bluuebunny/crossref_metadata_2025 huggingface dataset:
Decision Making and STS Education: Exploring Scientific Knowledge and Social Responsibility in Schools and Science Centers Through an Issues‐Based Approach
Authors: Pedretti Erminia
Published: March 2010

In an attempt to bridge scientific knowledge and social responsibility, an issues‐based approach to learning in science, technology and society (STS) education was adopted by a classroom teacher in concert with a science center. This school and nonschool focus on a socioscientific issue (mining) provides a rich context from which students and teachers can explore the multiple perspectives and complexities of controversy. In particular, the case study examines (a) how fifth‐ and sixth‐grade students interpret and reason through a controversial socioscientific issue (mining in this context), and (b) how school and nonschool environments can provide a supportive forum for dialogue and decision making around a contextualized issue. This research supports the claim that it is important for young children to develop skills of natural inquiry, critical thinking, and decision making about science and technology and the links to the world they encounter at an early age in their education.
Student Reactions to Standards‐Based Mathematics Curricula: The Interplay Between Curriculum, Teachers, and Students
Authors: Bay Jennifer M. , Beem John K. , Reys Robert E. , Papick Ira , Barnes David E.
Published: March 2010

As standards‐based mathematics curricula are used to guide learning, it is important to capture not just data on achievement but data on the way in which students respond to and interact in a standards‐based instructional setting. In this study, sixth and seventh graders reacted through letters to using one of two standards‐based curriculum projects (Connected Mathematics Project or Six Through Eight Mathematics). Letters were analyzed by class, by teacher, and by curriculum project. Findings suggest that across classrooms students were positive toward applications, hands‐on activities, and working collaboratively. The level of students' enthusiasm for the new curricula varied much from class to class, further documenting the critical role teachers play in influencing students' perceptions of their mathematics learning experiences. The results illustrate that, while these curricula contain rich materials and hold much promise, especially in terms of their activities and applications, their success with students is dependent on the teacher.
A Locally Based Science Mentorship Program For High Achieving Students: Unearthing Issues That Influence Affective Outcomes
Authors: Templin Mark A. , Doran Rodney L. , Engemann Joseph F.
Published: March 2010

Little is known about the impact of university‐situated science mentoring programs on the affect of high achieving high school students, and few science mentorship programs have been described. This study describes a university‐based summer science mentorship program designed to offer participants a challenging science research experience and identifies issues that influence the affective outcomes for participants. Interview data was collected from eight participants at the 2nd and 6th weeks of participation. Student responses were summarized and iteratively searched to identify patterns within the responses for each interview. It was found that mentors played a crucial role in framing the participants' experience and influencing their affect and that careful selection and timing of research projects was critical to participants' attitude of learning and accomplishment. The implications for science mentorship program developers and for research are discussed.
Analogies and Reconstruction of Probability Knowledge
Authors: Fast Gerald R.
Published: March 2010

The effectiveness of utilizing analogies to effect conceptual change in students' alternative probability concepts was investigated. Forty‐one senior high school mathematics students were engaged in a knowledge reconstruction process regarding their beliefs about common everyday probability situations, such as sports events or lotteries. The students were given situations similar to those shown in previous research to reveal alternative mathematical conceptions. They were also given analogous researcher‐generated anchoring situations that had been pretested and found to elicit mathematically acceptable responses. The cognitive dissonance produced by the conflicting responses motivated students to reconstruct their knowledge. The results of the investigation showed that analogies can be effective in producing a desired conceptual change in high school students' probability concepts.
Subtraction From a Historical Perspective
Authors: Ross Susan C. , Pratt‐Cotter Mary
Published: March 2010

The algorithms used for subtraction vary. In the United States, three different algorithms were used almost equally until the 1940s: the equal additions, the decomposition, and the Austrian method. After William Brownell modified the decomposition algorithm, the use of other algorithms was practically eliminated in mathematics textbooks. Today, some texts introduce the equal additions algorithm, but the decomposition is still the predominant algorithm. This article reviews the historical use of each of the three algorithms in the United States, discusses the modification to the decomposition algorithm, and gives a brief overview of the current status of subtraction algorithms.
The State of Readiness of Initial Level Preservice Middle Grades Science and Mathematics Teachers and Its Implications on Teacher Education Programs
Authors: Bischoff Paul J. , Hatch Douglas D. , Watford Lettie J.
Published: March 2010

The purpose of this study was to document through interview and videotaped data the current state of readiness of 10 preservice middle grade teachers, regarding their ability to plan, implement, and reflect on an integrated mathematics and science lesson. The results showed that only one student was successful in implementing a lesson that compared favorably to national standards. This student's lesson plan contained minimal pedagogical considerations and consisted primarily of notes emphasizing fine detail of distinction about the content of the lesson using her own examples. The lesson plan and post‐lesson‐plan interview data of the remaining students indicated an adherence to algorithmic learning, rote memorization, and procedural knowledge. There were numerous content errors in the plans, and these students orally described a lack of self‐confidence in their ability to teach this lesson successfully. The most successful student demonstrated her competence in meeting standards of pedagogical content knowledge and was most successful in analyzing her own teaching. The results showed that most subjects of this study needed extensive training in content and pedagogy and in synthesizing these in a way consistent with modern learning theory.
Gender Differences in Science Achievement: Differential Effect of Ability, Response Format, and Strands of Learning Outcomes
Authors: Dimitrov Dimiter M.
Published: March 2010

The purpose of this study was to determine patterns of gender differences in science achievement of fifth graders, taking into account the role of ethnicity, ability, response format, and strands of learning outcomes. The results indicated that the gender differences in science achievement did not depend on ethnicity. However, response format, ability, and strands of learning outcomes had differential effects on student performance. In particular, at the high ability level boys did better than girls on the open‐ended format in physical sciences, but there were no gender differences in nature of science, earth and space sciences, and life sciences. There were no gender differences in science achievement for the low and medium ability students. Regardless of gender, the largest achievement gaps between the low, medium, and high ability students were on the open‐ended format in physical sciences.
Assessing Students' Understanding of Functions in a Graphing Calculator Environment
Authors: Beckmann Charlene E. , Thompson Denisse R. , Senk Sharon L.
Published: March 2010

In a classroom environment in which continual access to graphing calculators is assumed, items that have been used to assess students' understanding of functions often are no longer appropriate. This article describes strategies for modifying such items, including requiring students to explain their reasoning, using calculator‐active items, analyzing graphs and tables, and using real contexts.
Building Teacher‐Scientist Partnerships: Teaching About Energy Through Inquiry
Authors: Caton Elaine , Brewer Carol , Brown Fletcher
Published: March 2010

This study evaluated the effectiveness of teacher‐scientist partnerships for increasing the use. of inquiry in precollege classrooms. It assessed the influence of the Teaching About Energy Through Inquiry Institutes for middle and high school teachers and energy scientists on participants' attitudes about science and science education, use of inquiry instructional techniques, and student attitudes about their classroom environments. Participant surveys, institute and classroom observations, lesson plans, and interviews indicated increased appreciation for inquiry, greater confidence in teaching using inquiry, and greater use of inquiry in the classroom. Student surveys and classroom observations pointed to higher levels of student satisfaction and less friction among classmates during inquiry‐based investigations implemented after the institutes. Moreover, scientist partners reported increased familiarity with principles of science education and best teaching practice, which are essential skills and knowledge for disseminating results of scientific research to nonscientific audiences, as well as their own students. These results suggest that collaborations between teachers and research scientists can positively affect the environment for learning science in precollege and college classes. Successful collaborations are most likely to occur when equal status for teachers and scientists in the partnership is stressed and partners have the opportunity to explore inquiry‐based curricula together.
Mathematical Literacy and Abstraction in the 21st Century
Authors: Dubinksy Ed
Published: March 2010

Ed Dubinsky received his Ph.D. in mathematics from the University of Michigan in 1962 and for the next 25 years engaged in research in theoretical mathematics. In the mid‐80′s he became interested in mathematics education and has worked exclusively in the area since then. In his research, he tries to understand how a person's mind might be working when he or she tries to understand mathematical concepts at the postsecondary level. Based on this research, he has conducted large‐scale curriculum development projects in calculus, discrete mathematics, abstract algebra and cooperative learning. He has been editor or co‐editor of UME Trends, Research in Collegiate Mathematics Education, and the Journal of Computers in Mathematics and Science Teaching. He has held faculty positions at 8 universities in 5 countries on 3 continents: Fourah Bey College (Sierra Leone), University of Ghana, Tulane University, McMaster University, Polish Academy of Sciences, Clarkson University, Purdue University, and Georgia State University. Dr. Dubinsky is presently retired and consults with several universities on education matters.
Earth Vision 2000: Examining Students' Representations of Complex Data Sets
Authors: Vellom R. Paul , Pape Stephen J.
Published: March 2010

Graphic representations are powerful tools used by scientists and other professionals to help them understand multifaceted natural phenomena. They can also serve teachers and students as they attempt to understand complex data sets. This study examines pencil‐and‐paper graphs produced by students at the beginning of a 1‐week summer teacher/student institute, as well as computer‐based graphs produced by the same students at the end of the institute. Initial problems with managing the data set and producing meaningful graphs disappeared quickly as students used a process of “building up” to handle the complexity of web‐based data on water quality. This process is examined, as are findings from the institute related to (a) barriers to accessing web‐based data, (b) students' problem‐solving processes, and (c) the promise of this approach for learning about environmental science issues.
Graphical Representations of Speed: Obstacles Preservice K‐8 Teachers Experience
Authors: Billings Esther MH , Klanderman David
Published: March 2010

This study examines the difficulties college students experience when creating and interpreting graphs in which speed is one of the variables. Nineteen students, all preservice elementary or middle school teachers, completed an upper‐level course exploring algebraic concepts. Although all of these preservice teachers had previously completed several mathematics courses, including calculus, they demonstrated widespread misconceptions about the variable speed. This study identifies four cognitive obstacles held by the students, provides excerpts of their graphical constructions and verbal interpretations, and discusses potential causes for the confusion. In particular, misconceptions arose when students interpreted the behavior and nature of speed within a graphical context, as well as in situations where they were required to construct a graph involving speed as a variable. The study concludes by offering implications for the teaching and learning of speed and its interpretation within a graphical setting.
On the birational p-adic section conjecture
Authors: Pop Florian
Published: March 2010

In this article we introduce and prove a ℤ/p meta-abelian form of the birationalp-adic section conjecture for curves. This is a much stronger result than the usual p-adic birational section conjecture for curves, and makes an effective p-adic section conjecture for curves quite plausible.
Including Physiologically Based Nonlinearity in a Cochlear Model
Authors: Jiang Xiaoai , Grosh Karl
Published: March 2010

The outer hair cell (OHC) is known to be the main source of nonlinear activity in the cochlea. In this work, we used a one-dimensional fluid model of the cochlea coupled to a nonlinear model of the mechanical to electric coupling of the OHC and the basilar membrane (BM). The nonlinearity arises from the electromotility and the voltage-dependent stiffness of the OHC, and from the displacement dependence of the conductance of the stereocilia. We used a reciprocal nonlinear piezoelectric model of the OHC in combination with a model of stereocilia conductance depending on BM displacement (which resulted in a nonlinear circuit model). The mechanical properties of the various components of the model were motivated from physiological components of the cochlea. Simulations showed realistic gains in the activity, response saturation at high force level, and two-tone forcing generated distortion products while the shape of the filtering function was not as accurately replicated. We conclude that a cochlear model with a simple 1D fluid representation in combination with nonlinear OHC-stereocilia electromechanical response characteristic qualitatively predicts the compression property of the cochlea and can be used as a tool to investigate the relative importance of the various nonlinearities.
Added-Mass Effect in Modeling of Cilia-Based Devices for Microfluidic Systems
Authors: Kongthon J. , McKay B. , Iamratanakul D. , Oh K. , Chung J.-H. , Riley J. , Devasia S.
Published: March 2010

This article shows that the added mass due to fluid-structure interaction significantly affects the vibrational dynamics of cilia-based (vibrating cantilever-type) devices for handling microscale fluid flows. Commonly, the hydrodynamic interaction between the cilia-based actuators and fluid is modeled as a drag force that results in damping of the cilia motion. Our main contribution is to show that such damping effects cannot explain the substantial reduction in the resonant-vibrational frequency of the cilia actuator operating in liquid when compared with the natural frequency of the cilia in air. It is shown that an added-mass approach (that accounts for the inertial loading of the fluid) can explain this reduction in the resonant-vibrational frequency when operating cantilever-type devices in liquids. Additionally, it is shown that the added-mass effect can explain why the cilia-vibration amplitude is not substantially reduced in a liquid by the hydrodynamic drag force. Thus, this article shows the need to model the added-mass effect, both theoretically and by using experimental results.
Nonlinear Forced Vibrations of Laminated Piezoelectric Plates
Authors: Tanveer Muhammad , Singh Anand V.
Published: March 2010

A numerical approach is presented for linear and geometrically nonlinear forced vibrations of laminated composite plates with piezoelectric materials. The displacement fields are defined generally by high degree polynomials and the convergence of the results is achieved by increasing the degrees of polynomials. The nonlinearity is retained with the in-plane strain components only and the transverse shear strains are kept linear. The electric potential is approximated layerwise along the thickness direction of the piezoelectric layers. In-plane electric fields at the top and bottom surfaces of each piezoelectric sublayer are defined by the same shape functions as those used for displacement fields. The equation of motion is obtained by the Hamilton’s principle and solved by the Newmark’s method along with the Newton–Raphson iterative technique. Numerical procedure presented herein is validated by successfully comparing the present results with the data published in the literature. Additional numerical examples are presented for forced vibration of piezoelectric sandwich simply supported plates with either a homogeneous material or laminated composite as core. Both linear and nonlinear responses are examined for mechanical load only, electrical load only, and the combined mechanical and electrical loads. Displacement time histories with uniformly distributed load on the plate surface, electric volts applied on the top and bottom surfaces of the piezoelectric plates, and mechanical and electrical loads applied together are presented in this paper. The nonlinearity due to large deformations is seen to produce stiffening effects, which reduces the amplitude of vibrations and increases the frequency. On the contrary, antisymmetric electric loading on the nonlinear response of piezoelectric sandwich plates shows increased amplitude of vibrations.
Positioning of Deadeners for Vibration Reduction in Vehicle Roof Using Embedded Sensitivity
Authors: Reis Danilo Bruneli , Nicoletti Rodrigo
Published: March 2010

The noise, vibration and harshness (NVH) performance of passenger vehicles strongly depends on the fluid-structure interaction between the air in the vehicle cavity and the sheet metal structure of the vehicle. Most of the noise and vibration problems related to this interaction come from resonance peaks of the sheet metal, which are excited by external forces (road, engine, and wind). A reduction in these resonance peaks can be achieved by applying bitumen damping layers, also called deadeners, in the sheet metal. The problem is where these deadeners shall be fixed, which is usually done in a trial-and-error basis. In this work, one proposes the use of embedded sensitivity to locate the deadeners in the sheet metal of the vehicle, more specifically in the vehicle roof. Experimental frequency response functions (FRFs) of the roof are obtained and the data are processed by adopting the embedded sensitivity method, thus obtaining the sensitivity of the resonance peaks on the local increase in damping due to the deadeners. As a result, by examining the sensitivity functions, one can find the optimum location of the deadeners that maximize their effect in reducing the resonance peaks of interest. After locating the deadeners in the optimum positions, it was possible to verify a strong reduction in resonance peaks of the vehicle roof, thus showing the efficiency of the procedure. The main advantage of this procedure is that it only requires FRF measurements of the vehicle in its original state not needing any previous modification of the vehicle structure to find the sensitivity functions.
A Comparative Study on the Local Mean Decomposition and Empirical Mode Decomposition and Their Applications to Rotating Machinery Health Diagnosis
Authors: Wang Yanxue , He Zhengjia , Zi Yanyang
Published: March 2010

Health diagnosis of the rotating machinery can identify potential failure at its early stage and reduce severe machine damage and costly machine downtime. In recent years, the adaptive decomposition methods have attracted many researchers’ attention, due to less influences of human operators in the practical application. This paper compares two adaptive methods: local mean decomposition (LMD) and empirical mode decomposition (EMD) from four aspects, i.e., local mean, decomposed components, instantaneous frequency, and the waveletlike filtering characteristic through numerical simulation. The comparative results manifest that more accurate instantaneous frequency and more meaningful interpretation of the signals can be acquired by LMD than by EMD. Then LMD and EMD are both exploited in the health diagnosis of two actual industrial rotating machines with rub-impact and steam-excited vibration faults, respectively. The results reveal that LMD seems to be more suitable and have better performance than EMD for the incipient fault detection. LMD is thus proved to have potential to become a powerful tool for the surveillance and diagnosis of rotating machinery.
Experimental Validation of a Hybrid Electrostrictive Hydraulic Actuator Analysis
Authors: Chaudhuri Anirban , Wereley Norman M.
Published: March 2010

The basic operation of smart material-based hybrid electrohydraulic actuators involves high frequency bidirectional length change in an active material stack (or rod) that is converted to unidirectional motion of a hydraulic fluid by a set of valves. In this study, we present the design and measured performance of a compact hybrid actuation system driven by the single-crystal electrostrictive material PMN-32%PT. The active material was actuated at different frequencies with variations in the applied voltage, fluid bias pressure, and external load to study the effects on output velocity. The maximum actuator velocity was 330 mm/s and the corresponding flow rate was 42.5 cc/s; the blocked force of the actuator was 63 N. The results of the experiments are presented and compared with simulation data to validate a nonlinear time-domain model. Linearized equations were used to represent the active material while the inertia, viscous losses, and compressibility of the fluid were included using differential equations. Factors affecting system performance are identified and the inclusion of fluid inertia in the model is also justified.
Energy Harvesting From Vibrations With a Nonlinear Oscillator
Authors: Barton David A. W. , Burrow Stephen G. , Clare Lindsay R.
Published: March 2010

In this paper, we present a nonlinear electromagnetic energy harvesting device that has a broadly resonant response. The nonlinearity is generated by a particular arrangement of magnets in conjunction with an iron-cored stator. We show the resonant response of the system to both pure-tone excitation and narrow-band random excitation. In addition to the primary resonance, the superharmonic resonances of the harvester are also investigated and we show that the corresponding mechanical upconversion of the excitation frequency may be useful for energy harvesting. The harvester is modeled using a Duffing-type equation and the results are compared with the experimental data.
Vibration of a Segmented Heavy Column
Authors: Wang C. Y.
Published: March 2010

The vibration of a standing (or hanging) segmented column, affected by its own weight, is studied. The governing difference equations are solved numerically. The results tend to those of the continuous column as the number of segments tends to infinity. For the finite number of segments, the linear relation between frequency squared and self weight does not hold as in the continuous case.
Parametric Design of a Waterjet Pump by Means of Inverse Design, CFD Calculations and Experimental Analyses
Authors: Bonaiuti Duccio , Zangeneh Mehrdad , Aartojarvi Reima , Eriksson Jonas
Published: March 2010

The present paper describes the parametric design of a mixed-flow water-jet pump. The pump impeller and diffuser geometries were parameterized by means of an inverse design method, while CFD analyses were performed to assess the hydrodynamic and suction performance of the different design configurations that were investigated. An initial pump design was first generated and used as baseline for the parametric study. The effect of several design parameters was then analyzed in order to determine their effect on the pump performance. The use of a blade parameterization, based on inverse design, led to a major advantage in this study, because the three-dimensional blade shape is described by means of hydrodynamic parameters, such as blade loading, which has a direct impact on the hydrodynamic flow field. On the basis of this study, an optimal configuration was designed with the aim of maximizing the pump suction performance, while at the same time, guaranteeing a high level of hydrodynamic efficiency, together with the required mechanical and vibrational constraints. The final design was experimentally tested, and the good agreement between numerical predictions and experimental results validated the design process. This paper highlights the contrasting requirements in the pump design in order to achieve high hydrodynamic efficiency or good cavitation performance. The parametric study allowed us to determine design guidelines in order to find the optimal compromise in the pump design, in cases where both a high level of efficiency and suction performance must simultaneously be achieved. The design know-how developed in this study is based on flow field analyses and on hydrodynamic design parameters. It has therefore a general validity and can be used for similar design applications.
Flow Force Analysis of a Variable Force Solenoid Valve for Automatic Transmissions
Authors: Lee Gee Soo , Sung Hyung Jin , Kim Hyun Chul , Lee Hyun Woo
Published: March 2010

Three-dimensional numerical simulations were carried out to investigate the flow dynamic behavior and pressure characteristics of a variable force solenoid (VFS) valve used in automatic transmissions. To visualize the dynamic movement of the spool, a moving mesh with dynamic layering meshes for varying boundary conditions was employed. Relevant experiment was performed to validate the simulations. The VFS valve was characterized by determining the variation in the equivalent orifice area with the spool displacement. The pressure sensitivity was found to be precisely controlled by the relation between the depth and the area of the notch in the range of the characteristic length of the valve. The results of model C, which takes into account both seal leakage and notches, indicate that there are linear pressure sensitivities in the range of the valve overlap and that there are smooth pressure control characteristics in the range of the two notches. The VFS valve with a spool was shown to have an unavoidable and unique hysteresis, which is caused by the nonlinear electromagnetic forces at the end of strokes of the spool and by the friction forces in the valve overlap. The effects of varying the oil temperature on the pressure sensitivity curves and the seal leakage flow rates were also examined.
Development Length Requirements for Fully Developed Laminar Pipe Flow of Yield Stress Fluids
Authors: Poole R. J. , Chhabra R. P.
Published: March 2010

In this technical brief, we report the results of a systematic numerical investigation of developing laminar pipe flow of yield stress fluids, obeying models of the Bingham-type. We are able to show that using a suitable choice of the Reynolds number allows, for high Reynolds number values at least, the development length to collapse to the Newtonian correlation. On the other hand, the development length remains a weak, nonmonotonic, function of the Bingham number at small values of the Reynolds number (Re≤40).
Asymptotic Generalizations of the Lockhart–Martinelli Method for Two Phase Flows
Authors: Muzychka Y. S. , Awad M. M.
Published: March 2010

The Lockhart–Martinelli (1949, “Proposed Correlation of Data for Isothermal Two Phase Flow, Two Component Flow in Pipes,” Chem. Eng. Prog., 45, pp. 39–48) method for predicting two phase flow pressure drop is examined from the point of view of asymptotic modeling. Comparisons are made with the Lockhart–Martinelli method, the Chisholm (1967, “A Theoretical Basis for the Lockhart-Martinelli Correlation for Two Phase Flow,” Int. J. Heat Mass Transfer, 10, pp. 1767–1778) method, and the Turner–Wallis (1969, One Dimensional Two Phase Flow, McGraw-Hill, New York) method. An alternative approach for predicting two phase flow pressure drop is developed using superposition of three pressure gradients: single phase liquid, single phase gas, and interfacial pressure drop. This new approach allows for the interfacial pressure drop to be easily modeled for each type of flow regime such as bubbly, mist, churn, plug, stratified, and annular, or based on the classical laminar-laminar, turbulent-turbulent, laminar-turbulent, and turbulent-laminar flow regimes proposed by Lockhart and Martinelli.
Circadian Gating of the Cell Cycle Revealed in Single Cyanobacterial Cells
Authors: Yang Qiong , Pando Bernardo F. , Dong Guogang , Golden Susan S. , van Oudenaarden Alexander
Published: March 2010

Cycle Entrainment

Cells manage many cyclic processes that must coordinate with each other for best cellular performance.

Yang
et al.

(p.
1522
) present a general theoretical framework that quantitatively describes coupled cyclic processes and then apply this to the interaction between the circadian and cell-division cycles in single cyanobacteria. Simultaneously tracking individual cell divisions and circadian phases and fitting the data with the model suggest that cell-cycle progression slows down dramatically during a specific circadian interval, whereas cell-cycle progression is independent of the cell-cycle phase.
Markets, Religion, Community Size, and the Evolution of Fairness and Punishment
Authors: Henrich Joseph , Ensminger Jean , McElreath Richard , Barr Abigail , Barrett Clark , Bolyanatz Alexander , Cardenas Juan Camilo , Gurven Michael , Gwako Edwins , Henrich Natalie , Lesorogol Carolyn , Marlowe Frank , Tracer David , Ziker John
Published: March 2010

A Fair Society

Many of the social interactions of everyday life, especially those involving economic exchange, take place between individuals who are unrelated to each other and often do not know each other. Countless laboratory experiments have documented the propensity of subjects to behave fairly in these interactions and to punish those participants deemed to have behaved unfairly.

Henrich
et al.

(p.
1480
, see the Perspective by

Hoff

) measured fairness in thousands of individuals from 15 contemporary, small-scale societies to gain an understanding of the evolution of trustworthy exchange among human societies. Fairness was quantitated using three economic games. Various societal parameters, such as the extent to which food was purchased versus produced, were also collected. Institutions, as represented by markets, community size, and adherence to a world religion all predict a greater exercise of fairness in social exchange.
The Climatic Signature of Incised River Meanders
Authors: Stark Colin P. , Barbour Jonathan R. , Hayakawa Yuichi S. , Hattanji Tsuyoshi , Hovius Niels , Chen Hongey , Lin Ching-Weei , Horng Ming-Jame , Xu Kai-Qin , Fukahata Yukitoshi
Published: March 2010

Messy Mountain Meandering

Predicting the influence of climate on landscapes is sometimes straightforward; for example, river deposits might grow with increased rainfall because erosion rates and sediment transport increase. However, long-term tectonic processes complicate the geomorphic signatures of more gradual climate-related phenomena that reconfigure landscapes. By correlating a decades-long record of typhoon rainfall in Japan with digital elevation models,

Stark
et al.

(p.
1497
) show that climate directly influences the extent of river meandering. When expanded to a larger region of the western North Pacific, this analysis revealed a strong climatic imprint on the landscape of humid mountainous areas. The region-wide analysis also revealed that underlying bedrock strength, as opposed to tectonic uplift, acts as a secondary control.
China, India, and the Environment
Authors: Bawa Kamaljit S. , Koh Lian Pin , Lee Tien Ming , Liu Jianguo , Ramakrishnan P. S. , Yu Douglas W. , Zhang Ya-ping , Raven Peter H.
Published: March 2010

Cooperation between China and India can curtail biodiversity loss, mitigate climate change, and reduce deforestation.
Transition-State Spectroscopy of Partial Wave Resonances in the F + HD Reaction
Authors: Dong Wenrui , Xiao Chunlei , Wang Tao , Dai Dongxu , Yang Xueming , Zhang Dong H.
Published: March 2010

Partial View

Skilled billiard players can easily predict how spinning of one ball will affect the trajectory of the second ball it strikes in a collision. In principle, quantum mechanics can be used to predict the analogous impact of the angular momentum of reagents on the outcome of a chemical reaction. In practice, however, observation of most chemical reactions—even in the confines of a molecular beam apparatus—encompasses a vast number of collisions over multiple angular momentum distributions.

Dong
et al.

(p.
1501
; see the Perspective by

Althorpe

) have honed their spectroscopic resolution sufficiently to distinguish the impact of subtle angular momentum variations on the reactivity of fluorine with hydrogen atoms. Their data agree with theory and reveal oscillating peaks in reaction probability, termed partial wave resonances.
Eliminating Turbulence in Spatially Intermittent Flows
Authors: Hof Björn , de Lozar Alberto , Avila Marc , Tu Xiaoyun , Schneider Tobias M.
Published: March 2010

Taming Turbulence

When fluid flows through a pipe, if the inertial forces are increased or the viscosity is decreased, the flow will become increasing noisy and will shift from being laminar to turbulent. Turbulence can be triggered by roughness in the pipe or other irregularities, which cause local eddies that grow into full-scale disruption of the otherwise smooth flow.

Hof
et al.

(p.
1491
; see the Perspective by

McKeon

) show that a continuous turbulent eddy, downstream, eliminates the growth of upstream disturbances and can prevent the overall flow from becoming turbulent. Unlike many other control methods, the energy cost for implementing this strategy is less than the benefit gained by maintaining a laminar flow.
Expanding the Repertoire of Shape Memory Alloys
Authors: Ma Ji , Karaman Ibrahim
Published: March 2010

An iron alloy may open up new applications for strong materials that are also capable of large reversible shape changes.
Programming to Forget
Delete
The Virtue of Forgetting in the Digital Age

by Viktor Mayer-Schönberger

Princeton University Press, Princeton, NJ, 2009. 251 pp. $24.95, £16.95. ISBN 9780691138619.
Authors: Dutton William
Published: March 2010

Mayer-Schönberger explores a range of concerns arising from the fact that information technology makes us less able to forget our pasts.
Setting the Trap for Reactive Resonances
Authors: Althorpe Stuart C.
Published: March 2010

A combined quantum mechanical calculation and molecular beam study has succeeded in detecting elusive metastable quantum states.
Science-Based Health Care
Authors: Zhu Chen
Published: March 2010

The provision of adequate health care is one of the major challenges for modern societies. It is an especially tough task in developing countries with limited resources and insufficient capacity. Obstacles are even encountered at the conceptual level: For example, a traditional misconception is that spending on health is a social burden, instead of being a strategic investment essential for each nation's socioeconomic development. According to economic analyses, health system innovations will not only improve livelihoods but also boost internal consumption and job opportunities. But these innovations cannot succeed without the strong support of science.
Budget Red Tape in Europe Brings New Delay to ITER
Authors: Clery Daniel
Published: March 2010

The projected start of the ITER fusion reactor in France looks set to slip by another 10 months. The new completion date is now November 2019.
Fresh Momentum for China's Science Juggernaut
Authors: Stone Richard
Published: March 2010

Science won high praise and a hefty budget boost at last week's meetings of the National People's Congress and the Chinese People's Political Consultative Conference. Central government spending on science and technology is slated to rise 8% to $24 billion in 2010.
The Nile Delta's Sinking Future
Authors: Bohannon John
Published: March 2010

Climate change and damming the Nile are threatening Egypt's agricultural oasis.
Lucky Glimpses of a Weirdly Wetter Moon
Authors: Kerr Richard A.
Published: March 2010

At the Lunar and Planetary Science Conference, scientists flying a ground-penetrating radar on India's Chandrayaan-1 lunar orbiter reported a distinctive radar signature from the interiors but not the surroundings of more than 40 small craters in the north polar region, suggesting ice.
Multiplexed Serologic Assay for Nine Anogenital Human Papillomavirus Types
Authors: Opalka David , Matys Katie , Bojczuk Paul , Green Tina , Gesser Richard , Saah Alfred , Haupt Richard , Dutko Frank , Esser Mark T.
Published: March 2010

A multiplexed human papillomavirus (HPV) immunoassay has been developed for the detection of human IgG antibodies to HPV type 6, 11, 16, 18, 31, 33, 45, 52, and 58 virus-like particle (VLP) types in serum following natural infection or immunization with VLP-based vaccines. The VLP antigens were covalently conjugated to carboxyl Luminex microspheres (MS) using a carbodiimide chemistry. Antibody (Ab) titers were determined in a direct binding format, in which an IgG1- to -4-specific, phycoerythrin (PE)-labeled monoclonal antibody (MAb) (HP6043) binds to human serum IgG antibodies. Pooled serum samples from rhesus macaques immunized with a 9-valent VLP-based vaccine served as the reference standard. The overall specificity of the assay was >99%, and the linearity (parallelism) of the assay was <7% per 10-fold dilution. Total assay precision was <19% across 3 different VLP-microsphere lots, 2 secondary antibody lots, and 2 different operators over a period of 3 weeks. Three different methods were used to evaluate serostatus cutoffs (SCO): (i) a clinical sensitivity/specificity analysis based on “likely negative” and “likely positive” samples from nonvaccinees, (ii) stringent upper tolerance limits on samples from “likely negatives,” and (iii) stringent upper tolerance limits from the same “likely negative” sample set after VLP adsorption. Depending on the method to set the serostatus cutoff, the percentage of seropositive samples at the month 48 time point following vaccination with the HPV 6/11/16/18 quadrivalent vaccine ranged from 70% to 100%. This assay has proven useful for measuring the levels of serum antibody to the nine HPV VLPs following natural infection or administration of VLP-based vaccines.
Identification of Immunodominant B- and T-Cell Combined Epitopes in Outer Membrane Lipoproteins LipL32 and LipL21 of
Leptospira interrogans
Authors: Lin Xu'ai , Zhao Jinfang , Qian Jing , Mao Yafei , Pan Jianping , Li Liwei , Peng Huiqin , Luo Yihui , Yan Jie
Published: March 2010

Leptospirosis is a serious infectious disease caused by pathogenic
Leptospira
. B- and T-cell-mediated immune responses contribute to the mechanisms of
Leptospira interrogans
infection and immune intervention. LipL32 and LipL21 are the conserved outer membrane lipoproteins of
L. interrogans
and are considered vaccine candidates. In this study, we identified B- and T-cell combined epitopes within LipL32 and LipL21 to further develop a novel vaccine. By using a computer prediction algorithm, two B- and T-cell combined epitopes of LipL21 and four of LipL32 were predicted. All of the predicted epitopes were expressed in a phage display system. Four epitopes, LipL21 residues 97 to 112 and 176 to 184 (LipL21
97-112
and LipL21
176-184
, respectively) and LipL32
133-160
and LipL32
221-247
of LipL32 were selected as antigens by Western blotting and enzyme-linked immunosorbent assay. These selected epitopes were also recognized by CD4
+
T lymphocytes derived from LipL21- or LipL32-immunized BALB/c (H-2
d
) mice and mainly polarized the immune response toward a Th1 phenotype. The identification of epitopes that have both B- and T-cell immune reactivities is of value for studying the immune mechanisms in response to leptospiral infection and for designing an effective vaccine for leptospirosis.
Consequences of Interference of Milk with Chemoattractants for Enzyme-Linked Immunosorbent Assay Quantifications
Authors: Rainard P.
Published: March 2010

Concentrations of the chemoattractants CXCL1, CXCL2, CXCL3, CXCL8, and C5a in milk were reduced by the preparation of milk whey by high-speed centrifugation or with rennet. About half of the chemoattractants (35 to 65%) were associated with the casein micelle sediment, except when whey was prepared by acidification. Consequently, quantification of chemoattractants should be carried out preferentially with skimmed milk samples or, whenever whey is needed, with acidic whey samples. The interference of milk or milk whey with the enzyme-linked immunosorbent assays (ELISAs) used to quantify the chemoattractants was moderate, as long as tetramethylbenzidine (TMB), not ABTS [2,2′-azino-bis-(3-ethylbenzthiazoline-sulfonate)], was used as the substrate of peroxidase. These considerations will help to assess more precisely a component of the immune response of the mammary gland to infection.
Should Blood Cultures Be Performed for Patients with Acute Prostatitis?
Authors: Etienne Manuel , Pestel-Caron Martine , Chapuzet Claire , Bourgeois Ingrid , Chavanet Pascal , Caron François
Published: March 2010

The diagnostic and prognostic values of blood cultures (BC) for 347 acute prostatitis inpatients were evaluated. BC were positive for 21% of patients and contributed to the microbiological diagnosis for 5%. Fever duration, length of hospitalization, use of an antibiotic combination, duration of antibiotic use, and urine bacterial titers increased when BC were positive.
Comparative Evaluation of an Automated Repetitive-Sequence-Based PCR Instrument versus Pulsed-Field Gel Electrophoresis in the Setting of a
Serratia marcescens
Nosocomial Infection Outbreak
Authors: Ligozzi Marco , Fontana Roberta , Aldegheri Marco , Scalet Giovanna , Lo Cascio Giuliana
Published: March 2010

A semiautomated, repetitive-sequence-based PCR (rep-PCR) instrument (DiversiLab system) was evaluated in comparison with pulsed-field gel electrophoresis (PFGE) to investigate an outbreak of
Serratia marcescens
infections in a neonatal intensive care unit (NICU). A selection of 36 epidemiologically related and 8 epidemiologically unrelated isolates was analyzed. Among the epidemiologically related isolates, PFGE identified five genetically unrelated patterns. Thirty-two isolates from patients and wet nurses showed the same PFGE profile (pattern A). Genetically unrelated PFGE patterns were found in one patient (pattern B), in two wet nurses (patterns C and D), and in an environmental isolate from the NICU (pattern G). Rep-PCR identified seven different patterns, three of which included the 32 isolates of PFGE type A. One or two band differences in isolates of these three types allowed isolates to be categorized as similar and included in a unique cluster. Isolates of different PFGE types were also of unrelated rep-PCR types. All of the epidemiologically unrelated isolates were of different PFGE and rep-PCR types. The level of discrimination exhibited by rep-PCR with the DiversiLab system allowed us to conclude that this method was able to identify genetic similarity in a spatio-temporal cluster of
S. marcescens
isolates.
Phages Harboring Specific Peptides That Recognize the N Protein of the Porcine Reproductive and Respiratory Syndrome Virus Distinguish the Virus from Other Viruses
Authors: Ren Xiaofeng , Wang Mingcui , Yin Jiechao , Li Guangxing
Published: March 2010

The aim of the current study was to develop a novel diagnostic test for detecting porcine reproductive and respiratory syndrome virus (PRRSV) using phage display technology. The N gene of PRRSV isolate HH08 was cloned following reverse transcription-PCR. Sequence comparison indicated that the N gene shared 96.4% homology to that of North American PRRSV (isolate VR2332) and 35.5% with that of European PRRSV (isolate LV), indicating that the PRRSV isolate was related to the North American PRRSV genotype. The bacterially expressed N protein was used as a target in a biopanning process using a phage display random peptide library. Seven phages expressing different peptides had a specific binding activity with the N protein. The putative binding motifs were identified by DNA sequencing. More importantly, the selected phages harboring specific peptides that recognize the N protein of PRRSV were able to efficiently distinguish PRRSV from other viruses in enzyme-linked immunosorbent assays.
Use of ChromID Extended-Spectrum β-Lactamase Medium for Detecting Carbapenemase-Producing
Enterobacteriaceae
Authors: Carrër Amélie , Fortineau Nicolas , Nordmann Patrice
Published: March 2010

ChromID extended-spectrum β-lactamase (ESBL) culture medium is routinely used for screening ESBL producers. This medium was tested for detecting carbapenemase-producing
Enterobacteriaceae
isolates from a collection of reference strains and compared to the CHROMagar KPC culture medium previously evaluated for detecting KPC-producing isolates. Producers of IMP-, VIM-, and KPC-type carbapenemases with high levels of resistance to cephalosporins and to carbapenems were detected at 1 × 10
1
CFU/ml. The OXA-48 producers were not detected on ChromID ESBL medium unless coexpressing ESBLs, whereas carbapenemase-producing isolates with MICs of <4 μg/ml were not detected on CHROMagar KPC medium.