bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utility of N terminal pro brain natriuretic peptide in elderly patients
Authors: Sivakumar R , Wellsted D , Parker K , Lynch M , Ghosh P , Khan S A 
Published: March 2006

Abstract

Objective
To evaluate the utility of N terminal pro brain natriuretic peptide (NT-proBNP) as a diagnostic marker for diastolic dysfunction or failure, systolic dysfunction, and significant valve disorders in patients over 75 years.

Design
Cohort study.

Setting
Outpatient echocardiography service in a district general hospital.

Participants
100 consecutive patients.

Main outcome measures
Sensitivity, specificity, positive predictive values, negative predictive values, and area under receiver operating characteristic curve for NT-proBNP assay in the diagnosis of left ventricular diastolic dysfunction or failure, systolic dysfunction, and significant valve disorders.

Results
For diagnosis of systolic dysfunction NT-proBNP level of 424 pg/ml had a sensitivity of 96%, specificity of 45%, positive predictive value of 36%, and negative predictive value of 96%. The area under the curve was 0.71 (95% confidence intervals: 0.69 to 0.89). In valve heart disease, level of 227 pg/ml had sensitivity of 91%, specificity of 43%, positive predictive value of 40%, and negative predictive value of 92%. Patients with diastolic dysfunction/failure had lower plasma concentrations.

Conclusions
This study showed that NT-proBNP had excellent negative predictive value for systolic dysfunction and significant valve disorders in very elderly patients. It increased significantly in systolic dysfunction, valve heart disease, and atrial fibrillation. NT-proBNP is not useful in the diagnosis of diastolic dysfunction or diastolic heart failure using standard echocardiography criteria.
Epithelial-Restricted Gene Profile of Primary Cultures from Human Prostate Tumors: A Molecular Approach to Predict Clinical Behavior of Prostate Cancer
Authors: Nanni Simona , Priolo Carmen , Grasselli Annalisa , D'Eletto Manuela , Merola Roberta , Moretti Fabiola , Gallucci Michele , De Carli Piero , Sentinelli Steno , Cianciulli Anna Maria , Mottolese Marcella , Carlini Paolo , Arcelli Diego , Helmer-Citterich Mauro , Gaetano Carlo , Loda Massimo , Pontecorvi Alfredo , Bacchetti Silvia , Sacchi Ada , Farsetti Antonella 
Published: March 2006

Abstract
The histopathologic and molecular heterogeneity of prostate cancer and the limited availability of human tumor tissue make unraveling the mechanisms of prostate carcinogenesis a challenging task. Our goal was to develop an ex vivo model that could be reliably used to define a prognostic signature based on gene expression profiling of cell cultures that maintained the tumor phenotype. To this end, we derived epithelial cultures from tissue explanted from 59 patients undergoing radical prostatectomy or cistoprostatectomy because of prostate benign hyperplasia/prostate cancer or bladder carcinoma. Patient selection criteria were absence of hormonal neoadjuvant treatment before surgery and diagnosis of clinically localized disease. Using this unique experimental material, we analyzed expression of 22,500 transcripts on the Affymetrix Human U133A GeneChip platform (Affymetrix, Inc., High Wycombe, United Kingdom). Cultures from normal/hyperplastic tissues with a prevalent luminal phenotype and from normal prostate epithelial tissue with basal phenotype (PrEC) served as controls. We have established a large number of prostate primary cultures highly enriched in the secretory phenotype. From them, we derived an epithelial-restricted transcriptional signature that (a) differentiated normal from tumor cells and (b) clearly separated cancer-derived lines into two distinct groups, which correlated with indolent or aggressive clinical behavior of the disease. Our findings provide (a) a method to expand human primary prostate carcinoma cells with a luminal phenotype, (b) a powerful experimental model to study primary prostate cancer biology, and (c) a novel means to characterize these tumors from a molecular genetic standpoint for prognostic and/or predictive purposes. (Mol Cancer Res 2006;4(2):79–92)
Nuclear Factor-κB Dimer Exchange Promotes a p21waf1/cip1 Superinduction Response in Human T Leukemic Cells
Authors: Chang Pei-Yun , Miyamoto Shigeki 
Published: March 2006

AbstractThe nuclear factor-κB (NF-κB)/Rel transcription factors are recognized as critical apoptosis regulators. We reported previously that NF-κB contributes to chemoresistance of CEM human T leukemic cells in part through its ability to induce p21waf1/cip1. Here, we provide evidence that sequential NF-κB-activating signals induce heightened NF-κB DNA binding and p21waf1/cip1 induction in CEM and additional T leukemic cell lines. This response arises from exceedingly low basal expression of the p105/p50 NF-κB subunit encoded by the NFKB1 gene in these cell lines. An initial NF-κB activation event enhances the recruitment of p65 and ELF1 to the NFKB1 promoter, leading to p65- and ELF1-dependent synthesis of p105/p50, which promotes an exchange of NF-κB complexes to p50-containing complexes with an increased DNA-binding activity to certain NF-κB target elements. Subsequent stimulation of these cells with an anticancer agent, etoposide, results in augmented NF-κB-dependent p21waf1/cip1 induction and increased chemoresistance of the leukemia cells. Thus, we propose that low basal NFKB1 expression coupled with sequential NF-κB activation events can promote increased chemoresistance in certain T leukemic cells. (Mol Cancer Res 2006;4(2):101–12)
Overcoming Physiologic Barriers to Cancer Treatment by Molecularly Targeting the Tumor Microenvironment
Authors: Cairns Rob , Papandreou Ioanna , Denko Nicholas 
Published: March 2006

AbstractIt is widely recognized that the vasculature of the tumor is inadequate to meet the demands of the growing mass. The malformed vasculature is at least in part responsible for regions of the tumor that are hypoxic, acidotic, and exposed to increased interstitial fluid pressure. These unique aspects of the tumor microenvironment have been shown to act as barriers to conventional chemotherapy or radiation-based therapies. It now seems that while the vasculature initiates these tumor-specific conditions, the cells within the tumor respond to these stresses and add to the unique solid tumor physiology. Gene expression changes have been reported in the tumor for vascular endothelial growth factor, carbonic anhydrase IX, and pyruvate dehydrogenase kinase 1. The activity of these gene products then influences the tumor physiology through alterations in vascular permeability and interstitial fluid pressure, extracellular acidosis, and mitochondrial oxygen consumption and hypoxia, respectively. Novel molecular strategies designed to interfere with the activities of these gene products are being devised as ways to overcome the physiologic barriers in the tumor to standard anticancer therapies. (Mol Cancer Res 2006;4(2):61–70)
Negotiating to Control Weapons of Mass Destruction in North Korea
Authors: Clemens Walter 
Published: March 2006

AbstractNegotiations to control and perhaps eliminate North Korea's weapons of mass destruction (WMD) appeared to achieve positive results in the 1990s. But these positive trends reversed direction in 2001–2004 under President George W. Bush. Why? This essay weighs six possible explanations. 1. progress in the 1990s as a mirage; 2. cultural differences; 3. distrust of international agreements; 4. perceptions regarding the utility of WMD; 5. internal divisions within each government and society; and 6. ulterior motives.The evidence suggests that the sixth explanation carries the most weight. Top leaders in the Democratic People's Republic of Korea (DPRK) as well as in the United States had priorities other than arms control. Each side used arms control negotiations as an instrument to promote its political and economic agenda in other realms. Pyongyang demanded large and certain rewards to give up its main bargaining chips. North Korea's negotiating behavior suggested some willingness to freeze or eliminate WMD programs if the price were right. But Kim Jong Il's regime clearly saw its nuclear and missile capabilities as major assets not to be traded away except for very substantial security and economic rewards. For its part, the Bush White House probably worried that any accord with Pyongyang would impede Washington's larger political, military, and economic ambitions, including deployment of a national missile defense (NMD). There was also a subjective element: President Bush probably loathed Kim Jong Il and did not relish the prospect of making any compromises with evil incarnate. For enlightened self-interest to prevail, the parties could benefit from greater empathy and a quest for mutual rather than one-sided gain.
From Individual State Preferences to Collective Decisions: An Analytic Account of the 1995 NPT Review and Extension Conference
Authors: Essis Essoh 
Published: March 2006

AbstractThis article provides a framework for the analysis of the Non-Proliferation Treaty's five-year review conferences and of similar multilateral collective security policy-making fora from a truly global perspective. Factor and discriminant analytic models have made it possible to broaden the scope of inquiry beyond the interests, capabilities and preferences of the few rich and powerful states. Additionally, the use of participant observation, historical analysis and legal hermeneutics techniques provides a much needed qualitative perspective that complements and refines the interpretation of quantitative findings.
Dynamical Processes of Equatorial Atmospheric Angular Momentum
Authors: Feldstein Steven B. 
Published: March 2006

AbstractThe dynamical processes that drive intraseasonal equatorial atmospheric angular momentum (EAAM) fluctuations are examined with the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data. The primary methodology involves the regression of relevant variables including the equatorial bulge, mountain, and friction torques, surface pressure, streamfunction, and outgoing longwave radiation, against the time derivative of the two components and the amplitude of the EAAM vector.The results indicate that the observed 10-day westward rotation of the EAAM vector corresponds to the propagation of a zonal wavenumber-1, antisymmetric, Rossby wave normal mode. Additional findings suggest that fluctuations in the amplitude of the EAAM vector are driven by poleward-propagating Rossby waves excited by the latent heating within equatorial mixed Rossby–gravity waves and also by wave–wave interaction among planetary waves. Both of these processes can induce surface pressure anomalies that amplify the EAAM vector via the equatorial bulge torque. The Antarctic and Greenland mountain torques were found to drive large fluctuations in the amplitude of the EAAM vector. Both the friction torque and wave–zonal-mean flow interaction were shown to dampen the EAAM amplitude fluctuations.A comparison of the EAAM dynamics in the atmosphere with that in an aquaplanet GCM suggests that the mountain torque also drives fluctuations in the phase speed of the atmospheric wave field associated with the EAAM vector, and it confines the wave–wave interaction to planetary scales.
A Theory of Gravity Wave Absorption by a Boundary Layer
Authors: Smith Ronald B. , Jiang Qingfang , Doyle James D. 
Published: March 2006

Abstract
A one-layer model of the atmospheric boundary layer (BL) is proposed to explain the nature of lee-wave attenuation and gravity wave absorption seen in numerical simulations. Two complex coefficients are defined: the compliance coefficient and the wave reflection coefficient. A real-valued ratio of reflected to incident wave energy is also useful. The key result is that, due to horizontal friction, the wind response in the BL is shifted upstream compared to the phase of disturbances in the free atmosphere. The associated flow divergence modulates the thickness of the BL so that it partially absorbs incident gravity waves. A simple expression is derived relating the reflection coefficient to the attenuation and wavelength shift of trapped lee waves. Results agree qualitatively with the numerical simulations, including the effects of increased surface roughness and heat flux.
Low-Order Stochastic Mode Reduction for a Prototype Atmospheric GCM
Authors: Franzke Christian , Majda Andrew J. 
Published: March 2006

Abstract
This study applies a systematic strategy for stochastic modeling of atmospheric low-frequency variability to a three-layer quasigeostrophic model. This model climate has reasonable approximations of the North Atlantic Oscillation (NAO) and Pacific–North America (PNA) patterns. The systematic strategy consists first of the identification of slowly evolving climate modes and faster evolving nonclimate modes by use of an empirical orthogonal function (EOF) decomposition in the total energy metric. The low-order stochastic climate model predicts the evolution of these climate modes a priori without any regression fitting of the resolved modes. The systematic stochastic mode reduction strategy determines all correction terms and noises with minimal regression fitting of the variances and correlation times of the unresolved modes. These correction terms and noises account for the neglected interactions between the resolved climate modes and the unresolved nonclimate modes. Low-order stochastic models with 10 or less resolved modes capture the statistics of the original model very well, including the variances and temporal correlations with high pattern correlations of the transient eddy fluxes. A budget analysis establishes that the low-order stochastic models are highly nonlinear with significant contributions from both additive and multiplicative noise. This is in contrast to previous stochastic modeling studies. These studies a priori assume a linear model with additive noise and regression fit the resolved modes. The multiplicative noise comes from the advection of the resolved modes by the unresolved modes. The most straightforward low-order stochastic climate models experience climate drift that stems from the bare truncation dynamics. Even though the geographic correlation of the transient eddy fluxes is high, they are underestimated by a factor of about 2 in the a priori procedure and thus cannot completely overcome the large climate drift in the bare truncation. Also, variants of the reduced stochastic modeling procedure that experience no climate drift with good predictions of both the variances and time correlations are discussed. These reduced models without climate drift are developed by slowing down the dynamics of the bare truncation compared with the interactions with the unresolved modes and yield a minimal two-parameter regression fitting strategy for the climate modes. This study points to the need for better optimal basis functions that optimally capture the essential slow dynamics of the system to obtain further improvements for the reduced stochastic modeling procedure.
Effective Refractive Indices of Water and Sulfate Drops Containing Absorbing Inclusions
Authors: Erlick Carynelisa 
Published: March 2006

Abstract
In this study the range of visible refractive indices and single-scattering albedos that can be obtained using various mean field formulations for mixtures of two components, where one component absorbs in the visible, is explored. For calculations of global radiative forcing and climate response, such formulations provide a convenient way to take into account internal mixing of aerosol components without the computational burden of a more exact theory, provided that the limits of their applicability are kept in mind. Within those limits, the results show that for water and sulfate drops containing dust and soot inclusions, the degree of interaction between the electric fields of neighboring inclusions is not important. However, the shape and size of the inclusions can cause a variation in the effective imaginary refractive index of up to a factor of 3.4 and a variation in the single-scattering albedo of up to 0.18 in absolute value.
Empirically Evaluating Divergence Rates of Atmospheric Trajectories
Authors: Eshel Gidon 
Published: March 2006

Abstract
Observed Northern Hemisphere divergence rates of phase-space trajectories initially emanating from neighboring points are estimated, using a simple, seasonal, weakly GCM-dependent linear method applied to Ertel potential vorticity on the 315-K isentrope. Using the same data and essentially the same method, atmospheric persistence, the rate of trajectory departure from an initial state, is also estimated. With the results applying only to the truncated state considered (comprising only a single variable observed at a single level), it is found that the time scale for divergence of two, initially reasonably similar, trajectories is about 4–6 days, between the time scales of cyclogenesis and blocking. It is also found that the time scale for divergence of a given trajectory from an earlier point along it is about 3–5 days.
Conditions That Inhibit the Spontaneous Radiation of Spiral Inertia–Gravity Waves from an Intense Mesoscale Cyclone
Authors: Schecter David A. , Montgomery Michael T. 
Published: March 2006

Abstract
The spontaneous radiation of spiral inertia–gravity (IG) waves from monotonic cyclones is reexamined. Such radiation can occur most significantly in a parameter regime that includes strong supercell mesocyclones and hurricanes. First, linear theory is reviewed. In linear theory, a generic deformation of the cyclone excites discrete vortex Rossby (VR) waves. Each VR wave emits a frequency-matched spiral IG wave into the environment. The emission has positive feedback on the VR wave, causing both to grow. However, the VR wave also deposits wave activity into its critical layer at the radius r*. If the radial gradient of potential vorticity at r* exceeds a threshold, critical layer absorption suppresses the radiative instability.
On the other hand, numerical simulations of a shallow-water cyclone show that nonlinear changes to the critical layer can revive a damped VR wave and its radiation field after a brief period of decay. For such revival, it suffices that Ωb/|γ| ≳ 1. This inequality contains two characteristic frequencies. The denominator |γ| is the absolute value of the (negative) growth rate of the damped wave. The numerator Ωb is the mixing rate of the critical layer, which is proportional to the square root of the initial wave amplitude.
After damping is reversed, the radiative VR wave exhibits undulatory growth. Analysis shows that growth proceeds because radiation steadily removes negative wave activity from the cyclone. Secondary amplitude oscillations are due to back-and-forth exchanges of positive wave activity between the VR wave and its critical layer.
Variability of the Southern Hemisphere Winter Split Flow—A Case of Two-Way Reinforcement between Mean Flow and Eddy Anomalies
Authors: Yang Xiaosong , Chang Edmund K. M. 
Published: March 2006

Abstract
A new split-jet index is defined in this study, and composites based on this index show that the split-flow regime is characterized by a cold–warm–cold tripolar temperature anomaly in the South Pacific that extends equatorward from the Southern Hemisphere (SH) high latitudes, while nonsplit flow occurs when the phase of the tripolar temperature anomaly is reversed. Analyses of the heat budget reveal that the temperature anomalies associated with the split/nonsplit flow are mainly forced by mean flow advection instead of local diabatic heating or convergence of eddy heat fluxes. Localized Eliassen–Palm (E–P) flux diagnostics suggest that the zonal wind anomalies are maintained by the eddy vorticity flux anomalies.
These diagnostic results are confirmed by numerical experiments conducted using a stationary wave model forced by observed eddy forcings and diabatic heating anomalies. The model results show that the effects of the vorticity flux dominates over those of the heat flux, which tend to dampen the flow anomalies, and that tropical diabatic heating anomalies are not important in maintaining the split-/nonsplit-flow anomalies.
The organization of high-frequency eddies by the low-frequency split/nonsplit jet is also studied. Two sets of experiments using a linear storm-track model initialized with random initial perturbations superposed upon the split- and nonsplit-jet basic state, respectively, have been conducted. Model results show that the storm-track anomalies that are organized by the split/nonsplit jet are consistent with observed storm-track anomalies, thus demonstrating that the low-frequency split/nonsplit jet acts to organize the high-frequency eddies.
The results of this paper directly establish that there is a two-way reinforcement between eddies and mean flow anomalies in the low-frequency variability of the SH winter split jet.
On the Application of the Dynamic Smagorinsky Model to Large-Eddy Simulations of the Cloud-Topped Atmospheric Boundary Layer
Authors: Kirkpatrick M. P. , Ackerman A. S. , Stevens D. E. , Mansour N. N. 
Published: March 2006

Abstract
In this paper the dynamic Smagorinsky model originally developed for engineering flows is adapted for simulations of the cloud-topped atmospheric boundary layer in which an anelastic form of the governing equations is used. The adapted model accounts for local buoyancy sources, vertical density stratification, and poor resolution close to the surface and calculates additional model coefficients for the subgrid-scale fluxes of potential temperature and total water mixing ratio. Results obtained with the dynamic model are compared with those obtained using two nondynamic models for simulations of a nocturnal marine stratocumulus cloud deck observed during the first research flight of the second Dynamics and Chemistry of Marine Stratocumulus (DYCOMS-II) field experiment. The dynamic Smagorinsky model is found to give better agreement with the observations for all parameters and statistics. The dynamic model also gives improved spatial convergence and resolution independence over the nondynamic models. The good results obtained with the dynamic model appear to be due primarily to the fact that it calculates minimal subgrid-scale fluxes at the inversion. Based on other results in the literature, it is suggested that entrainment in the DYCOMS-II case is due predominantly to isolated mixing events associated with overturning internal waves. While the behavior of the dynamic model is consistent with this entrainment mechanism, a similar tendency to switch off subgrid-scale fluxes at an interface is also observed in a case in which gradient transport by small-scale eddies has been found to be important. This indicates that there may be problems associated with the application of the dynamic model close to flow interfaces. One issue here involves the plane-averaging procedure used to stabilize the model, which is not justified when the averaging plane intersects a deforming interface. More fundamental, however, is that the behavior may be due to insufficient resolution in this region of the flow. The implications of this are discussed with reference to both dynamic and nondynamic subgrid-scale models, and a new approach to turbulence modeling for large-eddy simulations is proposed.