majority of the participants did not achieve an acceptable level of plaque removal. Dental health professionals should emphasize better oral home care for people with diabetes and teach them how to access the lingual surfaces, especially of the mandibular teeth.
What Do We Do Wednesday? On Beginning the Class as University‐Specific Work: A Preliminary Study*
Authors: EGLIN PETER
Published: April 2009

Je pose la question: «Qu'en est‐il au juste des activités des universités qui en font précisément des universités?» Et je l'aborde ethnométhodologiquement d'une manière préliminaire, en examinant la réalisation interactionnelle de ce qu'est, pour les parties présentes, d'une manière observable et rapportable, le début d'un cours à l'université. Rechercher une réponse à la question, étant donné les renseignements sur cassette audio disponibles, provoque l'utilisation réfléchie par les membres des ressources contextuelles catégorielles, séquentielles et autres rendues disponibles par l'encadrement. Les questions de la signification analytique de la méthode documentaire d'interprétation et de l'abstraction des catégories d'adhésion sont brièvement reprises.

I pose the question—just what is university‐specific about the activities of universities?—and address it ethnomethodologically in a preliminary way by examining the interactional accomplishment of what is, for the parties present, observably and reportably the beginning of a class at a university. Pursuing an answer to the question, given the audiotaped data to hand, turns on members' reflexive use of the categorical, sequential, and otherwise contextual resources made available by the setting. The questions of the analytic significance of the documentary method of interpretation and of the abstractness of membership categories are briefly taken up.
Gender and Promotion at Canadian Universities*
Authors: STEWART PENNI , ORNSTEIN MICHAEL , DRAKICH JANICE
Published: April 2009

De 1984 à 1999, pour tous les professeurs à plein temps des universités canadiennes, les modèles de temps de défaillance accéléré démontrent que le temps médian de promotion de professeur adjoint à professeur agrégé est de 0,4 année plus long pour les femmes. Il n'y a pas de pic correspondant au refus de titularisation après cinq à sept ans de service, et les augmentations salariales des promotions sont stables avec le temps. Le temps médian de promotion de professeur agrégéà professeur titulaire est d'un an plus long pour les femmes que le temps médian pour les hommes, soit 8,3 années. Les différences entre les disciplines et entre les institutions n'ont qu'un petit impact sur les évaluations des différences entre les genres dans les promotions.

From 1984 to 1999, for all full‐time faculty members at Canadian universities, accelerated failure time models show that the median time to promotion from assistant to associate professor is 0.4 years longer for women. There is no peak corresponding to denial of tenure after five to seven years of service and rates of promotion are stable over time. Women's median time for promotion from associate to full professor is one year longer than the median for men, 8.3 years. Variation between disciplines and between institutions has little impact on estimates of gender differences in promotion.
A Pressure Angle Function Method for Describing Tooth Profiles of Planar Gears
Authors: Jing Lin
Published: April 2009

A general mathematical model for describing the geometries and the geometric characteristics of meshing tooth profiles of planar gears is established. The function of pressure angle in the angular displacement of gears, called the pressure angle function (PAF), is introduced to characterize this model. The different tooth profiles and their geometric properties could be generated and analyzed logically and systematically by using this model and defining various PAFs. This new method is applicable to any type of gear pairs including circular or noncircular. In addition, by using this method, it is relatively easy to realize the desired geometrical and mechanical properties into the design.
Optimization of Engine Torque Management Under Uncertainty for Vehicle Driveline Clunk Using Time-Dependent Metamodels
Authors: Wehrwein Daniel , Mourelatos Zissimos P.
Published: April 2009

Quality and performance are two important customer requirements in vehicle design. Driveline clunk negatively affects the perceived quality and must be minimized. This can be achieved using engine torque management, which is part of engine calibration. During a tip-in event, the engine torque rate of rise is limited until all the driveline lash is taken up. The engine torque rate of rise can negatively affect the vehicle throttle response, which determines performance. The engine torque management must be therefore balanced against throttle response. In practice, the engine torque rate of rise is calibrated manually. This article describes an analytical methodology for calibrating the engine torque considering uncertainty, in order to minimize clunk, while still meeting throttle response constraints. A set of predetermined engine torque profiles are considered, which span the practical range of interest. The transmission turbine speed is calculated for each profile using a bond graph vehicle model. Clunk is quantified by the magnitude of the turbine speed spike. Using the engine torque profiles and the corresponding turbine speed responses, a time-dependent metamodel is created using principal component analysis and kriging. The metamodel predicts the turbine speed response due to any engine torque profile and is used in deterministic and reliability-based optimizations to minimize clunk. Compared with commonly used production calibration, the clunk disturbance is reduced substantially without greatly affecting the vehicle throttle response.
Analysis and Design of a Spherical Micromechanism With Flexure Hinges
Authors: Callegari Massimo , Cammarata Alessandro , Gabrielli Andrea , Ruggiu Maurizio , Sinatra Rosario
Published: April 2009

The article describes the design of a robotic wrist able to perform spherical motions: Its mechanical architecture is based on parallel kinematics and is suitable to be realized at the mini- or microscale by means of flexible joints. In view of the preliminary design, a rigid-body model has been studied first and the direct and inverse kinematic analyses have been performed, allowing for the determination of theoretical workspace and passive joints’ displacements. The rigid-body dynamic behavior and the operative ranges of the machine have been assessed through the development of an inverse dynamics model. Then, the microparts have been designed with the help of finite element method (FEM) and multibody software and the study has been focused on the flexures: Since the analyses showed that the center of the spherical motion moves around several millimeters in the workspace, the original kinematic concept has been modified with the introduction of a ball joint constraining the mobile platform to frame so as to prevent unwanted translations.
A Deterministic Lagrangian-Based Global Optimization Approach for Quasiseparable Nonconvex Mixed-Integer Nonlinear Programs
Authors: Khajavirad Aida , Michalek Jeremy J.
Published: April 2009

We propose a deterministic approach for global optimization of nonconvex quasiseparable problems encountered frequently in engineering systems design. Our branch and bound-based optimization algorithm applies Lagrangian decomposition to (1) generate tight lower bounds by exploiting the structure of the problem and (2) enable parallel computing of subsystems and use of efficient dual methods. We apply the approach to two important product design applications: (1) product family optimization with a fixed-platform configuration and (2) single product design using an integrated marketing-engineering framework. Results show that Lagrangian bounds are much tighter than the factorable programming bounds implemented by the commercial global solver BARON, and the proposed lower bounding scheme shows encouraging robustness and scalability, enabling solution of some highly nonlinear problems that cause difficulty for existing solvers. The deterministic approach also provides lower bounds on the global optimum, eliminating uncertainty of solution quality inherent to popular applications of stochastic and local solvers.
Design of an Adaptive Cathodic Protection Device Powered by Four Photovoltaic Solar Panels
Authors: Kharzi S. , Haddadi M. , Malek A. , Barazane L.
Published: April 2009

Among a large number of photovoltaic applications, we are interested in the cathodic protection. It is one of the solutions used for the structures subjected to corrosion, mainly in oil and gas industries. In this work, optimum design sizing and system description are presented. Based on the design of a solar photovoltaic powered minicathodic protection system, a standard configuration of the photovoltaic system using a combination of four panels (two in series and two in parallel), has been derived. This standard size option must be matched at any cases of the cathodic protection station. For this purpose, an adaptive circuit, which is a voltage regulator with variable output, has been developed. Usually, cathodic protection systems work with constant current output, which is the necessary condition to procure immunity voltage of the structures against corrosion. The major difficulty to achieve this goal is the variations in the surrounding medium resistivity. To overcome this difficulty, several systems of control and regulation intended for cathodic protection system powered by photovoltaic energy have been designed and discussed. In our case, we propose an adaptive adjustment of the buck-boost converter output voltage by means of the microcontroller pulse width modulation output. In this paper, a complete design of the adaptive cathodic protection system using photovoltaic energy is carried out.
A Simplified Method for Calculating the Effective Solar Optical Properties of a Venetian Blind Layer for Building Energy Simulation
Authors: Kotey N. A. , Collins M. R. , Wright J. L. , Jiang T.
Published: April 2009

The use of venetian blinds to control solar gain through windows is common in both residential and commercial buildings, and their potential for reduction in peak cooling load and energy consumption is recognized to be large. As such, there is a strong need for models that allow a venetian blind to be included in glazing system analysis. A simplified method of calculating the “effective” solar optical properties of a venetian blind is presented. The solar optical properties of the entire blind are determined based on slat geometry and the optical properties of the slat material, and on the direction and nature (beam or diffuse) of incident radiation. The slat material optical properties are assumed to be independent of the angle of incidence, and are assumed to transmit and reflect beam radiation diffusely. As a first approximation, the slats are assumed to be flat with negligible thickness. A correction is then developed and applied that accounts for the curvature of the slat. The results of the flat and curved slat models are compared with experimental data for commercially available venetian blinds. Both models demonstrate excellent agreement with experiments, except when the profile and slat angles are aligned. In that case, the flat slat model predicts blind transmissions that are too large. The models developed in this study provide useful input to multilayer glazing/shading models used for rating or for building energy simulation.
Tin as a Possible Candidate for Solar Thermochemical Redox Process for Hydrogen Production
Authors: Vishnevetsky Irina , Epstein Michael
Published: April 2009

The feasibility to produce hydrogen in the Sn–H2O/SnO2–C thermochemical water splitting redox process depends mainly on the efficiency of the tin hydrolysis step, which has not been studied adequately so far, while the cassererite carboreduction is implemented by industry for tin production. The present work deals with the hydrolysis of different kinds of tin powders at different experimental conditions at moderate temperature range 180–620°C. In spite of the fact that the rate of hydrogen production is lower compared with other metals, e.g., zinc, at the same reactor temperature, high conversion level was obtained in a controllable reaction. Consequently, tin can be a relevant candidate for solar hydrogen production considering the advantage of significant lower temperatures required for the solar carboreduction of its oxide.
Design of the Heliostat Field of the CSIRO Solar Tower
Authors: Schramek Philipp , Mills David R. , Stein Wes , Le Lièvre Peter
Published: April 2009

A close-packed heliostat field of more than 800 m2 reflector area has been installed by Solar Heat and Power for the CSIRO solar tower at the Energy Centre in Newcastle, Australia. The heliostat field has been designed with significantly greater field packing density than normally associated with heliostat fields. It can be shown that even though a heliostat field with a high ground coverage exhibits more blocking and shading, a higher annual performance can be achieved up to a certain point. The optimum ground coverage calculated for the CSIRO solar tower configuration is in the range of 53%. Other heliostat field designs usually have ground coverage below 30%. The annual optical performance of the CSIRO field per square meters of reflector is about 9% higher than a radial stagger field of 30% ground coverage for a research tower, which was optimized to have the highest performance for the time frame from 10 a.m. until 2 p.m.
An Optimum Sizing Methodology for Combined Photovoltaic-Energy Storage Electricity Generation Configurations
Authors: Kaldellis J. K. , Zafirakis D. , Kavadias K. , Kondili E.
Published: April 2009

The electrification of autonomous electrical networks is in most cases described by low quality of electricity available at very high production cost. Furthermore, autonomous electrical networks are subject to strict constraints posing serious limitations on the absorption of renewable energy sources (RES)-based electricity generation. To bypass these constraints and also to secure a more sustainable electricity supply status, the concept of combining photovoltaic (PV) power stations and energy storage systems comprises a promising solution for small scaled autonomous electrical networks, increasing the reliability of the local network as well. In this context, the present study is devoted in developing a complete methodology, able to define the size of an autonomous electricity generation system, based on the maximum available solar potential exploitation at minimum electricity generation cost. In addition special emphasis is given in order to select the most cost-efficient energy storage configuration available. According to the calculation results obtained, one may clearly state that an optimum sizing combination of a PV generator along with an appropriate energy storage system may significantly contribute on reducing the electricity generation cost in several island electrical systems, providing also abundant and high quality electricity without the environmental and macro-economic impacts of the oil-based thermal power stations.
Effect of Chemical Treatment on the Optical Properties of a Cadmium Telluride Photovoltaic Device Investigated by Spectroscopic Ellipsometry
Authors: Kohli Sandeep , Manivannan Venkatesan , Hilfiker James N. , McCurdy Patrick R. , Enzenroth Robert A. , Barth Kurt L. , Smith Westcott P. , Luebs Richard , Sampath Walajabad S.
Published: April 2009

Spectroscopic ellipsometry has been successfully used to characterize the CdS/CdTe heterojunction solar cell deposited on TEC15 glass. The effects of copper treatment on the optical properties of a cadmium chloride treated photovoltaic device were investigated using ellipsometry. No changes in either the band gaps or critical points of CdTe layer were noticed as a result of copper treatment. The copper treated CdTe layer exhibited a higher refractive index in the visible and longer wavelengths (≤3 eV), as compared with the untreated layer. This was attributed to the increased disorder in the case of copper treated layer.
Exact Representations on Artificial Interfaces and Applications in Mechanics
Authors: Givoli Dan
Published: April 2009

In various areas of applied mechanics, there are instances where it is necessary or beneficial to represent the behavior of a mechanical system on an artificial boundary, or artificial interface, which is introduced into the system. Examples include, among others, the computational treatment of mechanical problems in infinite media, the solution of crack problems in fracture mechanics, the dynamical analysis of a mechanical system attached to a number of smaller subsystems, iterative domain decomposition methods, and the mathematical formulation of inverse problems. The representation of the solution on the interface may be approximate or exact. This article is concerned with exact representations. It explains the benefit in using such representations, compares them to approximate representations in various respects, surveys work that has been done in this field, and highlights applications in applied mechanics. It is the author’s opinion that despite the fact that approximate interface representations are more popular than exact ones, the latter have definite advantages in many situations. References cited in this review article number 163.
Recent Advances in Sensing and Control of Flexible Structures Via Piezoelectric Materials Technology
Authors: Sunar M. , Rao S. S.
Published: April 2009

Due to their special characteristics, piezoelectric materials can be used in distributed behavior sensing and control of flexible structures. These materials are usually incorporated with the precision sensing and control of highly adaptive intelligent structures. Many theoretical, numerical, and experimental research activities treating piezoelectricity in sensing and control of various flexible structures have been carried out over the last decade. This survey article aims at collecting the recent research studies in this important field. It contains 336 references which are classified according to their applications. A brief theory and history of piezoelectricity is also presented.
A Review of Solution Methods for Determining Effectiveness-NTU Relationships for Heat Exchangers With Complex Flow Arrangements
Authors: Sekulic´ D. P. , Shah R. K. , Pignotti A.
Published: April 2009

A number of approaches have been employed for the design and analysis of two-fluid heat exchangers. These approaches include the effectiveness (ε or P)-number of transfer units (NTU) method, the mean temperature difference method, and the ones using the Mueller and Roetzel charts. A comprehensive review is presented of solution methods for obtaining effectiveness-NTU relationships for simple and complex heat exchangers and heat exchanger assemblies. These include analytical methods for obtaining exact solutions, approximate (including semi-numerical and analog) methods, numerical methods, matrix formalism, and additional methods based on the properties of the exchanger configurations. Additional details that pertain to the Laplace transforms and matrix formalism that includes the chain rule methodology are discussed. A step-by-step procedure that illustrates the chain rule methodology is presented. This review article includes 73 references.
Mechanics of Cylindrical Shells With Non-Circular Cross-Section: A Survey
Authors: Soldatos Kostas P.
Published: April 2009

This article presents a review of the research work related to the mechanical behavior of non-circular cylindrical shells and shell segments. To this end, after a brief reference to the basic nomenclature that is mainly used, it initially provides quite a general framework for most of the relevant governing equations employed in the relevant literature. It proceeds with a review of the corresponding dynamic analyses, which are primarily grouped according to the geometrical configuration of the noncircular shell considered and secondarily according to the type of the mathematical model employed. These deal with the dynamics of closed cylindrical shells and open cylindrical panels based on classical (CST) or transverse shear deformable shell theories (SDST). The static analyses reviewed next are divided according to the nature of the physical problem considered and deal with small as well as with large deflections of statically loaded non-circular cylindrical shells. These include both linearized and geometrically nonlinear elastic stability analyses as well as the very few relevant studies that assumed an elastic-plastic response of the shell material constitution. This review article contains 196 references.
Position Analysis, Workspace, and Optimization of a 3-P̱PS Spatial Manipulator
Authors: Ruggiu M.
Published: April 2009

The present paper describes the analytical solution of position kinematics for a three degree-of-freedom parallel manipulator. It also provides a numeric example of workspace calculation and a procedure for its optimization. The manipulator consists of a base and a moving platform connected to the base by three identical legs; each leg is provided with a P̱PS chain, where P̱ designates an actuated prismatic pair, P stands for a passive prismatic pair, and S a spherical pair. The direct analysis yields a nonlinear system with eight solutions at the most. The inverse analysis is solved in three relevant cases: (i) the orientation of the moving platform is given, (ii) the position of a reference point of the moving platform is given, and (iii) two rotations (pointing) and one translation (focusing) are given. In the present paper it is proved that case (i) yields an inverse singularity condition of the mechanism; case (ii) provides a nonlinear system with four distinct solutions at the most; case (iii) allows the finding of some geometrical configurations of the actuated pairs for minimizing parasitic movements in the case of a pointing/focusing operation of the manipulator.
Interface stability in advanced high-κ-metal-gate stacks
Authors: Adelmann C. , Franquet A. , Conard T. , Witters T. , Ferain I. , Meersschaut J. , Jurczak M. , De Meyer K. , Kittl J. A. , Van Elshocht S.
Published: April 2009

Thin film reactions and interface formation in advanced high-κ-metal-gate stacks containing rare-earth oxides have been studied. In particular, interfacial reactions of Dy2O3 and HfSiO4 with TiN- or TaCN-based metals were studied. It is shown that Dy diffusion is considerably stronger than Hf diffusion. It is further demonstrated that for TaCN-based materials, the material density and the microstructure are of much larger influence than the chemical composition.
Thermal noise and the emergence of the arrow of time: A simple model
Authors: Pérez-Cárdenas Fernando C.
Published: April 2009

A two-dimensional model of distinguishable particles that obey reversible deterministic laws of motion is used to illustrate the role played by thermal noise in the emergence of irreversible macroscopic behavior. Particles move in an array of square cells with four possible directions of motion. Particles that coincide with one or more particles in the same cell rotate by 90°. We study the evolution of the system from a fine-grained perspective, which allows us to follow the trajectory of each particle, and a coarse-grained perspective. The loss of information due to coarse-graining is compared with the loss of information resulting from noise. It is shown how particle and system trajectories can be used to determine if a system is quasi-ergodic. A modification of the interaction rule ensures that particles undergo momentum-conserving collisions equivalent to those of a simple lattice gas.
The status of Galileo’s law of free-fall and its implications for physics education
Authors: Lehavi Yaron , Galili Igal
Published: April 2009

We have examined the understanding of students and physics teachers regarding Galileo’s law of free fall. Refining this law for an observer on the ground, which is usually neglected in textbooks, results in the acceleration of free fall being mass dependent. We found that physics students and high school teachers are unaware of the conditions for which Galileo’s law is valid, and the law is often identified with the equivalence principle.
Efficacy of Daptomycin in Implant-Associated Infection Due to Methicillin-Resistant
Staphylococcus aureus
: Importance of Combination with Rifampin
Authors: John Anne-Kathrin , Baldoni Daniela , Haschke Manuel , Rentsch Katharina , Schaerli Patrick , Zimmerli Werner , Trampuz Andrej
Published: April 2009

Limited treatment options are available for implant-associated infections caused by methicillin (meticillin)-resistant
Staphylococcus aureus
(MRSA). We compared the activity of daptomycin (alone and with rifampin [rifampicin]) with the activities of other antimicrobial regimens against MRSA ATCC 43300 in the guinea pig foreign-body infection model. The daptomycin MIC and the minimum bactericidal concentration in logarithmic phase and stationary growth phase of MRSA were 0.625, 0.625, and 20 μg/ml, respectively. In time-kill studies, daptomycin showed rapid and concentration-dependent killing of MRSA in stationary growth phase. At concentrations above 20 μg/ml, daptomycin reduced the counts by >3 log
10
CFU/ml in 2 to 4 h. In sterile cage fluid, daptomycin peak concentrations of 23.1, 46.3, and 53.7 μg/ml were reached 4 to 6 h after the administration of single intraperitoneal doses of 20, 30, and 40 mg/kg of body weight, respectively. In treatment studies, daptomycin alone reduced the planktonic MRSA counts by 0.3 log
10
CFU/ml, whereas in combination with rifampin, a reduction in the counts of >6 log
10
CFU/ml was observed. Vancomycin and daptomycin (at both doses) were unable to cure any cage-associated infection when they were given as monotherapy, whereas rifampin alone cured the infections in 33% of the cages. In combination with rifampin, daptomycin showed cure rates of 25% (at 20 mg/kg) and 67% (at 30 mg/kg), vancomycin showed a cure rate of 8%, linezolid showed a cure rate of 0%, and levofloxacin showed a cure rate of 58%. In addition, daptomycin at a high dose (30 mg/kg) completely prevented the emergence of rifampin resistance in planktonic and adherent MRSA cells. Daptomycin at a high dose, corresponding to 6 mg/kg in humans, in combination with rifampin showed the highest activity against planktonic and adherent MRSA. Daptomycin plus rifampin is a promising treatment option for implant-associated MRSA infections.
Polymorphism in PfMRP1 (
Plasmodium falciparum
Multidrug Resistance Protein 1) Amino Acid 1466 Associated with Resistance to Sulfadoxine-Pyrimethamine Treatment
Authors: Dahlström Sabina , Veiga M. Isabel , Mårtensson Andreas , Björkman Anders , Gil J. Pedro
Published: April 2009

Sulfadoxine-pyrimethamine (SP) remains widely recommended for intermittent preventive treatment against
Plasmodium falciparum
malaria for pregnant women and infants in Africa. Resistance to SP is increasing and associated primarily with mutations in the
P. falciparum dhfr
(
Pfdhfr
) and
Pfdhps
genes. This study aimed to explore the hypothetical association of genetic alterations in the
P. falciparum
multidrug resistance protein gene (
Pfmrp1
) with the in vivo response to SP by detecting the selection of single nucleotide polymorphisms (SNPs) following standard single-dose treatment administered to children with acute uncomplicated
P. falciparum
malaria in Tanzania. We detected significant selection of parasites carrying the
Pfmrp1
1466K allele in samples from children with recrudescent infections, with 12 (100%) of 12 such samples being positive for this allele, compared to 52 (67.5%) of 77 baseline samples (
P
= 0.017), in parallel with the selection of the
Pfdhfr Pfdhps
quintuple mutant haplotype in cases of recrudescence (
P
= 0.001). There was no association between the 1466K SNP and the
Pfdhfr Pfdhps
quintuple mutation, indicating independent selections. Our data point for the first time to a role for a
P. falciparum
multidrug resistance protein homologue in the antimalarial activity of SP. Moreover, they add to the growing evidence of the potential importance of
Pfmrp1
in antimalarial drug resistance.
A Module Located at a Chromosomal Integration Hot Spot Is Responsible for the Multidrug Resistance of a Reference Strain from
Escherichia coli
Clonal Group A
Authors: Lescat Mathilde , Calteau Alexandra , Hoede Claire , Barbe Valérie , Touchon Marie , Rocha Eduardo , Tenaillon Olivier , Médigue Claudine , Johnson James R. , Denamur Erick
Published: April 2009

Escherichia coli
clonal group A (CGA) commonly exhibits a distinctive multidrug antimicrobial resistance phenotype—i.e., resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, and trimethoprim (ACSSuTTp)—and has accounted for up to 50% of trimethoprim-sulfamethoxazole-resistant
E. coli
urinary tract infections in some locales. Annotation of the whole-genome sequencing of UMN026, a reference CGA strain, clarified the genetic basis for this strain's ACSSuTTp antimicrobial resistance phenotype. Most of the responsible genes were clustered in a unique 23-kbp chromosomal region, designated the genomic resistance module (GRM), which occurred within a 105-kbp genomic island situated at the
leuX
tRNA. The GRM is characterized by numerous remnants of mobilization and rearrangement events suggesting multiple horizontal transfers. Additionally, comparative genomic analysis of the
leuX
tRNA genomic island in 14 sequenced
E. coli
genomes showed that this region is a hot spot of integration, with the presence/absence of specific subregions being uncorrelated with either the phylogenetic group or the pathotype. Our data illustrate the importance of whole-genome sequencing in the detection of genetic elements involved in antimicrobial resistance. Additionally, this is the first documentation of the
bla
TEM
and
dhfrVII
genes in a chromosomal location in
E. coli
strains.
Identification of a Novel Variant of Staphylococcal Cassette Chromosome
mec
, Type II.5, and Its Truncated Form by Insertion of Putative Conjugative Transposon Tn
6012
Authors: Han Xiao , Ito Teruyo , Takeuchi Fumihiko , Ma Xiao Xue , Takasu Michihiko , Uehara Yoshio , Oliveira Duarte C. , de Lencastre Hermínia , Hiramatsu Keiichi
Published: April 2009

We identified two novel staphylococcal cassette chromosome
mec
(SCC
mec
) elements in sequence type 8 methicillin-resistant
Staphylococcus aureus
strains isolated in Japan: type II.5 SCC
mec
, whose J1 region was highly homologous to that of type I.2 SCC
mec
of strain PL72 (previously isolated in Poland), and its J1 region variant caused by the deletion/insertion of putative conjugative transposon Tn
6012
, identified in four
S. aureus
genomes.
Comparative Efficacies of Telavancin and Vancomycin in Preventing Device-Associated Colonization and Infection by
Staphylococcus aureus
in Rabbits
Authors: Darouiche Rabih O. , Mansouri Mohammad D. , Schneidkraut Marlowe J.
Published: April 2009

Telavancin is an investigational lipoglycopeptide antibiotic that is active against gram-positive pathogens. In an in vivo rabbit model, subtherapeutic (15-mg/kg) and therapeutic (30- or 45-mg/kg) doses of telavancin were demonstrated to be noninferior and superior to vancomycin (20 mg/kg), respectively, for preventing subcutaneous implant colonization and infection by
Staphylococcus aureus
.
AbaR5, a Large Multiple-Antibiotic Resistance Region Found in
Acinetobacter baumannii
Authors: Post Virginia , Hall Ruth M.
Published: April 2009

A multiply antibiotic-resistant
Acinetobacter baumannii
strain, 3208, contains the
aacC1
-orfP-orfP-orfQ
-aadA1
gene cassette array;
sul1
,
tetA
(A), and
aphA1b
genes; and a
mer
operon in a large region containing a novel transposon, Tn
6020
, and segments of Tn
1696
, Tn
21
, Tn
1721
, and Tn
5393
. This region is part of a genomic resistance island, AbaR5, related to and found in the same chromosomal position as AbaR1. This strain is the first European clone I isolate detected in Australia.
Anidulafungin Is Fungicidal and Exerts a Variety of Postantifungal Effects against
Candida albicans
,
C. glabrata
,
C. parapsilosis
, and
C. krusei
isolates
Authors: Nguyen Katherine T. , Ta Philip , Hoang Bich Thu , Cheng Shaoji , Hao Binghua , Nguyen M. Hong , Clancy Cornelius J.
Published: April 2009

Anidulafungin targets the cell walls of
Candida
species by inhibiting β-1,3-glucan synthase, thereby killing isolates and exerting prolonged postantifungal effects (PAFEs). We performed time-kill and PAFE experiments on
Candida albicans
(
n
= 4),
C. glabrata
(
n
= 3),
C. parapsilosis
(
n
= 3), and
C. krusei
(
n
= 2) isolates and characterized the PAFEs in greater detail. MICs were 0.008 to 0.125 μg/ml against
C. albicans
,
C. glabrata
, and
C. krusei
and 1.0 to 2.0 μg/ml against
C. parapsilosis
. During time-kill experiments, anidulafungin caused significant kills at 16× MIC (range, log 2.68 to 3.89) and 4× MIC (log 1.87 to 3.19), achieving fungicidal levels (≥log 3) against nine isolates. A 1-hour drug exposure during PAFE experiments resulted in kills ranging from log 1.55 to 3.47 and log 1.18 to 2.89 (16× and 4× MIC, respectively), achieving fungicidal levels against four isolates. Regrowth of all 12 isolates was inhibited for ≥12 h after drug washout. Isolates of each species collected 8 h after a 1-hour exposure to anidulafungin (16× and 4× MIC) were hypersusceptible to sodium dodecyl sulfate (0.01 to 0.04%) and calcofluor white (40 μg/ml). Moreover, PAFEs were associated with major cell wall disturbances, as evident in electron micrographs of viable cells, and significant reductions in adherence to buccal epithelial cells (
P
≤ 0.01). Finally, three of four PAFE isolates tested were hypersusceptible to killing by J774 macrophages (
P
≤ 0.007). Our data suggest that the efficacy of anidulafungin in the treatment of candidiasis might stem from both direct fungicidal activity and indirect PAFEs that lessen the ability of
Candida
cells to establish invasive disease and to persist within infected hosts.