bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic review on the effect of sweeteners on glycemic response and clinically relevant outcomes
Authors: Wiebe Natasha , Padwal Raj , Field Catherine , Marks Seth , Jacobs Rene , Tonelli Marcello
Published: February 2012

Background

The major metabolic complications of obesity and type 2 diabetes may be prevented and managed with dietary modification. The use of sweeteners that provide little or no calories may help to achieve this objective.

Methods

We did a systematic review and network meta-analysis of the comparative effectiveness of sweetener additives using Bayesian techniques. MEDLINE, EMBASE, CENTRAL and CAB Global were searched to January 2011. Randomized trials comparing sweeteners in obese, diabetic, and healthy populations were selected. Outcomes of interest included weight change, energy intake, lipids, glycated hemoglobin, markers of insulin resistance and glycemic response. Evidence-based items potentially indicating risk of bias were assessed.

Results

Of 3,666 citations, we identified 53 eligible randomized controlled trials with 1,126 participants. In diabetic participants, fructose reduced 2-hour blood glucose concentrations by 4.81 mmol/L (95% CI 3.29, 6.34) compared to glucose. Two-hour blood glucose concentration data comparing hypocaloric sweeteners to sucrose or high fructose corn syrup were inconclusive. Based on two ≤10-week trials, we found that non-caloric sweeteners reduced energy intake compared to the sucrose groups by approximately 250-500 kcal/day (95% CI 153, 806). One trial found that participants in the non-caloric sweetener group had a decrease in body mass index compared to an increase in body mass index in the sucrose group (-0.40 vs 0.50 kg/m2, and -1.00 vs 1.60 kg/m2, respectively). No randomized controlled trials showed that high fructose corn syrup or fructose increased levels of cholesterol relative to other sweeteners.

Conclusions

Considering the public health importance of obesity and its consequences; the clearly relevant role of diet in the pathogenesis and maintenance of obesity; and the billions of dollars spent on non-caloric sweeteners, little high-quality clinical research has been done. Studies are needed to determine the role of hypocaloric sweeteners in a wider population health strategy to prevent, reduce and manage obesity and its consequences.
Cardiopulmonary resuscitation traumatic cardiac arrest - there are survivors. An analysis of two national emergency registries
Authors: Gräsner Jan-Thorsten , Wnent Jan , Seewald Stephan , Meybohm Patrick , Fischer Matthias , Paffrath Thomas , Wafaisade Arasch , Bein Berthold , Lefering Rolf ,   German Resuscitation Registry Working Group, Trauma Registry of the German Society for Trauma Surgery (DGU)
Published: February 2012

Introduction

Cardiac arrest following trauma occurs infrequently compared with cardiac aetiology. Within the German Resuscitation Registry a traumatic cause is documented in about 3% of cardiac arrest patients. Regarding the national Trauma Registry, only a few of these trauma patients with cardiac arrest survive. The aim of the present study was to analyze the outcome of cardiopulmonary resuscitation (CPR) after traumatic cardiac arrest by combining data from two different large national registries in Germany.

Methods

This study includes 368 trauma patients (2.8%) out of 13,329 cardiac arrest patients registered within the Resuscitation Registry, whereby 3,673 patients with a cardiac cause and successful CPR served as a cardiac control group. We further analyzed a second group of 1,535 trauma patients with cardiac arrest and early CPR registered within the Trauma Registry, whereby a total of 25,366 trauma patients without any CPR attempts served as a trauma control group. The relative frequencies from each database were used to calculate relative percentages for patients with traumatic cardiac arrest in whom resuscitation was attempted.

Results

Within the Resuscitation Registry, cardiac arrest was present in 331 patients (89.9%) when the EMS personal arrived at the scene and in 37 patients (10.1%) when cardiac arrest occurred after arrival. Spontaneous circulation could be achieved in 107 patients (29.1%). A total of 101 (27.4%) were transferred to hospital, 95 of whom (25.8%) had return of spontaneous circulation (ROSC) on admission. According to the Trauma Registry, the overall hospital mortality rate for cardiac arrest patients following trauma was 73% (n = 593 of 814). About half of the patients who were admitted alive to hospital died within 24 hours, resulting in 13% survivors within 24 hours. 7% of the patients survived until hospital discharge, and only 2% of the patients had good neurological outcome.

Conclusions

Our present study encourages CPR attempts in cardiac arrest patients following severe trauma. When a manageable number of patients is present, the decision on whether to start CPR or not should be done liberally, using comparable criteria as in patients with cardiac etiology. In this respect, trauma management programs that restrict CPR attempts should not be encouraged.
Elastic-wavefield interferometry using P-wave source VSPs at the Wamsutter field, Wyoming
Authors: Gaiser James , Vasconcelos Ivan , Geetan Rosemarie , Faragher John
Published: February 2012

In this study, elastic-wavefield interferometry was used to recover P- and S-waves from the 3D P-wave vibrator VSP data at Wamsutter field in Wyoming. S-wave velocity and birefringence is of particular interest for the geophysical objectives of lithology discrimination and fracture characterization in naturally fractured tight gas sand reservoirs. Because we rely on deconvolution interferometry for retrieving interreceiver P- and S-waves in the subsurface, the output fields are suitable for high-resolution, local reservoir characterization. In 1D media where the borehole is nearly vertical, data at the stationary-phase point is not conducive to conventional interferometry. Strong tube-wave noise generated by physical sources near the borehole interfere with S-wave splitting analyses. Also, converted P- to S-wave (PS-wave) polarity reversals occur at zero offset and cancel their recovery. We developed methods to eliminate tube-wave noise by removing physical sources at the stationary-phase point and perturbing the integration path in the integrand based on P-wave NMO velocity of the direct-arrival. This results in using nonphysical energy outside a Fresnel radius that could not have propagated between receivers. To limit the response near the stationary-phase point, we also applied a weighting condition to suppress energy from large offsets. For PS-waves, a derivative-like operator was applied to the physical sources at zero offset in the form of a polarity reversal. These methods resulted in effectively recovering P-wave dipole and PS-wave quadrupole pseudosource VSPs. The retrieved wavefields kinematically correspond to a vertical incidence representation of reflectivity/transmissivity and can be used for conventional P- and S-wave velocity analyses. Four-component PS-wave VSPs retrieve S-wave splitting in transmitted converted waves that provide calibration for PS-wave and P-wave azimuthal anisotropy measurements from surface-seismic data.
Seismic data interpolation and denoising in the frequency-wavenumber domain
Authors: Naghizadeh Mostafa
Published: February 2012

I introduce a unified approach for denoising and interpolation of seismic data in the frequency-wavenumber ([Formula: see text]) domain. First, an angular search in the [Formula: see text] domain is carried out to identify a sparse number of dominant dips, not only using low frequencies but over the whole frequency range. Then, an angular mask function is designed based on the identified dominant dips. The mask function is utilized with the least-squares fitting principle for optimal denoising or interpolation of data. The least-squares fit is directly applied in the time-space domain. The proposed method can be used to interpolate regularly sampled data as well as randomly sampled data on a regular grid. Synthetic and real data examples are provided to examine the performance of the proposed method.
Migration and autism spectrum disorder: population-based study
Authors: Magnusson Cecilia , Rai Dheeraj , Goodman Anna , Lundberg Michael , Idring Selma , Svensson Anna , Koupil Ilona , Serlachius Eva , Dalman Christina
Published: February 2012

Background

Migration has been implicated as a risk factor for autism, but evidence is limited and inconsistent.

Aims

To investigate the relationship between parental migration status and risk of autism spectrum disorder, taking into consideration the importance of region of origin, timing of migration and possible discrepancies in associations between autism subtypes.

Method

Record-linkage study within the total child population of Stockholm County between 2001 and 2007. Individuals with high- and low-functioning autism were defined as having autism spectrum disorder with and without comorbid intellectual disability, and ascertained via health and habilitation service registers.

Results

In total, 4952 individuals with autism spectrum disorder were identified, comprising 2855 children with high-functioning autism and 2097 children with low-functioning autism. Children of migrant parents were at increased risk of low-functioning autism (odds ratio (OR) = 1.5, 95% CI 1.3–1.7); this risk was highest when parents migrated from regions with a low human development index, and peaked when migration occurred around pregnancy (OR = 2.3, 95% CI 1.7–3.0). A decreased risk of high-functioning autism was observed in children of migrant parents, regardless of area of origin or timing of migration. Parental age, income or obstetric complications did not fully explain any of these associations.

Conclusions

Environmental factors associated with migration may contribute to the development of autism presenting with comorbid intellectual disability, especially when actingin utero.High- and low-functioning autism may have partly different aetiologies, and should be studied separately.
Trajectories of trauma symptoms and resilience in deployed US military service members: Prospective cohort study
Authors: Bonanno George A. , Mancini Anthony D. , Horton Jaime L. , Powell Teresa M. , LeardMann Cynthia A. , Boyko Edward J. , Wells Timothy S. , Hooper Tomoko I. , Gackstetter Gary D. , Smith Tyler C. ,   For the Millennium Cohort Study Team
Published: February 2012

Background

Most previous attempts to determine the psychological cost of military deployment have been limited by reliance on convenience samples, lack of pre-deployment data or confidentiality and cross-sectional designs.

Aims

This study addressed these limitations using a population-based, prospective cohort of US military personnel deployed in support of the operations in Iraq and Afghanistan.

Method

The sample consisted of US military service members in all branches including active duty, reserve and national guard who deployed once (n= 3393) or multiple times (n= 4394). Self-reported symptoms of post-traumatic stress were obtained prior to deployment and at two follow-ups spaced 3 years apart. Data were examined for longitudinal trajectories using latent growth mixture modelling.

Results

Each analysis revealed remarkably similar post-traumatic stress trajectories across time. The most common pattern was low–stable post-traumatic stress or resilience (83.1% single deployers, 84.9% multiple deployers), moderate–improving (8.0%, 8.5%), then worsening–chronic posttraumatic stress (6.7%, 4.5%), high–stable (2.2% single deployers only) and high–improving (2.2% multiple deployers only). Covariates associated with each trajectory were identified.

Conclusions

The final models exhibited similar types of trajectories for single and multiple deployers; most notably, the stable trajectory of low post-traumatic stress pre- to post-deployment, or resilience, was exceptionally high. Several factors predicting trajectories were identified, which we hope will assist in future research aimed at decreasing the risk of post-traumatic stress disorder among deployers.
Lola regulates glutamate receptor expression at the Drosophila neuromuscular junction
Authors: Fukui Ai , Inaki Mikiko , Tonoe Gaku , Hamatani Hiroki , Homma Mizuho , Morimoto Takako , Aburatani Hiroyuki , Nose Akinao
Published: February 2012

Communication between pre- and post-synaptic cells is a key process in the development and modulation of synapses. Reciprocal induction between pre- and postsynaptic cells involves regulation of gene transcription, yet the underlying genetic program remains largely unknown. To investigate how innervation-dependent gene expression in postsynaptic cells supports synaptic differentiation, we performed comparative microarray analysis of Drosophila muscles before and after innervation, and of prospero mutants, which show a delay in motor axon outgrowth. We identified 84 candidate genes that are potentially up- or downregulated in response to innervation. By systematic functional analysis, we found that one of the downregulated genes, longitudinals lacking (lola), which encodes a BTB-Zn-finger transcription factor, is required for proper expression of glutamate receptors. When the function of lola was knocked down in muscles by RNAi, the abundance of glutamate receptors (GluRs), GluRIIA, GluRIIB and GluRIII, as well as that of p-21 activated kinase (PAK), was greatly reduced at the neuromuscular junctions (NMJs). Recordings of the synaptic response revealed a decrease in postsynaptic quantal size, consistent with the reduction in GluR levels. Lola appears to regulate the expression of GluRs and PAK at the level of transcription, because the amount of mRNAs encoding these molecules was also reduced in the mutants. The transcriptional level of lola, in turn, is downregulated by increased neural activity. We propose that Lola coordinates expression of multiple postsynaptic components by transcriptional regulation.
Flower-deficient mice have reduced susceptibility to skin papilloma formation
Authors: Petrova Evgeniya , López-Gay Jesús M. , Rhiner Christa , Moreno Eduardo
Published: February 2012

Skin papillomas arise as a result of clonal expansion of mutant cells. It has been proposed that the expansion of pretumoral cell clones is propelled not only by the increased proliferation capacity of mutant cells, but also by active cell selection. Previous studies in Drosophila describe a clonal selection process mediated by the Flower (Fwe) protein, whereby cells that express certain Fwe isoforms are recognized and forced to undergo apoptosis. It was further shown that knock down of fwe expression in Drosophila can prevent the clonal expansion of dMyc-overexpressing pretumoral cells. Here, we study the function of the single predicted mouse homolog of Drosophila Fwe, referred to as mFwe, by clonal overexpression of mFwe isoforms in Drosophila and by analyzing mFwe knock-out mice. We show that clonal overexpression of certain mFwe isoforms in Drosophila also triggers non-autonomous cell death, suggesting that Fwe function is evolutionarily conserved. Although mFwe-deficient mice display a normal phenotype, they develop a significantly lower number of skin papillomas upon exposure to DMBA/TPA two-stage skin carcinogenesis than do treated wild-type and mFwe heterozygous mice. Furthermore, mFwe expression is higher in papillomas and the papilloma-surrounding skin of treated wild-type mice compared with the skin of untreated wild-type mice. Thus, we propose that skin papilloma cells take advantage of Fwe activity to facilitate their clonal expansion.
Antineutrophil cytoplasmic antibodies: two cases of changing antigenic specificity
Authors: Saleem Rehana , Oliver Michael , Rowbottom Anthony , Solomon Laurie
Published: February 2012

The transformation of the antineutrophil cytoplasmic antibody (ANCA) specificity in the absence of specific drug treatment has not been reported in the literature. A few studies have suggested changes in the epitopes recognized by the ANCAs. We describe two patients who switched from myeloperoxidase-positive to PR3 (proteinase 3)-positive ANCA during the course of their disease process and subsequently remained unchanged. One patient developed ulcerative colitis following the appearance of PR3-ANCA while the other remains quiescent. Regular follow-up and close monitoring of ANCA specificity are essential. A change of specificity may indicate the development of a new ANCA-related disease.
Selection of Input Variables for the Prediction of Wind Speed in Wind Farms Based on Genetic Algorithm
Authors: Gupta R. A. , Kumar Rajesh , Bansal Ajay Kumar
Published: February 2012

Wind power generation is increasing very rapidly all around the world. The available wind energy depends on the wind speed, which is a random variable and depends on the location and weather conditions. For the wind-farm operator, this uncertainty creates difficulty in the system scheduling and energy dispatching. Due to this there is a need for predicting the wind speed, i.e., power in advance. The first consideration in predictive wind speed is the selection of appropriate input variables. Many variables are available for wind speed prediction, and some of them cannot be omitted without a significant loss of information. The collection of field data, on the other hand, is both time-consuming and expensive. This becomes more complex and costly as the number of variable's increases. Due to this, rigorous methods are needed to detect which variables are essential and important and, which are not. Appropriate selection of input variables is not only important for modeling objectives as such, but also to ensure reliable decision-support in unit commitment and energy policy-making. In this paper, application of genetic algorithms is explored to automatically select the relevant input variables for Artificial Neural Networks (ANNs). The applied database consisted of 12 different variables, which are measured from Jaipur (Rajasthan). The measured variables are a combination of temperature, wind and atmospheric. The genetic algorithm selects different combinations of input variables and applies them to back-propagation ANN network for wind speed prediction. The ANN predicts the wind speed using the selected variable set and then the various combinations are compared based on their predictive power. With this technique, the number of input variables could be reduced from 13 to 8. In addition, the prediction success increases by the maximum 5 percent. The data requirement, calculation time, memory requirement, complexity of the ANN, cost of measuring equipments, etc. reduces due to removal of irrelevant data from the process.
Stability Margin of DFIG Wind Turbines: Effects and Solutions
Authors: Tennakoon Ajith P. , Ekanayake Janaka B. , Atputharajah Arulampalam , Abeyratne Sunil G.
Published: February 2012

Doubly Fed Induction Generator (DFIG) based wind farms are one of the major contributors to wind power generation. Even though they possess advantages such as the capability of generating active power over an extended range of speed and the reduction of mechanical stresses in the turbine and the coupling, achieving maximum power extraction at high wind speeds while satisfying the present grid code requirements is a major issue. This is because the stability of the DFIG imposes a limitation on extracting maximum power at super synchronous speeds.

An operating chart of the DFIG has been derived incorporating a steady state stability margin for safe operation. The PI limits of the active (P) and reactive (Q) power controllers have been derived by considering stator current, the rotor side converter power ratings and the stability margin of the generator. Studies also have been carried out to investigate what factors could be considered to improve the P and Q capability of the DFIG wind turbine.
Decoupled Power Control of Doubly-Fed Induction Generator Based on an Implicit Position and Speed Estimation Algorithm without the Flux Computation
Authors: Karthikeyan A. , Nagamani C.
Published: February 2012

Owing to the increased attention on the need for deployment of renewable energy sources such as the wind energy, there is a growing interest in Doubly Fed Induction Generators (DFIG) which are suitable for variable speed constant frequency generation. Accurate information of the rotor position with respect to the stator is central to the effective decoupled control of real and reactive power in the DFIG. Typically sensorless estimation of the rotor position involves complex signal processing. This paper presents the implementation of a simple and implicit sensorless algorithm for estimating the rotor position and speed for decoupled control of the doubly-fed induction generator. The proposed algorithm does not involve the computation of stator magnetic flux directly or indirectly using the voltage integration, recursive techniques, re-computations or programmable low pass filters etc. Instead, it employs simple analytical equivalents for the resolved components of the stator flux which are derived from the basic equations governing the machine operation. Since the flux terms are replaced with other equivalent terms, the estimation process is devoid of computing any flux terms and requires only the measured stator voltage and the currents in stator and rotor windings apart from the machine parameters. Starting on the fly, accurate estimation near synchronous speed, immunity against variation in stator and rotor resistances or in the magnetizing inductance are the principal advantages of the algorithm. Reduced complexity and the computational burden facilitate the easy implementation of the algorithm on a low cost fixed point processor. Excellent agreement between the simulation and test results on a laboratory doubly-fed induction machine validates the proposed estimation algorithm. Further MATLAB/Simulink based simulation results are presented to validate the efficacy of the position estimation algorithm based vector control of a doubly-fed induction generator.
Retrofitting of Vulnerable Reinforced Concrete Frames with Wet-Mixed Shotcrete Panels
Authors: Teymur P. , Pala S. , Yuksel E.
Published: February 2012

In this paper, wet-mixed shotcrete panels are proposed instead of reinforced concrete (RC) shear walls for the retrofitting of vulnerable RC frames. The general behavior of the retrofitted frames responding in-plane lateral loading is investigated in detail. The experimental work is composed of retrofitting of undamaged and damaged RC frames. Nearly 1/2 scale, one bay and one story specimens were tested under external loads simulating earthquake effects. To assess the effectiveness of the technique, the results of the retrofitted frames were also compared with a bare frame's and a conventional shear wall retrofitted frame's. The experimental study shows that the wet-mixed shotcrete panels added to vulnerable RC buildings increases the lateral load carrying capacity, the lateral rigidity and the energy dissipation capacity of the system. It is considered that the technique can be used as an efficient, practical and cost effective method in retrofitting of existing vulnerable RC buildings.
Failure Initiation of Reinforced-Concrete Beam-Column Connections — Binomial Logistic Regression Based Probabilistic Model
Authors: Mitra Nilanjan
Published: February 2012

The inelastic mechanisms leading to failure (characterized by strength degradation) initiation in a weak-beam-strong-column reinforced concrete beam-column (RCBC) frame connection subjected to seismic loading are either non-ductile joint failure prior to beam yielding or a ductile mechanism of beam yielding followed by joint failure. Using an extensive assembled database of interior and exterior beam-column joints, binomial logistic regression models are developed to provide a probabilistic estimate of qualitative inelastic mechanisms based on quantitative design parameters obtained from specimen material and geometry. The relative importance of these quantitative parameters is also quantified in this research. The models provide opportunity to an engineer designing new connection to modify geometrical and/or material parameters to obtain ductile mode of response; an engineer retrofitting damaged connection to obtain an understanding of factors influencing initiation of strength degradation and thereby develop suitable retrofit measures for similar connections at eminent risk of failure.
Lessons from the Collapse of Typical RC Frames in Xuankou School during the Great Wenchuan Earthquake
Authors: Lu Xin-Zheng , Ye Lie-Ping , Ma Yu-Hu , Tang Dai-Yuan
Published: February 2012

The seismic damage of typical reinforced concrete (RC) frames in Xuankou School during the Great Wenchuan Earthquake in China is introduced. A simulation method for the seismic damage sustained was developed to enable analysis of the damage mechanisms. The simulation makes use of different nonlinear finite element (FE) models, including macro-scale fibre-beam-element models and a micro-macro-scale hybrid model. The results of the nonlinear FE simulations show that the design of RC frames do not properly allow for the influence of slabs and footing rotations, which results in incorrect predictions of the internal forces and hence, the seismic damage. The collapse resistances of different buildings are compared using incremental dynamic analysis (IDA). The IDA results show that the collapse resistance of the classroom buildings is much lower than that of the office buildings because the larger axial load ratio in classroom buildings limits their lateral deformation capacity. An optimum design is proposed which would improve the collapse resistances of classroom buildings at very low cost.
Structural Behavior of Waffle-Shaped Precast Concrete Panels for Floor Systems
Authors: Cho Seung-Ho , Chung Lan , Lee Sang-Hyun , Heo Seok-Jae , Choi Kyoung-Kyu
Published: February 2012

A waffle-shaped precast concrete panel named WAS has been newly developed as a floor system. Compared to the conventional double tee (DT), the WAS has a more spacious connection area between the panels while having a shallower depth, which possibly results in an enhanced performance of the connection. Experimental studies were performed to examine the flexural behavior of the WAS according to several primary parameters: the panel types, prestress levels applied to the panels, panel sizes, and the existence of steel ties. Connection tests were also performed on the short and long edges of each panel against out-of-plane shear. The test results showed that the WAS panels yields satisfactory flexural capacity similar to the DT up to ultimate state, and they satisfy the deflection limit for serviceability while their stiffnesses were less than those of DT panels. It was also found that the ultimate flexural strength of the WAS panel increases as the applied prestress increases, and that the connections can undertake the applied bending moment and properly transfer the developed shear force between WAS panels. The enhanced performance of the WAS connection makes it possible to efficiently design the panels addressing the moment distribution, and to enhance the serviceability (less deflection and cracking) and structural continuity/integrity of the WAS system while still being able to reduce its depth.
Statistical Analysis of Debonding Load in Concrete Elements Externally Strengthened with CFRP Materials
Authors: Ceroni Francesca , Pecce Marisa
Published: February 2012

An overview of the main items about bond tests for concrete elements externally strengthened with Carbon Fiber Reinforced Plastic (CFRP) materials is presented. Firstly, the effect of set-up on results of bond tests is analysed; then the experimental results of a wide database of bond tests collected by the Authors are compared with some literature provisions in order to point out the reliability of the examined strength models and evidence the role of the set-up. Furthermore, a general procedure for developing design strength models has been applied to determine the bond strength of FRP externally reinforced concrete elements. A bond strength model based on the fracture energy approach is proposed and statistical analyses have been developed in order to calibrate numerical factors. Thus, mean and characteristic provisions for the debonding load in concrete elements externally bonded with CFRP materials are furnished.
A Numerical Criterion to Detect Vertical Stiffness Irregularity
Authors: Aghdam A.Y. , Tariverdilo S.
Published: February 2012

Different seismic codes propose different criteria to detect vertical stiffness irregularity. However, due to ambiguity in the evaluation of these criteria, usually designers ignore the control of these criteria altogether. This study tries to provide simple and easy to evaluate numerical criterion to detect vertical stiffness irregularity. Evaluation of the current codes criteria reveal that satisfaction of the code criteria provides different levels of safety against deformation localization for different stories and different structures. Then, it is shown that it is possible to evaluate a conservative estimate of drift for nonlinear analyses using the results of linear elastic analyses. Finally, to detect the possibility and extent of probable deformation localization in different stories due to vertical stiffness irregularity, a numerical criterion using the results of linear static analysis is proposed.
Assessment of Analytical Load and Dynamic Increase Factors for Progressive Collapse Analysis of Building Frames
Authors: Tsai Meng-Hao
Published: February 2012

Linear and nonlinear static procedures for evaluating the alternative load paths of building frames under column loss conditions have been refined in the latest Unified Facilities Criteria UFC 4-023-03 in 2009. One substantial modification in the 2009 version is the consideration of material nonlinearity for the load increase factor (LIF) and dynamic increase factor (DIF) in static analyses. In this study, analytical LIF and DIF expressions are compared with the empirical formulae recommended in the UFC guidelines. Static and dynamic analyses are carried out for eight moment-resisting frames subjected to column loss. The resulting LIFs and DIFs are used to evaluate the adequacy of the analytical expressions as compared to the empirical formulae. Accuracy of the analytical formulae in predicting the collapse resistance is also demonstrated. The study results indicate that the proposed analytical expressions may be an alternative in estimating the LIF and DIF for progressive collapse analysis.
In-Plane Bending of Laminated Glass Fin Strengthened through External Bonding
Authors: Shi Gang , Liu Zhao , Bai Yu , Shi Yongjiu , Wang Yuanqing
Published: February 2012

Laminated glass fins are often used in glass curtain wall system where they are subjected to in-plane bending. Due to a relatively low edge strength of glass, strengthening of the edge of glass fin becomes necessary. In-pane bending experiments were conducted on the unstrengthened laminated glass fins and the strengthened ones by means of glass plates or stainless steel strips. It was found that the load-carrying capacity was improved (25.6%) similarly for both strengthening approaches while strengthening at only the edges of glass fin appears to be more efficient. Parametric investigations based on the validated finite element models further indicated that such an improvement depends on the composite action between glass fin and strengthening components. It was demonstrated that the composite action was enhanced by increasing the length or deceasing the height of the glass fin, or by decreasing the width or height of the strengthening component. The results obtained are expected to provide valuable information for the design of all-glass curtain wall structures with variable geometries and the improvement of their load carrying capacity.
A Refined Model for Typhoon Wind Field Simulation in Boundary Layer
Authors: Huang W.F. , Xu Y.L.
Published: February 2012

The currently-used typhoon wind field models for wind resistance design of buildings and structures in typhoon regions often neglect the influence of temperature and assume that the central pressure difference does not vary with height above the ground. However, the observations made from field measurements and numerical simulations do not support this assumption. This paper thus presents a refined typhoon wind field model without this assumption and the decomposition method is then used to find the solution. The model is finally applied to Typhoon York. The wind speed and direction computed from the refined model are compared with those measured at the Waglan Island and the Di Wang Tower, and those predicted by the Meng model and the Shapiro model. The spatial distribution of wind speed in a horizontal plane is given through an isotach analysis and compared with the visual imagery of Typhoon York. Mean wind profiles at different distances from the typhoon center are also computed and compared with the field data and the power law profiles. The results demonstrate that the refined model gives more accurate wind speed, direction and profile than other models.
Comparison of Stochastic Responses of Asphaltic Concrete Core and Asphaltic Lining Dams with Clay Core Dams to Stationary and Nonstationary Excitation
Authors: Hacıefendioğlu Kemal , Soyluk Kurtuluş , Birinci Fahri
Published: February 2012

This paper presents the advantages of using asphalt in lining dams and in asphaltic concrete core dams when comparing with clay core dams. For this purpose, the linear and nonlinear stochastic responses of a clay core dam, an asphaltic lining dam and an asphaltic concrete core dam subjected to stationary and non-stationary excitation including spatially varying ground motion (SVEGM) effects are determined by finite element method. The nonlinear response is based on equivalent linear method, which considers the nonlinear variation of soil shear moduli and damping as a function of shear strain. The results are compared with those of the responses computed using linear response for uniform ground motion and SVEGM. The spatial variability of ground motion is taken into account with incoherence and wave passage effects. Stationary as well as non-stationary stochastic response analyses are performed for three types of dam. A time dependent frequency response function is used throughout the study for non-stationary responses. It is observed from the results that it can be possible to use of asphaltic lining dams and an asphaltic concrete core dams instead of clay core dams.
The dynamic measurement uncertainty evaluation on coal mine pump performance testing systems
Authors: Wang G. , Xie X. , Jiao S. , Zhang L. , Niu Q.
Published: February 2012

In view of applying the static measurement theory to evaluate the measurement uncertainty of a testing system, this paper develops a comprehensive coal mine pump performance testing system based on virtual instruments, and applies unascertained theory to evaluate the system's dynamic measurement uncertainty. Compared with the traditional measurement uncertainty of A kind and B kind, this method is without the limitation of the direct measurement, and the question condition and the evaluation better fit reality.
Versatile low-pressure plasma-enhanced process for synthesis of iron and iron-based magnetic nanopowders
Authors: Zelina P. , Jašek O. , Kudrle V. , David B. , Pizúrová N. , Pavliňák D. , Voráč Z. , Hemzal D.
Published: February 2012

Using microwave low-pressure discharge, we synthesised magnetic iron-oxide nanopowder from the iron pentacarbonyl precursor. We were able to vary the size and chemical composition (especially the ratio between various iron oxides) by careful control of the process parameters. The nanoparticulate product was analysed by X-ray diffraction (XRD) and Raman spectroscopy. However, the XRD cannot reliably distinguish between the size-broadened peaks of γ-Fe2O3 (maghemite) and Fe3O4 (magnetite) due to their nearly identical crystalline structure. Hence we used a chemical method to determine the presence of Fe(II) and Fe(III) ions in the nanopowder samples. The results agree with those from the Raman spectroscopy.
An investigation of structural composite laminates
Authors: Chowdhury M.
Published: February 2012

The following presentation is divided into two parts, A and B. The ultimate objective of this investigation is to compute the ‘extreme’ loading conditions that will cause failure of one or more of the constituent laminas in a laminate. The failure criterion used here is that of the maximum stress. The ‘extreme’ loading condition is computed by the application of conventional Linear Programming (LP) techniques. This aspect is discussed in Part B. However, in order to form the LP problem it was felt necessary to develop a suitable method of analysis of the laminate under most general loading conditions. Part A gives the aspects of this stand-alone version of a laminate analysis method using matrix notations. The analysis is based on simple Classical Laminate Theory (CLT). The outcomes of this part are the so-called stress and strain coefficient matrices.
Nonlinear Interactions of Multiple Linearly Unstable Thermoacoustic Modes
Authors: Moeck Jonas P. , Paschereit Christian Oliver
Published: February 2012

We investigate the dynamics of thermoacoustic systems with multiple linearly unstable modes. If a linear analysis reveals more than one mode with positive growth rate, nonlinear methods have to be used to determine the existence and stability of steady-state oscillations. One possible way to engage this problem is a first-order harmonic balance approach based on describing function representations for the flame response. In contrast to the case of a single unstable mode, the nonlinearity output to multiple sinusoidal components with different frequencies and amplitudes has to be known. Based on this approach, we present conditions for the existence and stability of single- or multi-mode steady-state oscillations. We apply this method to a thermoacoustic model system having two linearly unstable modes. By varying one of the system parameters, we find stable and unstable single-mode steady-states as well as unstable simultaneous oscillations. Associated with the stability of the single-mode limit cycles, we identify hysteresis in the oscillation type. Some related experimental observations are discussed.
Fluid Mechanics of Lean Blowout Precursors in Gas Turbine Combustors
Authors: Muruganandam T. M. , Seitzman J. M.
Published: February 2012

Understanding of lean blowout (LBO) phenomenon, along with the sensing and control strategies could enable the gas turbine combustor designers to design combustors with wider operability regimes. Sensing of precursor events (temporary extinction-reignition events) based on chemiluminescence emissions from the combustor, assessing the proximity to LBO and using that data for control of LBO has already been achieved. This work describes the fluid mechanic details of the precursor dynamics and the blowout process based on detailed analysis of near blowout flame behavior, using simultaneous chemiluminescence and droplet scatter observations. The droplet scatter method represents the regions of cold reactants and thus help track unburnt mixtures. During a precursor event, it was observed that the flow pattern changes significantly with a large region of unburnt mixture in the combustor, which subsequently vanishes when a double/single helical vortex structure brings back the hot products back to the inlet of the combustor. This helical pattern is shown to be the characteristic of the next stable mode of flame in the longer combustor, stabilized by double helical vortex breakdown (VBD) mode. It is proposed that random heat release fluctuations near blowout causes VBD based stabilization to shift VBD modes, causing the observed precursor dynamics in the combustor. A complete description of the evolution of flame near the blowout limit is presented. The description is consistent with all the earlier observations by the authors about precursor and blowout events.
RNA-Puzzles: A CASP-like evaluation of RNA three-dimensional structure prediction
Authors: Cruz José Almeida , Blanchet Marc-Frédérick , Boniecki Michal , Bujnicki Janusz M. , Chen Shi-Jie , Cao Song , Das Rhiju , Ding Feng , Dokholyan Nikolay V. , Flores Samuel Coulbourn , Huang Lili , Lavender Christopher A. , Lisi Véronique , Major François , Mikolajczak Katarzyna , Patel Dinshaw J. , Philips Anna , Puton Tomasz , Santalucia John , Sijenyi Fredrick , Hermann Thomas , Rother Kristian , Rother Magdalena , Serganov Alexander , Skorupski Marcin , Soltysinski Tomasz , Sripakdeevong Parin , Tuszynska Irina , Weeks Kevin M. , Waldsich Christina , Wildauer Michael , Leontis Neocles B. , Westhof Eric
Published: February 2012

We report the results of a first, collective, blind experiment in RNA three-dimensional (3D) structure prediction, encompassing three prediction puzzles. The goals are to assess the leading edge of RNA structure prediction techniques; compare existing methods and tools; and evaluate their relative strengths, weaknesses, and limitations in terms of sequence length and structural complexity. The results should give potential users insight into the suitability of available methods for different applications and facilitate efforts in the RNA structure prediction community in ongoing efforts to improve prediction tools. We also report the creation of an automated evaluation pipeline to facilitate the analysis of future RNA structure prediction exercises.
Nucleic Acid Detection Immunoassay for Prostate-Specific Antigen Based on Immuno-PCR Methodology
Authors: McDermed Jonathan E , Sanders Ron , Fait Stephen , Klem Robert E , Sarno Mark J , Adams Thomas H , Diamandis Eleftherios P
Published: February 2012

BACKGROUND

Serum prostate-specific antigen (PSA) concentrations after radical prostatectomy typically become undetectable with the use of current immunometric assay methods. Despite modern surgical techniques, 15%–30% of prostate cancer patients undergoing radical prostatectomy develop a biochemical recurrence during follow-up. Unfortunately, poor analytical sensitivity of standard PSA assays delays biochemical recurrence detection, and because of day-to-day assay imprecision ultrasensitive PSA assays cannot assess PSA kinetics. We developed an immuno-PCR assay for total PSA that has a limit of quantification >10 times lower than current ultrasensitive assays.

METHODS

The 2-site immunometric assay for total PSA employed 2 monoclonal antibodies, one conjugated to a double-stranded DNA label and the other bound to paramagnetic microparticles. After several washing steps, quantification cycles were determined and values were converted to PSA concentrations. We characterized analytical performance and compared accuracy with a commercially available total PSA assay.

RESULTS

The limit of quantification was 0.65 ng/L and the assay was linear in the range of 0.25–152.0 ng/L. Total imprecision estimates at PSA concentrations of 3.8, 24.1, and 69.1 ng/L were <15.2%, <9.4%, and <10.6%, respectively. Recovery of supplemented PSA ranged from 87.5% to 119.2% (mean 100.3%). Dilution recovery ranged from 96.4% to 115.3% (mean 102.3%). There was no high-dose hook effect up to 50 000 ng/L of PSA. Comparison with the commercial PSA assay showed a regression slope of 1.06 and a correlation coefficient of 0.996.

CONCLUSIONS

The analytical characteristics of the assay support the use of this assay for the accurate and precise measurement of serum PSA, even at sub–nanogram-per-liter concentrations.
Between Bitterness and Sweetness, When Bodies Say it All
Authors: Grillot Caroline
Published: February 2012

As emblems of otherness in a space devoted to commercial and human exchanges and dedicated to mercantilism, Vietnamese women who cross the border and now live in areas bordering China have quickly come to represent their country—in the eyes of Chinese people—as a figure of marginal femininity. Observed, dated, used but rarely understood in a linguistic and cultural sense, it is their strong, sensual, and docile bodies that are primarily considered. Contradictory and accommodating images emerge and then expand in the discourses, portraying these women as submissive spouses, tireless workers, prostitutes, manipulators, heartless pragmatists, devoted companions, and ambiguous merchants. This articles explores how, between perception and experience, these women's availability, in every sense of the term, makes them both attractive and suspicious, and how their alliances with Chinese men crystallizes the social atmosphere of a border city like Hekou.
Noninvasive Evaluation of Coronary Artery Bypass Grafts with 16-Slice Multidetector Computed Tomography
Authors: Sahiner Levent , Oto Ali , Aytemir Kudret , Hazirolan Tuncay , Karcaaltincaba Musturay , Akata Deniz
Published: February 2012

Background: The aim of this study was to investigate the diagnostic accuracy of 16-slice multislice, multidetector computed tomography (MDCT) angiography for the evaluation of grafts in patients with coronary artery bypass grafting (CABG).

Methods: Fifty-eight consecutive patients with CABG who underwent both MDCT and conventional invasive coronary angiography were included. The median time interval between the 2 procedures was 10 days (range, 1-32 days). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDCT for the detection of occluded grafts were calculated. The accuracy of MDCT angiography for detecting significant stenoses in patent grafts and the evaluability of proximal and distal anastomoses were also investigated.

Results: Optimal diagnostic images could not be obtained for only 3 (2%) of 153 grafts. Evaluation of the remaining 150 grafts revealed values for sensitivity, specificity, PPV, NPV, and diagnostic accuracy of the MDCT angiography procedure for the diagnosis of occluded grafts of 87%, 97%, 94%, 93%, and 92%, respectively. All of the proximal anastomoses were optimally visualized. In 4 (8%) of 50 patent arterial grafts, however, the distal anastomotic region could not be evaluated because of motion and surgical-clip artifacts. The accuracy of MDCT angiography for the detection of significant stenotic lesions was relatively low (the sensitivity, specificity, PPV, and NPV were 67%, 98%, 50%, and 99%, respectively). The number of significant lesions was insufficient to reach a reliable conclusion, however.

Conclusion: Our study showed that MDCT angiography with 16-slice systems has acceptable diagnostic performance for the evaluation of coronary artery bypass graft patency.
Transapical versus Conventional Aortic Valve Replacement�A Propensity-Matched Comparison
Authors: Holzhey David M. , Shi William , Rastan A. , Borger Michael A. , H�nsig Martin , Mohr Friedrich W.
Published: February 2012

Introduction: The goal of this study was to compare the short- and long-term outcomes after aortic valve (AV) surgery carried out via standard sternotomy/partial sternotomy versus transapical transcatheter AV implantation (taTAVI).

Patients and Methods: All 336 patients who underwent taTAVI between 2006 and 2010 were compared with 4533 patients who underwent conventional AV replacement (AVR) operations between 2001 and 2010. Using propensity score matching, we identified and consecutively compared 2 very similar groups of 167 patients each. The focus was on periprocedural complications and long-term survival.

Results: The 30-day mortality rate was 10.8% and 8.4% (P = .56) for the conventional AVR patients and the TAVI patients, respectively. The percentages of postoperative pacemaker implantations (15.0% versus 6.0%, P = .017) and cases of renal failure requiring dialysis (25.7% versus 12.6%, P = .004) were higher in the TAVI group. Kaplan-Meier curves diverged after half a year in favor of conventional surgery. The estimated 3-year survival rates were 53.5% � 5.7% (TAVI) and 66.7% � 0.2% (conventional AVR).

Conclusion: Our study shows that even with all the latest successes in catheter-based AV implantation, the conventional surgical approach is still a very good treatment option with excellent long-term results, even for older, high-risk patients.