bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of flow and turbulence in the Phoenix area using a modified urbanized mesoscale model
Authors: Park S. Y. , Fernando H. J. S. , Yoon S. C. 
Published: March 2014

ABSTRACTThe urban canopy parameterization (UCP) of Dupont et al. implemented in the MM5v3.7 mesoscale meteorological modelling system (MM5‐UCP‐Basic) is evaluated against the non‐urbanized model (MM5‐NoUCP) using measurements taken in urban Phoenix during two field studies. In general, MM5‐UCP‐Basic improved the predictions of typical meteorological parameters. Nevertheless, significant discrepancies still exist between observations and the predictions of MM5‐UCP‐Basic, and new parameterizations and land‐use classes are introduced to improve the model performance. Anthropogenic heat flux from buildings and roadways is also included. The land‐use classes in the improved model (MM5‐UCP‐MOD) represent roadways and rivers, in addition to five classes of buildings identified in MM5‐UCP‐Basic. New parameterizations include those for momentum roughness, velocity decay during evening transition, and heat and momentum diffusivities for the nocturnal period that account for different heat and momentum transfer rates under stable atmospheric conditions. Five nested grid domains are used for simulations, with the highest resolution (1 km) implemented in the two UCP versions. In general, substantial improvements in the prediction of wind speed, temperature (especially during the night time), and momentum flux as well as a smaller improvement in the heat flux are noted, pointing to possible further enhancement to model performance by including improved physics in the model.
Systematic Identification of Matching Molecular Series and Mapping of Screening Hits
Authors: de la Vega de León Antonio , Hu Ye , Bajorath Jürgen 
Published: March 2014

AbstractMatching molecular series (MMS) have originally been introduced as an extension of the matched molecular pair (MMP) concept to facilitate the design of substructure‐based structure‐activity relationship (SAR) networks. An MMP is defined as a pair of compounds that only differ by a structural change at a single site. In addition, an MMS is defined as an MMP‐based series of compounds that have a conserved structural core and are distinguished by modifications at a single site. Systematic generation of MMS from specifically active compounds generalizes the search for series of structural analogs. Potency‐ordered MMS provide series associated with SAR information. We have systematically extracted MMS from publicly available compounds with well‐defined activity measurements and generated a large database with approx. 40 000 single‐ and 13 600 multi‐target series, which provide a rich source of SAR information. As an application, we introduce MMP‐based mapping of screening hits to MMS to search for initial SAR information and determine all SAR environments available for such hits. The MMS database is made freely available to the scientific community.
Quantification of circumferential, longitudinal, and radial global fractional shortening using steady‐state free precession cines: A comparison with tissue‐tracking strain and application in fabry disease
Authors: Cheng‐Baron June , Chow Kelvin , Pagano Joseph J. , Punithakumar Kumaradevan , Paterson D. Ian , Oudit Gavin Y. , Thompson Richard B. 
Published: March 2014

PurposeConventional calculation of myocardial strain requires tissue‐tracking. A surrogate for strain called global fractional shortening (GFS) is proposed based on changes in dimensions of endocardial and epicardial surfaces without tissue‐tracking.MethodsThree‐dimensional endocardial and epicardial left ventricular surfaces traced at end‐diastole and end‐systole using conventional steady‐state free precession cine images were used to calculate GFScc (circumferential), GFSll (longitudinal), and GFSrr (radial) using fractional length changes in each direction over the heart surface. GFS values were validated using finite element models (FEM) and in vivo using tagging‐derived strains (εcc,εll,εrr) in patients with a wide range of ejection fraction (EF) and diagnosis (n = 32). GFS was also measured in 31 patients with Fabry disease and matched healthy controls.ResultsGFS values were within 3% of average FEM‐derived Lagrangian strains and had good agreement in vivo (GFScc = −14 ± 4%, εcc = −14 ± 4%, R2 = 0.85; GFSll = −12 ± 4%, εll = −12 ± 4%, R2 = 0.72; GFSrr = 46 ± 21%). εrr could not be measured reliably from tagging. Compared with healthy controls with matched EF, patients with Fabry disease had significantly increased GFScc (Endo) (−28 ± 3% versus −25 ± 2%), decreased GFScc(Epi) (−10 ± 2% versus −11 ± 2%) and decreased GFSll for all components.ConclusionGFS yields similar values to conventionally measured strains without requiring tissue‐tracking. Compared with controls, patients with Fabry disease have significant differences in several GFS components. Magn Reson Med 73:586–596, 2015. © 2014 Wiley Periodicals, Inc.
Real‐time feedback for spatiotemporal field stabilization in MR systems
Authors: Duerst Yolanda , Wilm Bertram J. , Dietrich Benjamin E. , Vannesjo S. Johanna , Barmet Christoph , Schmid Thomas , Brunner David O. , Pruessmann Klaas P. 
Published: March 2014

PurposeMR imaging and spectroscopy require a highly stable, uniform background field. The field stability is typically limited by hardware imperfections, external perturbations, or field fluctuations of physiological origin. The purpose of the present work is to address these issues by introducing spatiotemporal field stabilization based on real‐time sensing and feedback control.MethodsAn array of NMR field probes is used to sense the field evolution in a whole‐body MR system concurrently with regular system operation. The field observations serve as inputs to a proportional‐integral controller that governs correction currents in gradient and higher‐order shim coils such as to keep the field stable in a volume of interest.ResultsThe feedback system was successfully set up, currently reaching a minimum latency of 20 ms. Its utility is first demonstrated by countering thermal field drift during an EPI protocol. It is then used to address respiratory field fluctuations in a T2*‐weighted brain exam, resulting in substantially improved image quality.ConclusionFeedback field control is an effective means of eliminating dynamic field distortions in MR systems. Third‐order spatial control at an update time of 100 ms has proven sufficient to largely eliminate thermal and breathing effects in brain imaging at 7 Tesla. Magn Reson Med 73:884–893, 2015. © 2014 Wiley Periodicals, Inc.
Closed‐form solution for T2 mapping with nonideal refocusing of slice selective CPMG sequences
Authors: Petrovic Andreas , Scheurer Eva , Stollberger Rudolf 
Published: March 2014

PurposeT2 quantification with multiecho sequences is typically impaired by the contribution of stimulated echoes to the echo decay due to B1+ inhomogeneity and slice profile effects. In this work, a compact signal model based on the generating functions approach, which accounts for both sources of error, is presented.MethodsThe generating functions (GF) approach is used to obtain a closed solution to the evolution of the transverse magnetization in an echo train, however, not in the time domain, but in the transformed z‐domain. The approach is generalized by the incorporation of flip angle distribution across the refocusing slice profiles. The approach is tested by fitting the model to simulated data as well as to phantom and in vivo measurements, followed by a comparison with the common monoexponential fitting approach.ResultsThe fitting simulations indicate that T2 errors of up to 30% can be commonplace in a clinical setting using the monoexponential method. Conversely, the GF approach produced accurate results. Phantom and in vivo experiments showed a good agreement of the GF values with spectroscopic measurements and single‐echo spin‐echo sequences.ConclusionA correction for stimulated echoes is necessary to compute comparable T2 values. The presented approach provides a solution to this issue. Magn Reson Med 73:818–827, 2015. © 2014 Wiley Periodicals, Inc.
N‐Aryl Isoleucine Derivatives as Angiotensin II AT2 Receptor Ligands
Authors: Behrends Malte , Wallinder Charlotta , Wieckowska Anna , Guimond Marie-Odile , Hallberg Anders , Gallo-Payet Nicole , Larhed Mats 
Published: March 2014

AbstractA novel series of ligands for the recombinant human AT2 receptor has been synthesized utilizing a fast and efficient palladium‐catalyzed procedure for aminocarbonylation as the key reaction. Molybdenum hexacarbonyl [Mo(CO)6] was employed as the carbon monoxide source, and controlled microwave heating was applied. The prepared N‐aryl isoleucine derivatives, encompassing a variety of amide groups attached to the aromatic system, exhibit binding affinities at best with Ki values in the low micromolar range versus the recombinant human AT2 receptor. Some of the new nonpeptidic isoleucine derivatives may serve as starting points for further structural optimization. The presented data emphasize the importance of using human receptors in drug discovery programs.
Low carbohydrate diet to achieve weight loss and improve HbA1c in type 2 diabetes and pre‐diabetes: experience from one general practice
Authors: Unwin David , Unwin Jen 
Published: March 2014

AbstractPatients with diabetes have long been exhorted to give up sugar, encouraged instead to take in fuel as complex carbohydrate such as the starch found in bread, rice or pasta (especially if ‘wholemeal’). However, bread has a higher glycaemic index than table sugar itself. There are no essential nutrients in starchy foods and people with diabetes struggle to deal with the glycaemic load they bring. The authors question why carbohydrate need form a major part of the diet at all. The central goal of achieving substantial weight loss has tended to be overlooked. The current pilot study explores the results of a low carbohydrate diet for a case series of 19 type 2 diabetes and pre‐diabetes patients over an eight‐month period in a suburban general practice.A low carbohydrate diet was observed to bring about major benefits. Blood glucose control improved (HbA1c 51±14 to 40±4mmol/mol; p<0.001). By the end of the study period only two patients remained with an abnormal HbA1c (>42mmol/mol); even these two had seen an average drop of 23.9mmol/mol. Weight fell from 100.2±16.4 to 91.0±17.1kg (p<0.0001), and waist circumference decreased from 120.2±9.6 to 105.6±11.5cm (p<0.0001). Simultaneously, blood pressure improved (systolic 148±17 to 133±15mmHg, p<0.005; and diastolic 91±8 to 83±11mmHg, p<0.05). Serum gamma‐glutamyltransferase decreased from 75.2±54.7 to 40.6±29.2 U/L (p<0.005). Total serum cholesterol decreased from 5.5±1.0 to 4.7±1.2mmol/L (p<0.01).This approach is easy to implement in general practice, and brings rapid weight loss and improvement in HbA1c. Copyright © 2014 John Wiley & Sons. Practical Diabetes 2014; 31(2): 76–79
Can Tolerant Diatom Taxa be Used for Effective Assessments of Human Pressure?
Authors: Szczepocka E. , Kruk A. , Rakowska B. 
Published: March 2014

AbstractBecause lately the low bioindicative value of tolerant species from different taxonomic groups is often questioned, in this study, we hypothesized that tolerant diatoms may be used for effective temporal assessments of human pressure. We tested this on the lowland Bzura River in central Poland, on 156 diatom samples (DSs) from two study periods of 1972 with extremely severe point‐source water pollution and of 2002–2004, where the complex wastewater management in the river catchment improved water quality considerably. Out of the total 295 diatom species recorded in the samples, only 133 tolerant ones were included in the study. Patterns in their abundance were recognized with a Kohonen artificial neural network (self‐organizing map, SOM), whereas the species significantly associated with each SOM cluster of diatom samples were identified with the indicator value (IndVal) index and the Monte Carlo test. If the hypothesis tested was not supported, the assignation of DSs to the SOM clusters would be random. However, the separation of DSs from 1972 and 2002–2004 was almost perfect because the number of exceptions was as low as 4.5%. In addition, the relatively high number (64 out of 133) of tolerant species significantly associated with any SOM cluster (and respective environmental conditions at sites from which samples assigned to it come) supports the hypothesis tested. This means that almost half of the studied species are not evenly distributed in particular clusters as might be expected for highly tolerant species. The study proves that the abundances of many diatom species, currently classified as tolerant, carry quite precise information on the differences in the quality of the environment, and indicates those tolerant diatom species whose bioindicative potential may be highest. Copyright © 2014 John Wiley & Sons, Ltd.
Super‐light concrete decks for building floor slabs
Authors: Hertz Kristian , Castberg Andreas , Christensen Jacob 
Published: March 2014

AbstractThis paper presents investigations carried out at the Technical University of Denmark (DTU) on a prototype series for a super‐lightweight prestressed concrete deck element called the SL‐Deck.The intention behind making a new prefabricated deck element is to improve performance with respect to flexibility, sound insulation and fire resistance compared with present‐day prefabricated structures.Full‐scale tests and theoretical investigations show that the deck structure performs as intended. Also, that it is possible to assess by calculation the loadbearing capacity in bending and shear, and assess the pull‐out strength of prestressing wires, the fire resistance and the acoustic insulation. Based on the results of the investigations, recommendations are given for further development of the structure before fully automated mass production is established.
Consistent practical design of concrete structures
Authors: Nyhus Bente Skovseth 
Published: March 2014

AbstractThe design of large concrete structures is a very complex area which requires specialized skills and specialized tools. Tools are available to design these structures efficiently. However, these design tools are based on inconsistency between what is assumed in the structural analysis and the sectional design. This inconsistency is believed to be conservative, but is such an approach always safe and cost‐effective? In light of this, a design tool has been developed to eliminate this inconsistency. The program is called ShellDesign and the new method is called the “consistent stiffness method”. The method can be used in practical design and is a more efficient alternative to running non‐linear analysis programs. In order to obtain a more rational and consistent design method for transverse shear, implementation of the modified compression field theory (MCFT) in ShellDesign is almost finished. The main advantages of developing ShellDesign are to increase the competitiveness of concrete structures, contribute to increased safety and also to increase operability and document robustness in existing structures.
Dynamically loaded concrete structures – monitoring‐based assessment of the real degree of fatigue deterioration
Authors: Urban Susanne , Strauss Alfred , Schütz Robert , Bergmeister Konrad , Dehlinger Christian 
Published: March 2014

AbstractWhen it comes to dynamically loaded concrete structures, determining the real degree of fatigue damage of a structure on site is a very demanding process that has not been explored in depth. Calculation concepts according to current codes and specifications (e.g. fib Model Code for Concrete Structures 2010 [1]) do not offer efficient results for this task. However, the permanent monitoring from the erection of a structure up to the end of its lifetime is seen as a very promising possibility for assessing the degree of damage constantly. This article takes a closer look at the concrete fatigue concept of fib Model Code 2010 [1], shows an FE simulation of a time‐dependent fatigue process for an offshore wind turbine foundation and presents a fatigue monitoring concept including laboratory tests, which enables the detection of the real degree of deterioration in a concrete structure. During tests, the use of ultrasound was identified as the most appropriate method. Measuring wave velocity enables the determination of the dynamic E‐modulus, which correlates to the degree of damage within the cross‐section of the structure considered.
A Flexible Tri‐carboxylic Acid Derived Zinc(II) 3D Helical Metal‐Organic‐Framework and a Cadmium(II) Interwoven 2D Layered Framework Solid
Authors: Vishnoi Pratap , Murugavel Ramaswamy 
Published: March 2014

Abstract Starting from a flexible tri‐carboxylic acid ligand H3L {H3L = 2,4,6‐tris[(4′‐carboxyphenoxy)methyl]‐1,3,5‐trimethylbenzene}, a 3D metal‐organic framework [Zn(HL)(H2O)]n (1) and a 2D polymeric layered solid {[(CH3)2NH2)]2[Cd2L2(DMA)2]}n (2) were hydrothermally synthesized. The complexes were characterized by elemental analyses, FT‐IR spectroscopy, TGA, and single‐crystal X‐ray diffraction. The X‐ray structural analyses reveal that the complex 1 is an example of a doubly interpenetrated 3D helical MOF with mutually entwined right‐ and left‐handed helices to form an overall racemic framework. Complex 2 is made up of fourfold interwoven 2D nets in the solid state.
Comparison of outcomes between operative vaginal deliveries and spontaneous vaginal deliveries in southeast Nigeria
Authors: Lawani Lucky O. , Anozie Okechukwu B. , Ezeonu Paul O. , Iyoke Chukwuemeka A. 
Published: March 2014

AbstractObjectiveTo evaluate the incidence of, indications for, and outcome of operative vaginal deliveries compared with spontaneous vaginal deliveries in southeast Nigeria.MethodsA retrospective cohort study was conducted involving cases of operative vaginal delivery performed at Ebonyi State University Teaching Hospital over a 10‐year period. Data on the procedures were abstracted from the operation notes of the medical records of parturients.ResultsAn incidence of 4.7% (n = 461) was recorded. The most common indications for vacuum and forceps delivery were prolonged second stage of labor (44.9%) and poor maternal effort (27.8%). The only indication for destructive operation was intrauterine fetal death (3.7%). The risk ratio (RR) for hemorrhage/vulvar hematoma was 1.14 (95% confidence interval [CI], 0.53–2.48) for vacuum‐assisted delivery and 5.49 (95% CI, 0.82–36.64) for forceps delivery. The RR for genital laceration was 1.21 (95% CI, 0.44–3.30) for vacuum‐assisted delivery and 9.41 (95% CI, 1.33–66.65) for forceps delivery. The risk of fetal scalp bruises and caput succedaneum was higher for operative vaginal delivery than for spontaneous vaginal delivery, with no significant difference in maternal morbidity. The perinatal mortality rate was 0.9 per 1000 live births.ConclusionOperative vaginal delivery by experienced healthcare providers is associated with good obstetric outcomes with minimal risk.
Gelfand pairs and strong transitivity for Euclidean buildings
Authors: CAPRACE PIERRE-EMMANUEL , CIOBOTARU CORINA 
Published: March 2014

AbstractLet $G$ be a locally compact group acting properly, by type-preserving automorphisms on a locally finite thick Euclidean building $\Delta $, and $K$ be the stabilizer of a special vertex in $\Delta $. It is known that $(G, K)$ is a Gelfand pair as soon as $G$ acts strongly transitively on $\Delta $; in particular, this is the case when $G$ is a semi-simple algebraic group over a local field. We show a converse to this statement, namely that if $(G, K)$ is a Gelfand pair and $G$ acts cocompactly on $\Delta $, then the action is strongly transitive. The proof uses the existence of strongly regular hyperbolic elements in $G$ and their peculiar dynamics on the spherical building at infinity. Other equivalent formulations are also obtained, including the fact that $G$ is strongly transitive on $\Delta $ if and only if it is strongly transitive on the spherical building at infinity.
Extended Squire’s transformation and its consequences for transient growth in a confined shear flow
Authors: John Soundar Jerome J. , Chomaz Jean-Marc 
Published: March 2014

AbstractThe classical Squire transformation is extended to the entire eigenfunction structure of both Orr–Sommerfeld and Squire modes. For arbitrary Reynolds numbers $\mathit{Re}$, this transformation allows the solution of the initial-value problem for an arbitrary three-dimensional (3D) disturbance via a two-dimensional (2D) initial-value problem at a smaller Reynolds number $\mathit{Re}_{2D}$. Its implications for the transient growth of arbitrary 3D disturbances is studied. Using the Squire transformation, the general solution of the initial-value problem is shown to predict large-Reynolds-number scaling for the optimal gain at all optimization times $t$ with ${t}/{\mathit{Re}}$ finite or large. This result is an extension of the well-known scaling laws first obtained by Gustavsson (J. Fluid Mech., vol. 224, 1991, pp. 241–260) and Reddy & Henningson (J. Fluid Mech., vol. 252, 1993, pp. 209–238) for arbitrary $\alpha \mathit{Re}$, where $\alpha $ is the streamwise wavenumber. The Squire transformation is also extended to the adjoint problem and, hence, the adjoint Orr–Sommerfeld and Squire modes. It is, thus, demonstrated that the long-time optimal growth of 3D perturbations as given by the exponential growth (or decay) of the leading eigenmode times an extra gain representing its receptivity, may be decomposed as a product of the gains arising from purely 2D mechanisms and an analytical contribution representing 3D growth mechanisms equal to $1+ \left (\beta \mathit{Re}/\mathit{Re}_{2D}\right )^2 \mathcal{G}$, where $\beta $ is the spanwise wavenumber and $\mathcal{G}$ is a known expression. For example, when the leading eigenmode is an Orr–Sommerfeld mode, it is given by the product of respective gains from the 2D Orr mechanism and an analytical expression representing the 3D lift-up mechanism. Whereas if the leading eigenmode is a Squire mode, the extra gain is shown to be solely due to the 3D lift-up mechanism. Direct numerical solutions of the optimal gain for plane Poiseuille and plane Couette flow confirm the novel predictions of the Squire transformation extended to the initial-value problem. These results are also extended to confined shear flows in the presence of a temperature gradient.
On the Instability of Plane Poiseuille Flow of Two Immiscible Fluids Using the Energy Gradient Theory
Authors: Farahbakhsh I. , Nourazar S. S. , Ghassemi H. , Dou H.-S. , Nazari-Golshan A. 
Published: March 2014

ABSTRACTIn the present study, the instability of laminar flow of two immiscible fluids is investigated. The theory of energy gradient is employed for the analysis. The distributions of energy gradient for various viscosity ratios, i.e., ratios of lower viscosity to higher one, are obtained and the results for the onset of instability are compared with the available experimental data. The comparison of the results shows excellent agreement with the existing experimental data. It will be also demonstrated that as the viscosity ratio decreases the flow becomes more stable even at high Reynolds numbers.