bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural profile of ultra‐high molecular weight polyethylene in acetabular cups worn on hip simulators characterized by confocal Raman spectroscopy
Authors: Puppulin Leonardo , Kumakura Tsuyoshi , Yamamoto Kengo , Pezzotti Giuseppe 
Published: January 2011

AbstractWe applied a Raman confocal spectroscopic technique to quantitatively assess the structural features of two kinds of acetabular cups made of ultra‐high molecular weight polyethylene. We wanted to know whether polyethylene cups belonging to different generations, and thus manufactured by different procedures, possess different molecular structures and how those differences affected their wear resistance. Emphasis was placed on oxidation profiles developed along the cross‐sectional depth of the cups in the main wear zone developed during testing in a hip simulator. The micrometric lateral resolution of the laser beam, focused at surface or sub‐surface sectional planes, enabled the visualization of highly resolved microstructural property profiles, including crystalline and amorphous phase fractions. Oxidation profiles retrieved from polyethylene cups belonging to different generations greatly differed after wear testing. The highly cross‐linked polyethylene showed a lower degree of crystallinity and oxidation at an appreciably slower rate as compared to that belonging to an earlier generation. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:893–899
APCI/APPI for synthetic polymer analysis
Authors: Terrier P. , Desmazières B. , Tortajada J. , Buchmann W. 
Published: January 2011

AbstractModern mass spectrometry of synthetic polymers involves soft ionization techniques. Whereas matrix‐assisted laser desorption/ionization (MALDI) and electrospray (ESI) are employed routinely, atmospheric pressure chemical ionization (APCI) and more recently atmospheric pressure photoionization (APPI) are used to a lesser extent. However, these latter ionization methods coupled to liquid‐phase separation techniques create new opportunities for the characterization of polymers, especially for low molecular weight compounds or for the polymers that are poorly ionizable by the usual methods. After a part devoted to the description of classical MS methods employed for polymer analysis (MALDI, ESI, and their use with chromatography), APCI and APPI techniques will be described, discussed, and selected examples will present the interest of these ionization sources (or interfaces for LC/MS) in the field of polymer analysis. © 2011 Wiley Periodicals, Inc., Mass Spec Rev 30:854–874, 2011
Agglomerative connectivity constrained clustering for image segmentation
Authors: Li Jia 
Published: January 2011

AbstractWe consider the problem of clustering under the constraint that data points in the same cluster are connected according to a pre‐existed graph. This constraint can be efficiently addressed by an agglomerative clustering approach, which we exploit to construct a new fully automatic segmentation algorithm for color photographs. For image segmentation, if the pixel grid with eight neighbor connectivity is imposed as the graph, each group of pixels generated by this clustering method is ensured to be a geometrically connected region in the image, a desirable trait for many subsequent operations. To achieve scalability for images with large sizes, the segmentation algorithm combines the top‐downk‐means clustering with the bottom‐up agglomerative clustering method. We also find that it is advantageous to conduct clustering at multiple stages through which the similarity measure is adjusted. Experimental results with comparison to other widely used and state‐of‐the‐art segmentation methods show that the new algorithm achieves higher accuracy at much faster speed. A software package is provided for public access. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 84–99 2011
Exploring the complexity of tree thinking expertise in an undergraduate systematics course
Authors: Halverson Kristy L. , Pires Chris J. , Abell Sandra K. 
Published: January 2011

AbstractStudent understanding of biological representations has not been well studied. Yet, we know that to be efficient problem solvers in evolutionary biology and systematics, college students must develop expertise in thinking with a particular type of representation, phylogenetic trees. The purpose of this study was to understand how undergraduates make sense of phylogenetic representations presented in a plant systematics course designed to promote student tree thinking expertise. The primary data sources were two‐tiered pre/posttests and interviews with key informants. Using observations and document analysis as supporting data, we identified multiple misconceptions within students' knowledge of systematics not previously identified in the literature. Relying upon these misconceptions, students developed alternative types of reasoning that interfered with interpreting and using trees. We constructed a classification of student reasoning and identified a suite of varying levels of approaches that went beyond misreading the topology of phylogenetic trees to include the persistent use of nonevolutionary reasoning to address phylogenetic problems. We categorized student reasoning as extraneous, ecological, morphological, branch influenced, tree shape influenced, node influenced, limited phylogenetic, and phylogenetic. By better understanding our students reasoning by qualitative assessments, these findings have implications for curriculum, instruction, and assessment strategies. © 2011 Wiley Periodicals, Inc. Sci Ed 95:794–823, 2011
Formation of Peelable Rough Gold Patterns on an Ionic Liquid Template
Authors: Ohzono Takuya , Monobe Hirosato , Fukuda Nobuko , Fujiwara Masahiro , Shimizu Yo 
Published: January 2011

AbstractThe ability to control metal patterns at the micro‐ and nanoscales, along with the development of a simple fabrication method, is important to many applications in the fields of materials science, biological sensing, electronics, and photonics. Herein, a simple approach to fabricating gold micropatterns with controlled roughness is reported. In this approach, gold is evaporated onto a striped liquid micropattern formed on self‐organized microwrinkles. Gold nanoribbons with higher roughness form on the liquid part of the substrate because the deposited gold atoms can diffuse, grow, and aggregate at the liquid–air interface, whereas flat gold films form on the solid part. The rough gold nanoribbons formed on the liquid can then be peeled off through contact with water. The extinction spectrum of the rough gold nanoribbons suggests characteristic surface‐plasmon absorption. This shows the possibility of using rough gold nanoribbons with controlled shape in plasmonic technology.
Isolating bugs in multithreaded programs using execution suppression
Authors: Jeffrey Dennis , Wang Yan , Tian Chen , Gupta Rajiv 
Published: January 2011

AbstractMemory‐related program failures in multithreaded programs can be caused by a variety of bugs. Concurrency bugs can occur due to unexpected or incorrect thread interleavings during execution. Other kinds of memory bugs, such as buffer overflows and uninitialized reads, may also occur in multithreaded as well as single‐threaded programs. Most prior techniques for isolating these bugs are specialized, addressing only one type of concurrency bug or certain types of other memory bugs. The memory corruption caused by these bugs can also undergo significant propagation during program execution. When a program failure finally occurs due to memory corruption, the true root cause of the failure may be effectively concealed as significant portions of memory may have become corrupted. We propose a general framework that can isolate the root cause of any failure in a multithreaded program that involves memory corruption and reveals at least a subset of this memory corruption. This includes three important types of concurrency bugs—data races, atomicity violations, and order violations—as well as other kinds of memory bugs. To account for propagation of memory corruption, our approach uses a dynamic technique called ‘execution suppression’ that iteratively reveals memory corruption in a failing execution to isolate the true root cause of the failure. Copyright © 2011 John Wiley & Sons, Ltd.
College chemistry students' mental models of acids and acid strength
Authors: McClary LaKeisha , Talanquer Vicente 
Published: January 2011

AbstractThe central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research study involving students enrolled in different types of organic chemistry course sections at our university. Our analysis led to the identification of four distinct mental models, some of which resembled scientific models of acids and acid strength. However, the distinct models are better characterized as synthetic models that combined assumptions from one or more scientific models with intuitive beliefs about factors that determine the properties of chemical substances. For many students in our sample, mental models served more as tools for heuristic decision‐making based on intuitively appealing, but many times mistaken, concept associations rather than as cognitive tools to generate explanations. Although many research participants used a single general mental model to complete all of the interview tasks, the presence of specific problem features or changes in the nature of the task (e.g., prediction vs. explanation) prompted several students to change their mental model or to add a different mental representation. Our study indicates that properly diversifying and sequencing the types of academic tasks in which students are asked to participate could better foster meaningful learning as different types of cognitive resources may be activated by different students, and thus shared, analyzed, and discussed. © 2011 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 396–413, 2011
Study of a wireless multimodal sensing system integrated with an electrical conductivity sensor and a temperature sensor for the health control of cows
Authors: Futagawa Masato , Ishida Mitsuyoshi , Ishida Makoto , Sawada Kazuaki 
Published: January 2011

AbstractImproved technology for the real‐time, continuous monitoring of health of the animals is an important requirement for the animal production industry. We have studied a multimodal sensor consisting of integrated electrical conductivity (EC) and temperature sensors, a wireless unit, and some circuit boards. We measured the information relayed by the integrated sensor located at several positions within the first stomach (known as ‘the rumen’) in cows. The wireless unit was able to simultaneously monitor the EC and temperature sensors. The results of these tests showed that the developed unit is a useful tool, since the data obtained were reasonable. We then measured the RF field strength as a function of the distance between the wireless unit and the antenna. We calculated the performance that is required in terms of the received power to accurately transmit results from the rumen. We confirmed that the unit could achieve the necessary performance to send data from the rumen to the receiver. We could also find a criterion for the amount of RF power necessary for successful measurements from rumen. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Performance of DS‐UWB in MB‐OFDM and multi‐user interference over Nakagami‐mfading channels
Authors: Mehbodniya Abolfazl , Aïssa Sonia 
Published: January 2011

ABSTRACTThe mutual interference between the two ultra wideband (UWB) technologies, which use the same frequency spectrum, will be a matter of concern in the near future. In this context, we present a performance analysis of direct‐sequence (DS) UWB communication in the presence of multiband orthogonal frequency division multiplexing (MB‐OFDM) UWB interfering transmissions. The channel fading is modeled according to Nakagami‐m distribution, and multi‐user interference is taken into account. The DS‐UWB system performance is evaluated in terms of bit error rate (BER). Specifically, using the characteristic function approach, an analytical expression for the average BER is derived conditioned on the channel impulse response. Numerical and simulation results are provided and compared for different coexistence scenarios. Copyright © 2011 John Wiley & Sons, Ltd.
Pre‐filtering technique for MAI cancellation in MC‐CDMA systems
Authors: Chang Tain‐Sao , Yen Cherng‐Chang , Yang Ya‐Yin , Wen Jyh‐Horng 
Published: January 2011

ABSTRACTMulticarrier code division multiple access (MC‐CDMA), is a promising multiplexing technique for future communication systems. In this study, we employ the well‐known Walsh‐Hadamard spreading codes for synchronous downlink transmission of MC‐CDMA systems. The spreading codes allow that the frequency diversity to be efficiently exploited. However, multipath propagation may cause orthogonality among users is distorted, and this distortion produces multiple access interference (MAI). To eliminate this effect, we propose a pre‐filtering‐based MC‐CDMA system which uses a pre‐filtering technique at the transmitter and an equal gain combining (EGC) scheme at the receivers, respectively. Our proposed pre‐filtering technique transforms the transmitted signals so that the MAI can be eliminated, and the EGC scheme weights the signals received from all subcarriers so that channel distortions can be compensated. Furthermore, the proposed technique can calculate the transmitted power over all subcarriers to satisfy the required quality of service of each user and archive MAI‐free. In this paper, performance in terms of bit error rate is analyzed; in comparison with the EGC, orthogonal restoring combining, and maximal ratio combining schemes at receiver, respectively. Copyright © 2011 John Wiley & Sons, Ltd.
Connecting Youth Violence Prevention, Positive Youth Development, and Community Mobilization
Authors: Allison Kevin W. , Edmonds Torey , Wilson Karen , Pope Michell , Farrell Albert D. 
Published: January 2011

AbstractSeveral disconnects serve to weaken the use of evidence based programming in community settings. Communities face the need to address the challenges of multiple risk behaviors faced by adolescents in their communities, but must also work to support successful transitions to adulthood and the broader positive development of their youth. The stronger integration of positive youth development and prevention of youth risk at the community level may offer an opportunity to support the implementation and ongoing development of evidence‐based practices (EBPs). This article provides an overview of the VCU Clark‐Hill Institute for Positive Youth Development Institute's community mobilization effort in Richmond, Virginia and reports preliminary findings from our integrated mobilization efforts. First, we review the role of our Community Advisory Council in their collaborative work to support positive youth development and reduce risk for youth violence. Next, we present examples of institute efforts in providing technical assistance relevant to supporting the use and development of EBPs. We then discuss the adaptation of an evidence‐based program to target positive youth development. We also present overviews from qualitative investigations examining barriers and supports that inform and are relevant to the implementation of EBPs. Finally, we consider ways in which community efforts inform and shape institute efforts to develop EPBs. Taken together, these activities provide examples of how community‐based mobilization efforts can integrate and inform the implementation of EBPs and the role and use of prevention science as a tool in supporting effective programming to promote positive youth development and prevent youth violence.
Dual- and multi-energy CT: approach to functional imaging
Authors: Fornaro Juergen , Leschka Sebastian , Hibbeln Dennis , Butler Anthony , Anderson Nigel , Pache Gregor , Scheffel Hans , Wildermuth Simon , Alkadhi Hatem , Stolzmann Paul 
Published: January 2011

Abstract
The energy spectrum of X-ray photons after passage through an absorber contains information about its elemental composition. Thus, tissue characterisation becomes feasible provided that absorption characteristics can be measured or differentiated. Dual-energy CT uses two X-ray spectra enabling material differentiation by analysing material-dependent photo-electric and Compton effects. Elemental concentrations can thereby be determined using three-material decomposition algorithms. In comparison to dual-energy CT used in clinical practice, recently developed energy-sensitive photon-counting detectors sample the material-specific attenuation curves at multiple energy levels and within narrow energy bands; the latter allows the detection of element-specific, k-edge discontinuities of the photo-electric cross section. Multi-energy CT imaging therefore is able to concurrently identify multiple materials with increased accuracy. These specific data on material distribution provide information beyond morphological CT, and approach functional imaging. This article reviews the principles of dual- and multi-energy CT imaging, hardware approaches and clinical applications.
Urodynamic and clinical effects of transvaginal mesh repair for severe cystocele with and without urinary incontinence
Authors: Liang Ching‐Chung , Lin Yi‐Hao , Chang Yao‐Lung , Chang Shuenn‐Dhy 
Published: January 2011

AbstractObjectiveTo demonstrate the urodynamic and clinical effects of transvaginal polypropylene mesh repair (TVM) for severe cystocele with or without stress urinary incontinence (SUI).MethodsOne hundred women with severe cystocele who underwent transvaginal cystocele repair using a tension‐free polypropylene mesh were included in a retrospective study. A simultaneous transobturator tape (TOT) procedure was performed in 24 patients with concurrent urodynamic stress incontinence (USI). Postoperative follow‐up examinations included urodynamic testing, pelvic organ prolapse quantification, and urogynecologic questionnaire.ResultsMean follow‐up was 35 months (range, 13–68 months). At 3–6 months after surgery, 2 (8.3%) of the 24 patients with USI who had undergone TVM and TOT had persistent SUI. Of the 30 women with occult USI who had undergone TVM alone, 6 (20%) developed symptomatic SUI and 9 (30%) had asymptomatic SUI. Thirteen (28.3%) of the 46 patients without USI developed postoperative SUI. The 1‐year results showed de novo SUI in 10 (10%) women, recurrent cystocele in 6 (6%), and mesh erosions in 5 (5%). Four (13.3%) of the 30 patients engaging in sexual activity had dyspareunia.ConclusionTVM is effective and safe in patients with severe cystocele, but may have an impact on voiding and sexual activity.
Polycystic ovary syndrome and increased polyp numbers as risk factors for malignant transformation of endometrial polyps in premenopausal women
Authors: Kilicdag Esra B. , Haydardedeoglu Bulent , Cok Tayfun , Parlakgumus Ayse H. , Simsek Erhan , Bolat Filiz A. 
Published: January 2011

AbstractObjectiveTo determine the pre‐malignant and malignant potential of endometrial polyps and to assess whether different clinical parameters are associated with malignancy in the polyps of premenopausal women.MethodsThe clinical records of operative office hysteroscopic and resectoscopic procedures for endometrial polyps in 417 premenopausal women who attended Baskent University were examined over a retrospective period of 30 months. Only premenopausal patients were included in the study.ResultsIn 97.8% of women, histology showed benign endometrial pathology. In 2.2% of women, pre‐malignant or malignant conditions were found in the polyp. Polycystic ovary syndrome (PCOS) and the presence of 2 or more polyps were associated with significant pre‐malignant or malignant changes.ConclusionThe presence of irregular vaginal bleeding was not a predictor of malignancy in the polyp. Premenopausal women with PCOS and those with 2 or more polyps had an increased prevalence of polyp malignancy. These groups of patients, whether symptomatic or not, should be evaluated by hysteroscopic resection of the polyps.
The concept of cryo-conditioning in landscape evolution
Authors: Berthling Ivar , Etzelmüller Bernd 
Published: January 2011

AbstractRecent accounts suggest that periglacial processes are unimportant for large-scale landscape evolution and that true large-scale periglacial landscapes are rare or non-existent. The lack of a large-scale topographical fingerprint due to periglacial processes may be considered of little relevance, as linear process–landscape development relationships rarely can be substantiated. Instead, periglacial landscapes may be classified in terms of specific landform associations. We propose “cryo-conditioning”, defined asthe interaction of cryotic surface and subsurface thermal regimes and geomorphic processes, as an overarching concept linking landform and landscape evolution in cold regions. By focusing on the controls on processes, this concept circumvents scaling problems in interpreting long-term landscape evolution derived from short-term processes. It also contributes to an unambiguous conceptualization of periglacial geomorphology. We propose that the development of several key elements in the Norwegian geomorphic landscape can be explained in terms of cryo-conditioning.
Evolutionary diversification of bruchine beetles: climate-dependent traits and development associated with pest status
Authors: Tuda M. 
Published: January 2011

AbstractA number of insect species infest human households and stored foods and products, leading to their designation as pests. Until recently, little was known about the factors driving the evolution of pests that feed on stored dry foods. Here, I review the effects of changes in climate and species interactions on the evolution and ecology of beetles that feed on dried seeds/grains. My review focuses on evidence that the host utilization by part of the species in the subfamily Bruchinae (Chrysomelidae) is a preadaptation for utilizing stored dry seeds and grains, thus leading to their status as a pest. These and other stored product pest beetles retain a higher percentage of water in their body, relative to the water content of their diet, than beetles that feed on fresh crops. I review the studies that have documented adaptation, acclimation and polyphenetic response to high temperatures and desiccation and/or made direct comparisons between these traits between developmental stages, populations and among higher taxonomic groups. Finally, I review evidence for the effects of environmental change on insect host-parasitoid and competitor assemblages.