bluuebunny/crossref_metadata_2025_split huggingface dataset:
Season-Dependent Forecast Skill of the Leading Forced Atmospheric Circulation Pattern over the North Pacific and North American Region*
Authors: Jia XiaoJing , Lin Hai , Lee June-Yi , Wang Bin 
Published: April 2012

Abstract
Multimodel ensemble (MME) seasonal forecasts are analyzed to evaluate numerical model performance in predicting the leading forced atmospheric circulation pattern over the extratropical Northern Hemisphere (NH). Results show that the time evolution of the leading tropical Pacific sea surface temperature (SST)-coupled atmospheric pattern (MCA1), which is obtained by applying a maximum covariance analysis (MCA) between 500-hPa geopotential height (Z500) in the extratropical NH and SST in the tropical Pacific Ocean, can be predicted with a significant skill in March–May (MAM), June–August (JJA), and December–February (DJF) one month ahead. However, most models perform poorly in capturing the time variation of MCA1 in September–November (SON) with 1 August initial condition. Two possible reasons for the models’ low skill in SON are identified. First, the models have the most pronounced errors in the mean state of SST and precipitation along the central equatorial Pacific. Because of the link between the divergent circulation forced by tropical heating and the midlatitude atmospheric circulation, errors in the mean state of tropical SST and precipitation may lead to a degradation of midlatitude forecast skill. Second, examination of the potential predictability of the atmosphere, estimated by the ratio of the total variance to the variance of the model forecasts due to internal dynamics, shows that the atmospheric potential predictability over the North Pacific–North American (NPNA) region is the lowest in SON compared to the other three seasons. The low ratio in SON is due to a low variance associated with external forcing and a high variance related to atmospheric internal processes over this area.
Changing the Climate Sensitivity of an Atmospheric General Circulation Model through Cloud Radiative Adjustment
Authors: Sokolov Andrei P. , Monier Erwan 
Published: April 2012

Abstract
Conducting probabilistic climate projections with a particular climate model requires the ability to vary the model’s characteristics, such as its climate sensitivity. In this study, the authors implement and validate a method to change the climate sensitivity of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model, version 3 (CAM3), through cloud radiative adjustment. Results show that the cloud radiative adjustment method does not lead to physically unrealistic changes in the model’s response to an external forcing, such as doubling CO2 concentrations or increasing sulfate aerosol concentrations. Furthermore, this method has some advantages compared to the traditional perturbed physics approach. In particular, the cloud radiative adjustment method can produce any value of climate sensitivity within the wide range of uncertainty based on the observed twentieth century climate change. As a consequence, this method allows Monte Carlo–type probabilistic climate forecasts to be conducted where values of uncertain parameters not only cover the whole uncertainty range, but cover it homogeneously. Unlike the perturbed physics approach that can produce several versions of a model with the same climate sensitivity but with very different regional patterns of change, the cloud radiative adjustment method can only produce one version of the model with a specific climate sensitivity. As such, a limitation of this method is that it cannot cover the full uncertainty in regional patterns of climate change.
Warm Season Response over North America to a Shutdown of the Atlantic Meridional Overturning Circulation and CO2 Increases
Authors: Pu Bing , Vizy Edward K. , Cook Kerry H. 
Published: April 2012

Abstract
Paleo-proxy and modeling evidence suggest that a shutdown of the Atlantic meridional overturning circulation (AMOC) would decrease North Atlantic Ocean sea surface temperatures and have far-reaching climate impacts. The authors use a regional climate model to examine the warm season response over North America to a hypothetical late-twenty-first-century shutdown of the AMOC with increased atmospheric CO2. In the future simulation, precipitation decreases over the western and central United States by up to 40% and over eastern Mexico by up to 50%. Over the eastern United States rainfall generally increases except during July. Variations in the moisture convergence associated with large-scale circulation changes dominate the rainfall variations, while evaporation plays a critical role over the northeastern United States in spring and the north-central United States in summer. During April–June the westward extension of the North Atlantic subtropical high enhances southwesterly moisture fluxes from the Gulf of Mexico into the eastern and south-central United States. Increases in low-level moisture content reduce the stability of the atmosphere. Enhanced southerly winds promote convergence over the eastern United States through the Sverdrup vorticity balance and precipitation increases. In July–August anomalous anticyclonic moisture fluxes associated with an anomalous high over the Gulf of Mexico and eastern Pacific decrease the moisture supply into the United States and Mexico. Over the central United States decreases in evaporation support decreases in low-level moisture content and increases in atmospheric stability. Over the eastern United States the Sverdrup balance weakens in summer and anomalous moisture convergence is mainly located over the East Coast.
Daily, Global, High-Resolution SST and Sea Ice Reanalysis for 1985–2007 Using the OSTIA System
Authors: Roberts-Jones Jonah , Fiedler Emma Kathleen , Martin Matthew James 
Published: April 2012

Abstract
A sea surface temperature (SST) and sea ice reanalysis has been produced at the Met Office based on the Operational SST and Sea Ice Analysis (OSTIA) system. The OSTIA reanalysis produces daily, high-resolution, global foundation SST and sea ice concentration fields from 1 January 1985 to 31 December 2007. The SST reanalysis uses reprocessed satellite and in situ observations that are assimilated using a multiscale optimal-interpolation-type scheme similar to that used in the near-real-time OSTIA system. Validation of the SST analysis using assimilated in situ observation-minus-background statistics shows that the accuracy of the analysis increases throughout the reanalysis period; the global root-mean-square difference is approximately 0.50 K by 2007. This approach to validation is supported in the recent period by results from comparisons with independent near-surface Argo data against which a global standard deviation error of 0.55 K was calculated. Assessment of the OSTIA reanalysis at high latitudes demonstrates that the SST and sea ice fields are more consistent with one another in the Southern Hemisphere than in the Northern Hemisphere. Comparison of the sea ice extents to those in a similar reanalysis shows OSTIA to have larger extents in the Northern Hemisphere, and the Southern Hemisphere extents are similar. The OSTIA reanalysis SSTs are shown to be regionally comparable with similar reanalyses, with the largest differences occurring at high latitudes in the summer hemisphere. Differences are observed around the ice edge and in regions with high SST gradients. The OSTIA reanalysis provides a valuable high-resolution addition to the satellite period SST data record that makes use of the (Advanced) Along-Track Scanning Radiometer [(A)ATSR] multimission data.
Influence of Advective Accelerations on Estuarine Exchange at a Chesapeake Bay Tributary
Authors: Basdurak Nuvit B. , Valle-Levinson Arnoldo 
Published: April 2012

Abstract
The influence of nonlinear advection on estuarine exchange flow was investigated with observations at the transition between the James River and Chesapeake Bay, Hampton Roads, Virginia. Data were collected under different tidal forcing, wind forcing, and river discharge in 2004 and 2005. The relative contribution of nonlinear advective terms to the along-channel momentum balance had the same order of magnitude as pressure gradient and friction, verifying recent analytical and numerical model results. Both the magnitude and the spatial distribution of nonlinear advection showed fortnightly variability. Nonlinear advection was more influential on along-channel flow at spring tides than at neap tides because of increased tidal velocities, in a cross-sectionally averaged sense. The flow structures induced by each nonlinear advective process were investigated for the first time with observations. The lateral advection term υuy was found to enhance laterally sheared exchange acting along with Coriolis forcing at spring tides and opposing it at neap tides. Vertical advection wuz showed similar spatial distribution as υuy at spring tides but was vertically sheared (landward at middepth and seaward in the rest of the water column) at neaps. Longitudinal advection uux augmented landward flow in the channel.
Influence of Low-Level Thermodynamic Structure on the Downdraft Properties of Simulated Supercells
Authors: Naylor Jason , Askelson Mark A. , Gilmore Matthew S. 
Published: April 2012

Abstract
Idealized simulations using the Weather Research and Forecasting Model (WRF) were performed to examine the role of capping inversions on the near-surface thermodynamic structure of outflow from simulated supercells. Two simulations were performed: one with the traditional noncapped Weisman and Klemp (WK) analytic sounding and the second with a WK sounding modified to contain a capping inversion. Both sounding environments favor splitting storms and a right-moving supercell by 90 min into the simulation. These two supercell simulations evolve in a qualitatively similar fashion, with both storms exhibiting large, quasi-steady updrafts, hook-shaped appendages in the precipitation mixing ratio field, and prominent localized downdrafts.
Results show that the supercell simulated in the capped environment has a surface cold pool with larger values of pseudoequivalent potential temperature (θep) than the cold pool of the supercell produced in the noncapped simulation. Parcels in the surface cold pool of the supercell produced in the capped sounding simulation have a lower origin height than those in the surface cold pool of the supercell produced in the noncapped simulation for all times. Although θep values in the surface cold pool are primarily associated with the origin height of downdraft parcels and the environmental θep at that level, it is shown that nonconservation of θep primarily associated with hydrometeor melting can decrease θep values of downdraft parcels as they descend by several degrees.
Controlling the Computational Modes of the Arbitrarily Structured C Grid
Authors: Weller Hilary 
Published: April 2012

Abstract
The arbitrarily structured C grid, Thuburn–Ringler–Skamarock–Klemp (TRiSK), is being used in the Model for Prediction Across Scales (MPAS) and is being considered by the Met Office for their next dynamical core. However, the hexagonal C grid supports a branch of spurious Rossby modes, which lead to erroneous grid-scale oscillations of potential vorticity (PV). It is shown how these modes can be harmlessly controlled by using upwind-biased interpolation schemes for PV. A number of existing advection schemes for PV are tested, including that used in MPAS, and none are found to give adequate results for all grids and all cases. Therefore a new scheme is proposed; continuous, linear-upwind stabilized transport (CLUST), a blend between centered and linear-upwind with the blend dependent on the flow direction with respect to the cell edge.
A diagnostic of grid-scale oscillations is proposed that gives further discrimination between schemes than using potential enstrophy alone. Indeed, some schemes are found to destroy potential enstrophy while grid-scale oscillations grow.
CLUST performs well on hexagonal-icosahedral grids and unrotated skipped latitude–longitude grids of the sphere for various shallow-water test cases. Despite the computational modes, the hexagonal icosahedral grid performs well since these modes are easy and harmless to filter. As a result, TRiSK appears to perform better than a spectral shallow-water model.
The distinct category of healthcare associated bloodstream infections
Authors: Lenz Ryan , Leal Jenine R , Church Deirdre L , Gregson Daniel B , Ross Terry , Laupland Kevin B 
Published: April 2012

Abstract

Background
Bloodstream infections (BSI) have been traditionally classified as either community acquired (CA) or hospital acquired (HA) in origin. However, a third category of healthcare-associated (HCA) community onset disease has been increasingly recognized. The objective of this study was to compare and contrast characteristics of HCA-BSI with CA-BSI and HA-BSI.

Methods
All first episodes of BSI occurring among adults admitted to hospitals in a large health region in Canada during 2000-2007 were identified from regional databases. Cases were classified using a series of validated algorithms into one of HA-BSI, HCA-BSI, or CA-BSI and compared on a number of epidemiologic, microbiologic, and outcome characteristics.

Results
A total of 7,712 patients were included; 2,132 (28%) had HA-BSI, 2,492 (32%) HCA-BSI, and 3,088 (40%) had CA-BSI. Patients with CA-BSI were significantly younger and less likely to have co-morbid medical illnesses than patients with HCA-BSI or HA-BSI (p < 0.001). The proportion of cases in males was higher for HA-BSI (60%; p < 0.001 vs. others) as compared to HCA-BSI or CA-BSI (52% and 54%; p = 0.13). The proportion of cases that had a poly-microbial etiology was significantly lower for CA-BSI (5.5%; p < 0.001) compared to both HA and HCA (8.6 vs. 8.3%). The median length of stay following BSI diagnosis 15 days for HA, 9 days for HCA, and 8 days for CA (p < 0.001). Overall the most common species causing bloodstream infection were Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. The distribution and relative rank of importance of these species varied according to classification of acquisition. Twenty eight day all cause case-fatality rates were 26%, 19%, and 10% for HA-BSI, HCA-BSI, and CA-BSI, respectively (p < 0.001).

Conclusion
Healthcare-associated community onset infections are distinctly different from CA and HA infections based on a number of epidemiologic, microbiologic, and outcome characteristics. This study adds further support for the classification of community onset BSI into separate CA and HCA categories.
Hybrid cells derived from breast epithelial cell/breast cancer cell fusion events show a differential RAF-AKT crosstalk
Authors: Özel Cem , Seidel Jeanette , Meyer-Staeckling Sönke , Brandt Burkhard H , Niggemann Bernd , Zänker Kurt S , Dittmar Thomas 
Published: April 2012

Abstract

Background
The biological phenomenon of cell fusion has been linked to several characteristics of tumour progression, including an enhanced metastatogenic capacity and an enhanced drug resistance of hybrid cells. We demonstrated recently that M13SV1-EGFP-Neo breast epithelial cells exhibiting stem cell characteristics spontaneously fused with MDA-MB-435-Hyg breast cancer cells, thereby giving rise to stable M13MDA435 hybrid cells, which are characterised by a unique gene expression profile and migratory behaviour. Here we investigated the involvement of the PLC-β/γ1, PI3K/AKT and RAS-RAF-ERK signal transduction cascades in the EGF and SDF-1α induced migration of two M13MDA435 hybrid cell clones in comparison to their parental cells.

Results
Analysis of the migratory behaviour by using the three-dimensional collagen matrix migration assay showed that M13SV1-EGFP-Neo cells as well as M13MDA435 hybrid cells, but not the breast cancer cell line, responded to EGF stimulation with an increased locomotory activity. By contrast, SDF-1α solely stimulated the migration of M13SV1-EGFP-Neo cells, whereas the migratory activity of the other cell lines was blocked. Analysis of signal transduction cascades revealed a putative differential RAF-AKT crosstalk in M13MDA435-1 and -3 hybrid cell clones. The PI3K inhibitor Ly294002 effectively blocked the EGF induced migration of M13MDA435-3 hybrid cells, whereas the EGF induced locomotion of M13MDA435-1 hybrid cells was markedly increased. Analysis of RAF-1 S259 phosphorylation, being a major mediator of the negative regulation of RAF-1 by AKT, showed decreased pRAF-1 S259 levels in LY294002 treated M13MDA435-1 hybrid cells. By contrast, pRAF-1 S259 levels remained unaltered in the other cell lines. Inhibition of PI3K/AKT signalling by Ly294002 relieves the AKT mediated phosphorylation of RAF-1, thereby restoring MAPK signalling.

Conclusions
Here we show that hybrid cells could evolve exhibiting a differential active RAF-AKT crosstalk. Because PI3K/AKT signalling has been chosen as a target for anti-cancer therapies our data might point to a possible severe side effect of AKT targeted cancer therapies. Inhibition of PI3K/AKT signalling in RAF-AKT crosstalk positive cancer (hybrid) cells could result in a progression of these cells. Thus, not only the receptor (activation) status, but also the activation of signal transduction molecules should be analysed thoroughly prior to therapy.
Papillae reconstruction: clinical considerations
Authors: Palacci Patrick 
Published: April 2012

Implant restorations in the anterior maxilla are challenging, especially when treating patients with a high lip line and a lack of available tissue. These patients will exhibit large and unsightly dark embrasures reminiscent of severe gingival recession. The action of augmenting or regenerating soft tissue is more difficult to perform in the coronal direction than in other directions. Unfortunately, there is usually a need to replace lost tissue in the coronal dimension.Today’s dental implantology is not only focused on function but also aesthetics. Papilla reconstruction or preservation is a key factor for a successful aesthetic outcome.
An overview of the All-on-4™ implant philosophy
Authors: Maló Paulo , de Araújo Nobre Miguel , Lopes Armando 
Published: April 2012

The All-on-4™ implant approach for rehabilitation of edentulous jaws was developed at the Maló Clinic in the 1990s. Based on a concept of supporting a complete edentulous rehabilitation with four implants in immediate function, it was possible to resolve clinical situations that otherwise would need more complex/more expensive procedures.The concept underwent continuous development from standard to extra-maxillary approaches, and its clinical documentation proved that it can be considered a viable treatment option for rehabilitating edentulous jaws. This article features the presentation of the concept, the inclusion/exclusion criteria and concept applications, clinical data, complications, remedies and challenges that will provide a general understanding of the All-on-4™ philosophy.
MACHINIMA REVIEWS
Authors: Johnson Phylis , Padilla-Miller Alina , Jegathesan Jay Jay 
Published: April 2012

EDITOR’S NOTE: MACHINIMA’S IMPACT THROUGH AN ACADEMIC LENS: REVIEWING WINNING WORKS AT INTERNATIONAL EDUCATIONAL VENUES
THE ISTE MACHINIMA FEST 2011
BREAKING DOWN THE BARRIERS: MACHINIMUWA
The Auditor-Audit Firm Relationship and Its Effect on Burnout and Turnover Intention
Authors: Herda David N. , Lavelle James J. 
Published: April 2012

SYNOPSIS:
Auditor burnout is an important issue in public accounting, as burnout has negative consequences for both the auditor and the audit firm. We examine how social-exchange relationships between auditors and their firm affect auditor burnout and turnover intention. Using a sample of 204 auditors at two accounting firms, we find that perceived fair treatment by the firm predicts perceived support from the firm, and perceived support predicts auditor commitment to the firm. We find that commitment is negatively related to auditor burnout and turnover intention and burnout is positively related to turnover intention. We also find that perceived firm fairness is directly associated with reduced levels of auditor burnout and turnover intention. The results underscore the important role that organizational fairness plays in engendering a social-exchange relationship between auditors and their firm, leading to reduced levels of burnout and turnover intention, benefitting both the auditor and the firm.
Data Availability: Please contact the first author.
Graphical representations of membership functions of maximum and minimum of two fuzzy numbers using computer program
Authors: Shirin Shapla , Saha Goutam 
Published: April 2012

The set of real numbers R is linearly ordered, but in the fuzzy set theory, this relation is true only for some set of fuzzy numbers where the sets of fuzzy numbers are expressed as the linguistic variables. Different types of Fuzzy machines based on fuzzy logic have been invented where fuzzy logics are described by fuzzy numbers and the fuzzy numbers are needed to compare. Besides these, many techniques are available to assist decision-makers to compare different fuzzy numbers. For these reasons, it is necessary to compute the maximum and the minimum of fuzzy numbers. Till now many researchers introduced different methods for computation, which are done by hand calculation, but these are very disgusting and time consuming to us. In this paper, we presents an algorithm to compute the maximum and the minimum of any two triangular fuzzy numbers, so that one can compare two fuzzy numbers easily in a short time and visualize the analytic expressions and the graphical representations of the maximum and the minimum of any two triangular fuzzy numbers. By using CAS (MATHEMATICA 7.0), the algorithm is implemented in a computer program in order to do these. This algorithm can easily be extended to apply for any type of fuzzy numbers which are comparable. Even it is able to compare more than two fuzzy numbers by comparing the maximum fuzzy number or minimum fuzzy number with another new fuzzy number.DOI: http://dx.doi.org/10.3329/ganit.v31i0.10313GANIT J. Bangladesh Math. Soc. (ISSN 1606-3694) 31 (2011) 105-115
Bosentan Effects in Hypoxic Pulmonary Vasoconstriction: Preliminary Study in Subjects with or without High Altitude Pulmonary Edema‐History
Authors: Pham Isabelle , Wuerzner Grégoire , Richalet Jean‐Paul , Peyrard Séverine , Azizi Michel 
Published: April 2012

Hypoxia‐induced pulmonary vasoconstriction in patients with a medical history of high‐altitude pulmonary edema (HAPE) may involve activation of the endothelin‐1 (ET‐1) pathway. We, therefore, compared the effect of the ETA/ETB receptor antagonist, bosentan, on pulmonary artery systolic pressure (PASP) in healthy subjects with (HS: HAPE subjects, n=5) or without a HAPE‐history (CS: Control subjects, n=10). A double‐blind, placebo‐controlled, randomized, crossover design was performed in order to study the effects on PASP of a single oral dose of bosentan (250 mg) after 90 min exposure to normobaric hypoxia (FiO2=0.12). In normoxia, PASP, evaluated by echocardiography, was 23.4±2.7 mmHg in CS and 28±5.8 mmHg in HS (NS). During the placebo period, hypoxia induced a significant decrease in SaO2, PaO2 and PCO2 and increase in pH in both CS and HS. Pulmonary arterial systolic pressure was also significantly increased (+8.5±5.0 mmHg in CS; +13.4±3.1 mmHg in HS) and reached significantly higher levels in HS than in CS (P=0.02). Bosentan significantly but similarly blunted the hypoxia‐induced increase in PASP in both CS (Bosentan: 27.0±3.3 mmHg; placebo: 32.1±3.5 mmHg; P<0.01) and HS (Bosentan: 35.0±2.9 mmHg; placebo: 41.4±7.6 mmHg; P<0.05), (CS 5.2±5.3 vs. HS −6.4±5.2 mmHg, NS). Bosentan did not have a major effect on the hypoxia‐induced changes in blood gas, or on cardiac output (CO) and systemic blood pressure (SBP), which were not modified by hypoxia. Plasma ET‐1 in hypoxia during the bosentan period was 2.8 times higher than during for both CS and HS. A single oral dose of bosentan similarly blunted the hypoxia‐induced increase in PASP both in healthy and HAPE‐susceptible subjects, without altering CO or SBP.