bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of salmonid habitat growth potential through measurements of invertebrate food abundance and temperature
Authors: Weber Nicholas , Bouwes Nicolaas , Jordan Chris E.
Published: April 2014

Criteria used to characterize lotic salmonid habitat suitability are often based on correlations between physical habitat characteristics and salmonid abundance. Focusing on physical habitat features ignores other habitat components, such as an adequate food supply, that limit the amount of energy available for growth and survival. We tested the degree that food availability and temperature influence lotic salmonid consumption and growth rates and outline an approach for assessing habitat quality based on measurements of these features. We collected benthic and drifting invertebrate abundances, stream temperatures, and juvenile steelhead – rainbow trout (Onchorhynchus mykiss gairdneri) summer growth rates among nine stream segments in central Oregon. Stream temperatures and growth rates were used in bioenergetics model simulations to estimate O. mykiss consumption rates. The variation in O. mykiss consumption rates was explained by measurements of total drift biomass along a type II predator response curve (R2 = 0.71). This simplified foraging relationship between food abundance and consumption is then used to estimate the consumption component of the bioenergetics model to allow estimation of salmonid growth potential. Validation of the growth potential model produced reasonably accurate estimates of fish growth rates at reaches within the study area and precise but biased estimates in novel systems. While additional reach-level habitat information may be required to make the model more generalizable, the assessment of invertebrate food availability offers a simple yet powerful approach for describing the growth potential of stream habitat.
Examining the utility of fishery and survey data to detect prey removal effects on Steller sea lions (Eumetopias jubatus)
Authors: Conn Paul B. , Johnson Devin S. , Fritz Lowell W. , Fadely Brian S.
Published: April 2014

One focus of mitigation for Steller sea lion (Eumetopias jubatus) declines in Alaska has been to restrict commercial fishery activity around sea lion rookeries and haul-outs. However, a variety of statistical hypothesis tests have failed to relate sea lion population metrics to fish and fishing variables, prompting speculation that regulations may be unwarranted. In this study, we use simulation to show that standard hypothesis tests often have overstated power to detect a relationship between Steller sea lion vital rates and fish or fishing variables. The power and utility of hypothesis tests largely depend on choosing appropriate dependent and independent variables. In particular, pup counts were the most effective for diagnosing fecundity effects, and successive ratios of adult counts were the most effective for diagnosing survival effects. Fish relative abundance was the most effective independent variable, with other choices (e.g., fishery catch) often resulting in misleading inferences. We argue that Bayes factors are best suited for characterizing the relationship between fish abundance and Steller sea lion vital rates and that existing evidence does not preclude a strong relationship between sea lion fecundity and the availability of commercially harvested fish stocks.
Leptonic CP violation and leptogenesis
Authors: Petcov S. T.
Published: April 2014

The phenomenology of 3-neutrino mixing, the current status of our knowledge about the 3-neutrino mixing parameters, including the absolute neutrino mass scale, and of the Dirac and Majorana CP violation in the lepton sector, are reviewed. The problems of CP violation in neutrino oscillations and of determining the nature — Dirac or Majorana — of massive neutrinos, are discussed. The seesaw mechanism of neutrino mass generation and the related leptogenesis scenario of generation of the baryon asymmetry of the universe, are considered. The results showing that the CP violation necessary for the generation of the baryon asymmetry of the universe in leptogenesis can be due exclusively to the Dirac and/or Majorana CP-violating phase(s) in the neutrino mixing matrix U, are briefly reviewed.
RPV SUSY effects in $\tau^- \to e^-(\mu^-) K\bar{K}$ decays
Authors: Li Wenjun , Nie Xiao-Qin , Fan Ying-Ying , Lu Ming-Qiang , Guo Yu-Wei
Published: April 2014

In this paper, we investigate [Formula: see text] decays in the framework of the RPV SUSY model. We discuss the tree-level contribution of the sparticles [Formula: see text] and [Formula: see text] to these decay branching ratios. In the two channels, the [Formula: see text]-mediated channel is more sensitive to the parameter product [Formula: see text] than the [Formula: see text]-mediated channel to [Formula: see text]. And the parameter product [Formula: see text] is severely constrained to the order of [Formula: see text] by the experiment data with [Formula: see text], which is one order of magnitude more stringent than before. In the calculation of hadronic matrix elements, the resonant effects are large than those of nonresonant terms. Especially, the resonant contribution of scalar meson f(980) plays a dominate role in [Formula: see text]-mediated channel.
Two-loop part of the rational homotopy of spaces of long embeddings
Authors: Conant Jim , Costello Jean , Turchin Victor , Weed Patrick
Published: April 2014

Arone and Turchin defined graph-complexes computing the rational homotopy of the spaces of long embeddings. The graph-complexes split into a direct sum by the number of loops in graphs. In this paper, we compute the homology of its two-loop part.
Relational quadrilateralland II: The Quantum Theory
Authors: Anderson Edward , Kneller Sophie
Published: April 2014

We provide the quantum treatment of the relational quadrilateral. The underlying reduced configuration spaces are ℂℙ2 and the cone over this. We consider exact free and isotropic HO potential cases and perturbations about these. Moreover, our purely relational kinematical quantization is distinct from the usual one for ℂℙ2, which turns out to carry absolutist connotations instead. Thus, this paper is the first to note absolute-versus-relational motion distinctions at the kinematical rather than dynamical level. It is also an example of value to the discussion of kinematical quantization along the lines of Isham, 1984. The relational quadrilateral is the simplest RPM whose mathematics is not standard in atomic physics (the triangle and four particles on a line are both based on 𝕊2 and ℝ3 mathematics). It is far more typical of the general quantum relational N-a-gon than the previously studied case of the relational triangle. We consider useful integrals as regards perturbation theory and the peaking interpretation of quantum cosmology. We subsequently consider problem of time (PoT) applications of this: quantum Kuchař beables, the Machian version of the semiclassical approach and the timeless naïve Schrödinger interpretation. These go toward extending the combined Machian semiclassical-Histories-Timeless Approach of [Int. J. Mod. Phys. D23 (2014) 1450014] to the case of the quadrilateral, which will be treated in subsequent papers.
Energy conservation in high-pT nuclear reactions
Authors: Kopeliovich B. Z. , Nemchik J. , Potashnikova I. K. , Schmidt Iván
Published: April 2014

The Cronin effect, which is nuclear enhancement of high-pT hadron production in pA collisions was successfully predicted prior the measurements at RHIC and LHC. The restrictions imposed by energy conservation lead to spectacular effects. Energy deficit becomes an issue for hadron production in pA collisions at large xL and/or large xT toward the kinematic bounds xL, T = 1. It leads to a suppression, which has been indeed observed for hadrons produced at forward rapidities and large pT. Intensive energy dissipation via gluon radiation by a highly virtual parton produced with large pT, makes this process impossible to continue long. Color neutralization and creation of a colorless dipole must occur promptly. When this happens inside a hot medium created in AA collisions, attenuation of dipoles, rather than induced energy loss, becomes a dominant mechanism for suppression of high-pT hadrons.
AN INTERPOLATING ELEMENT-FREE GALERKIN METHOD FOR STEADY-STATE HEAT CONDUCTION PROBLEMS
Authors: REN HONGPING , WANG LIPING , ZHAO NA
Published: April 2014

In this paper, an interpolating element-free Galerkin (IEFG) method is presented for steady-state heat conduction problems with heat generation and spatially varying conductivity. The shape function in the moving least-squares (MLS) approximation does not satisfy the property of Kronecker delta function, so an interpolating moving least-squares (IMLS) method is discussed, then combining the shape function constructed by the IMLS method and Galerkin weak form of the two-dimensional steady-state heat conduction problems, the IEFG method for heat conduction problems is presented, and the corresponding formulae are obtained. The main advantage of this approach over the conventional meshless methods is that essential boundary conditions can be applied directly. Numerical results show that the IEFG method not only has high computational accuracy, but also enhances computational efficiency greatly.
CONTROLLABLE WRINKLING OF THIN FILMS ON PRE-STRETCHED ELASTOMERS INDUCED BY GRAVITY
Authors: WANG FANG , LI KAI , LIU KAI
Published: April 2014

We study wrinkling instability of a thin elastic film on a pre-stretched soft elastomer induced by the gravity of periodic array of the rods homogenously clamped on the surface of the film. By using linear perturbation analysis, we show that the periodic array of the rods can drive the wrinkling instability of the film when the gravitational force of the rods attains the threshold, and the film will wrinkle into stripes parallel to the tensile direction of the pre-stretched elastomer. Our calculation results give the stability criterion of the system, and the threshold of the gravitational force and the wavelength of the wrinkling patterns are obtained, which can be controlled by tuning the magnitude of the pre-stretch and properties of the thin film and the soft elastomer. These results may provide a regulating strategy for generating precise surface patterns in similar rod structures.
Sensitivity of Near-Surface Temperature Forecasts to Soil Properties over a Sparsely Vegetated Dryland Region
Authors: Massey Jeffrey D. , Steenburgh W. James , Hoch Sebastian W. , Knievel Jason C.
Published: April 2014

Weather Research and Forecasting Model forecasts over the Great Salt Lake Desert erroneously underpredict nocturnal cooling over the sparsely vegetated silt loam soil area of Dugway Proving Ground in northern Utah, with a mean positive bias error in temperature at 2 m AGL of 3.4°C in the early morning [1200 UTC (0500 LST)]. Positive early-morning bias errors also exist in nearby sandy loam soil areas. These biases are related to the improper initialization of soil moisture and parameterization of soil thermal conductivity in silt loam and sandy loam soils. Forecasts of 2-m temperature can be improved by initializing with observed soil moisture and by replacing Johansen's 1975 parameterization of soil thermal conductivity in the Noah land surface model with that proposed by McCumber and Pielke in 1981 for silt loam and sandy loam soils. Case studies illustrate that this change can dramatically reduce nighttime warm biases in 2-m temperature over silt loam and sandy loam soils, with the greatest improvement during periods of low soil moisture. Predicted ground heat flux, soil thermal conductivity, near-surface radiative fluxes, and low-level thermal profiles also more closely match observations. Similar results are anticipated in other dryland regions with analogous soil types, sparse vegetation, and low soil moisture.
Observations of the Variation in Aerosol and Cloud Microphysics along the 20°S Transect on 13 November 2008 during VOCALS-REx
Authors: Cui Zhiqiang , Gadian Alan , Blyth Alan , Crosier Jonathan , Crawford Ian
Published: April 2014

Observations are presented of the structure of the marine boundary layer (MBL) in the southeastern Pacific made with the U.K. BAe 146 aircraft on 13 November 2008 as it flew at a variety of altitudes along 20°S between the coast of Chile and a buoy 950 km offshore during the Variability of American Monsoon Systems (VAMOS) Ocean–Cloud–Atmosphere–Land Study (VOCALS) Regional Experiment (REx). The purpose of the study is to determine the variations along the 20°S transect in the clouds and boundary layer on this particular day as compared to the typical structure determined from the composite studies. The aircraft flew in three regions on this day: relatively continuous thick stratocumulus clouds, open cells, and closed cells. Results show three particular features. First, the results of the cloud microphysics are consistent with the typical behavior showing a decrease in aerosol particles by a factor of 3–4, and a decrease in cloud droplet number concentration westward from the coast from about 200 to 100 cm−3 or less with a corresponding increase in the concentration of drizzle drops with a maximum in open cells. Sulfate was dominant in the aerosol mass. Second, there was evidence of decoupling of the marine boundary layer that coincided with a change in the cloud type from stratiform to convective. The case differs from the average found in VOCALS in that the decoupling is not consistent with the deepening–warming idea. Precipitation is thought to possibly be the cause instead, suggesting that aerosol might play a controlling role in the cloud–boundary layer structure. Finally, cold pools were observed in the MBL from the dropsonde data.
On the Choice of Average Solar Zenith Angle
Authors: Cronin Timothy W.
Published: April 2014

Idealized climate modeling studies often choose to neglect spatiotemporal variations in solar radiation, but doing so comes with an important decision about how to average solar radiation in space and time. Since both clear-sky and cloud albedo are increasing functions of the solar zenith angle, one can choose an absorption-weighted zenith angle that reproduces the spatial- or time-mean absorbed solar radiation. Calculations are performed for a pure scattering atmosphere and with a more detailed radiative transfer model and show that the absorption-weighted zenith angle is usually between the daytime-weighted and insolation-weighted zenith angles but much closer to the insolation-weighted zenith angle in most cases, especially if clouds are responsible for much of the shortwave reflection. Use of daytime-average zenith angle may lead to a high bias in planetary albedo of approximately 3%, equivalent to a deficit in shortwave absorption of approximately 10 W m−2 in the global energy budget (comparable to the radiative forcing of a roughly sixfold change in CO2 concentration). Other studies that have used general circulation models with spatially constant insolation have underestimated the global-mean zenith angle, with a consequent low bias in planetary albedo of approximately 2%–6% or a surplus in shortwave absorption of approximately 7–20 W m−2 in the global energy budget.
Incorporating an Urban Irrigation Module into the Noah Land Surface Model Coupled with an Urban Canopy Model
Authors: Vahmani Pouya , Hogue Terri S.
Published: April 2014

The current research examines the influence of irrigation on urban hydrological cycles through the development of an irrigation scheme within the Noah land surface model (LSM)–Single Layer Urban Canopy Model (SLUCM) system. The model is run at a 30-m resolution for a 2-yr period over a 49 km2 urban domain in the Los Angeles metropolitan area. A sensitivity analysis indicates significant sensitivity relative to both the amount and timing of irrigation on diurnal and monthly energy budgets, hydrological fluxes, and state variables. Monthly residential water use data and three estimates of outdoor water consumption are used to calibrate the developed irrigation scheme. Model performance is evaluated using a previously developed MODIS–Landsat evapotranspiration (ET) and Landsat land surface temperature (LST) products as well as hourly ET observations through the California Irrigation Management Information System (CIMIS). Results show that the Noah LSM–SLUCM realistically simulates the diurnal and seasonal variations of ET when the irrigation module is incorporated. However, without irrigation, the model produces large biases in ET simulations. The ET errors for the nonirrigation simulations are −56 and −90 mm month−1 for July 2003 and 2004, respectively, while these values decline to −6 and −11 mm month−1 over the same 2 months when the proposed irrigation scheme is adopted. Results show that the irrigation-induced increase in latent heat flux leads to a decrease in LST of about 2°C in urban parks. The developed modeling framework can be utilized for a number of applications, ranging from outdoor water use estimation to climate change impact assessments.
A Real-Time Algorithm for Merging Radar QPEs with Rain Gauge Observations and Orographic Precipitation Climatology
Authors: Zhang Jian , Qi Youcun , Langston Carrie , Kaney Brian , Howard Kenneth
Published: April 2014

High-resolution, accurate quantitative precipitation estimation (QPE) is critical for monitoring and prediction of flash floods and is one of the most important drivers for hydrological forecasts. Rain gauges provide a direct measure of precipitation at a point, which is generally more accurate than remotely sensed observations from radar and satellite. However, high-quality, accurate precipitation gauges are expensive to maintain, and their distributions are too sparse to capture gradients of convective precipitation that may produce flash floods. Weather radars provide precipitation observations with significantly higher resolutions than rain gauge networks, although the radar reflectivity is an indirect measure of precipitation and radar-derived QPEs are subject to errors in reflectivity–rain rate (Z–R) relationships. Further, radar observations are prone to blockages in complex terrain, which often result in a poor sampling of orographically enhanced precipitation. The current study aims at a synergistic approach to QPE by combining radar, rain gauge, and an orographic precipitation climatology. In the merged QPE, radar data depict high-resolution spatial distributions of the precipitation and rain gauges provide accurate precipitation measurements that correct potential biases in the radar QPE. The climatology provides a high-resolution background of the spatial precipitation distribution in the complex terrain where radar coverage is limited or nonexistent. The merging algorithm was tested on heavy precipitation events in different areas of the United States and provided a superior QPE to the individual components. The new QPE algorithm is fully automated and can be easily implemented in an operational system.
How Does the Choice of Distributed Meteorological Data Affect Hydrologic Model Calibration and Streamflow Simulations?
Authors: Elsner Marketa M. , Gangopadhyay Subhrendu , Pruitt Tom , Brekke Levi D. , Mizukami Naoki , Clark Martyn P.
Published: April 2014

Spatially distributed historical meteorological forcings (temperature and precipitation) are commonly incorporated into modeling efforts for long-term natural resources planning. For water management decisions, it is critical to understand the uncertainty associated with the different choices made in hydrologic impact assessments (choice of hydrologic model, choice of forcing dataset, calibration strategy, etc.). This paper evaluates differences among four commonly used historical meteorological datasets and their impacts on streamflow simulations produced using the Variable Infiltration Capacity (VIC) model. The four meteorological datasets examined here have substantial differences, particularly in minimum and maximum temperatures in high-elevation regions such as the Rocky Mountains. The temperature differences among meteorological forcing datasets are generally larger than the differences between calibration and validation periods. Of the four meteorological forcing datasets considered, there are substantial differences in calibrated model parameters and simulations of the water balance. However, no single dataset is superior to the others with respect to VIC simulations of streamflow. Also, optimal calibration parameter values vary across case study watersheds and select meteorological datasets, suggesting that there is enough flexibility in the calibration parameters to compensate for the effects of using select meteorological datasets. Evaluation of runoff sensitivity to changes in climate indicates that the choice of meteorological dataset may be as important in characterizing changes in runoff as climate change, supporting consideration of multiple sources of uncertainty in long-term planning studies.
Analysis of Catania Flash Flood Case Study by Using Combined Microwave and Infrared Technique
Authors: Di Paola Francesco , Ricciardelli Elisabetta , Cimini Domenico , Romano Filomena , Viggiano Mariassunta , Cuomo Vincenzo
Published: April 2014

In this paper, the analysis of an extreme convective event atypical for the winter season, which occurred on 21 February 2013 on the east coast of Sicily and caused a flash flood over Catania, is presented. In just 1 h, more than 50 mm of precipitation was recorded, but it was not forecast by numerical weather prediction (NWP) models and, consequently, no severe weather warnings were sent to the population. The case study proposed is first examined with respect to the synoptic situation and then analyzed by means of two algorithms based on satellite observations: the Cloud Mask Coupling of Statistical and Physical Methods (MACSP) and the Precipitation Evolving Technique (PET), developed at the National Research Council of Italy. Both of the algorithms show their ability in the near-real-time monitoring of convective cell formation and their rapid evolution. As quantitative precipitation forecasts by NWP could fail, especially for atypical convective events like in Catania, tools like MACSP and PET shall be adopted by civil protection centers to monitor the real-time evolution of deep convection events in aid to the severe weather warning service.
Equilibration of the Antarctic Circumpolar Current by Standing Meanders
Authors: Thompson Andrew F. , Naveira Garabato Alberto C.
Published: April 2014

The insensitivity of the Antarctic Circumpolar Current (ACC)’s prominent isopycnal slope to changes in wind stress is thought to stem from the action of mesoscale eddies that counterbalance the wind-driven Ekman overturning—a framework verified in zonally symmetric circumpolar flows. Substantial zonal variations in eddy characteristics suggest that local dynamics may modify this balance along the path of the ACC. Analysis of an eddy-resolving ocean GCM shows that the ACC can be broken into broad regions of weak eddy activity, where surface winds steepen isopycnals, and a small number of standing meanders, across which the isopycnals relax. Meanders are coincident with sites of (i) strong eddy-induced modification of the mean flow and its vertical structure as measured by the divergence of the Eliassen–Palm flux and (ii) enhancement of deep eddy kinetic energy by up to two orders of magnitude over surrounding regions. Within meanders, the vorticity budget shows a balance between the advection of relative vorticity and horizontal divergence, providing a mechanism for the generation of strong vertical velocities and rapid changes in stratification. Temporal fluctuations in these diagnostics are correlated with variability in both the Eliassen–Palm flux and bottom speed, implying a link to dissipative processes at the ocean floor. At larger scales, bottom pressure torque is spatially correlated with the barotropic advection of planetary vorticity, which links to variations in meander structure. From these results, it is proposed that the “flexing” of standing meanders provides an alternative mechanism for reducing the sensitivity of the ACC’s baroclinicity to changes in forcing, separate from an ACC-wide change in transient eddy characteristics.
Utility-Scale Wind Turbine Wake Characterization Using Nacelle-Based Long-Range Scanning Lidar
Authors: Aitken Matthew L. , Lundquist Julie K.
Published: April 2014

To facilitate the optimization of turbine spacing at modern wind farms, computational simulations of wake effects must be validated through comparison with full-scale field measurements of wakes from utility-scale turbines operating in the real atmosphere. Scanning remote sensors are particularly well suited for this objective, as they can sample wind fields over large areas at high temporal and spatial resolutions. Although ground-based systems are useful, the vantage point from the nacelle is favorable in that scans can more consistently transect the central part of the wake. To the best of the authors’ knowledge, the work described here represents the first analysis in the published literature of a utility-scale wind turbine wake using nacelle-based long-range scanning lidar.

The results presented are of a field experiment conducted in the fall of 2011 at a wind farm in the western United States, quantifying wake attributes such as the velocity deficit, centerline location, and wake width. Notable findings include a high average velocity deficit, decreasing from 60% at a downwind distance x of 1.8 rotor diameters (D) to 40% at x = 6D, resulting from a low average wind speed and therefore a high average turbine thrust coefficient. Moreover, the wake width was measured to expand from 1.5D at x = 1.8D to 2.5D at x = 6D. Both the wake growth rate and the amplitude of wake meandering were observed to be greater for high ambient turbulence intensity and daytime conditions as compared to low turbulence and nocturnal conditions.
VORTEX2 Observations of a Low-Level Mesocyclone with Multiple Internal Rear-Flank Downdraft Momentum Surges in the 18 May 2010 Dumas, Texas, Supercell*
Authors: Skinner Patrick S. , Weiss Christopher C. , French Michael M. , Bluestein Howard B. , Markowski Paul M. , Richardson Yvette P.
Published: April 2014

Observations collected in the second Verification of the Origins of Rotation in Tornadoes Experiment during a 15-min period of a supercell occurring on 18 May 2010 near Dumas, Texas, are presented. The primary data collection platforms include two Ka-band mobile Doppler radars, which collected a near-surface, short-baseline dual-Doppler dataset within the rear-flank outflow of the Dumas supercell; an X-band, phased-array mobile Doppler radar, which collected volumetric single-Doppler data with high temporal resolution; and in situ thermodynamic and wind observations of a six-probe mobile mesonet.

Rapid evolution of the Dumas supercell was observed, including the development and decay of a low-level mesocyclone and four internal rear-flank downdraft (RFD) momentum surges. Intensification and upward growth of the low-level mesocyclone were observed during periods when the midlevel mesocyclone was minimally displaced from the low-level circulation, suggesting an upward-directed perturbation pressure gradient force aided in the intensification of low-level rotation. The final three internal RFD momentum surges evolved in a manner consistent with the expected behavior of a dynamically forced occlusion downdraft, developing at the periphery of the low-level mesocyclone during periods when values of low-level cyclonic azimuthal wind shear exceeded values higher aloft. Failure of the low-level mesocyclone to acquire significant vertical depth suggests that dynamic forcing above internal RFD momentum surge gust fronts was insufficient to lift the negatively buoyant air parcels comprising the RFD surges to significant heights. As a result, vertical acceleration and the stretching of vertical vorticity in surge parcels were limited, which likely contributed to tornadogenesis failure.
A Physically Based Precipitation–Nonprecipitation Radar Echo Classifier Using Polarimetric and Environmental Data in a Real-Time National System
Authors: Tang Lin , Zhang Jian , Langston Carrie , Krause John , Howard Kenneth , Lakshmanan Valliappa
Published: April 2014

Polarimetric radar observations provide information regarding the shape and size of scatterers in the atmosphere, which help users to differentiate between precipitation and nonprecipitation radar echoes. Identifying and removing nonprecipitation echoes in radar reflectivity fields is one critical step in radar-based quantitative precipitation estimation. An automated algorithm based on reflectivity, correlation coefficient, and temperature data is developed to perform reflectivity data quality control through a set of physically based rules. The algorithm was tested with a large number of real data cases across different geographical regions and seasons and showed a high accuracy (Heidke skill score of 0.83) in segregating precipitation and nonprecipitation echoes. The algorithm was compared with two other operational and experimental reflectivity quality control methodologies and showed a more effective removal of nonprecipitation echoes and a higher computational efficiency. The current methodology also demonstrated a satisfactory performance in a real-time national multiradar and multisensor system.
Telling Transitions
Authors: Taylor Carol A.
Published: April 2014

Based in an analysis of a writing workshop which explored students’ transition to higher education, this article puts to work theorizations of space by Massey, materiality by Barad, narrative by Cavarero, and ethics by Arendt to propose an innovative conceptualization of collaborative writing practices. The article proposes an understanding of the space of collaborative writing as a multiplicity of relations, negotiations, and practices; it considers what is to be gained from considering collaborative writing in relation to posthumanist concerns about the mattering of matter; and it illuminates how collaborative writing, when understood as the emergence of narratable selves, is a profoundly ethical practice.
Long-Term Follow-up of a Novel Anastomotic Device in a Canine Model
Authors: Park Adrian , Lee Tommy H. , Kavic Stephen M.
Published: April 2014

Construction of intestinal anastomosis is a fundamental general surgery skill. New constraints in creating safe, effective anastomoses are faced, however, even as minimally invasive surgery techniques continue to gain popular and scientific support. We present our experience in developing and testing a novel anastomotic device (AD) constructed of a shape memory metal, with long-term follow-up in a canine model. This device has the potential for both laparoscopic and endoscopic delivery because of its unique design and adaptable deployment system. Eight canines had gastroduodenal and jejunojejunal anastomoses formed with the AD: the gastroduodenal anastomosis by transecting the stomach immediately distal to the pylorus and forming a side-to-side functional end-to-end anastomosis and the jejunojejunal anastomosis similarly following transection in the mid-jejunum. Four animals were survived for 6 months, and 4 for 12 months. At the study’s end, the animals were euthanized and the anastomotic sites harvested for both gross and microscopic pathology. Two animals developed postoperative complications: one a mechanical bowel obstruction from bedding ingestion that required laparotomy, and one an ileus that conservative management resolved. All animals survived to their endpoints, displaying normal growth and development. All jejunojejunal anastomoses had AD passage and microscopic evidence of complete healing. Meanwhile, none of the gastroduodenal devices passed, with microscopy demonstrating incomplete mucosalization. This AD is highly effective in forming jejunojejunal anastomoses. Gastroduodenal anastomoses, while highly functional, retained the device without complete healing. Future studies using a more human-like animal model and an anastomotic technique avoiding the thick pylorus muscle should yield better results.
Short-time heat treatment of press hardened steel for laser assisted clinching
Authors: Reich M. , Osten J. , Milkereit B. , Kalich J. , Füssel U. , Kessler O.
Published: April 2014

Clinching of high strength steels is currently difficult due to their relative low ductility. Hence a new method has been developed to clinch these steel grades. This could be achieved by heating the sheets locally at the joint by a laser during the clinching process. The short-time tempering behaviour of the press hardened steel 22MnB5 has been investigated by dilatometry respectively calorimetry experiments. Different stages of the tempering process have been identified depending on heating rates up to 1000 K s−1. Characteristic tempering reactions were shifted to higher temperatures with increasing heating rate. Based on these results, suitable short-time heat treatment parameters have been selected and transferred to the clinching process. Thereby the press hardened steel 22MnB5 has been successfully clinched with laser assistance for the very first time. The laser assisted clinched joint has been characterised by metallographic analysis and hardness testing. It could be shown, that in the clinching joint only a slight strength loss occurs due to the introduced laser heat.
Use of partial least squares for identifying the effect of through process variables on some of the magnetic properties (permeability) of grain oriented electrical steel
Authors: Evans M. , McMahon J. , Robinson F.
Published: April 2014

As there are a large number of process variables involved in manufacturing grain oriented electrical steel, partial least squares (PLS) was used to study the influence of these process parameters on some magnetic properties and in particular on permeability. It was found that a model containing just two PLS components provided an adequate best fit to the process data with the most important variables being some of the alloying elements contained within the delivery of steel from the IJmuiden plant and the chemistry changes at the decarburisation line. Also of importance was the temperature in the early zones in the decarburising furnace and the latter zones in the annealing pickling line furnace.
Inhibition of autophagy enhances the cytotoxic effect of PA-MSHA in breast cancer
Authors: Xu Wen-Huan , Liu Zhe-Bin , Hou Yi-Feng , Hong Qi , Hu Da-Li , Shao Zhi-Ming
Published: April 2014

Background

PA-MSHA, a genetically engineered Pseudomonas aeruginosa (PA) strain, is currently under investigation as a new anti-cancer drug. It can induce cell cycle arrest and apoptosis in different human cancer cells, including hormone receptor negative breast cancer cells. However, the underlying mechanism of tumor lethality mediated by PA-MSHA remains to be fully investigated.

Methods

The effect of PA-MSHA on human hormone receptor negative breast cancer cells was analyzed by morphological measurement, western blot, cell proliferation assay and mouse xenograft model.

Results

PA-MSHA was found to induce endoplasmic reticulum (ER) stress in breast cancer cell lines through the IRE1 signaling pathway. Inhibiting autophagy potentiated the cytotoxic effect of PA-MSHA while treating breast cancer cell lines. In mouse xenograft model, PA-MSHA produced more pronounced tumor suppression in mice inoculated with IRE1 gene knockdown. MDA-MB-231HM cells.

Conclusions

These findings demonstrated inhibiting autophagy together with PA-MSHA might be a promising therapeutic strategy in treating hormone receptor negative breast cancer cells.
Surgicel™ application in intracranial hemorrhage surgery contributed to giant-cell granuloma in a patient with hypertension: case report and review of the literature
Authors: Lin Bowen , Yang Hongfa , Cui Mengzhao , Li Ye , Yu Jinlu
Published: April 2014

Background

Surgicel™ is an oxidized cellulose preparation that is widely applied in neurosurgery due to its hemostatic effect and good tissue compatibility. Tumor-like lesions induced by Surgicel® application in cerebral surgery have been rarely reported, especially for intracranial hemorrhage debridement surgery in patients with hypertension.

Case presentation

This case report describes a rare case in which Surgicel™ application led to a foreign body reaction, contributing to the development of an intracranial giant-cell granuloma. A 49-year-old female hypertensive patient was diagnosed with intracranial hemorrhage. She was treated with debridement surgery that employed Surgicel™ application. Although a satisfactory hemostatic effect was achieved, the patient was diagnosed with epilepsy 6 months later. Subsequent magnetic resonance imaging revealed an intracranial space-occupying lesion. After undergoing en bloc resection of the lesion, the patient was diagnosed with a Surgicel™-related intracranial giant-cell granuloma by histopathology.

Conclusions

Application of Surgicel™ during intracranial hemorrhage debridement surgery may be associated with a risk of granuloma development due to formation of a tumor-like space-occupying lesion in the surgery bed. Even a low risk of tumor development implies a need for caution when applying Surgicel™, especially when solely used to achieve a hemostatic effect.
Concave-convex local binary features for automatic target recognition in infrared imagery
Authors: Sun Junding , Fan Guoliang , Yu Liangjiang , Wu Xiaosheng
Published: April 2014

This paper presents a novel feature extraction algorithm based on the local binary features for automatic target recognition (ATR) in infrared imagery. Since the inception of the local binary pattern (LBP) and local ternary pattern (LTP) features, many extensions have been proposed to improve their robustness and performance in a variety of applications. However, most attentions were paid to improve local feature extraction with little consideration on the incorporation of global or regional information. In this work, we propose a new concave-convex partition (CCP) strategy to improve LBP and LTP by dividing local features into two distinct groups, i.e., concave and convex, according to the contrast between local and global intensities. Then two separate histograms built from the two categories are concatenated together to form a new LBP/LTP code that is expected to better reflect both global and local information. Experimental results on standard texture images demonstrate the improved discriminability of the proposed features and those on infrared imagery further show that the proposed features can achieve competitive ATR results compared with state-of-the-art methods.
Understanding factors associated with the translation of cardiovascular research: a multinational case study approach
Authors: Wooding Steven , Hanney Stephen R , Pollitt Alexandra , Grant Jonathan , Buxton Martin J
Published: April 2014

Background

Funders of health research increasingly seek to understand how best to allocate resources in order to achieve maximum value from their funding. We built an international consortium and developed a multinational case study approach to assess benefits arising from health research. We used that to facilitate analysis of factors in the production of research that might be associated with translating research findings into wider impacts, and the complexities involved.

Methods

We built on the Payback Framework and expanded its application through conducting co-ordinated case studies on the payback from cardiovascular and stroke research in Australia, Canada and the United Kingdom. We selected a stratified random sample of projects from leading medical research funders. We devised a series of innovative steps to: minimize the effect of researcher bias; rate the level of impacts identified in the case studies; and interrogate case study narratives to identify factors that correlated with achieving high or low levels of impact.

Results

Twenty-nine detailed case studies produced many and diverse impacts. Over the 15 to 20 years examined, basic biomedical research has a greater impact than clinical research in terms of academic impacts such as knowledge production and research capacity building. Clinical research has greater levels of wider impact on health policies, practice, and generating health gains. There was no correlation between knowledge production and wider impacts. We identified various factors associated with high impact. Interaction between researchers and practitioners and the public is associated with achieving high academic impact and translation into wider impacts, as is basic research conducted with a clinical focus. Strategic thinking by clinical researchers, in terms of thinking through pathways by which research could potentially be translated into practice, is associated with high wider impact. Finally, we identified the complexity of factors behind research translation that can arise in a single case.

Conclusions

We can systematically assess research impacts and use the findings to promote translation. Research funders can justify funding research of diverse types, but they should not assume academic impacts are proxies for wider impacts. They should encourage researchers to consider pathways towards impact and engage potential research users in research processes.
Kinetic and equilibrium study of the chromatographic separation of glycine and ammonium
Authors: Jiang Lihua , Liu Huiyuan , Qiu Yongjun , Wang Yaosong , Chen Chaoqin , Wang Qifan , Zhao Liming
Published: April 2014

Background

Glycine is extensively applied in the field of food, medicine, agrochemistry, etc. It is usually commercially produced by the chemosynthesis method, which generates large amounts of by-product ammonium chloride.

Methods

In this paper, the separation of glycine and ammonium chloride was performed with chromatographic column, and deionized water as eluent. The adsorption equilibrium constant K of glycine and ammonium chloride was evaluated by frontal analysis. Based on the equilibrium-dispersive model and a linear driving force of chromatography, the overall mass transfer coefficient k

m
, axial dispersion coefficient D

L
, and bed voidage ε

t
of the column were obtained by moment analysis.

Results

At 50°C, the equilibrium constants measured were found to be 0.72 and 0.19 for glycine and ammonium chloride, respectively. At 60°C, the equilibrium constants increased to 0.80 and 0.21 for glycine and ammonium chloride, respectively. The value of axial dispersion coefficient D

L
of glycine had the same order of magnitude with ammonium chloride and was about two times larger than that of ammonium chloride. Their k

m
at 50°C and 60°C were 1.30 and 0.77 and 2.41 and 0.84 min−1 for glycine and ammonium chloride, respectively.

Conclusions

The obtained parameters used to simulate the elution curve and the simulation and experimental results matched well, which showed that the parameters obtained were effective. The results make foundation for further study on large-scale separation of glycine from ammonium chloride by SMB chromatography.
Learning About New Technologies Through Social Networks: Experimental Evidence on Nontraditional Stoves in Bangladesh
Authors: Miller Grant , Mobarak A. Mushfiq
Published: April 2014

There are few marketing studies of social learning about new technologies in low-income countries. This paper examines how learning through opinion leaders and social networks influences demand for nontraditional cookstoves—a technology with important health and environmental consequences for developing country populations. We conduct marketing interventions in rural Bangladesh to assess how stove adoption decisions respond to (a) learning the adoption choices of locally identified “opinion leaders” and (b) learning about stove attributes and performance through social networks. We find that households generally draw negative inferences about stoves through social learning and that social learning is more important for stoves with less evident benefits. In an institutional environment where consumers are distrustful of new products and brands, consumers appear to rely on their networks more to learn about negative product attributes. Overall, our findings imply that external information and marketing campaigns can induce initial adoption and experiential learning about unfamiliar technologies, but sustained use ultimately requires that new technologies match local preferences.
Valuing Customer Portfolios with Endogenous Mass and Direct Marketing Interventions Using a Stochastic Dynamic Programming Decomposition
Authors: Esteban-Bravo Mercedes , Vidal-Sanz Jose M. , Yildirim Gökhan
Published: April 2014

The customer relationship management allocation in marketing budgets is potentially misleading when it uses individual customer lifetime value estimations from historical data. Planned marketing interventions would change the purchasing behavior of different customers, and history-based decisions would thus be suboptimal. To cope with this inherent endogeneity, we model the optimal allocation of the marketing mix by accounting simultaneously for mass interventions and direct marketing interventions for each customer. This is a large stochastic dynamic problem that, in general, is computationally rather intractable as a result of the “curse of dimensionality.” We present an algorithm to derive the optimal marketing policies (how the firm should allocate its marketing resources) and the expected present value of those decisions, which maximize the long-term profitability of firms. This allows the firm to value customers/segments and helps the firm to target those that maximize long-term profitability given the optimal marketing resources allocation. We apply the proposed approach in the context of a kitchen appliance manufacturer. The results identify the most effective marketing policies and the endogenous customer values. It is in this context that we also dynamically identify the most profitable customer and the short- and long-term effects of marketing activities on each customer.
When Does the Devil Make Work? An Empirical Study of the Impact of Workload on Worker Productivity
Authors: Tan Tom Fangyun , Netessine Serguei
Published: April 2014

We analyze a large, detailed operational data set from a restaurant chain to shed new light on how workload (defined as the number of tables or diners that a server simultaneously handles) affects servers' performance (measured as sales and meal duration). We use an exogenous shock—the implementation of labor scheduling software—and time-lagged instrumental variables to disentangle the endogeneity between demand and supply in this setting. We show that servers strive to maximize sales and speed efforts simultaneously, depending on the relative values of sales and speed. As a result, we find that, when the overall workload is small, servers expend more and more sales efforts with the increase in workload at a cost of slower service speed. However, above a certain workload threshold, servers start to reduce their sales efforts and work more promptly with the further rise in workload. In the focal restaurant chain, we find that this saturation point is currently not reached and, counterintuitively, the chain can reduce the staffing level and achieve both significantly higher sales (an estimated 3% increase) and lower labor costs (an estimated 17% decrease).

This paper was accepted by Noah Gans, special issue on business analytics.
Skilled players cooperate less in multi-player games
Authors: Chesney Thomas , Chuah Swee-Hoon , Hoffmann Robert , Hui Wendy , Larner Jeremy
Published: April 2014

A naturalistic public good experiment is used to examine whether better players cooperate more or less than others. ‘Better’ is measured by subjects’ accuracy in a team-based shooting game, and cooperation is measured by introducing a public good decision into the game. A data set of 92 subjects was created and results show that better players cooperate significantly less than others. Economic theory is used to explain the result.