bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palatoglossus coupling in selective upper airway stimulation
Authors: Heiser Clemens , Edenharter Günther , Bas Murat , Wirth Markus , Hofauer Benedikt 
Published: January 2017

Objectives/HypothesisSelective upper airway stimulation (sUAS) of the hypoglossal nerve is a useful therapy to treat patients with obstructive sleep apnea. Is it known that multiple obstructions can be solved by this stimulation technique, even at the retropalatal region. The aim of this study was to verify the palatoglossus coupling at the soft palate during stimulation.Study DesignSingle‐center, prospective clinical trail.MethodsTwenty patients who received an sUAS implant from April 2015 to April 2016 were included. A drug‐induced sedated endoscopy (DISE) was performed before surgery. Six to 12 months after activation of the system, patients' tongue motions were recorded, an awake transnasal endoscopy was performed with stimulation turned on, and a DISE with stimulation off and on was done.ResultsPatients with a bilateral protrusion of the tongue base showed a significantly increased opening at the retropalatal level compared to ipsilateral protrusions. Furthermore, patients with a clear activation of the geniohyoid muscle showed a better reduction in apnea‐hypopnea index.ConclusionsA bilateral protrusion of the tongue base during sUAS seems to be accompanied with a better opening of the soft palate. This effect can be explained by the palatoglossal coupling, due to its linkage of the muscles within the soft palate to those of the lateral tongue body.Level of Evidence4 Laryngoscope, 127:E378–E383, 2017
Sediment resuspension mechanisms and their contributions to high‐turbidity events in a large lake
Authors: Valipour Reza , Boegman Leon , Bouffard Damien , Rao Yerubandi R. 
Published: January 2017

AbstractHigh‐resolution field data, collected during April to October of 2008–2009, were analyzed to investigate the quantitative contribution of sediment resuspension to high‐turbidity events in central Lake Erie. Resuspension events were distinguished within high‐turbidity events according to turbidity, fluorescence and acoustic backscatter timeseries, as well as satellite images. We observed 16 high‐turbidity events, causing a total duration of ∼20 d (out of 344 d) with elevated nearbed turbidity (> 10 NTU). Of these events, 64% were correlated with algal biomass, with the remaining 18%, 5%, and 4% being attributed to sediment resuspension by surface waves, storm‐generated currents and enhanced nearbed turbulence induced by high‐frequency internal waves, respectively. This is the first time that resuspension by enhanced nearbed turbulence from high‐frequency linear internal wave degeneration has been observed in a large lake. Resuspension was parameterized as a function of the instantaneous critical bottom velocity, bottom shear stress and the Shields parameter. From the in situ measurements, we suggest an extended Shields diagram for silty bed material that can be used to predict resuspension in other aquatic systems with similar sediment composition (∼20% cohesive sediment).
SIPCO2: A simple, inexpensive surface water pCO2 sensor
Authors: Hunt Christopher W. , Snyder Lisle , Salisbury Joseph E. , Vandemark Douglas , McDowell William H. 
Published: January 2017

AbstractEfforts to estimate air‐water carbon dioxide (CO2) exchange on regional or global scales are constrained by a lack of direct, continuous surface water CO2 observations. Sensor technology for the in situ measurement of the partial pressure of carbon dioxide (pCO2) has progressed, but still poses limitations including expense and biofouling concerns. We describe a simple, inexpensive, in situ pCO2 method (SIPCO2) in which a non‐dispersive infrared (NDIR) detector is paired with an air pump in an enclosed housing to produce air‐sea equilibration. We first evaluated this approach in a laboratory setting, then in an estuarine‐coastal ocean laboratory for several months to continuously monitor aquatic pCO2. An accepted, accurate NDIR‐based CO2 measurement technique was employed alongside SIPCO2 to provide an assessment of sensor performance. SIPCO2 allows for low‐cost, relatively accurate measurements of pCO2 (mean difference of −5 ± 5 μatm from validation system after laboratory calibration) without reagents or membranes, and can be assembled and operated with a minimal amount of technical skill. While not suitable for some exacting applications, this SIPCO2 approach could rapidly and effectively increase the number of quality CO2 observations in a range of aquatic environments. We also provide detailed instructions for the assembly of SIPCO2 from commercially available components.
Isopropanol precipitation method for collecting fish environmental DNA
Authors: Doi Hideyuki , Uchii Kimiko , Matsuhashi Saeko , Takahara Teruhiko , Yamanaka Hiroki , Minamoto Toshifumi 
Published: January 2017

AbstractThe environmental DNA (eDNA) method has been used to estimate the distributions of aquatic species, and both ethanol precipitation and filtration‐based methods are commonly employed to capture eDNA from sampled water. Although filtration‐based methods can capture more eDNA than that by ethanol precipitation, by processing larger volumes of water (e.g., 1 L vs. 15 mL), ethanol precipitation can immediately preserve eDNA on site and ease downstream processing, which are especially advantageous for eDNA studies conducted with limited resources, such as electric equipment, labor, and time. However, the ethanol precipitation method is limited by small volume of water that can be processed (i.e., 15 mL in a reaction volume of 50 mL). As an alternative, isopropanol could potentially be used to increase the volume of sample water processed, since lower volumes of isopropanol are required for precipitation. Therefore, in the present study, we compared the copy numbers of carp eDNA captured using isopropanol and ethanol precipitation in both mesocosm and field experiments. In both cases, we found that isopropanol precipitation recovered double the amount of eDNA recovered by ethanol precipitation, when the reaction volumes were equal. Therefore, isopropanol precipitation is a superior option for eDNA capture when surveys are conducted under resource‐limited conditions.
Snowfall rate estimation using C‐band polarimetric radars
Authors: Hassan Diar , Taylor Peter A. , Isaac George A. 
Published: January 2017

ABSTRACT:Radar quantitative precipitation estimation plays an important role in weather forecasting, nowcasting and hydrological models. This study evaluates the Sekhon and Srivastava (1970) snow water equivalent (SWE) algorithm currently implemented by the Canadian Radar Network of Environment and Climate Change Canada, suggests an improved algorithm and also evaluates the ability of polarimetric radars in estimating SWE. The radar data were collected from the dual polarimetric King City radar (CWKR) near Toronto, Ontario, and the Doppler Holyrood radar (CWTP) in Newfoundland. SWE data were collected at Oakville, Ontario, at Pearson International Airport (CYYZ), Toronto, Ontario, and at Mount Pearl, Newfoundland. The ground observations show that the polarimetric variables could be used to infer a few of the microphysical processes during snowfall. It is suggested that the co‐polar correlation co‐efficient (ρhv) could be sensitive to the size ranges of different snow habits. Also, higher differential reflectivity (Zdr) values were measured with large aggregates. The results show a severe underestimation of SWE rates by the Sekhon and Srivastava algorithm. One hour accumulations from each site were used to develop SWE(ZeH) and SWE(ZeH, ZDR) algorithms (ZeH and ZDR are the reflectivity factor and differential reflectivity, respectively). Similarly, algorithms were developed using SWE at 10 min intervals from CYYZ and Mount Pearl but these algorithms appeared to overestimate SWE. The hourly SWE accumulations from the three sites were combined to produce an additional SWE(ZeH) algorithm which showed better statistical results. A modest difference was found between the conventional and polarimetric algorithms for estimating snowfall amounts (SWE).
Placental dysfunction is associated with altered microRNA expression in pregnant women with low folate status
Authors: Baker Bernadette C. , Mackie Fiona L. , Lean Samantha C. , Greenwood Susan L. , Heazell Alexander E. P. , Forbes Karen , Jones Rebecca L. 
Published: January 2017

ScopeLow maternal folate status during pregnancy increases the risk of delivering small for gestational age (SGA) infants, but the mechanistic link between maternal folate status, SGA, and placental dysfunction is unknown. microRNAs (miRNAs) are altered in pregnancy pathologies and by folate in other systems. We hypothesized that low maternal folate status causes placental dysfunction, mediated by altered miRNA expression.Methods and resultsA prospective observational study recruited pregnant adolescents and assessed third trimester folate status and placental function. miRNA array, QPCR, and bioinformatics identified placental miRNAs and target genes. Low maternal folate status is associated with higher incidence of SGA infants (28% versus 13%, p < 0.05) and placental dysfunction, including elevated trophoblast proliferation and apoptosis (p < 0.001), reduced amino acid transport (p < 0.01), and altered placental hormones (pregnancy‐associated plasma protein A, progesterone, and human placental lactogen). miR‐222‐3p, miR‐141‐3p, and miR‐34b‐5p were upregulated by low folate status (p < 0.05). Bioinformatics predicted a gene network regulating cell turnover. Quantitative PCR demonstrated that key genes in this network (zinc finger E‐box binding homeobox 2, v‐myc myelocytomatosis viral oncogene homolog (avian), and cyclin‐dependent kinase 6) were reduced (p < 0.05) in placentas with low maternal folate status.ConclusionThis study supports that placental dysfunction contributes to impaired fetal growth in women with low folate status and suggests altered placental expression of folate‐sensitive miRNAs and target genes as a mechanistic link.
Inclusion of a variable RBE into proton and photon plan comparison for various fractionation schedules in prostate radiation therapy
Authors: Ödén Jakob , Eriksson Kjell , Toma‐Dasu Iuliana 
Published: January 2017

PurposeA constant relative biological effectiveness (RBE) of 1.1 is currently used in proton radiation therapy to account for the increased biological effectiveness compared to photon therapy. However, there is increasing evidence that proton RBE vary with the linear energy transfer (LET), the dose per fraction, and the type of the tissue. Therefore, this study aims to evaluate the impact of disregarding variations in RBE when comparing proton and photon dose plans for prostate treatments for various fractionation schedules using published RBE models and several α/β assumptions.MethodsPhoton and proton dose plans were created for three generic prostate cancer cases. Three BED3Gy equivalent schedules were studied, 78, 57.2, and 42.8 Gy in 39, 15, and 7 fractions, respectively. The proton plans were optimized assuming a constant RBE of 1.1. By using the Monte Carlo calculated dose‐averaged LET (LETd) distribution and assuming α/β values on voxel level, three variable RBE models were applied to the proton dose plans. The impact of the variable RBE was studied in the plan comparison, which was based on the dose distribution, DVHs, and normal tissue complication probabilities (NTCP) for the rectum. Subsequently, the physical proton dose was reoptimized for each proton plan based on the LETd distribution, to achieve a homogeneous RBE‐weighted target dose when applying a specific RBE model and still fulfill the clinical goals for the rectum and bladder.ResultsAll the photon and proton plans assuming RBE = 1.1 met the clinical goals with similar target coverage. The proton plans fulfilled the robustness criteria in terms of range and setup uncertainty. Applying the variable RBE models generally resulted in higher target doses and rectum NTCP compared to the photon plans. The increase was most pronounced for the fractionation dose of 2 Gy(RBE), whereas it was of less magnitude and more dependent on model and α/β assumption for the hypofractionated schedules. The reoptimized proton plans proved to be robust and showed similar target coverage and doses to the organs at risk as the proton plans optimized with a constant RBE.ConclusionsModel predicted RBE values may differ substantially from 1.1. This is most pronounced for fractionation doses of around 2 Gy(RBE) with higher doses to the target and the OARs, whereas the effect seems to be of less importance for the hypofractionated schedules. This could result in misleading conclusions when comparing proton plans to photon plans. By accounting for a variable RBE in the optimization process, robust and clinically acceptable dose plans, with the potential of lowering rectal NTCP, may be generated by reoptimizing the physical dose. However, the direction and magnitude of the changes in the physical proton dose to the prostate are dependent on RBE model and α/β assumptions and should therefore be used conservatively.
A local artificial boundary for transient seepage problems with unsteady boundary conditions in unbounded domains
Authors: Song Er‐xiang , Luo Shuang 
Published: January 2017

AbstractNumerical analysis of transient seepage in unbounded domains with unsteady boundary conditions requires a more sophisticated artificial boundary approach to deal with the infinite character of the domain. To that end, a local artificial boundary is established by simplifying a global artificial boundary. The global artificial boundary conditions (ABCs) at the truncated boundary are derived from analytical solutions for one‐dimensional axisymmetric diffusion problems. By applying Laplace transforms and introducing some specially defined auxiliary variables, the global ABCs are simplified to local ABCs to significantly enhance the computational efficiency. The proposed local ABCs are implemented in a finite element computer program so that the solutions to various seepage problems can be calculated. The proposed approach is first verified by the computation of a one‐dimensional radial flow problem and then tentatively applied to more general two‐dimensional cylindrical problems and planar problems. The solutions obtained using the local ABCs are compared with those obtained using a large element mesh and using a previously proposed local boundary. This comparison demonstrates the satisfactory performance and obvious superiority of the newly established boundary to the other local boundary. Copyright © 2017 John Wiley & Sons, Ltd.
The Impact of Frictions in Routine Execution on Economies of Scope
Authors: Brahm Francisco , Tarzijan Jorge , Singer Marcos 
Published: January 2017

Research summary: Based on a detailed database of a beverages producer‐distributor that expanded its product variety by leveraging its logistic network, we show that product diversification generates economies of scope and also higher operational costs. The result is an inverted‐U relationship between variety and productivity: When the firm offers few additional categories, productivity grows, but as the number of categories rises, the costs of executing the operational routines increase rapidly and productivity falls. The negative effect on productivity increases if the added product category is more dissimilar to previous ones, and decreases with learning from operational experience. Our results highlight how frictions at the operational level can limit the benefits of diversification, even in the absence of other sources of diseconomies, such as increased coordination needs.Managerial summary: One of the prevalent reasons for companies to expand to adjacent product lines is attaining economies of scope. However, such growth strategy also generates operational frictions, even if the day‐to‐day routines do not appear to change at all. Product diversity is disruptive for routine execution, as it requires coordination and exception handling, and may ultimately overcome any efficiency obtained from growth. We estimate the relevance of such operational friction using data from a beverages distribution network. When product variety is low, additional categories do generate efficiency, but after reaching a given threshold, friction prevails. We find that operational friction increases when products are more dissimilar, but is attenuated when workers learn from their own and other's experience. Copyright © 2017 John Wiley & Sons, Ltd.
Hydrodynamic Effects in Soft‐matter Self‐assembly: The Case of J‐Aggregates of Amphiphilic Porphyrins
Authors: Ribo Josep M. , El‐Hachemi Zoubir , Arteaga Oriol , Canillas Adolf , Crusats Joaquim 
Published: January 2017

AbstractChiral J‐aggregates of achiral amphiphilic porphyrins (4‐sulfonatophenyl and aryl meso‐substituted porphyrins) show several effects under the hydrodynamic forces of common stirring. These effects can be classified as pure mechanic (e. g. elasticity, plasticity and breaking of the self‐assembly non‐covalent bonding) and chemically selective as detected in the formation/growth of the nanoparticles. Diastereoselective, enantioselective and, depending on the sign of chiral shear forces, even enantiospecific selections have been described. Some types of these effects have been reported in other type of J‐aggregates. Reversible and irreversible structural effects have been studied by atomic force imaging. The determination of the optical polarization properties (linear and circular) of their solutions is best done using Mueller matrix polarimetry methods.
Efficient handover measurement technique for small‐cell networks using a virtual cell synchronization signal
Authors: Pec Rothna , Park Chang Hwan , Cho Yong Soo 
Published: January 2017

AbstractA small‐cell network (SCN) constructed by splitting a macro‐cell into numerous small cells using an active antenna array system is studied. A synchronization signal appropriate for the SCN, virtually generated by an eNodeB with 3D beamforming, is proposed for efficient handover in SCNs. The virtual cell synchronization signal (VCSS) carries a macro‐cell ID (MCID) and virtual‐cell ID (VCID) in a hierarchical manner, allowing us to distinguish between an intra‐cell handover (virtual cell handover within a cell without changing the serving eNodeB) and inter‐cell handover (virtual cell handovers across cells while changing the serving eNodeB) in SCNs. Using the signal metrics obtained by the VCSS, an efficient handover measurement technique is proposed which can significantly reduce the processing time and overhead by distinguishing between the intra‐cell/inter‐cell handovers. The performance of the proposed technique is evaluated by simulating two different deployment scenarios of LTE‐based SCN with 3D beamforming. Copyright © 2017 John Wiley & Sons, Ltd.
Generalized energy‐based fragmentation approach for modeling condensed phase systems
Authors: Fang Tao , Li Yunzhi , Li Shuhua 
Published: January 2017

We have extended the generalized energy‐based fragmentation (GEBF) method to condensed phase systems with periodic boundary condition (PBC). The so‐called PBC‐GEBF method provides an alternative way of calculating electronic structures of condensed phase systems, whose accuracy is comparable to standard periodic electronic structure methods for some types of condensed phase systems such as molecular crystals and ionic liquid crystals. Within the PBC‐GEBF approach, the unit cell energy (or properties) of a condensed phase system can be evaluated as a linear combination of ground‐state energies (or corresponding properties) of a series of electrostatically embedded subsystems, which can be routinely calculated with existing molecular quantum chemistry packages. With the PBC‐GEBF approach, one can routinely perform ab initio calculations at post‐Hartree–Fock levels, including Møller–Plesset perturbation theory (MP2) or coupled cluster singles and doubles, on certain types of condensed phase systems, in which periodic post‐Hartree–Fock methods are not available or not feasible computationally. This review will offer an overview of the methodology and implementation of the PBC‐GEBF method and its applications in predicting the structures, lattice energies, and vibrational spectra of a wide range of molecular and ionic liquid crystals. Our results show that the PBC‐GEBF approach at post‐Hartree–Fock theory level can generally provide highly accurate descriptions on the structure and properties of crystals under study. For example, the vibrational spectra of the crystalline BH3NH3 predicted by the PBC‐GEBF approach at the MP2 level are in better agreement with the experimentally observed spectra, than those based on density functional theory calculations. WIREs Comput Mol Sci 2017, 7:e1297. doi: 10.1002/wcms.1297This article is categorized under:

Structure and Mechanism > Molecular Structures
Hypercoordinate iodine(III) promoted reactions and catalysis: an update on current mechanistic understanding
Authors: Sreenithya A. , Surya K. , Sunoj Raghavan B. 
Published: January 2017

Mild and environment friendly hypercoordinate iodine compounds exhibit promising reactivities resembling that of transition metal catalysts. Hypercoordinate iodine reagents or catalysts are increasingly been employed in contemporary organic synthesis. However, mechanistic insights on such reactions continue to remain rather limited. Recent advances in the mechanistic understanding on a selected set of reactions involving hypercoordinate iodine form the main theme of this review. An overview of bonding, reactivity, and mechanistic insights on iodine(III) reactions such as α‐functionalization of carbonyl compounds, alkynylation, amination, CH functionalization, phenol dearomatization, and trifluoromethylation have been described. In keeping with the current practices in mechanistic studies, we have maintained an interdisciplinary flavor in this compilation by providing a balanced view of computational and experimental understanding on the burgeoning domain of hypercoordinate iodine mediated reactions and catalysis. WIREs Comput Mol Sci 2017, 7:e1299. doi: 10.1002/wcms.1299This article is categorized under:

Structure and Mechanism > Reaction Mechanisms and Catalysis
Optimal smoothing length scale for actuator line models of wind turbine blades based on Gaussian body force distribution
Authors: Martínez‐Tossas L. A. , Churchfield M. J. , Meneveau C. 
Published: January 2017

AbstractThe actuator line model (ALM) is a commonly used method to represent lifting surfaces such as wind turbine blades within large‐eddy simulations (LES). In the ALM, the lift and drag forces are replaced by an imposed body force that is typically smoothed over several grid points using a Gaussian kernel with some prescribed smoothing width ε. To date, the choice of ε has most often been based on numerical considerations related to the grid spacing used in LES. However, especially for finely resolved LES with grid spacings on the order of or smaller than the chord length of the blade, the best choice of ε is not known. In this work, a theoretical approach is followed to determine the most suitable value of ε, based on an analytical solution to the linearized inviscid flow response to a Gaussian force. We find that the optimal smoothing width εopt is on the order of 14%‐25% of the chord length of the blade, and the center of force is located at about 13%‐26% downstream of the leading edge of the blade for the cases considered. These optimal values do not depend on angle of attack and depend only weakly on the type of lifting surface. It is then shown that an even more realistic velocity field can be induced by a 2‐D elliptical Gaussian lift‐force kernel. Some results are also provided regarding drag force representation. Copyright © 2017 John Wiley & Sons, Ltd.