bluuebunny/crossref_metadata_2025 huggingface dataset:
Responsive materials
Authors: Alexander Cameron , Gill Iqbal
Published: February 2011

Responsive materials cover a breadth of types and many application fields. The common feature in all cases is a nonlinear change in properties or behavior as a result of a stimulus. The material response can range from a simple change in conformation or ionization state, through to phase transitions, bulk aggregation, or complete dissolution. As a consequence, sensing and actuation are the most investigated functions of these materials. In this issue, we have chosen to focus on responsive materials as exemplified by externally switchable, environmentally activated, and reversibly or controllably triggered systems. The chemistries of these materials, their physical properties, functional behavior, and activity are all linked, so we have aimed to cover the many disciplines underlying responsive materials through articles featuring areas that already span disparate research topics. These areas include drug delivery, smart surfaces, and nanotube transducers. The responsive materials field is growing in excitement as well as activity, and we hope that readers will gain an insight into this fascinating branch of materials science through this MRS Bulletin issue.
Nanotube responsive materials
Authors: Jayasinghe Chaminda , Li Weifeng , Song Yi , Abot Jandro L. , Shanov Vesselin N. , Fialkova Svitlana , Yarmolenko Sergey , Sundaramurthy Surya , Chen Ying , Cho Wondong , Chakrabarti Supriya , Li Ge , Yun Yeoheung , Schulz Mark J.
Published: February 2011

Individual nanotubes made of carbon, boron nitride, iron, silicon, or other materials have properties such as high strength, toughness, electrical and thermal conductivity, and light weight that cannot be matched by conventional materials. Nanotubes also change their properties in response to external fields and change one type of energy into another, which are useful for design. This article explores three main steps in exploiting responsive materials based on nanotubes: nanotube synthesis, macroscale material fabrication, and incorporation into device structures for novel applications. Nanotubes are always synthesized as individual particles in the form of powders, smoke particles, or aligned forests. To be industrially important, nanotubes generally must be processed to form derivative materials such as functionalized/coated powders and forests and macroscale intermediate materials such as sheets, ribbon, and yarn. The processed nanotubes are then used to develop responsive materials and devices that are able to resist, react to, or generate energy from their environment. This article provides background information and ideas on how to develop nanotube responsive materials for everyday use.
Processing of nanostructured metals and alloys via plastic deformation
Authors: Zhu Yuntian , Valiev Ruslan Z. , Langdon Terence G. , Tsuji Nobuhiro , Lu Ke
Published: February 2011

Plastic deformation can effectively produce nanostructured metals and alloys in bulk or surface-layer forms that are suitable for practical structural or functional applications. Such nanostructured materials are porosity-free and contamination-free, and therefore they are ideal for studying fundamental mechanisms and mechanical properties. In this article, we first give an overview of the principles of grain refinement by plastic deformation and an introduction to the reported processing techniques. Then the four most-developed and promising techniques will be described in detail: equal-channel angular pressing, high-pressure torsion, accumulative roll bonding for bulk nanostructured metals, and surface mechanical attrition treatment for nanostructured surface layers.
Metal deformation and phase transitions at extremely high strain rates
Authors: Rudd R. E. , Germann T. C. , Remington B. A. , Wark J. S.
Published: February 2011

The powerful lasers being constructed for inertially confined fusion generate enormous pressures extremely rapidly. These extraordinary machines both motivate the need and provide the means to study materials under extreme pressures and loading rates. In this frontier of materials science, an experiment may last for just 10s of nanoseconds. Processes familiar at ambient conditions, such as phase transformations and plastic flow, operate far from equilibrium and show significant kinetic effects. Here we describe recent developments in the science of metal deformation and phase transitions at extreme pressures and strain rates. Ramp loading techniques enable the study of solids at high pressures (100s of GPa) at moderate temperatures. Advanced diagnostics, such as in situ x-ray scattering, allow time-resolved material characterization in the short-lived high-pressure state, including crystal structure (phase), elastic compression, the size of microstructural features, and defect densities. Computer simulation, especially molecular dynamics, provides insight into the mechanisms of deformation and phase change.
In situ characterization of metals at extremes
Authors: Browning N. D. , Campbell G. H. , Hawreliak J. A. , Kirk M. A.
Published: February 2011

The fundamental processes taking place in metals under extreme conditions can occur on ultrafast timescales (i.e., nanoseconds to picoseconds), and yet their result can continue to have a significant impact on the structural properties for many years to follow. The challenge in developing in situ methods for characterization under extreme conditions therefore involves both the modification of the instrumentation to implement the high-temperature, strain, and radiation conditions and the definition of the timescale over which the measurement must be made. While techniques are well established for characterization of the long-term effects of extreme conditions, experiments are only just beginning to probe the initial stages of structural evolution. This article reviews recent developments in optical, x-ray, and electron probes of metals under extreme conditions and also discusses the needs for future experiments and potential pathways to achieving these goals.
Environmental impact of the nuclear fuel cycle: Fate of actinides
Authors: Ewing Rodney C. , Runde Wolfgang , Albrecht-Schmitt Thomas E.
Published: February 2011

The resurgence of nuclear power as a strategy for reducing greenhouse gas (GHG) emissions has, in parallel, revived interest in the environmental impact of actinides. Just as GHG emissions are the main environmental impact of the combustion of fossil fuels, the fate of actinides, consumed and produced by nuclear reactions, determines whether nuclear power is viewed as an environmentally “friendly” source of energy. In this article, we summarize the sources of actinides in the nuclear fuel cycle, how actinides are separated by chemical processing, the development of actinide-bearing materials, and the behavior of actinides in the environment. At each stage, actinides present a unique and complicated behavior because of the 5felectronic configurations.
A Challenge to Write
Authors: DeFauw Danielle
Published: January 2011

Can we really teach writing when we aren't writers ourselves? The author describes what happened when she made time for writing—and how her experience as a writer improved her teaching and benefited her students.
What Makes Writing Good? An Essential Question for Teachers
Authors: Nauman April D. , Stirling Terry , Borthwick Arlene
Published: January 2011

The question of what makes writing “good” touches several important areas of classroom writing instruction: assessment and evaluation, instruction, and teacher response during one‐on‐one conferences. The current paper examines contemporary views of what makes writing “good,” along with the classroom implications and limitations of these views. In addition, a research study investigating different perspectives on what makes writing “good” is reported. The study included 60 classroom teachers from urban high‐needs schools as well as suburban schools, preservice teachers, and professional writers. A Q methodological analysis identified three perspectives. Participants expressing perspective 1 defined good writing as good thinking and communication. In Perspective 2, structure and clarity were considered most essential to good writing. In Perspective 3, purpose, voice, and conventions were emphasized. Participants' views differed greatly on the need for predictable organization in writing, the value of surprise, and the necessity of correct conventions. Classroom implications are discussed.
Oral Impact on Daily Performance, Personality Traits, and Compliance in Periodontal Maintenance Therapy
Authors: Costa Fernando Oliveira , Miranda Cota Luís Otávio , Pereira Lages Eugênio José , Vilela Câmara Gislene Clemente , Cortelli Sheila Cavalca , Cortelli José Roberto , Costa José Eustáquio , Medeiros Lorentz Telma Campos
Published: February 2011

Background: To our knowledge, the association between personality traits and oral health impacts on daily activities among patients under periodontal maintenance was not previously evaluated. The present study aims to determine the oral health impacts among regular‐ and erratic‐complier patients and their correlations with personality traits by means of the oral impacts on daily performance (OIDP) and the neuroticism extraversion openness five‐factor inventory (NEO FFI‐R) instruments.

Methods: A total of 58 regular and 58 erratic compliers matched by sex, diabetes, and smoking were recruited from a cohort of 238 participants under periodontal maintenance. Periodontal examinations and questionnaire applications were performed in recalls during a 3‐year interval. The influence of variables of interest on the OIDP was evaluated through univariate and multivariate linear regression analyses.

Results: The periodontal status of regular compliers was significantly better than that of erratic compliers. Erratic compliers presented higher OIDP scores (36.34 ± 6.64) compared to regular compliers (30.45 ± 7.72). Higher scores of neuroticism and conscientiousness (R2 = 68%; P <0.001) were associated with higher OIDP scores among regular compliers, whereas among erratic compliers, lower scores of neuroticism, higher openness, and extraversion (R2 = 77%; P = 0.001) were associated with higher OIDP scores.

Conclusion: Personality traits, mainly neuroticism, showed significant influences on OIDP among patients under periodontal maintenance.
Cytokines and Bone‐Related Factors in Systemically Healthy Patients With Chronic Periodontitis and Patients With Type 2 Diabetes and Chronic Periodontitis
Authors: Vieira Ribeiro Fernanda , de Mendonça Adriana Cutrim , Santos Vanessa Renata , Bastos Marta Ferreira , Figueiredo Luciene Cristina , Duarte Poliana Mendes
Published: February 2011

Background: This study compares the levels of cytokines and bone‐related factors in the gingival crevicular fluid (GCF) of systemically healthy patients with chronic periodontitis (CP); and better‐controlled, and poorly controlled patients with type 2 diabetes and CP.

Methods: Thirty‐seven patients with type 2 diabetes and CP and 20 systemically healthy patients with CP were enrolled in this study. The patients with diabetes mellitus were categorized as better‐controlled (n = 17; HbA1c levels ≤8%) or poorly controlled (n = 20; glycated hemoglobin values >8%). Levels of tumor necrosis factor‐α, interleukin (IL)‐4, interferon (IFN)‐γ, IL‐23, IL‐17, soluble receptor activator of nuclear factor‐kappa B ligand (sRANKL), and osteoprotegerin (OPG) in GCF of diseased sites were analyzed by enzyme‐linked immunosorbent assay.

Results: Type 2 diabetes mellitus, as a whole, upregulates the levels of OPG, sRANKL, IFN‐γ, IL‐17, and IL‐23 and downregulates the production of IL‐4 in sites with CP (P <0.05). Better‐controlled individuals exhibited the highest levels of IFN‐γ, whereas poorly controlled patients presented the highest levels of IL‐17 (P <0.05). There were no differences in the levels of tumor necrosis factor‐α, OPG, and IL‐23 among systemically healthy, better‐controlled, and poorly controlled patients with diabetes (P >0.05).

Conclusions: Increased levels of proinflammatory cytokines and RANKL were observed in the GCF of patients with type 2 diabetes with CP, compared to patients without diabetes. In addition, poor or good glycemic status seems to modulate osteo‐immunoinflammatory mediators in a different manner.
Study on the removal of acid dyes using chitosan as a natural coagulant/coagulant aid
Authors: Zonoozi M. H. , Alavi Moghaddam M. R. , Arami M.
Published: February 2011

Chitosan was selected as a natural coagulating agent for the removal of acid dyes (Acid Blue 292; AB292, and Acid Red 398; AR398) from dye-containing solutions. The study was organised in two phases. In phase 1, chitosan was used alone as a natural coagulant for the removal of the dyes. For this purpose, the effect of different parameters including pH, chitosan dosage and initial dye concentration on the dye removal efficiency was examined. In phase 2 of the study, the application of chitosan as a natural coagulant aid in conjunction with polyaluminium chloride (PAC) was assessed. According to the results of phase 1, the best removal efficiencies occurred in an acidic pH range (less than 6) for both of the dyes. Also, excellent dye removal results (about 90%) were achieved with relatively low dosages of chitosan (30–35 mg L−1 for AB292 and 50–60 mg L−1 for AR398). However, the initial concentration of the dyes severely influenced the coagulation performance of chitosan, which can constrain the performance of chitosan as a natural coagulant. On the basis of the results of phase 2, chitosan, as a natural coagulant aid, noticeably enhanced the dye removal efficiency of PAC, especially in the case of AB292. Small amounts of chitosan (3 or 5 mg L−1) enhanced the dye removal efficiency of PAC up to 2.5 times for AB292.
Degradation of surfactant wastewater under microwave irradiation in the presence of activated carbon assisted with nano-sized TiO2 or nano-sized ZnO
Authors: Zhang Z. , Xu D. , Shen M. , Wu D. , Chen Z. , Ji X. , Li F. , Xu Y.
Published: February 2011

An improved method treating surfactant wastewater by the addition of semiconductor material such as nano-sized TiO2 or ZnO to activated carbon (AC) with microwave (MW) irradiation was proposed so as to assist efficient degradation of organic pollutants. A series of degradation experiments of sodium dodecyl benzene sulfonate (SDBS) were carried out under MW irradiation in the presence of AC/TiO2 or AC/ZnO. The influences of catalyst dose, irradiation time, initial SDBS concentration and solution acidity on the degradation were assessed in detail. The results showed that the addition of TiO2 or ZnO obviously promoted the degradation and AC/TiO2 system displayed higher catalytic activity under MW irradiation. Thus the method of MW irradiation with AC/TiO2 or AC/ZnO revealed many advantages of rapid degradation rate, short irradiation time, low cost, no residual intermediates and no secondary pollution in applications.
Removal of ammonium from rare-earth wastewater using natural brucite as a magnesium source of struvite precipitation
Authors: Huang H. M. , Xiao X. M. , Yang L. P. , Yan B.
Published: February 2011

This paper presents a study regarding ammonium removal from rare-earth wastewater by struvite precipitation with natural brucite mineral as a source of magnesium. Experimental results indicated that a pH ranging from 8.5 to 9.5 was the optimum for the removal of ammonium using the soluble form of brucite as a magnesium source. Additionally, when solid brucite was used as a magnesium source as well as an alkali reagent, the initial ammonium concentration of 4,535 mg/L decreased to 239–317 mg/L after an reaction time of 12 h in wastewater treated with the S/L (solid brucite/liquid wastewater) ratios ranging from 31.2 to 63.2 g/L. Furthermore, as some non-reacted brucite still remained in the precipitates obtained at the end of reaction, the precipitates were subjected to reuse. The reuse results demonstrated that the reuse of the precipitates obtained with 63.2 g/L was feasible, and almost half of the brucite dose could be saved.
Past, present, and future design of urban drainage systems with focus on Danish experiences
Authors: Arnbjerg-Nielsen K.
Published: February 2011

Climate change will influence the water cycle substantially, and extreme precipitation will become more frequent in many regions in the years to come. How should this fact be incorporated into design of urban drainage systems, if at all? And how important is climate change compared to other changes over time? Based on an analysis of the underlying key drivers of changes that are expected to affect urban drainage systems the current problems and their predicted development over time are presented. One key issue is management of risk and uncertainties and therefore a framework for design and analysis of urban structures in light of present and future uncertainties is presented.
Life cycle assessment of three water systems in Copenhagen–a management tool of the future
Authors: Godskesen B. , Zambrano K. C. , Trautner A. , Johansen N. -B. , Thiesson L. , Andersen L. , Clauson-Kaas J. , Neidel T. L. , Rygaard M. , Kløverpris N. H. , Albrechtsen H. -J.
Published: February 2011

Environmental life-cycle assessment (LCA) was applied to evaluate three different water systems of the water sector in Copenhagen, Denmark, including technologies within water supply, facilities recycling water and treatment of sewer overflow. In these three water systems LCA was used to evaluate the environmental impacts of each of the processes involved. The overall conclusion was that LCA is suitable as a decision support tool in the water sector as it provides a holistic evaluation platform of the considered alternatives categorised in environmental impact categories. The use of LCA in the water sector of this region has limitations since it does not yet consider impact categories assessing freshwater scarcity and ecological sustainability.
Application of immobilized waste brewery yeast cells for Cd2+ removal: Equilibrium and kinetics
Authors: Tonk Szende , Măicăneanu Andrada , Indolean Cerasella , Burca Silvia , Majdik Cornelia
Published: February 2011

In this investigation, the removal of Cd2+ ions by a brewery waste biomass in
immobilized (Ca-alginate beads) form was studied. The removal process was
conducted at room temperature under batch conditions (magnetic stirring)
using different initial cadmium concentrations. The equilibrium of
biosorption was reached in 150 minutes for all employed initial
concentrations. The maximum biosorption capacity was calculated to be 5.96 mg
Cd2+ g-1 yeast for an initial Cd2+ concentration of 169 mg L-1. Langmuir and
Freundlich adsorption isotherms were used to correlate the equilibrium
adsorption data. Based on the correlation coefficients, it was concluded that
the Langmuir isotherm is more suitable for describing the equilibrium data of
cadmium biosorption. In addition, first and pseudo-second order kinetic
models were applied to describe the biosorption process. The kinetic
parameters for the pseudo-second order kinetics were determined.
An overview of the effects of thermal processing on bioactive glasses
Authors: Bellucci D. , Cannillo V. , Sola A.
Published: January 2011

Bioglass? 45S5 is widely used in biomedical applications due to its ability
to bond to bone and even to soft tissues. The sintering ability of Bioglass?
powders is a key factor from a technological point of view, since its govern
the production of advanced devices, ranging from highly porous scaffolds to
functionalized coatings. Unfortunately this particular glass composition is
prone to crystallize at the temperature required for sintering and this may
impair the bioactivity of the original glass. For these reasons, a
prerequisite to tailor the fabrication of Bioglass?-derived implants is to
understand the interaction between sintering, crystallization and
bioactivity. In this work the structural transformations which occur during
the heat treatment of Bioglass? are reviewed and a special attention is paid
to the sintering and crystallization processes. Moreover the bioactivity of
the final glass-ceramics is discussed and some alternative glass formulations
are reported.
Triglycerides and Amputation Risk in Patients With Diabetes
Authors: Callaghan Brian C. , Feldman Eva , Liu Jennifer , Kerber Kevin , Pop-Busui Rodica , Moffet Howard , Karter Andrew J.
Published: February 2011

OBJECTIVE

To determine the association between triglyceride levels and lower-extremity amputation (LEA) risk in a large diabetic cohort.

RESEARCH DESIGN AND METHODS

This is a 10-year survey follow-up study (from 1995–2006) of 28,701 diabetic patients with a baseline triglyceride measure. All patients were fully insured members of the Kaiser Permanente Medical Care Program and responded to a survey at baseline that included information on ethnicity, socioeconomic status, education, behavioral factors, and information required to determine type of diabetes. The relationship between triglycerides and time to incident nontraumatic LEA, defined by primary hospitalization discharge or procedures, was evaluated using Cox proportional hazards models.

RESULTS

Triglyceride level was an independent, stepwise risk factor for nontraumatic LEAs within this large diabetic cohort: triglycerides 150–199 mg/dL, hazard ratio (HR) 1.10 (95% CI 0.92–1.32); 200–499 mg/dL, 1.27 (1.10–1.47); >500 mg/dL, 1.65 (1.30–2.10) (reference <150 mg/dL).

CONCLUSIONS

Hypertriglyceridemia is a significant risk factor for LEA in diabetic patients even after controlling for known socioeconomic, health behavioral, and clinical factors. This previously unrecognized clinical risk needs to be further investigated to determine if treatment of triglycerides can reduce amputation risk.
Exenatide Twice Daily Versus Premixed Insulin Aspart 70/30 in Metformin-Treated Patients With Type 2 Diabetes
Authors: Gallwitz Baptist , Böhmer Michael , Segiet Thomas , Mölle Andrea , Milek Karsten , Becker Bernd , Helsberg Karin , Petto Helmut , Peters Natalie , Bachmann Oliver
Published: February 2011

OBJECTIVE

Hypoglycemia causes recurrent morbidity in patients with type 2 diabetes. This study evaluated if exenatide twice daily (BID) was noninferior to premixed insulin aspart 70/30 BID (PIA) for glycemic control and associated with less hypoglycemia.

RESEARCH DESIGN AND METHODS

In this open-label study, metformin-treated adults with type 2 diabetes were randomized to 26-week treatment with exenatide BID (4 weeks 5 μg, then 10 μg) or PIA.

RESULTS

Exenatide BID (n = 181) was noninferior to PIA (n = 173) for A1C control (least squares [LS] mean change −1.0 vs. −1.14%; difference [95% CI] 0.14 [−0.003 to 0.291]) and associated with a lower risk for hypoglycemia (8.0 vs. 20.5%, P < 0.05). LS mean weight decreased by 4.1 kg and increased by 1.0 kg with PIA (P < 0.001). A total of 39.2 vs. 20.8% of patients reached the composite end point of A1C <7.0%, no weight gain, and no hypoglycemia (P < 0.001; post hoc analysis).

CONCLUSIONS

In metformin-treated patients, exenatide BID was noninferior to PIA for glycemic control but superior for hypoglycemia and weight control.
Neuroblastomas with Discordant Genotype-Phenotype Relationships: Report of Four Cases with MYCN Amplification and Favorable Histology
Authors: Nakagawa Atsuko , Matsuoka Kentaro , Okita Hajime , Iwafuchi Hideto , Hori Hisanari , Kumagai Masaaki
Published: February 2011

MYCN amplification prevents cellular differentiation and promotes mitotic and karyorrhectic activities in neuroblastomas. Hence, MYCN-amplified tumors typically show an appearance of neuroblastoma of either an undifferentiated or a poorly differentiated subtype with a high mitosis-karyorrhexis index. In addition, they are classified as part of the unfavorable histology group, according to the International Neuroblastoma Pathology Classification. Large cell type and/or presence of prominent nucleoli is also reported to be an additional hallmark of MYCN amplification. However, there are few neuroblastomas having MYCN amplification and favorable histology. Four cases of MYCN amplification and favorable histology were identified in our file of 63 cases of neuroblastoma. The patients (M:F = 3:1) were diagnosed between 6 and 13 months of age, and all had adrenal primary tumors and were treated with high-dose therapy and autologous stem cell rescue. Three patients (stages 1, 3, and 4) are alive and well 7 years, 26 months, and 19 months after diagnosis, respectively. One patient with stage 4 disease died 8 months after diagnosis. Their tumors showed the same histologic feature of neuroblastoma: poorly differentiated subtype with a low mitosis-karyorrhexis index; they were not qualified as large cell type and had no prominent nucleoli. MYCN amplification of those tumors was confirmed by fluorescence in situ hybridization in all 4 cases, but MYCN protein expression was not demonstrated by immunohistochemistry (4 cases) and MYCN mRNA was not detected by reverse transcriptase polymerase chain reaction (1 case). Those cases showed a discrepant genotype-phenotype that was not simply a laboratory observation but could indicate the concept that that MYCN amplification did not automatically equate to a poor prognosis in this group of patients.
High-Definition Imaging in Endoscopic Transsphenoidal Pituitary Surgery
Authors: Conrad Jens , Philipps Mark , Oertel Joachim
Published: January 2011

Background

The transsphenoidal approach to sellar lesions has evolved enormously since its first description in the early 20th century. Endoscopic surgical strategies have become an integral part of the surgical armamentarium. More recently, high-definition (HD) digital cameras with better image resolution were introduced, although their value for the surgical procedure remains equivocal. The purpose of this study was to compare the image quality of a standard-definition (SD) camera with a new HD camera.

Methods

A transsphenoidal pituitary adenomectomy was recorded simultaneously in HD and SD resolution. Eight experienced neurosurgeons were asked to identify predefined as well as not predefined anatomic structures in HD and SD. Additionally, the video quality of three complementary surgical sequences was rated with grades from 1 (“very good”) to 6 (“poor”).

Results

An average of 23.6 ± 2.7 predefined structures (84.38%) were identified in HD versus 17.6 ± 4.4 predefined structures (62.95%) identified in SD. This profound difference in the recognition of anatomic structures reached statistical significance (p = 0.012). Subjective impression of video quality was rated 1.9, 1.9, and 1.4 for the videos in HD and 3.5, 3.3, and 3.5 for the complementary videos in SD. These differences also reached statistical significance (p ≤ 0.005).

Conclusion

HD imaging in endoscopic transsphenoidal pituitary surgery accounts for significantly better identification of anatomic structures in comparison with SD images. Additionally, the subjective impression of video quality is significantly better in HD. This improved intraoperative orientation by better digital image quality might contribute to reduce the gap in intraoperative visual accuracy between microsurgery and endoscopy in pituitary surgery.
Detection of Bacteria in Normal Adult Nasal Cavity Based on Polymerase Chain Reaction–denaturing Gradient Gel Electrophoresis
Authors: Cho Jae Hoon , Jung Min Young , Kim Jin Kook , Chang Young-Hyo
Published: January 2011

Background

This study investigated the bacterial diversity in a normal adult nasal cavity using polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) of 16S ribosomal RNA (rRNA) gene fragments and compared the results with those of a culture-based method.

Methods

We swabbed the inferior turbinate from 19 normal volunteers. The transport media was divided by two, one for bacterial culture and another direct extraction for bacterial DNA. PCR-DGGE was performed from the bacterial DNA and all of the sequences were compared with the reference organism by using the BLAST program (a genome database of GenBank in the National Center for Biotechnology Information, Bethesda, MD).

Results

All 224 colonies were obtained from 19 samples by using a culture-based method; however, only 9 kinds of bacteria were detected. Staphylococcus epidermidis was the most frequently detected bacteria, and Staphylococcus aureus was the second most. The detection rates of other bacteria were very low. On the other hand, the PCR-DGGE from direct DNA extraction revealed 34 different bands that corresponded to 23 different kinds of bacteria. There were nine genera, viz., Staphylococcus, Bacillus, Enterobacter, Corynebacterium, Actinobacterium, Hafnia, Moraxella, Dolosigranulum, and Clostridium. Among them, unspecific Staphylococcus species and Enterobacter aerogenes were detected most frequently.

Conclusion

Compared with the previous culture-based method, PCR-DGGE can detect much more diversity of bacteria in the nasal cavity.
Limnochemistry of Three Freshwater Springs of Kashmir Himalaya
Authors: Bhat Sami Ullah , Pandit Ashok K.
Published: January 2011

The present investigation was carried out during 2005-06 on three limnocrene freshwater springs located in single groundwater area in Kokergund (Yaripora) of District Kulgam, Kashmir, India. A perusal of the data showed that these springs were hard water type with slightly lower values of dissolved oxygen (DO) (1.2-6.4mg/L). The ionic composition of the spring waters revealed the predominance of bicarbonate and calcium over the other ions with usual ionic progression as HCO3- >Ca++ >Mg++ >Na+ >K+. None of the parameters studied foated the standards set by WHO for drinking water quality. However, relatively higher values of NO3-N (2500-3900µg/L), but well within the per-missible limits of WHO, were observed. The dissolved silica did not show any temporal variation between the different months but exhibited slight spatial variations (17.8-21mg/L).Key words: Limn chemistry; Water quality; Groundwater; Kashmir HimalayaDOI: 10.3126/hn.v7i0.4237Hydro Nepal Journal of Water, Energy and Environment Vol. 7, July, 2010Page: 54-59Uploaded date: 31 January, 2011
Derivation of Global Parametric Performance of Mixed Flow Hydraulic Turbine Using CFD
Authors: Khare Ruchi , Prasad Vishnu Prasad , Kumar Sushil
Published: January 2011

The testing of physical turbine models is costly, time consuming and subject to limitations of laboratory setup to meet International Electro technical Commission (IEC) standards. Computational fluid dynamics (CFD) has emerged as a powerful tool for funding numerical solutions of wide range of flow equations whose analytical solutions are not feasible. CFD also minimizes the requirement of model testing. The present work deals with simulation of 3D flow in mixed flow (Francis) turbine passage; i.e., stay vane, guide vane, runner and draft tube using ANSYS CFX 10 software for study of flow pattern within turbine space and computation of various losses and efficiency at different operating regimes. The computed values and variation of performance parameters are found to bear close comparison with experimental results.Key words: Hydraulic turbine; Performance; Computational fluid dynamics; Efficiency; LossesDOI: 10.3126/hn.v7i0.4239Hydro Nepal Journal of Water, Energy and EnvironmentVol. 7, July, 2010Page: 60-64Uploaded date: 31 January, 2011
An Interview with Dr. Sandip Shah; President of Independent Power Producers Association of Nepal (IPPAN)
Authors: Thanju Jeevan P
Published: January 2011

Not available.Interview with Dr. Sandip Shah; President of Independent Power Producers Association of Nepal (IPPAN)DOI: 10.3126/hn.v7i0.4243Hydro Nepal Journal of Water, Energy and Environment Vol. 7, July, 2010 Page: 92-94 Uploaded date: 31 January, 2011
Monitoring Drinking
Authors: Voas Robert B.
Published: February 2011

Individuals convicted of driving while impaired (DWI) are high risks. They are two and a half times more likely than the average driver to be the drinking driver in a fatal crash and are responsible for approximately 1,000 alcohol-related fatalities each year. According to traditional means of control, DWI offenders have received jail time and have had their licenses suspended, but jail is expensive, and license suspension has not proved sufficiently effective. Recently, aided by new technologies, courts of law have begun to monitor offenders to ensure abstinence from alcohol and to control their driving through vehicle alcohol interlocks, which require a breath test to start a car. This paper describes these new monitoring programs and discusses the safety, health, and legal issues that they present. Aside from vehicle interlocks, most of these new technological methods have yet to be evaluated, but initial data appear promising. They suggest that even individuals dependent on alcohol can meet the requirements of alcohol-monitoring programs. However, the need for counseling assistance is likely to increase the role of court treatment programs to handle DWI offenders. If monitoring programs prevent recidivism, a new era may begin: current emphasis on license suspension and jail time for drivers convicted for drinking may give way to monitoring programs to control risky driving, with the potential to lower costs to government and reduce intrusion into the lives of offenders.
Seat Belt Use on Alabama School Buses
Authors: Tedla Elsa , Turner Daniel S. , Lindly Jay K.
Published: February 2011

The Alabama State Department of Education commissioned a study of school bus seat belt use on the basis of 12 buses (less than 1% of the fleet) equipped with seat belts and digital camera systems. The initial year of the study established baseline rates for normal situations. About 64,000 pupil observations were gathered from 11 buses on Tuesday through Thursday afternoon routes and from one control bus on Monday through Friday morning and afternoon routes. Afternoon route seat belt use was estimated to be 65.9% on the basis of 44,000 of the observations made. Given the small sample size, this value should be considered representative of the fleet but not exact. Belt use varied widely from bus to bus (94.5% to 4.8%). The degree of scatter was confirmed by large values of the coefficient of variation. Trends were documented for variation by day of week, morning versus afternoon, time on route, effects of bus aides, and changes in use over the school year. The findings confirmed the opinions of national experts and Alabama pupil transportation managers. High seat backs blocked the view of drivers as they tried to control pupil conduct and enforce seat belt use. The researchers of the University Transportation Center for Alabama examined digital images of pupils on the buses, but they could determine whether a seat belt was used only 65% of the time. While driving, bus drivers are able to see far fewer pupils: it is unrealistic to expect the drivers to enforce seat belt use.
Travel Behavior in Aging Societies
Authors: Buehler Ralph , Nobis Claudia
Published: February 2011

The number of older Americans is predicted to increase significantly over the next 30 years. Germany has already experienced a similar challenge over recent decades. In 2005, the share of population 65 years and older was 20% in that country, a share predicted for the United States around 2030. Both countries have among the highest motorization rates in the world, and almost all adults are licensed drivers. A comparison of the United States and Germany can provide important lessons about determinants of travel behavior of the elderly. This study traced changes in travel behavior over time in both countries using German national travel surveys from 1982 and 2002 and U.S. national travel surveys from 1983 and 2001. The study then investigated differences in determinants of travel behavior between the two countries through a multiple regression analysis based on the 2002 German travel survey and the 2001 U.S. travel survey. In both countries all social groups—but most markedly the elderly—were found to be more mobile today than 20 years ago. In both countries, travel behavior of 45 to 64 year olds in the early 1980s was a good predictor of travel behavior of 65+ year olds in 2001. Once travel behavior is adopted, it seems to carry on into older age. Besides similar trends in each country, elderly Americans were found to make more trips by car than Germans. This difference held even when controlling for socioeconomic and demographic factors and spatial development patterns. Transportation policies can help explain this difference. Compared with the United States, policies in Germany make car use more expensive and particularly more difficult in cities. At the same time, public policies make cycling and public transportation easy to use, cheap, safe, convenient, and accessible transportation alternatives for a less car-dependent lifestyle into old age.
Implementation of Road Safety Audit Recommendations
Authors: Heaslip Kevin , Jones Josh , Harpst Tim , Bolling Doyt
Published: February 2011

As road safety audits (RSAs) have been implemented by agencies across the United States, transportation professionals have realized that RSAs are an effective tool to proactively improve the future safety performance of a roadway during the planning and design stages and to identify safety issues in existing transportation facilities. But limited study has been done of the implementation of RSA recommendations on existing roadways. The Utah Local Technical Assistance Program Center conducted an RSA of 1300 East in Salt Lake City, Utah. The rapid implementation of the recommendations was one of the major successes of the project. In addition, a public involvement process refined the recommendations and helped develop a consensus that the safety improvements implemented would be accepted. The result of the safety audit was the implementation of countermeasures that should increase the safety of the roadway. The ability to introduce a bike lane and signalized crosswalks had a significant impact toward the goal of making roads more pedestrian- and bicycle-friendly and implementing a “complete street” solution. The roadway is now much more accessible to pedestrians and bicyclists while maintaining much of the mobility already in place for motorized vehicles.
Addressing Equity in Political Debates over Road Pricing
Authors: Taylor Brian D. , Kalauskas Rebecca
Published: February 2011

Recent technological advances have made it easier and cheaper to charge vehicles for road use, and indeed electronic roadway tolling applications are gradually increasing worldwide. Although road pricing holds the promise of reducing congestion, emissions, and fuel use while raising needed revenues, the growth in toll programs and projects is halting and falls short of a groundswell. The idea remains generally unpopular with businesses, voters, and the people whom they elect. One of the concerns about road pricing is unfairness. While considerable ink has been spilled on the philosophical and empirical dimensions of road pricing, less has been written on how equity concerns have been addressed in practice. This paper addresses this gap by reviewing the broader road pricing equity literature and examining road pricing case studies in which equity debates played a prominent role. Four strategies have proven important to mitigating equity concerns and overcoming opposition to road pricing: addressing equity issues in planning, building support from the public and interest groups, establishing trust between elected officials and transportation agencies before project development, and enlisting the support of influential constituencies for toll revenues. The politics of transportation finance, especially road pricing, is complex and contentious, making it difficult to separate measurable equity outcomes from perceptions of fairness and beliefs about tolling from tactics to avoid paying them. However, the gradual operational and political success of a growing number of road pricing projects suggests that equity concerns can be satisfactorily addressed.
Making Congestion Pricing Equitable
Authors: Ecola Liisa , Light Thomas
Published: February 2011

Transportation policy makers increasingly consider congestion pricing a promising option for addressing urban traffic congestion problems. Although some congestion pricing projects have been undertaken in the United States, many proposals have been rejected because of concerns that congestion pricing is inequitable. This paper identifies and assesses ways of making congestion pricing equitable. The authors review notions of equity applicable to congestion pricing and explore the equity issues that arise in the context of cordon and area pricing systems and high-occupancy toll lanes.
Economic Incentives to Influence Drivers' Route Choices for Safety Enhancement
Authors: Bie Jing , Van Arem Bart , Igamberdiev Muzaffar
Published: February 2011

A route-based incentive program is introduced in which drivers are rewarded for taking the safest routes. The program is operated with an incentive structure by a logistics company and a variable insurance premium scheme by an insurance company. The logistics company offers incentives to its drivers to follow the safest routes and by doing so expects to pay lower insurance premiums for its vehicles. The insurance company charges a discounted premium for vehicles that follow the safest routes, while expecting to pay less for potential accident claims. The theoretical framework, including the setup of the incentive structure and the variable premium scheme, is presented in this paper. Conditions for the existence of a win–win situation are established in which drivers, the logistics company, and the insurance company all benefit from the program. Optimization of the incentive program is also formulated as a bilevel programming problem. An online before-and-after survey is conducted to assess drivers' response to incentives. Forty-five Dutch professional drivers participated in the survey. The results show that drivers tend to ignore safety-related information in making their route choices; however, the incentives have some significant effects on these choices. The incentives therefore present an effective way of influencing drivers' route choices.
Sustaining the Momentum
Authors: Kassens-Noor Eva
Published: February 2011

Positive urban impacts of the Olympic Games are often publicized but seldom evaluated empirically. Through analysis of Olympic transport plans and expert interviews, this paper tests whether transport measures implemented during the games were sustained in four host cities. The paper consists of three main parts. The first provides an overview of the challenges the Olympics impose on urban transport systems, primarily in terms of passenger transport. The second part reviews the long-term transport goals each city intended to achieve through the Olympics and categorizes transport measures implemented to handle the Olympic peak demand. The third part analyzes comparatively how the cities changed and, in particular, which of the measures that supported the passenger operations were sustained. Although planners, governments, and residents intended to use the Olympic Games as a catalyst for lasting transport improvements, actual implementations were mainly temporary. Only in a few instances did Olympic efforts lead to lasting benefits for urban transport systems. The paper suggests a long-term, comprehensive planning strategy for using the Olympics as a catalyst for change to sustain the momentum the games give to a host city.
Lagrangian Formulation of Multiclass Kinematic Wave Model
Authors: Van Wageningen-Kessels Femke , Van Lint Hans , Hoogendoorn Serge P. , Vuik Kees
Published: February 2011

The kinematic wave model is often used in simulation tools to describe dynamic traffic flow and to estimate and predict traffic states. Discretization of the model is generally based on Eulerian coordinates, which are fixed in space. However, the Lagrangian coordinate system, in which the coordinates move with the velocity of the vehicles, results in more accurate solutions. Furthermore, if the model includes multiple user classes, it describes real traffic more accurately. Such a multiclass model, in contrast to a mixed-class model, treats different types of vehicles (e.g., passenger cars and trucks or vehicles with different origins or destinations, or both) differently. The Lagrangian coordinate system is combined with a multiclass model, and a Lagrangian formulation of the kinematic wave model for multiple user classes is proposed. It is shown that the advantages of the Lagrangian formulation also apply for the multiclass model. Simulations based on the Lagrangian formulation result in more accurate solutions than simulations based on the Eulerian formulation.
Generic Calibration Framework for Joint Estimation of Car-Following Models by Using Microscopic Data
Authors: Hoogendoorn Serge P. , Hoogendoorn Raymond
Published: February 2011

Microscopic simulation models have become widely applied tools in traffic engineering. Nevertheless, parameter identification of these models remains a difficult task. This is partially because parameters are generally not directly observable from common traffic data; also there is a lack of reliable statistical estimation techniques. This study puts forward a new general and structured approach to identifying parameters of car-following models. One of the main contributions of this study is joint estimation of parameters for multiple vehicles. Furthermore, prior information on the parameter values (or the valid range of values) can be estimated. The study also deals with serial correlation in the trajectory data. In doing so, the newly developed approach generalizes the maximum likelihood estimation approach proposed by the authors. The approach allows for statistical analysis of the model estimates, including the standard error of the parameter estimates and the correlation of the estimates. With the likelihood ratio test, models of different complexity (defined by the number of model parameters) can be cross-compared. A useful property of this test is that it takes into account the number of parameters of a model as well as the performance. The approach is applied to car-following behavior by using Dutch freeway vehicle trajectories collected from a helicopter.
Macroscopic Characteristics of Lane-Changing Traffic
Authors: Jin Wen-Long
Published: February 2011

On a multilane roadway, systematic lane changes can seriously disrupt traffic flow and cause capacity reductions. Therefore it is important to understand the characteristics of lane-changing traffic flow. In a previous study, a new variable, lane-changing intensity, was theoretically derived by doubling the contribution to the total density of a lane-changing vehicle during its lane-changing period, and an intensity–density relation was incorporated into the fundamental diagram to capture such bottleneck effects at the aggregate level. In this study, a new interpretation of lane-changing intensity is proposed by following Edie's definition of traffic density. Detailed studies of macroscopic characteristics of lane-changing traffic with 75 min of vehicle trajectories collected for a freeway section on I-80 near San Francisco, California, by FHWA's next-generation simulation project are presented. About 10% misindentified lane changes are excluded. For different time intervals, cell sizes, and locations, the well-definedness of the lane-changing intensity variable and the intensity–density relation are verified.