bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Magma Dynamics with a Mixed Fourier Collocation — Discontinuous Galerkin Method
Authors: Schiemenz Alan R. , Hesse Marc A. , Hesthaven Jan S. 
Published: April 2011

AbstractA high-order discretization consisting of a tensor product of the Fourier collocation and discontinuous Galerkin methods is presented for numerical modeling of magma dynamics. The physical model is an advection-reaction type system consisting of two hyperbolic equations and one elliptic equation. The high-order solution basis allows for accurate and efficient representation of compaction-dissolution waves that are predicted from linear theory. The discontinuous Galerkin method provides a robust and efficient solution to the eigenvalue problem formed by linear stability analysis of the physical system. New insights into the processes of melt generation and segregation, such as melt channel bifurcation, are revealed from two-dimensional time-dependent simulations.
Semiclassical Lattice Boltzmann Simulations of Rarefied Circular Pipe Flows
Authors: Yang Jaw-Yen , Hung Li-Hsin , Kuo Yao-Tien 
Published: April 2011

AbstractComputations of microscopic circular pipe flow in a rarefied quantum gas are presented using a semiclassical axisymmetric lattice Boltzmann method. The method is first derived by directly projecting the Uehling-Uhlenbeck Boltzmann-BGK equations in two-dimensional rectangular coordinates onto the tensor Hermite polynomials using moment expansion method and then the forcing strategy of Halliday et al. [Phys. Rev. E., 64 (2001), 011208] is adopted by adding forcing terms into the resulting microdynamic evolution equation. The determination of the forcing terms is dictated by yielding the emergent macroscopic equations toward a particular target form. The correct macroscopic equations of the incompressible axisymmetric viscous flows are recovered through the Chapman-Enskog expansion. The velocity profiles and the mass flow rates of pipe flows with several Knudsen numbers covering different flow regimes are presented. It is found the Knudsen minimum can be captured in all three statistics studied. The results also indicate distinct characteristics of the effects of quantum statistics.
Finite Volume Evolution Galerkin Methods for the Shallow Water Equations with Dry Beds
Authors: Bollermann Andreas , Noelle Sebastian , Lukáčová-Medvid’ová Maria 
Published: April 2011

AbstractWe present a new Finite Volume Evolution Galerkin (FVEG) scheme for the solution of the shallow water equations (SWE) with the bottom topography as a source term. Our new scheme will be based on the FVEG methods presented in (Noelle and Kraft, J. Comp. Phys., 221 (2007)), but adds the possibility to handle dry boundaries. The most important aspect is to preserve the positivity of the water height. We present a general approach to ensure this for arbitrary finite volume schemes. The main idea is to limit the outgoing fluxes of a cell whenever they would create negative water height. Physically, this corresponds to the absence of fluxes in the presence of vacuum. Wellbalancing is then re-established by splitting gravitational and gravity driven parts of the flux. Moreover, a new entropy fix is introduced that improves the reproduction of sonic rarefaction waves.
Biomaterials that Regulate Growth Factor Activity via Bioinspired Interactions
Authors: Hudalla Gregory A. , Murphy William L. 
Published: April 2011

AbstractGrowth factor activity is localized within the natural extracellular matrix (ECM) by specific noncovalent interactions with core ECM biomolecules, such as proteins and proteoglycans. Recently, these interactions inspired the development of synthetic biomaterials that can noncovalently regulate growth factor activity for tissue‐engineering applications. For example, biomaterials covalently or noncovalently modified with heparin glycosaminoglycans can augment growth factor‐release strategies. In addition, recent studies demonstrate that biomaterials modified with heparin‐binding peptides can sequester cell‐secreted heparin proteoglycans and, in turn, sequester growth factors and regulate stem cell behavior. Another set of studies shows that modular versions of growth factor molecules can be designed to interact with specific components of natural and synthetic ECMs, including collagen and hydroxyapatite. In addition, layer‐by‐layer assemblies of GAGs and other natural polyelectrolytes retain growth factors at a cell/material interface via specific noncovalent interactions. This Feature Article provides a detailed overview of the various bioinspired strategies that are used to noncovalently localize growth factor activity within biomaterials, and will highlight in vivo examples of the efficacy of these materials to promote tissue regeneration.
Circadian activity rhythms and risk of incident dementia and mild cognitive impairment in older women
Authors: Tranah Gregory J. , Blackwell Terri , Stone Katie L. , Ancoli‐Israel Sonia , Paudel Misti L. , Ensrud Kristine E. , Cauley Jane A. , Redline Susan , Hillier Teresa A. , Cummings Steven R. , Yaffe Kristine ,   for the SOF Research Group
Published: April 2011

AbstractObjective:Previous cross‐sectional studies have observed alterations in activity rhythms in dementia patients but the direction of causation is unclear. We determined whether circadian activity rhythms measured in community‐dwelling older women are prospectively associated with incident dementia or mild cognitive impairment (MCI).Methods:Activity rhythm data were collected from 1,282 healthy community‐dwelling women from the Study of Osteoporotic Fractures (SOF) cohort (mean age 83 years) with wrist actigraphy for a minimum of three 24‐hour periods. Each participant completed a neuropsychological test battery and had clinical cognitive status (dementia, MCI, normal) adjudicated by an expert panel approximately 5 years later. All analyses were adjusted for demographics, body mass index (BMI), functional status, depression, medications, alcohol, caffeine, smoking, health status, and comorbidities.Results:After 4.9 years of follow‐up, 195 (15%) women had developed dementia and 302 (24%) had developed MCI. Older women with decreased activity rhythms had a higher likelihood of developing dementia or MCI when comparing those in the lowest quartiles of amplitude (odds ratio [OR] = 1.57; 95% CI, 1.09–2.25) or rhythm robustness (OR = 1.57; 95% CI, 1.10–2.26) to women in the highest quartiles. An increased risk of dementia or MCI (OR = 1.83; 95% CI, 1.29–2.61) was found for women whose timing of peak activity occurred later in the day (after 3:51 PM) when compared to those with average timing (1:34 PM–3:51 PM).Interpretation:Older, healthy women with decreased circadian activity rhythm amplitude and robustness, and delayed rhythms have increased odds of developing dementia and MCI. If confirmed, future studies should examine whether interventions (physical activity, bright light exposure) that influence activity rhythms will reduce the risk of cognitive deterioration in the elderly. ANN NEUROL 2011
Von der Fläche ins Volumen – Materialkonzepte für optisch‐holographische Datenspeicher der Zukunft
Authors: Bruder Friedrich‐Karl , Hagen Rainer , Rölle Thomas , Weiser Marc‐Stephan , Fäcke Thomas 
Published: April 2011

AbstractDie optische Datenspeicherung hat seit Ihrer Markteinführung 1982 das tägliche Leben geprägt. Compact Disk (CD), Digital Versatile Disk (DVD) und Blu‐ray Disk (BD) sind universelle Datenträgerformate mit den Vorteilen des kontaktfreien und damit abnutzungslosen Lesens und Schreibens der digitalen Daten. Sie ermöglichen einen schnellen Datenzugriff, hohe Transferraten und eine stromfreie Datenspeicherung bei sehr günstigen gesamten Archivierungskosten. Der stete Wunsch nach der Erhöhung der Datenspeicherkapazitäten und ‐transferraten treibt die Entwicklung an. Für optische Datenspeicher ist die Nutzung holographischer Prinzipien ein eleganter Weg, diese Parameter weiter zu erhöhen, da hier im Inneren (also im Volumen) des Speichermaterials Daten abgelegt werden und zudem optisch parallel verarbeitet werden können. Dieser Aufsatz beschreibt die grundlegenden Materialanforderungen für holographische Speicher und vergleicht generelle Materialkonzepte. Ein Überblick über aktuelle Demonstrationen von Lese‐Schreib‐Geräten zeigt auf, wie weit die holographische Datenspeicherung schon entwickelt wurde.
Anatomical Boundary of the Tympanic Membrane Pars Flaccida of the Meriones unguiculatus (Mongolian Gerbil)
Authors: Von Unge Magnus , Buytaert Jan A.N. , Dirckx Joris J.J. 
Published: April 2011

AbstractThe pars flaccida of the Meriones unguiculatus (Mongolian gerbil) was in previous studies shown to bulge almost spherically when pressurized, a behavior suggesting that it is suspended by a fixed circular boundary. The question arises whether this “functional” boundary is based on an underlying circular anatomical boundary, an important issue for modeling the middle‐ear mechanics. In this article, the boundaries of the Mongolian gerbil pars flaccida were visualized in situ with otomicroscopy and in slides with light microscopy and by micro‐CT radiology. For the major part of its circumference, the pars flaccida was found to be suspended by rigid bone, that is, the tympanic legs. The remaining boundary is made up of the terminal portion of the handle of the malleus and the soft tissue of the terminal arches. The attachment to these structures is simple and uncomplicated, and the geometry is regular and symmetric: deviating by only 3.5% from a perfect circular shape. The findings justify the use of a fixed circular boundary as a good approximation for the modeling of pars flaccida deformation in the Mongolian gerbil. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
MAOA, DBH, and SLC6A4 variants in CHARGE: a case–control study of autism spectrum disorders
Authors: Tassone Flora , Qi Lihong , Zhang Wenting , Hansen Robin L. , Pessah Isaac N. , Hertz‐Picciotto Irva 
Published: April 2011

AbstractGenetic factors are established to contribute to the development of autism. We examined three loci, serotonin transporter (SLC6A4), dopamine β‐hydroxylase (DBH), and the variable number of tandem repeat promoter of the monoamine oxidase A (MAOA) for association with autism in participants from the Childhood Autism Risks from Genetics and the Environment (CHARGE ) Study, the first large‐scale population‐based case–control investigation of both environmental and genetic contributions to autism risk. Among male children enrolled in the CHARGE study we tested associations between each of the three polymorphisms and autism (AU) (n = 119), or a combined group of autism and other autism spectrum disorders (AU+ASD, which includes an additional n = 53) as compared with typically developing controls (TD, n = 137). The case–control association analysis showed neither SLC6A4 nor DBH to be statistically significantly associated with AU or ASD. However, the male children carrying 4 tandem repeats in the promoter region of the MAOA gene showed a two‐fold higher risk of AU (or AU+ASD) than those carrying allele 3, adjusted for confounders (OR = 2.02, 95% CI = 1.12, 3.65, P = 0.02 for AU vs. TD, and OR = 2.05, 95% CI = 1.19, 3.53, P = 0.01 for ASD vs. TD). In addition, children of mothers homozygous for the 4 tandem repeat allele showed at least a three‐fold higher risk of AU (or AU+ASD) than those with mothers homozygous for allele 3 (OR = 3.07, 95% CI = 1.19, 7.91, P = 0.02 for AU vs. TD, and OR = 3.26, 95% CI = 1.35, 7.89, P = 0.009 for AU+ASD vs. TD). These results suggest a potential role of the functional MAOA promoter alleles in the male child, the mother, or both in ASD. Autism Res 2011,4:250–261. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Adaptation of the “Dynamic Method” for measuring the specific respiration rate in oxygen transfer systems through diffusion membrane
Authors: Pamboukian Marilena Martins , Pereira Carlos Augusto , Augusto Elisabeth de Fatima Pires , Tonso Aldo 
Published: April 2011

AbstractMonitoring the specific respiration rate
(QO2) is a valuable tool to evaluate cell growth and
physiology. However, for low QO2 values the accuracy may depend on
the measurement methodology, as it is the case in animal cell culture. The widely used “Dynamic Method” imposes serious difficulties concerning oxygen transfer cancellation, especially through membrane oxygenation. This paper presents an improved procedure to this method, through an automated control of the gas inlet composition that can minimize the residual oxygen transfer driving force during the QO2 measurement phase. The improved technique was applied to animal cell cultivation, particularly three recombinant S2 (Drosophila melanogaster) insect cell lines grown in a membrane aeration bioreactor. The average measurements of the proposed method reached 98% of stationary liquid phase balance method, taken as a reference, compared to 21% when the traditional method was used. Furthermore, this methodology does not require knowledge of the volumetric transfer coefficient kLa, which may vary during growth.
Prediction of the aggregation propensity of proteins from the primary sequence: Aggregation properties of proteomes
Authors: Castillo Virginia , Graña‐Montes Ricardo , Sabate Raimon , Ventura Salvador 
Published: April 2011

AbstractIn the cell, protein folding into stable globular conformations is in competition with aggregation into non‐functional and usually toxic structures, since the biophysical properties that promote folding also tend to favor intermolecular contacts, leading to the formation of β‐sheet‐enriched insoluble assemblies. The formation of protein deposits is linked to at least 20 different human disorders, ranging from dementia to diabetes. Furthermore, protein deposition inside cells represents a major obstacle for the biotechnological production of polypeptides. Importantly, the aggregation behavior of polypeptides appears to be strongly influenced by the intrinsic properties encoded in their sequences and specifically by the presence of selective short regions with high aggregation propensity. This allows computational methods to be used to analyze the aggregation properties of proteins without the previous requirement for structural information. Applications range from the identification of individual amyloidogenic regions in disease‐linked polypeptides to the analysis of the aggregation properties of complete proteomes. Herein, we review these theoretical approaches and illustrate how they have become important and useful tools in understanding the molecular mechanisms underlying protein aggregation.
Molecular Structures of THF‐Solvated Alkali‐Metal 2,2,6,6‐Tetramethylpiperidides Finally Revealed: X‐ray Crystallographic, DFT, and NMR (including DOSY) Spectroscopic Studies
Authors: Armstrong David R. , García‐Álvarez Pablo , Kennedy Alan R. , Mulvey Robert E. , Robertson Stuart D. 
Published: April 2011

AbstractThe often studied THF solvates of the utility alkali‐metal amides lithium and sodium 2,2,6,6‐tetramethylpiperidide are shown to exist in the solid state as asymmetric cyclic dimers containing a central M2N2 ring and one molecule of donor per metal to give a distorted trigonal planar metal coordination. DFT studies support these structures and confirm the asymmetry in the ring. In C6D12 solution, the lithium amide displays a concentration‐dependent equilibrium between a solvated and unsolvated species which have been shown by diffusion‐ordered NMR spectroscopy (DOSY) to be a dimer and larger oligomer, respectively. A third species, a solvated monomer, is also present in very low concentration, as proven by spiking the NMR sample with THF. In contrast, the sodium amide displays a far simpler C6D12 solution chemistry, consistent with the solid‐state dimeric arrangement but with labile THF ligands.
Sizing of Safety Valves for Multi‐Purpose Plants according to ISO 4126‐10
Authors: Schmidt Jürgen 
Published: April 2011

AbstractMehrzweckanlagen werden oft mit Sicherheitsventilen oder Berstscheiben abgesichert. Bei Produktwechseln muss regelmäßig überprüft werden, ob die Sicherheitseinrichtung für neue Produkte ausreichend groß bemessen ist. Die Auslegung kann jedoch sehr aufwendig sein. Deshalb werden energiespezifische Entlastungsflächen für ca. 60 typische Lösungsmittel bestimmt. Bei der Berechnung mit der HNE‐DS‐Methode, wie in ISO 4126‐10 empfohlen, wurde die Entlastung von Dampf/Flüssigkeits‐Gemischen berücksichtigt. Die Ergebnisse erlauben eine schnelle Bestimmung der erforderlichen Entlastungsfläche, wenn der Energieeintrag in den Reaktor bekannt ist. Es ergeben sich signifikant kleinere Entlastungsflächen als nach dem amerikanischem Regelwerk API 520.
Refractive index dispersion of spinel Zn2TiO4 single crystal
Authors: Li Liang , Fan Ya , Wang Dejun , Feng Guanlin , Xu Dapeng 
Published: April 2011

AbstractThe transmittance and absorption spectra of a high‐quality Zn2TiO4 single crystal have been measured along the a‐axes at room‐temperature in the range of 200‐1000 nm. The wavelength dependent refractive index, extinction coefficient, real and imaginary parts of the complex dielectric constant of the Zn2TiO4 crystal have been derived from the measured T and α spectra. By fitting the refractive index spectrum, the Sellmeier dispersion equation of the Zn2TiO4 crystal has been obtained. The validity of Cauchy‐Sellmeier equation has been evaluated in the energy range of 2.90–3.20 eV representing the Urbach tail. Applying the single‐effective oscillator model, the dispersion energy Ed and the oscillator energy E0 have been determined as 18.76 and 5.05 eV, respectively. The obtained dispersion energy Ed takes on ionic crystal value. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cellometer Vision as an alternative to flow cytometry for cell cycle analysis, mitochondrial potential, and immunophenotyping
Authors: Chan Leo L. , Zhong Xuemei , Qiu Jean , Li Peter Y. , Lin Bo 
Published: April 2011

AbstractCell phenotyping and cell cycle analysis are two commonly used assays in both clinical diagnosis and biomedical research. Cell phenotyping by identifying different biomarkers is essential for the diagnosis of hematologic malignancy, sub‐classifying diseases, monitoring response to treatment, predicting prognosis, detecting rare cell populations and residual malignant cells. Cell cycle analysis distinguishes cells in different phases of cell cycle and is often used to determine the cellular response to drugs and biological stimulations. These assays have been traditionally carried out by sensitive fluorescence detection methods such as flow cytometry and laser scanning cytometry for fluorescence‐based cell population analysis. However, these instruments remain relatively expensive, large in size, and require a considerable amount of maintenance, which may not be feasible for smaller research groups that do not have access to these equipments or field clinics that require quick diagnostic results on site. Recently, a small portable imaging cytometry system (Cellometer Vision) has been developed by Nexcelom Bioscience LLC (Lawrence, MA) for automated cell concentration and viability measurement using bright‐field and fluorescent imaging methods. Here we report new applications of the Cellometer imaging cytometry for fluorescence‐based cell population analysis and compared them with conventional flow cytometry. Cell population analysis assays such as immunophenotyping, cell cycle, and mitochondrial membrane potential detection methods have not yet been reported for the Cellometer Vision system. Using this imaging cytometry method for fluorescence‐based assays that are typically done by flow cytometry offers a quick, simple, and inexpensive alternative method for biomedical research, which may be beneficial for smaller research laboratories and clinics. © 2011 International Society for Advancement of Cytometry
Uncoupling of retinoic acid signaling from tailbud development before termination of body axis extension
Authors: Cunningham Thomas J. , Zhao Xianling , Duester Gregg 
Published: April 2011

AbstractDuring the early stages of body axis extension, retinoic acid (RA) synthesized in somites by Raldh2 represses caudal fibroblast growth factor (FGF) signaling to limit the tailbud progenitor zone. Excessive RA down‐regulates Fgf8 and triggers premature termination of body axis extension, suggesting that endogenous RA may function in normal termination of body axis extension. Here, we demonstrate that Raldh2−/− mouse embryos undergo normal down‐regulation of tailbud Fgf8 expression and termination of body axis extension in the absence of RA. Interestingly, Raldh2 expression in wild‐type tail somites and tailbud from E10.5 onwards does not result in RA activity monitored by retinoic acid response element (RARE)‐lacZ. Treatment of wild‐type tailbuds with physiological levels of RA or retinaldehyde induces RARE‐lacZ activity, validating the sensitivity of RARE‐lacZ and demonstrating that deficient RA synthesis in wild‐type tail somites and tailbud is due to a lack of retinaldehyde synthesis. These studies demonstrate an early uncoupling of RA signaling from mouse tailbud development and show that termination of body axis extension occurs in the absence of RA signaling. genesis 49:776–783, 2011. © 2011 Wiley‐Liss, Inc.
An inducible transgenic Cre mouse line for the study of hippocampal development and adult neurogenesis
Authors: Li Yiping , Tian Chuanxi , Yang Ying , Yan Yan , Ni Yang , Wei Yiquan , Pleasure Samuel J. , Zhao Chunjie 
Published: April 2011

AbstractThe hippocampus is crucial for higher brain functions, such as learning, memory, and emotion. Many diseases like epilepsy and Down's syndrome are associated with abnormalities in early hippocampal development. In addition, adult dentate neurogenesis is thought to be defective in several classes of psychiatric disorders. However, the mechanisms regulating hippocampal development and adult neurogenesis remain unclear. One of the limitations to studying these processes is the scarcity of available specific mouse tools. Here, we report an inducible transgenic Cre mouse line, Frizzled 9‐CreER™, in which tamoxifen administration induces Cre recombinant. Our data show that Cre is expressed in the developing hippocampal primordium, confined to the granule cell layer at P20 and further limited to the subgranular zone in the adult dentate gyrus. Cre recombinase shows very high activity in all of these regions. Thus, this transgenic line will be a powerful tool in understanding the mechanisms of hippocampal development, adult neurogenesis, and associated diseases. genesis 49:919–926, 2011. © 2011 Wiley Periodicals, Inc.
In Vivo labeling of zebrafish motor neurons using an mnx1 enhancer and Gal4/UAS
Authors: Zelenchuk Taras A. , Brusés Juan L. 
Published: April 2011

AbstractThe zebrafish spinal cord primary motor neurons are commonly used as an experimental model to study the molecular mechanisms that regulate axonal pathfinding and neuromuscular junction formation, and for the modeling of human neurodegenerative disorders. This study characterized a 125‐bp mnx1 enhancer to direct gene expression in spinal cord motor neurons. A promoter containing three copies of the 125‐bp mnx1 enhancer was generated in a Tol2 vector and used to drive enhanced green fluorescent protein (EGFP) expression either directly or in combination with the Gal4/UAS transcriptional activation system. Both methods induced protein expression for up to 5 days after fertilization, allowing the observation of the dendritic tree and axonal arborization of single motor neurons within a somitic segment in fixed and live animals. The use of the 125‐bp mnx1 promoter for transient transgenic expression or for the generation of stable transgenic fish lines will facilitate the study of motor neuron development and neurodegenerative processes. genesis 49:543–554, 2011. © 2011 Wiley‐Liss, Inc.