bluuebunny/crossref_metadata_2025 huggingface dataset:
Fastlane
Authors: van Lint J. W. C. , Hoogendoorn Serge P. , Schreuder Marco
Published: February 2009

The heterogeneity of traffic is a significant if not dominant factor in accurately modeling freeway traffic flow operations. For example, high truck percentages may induce congestion at much lower volumes, and hence different network traffic conditions may result than with low truck percentages. This implies that traffic models for real-time decision support systems in traffic management centers should provide the means to account for traffic heterogeneity. A new, multiclass, first-order traffic model is presented that provides these means and is implemented in the decision-support system BOSS-Offline, operational in all five highway traffic management centers in the Netherlands. FASTLANE differs from earlier multiclass first-order macroscopic traffic models in that it calculates the dynamics in terms of state-dependent (instead of constant) passenger-car equivalents, which is in line with both theory and empirical microscopic data. The model is numerically solved by an efficient and stable Godunov-based solver while maintaining a dynamic and realistic representation of class-specific flows and densities throughout the network. In two synthetic test cases and one based on real data, the workings of FASTLANE under different truck percentages and different conditions are demonstrated.
Estimating Individual Speed-Spacing Relationship and Assessing Ability of Newell's Car-Following Model to Reproduce Trajectories
Authors: Duret Aurélien , Buisson Christine , Chiabaut Nicolas
Published: February 2009

Capturing variability within flow is an important task for traffic flow models. The linearity of the congested part of the fundamental diagram induces a linear speed-spacing relationship at an individual level, characterized by two parameters. This study assumes that most intervehicle variability can be accounted for by estimating these two parameters for each vehicle. Two methods are presented to quantify individual linear speed-spacing relationships. The first method is based on data: it estimates the speed-spacing relationship by fitting the experimental speed-spacing scatter plot with a straight line. The second method is based on simulation: it computes the optimum parameters so that the simulated trajectories obtained by Newell's car-following algorithm reproduce as closely as possible the experimental vehicle's trajectories. Both proposed methods are implemented on the Next Generation Simulation trajectory data set recorded on I-80. The individual parameters for the speed-spacing relationship are quantified, and their distributions are specified. The need to distinguish driver behavior on a lane-by-lane basis is discussed. The results tend to prove that taking into account individual variability between drivers can improve the accuracy of simulated trajectories.
Asymptotic Stability and Vehicle Safety in Dynamic Car-Following Platoon
Authors: Tanaka Mitsuru , Ranjitkar Prakash , Nakatsuji Takashi
Published: February 2009

A vehicle in a platoon sometimes faces the risk of causing a rear-end collision when it is following a vehicle in front. The stability theory of the well-known General Motors car-following models says that the fluctuations of vehicle speeds and headways will increasingly propagate to the rear vehicle in a platoon if the platoon is asymptotically unstable. However, almost no research has been done to validate this phenomenon with the real car-following platoon data. Therefore, the car-following platoon data, including 10 vehicle trajectories, were used to evaluate asymptotic stability in the platoon. The asymptotic stability in vehicle safety is evaluated on the assumption that the vehicle in the rear position is exposed to riskier conditions than the vehicle positioned in front because of the shorter headways created by increased fluctuations of speeds and headways in a platoon if the asymptotic stability is unstable. Three indicators for safety are defined: potential danger time, impact speed, and expected impact speed. The outcomes in these safety indicators did not show that the car-following platoon was in asymptotically unstable conditions. Therefore, two supplemental indicators were defined to closely observe asymptotic stability: maximum speed amplitude and maximum spacing amplitude. These stability indicators were used to explain that the car-following platoon was under asymptotically unstable conditions. As a result, a hidden aspect of the relationship between asymptotic stability and vehicle safety was discovered in the real car-following platoon.
Modeling Driver Behavior as Sequential Risk-Taking Task
Authors: Hamdar Samer H. , Treiber Martin , Mahmassani Hani S. , Kesting Arne
Published: February 2009

Acceleration models are at the core of operational driving behaviors and include car-following models that capture interactions between a lead and following vehicles. The main assumption in these models is that the behavior of the following vehicle (e.g., change in acceleration) is related directly to a stimulus observed or perceived by the driver, defined relative to the lead vehicle (e.g., difference in speeds or headways). An important aspect missing from previous formulations pertains to the stochastic character of the cognitive processes used by drivers, such as perception, judgment, and execution while driving. A car-following model that reflects the psychological and cognitive aspects of the phenomenon and captures risk-taking behavior under uncertainty is explored and evaluated. In this model, Tversky and Kahneman's prospect theory provides a theoretical and operational basis for weighing a driver's different alternatives. The model is implemented and tested to assess its properties and those of the resulting traffic stream behavior.
Targeting mtor-Dependent Tumours with Specific Inhibitors: A Model for Personalized Medicine based on Molecular Diagnoses
Authors: Furic L. , Livingstone M. , Dowling R. J. O. , Sonenberg Nahum
Published: February 2009

Cancer cells are characterized by aberrant growth arising from deregulated signalling pathways. The mammalian target of rapamycin (mtor) pathway integrates multiple growth signals coming from both intracellular and extracellular cues. In this short review, we summarize what is known about the efficacy of targeting the mtor pathway to treat cancer patients, and we explain the rationale behind promising new inhibitors that could show more potent tumour growth inhibition than did the first generation of these drugs.
El personal de la biblioteca universitaria y la alfabetización informacional: de la autopercepción a las realidades y retos formativos
Authors: Pinto María , Sales Dora , Martínez-Osorio Pilar
Published: February 2009

El presente trabajo se presenta como un diagnóstico empírico acerca de la percepción que el personal bibliotecario de las Bibliotecas Universitarias en España tiene con respecto a su formación y competencia en Alfabetización Informacional (ALFIN). Tras la recogida de datos a partir de un cuestionario cualitativo que implementamos en el marco de un curso online de formación sobre ALFIN, se analizan los resultados para observar cuál es el estado de la cuestión y, por tanto, cuáles son los retos formativos ante los que cabría comenzar a actuar.
Análisis de la productividad científica y visibilidad de las publicaciones sobre usabilidad (1971-2005)
Authors: Bolaños-Pizarro Máxima , Vidal-Infer Antonio , Navarro-Molina Carolina , Valderrama-Zurián Juan Carlos , González-Alcaide Gregorio , Aleixandre-Benavent Rafael
Published: February 2009

Objetivo: Analizar los artículos sobre usabilidad publicados durante el periodo 1971-2005 desde el punto de vista bibliométrico. Material y Métodos: Para obtener los trabajos se interrogaron las bases de datos del CSIC, Social Science Citation Index, Science Citation Index, PsycInfo, MEDLINE e Inspec mediante estrategias de búsqueda diseñadas ad hoc para cada base de datos. Se calcularon los índices de aporte, aporte específico y solapamiento y los indicadores de evolución de la productividad científica, productividad de las instituciones de trabajo y de las revistas, y distribución de las revistas por área de conocimiento. Resultados: Se ha observado un crecimiento exponencial de los artículos publicados, más acusado en el último quinquenio. Las instituciones más productivas son fundamentalmente universitarias y estadounidenses y las revistas más productivas pertenecen al campo de la informática, ingeniería y psicología. Conclusiones: en la actualidad existe una incógnita sobre la consideración de la usabilidad como ciencia o disciplina científica, ya que no cuenta con un currículo formativo acorde, ni un perfil profesional determinado, ni un área específica de conocimiento en la que se pueda englobar.
Análisis cuantitativo de las noticias de alimentación en la prensa madrileña en 2006
Authors: Fúster Fernando , Ribes Miguel Ángel , Bardón Rocío , Marino Eloy
Published: February 2009

Se han analizado las noticias relacionadas con alimentación y nutrición que aparecen en la prensa escrita (diaria y suplementos semanales) publicadas en la Comunidad de Madrid durante el año 2006 con el fin de conocer cuáles tienen mayor difusión en estos medios y mejorar la orientación de nuestras intervenciones hacia las temáticas consideradas más interesantes o deficitarias. El panorama informativo del año estudiado se ve acaparado, con gran diferencia, por temas relacionados con nutrición y salud, fundamentalmente referidos a obesidad, enfermedades cardiovasculares, anorexia, actividad física y sedentarismo, índice de masa corporal, dieta, etc., frente a otras temáticas como seguridad alimentaria, hábitos alimentarios, alimentos y propiedades y calidad alimentaria.
Interactive Boards and their Function in Education
Authors: Fuvesi Istvan
Published: February 2009

In our accelerating world even education has become market-oriented. Learners have to acquire greater and greater amount of knowledge while the number of contact lessons, especially in higher education, become less and less. That is why giving particular information belonging to a certain topic should be raised â?? one method for this would be visualisation. This means that lectures would be structured in a way that the usual verbal lessons are supplemented by diversed and spectacular visual information. If the informations were followed by pictures, such as diversed diagrams and shown in an interactive way, accompanied by sound effects, the efficacy of teaching would get intensified. The fact that education-supporting new means and circumstances of learning, calls for changes in the methodology of teaching and learning; the educators are required to apply new teaching strategies. Here we would like to present the means and use of Informational and Communicational Technology (in the following: ICT), applied in informatics major. Besides, we also intend to introduce a new framework which plays an important role in forwarding learning material to students. An international lecture course serves as basis for the complex introduction of this framework.
Continuity of aggression from childhood to early adulthood as a predictor of life outcomes: implications for the adolescent‐limited and life‐course‐persistent models
Authors: Huesmann L. Rowell , Dubow Eric F. , Boxer Paul
Published: February 2009

Using data from the Columbia County Longitudinal Study, a 40‐year longitudinal study following an entire county's population of third‐grade students from age 8 to 48, we examine questions about the long‐term consequences of aggressive and antisocial behavior in childhood, adolescence, and young adulthood. We found moderate levels of continuity of aggression from age 8 to 48 both for males and for females. Contrary to what some have proposed, we found that continuity of aggressiveness is owing to not only the high‐aggressive participants staying high but also owing to the low‐aggressive participants staying low. Compared with life‐course‐persistent low aggressives, we found that life‐course‐persistent high aggressives had consistently poorer outcomes across domains of life success, criminal behavior, and psychosocial functioning at age 48 (e.g., arrests, traffic violations, aggression toward spouse and divorces, depression, health, occupational and educational attainment). In contrast, adolescent‐limited and child‐limited aggressives did not differ from life‐course‐persistent low aggressives on the age 48 outcomes. Finally, the outcomes for late‐onset (early adulthood) aggressives were also problematic in some domains though not as problematic as those for life‐course‐persistent aggressives. Aggr. Behav. 35:136–149, 2009. © 2009 Wiley‐Liss, Inc.
Interfacial Strain‐Induced Oxygen Disorder as the Cause of Enhanced Critical Current Density in Superconducting Thin Films
Authors: Wimbush Stuart C. , Li Meicheng , Vickers Mary E. , Maiorov Boris , Feldmann D. Matt , Jia Quanxi , MacManus‐Driscoll Judith L.
Published: February 2009

To understand the origin of the increase in critical current density of rare earth barium cuprate superconductor thin films with decreasing thickness, a series of sub‐300‐nm EuBa2Cu3O7−δ thin films deposited on SrTiO3 substrates are studied by X‐ray diffraction and electrical transport measurements. The out‐of‐plane crystallographic mosaic tilt and the out‐of‐plane microstrain both increase with decreasing film thickness. The calculated density of c‐axis threading dislocations matches the extent of the observed low‐field enhancement in critical current density for fields applied parallel to c. The in‐plane mosaic twist and in‐plane microstrain are both around twice the magnitude of the out‐of‐plane values, and both increase with decreasing film thickness. The results are consistent with the observed stronger field enhancement in critical current density for fields applied parallel to ab. The lattice parameter variation with thickness is not as expected from consideration of the biaxial strain with the substrate, indicative of in‐plane microstrain accommodation by oxygen disorder. Collectively, the results point to an enhancement of critical current by interfacial strain induced oxygen disorder which is greatest closest to the film‐substrate interface. The findings of this study have important implications for other thin functional oxide perovskite films and nanostructures where surface and interfacial strains dominate the properties.
Fabrication of Large‐Scale Single‐Crystalline PrB6 Nanorods and Their Temperature‐Dependent Electron Field Emission
Authors: Zhang Qin Yuan , Xu Jun Qi , Zhao Yan Ming , Ji Xiao Hong , Lau Shu Ping
Published: February 2009

A simple catalysis‐free approach that utilises a gas–solid reaction for the synthesis of large‐scale single‐crystalline PrB6 nanorods using Pr and BCl3 as starting materials is demonstrated. The nanorods exhibit a low turn‐on electric field (2.80 V µ‐b;m−1 at 10 µ‐b;A cm−2), a low threshold electric field (6.99 V µ‐b;m−1 at 1 mA cm−2), and a high current density (1.2 mA cm−2 at 7.35 V µ‐b;m−1) at room temperature (RT). The turn‐on and threshold electric field are found to decrease clearly from 2.80 to 0.95 and 6.99 to 3.55 V µ‐b;m−1, respectively, while the emission current density increases significantly from 1.2 to 13.8 mA cm−2 (at 7.35 V µ‐b;m−1) with an increase in the ambient temperature from RT to 623 K. The field enhancement factor, emission current density, and the dependence of the effective work function with temperature are investigated. The possible mechanism of the temperature‐dependent emission from PrB6 nanorods is discussed.
H2xMnxSn3‐xS6 (x = 0.11–0.25): A Novel Reusable Sorbent for Highly Specific Mercury Capture Under Extreme pH Conditions
Authors: Manos Manolis J. , Petkov Valeri G. , Kanatzidis Mercouri G.
Published: February 2009

The H2xMnxSn3‐xS6 (x = 0.11–0.25) is a new solid acid with a layered hydrogen metal sulfide (LHMS). It derives from K2xMnxSn3–xS6 (x = 0.5–0.95) (KMS‐1) upon treating it with highly acidic solutions. We demonstrate that LHMS‐1 has enormous affinity for the very soft metal ions such as Hg2+ and Ag+ which occurs via a rapid ion exchange process. The tremendous affinity of LHMS‐1 for Hg2+ is reflected in very high distribution coefficient KdHg values (>106 mL g−1). The large affinity and selectivity of LHMS‐1 for Hg2+ persists in a very wide pH range (from less than zero to nine) and even in the presence of highly concentrated HCl and HNO3 acids. LHMS‐1 is significantly more selective for Hg2+ and Ag+ than for the less soft cations Pb2+ and Cd2+. The Hg2+ ions are immobilized in octahedral sites between the sulfide layers of the materials via Hg–S bonds as suggested by pair distribution function (PDF) analysis. LHMS‐1 could decrease trace concentrations of Hg2+ (e.g. <100 ppb) to well below the acceptable limits for the drinking water in less than two min. Hg‐laden LHMS‐1 shows a remarkable hydrothermal stability and resistance in 6 M HCl solutions. LHMS‐1 could be regenerated by treating Hg‐loaded samples with 12 M HCl and re‐used without loss of its initial exchange capacity.
Noble Metal Nanocrystal‐Incorporated Fullerene‐Like Polyoxometalate Based Microspheres
Authors: Nisar Amjad , Xu Xiangxing , Shen Shuling , Hu Shi , Wang Xun
Published: February 2009

Monodisperse fullerene‐like polyoxometalate‐based microspheres are synthesized using a single‐phase approach which is quick, easier to control surfactant to polyoxometalate (POM) molar ratios and result in better control over the size‐distribution range. Noble‐metal nanocrystals are successfully incorporated in the surfactant encapsulated complex multilayered spherical assemblies without any change in their layered morphology. Combining the merits of fullerene‐like POMs and monodisperse noble metal nanocrystals, these monodisperse hybrid spheres show interesting composition‐ and size‐dependent photochemical properties.
Palladium‐Catalysed Telomerisation of Isoprene with Glycerol and Polyethylene Glycol: A Facile Route to New Terpene Derivatives
Authors: Gordillo Alvaro , Pachón Laura Durán , de Jesus Ernesto , Rothenberg Gadi
Published: February 2009

magnified image

We present here the first example of the telomerisation of isoprene with glycerol and polyethylene glycol (PEG‐200), opening a facile route to new terpene structures, based on a combination of renewable and petroleum‐based feedstocks. The reaction is catalysed by a palladium‐carbene complex. Significantly, this system gives >99% of linear monotelomer products. The factors that govern substrate conversion, dimerisation/telomerisation selectivity, and catalyst activity are studied and discussed.
Copper(II)‐Catalyzed Aminooxygenation and Carboamination of N‐Aryl‐2‐allylanilines
Authors: Sherman Eric S. , Chemler Sherry R.
Published: February 2009

magnified image

The scope of the intramolecular copper(II)‐catalyzed carboamination and aminooxygenation reactions of olefins has been extended to include N‐aryl‐2‐allylanilines. These substrates exhibit divergent reactivity under catalytic vs. stoichiometric conditions.
Urinary cysteinyl leukotriene E4 significantly increases during pain in children and adults with sickle cell disease
Authors: Field Joshua J. , Strunk Robert C. , Knight‐Perry Jessica E. , Blinder Morey A. , Townsend R. Reid , DeBaun Michael R.
Published: February 2009

Baseline level of the cysteinyl leukotriene (CysLT), leukotriene E4 (LTE4), is associated with an increased pain rate in children and adults with sickle cell disease (SCD). To provide additional evidence for a role of CysLTs in the pathogenesis of vaso‐occlusion, we tested the hypothesis that LTE4 levels will increase within an individual during painful episodes compared to baseline. In a cohort of 19 children and adults with SCD, median LTE4 levels increased from 82.36 pg/mg creatinine at baseline to 162.81 pg/mg creatinine during a painful episode (P < 0.001). These data further support a contribution of CysLTs to the process of vaso‐occlusion. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.
Rituximab‐associated acute thrombocytopenia: An under‐diagnosed phenomenon
Authors: Ram Ron , Bonstein Lilach , Gafter‐Gvili Anat , Ben‐Bassat Isaac , Shpilberg Ofer , Raanani Pia
Published: February 2009

Acute infusion reactions are the most common documented adverse reactions reported with rituximab, with overt cytokine release syndrome, and hematological adverse events being much rarer. The clinical course of a patient with mantle cell lymphoma, who developed acute thrombocytopenia and leukopenia following rituximab administration, is described and the literature reviewed. Serum complement and the levels of three cytokines—TNF‐α, IL‐6, and IL‐1, were measured 2 days after the infusion of rituximab by using ELISA assay. Drug‐dependent antibodies against platelets were evaluated by two procedures as follows: an immunofluorescence test applying flow cytometry and Monoclonal Antibody Immobilization of Platelet Antigen (MAIPA). Serum levels of TNF‐a were significantly increased compared with normal, whereas those of IL‐6 and IL‐1 were not increased significantly. Flow cytometry assay and the MAIPA assay failed to detect rituximab‐dependent antibodies against platelets. Complement levels were decreased compared with normal. Literature search yielded 10 publications reporting on another 15 patients. The most common type of lymphoma was mantle cell lymphoma, six patients had bone marrow involvement, and 10 patients had splenomegaly. In 10 patients, acute cytopenia was preceded by cytokine release syndrome or infusion‐related symptoms. Usually, thrombocytopenia was not associated with bleeding manifestations. Thrombocytopenia was the most commonly acute cytopenia reported. The postulated pathogenesis is associated with cytokine release syndrome and complement activation. Patients with potential risk factors like splenomegaly and bone marrow involvement, who develop clinical manifestations compatible with cytokine release syndrome, should be closely monitored for rituximab‐associated cytopenia. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.
A socio‐historical hypothesis for the diabetes epidemic in Chinese—Preliminary observations from Hong Kong as a natural experiment
Authors: Schooling C.M. , Lam T.H. , Janus E.D. , Cowling B.J. , Leung G.M.
Published: February 2009

It has been hypothesized that the emerging epidemic of diabetes in economically transitioning or recently transitioned populations is due to mismatch between developmental and mature environments. We took advantage of migration within an ethnically homogenous population to investigate this hypothesis, and the potentially modifying role of postnatal growth conditions, proxied by greater height. We used multivariable logistic regression in a population‐based cross‐sectional study from 1994 to 1996 of 2,341 long‐term Hong Kong residents aged 25–74 years, either born in contemporaneously developed Hong Kong or migrants from economically undeveloped Guangdong. Migrant status was not associated with clinically diagnosed diabetes, odds ratio 1.05 (95% confidence interval 0.69–1.58) in adult migrants compared to Hong Kong‐born natives and 1.22 (0.83–1.80) in preadult migrants, adjusted for age, sex, socio‐economic position, and lifestyle. However, the association of diabetes with migrant status varied with height, suggesting a potentially complex relationship between indicators of prenatal and postnatal nutritional exposures. Compared to tall Hong Kong‐born natives, the odds ratio of diabetes was 2.36 (1.20–4.61) in tall migrants, 1.94 (1.07–3.53) in short Hong Kong‐born natives, but 1.04 (0.48–2.23) in short adult migrants. Additionally adjusting for body mass index and waist‐hip ratio had little effect, apart from attenuating the association between short height and diabetes prevalence in Hong Kong‐born natives. Whether the current epidemic of diabetes is a long‐standing effect of such mismatch or a “first‐generation through effect” generated by rapid economic development causing disproportionate growth remains to be determined. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Afro‐derived Brazilian populations: Male genetic constitution estimated by Y‐chromosomes STRs and AluYAP element polymorphisms
Authors: Ribeiro Guilherme Galvarros Bueno Lobo , De Lima Reginaldo Ramos , Wiezel Cláudia Emília Vieira , Ferreira Luzitano Brandão , Sousa Sandra Mara Bispo , Rocha Dulce Maria Sucena , Canas Maria Do Carmo Tomitão , Nardelli‐Costa Juliana , Klautau‐Guimarães Maria De Nazaré , Simões Aguinaldo Luiz , Oliveira Silviene Fabiana
Published: February 2009

The genetic constitution of Afro‐derived Brazilian populations is barely studied. To improve that knowledge, we investigated the AluYAP element and five Y‐chromosome STRs (DYS19, DYS390, DYS391, DYS392, and DYS393) to estimate ethnic male contribution in the constitution of four Brazilian quilombos remnants: Mocambo, Rio das Rãs, Kalunga, and Riacho de Sacutiaba. Results indicated significant differences among communities, corroborating historical information about the Brazilian settlement. We concluded that besides African contribution, there was a great European participation in the constitution of these four populations and that observed haplotype variability could be explained by gene flow to quilombos remnants and mutational events in microsatellites (STRs). Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Family migration and physical growth in Merida, Yucatan, Mexico
Authors: Azcorra Hugo , Dickinson Federico , Rothenberg Stephen J.
Published: February 2009

Merida city in Yucatan, Mexico, has received rural‐to‐urban migration for decades, with most immigrants settling in the city's southern neighborhoods. Exposure of immigrants to new environmental and sociocultural conditions can generate biological responses, including changes in physical growth pattern at early age. We performed a study to identify and measure the effects of family migration into south Merida on growth in 4‐ to 6‐year‐old children, measuring weight, height, sitting height, and calculated arm muscle and fat areas of 445 children: 228 natives (116 females) and 217 immigrants (118 females) and collecting family social and demographic data. Statistical analysis focused on determining differences in growth, socioeconomic, and biological variables by migratory condition and generating multiple regression models for each growth measurement. No univariate statistical differences (P > 0.05, Student's t‐test) were observed in growth between studied children. Multiple regression analyses showed age, sex, mother's height, birth order, birth weight, family income, zone of residence, diet, and febrile episodes had an effect on growth. Neither the migration variable used above nor any other definition of migrant had a significant effect on growth. The lack of differences in growth between immigrant and native children is probably due to similarity in socioeconomic conditions of their families. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Changes in serum immunity during pregnancy
Authors: Miller Elizabeth M.
Published: February 2009

Pregnancy requires a host of localized immune factors that allow the mother to tolerate the fetus. Changes in the mother's serum immunity during pregnancy are less well‐known. To clarify these changes, 1,351 women from the NHANES 1999–2000 were analyzed with complex survey regression to test the effect of pregnancy on adaptive and innate immune markers. Adjusting for age and BMI, pregnant women had higher C‐reactive protein levels and white blood cell counts and lower measles antibody titer and lymphocyte counts than nonpregnant women. This dual pattern of immunological changes supports the hypothesis that mothers will reduce the ability of the adaptive immune system to respond to infection while increasing the activity of innate immunity during pregnancy, maintaining immune function homeostasis. The function of these homeostatic immune responses is unknown. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Evaluation of antral follicle growth in the macaque ovary during the menstrual cycle and controlled ovarian stimulation by high‐resolution ultrasonography
Authors: Bishop Cecily V. , Sparman Michelle L. , Stanley Jessica E. , Bahar Alistair , Zelinski Mary B. , Stouffer Richard L.
Published: February 2009

To date, ultrasonography of monkey ovaries is rare and typically of low resolution. The objectives of this study were to use state‐of‐the‐art, high‐resolution, transabdominal ultrasonography with real‐time Doppler capabilities to: (1) determine whether one can reliably detect in real time the large dominant follicle, the corpus luteum (CL), and small (<2 mm) antral follicles on the ovaries of rhesus monkeys during the natural menstrual cycle; and (2) predict the follicular response of rhesus ovaries to controlled ovarian stimulation (COS) protocols. Rhesus monkeys were selected for transabdominal ultrasonography using a GE Voluson 730 Expert Doppler System at discrete stages of the menstrual cycle. Subsequently, serial ultrasound scanning was employed to observe growth of antral follicles and the CL. Finally, females were scanned to assess follicular growth during COS. The dominant structure and small antral follicles (<2 mm) were reliably visualized in real time. The follicle destined to ovulate could be identified by size differential by day 3 of the follicular phase. The number of small antral follicles present before onset of COS protocol correlated positively with the number of metaphase II‐stage oocytes collected after treatment. The results of this study demonstrate that the population dynamics of antral follicle pools can be noninvasively evaluated in monkeys during natural and pharmacologic ovarian cycles. Am. J. Primatol. 71:384–392, 2009. © 2009 Wiley‐Liss, Inc.
Hydrid‐Donor‐Stärke von 1,4‐Dihydropyridinen: ein Vergleich mit π‐Nucleophilen und Borhydrid‐Anionen
Authors: Richter Dorothea , Mayr Herbert
Published: February 2009

Was haben Dihydropyridine und Indole gemeinsam? Beide Substanzklassen weisen ähnliche Nucleophilie‐Parameter N auf und sind daher geeignete Substrate für Iminium‐katalysierte Reaktionen α,β‐ungesättigter Aldehyde. Die N‐Parameter von 1,4‐Dihydropyridinen wurden aus den Geschwindigkeiten der Hydridübertragungen auf Benzhydrylium‐Ionen bestimmt (siehe Schema).

magnified image
Asymmetrische Hydroborierung von 1,1‐disubstituierten Alkenen
Authors: Thomas Stephen P. , Aggarwal Varinder K.
Published: February 2009

Ein Durchbruch bei der asymmetrischen Hydroborierung der als „schwierig“ geltenden 1,1‐disubstituierten Alkene gelingt mit einer neuen Klasse hoch effizienter Hydroborierungsreagentien (siehe Schema). Die Boranzwischenstufen lassen sich zu Alkoholen oxidieren oder in Suzuki‐Miyaura‐Kreuzkupplungen einsetzen.

magnified image
Radical Polymerization of the Silene (Me3Si)2SiCR2 by Hydrogen Transfer from a Trimethylsilyl Group
Authors: Bravo‐Zhivotovskii Dmitry , Melamed Semyon , Molev Victoria , Sigal Nadejda , Tumanskii Boris , Botoshansky Mark , Molev Gregory , Apeloig Yitzhak
Published: February 2009

Die Polymerisation des Titelsilens (Me3Si)2SiAd ergibt ein Polycarbosilan mit einem Rückgrat aus ungewöhnlichen Si‐Si‐C‐Wiederholungseinheiten und nicht, wie analog zur radikalischen Olefinpolymerisation erwartet, aus Si‐C‐ oder Si‐Si‐C‐C‐Einheiten. Die Struktur des Polymers und der Polymerisationsmechanismus (siehe Schema) wurden mithilfe von GPC, EPR‐ und NMR‐Spektroskopie sowie durch Abfangexperimente untersucht.

magnified image
Innentitelbild: Self‐Template‐Directed Formation of Coordination‐Polymer Hexagonal Tubes and Rings, and their Calcination to ZnO Rings (Angew. Chem. 8/2009)
Authors: Jung Soyoung , Cho Won , Lee Hee Jung , Oh Moonhyun
Published: February 2009

Hexagonale Röhren und Ringe mit ungewöhnlichen Formen wurden durch einen einzigartigen Autotemplatmechanismus erzeugt. Wie M. Oh und Mitarbeiter in der Zuschrift auf S. 1487 ff. beschreiben, wirken anfänglich gebildete Koordinationspolymerpartikel (CPPs) als Template für die wachsenden hexagonalen Röhren und Ringe. Einfaches Kalzinieren der CPPs führt zur spontanen Bildung von ZnO‐Partikeln, die die speziellen Formen der CPPs beibehalten.

magnified image
Development of Tau Aggregation Inhibitors for Alzheimer's Disease
Authors: Bulic Bruno , Pickhardt Marcus , Schmidt Boris , Mandelkow Eva‐Maria , Waldmann Herbert , Mandelkow Eckhard
Published: February 2009

Small molecules against Alzheimer's: The pathological aggregation of the tau protein is a major hallmark of neurodegenerative diseases such as Alzheimer's disease. The inhibition or reversal of tau aggregation is a potential therapeutic strategy that is currently undergoing clinical trials. The image shows pathological fibers assembled from tau protein, which are the main components of the neurofibrillary tangles of Alzheimer's disease.

magnified image

A variety of human diseases are suspected to be directly linked to protein misfolding. Highly organized protein aggregates, called amyloid fibrils, and aggregation intermediates are observed; these are considered to be mediators of cellular toxicity and thus attract a great deal of attention from investigators. Neurodegenerative pathologies such as Alzheimer's disease account for a major part of these protein misfolding diseases. The last decade has witnessed a renaissance of interest in inhibitors of tau aggregation as potential disease‐modifying drugs for Alzheimer's disease and other “tauopathies”. The recent report of a phase II clinical trial with the tau aggregation inhibitor MTC could hold promise for the validation of the concept. This Review summarizes the available data concerning small‐molecule inhibitors of tau aggregation from a medicinal chemistry point of view.
Asymmetric Hydroboration of 1,1‐Disubstituted Alkenes
Authors: Thomas Stephen P. , Aggarwal Varinder K.
Published: February 2009

A breakthrough in the asymmetric hydroboration of notoriously difficult 1,1‐disubstituted alkenes using a new family of highly effective hydroboration reagents is described (see scheme). The intermediate boranes can be oxidized to alcohols or used in Suzuki–Miyaura cross‐coupling reactions.

magnified image
Synthesis and Characterization of [Ar′GaC(Ph)CH]2 and K2[Ar′GaC(Ph)CH]2⋅OEt2: From Digallene to Digallacyclohexadiene to Digallatabenzene
Authors: Zhu Zhongliang , Wang Xinping , Olmstead Marilyn M. , Power Philip P.
Published: February 2009

On a plane: Addition of PhCCH to Ar′GaGaAr′ (Ar′=2,6‐(2,6‐iPr2C6H3)2C6H3) yielded the 1,4‐digallacyclohexadiene [{Ar′GaC(Ph)CH}2] (1), which afforded the 1,4‐digallatabenzene dianion [Ar′GaC(Ph)CH]22− (2) upon reduction with potassium (see scheme; C gray, Ga green, K blue). Structural parameters, DFT calculations, and 1H NMR spectroscopy support aromatic character of 2.

magnified image
Cover Picture: A Spin‐Crossover Cluster of Iron(II) Exhibiting a Mixed‐Spin Structure and Synergy between Spin Transition and Magnetic Interaction (Angew. Chem. Int. Ed. 8/2009)
Authors: Wu Da‐Yu , Sato Osamu , Einaga Yasuaki , Duan Chun‐Ying
Published: February 2009

A spin‐crossover cluster with the {FeII4O4} core structure is presented by D. Y. Wu, O. Sato et al. in their Communication on page 1475 ff. The cluster is synthesized by self‐assembly and shows an abrupt spin transition, giving two high‐spin and two low‐spin states. It exhibits complete light‐induced excited spin‐state trapping effects. Importantly, synergy effects between the magnetic interaction and spin transition operate in the cluster.

magnified image
Inside Cover: Self‐Template‐Directed Formation of Coordination‐Polymer Hexagonal Tubes and Rings, and their Calcination to ZnO Rings (Angew. Chem. Int. Ed. 8/2009)
Authors: Jung Soyoung , Cho Won , Lee Hee Jung , Oh Moonhyun
Published: February 2009

Hexagonal tubes and rings with unusual shapes were generated through a unique self‐template‐directed growth mechanism. As described by M. Oh and co‐workers in the Communication on page 1459 ff., initially formed solid coordination polymer particles (CPPs) act as templates for the growth of the final hexagonal tubes and rings. Simple calcination of these unusually shaped CPPs results in the spontaneous formation of ZnO particles while the unique shape is maintained.

magnified image
The Case Anatomical Knowledge Index (CAKI): A novel method used to assess anatomy content in clinical cases
Authors: Banda Sekelani S.
Published: February 2009

There are concerns in the literature that the use of case‐based teaching of anatomy could be compromising the depth and scope of anatomy learned by students in a problem‐based learning curriculum. Poor selection of clinical cases that are used as vehicles for teaching/learning anatomy may be the root problem because some clinical cases do not provide enough opportunities to learn anatomy and are, therefore, inappropriate for case‐based teaching. Although anatomy educators are expected to respond to the identified deficiencies of case‐based anatomy teaching, making sure that students acquire sufficient anatomical knowledge to practice safely and successfully, there are no tools available that can help improve the selection of clinical cases for case‐based teaching. The author proposes a composite index, which incorporates considerations of anatomical knowledge for evaluating clinical cases/conditions for suitability in case‐based anatomy teaching. The development of the case anatomical knowledge index (CAKI) using a modified Guttman procedure is described. The scalability of the index was measured using the coefficient of reproducibility. A total of 47 clinicians participated in the validation activities that measured interrater and intraclass reliability. The CAKI was able to consistently discriminate between clinical cases/conditions with higher demand for anatomical knowledge than those with lower demand for anatomical knowledge. A review of the literature suggests that such an index has not been previously reported. Given the concerns about the depth and scope of anatomy learning in case‐based teaching, these findings have international relevance. Anat Sci Ed 2:9–18, 2009. © 2009 American Association of Anatomists.
Passage detection using text classification
Authors: Mengle Saket , Goharian Nazli
Published: February 2009

Passages can be hidden within a text to circumvent their disallowed transfer. Such release of compartmentalized information is of concern to all corporate and governmental organizations. Passage retrieval is well studied; we posit, however, that passage detection is not. Passage retrieval is the determination of the degree of relevance of blocks of text, namely passages, comprising a document. Rather than determining the relevance of a document in its entirety, passage retrieval determines the relevance of the individual passages. As such, modified traditional information‐retrieval techniques compare terms found in user queries with the individual passages to determine a similarity score for passages of interest. In passage detection, passages are classified into predetermined categories. More often than not, passage detection techniques are deployed to detect hidden paragraphs in documents. That is, to hide information, documents are injected with hidden text into passages. Rather than matching query terms against passages to determine their relevance, using text‐mining techniques, the passages are classified. Those documents with hidden passages are defined as infected. Thus, simply stated, passage retrieval is the search for passages relevant to a user query, while passage detection is the classification of passages. That is, in passage detection, passages are labeled with one or more categories from a set of predetermined categories. We present a keyword‐based dynamic passage approach (KDP) and demonstrate that KDP outperforms statistically significantly (99% confidence) the other document‐splitting approaches by 12% to 18% in the passage detection and passage category‐prediction tasks. Furthermore, we evaluate the effects of the feature selection, passage length, ambiguous passages, and finally training‐data category distribution on passage‐detection accuracy.
Describing and predicting information‐seeking behavior on the Web
Authors: Kim Jeonghyun
Published: February 2009

This study focuses on the task as a fundamental factor in the context of information seeking. The purpose of the study is to characterize kinds of tasks and to examine how different kinds of task give rise to different kinds of information‐seeking behavior on the Web. For this, a model for information‐seeking behavior was used employing dimensions of information‐seeking strategies (ISS), which are based on several behavioral dimensions. The analysis of strategies was based on data collected through an experiment designed to observe users' behaviors. Three tasks were assigned to 30 graduate students and data were collected using questionnaires, search logs, and interviews. The qualitative and quantitative analysis of the data identified 14 distinct information‐seeking strategies. The analysis showed significant differences in the frequencies and patterns of ISS employed between three tasks. The results of the study are intended to facilitate the development of task‐based information‐seeking models and to further suggest Web information system designs that support the user's diverse tasks.
Morphofunctional study of 12‐O‐tetradecanoyl‐13‐phorbol acetate (TPA)‐induced differentiation of U937 cells under exposure to a 6 mT static magnetic field
Authors: Dini Luciana , Dwikat Majdi , Panzarini Elisa , Vergallo Cristian , Tenuzzo Bernadetta
Published: February 2009

This study deals with the morphofunctional influence of 72 h exposure to a 6 mT static magnetic field (SMF) during differentiation induced by 50 ng/ml 12‐O‐tetradecanoyl‐13‐phorbol acetate (TPA) in human leukaemia U937 cells. The cell morphology of U937 cells was investigated by optic and electron microscopy. Specific antibodies and/or molecules were used to label CD11c, CD14, phosphatidylserine, F‐actin and to investigate the distribution and activity of lysosomes, mitochondria and SER. [Ca2+]i was evaluated with a spectrophotometer. The degree of differentiation in SMF‐exposed cells was lower than that of non‐exposed cells, the difference being exposure time‐dependent. SMF‐exposed cells showed cell shape and F‐actin modification, inhibition of cell attachment, appearance of membrane roughness and large blebs and impaired expression of specific macrophagic markers on the cell surface. The intracellular localization of SER and lysosomes was only partially affected by exposure. A significant localization of mitochondria with an intact membrane potential at the cell periphery in non‐exposed, TPA‐stimulated cells was observed; conversely, in the presence of SMF, mitochondria were mainly localised near the nucleus. In no case did SMF exposure affect cell viability. The sharp intracellular increase of [Ca2+]i could be one of the causes of the above‐described changes. Bioelectromagnetics 30:352–364, 2009. © 2009 Wiley‐Liss, Inc.
AIFIT – Anwenderorientierte Identifikation für Ingenieurtragwerke
Authors: Hoffmann Simon , Wendner Roman , Strauss Alfred , Steinhauser Wolfgang
Published: February 2009

Anhand von bereits in einem ersten Beitrag beschriebenen Laborversuchen wurden verschiedene Methoden zur Systemidentifikation in ihrer Leistungsfähigkeit hinsichtlich der Bestimmung von Steifigkeitsverteilungen untersucht. Um darüber hinaus dem Anspruch des Projekts AIFIT anwenderorientierte Identifikationsverfahren bereit zu stellen, gerecht zu werden, gilt es nun, den realistischen Einsatz dieser Verfahren näher zu untersuchen. Zu diesem Zweck wurden die im Labor gewonnen Erfahrungen unter Berücksichtigung einer möglichst zweckmäßigen Anwendung in einem Feldversuch umgesetzt. Hierzu wurde ein repräsentatives Bauwerk untersucht und dessen dynamisches und quasi statisches Verhalten aufgenommen. Die mittels dieser Informationen gewonnen Erkenntnisse über die Steifigkeitsverteilung im Bauwerk sollen letztendlich eine Hilfestellung in der Inspektion und Erhaltungsplanung von Brückenbauwerken bieten.
Feldversuche mit dem Brückenklappverfahren
Authors: Blail Susanne , Kollegger Johann
Published: February 2009

Aufbauend auf dem Bogenklappverfahren wird ein Herstellungsverfahren für Brückenträger vorgeschlagen, bei dem auf die Errichtung eines Lehrgerüsts verzichtet werden kann und während der Herstellung der Brückenträger keine Biegebeanspruchungen in den Brückenträgern auftreten. Das bekannte Verfahren der Kletterschalung, das ohnehin zur Herstellung der Betonpfeiler verwendet wird, kann beim Brückenklappverfahren auch zur Herstellung der Brückenträger eingesetzt werden. Dadurch ergeben sich wirtschaftliche Vorteile gegenüber dem Freivorbau. Die Stützstäbe bzw. Abspannungen reduzieren die Spannweiten der Brückenträger und ermöglichen beträchtliche Masseneinsparungen. Das Brückenklappverfahren wird besonders vorteilhaft bei Brücken mit hohen Pfeilern und bei Spannweiten zwischen 50 m und 250 m einzusetzen sein.
Faser‐ und textilbasierte Lichtleitung in Betonbauteilen – Lichtleitender Beton
Authors: Roye Andreas , Barlé Marijan , Gries Thomas , Janetzko Steffen
Published: February 2009

Lichtleitender Beton ist ein Material, bei dem lichtleitende Fasern in Beton eingearbeitet werden, so dass Betonelemente aus diesem Material transluzent werden. Dieser Artikel beschreibt Grundstoffe und Herstellverfahren des Materials Lichtbeton. Dabei wird ein Schwerpunkt auf die notwendigen lichtleitenden Faserwerkstoffe gelegt. Zwei unterschiedliche Grundprinzipien zur Produktion von Betonelementen mit lichtleitenden Fasern werden vorgestellt.
Zemente mit mehreren Hauptbestandteilen im Betonbau
Authors: Müller Christoph
Published: February 2009

Im Hinblick auf die Verminderung der klimarelevanten CO2‐Emissionen in der Zementindustrie kommt der Herstellung von Zementen mit mehreren Hauptbestandteilen eine besondere Bedeutung zu. Ein Grund dafür liegt – verglichen mit “traditionellen” CEM IZementen (Portlandzementen) – im energieeffizienteren und ökologischeren Herstellungsverfahren. Aber auch die Dauerhaftigkeit und die Leistungsfähigkeit beim Einsatz in Betonbauwerken sorgen dafür, dass Portlandkompositzemente (CEM II) und Hochofenzemente (CEM III) mittlerweile auch in Deutschland einen Marktanteil von rd. 65% erreichen. Europaweit werden schon seit einigen Jahren nur noch annähernd 30% Portlandzement eingesetzt – bei stetig sinkender Tendenz. Nachfolgend werden die anwendungstechnischen Eigenschaften, die Anwendungsmöglichkeiten sowie die ökologischen Vorteile der bisher in Deutschland eingesetzten Zemente mit mehreren Hauptbestandteilen dargestellt und anhand von zwei Praxisbeispielen verdeutlicht. Mit Beispielen für die Leistungsfähigkeit neuer Zemente im Beton erfolgt ein Ausblick in mögliche weitere Entwicklungen.