bluuebunny/crossref_metadata_2025 huggingface dataset:
Streptococcus pyogenes Malate Degradation Pathway Links pH Regulation and Virulence
Authors: Paluscio Elyse , Caparon Michael G.
Published: January 2015

The ability of
Streptococcus pyogenes
to infect different niches within its human host most likely relies on its ability to utilize alternative carbon sources. In examining this question, we discovered that all sequenced
S. pyogenes
strains possess the genes for the malic enzyme (ME) pathway, which allows malate to be used as a supplemental carbon source for growth. ME is comprised of four genes in two adjacent operons, with the regulatory two-component MaeKR required for expression of genes encoding a malate permease (
maeP
) and malic enzyme (
maeE
). Analysis of transcription indicated that expression of
maeP
and
maeE
is induced by both malate and low pH, and induction in response to both cues is dependent on the MaeK sensor kinase. Furthermore, both
maePE
and
maeKR
are repressed by glucose, which occurs via a CcpA-independent mechanism. Additionally, malate utilization requires the PTS transporter EI enzyme (PtsI), as a PtsI
–
mutant fails to express the ME genes and is unable to utilize malate. Virulence of selected ME mutants was assessed in a murine model of soft tissue infection. MaeP
–
, MaeK
–
, and MaeR
–
mutants were attenuated for virulence, whereas a MaeE
–
mutant showed enhanced virulence compared to that of the wild type. Taken together, these data show that ME contributes to
S. pyogenes
' carbon source repertory, that malate utilization is a highly regulated process, and that a single regulator controls ME expression in response to diverse signals. Furthermore, malate uptake and utilization contribute to the adaptive pH response, and ME can influence the outcome of infection.
The decategorification of bordered Khovanov homology
Authors: Roberts Lawrence P.
Published: January 2015

In [A type D structure in Khovanov homology, preprint (2013), arXiv:1304.0463; A type A structure in Khovanov homology, preprint (2013), arXiv:1304.0465] the author constructed a package which describes how to decompose the Khovanov homology of a link ℒ into the algebraic pairing of a type D structure and a type A structure (as defined in bordered Floer homology), whenever a diagram for ℒ is decomposed into the union of two tangles. Since Khovanov homology is the categorification of a version of the Jones polynomial, it is natural to ask what the types A and D structures categorify, and how their pairing is encoded in the decategorifications. In this paper, the author constructs the decategorifications of these two structures, in a manner similar to I. Petkova's decategorification of bordered Floer homology, [The decategorification of bordered Heegaard-Floer homology, preprint (2012), arXiv:1212.4529v1], and shows how they recover the Jones polynomial. We also use the decategorifications to compare this approach to tangle decompositions with M. Khovanov's from [A functor-valued invariant of tangles, Algebr. Geom. Topol.2 (2002) 665–741].
Sun Protection Practices and Sun Exposure among Children with a Parental History of Melanoma
Authors: Glenn Beth A. , Lin Tiffany , Chang L. Cindy , Okada Ashley , Wong Weng Kee , Glanz Karen , Bastani Roshan
Published: January 2015

Background: First-degree relatives of melanoma survivors have a substantially higher lifetime risk for melanoma than individuals with no family history. Exposure to ultraviolet radiation (UVR) is the primary modifiable risk factor for the disease. Reducing UV exposure through sun protection may be particularly important for children with a parental history of melanoma. Nonetheless, limited prior research has investigated sun protection practices and sun exposure among these children.

Methods: The California Cancer Registry was used to identify melanoma survivors eligible to participate in a survey to assess their children's sun protection practices and sun exposure. The survey was administered by mail, telephone, or web to Latino and non-Latino white melanoma survivors with at least one child (0–17 years; N = 324).

Results: Sun exposure was high and the rate of sunburn was equivalent to or higher than estimates from average-risk populations. Use of sun protection was suboptimal. Latino children were less likely to wear sunscreen and hats and more likely to wear sunglasses, although these differences disappeared in adjusted analyses. Increasing age of the child was associated with lower sun protection and higher risk for sunburn, whereas higher objective risk for melanoma predicted improved sun protection and a higher risk for sunburns. Perception of high barriers to sun protection was the strongest modifiable correlate of sun protection.

Conclusions: Interventions to improve sun protection and reduce sun exposure and sunburns in high-risk children are needed.

Impact: Intervening in high-risk populations may help reduce the burden of melanoma in the United States. Cancer Epidemiol Biomarkers Prev; 24(1); 169–77. ©2015 AACR.
Ewing's Sarcoma: Dural Metastases after Intracranial Hemorrhage
Authors: Oz Ibrahim I. , Serifoglu Ismail , Bozay Oz Evrim , Piskin Etem , Edebali Nurullah
Published: January 2015

Ewing's sarcoma (ES) is a primary malignant tumor of the mesenchymal tissue of bone in children and young adults. Central nervous system metastases of ES are rarely seen. In this paper, we report a case of ES that progressed with dural metastases after spontaneous intracerebral hemorrhage.
Estimating the Endotracheal Tube Insertion Depth in Newborns Using Weight or Gestation: A Randomised Trial
Authors: Flinn Aisling M. , Travers Colm P. , Laffan Eoghan E. , O''Donnell Colm P.F.
Published: January 2015

Background: When intubating newborns, clinicians aim to place the tip of the endotracheal tube (ETT) in the mid-trachea. Clinicians usually estimate the ETT insertion depth based on weight. ETT tips are often incorrectly positioned in newborns. Estimating the insertion depth based on gestation may be more accurate. Objective: To determine whether estimating the ETT insertion depth using gestation, compared to weight, results in more correctly placed ETTs. Methods: Newborn infants without congenital anomalies who were intubated orally were randomised to having their ETT insertion depth estimated using weight [insertion depth (cm) = weight (kg) + 6] or gestation [value determined from a table]. The primary outcome was correct ETT position, defined as an ETT tip between the upper border of the first thoracic vertebra (T1) and the lower border of the second thoracic vertebra (T2) on a chest X-ray. The primary outcome was determined by one paediatric radiologist who was masked to group assignment. Results: Ninety infants were enrolled and the groups were well matched. The proportion of correctly placed ETTs was not significantly different between the groups [weight, 25/49 (51%), vs. gestation, 16/41 (39%), p = 0.293]. We found no significant differences in the secondary outcomes measured. Conclusion: Estimating the ETT insertion depth in newborns using gestation compared to weight did not result in more correctly placed ETTs.
PLA2G10
Gene Variants, sPLA2 Activity, and Coronary Heart Disease Risk
Authors: Guardiola Montse , Exeter Holly J. , Perret Claire , Folkersen Lasse , van’t Hooft Ferdinand , Eriksson Per , Franco-Cereceda Anders , Paulsson-Berne Gabrielle , Palmen Jutta , Li KaWah , Cooper Jackie A. , Khaw Kay-Tee , Mallat Ziad , Ninio Ewa , Karabina Sonia-Athina , Humphries Steve E. , Boekholdt S. Matthijs , Holmes Michael V. , Talmud Philippa J.
Published: January 2015

Background—

Observational studies report that secretory phospholipase A2 (sPLA2) activity is a marker for coronary heart disease (CHD) risk, and activity measures are thought to represent the composite activity of sPLA2-IIA, -V, and -X. The aim of this study was to use genetic variants of
PLA2G10
, encoding sPLA2-X, to investigate the contribution of sPLA2-X to the measure of sPLA2 activity and coronary heart disease (CHD) risk traits and outcome.

Methods and Results—

Three
PLA2G10
tagging single-nucleotide polymorphisms (rs72546339, rs72546340, and rs4003232) and a previously studied
PLA2G10
coding single-nucleotide polymorphism rs4003228, R38C, were genotyped in a nested case: control cohort drawn from the prospective EPIC-Norfolk Study (2175 cases and 2175 controls). Meta-analysis of rs4003228 (R38C) and CHD was performed using data from the Northwick Park Heart Study II and 2 published cohorts AtheroGene and SIPLAC, providing in total an additional 1884 cases and 3119 controls. EPIC-Norfolk subjects in the highest tertile of sPLA2 activity were older and had higher inflammatory markers compared with those in the lowest tertile for sPLA2 activity. None of the
PLA2G10
tagging single-nucleotide polymorphism nor R38C, a functional variant, were significantly associated with sPLA2 activity, intermediate CHD risk traits, or CHD risk. In meta-analysis, the summary odds ratio for R38C was odds ratio=0.97 (95% confidence interval, 0.77–1.22).

Conclusions—

PLA2G10
variants are not significantly associated with plasma sPLA2 activity or with CHD risk.
Kinect-ed Piano
Authors: Gillian Nicholas , Nicolls Sarah
Published: January 2015

The authors describe a gesturally controlled improvisation system for an experimental pianist, developed over several laboratory sessions and used during a performance at the 2011 conference on New Interfaces for Musical Expression (NIME). They discuss the architecture and performative advantages and limitations of the system, and reflect on the lessons learned throughout its development.
Conversational Interaction in Interactive Dance Works
Authors: Johnston Andrew
Published: January 2015

This paper describes an interactive dance/physical theatre work entitled Encoded, which made use of motion capture techniques and real-time fluid simulations to create systems intended to support, stimulate and augment live performance. Preliminary findings from a qualitative study of performers’ experiences with the system raise a number of issues, including the challenges of creating theatrical meaning with interactive systems, using Contact Improvisation as a metaphor for engaging creative systems, and the impact that large-scale projections can have on performers’ engagement.
Islam beyond Democracy and State in Kyrgyzstan
Authors: Montgomery David W.
Published: January 2015

Much has been made of the importance of democracy to securing individual rights and the general advancement of a just society. The role of democracy in post-Soviet governance and the strength of the state, however, have been called into question on many counts. Both state and democratic structures have been supported by elites who have used the claims of democracy and state to combat, or at least constrain, governance rooted in Islam. The ideals of democracy and the state, however, are experienced differently by those who are secularists and those for whom religion is a lived category. In this piece, I concern myself with how Muslims experience democracy and the state in Kyrgyzstan and thus how many remain unseduced by the unfulfilled promises of political rhetoricians.
Microstructure and tensile properties of Al0.5CoCrCuFeNi alloys produced by simple rolling and annealing
Authors: Tsai C.-W. , Tsai M.-H. , Tsai K.-Y. , Chang S.-Y. , Yeh J.-W. , Yeh A.-C.
Published: January 2015

This study demonstrates that simply by rolling at ambient temperature, FCC type high entropy alloy Al0.5CoCrCuFeNi can be refined to have nanocrystalline structure and exhibits outstanding combination of strength and ductility. The yield strength and ultimate tensile strength are 1284 and 1344 MPa, respectively, in combination with an elongation of 7.6. After a short annealing at 900°C for 10 min, the elongation is doubled to 15.3 with a trade-off around 20 in strength. This excellent combination of strength and ductility is attributable to the activation of quasi-dynamic recrystallisation during cold work and the limited grain growth during 900°C annealing.
The relationship between fasting plasma citrulline concentration and small intestinal function in the critically ill
Authors: Poole Alexis , Deane Adam , Summers Matthew , Fletcher Janice , Chapman Marianne
Published: January 2015

Introduction

In this study, we aimed to evaluate whether fasting plasma citrulline concentration predicts subsequent glucose absorption in critically ill patients.

Methods

In a prospective observational study involving 15 healthy and 20 critically ill subjects, fasting plasma citrulline concentrations were assayed in blood samples immediately prior to the administration of a liquid test meal (1 kcal/ml; containing 3 g of 3-O-methylglucose (3-OMG)) that was infused directly into the small intestine. Serum 3-OMG concentrations were measured over the following 4 hours, with the area under the 3-OMG concentration curve (AUC) calculated as an index of glucose absorption.

Results

The groups were well matched in terms of age, sex and body mass index (BMI) (healthy subjects versus patients, mean (range) values: age, 47 (18 to 88) versus 49 (21 to 77) years; sex ratio, 60% versus 80% male; BMI, 25.2 (18.8 to 30.0) versus 25.5 (19.4 to 32.2) kg/m2). Compared to the healthy subjects, patients who were critically ill had reduced fasting citrulline concentration (26.5 (13.9 to 43.0) versus 15.2 (5.7 to 28.6) μmol/L; P < 0.01) and glucose absorption (3-OMG AUC, 79.7 (28.6 to 117.8) versus 61.0 (4.5 to 97.1) mmol/L/240 min; P = 0.05). There was no relationship between fasting citrulline concentration and subsequent glucose absorption (r = 0.28; P = 0.12).

Conclusions

Whereas both plasma citrulline concentrations and glucose absorption were reduced in critical illness, fasting plasma citrulline concentrations were not predictive of subsequent glucose absorption. These data suggest that fasting citrulline concentration does not appear to be a marker of small intestinal absorptive function in patients who are critically ill.
Saateks / Foreword
Authors: Tenjes Silvi , Pool Raili
Published: January 2015

Saateks / Foreword
The case for adding X-linked agammaglobulinemia to newborn screening
Authors: Roifman Chaim M.
Published: January 2015

X-linked agammaglobulinemia typically presents in infancy or childhood with microbial infections as a consequence of low to absent mature B cells and pan-hypogammaglobulinemia, caused by mutations in BTK. However, atypical presentation in some cases may delay the diagnosis as well as the implementation of appropriate replacement therapy.
Variation in Rotavirus Vaccine Coverage by Provider Location and Subsequent Disease Burden
Authors: Sahni Leila C. , Tate Jacqueline E. , Payne Daniel C. , Parashar Umesh D. , Boom Julie A.
Published: January 2015

BACKGROUND:

Rotavirus vaccines were introduced in the United States in 2006. Full-series coverage is lower than for other vaccines, and disease continues to occur. We examined variation in vaccine coverage among provider locations and correlated coverage with the detection of rotavirus in children who sought treatment of severe acute gastroenteritis (AGE).

METHODS:

Vaccine records of children enrolled in an AGE surveillance program were obtained and children were grouped by the location that administered each child’s 2-month vaccines. Cases were children with laboratory-confirmed rotavirus AGE; controls were children with rotavirus-negative AGE or acute respiratory infection. Location-level coverage was calculated using ≥1 dose rotavirus vaccine coverage among controls and classified as low (<40%), medium (≥40% to <80%), or high (≥80%). Rotavirus detection rates among patients with AGE were calculated by vaccine coverage category.

RESULTS:

Of controls, 80.4% (n = 1123 of 1396) received ≥1 dose of rotavirus vaccine from 68 locations. Four (5.9%) locations, including a NICU, were low coverage, 22 (32.3%) were medium coverage, and 42 (61.8%) were high coverage. In low-coverage locations, 31.4% of patients with AGE were rotavirus-positive compared with 13.1% and 9.6% in medium- and high-coverage locations, respectively. Patients with AGE from low-coverage locations had 3.3 (95% confidence interval 2.4–4.4) times the detection rate of rotavirus than patients with AGE from high vaccine coverage locations.

CONCLUSIONS:

We observed the highest detection of rotavirus disease among locations with low rotavirus vaccine coverage, suggesting that ongoing disease transmission is related to failure to vaccinate. Educational efforts focusing on timely rotavirus vaccine administration to age-eligible infants are needed.
The Present and Future of Oil and Gas in Canada
Authors: Sproule J.C. , Edgington A.N. , Cleland N.A.
Published: January 2015

The oil and gas industry in Canada is the largest single source of mineral income in the country, generating income in excess of one billion dollars every year. Oil and gas supply over 70 per cent of Canada's energy requirements. At its present level of development, the industry could supply the total domestic oil and gas demand, but, due to geographic, economic, industry and political considerations, outside sources supply a large percentage of the Canadian consumption. The large volume of Canadian oil and gas that is exported to the United States amounts to something less than the total imports.

In the future, Canadian energy requirements are expected to grow at 4 1/2 percent per year and the percentage supplied by oil and gas is expected to remain at the present level. This means that production will treble within the next 25 years.

The reserves needed to provide this rate of production will not all be developed in the Western Canada Sedimentary Basin, but will be found in the Arctic Islands Basin and the basins off the east and west costs of Canada. The Athabasca Oil Sands will also provide a significant share of future production.

The industry must continue to search for new markets in order to utilize the anticipated production capability. The most logical extensions are into the Montreal and Chicago areas, but Arctic and offshore production should also be able to compete in the world markets as a secure source of supply.
Calculation of temperature distribution and rheological properties of the lithosphere along transect II in the Western Carpathian-Pannonian Basin region
Authors: Dérerová Jana , Bielik Miroslav , Pašiaková Mariana , Kohút Igor , Hlavńová Petra
Published: January 2015

The temperature model of the lithosphere along transect II passing through the Western Carpathians and the Pannonian Basin has been calculated using 2D integrated geophysical modelling methodology. Based on the extrapolation of failure criteria, lithology and calculated temperature distribution, we derived the rheology model of the lithosphere in the area. Our results indicate a decrease of the lithospheric strength from the European platform and the Western Carpathians towards the Pannonian Basin. The largest strength can be observed within the upper crust which suggests rigid deformation in this part of the lithosphere. In the lithospheric mantle, strength almost disappears which allows us to assume that the ductile deformation dominates in this part of the lithosphere
Asbestos manufacturing plants in Poland
Authors: Wilk Ewa , Krówczyńska Małgorzata , Zagajewski Bogdan
Published: January 2015

The unique set of physical and chemical properties of asbestos has led to its many industrial applications, such as roof coverings, textiles, rope, cord and yarn, paper, friction and composition materials, household product, acid-resistant filters, packing, insulation, and certain types of lagging, amongst others. In Poland asbestos-containing products were manufactured from raw materials imported mainly from the former Soviet Union, with production launched at the beginning of 20th century. According to Annex 4 to the Act of 19 June 1997 on the prohibition of the use of asbestos-containing products, there were 28 asbestos manufacturing plants in Poland located in 11 provinces throughout the country. The current survey was undertaken to enable asbestos manufacturing plants to be arranged, described and divided in order to contribute to further surveys.
Band Structure of Photonic Crystals Fabricated by Two-Photon Polymerization
Authors: Rybin Mikhail , Shishkin Ivan , Samusev Kirill , Belov Pavel , Kivshar Yuri , Kiyan Roman , Chichkov Boris , Limonov Mikhail
Published: January 2015

We study theoretically the band-gap structures of several types of three-dimensional photonic crystals with the fcc lattice symmetry: synthetic opals, inverted yablonovite and woodpile. The samples of inverted yablonovite, inverted yablonovite with a glassy superstructure and woodpile are fabricated by two-photon polymerization through a direct laser writing technique, which allows the creation of complex three-dimensional photonic crystals with a resolution better than 100 nm. A material is polymerized along the trace of a moving laser focus, thus enabling the fabrication of any desirable three-dimensional structure by direct “recording” into the volume of a photosensitive material. The correspondence of the structures of the fabricated samples to the expected fcc lattices is confirmed by scanning electron microscopy. We discuss theoretically how the complete photonic band-gap is modified by structural and dielectric parameters. We demonstrate that the photonic properties of opal and yablonovite are opposite: the complete photonic band gap appears in the inverted opal, and direct yablonovite is absent in direct opal and inverted yablonovite.
Intention to Purchase Products under Volume Discount Scheme: A Conceptual Model and Research Propositions
Authors: Iranmanesh Mohammad , Jayaraman Krishnaswamy , Ismail Ishak
Published: January 2015

Many standard brands sell products under the volume discount scheme (VDS) as more and more consumers are fond of purchasing products under this scheme. Despite volume discount being commonly practiced, there is a dearth of research, both conceptual and empirical, focusing on purchase characteristics factors and consumer internal evaluation concerning the purchase of products under VDS. To attempt to fill this void, this article develops a conceptual model on VDS with the intention of delineating the influence of the purchase characteristics factors on the consumer intention to purchase products under VDS and provides an explanation of their effects through consumer internal evaluation. Finally, the authors discuss the managerial implications of their research and offer guidelines for future empirical research.
Offline and Online Customer Satisfaction in B2C Markets
Authors: Aquilani Barbara , Serpico Elsa , Silvestri Cecilia , Ruggieri Alessandro
Published: January 2015

The chapter by Aquilani, Serpico, Silvestri, and Ruggieri explores online and offline customer satisfaction in B2C markets. The authors emphasize that building strong relationships with customers is of even higher strategic relevance in dynamic and competitive environments implying that firms must continuously work towards ever higher levels of experienced customer satisfaction. The objectives of this conceptual work are threefold: (1) to review customer satisfaction studies in both offline and online environments and their relationships with customer relationship management both offline and online, (2) to analyze tools and methods already used to measure it, and (3) to propose a new and comprehensive theoretical framework that helps evaluate overall customer satisfaction. The framework considers both offline and online customer satisfaction antecedents, being aware of the different weight and effects they have on e-customer satisfaction. This depends on the context in which they have been created and previously applied to, as well as considering the website as a moderator in the relationship between offline antecedents of customer satisfaction (prior experience, brand, quality, price, etc.) and overall customer satisfaction. Thus, the latter would come from both offline antecedents of customers' satisfaction and website quality dimensions, namely information, services, and system quality.
Dynamical Software and the Derivative Concept
Authors: Dikovic Ljubica
Published: January 2015

Modern teaching trends impose the need of spending less time on the manipulative approach to differential and integral calculus, putting the accent on the conceptual understanding of the subject. This chapter presents the standard approach and method used to teach the derivative of a function and indicates some critical points in the teaching of the derivative, offering, at the same time, suggestions for overcoming them. As a supplement, the author gives e-resources that can make possible the implementation of a stimulating, visual, dynamic, and broadened method for teaching the derivative of a function.
Using Educational Computer Games for Science Teaching
Authors: Wu Ying-Tien
Published: January 2015

This study explored 21 elementary science teachers' experiences of and attitudes toward playing computer games, and their positions regarding using computer games in science teaching. Also, these teachers' perspectives, willingness, and relevant professional abilities of integrating educational computer games (ECGs) into their instruction were investigated. There were three stages of data collection in this study: tape-recorded pre-interviews, experiencing an ECG for science learning, and tape-recorded follow-up interviews. This study revealed that less than forty percent of the teachers had ever used computer games in their teaching. After experiencing the ECG in this study, most teachers recognized the educational essence of ECGs, and all of them were willing to integrate ECGs in their science classes. However, most of the teachers expressed poor understanding of ECGs and digital game-based learning, and recognized the significant role of specific pedagogical content knowledge and the need for computer skills.
Implementing the Understanding by Design Framework in Higher Education
Authors: Alhamisi Judy , Glimps Blanche Jackson , Okezie Chukwunyere E.
Published: January 2015

This chapter describes an organizational initiative to develop and implement the Understanding by Design (UbD) curriculum-planning framework to improve learning outcomes for teacher candidates and their students during clinical experiences and in their future classrooms. This case study explores a pedagogical approach that has met with success in working with teacher candidates. The focus is on a narrow range of knowledge, skills, and dispositions related to effective teaching in science education: the ability to design, plan, and implement curriculum. Curriculum design using the Understanding by Design (UbD) Framework is a high priority when moving from simply covering subject matter to ensuring deep understanding. Using “Backward Design” helped many teacher candidates develop skills to plan effective science curriculum, units, and lessons. The experiences of two teacher education programs in building teacher candidates' skills in planning and implementing science education curriculum using the UbD Framework are presented in this case study.
Collaboration Not Competition
Authors: Benton Cynthia J. , White Orvil L. , Stratton Susan K.
Published: January 2015

This chapter documents the development of a program for college faculty, public school teachers, graduate, and undergraduate students to pursue international travel, study, and teaching in Thailand. The program features collaboration among institutions, faculty colleagues, and school personnel focused particularly on science and mathematics education. The chapter reflects on the current methodological perspectives used to compare educational systems and the concomitant outcomes in workforce articulation. Details of expansion, development, and measurement of local, individual, and program success are provided and analyzed using current competitive international models. An alternative view of international relationships as collaborative learning opportunities is proposed.
English Language Learners' Online Science Learning
Authors: Terrazas-Arellanes Fatima E. , Knox Carolyn , Rivas Carmen , Walden Emily
Published: January 2015

English Learners may struggle when learning science if their cultural and linguistic needs are unmet. The Collaborative Online Projects for English Language Learners in Science project was created to assist English learners' construction of science knowledge, facilitate academic English acquisition, and improve science learning. The project is a freely available, online project-based, bilingual instructional website designed for English learners of Hispanic origin. The project website contains two units: Let's Help Our Environment and What Your Body Needs. To create these collaborative online projects, two constructivist approaches were combined: The Cognitive-Affective Theory of Learning with Media and Project-Based Learning. These approaches to science education were used as the basis for culturally and linguistically relevant science instruction, which was delivered within a collaborative, online instructional platform. Using a case study design, two teachers demonstrated implementation of the project with fidelity, and students showed statistically significant gains in science content assessments. The Collaborative Online Projects for English Language Learners in Science project provides educators with a strong model for creating instructional materials that support English learners' science learning by combining culturally-relevant, constructivist, collaborative projects using online, multimedia technology.
Pre-Service Teachers' Self-Efficacy and Attitudes toward Learning and Teaching Science in a Content Course
Authors: Smith-Walters Cindi , Barker Heather L.
Published: January 2015

Science teaching is approached with hesitation by many PreK-8 teachers. This chapter explores the research on attitudes toward science and learning science as well as the perceived science efficacy of elementary pre-service teachers. It also describes a content-based, pedagogically rich life science course for pre-service preK-8 teachers that incorporates active and interactive teaching techniques in lieu of the traditional science methods course. Using evidence from this project and other research studies, the chapter argues for the inclusion and modeling of these approaches when preparing teachers of science and proposes that this non-traditional approach for teaching content-based courses for preparing teachers be considered in place of traditional science methods courses.
The Research of Generation Algorithm of Frequent Itemsets in High-Dimensional Data
Authors: Jiang Qing Chao
Published: January 2015

In the mining of association rules, the generation of frequent itemsets is a key factor that influence the efficiency and performance of the algorithm. With the increase of data dimension, it is obvious that the traditional association rules mining algorithm can’t meet the demand of high dimensional data mining. On the basis of Apriori algorithm, we put forward Split Mtrix _Apriori algorithm in this paper. By generating the Boolean matrix of the database, Split Mtrix _Apriori algorithm decreased the times of scanning database when generating the frequent itemsets. With adopting grouping processing strategy in the Boolean matrix, the algorithm can still keep high efficiency in dealing with high-dimensional data.So Split Mtrix _Apriori improved the efficiency of association rule mining significantly.
The Effect of Isothermal Deformation Parameters on Abnormal Grain Growth of P/M Nickel-Base Superalloy
Authors: Fang Shuang , Zhang Min Cong , Dong Yun Peng , Wang Shu Yun
Published: January 2015

The samples with a length of 50mm and cross section area of 20mm2 were machined from extruded P/M Nickel-base superalloy billet and the isothermal deformation tests were carried out at constant strain rate in a vacuum environment using the Thermecmastor. All the samples were deformed to a true strain of 1.04 at deformation temperature 1070°C and 1100°C and strain rate 0.001s-1~1s-1 respectively. The result is the deformation strain rate determine the position and the deformation temperature determine the severity of abnormal grain growth (AGG). The initial grain size and dislocation density is not the only reason to AGG. The AGG is related the recrystallization nucleation process is inhibited in the heat treatment. The AGG region usually has more low energy and low migration rate boundary than other regions.
Research on the Relationship between Speed Control System and Electromechanical Oscillations
Authors: Zhu Ya Qing , Zhong Min , Ma Yu Jia , Pan Feng Ping , Shi Ling Ling , Pang Zhi Qiang
Published: January 2015

The system damping of electric power systems is influenced by factors of many aspects. In this paper, we analyzed the impact of speed control system on the damping of the whole system in consideration of the Pole-Zero Analysis. The result shows that simple speed control would damp the oscillation, while the power-frequency control would excite the oscillation. Furthermore, the effect of steam turbine response rate on the system damping is analyzed. The time constant of hydraulic servo-motor would determine the response rate of the steam turbine, and as a result, an inflection point exists on the curve which describes the relationship between hydraulic servo-motor time constant and system damping. The result demonstrates that the characteristics of system damping can be used in parameter debugging of steam turbine.
The Measurement of the Fatigue Crack-Tip Displacement and Strain Fields under High Frequency Resonant Loading Applying DIC Method
Authors: Gao Hong Li , Jiang Wei , Liu Huan , Zheng Huan Bin , Liu Hui
Published: January 2015

In order to measure the displacement and strain field in the fatigue crack tip area of CT specimens under high frequency resonant loading condition in the fatigue crack propagation test, a method based on the digital image correlation (DIC) and digital high-speed photography technology are proposed in this paper. First, a series of digital speckle images of CT specimen under sinusoidal alternating load were collected by digital high-speed photography equipment, the displacement and strain fields within the region of crack tip in each image were calculated by DIC. The sinusoidal changing strain curve has been obtained by the least square sine wave fitting method, and the characteristic parameters of sinusoidal strain are calculated, such as the amplitude, frequency, phase, mean load . The images of characteristic position in one stress cycle were obtained by comparing the fitted sine curve of strain with the corresponding speckle images. Finally, the dynamic strain gauge was used to measure the strain at crack tip point during one stress cycle, and the accuracy and feasibility of DIC method were verified by the experimental results. The study result presented in this paper will supply a foundation for exploring the crack propagation law and measuring the fatigue crack growth parameters under high frequency resonant loading condition further.
Computation of Exterior Acoustics Problems in Two Dimensions by Trefftz-Type Finite Elements
Authors: Stojek Małgorzata
Published: January 2015

The paper deals with the application of the so-called T-type finite elements [1] to the calculation of the exterior acoustic problems in two dimensions. The method is based on the use of asuitably truncated T-complete set of Trefftz functions over individual subdomains linked by means ofa least square procedure. The vertex singularities and the Sommerfeld radiation condition are readilyincorporated in the trial functions. In order to show the performance of the approach two examples ofcomputations for infinite cylinders (of circular and square cross section) are presented and comparedwith those obtained by means of h-adaptive FE method [2].
Analysis of Structure of Elements for Automotive Industry
Authors: Sońta Grzegorz , Dudek Agata , Selejdak Jacek , Ulewicz Robert
Published: January 2015

The paper presents the results of the structure and chemical composition of materials used to manufacture of gear wheel for the automotive industry. Analyzed gear wheel that is a part of one of the mechanical systems of an automotive vehicle was made of sinter Sint-D 32 in the technology of powder metallurgy and alloy structural steel for quenching and tempering 42CrMo4. The cause of the analysis was to research for an alternative material for sinter Sint-D 32 after identified low static strength according to the requirements applicable in the automotive industry. For the analysis were used standard test methods applicable in materials science. Based on microstructure and mechanical properties analysis performed according to requirements applicable in the automotive industry, the research found that steel 42CrMo4 is relevant material to be used in serial production for this particular gear wheel.
Coding and Decoding Device Design of Three-Value Quantum Computer
Authors: Liu Hai Yan
Published: January 2015

A quantum computer is the computer technology and the micro physical scientists will combine the technology achievements. Quantum computer is the processing of information by using the quantum properties of particle, a new concept quantum laws to control information transmission and processing of computer. Light has the advantages in space time parallel and high-frequency radiation, which makes the optical become the main target of research model the future of computers. This did not prevent the three valued logic calculus is still an important part of the three values of optical computer. It is precisely because the three value of optical code decoder and the three value, importance, ALU logic optical so, in three valued optical computer all the key parts, we firstly research the value of three logic optical light coding, decoder and a value of three.
The Anti-Vibration Design of the Ball Grid Array Solder Joint
Authors: You Fan , Huang Yong Guang , Li Ben
Published: January 2015

In order to improve the anti-vibration performance of the Ball Grid Array solder joints, its solid model is established in ANSYS. Analyzing the stress response under the shock and vibration environment by using the finite element method. Then discussing the stress response of solder joints with different diameters and different heights in the same shock and vibration environment of each location for providing the basis for anti-vibration design. The results show that the longer diameter and lower height solder joint is more favorable to improve its anti-vibration performance.
Design of an Ultra-Wideband Wilkinson Power Divider in Modern Electronic Engineering
Authors: Cao Xin , Tang Zong Xi
Published: January 2015

In this paper, an ultra-wideband Wilkinson power divider based on the quarter wavelength transformation is proposed. The proposed power divider utilizes the resonance property of the four stage quarter wavelength microstrip stubs to increase the isolation between the to output ports. As the measured results show that, the power divider has the insertion loss less than 1.3dB with the minimum isolation 15.4dB in the working frequency range from 1GHz to 5GHz. The simulated results and measured results are in good agreement and the proposed power divider can be applied in the communication systems in modern electronic engineering.
Forest Fire Prevention Video Data Transmission System Design Based on Wireless Mesh Network
Authors: Yang Liu Qing
Published: January 2015

For forest fire prevention video monitoring data collection requirements,making video data collecting transmission system design based on wireless mesh network;including design standards and principles,design solutions and wireless network video monitoring system design;On the use of standards,working frequency,network infrastructure, coverage solutions,link budget,frequency planning, equipment power supply,supporting transmission and AC design describes the design proposal,proposed overall solution on wireless mesh network digital video system and applied to practical forest fire prevention wireless network video monitoring system,and achieved practical application of research results.
Study of Resource Allocation Method of Communication Network in Dense Crowded Area
Authors: Tan Jing Jing , Pan Ning , Wang Ke
Published: January 2015

In the dense crowded area, the communication resource allocation method has a very broad application space in the communication research field. Therefore, an improved communication resource distribution method in the dense crowded area is proposed based on pheromone search algorithm. In the dense crowded area, the regional communication network is constructed, and the pheromone of each resource node is taken with initialization processing. The collection of communication resource allocation task is obtained, the execution time of task is calculated, and the communication channel is selected. According to the pheromone concentration, all the pheromones are updated. The optimal channel of optimized communication resource allocation is searched, and the algorithm is improved. The simulation results show that the improved algorithm is applied in the regional allocation of communication resources in crowded area, the communication time can be effectively reduced, and the utilization of communication resources is improved, it will have a prospect application value in practice.
Resource Allocation Scheme for Device-to-Device Communications Underlaying Cellular Networks to Maximize Overall Throughput
Authors: Kou Shuai Hua , Sun Jun , Shao Shi Xiang
Published: January 2015

In cellular networks, Device-to-Device (D2D) communications can improve spectral efficiency and increase overall throughput. However, D2D users may cause interference to the cellular users (CU) due to sharing resource with CUs. In this paper, we proposed a resource allocation scheme to maximize the system throughput while guaranteeing the quality-of-service (QoS) requirements of all communication links. The proposed scheme allows as many D2D pairs as possible to reuse resource and includes three steps. Firstly, an exhaustive search method is used to search out all the reuse combinations, in which all users share the same resource. Secondly, transmit power for each reuse combination is allocated. Lastly, a suboptimal but simple algorithm is proposed to select suitable reuse combinations in order to maximize the overall throughput. Simulation results show that the proposed scheme can significantly increase system throughput and D2D access rate.
The Analysis and Simulation of Contact Loss between Pantograph and Catenary on Electric Railway
Authors: Gao Yin Han , Wang Ju Xian , Yang Kai Yu , Wang Tian Hao , An Zhan Yang
Published: January 2015

Based on the classical Mayer-arc model, this paper establishes the equivalent circuit of traction network for AC25kV electric railway from the essence of contact loss discharge. The voltage waves of contact loss arc at different moments are obtained by MATLAB/simulink. Through the analysis, it can be confirmed that the EMI (electromagnetic interference) with broad band and high amplitude will appear at the moment the contact loss between pantograph and catenary happens. Finally, relevant measures are given to avoid the probability event of contact loss.
Programmable Logic Controller Program Design Method Research Based on PLC
Authors: Wang Li Wei
Published: January 2015

The working principle of Programmable Logic Controller (PLC) is introduced. Three kinds of PLC programming method, logic based method, function based method and Petri Net based method are emphasized. The example is also given. It also points out that function based PLC programming method is a practical engineering method.
An Asynchronous Multi-Channel MAC Protocol Based on Cooperation Mechanism in Vehicular AdHoc Network
Authors: Li Xin Yun , Tang Lun
Published: January 2015

To solve the problem of vehicle adhoc network reliability is not high and multi-channel hidden terminals, we propose a multi-channel MAC protocol CAMP(cooperation-based asynchronous multi-channel MAC protocol) based mechanism for asynchronous cooperation in VANET. CAMP add to cooperation mechanisms in asynchronous multi-channel environment, the proposed scheme nodes cooperation in order to obtain the channel state information and status information to other nodes, thus a good solution to the hidden terminal problem multichannel transmission process, to achieve high mobility environment under the reliable transmission of data. The simulation results show that CAMP has better performance than IEEE 1609.4 standard, AMCP protocol, AMCMAC protocol on collision probability of SCH, safety messages delivery ratio.
The Application and Development of IGCC Power Generation Technology in China
Authors: Wang Lei , Li Wen Yan , Song Ying
Published: January 2015

With the serious problems caused by environment distruction, the large attention was taken to environmental protection. The coal pollution as one of the critical problems isurgently need to solve. Integrated Gasification Combined Cycle (IGCC), an advanced clean coal power generation system, is a main hotspot in energy and power field all over the world. This paper mainly focuses on the technology, development trend and the problems of IGCC in Tianjin. The success of IGCC greatly enhances the international influence of our country in dealing with the global climate change,which also makes great significance in the development and storage of China's coal-fired power generation.
Matpower Based Power Flow Calculation with Grid-Connected Photovoltaic
Authors: Yang Yong , Wang Dong Tao , Yao Qing Mei , Cai Wen Zhen
Published: January 2015

Photovoltaic (PV) power generation is one of important direction of future energy development by most countries. The research on power flow calculation of power system with grid-connected photovoltaic generation based on Matpower is given in this paper. Firstly, a stochastic model of PV system is presented in the paper. Then, Matpower is used in the simulation of power flow for IEEE 57 node system. Simulation results of with PV generation and without PV generation in IEEE 57 node system are presented. Comparison between the results shows that adding PV generation in power system will have great influence on power flow of power system.
Research on the Variety Law of Time-Dependent Reliability Model of Picking Link Rod in Sewing Machine
Authors: Zhao Fu , Gong Yan Jue , Xin Hong Bing , Xiang Hui Yu , Meng Chun Ling , Zhang Yuan
Published: January 2015

The reliability of mechanical component is a time-varied process because the parameters such as operation condition, load, strength, are varied with time or the loading numbers. This paper builds the time-dependent reliability model when life is measured by the loading numbers. The variety-law of component’s reliability with the lifetime is derived from the built model and simulation of picking link rod used in sewing machine. It is shown that the time-dependent reliability model is effective and the reliability of component decreases obviously with the time and the increasing load standard deviation.
Mobile Maintenance Room of GIS Equipment at the Voltage Class of 220kV
Authors: Wei Gang , Xiao Min , Xia Heng Yi , Yao Lin , Tang Yue Lin
Published: January 2015

According to data about GIS breakdown maintenance in Maintenance Branch of State Grid Chongqing Electric Power Company during recent years, GIS accident of Chongqing Electric Power Company that happens every year is internal fault of local air chambers (such as breaker, PT and bus) in most cases. Once accident happens, a high requirement will be proposed for water prevention and damp prevention at the site during either on-site inspection for the accident cause or replacement for the damaged equipment. In order to effectively cover the first hole of the opened GIS air chamber and make the operation environment meet rain-proof and damp-proof requirements during internal examination for GIS air chamber, a design scheme of mobile GIS maintenance room is proposed in this paper. SF6 detection equipment as well as temperature and humidity examination equipment is installed in the maintenance room, so as to measure multiple parameters and to guarantee light transmission, ventilation and fire resistance. It is convenient for installation and disassembly, and the space can be adjusted. It is suitable for GIS equipment maintenance at the voltage class of 220kV.