bluuebunny/crossref_metadata_2025 huggingface dataset:
Third-Line Therapy for Advanced Non-Small-Cell Lung Cancer Patients: A Feasible Therapeutic Option?
Authors: Galetta Domenico , Rossi Antonio , Colucci Giuseppe , Gebbia Vittorio
Published: February 2010

Two decades ago best supportive care was considered a valid therapeutic option for advanced non-small cell lung cancer (NSCLC) patients until the evidence derived from meta-analysis showed symptom improvement and a survival advantage from systemic chemotherapy. A further advantage was reported when docetaxel and pemetrexed were used as second-line treatment after failure of first-line platinum-based chemotherapy. Furthermore, the biologic therapies targeting the epidermal growth factor receptor – erlotinib and gefitinib – have modified the therapeutic approach to second- and third-line treatment of NSCLC patients. In fact, to date, erlotinib is the only drug to be licensed for third-line therapy worldwide. So, third-line represents a new frontier to be assessed in advanced NSCLC patients. Third-line therapy is very hard to define correctly as it is difficult to interpret the currently available evidence-based data. A better knowledge of cellular biology will certainly encourage clinical research and could allow oncologists to best select patients and treatments. Here we review the state of the art of third-line therapy in the treatment of NSCLC patients.
Variation in the Frequency of Intracerebral Haemorrhage and Ischaemic Stroke in China: A National, Multicentre, Hospital Register Study
Authors: Wei Jade W. , Arima Hisatomi , Huang Yining , Wang Ji-Guang , Yang Qidong , Liu Zhenguo , Liu Ming , Lu Chuanzhen , Heeley Emma L. , Anderson Craig S.
Published: February 2010

Background: Intracerebral haemorrhage (ICH) accounts for about one third of all strokes in China, a proportion that is three times higher than in Western populations. We aimed to determine the frequency distribution of ICH in China. Methods: Using the ChinaQUEST hospital register database, the proportional frequency of ICH was determined by region and city location. Linear regression analysis was then performed to evaluate associations between the frequency of ICH and distribution of risk factors by city. Results: Proportional frequency of ICH was 25% overall, but varied markedly across major geographical regions ranging from 11 to 36%. The differences between cities were even more profound, with the age- and sex-standardised proportional frequencies ranging from 5% in Guangzhou to 55% in Baoji. Significant associations were found between the proportional frequency of ICH and history of diabetes, hyperlipidaemia, and a high body mass index. Notably, cities with higher frequencies of diabetic, hyperlipidaemic or overweight individuals tended to have lower frequencies of ICH. Conclusions: Considerable interregional variation in the distribution of ICH in China can be partially explained by differences in distribution of risk factors in the population.
Wake-Up Stroke: Clinical and Neuroimaging Characteristics
Authors: Silva Gisele S. , Lima Fabricio O. , Camargo Erica C.S. , Smith Wade S. , Singhal Aneesh B. , Greer David M. , Ay Hakan , Lev Michael H. , Harris Gordon J. , Halpern Elkan F. , Sonni Shruti , Koroshetz Walter , Furie Karen L.
Published: February 2010

Background: Approximately 25% of ischemic stroke patients awaken with neurological deficits. In these patients, in whom the time from symptom onset is uncertain, brain imaging is a potential strategy to characterize the ischemia duration and the presence of salvageable brain tissue. Methods: We prospectively evaluated consecutive patients with acute ischemic stroke. CT angiography and CT perfusion (CTP) were performed in patients within 24 h of symptom onset. The patients were classified into ‘known onset’, ‘indefinite onset but not on awakening’ and ‘wake-up stroke’ groups. Results: Of 676 patients evaluated, 420 had known-onset strokes, 131 wake-up strokes and 125 strokes with an indefinite time of symptom onset. Ischemic lesion volumes were higher in patients with indefinite-onset strokes (p = 0.04). The frequencies of CTP mismatch and of large-vessel intracranial occlusions were similar among the groups (p = 0.9 and p = 0.2, respectively). Conclusion: The considerable prevalence of CTP mismatch and of intracranial artery occlusions in our patients with wake-up strokes suggests that arterial and perfusion imaging might be particularly important in this population. Revised indications for thrombolysis by using imaging-based protocols might offer these patients the prospect of receiving acute stroke treatment even without a clear time of symptom onset.
Multiple Sclerosis and the Accumulation of Iron in the Basal Ganglia: Quantitative Assessment of Brain Iron Using MRI T2 Relaxometry
Authors: Burgetova A. , Seidl Z. , Krasensky J. , Horakova D. , Vaneckova M.
Published: February 2010

The aim of this work was to quantify the accumulation of iron in the basal ganglia in multiple sclerosis (MS) patients and in a control group, and to investigate the relationship between iron accumulation and other parameters assessed in MS, i.e. lesion load (LL) and brain parenchymal fraction (BPF). Magnetic resonance imaging T2 relaxometry was used for the measurement. 970 patients with clinically definite MS and 117 controls were examined. Patients were divided into three subgroups according to LL and BPF. This work provides quantitative evidence of increased iron accumulation in the basal ganglia in MS patients in comparison to healthy controls. We also found that in the subgroup with small LL value, iron accumulation is higher than in the subgroup with large LL value. The hypothesis of a neurodegenerative component of MS is supported by the changes in iron content in the brain.
Modelling Childhood Caries Using Parametric Competing Risks Survival Analysis Methods for Clustered Data
Authors: Stephenson J. , Chadwick B.L. , Playle R.A. , Treasure E.T.
Published: February 2010

Caries in primary teeth is an ongoing issue in children’s dental health. Its quantification is affected by clustering of data within children and the concurrent risk of exfoliation of primary teeth. This analysis of caries data of 103,776 primary molar tooth surfaces from a cohort study of 2,654 British children aged 4–5 years at baseline applied multilevel competing risks survival analysis methodology to identify factors significantly associated with caries occurrence in primary tooth surfaces in the presence of the concurrent risk of exfoliation, and assessed the effect of exfoliation on caries development. Multivariate multilevel parametric survival models were applied at surface level to the analysis of the sound-carious and sound-exfoliation transitions to which primary tooth surfaces are subject. Socio-economic class, fluoridation status and surface type were found to be the strongest predictors of primary caries, with the highest rates of occurrence and lowest median survival times associated with occlusal surfaces of children from poor socio-economic class living in non-fluoridated areas. The concurrent risk of exfoliation was shown to reduce the distinction in survival experience between different types of surfaces, and between surfaces of teeth from children of different socio-economic class or fluoridation status. Clustering of data had little effect on inferences of parameter significance.
A Prospective Study of SCA3 Gait Ataxia Described through a Markovian Method
Authors: Camey Suzi , Jardim Laura Bannach , Kieling Christian , Saute Jonas Alex Morales , Vigo Álvaro
Published: February 2010

Background: Studies on the natural history of rare, chronic diseases like spinocerebellar ataxia 3 (SCA3) are hard to be done, since patients enter the study with variable disease durations and are followed up at irregular intervals. Aims: Our purpose was to use all the available data to describe the progression of gait ataxia in a long-term cohort of patients with SCA3 through a markovian method. Materials and Methods: SCA3 patients were recruited between 1998 and 2005 and were invited to annual neurological follow-ups until 2007. Gait ataxia was described through a mean score graph and a mean trajectory graph. Results: We followed up 105 patients; at baseline, the mean age and disease duration were, 40.5 (SD = 12.6) and 7.7 (SD = 5.8) years, respectively. The mean time to reach stages 1, 2, 3 and 4 of gait ataxia were 3, 5.4, 10.8 and 19.4 years of disease duration. The mean score graph was unsmooth, showing several unlikely ups and downs. The mean trajectory graph produced a continuous curve. Conclusion: The markovian method described the natural history of gait ataxia without any a posteriori adjustment of data and allowed statistical comparisons between subgroups. This method will be useful in future clinical trials in this and in other chronic degenerative diseases.
Incidence of Spinal Cord Injury Worldwide: A Systematic Review
Authors: van den Berg M.E.L. , Castellote J.M. , Mahillo-Fernandez I. , de Pedro-Cuesta J.
Published: February 2010

Background: Incidence studies of spinal cord injury (SCI) are important for health-care planning and epidemiological research. This review gives a quantitative update on SCI epidemiology worldwide through a statistical evaluation of incidence rates. Methods: A systematic review was conducted. For each study, the crude rate ratio was calculated and, when possible, age- and gender-adjusted incidence rate ratios with 95% CI were determined by direct adjustment or using Poisson regression. Results: Thirteen studies were included. Annual crude incidence rates in traumatic SCI varied from 12.1 per million in The Netherlands to 57.8 per million in Portugal. Compared to the Portuguese reference study, incidence rates showed a 3-fold variation, with the highest rates in Canada and Portugal. Most traumatic SCI studies showed a bimodal age distribution. The first peak was found in young adults between 15 and 29 years and a second peak in older adults (mostly ≧65 years). Motor vehicle accidents and falls were the most prevalent causes of injury accounting for nearly equal percentages. In contrast, another age pattern in non-traumatic SCI reflected steadily increasing incidence with advancing age. Conclusions: The results show significant variation in SCI incidence with changing epidemiological patterns. A trend towards increased incidence in the elderly was observed, likely due to falls and non-traumatic injury.
Molecular Magnetic Resonance Imaging of Myocardial Angiogenesis After Acute Myocardial Infarction
Authors: Oostendorp Marlies , Douma Kim , Wagenaar Allard , Slenter Jos M.G.M. , Hackeng Tilman M. , van Zandvoort Marc A.M.J. , Post Mark J. , Backes Walter H.
Published: February 2010

Background—

Angiogenesis is a natural mechanism to restore perfusion to the ischemic myocardium after acute myocardial infarction (MI). Therapeutic angiogenesis is being explored as a novel treatment for MI patients; however, sensitive, noninvasive in vivo measures of therapeutic efficacy are lacking and need to be developed. Here, a molecular magnetic resonance imaging method is presented to noninvasively image angiogenic activity in vivo in a murine model of MI with cyclic Asn-Gly-Arg (cNGR)–labeled paramagnetic quantum dots (pQDs). The tripeptide cNGR homes specifically to CD13, an aminopeptidase that is strongly upregulated during myocardial angiogenesis.

Methods and Results—

Acute MI was induced in male Swiss mice via permanent ligation of the left anterior descending coronary artery. Molecular magnetic resonance imaging was performed 7 days after surgery and up to 2 hours after intravenous contrast agent administration. Injection of cNGR-pQDs resulted in a strong negative contrast that was located mainly in the infarcted myocardium. This negative contrast was significantly less in MI mice injected with unlabeled pQDs and in sham-operated mice injected with cNGR-pQDs. Validation with ex vivo 2-photon laser scanning microscopy revealed a strong colocalization of cNGR-pQDs with vascular endothelial cells, whereas unlabeled pQDs were mostly extravasated and diffused through the tissue. Additionally, 2-photon laser scanning microscopy demonstrated significant microvascular remodeling in the infarct/border zones compared with remote myocardium.

Conclusions—

cNGR-pQDs allow selective, noninvasive detection of angiogenic activity in the infarcted heart with the use of in vivo molecular magnetic resonance imaging and ex vivo 2-photon laser scanning microscopy.
Association of Diet, Exercise, and Smoking Modification With Risk of Early Cardiovascular Events After Acute Coronary Syndromes
Authors: Chow Clara K. , Jolly Sanjit , Rao-Melacini Purnima , Fox Keith A.A. , Anand Sonia S. , Yusuf Salim
Published: February 2010

Background—

Although preventive drug therapy is a priority after acute coronary syndrome, less is known about adherence to behavioral recommendations. The aim of this study was to examine the influence of adherence to behavioral recommendations in the short term on risk of cardiovascular events.

Methods and Results—

The study population included 18 809 patients from 41 countries enrolled in the Organization to Assess Strategies in Acute Ischemic Syndromes (OASIS) 5 randomized clinical trial. At the 30-day follow-up, patients reported adherence to diet, physical activity, and smoking cessation. Cardiovascular events (myocardial infarction, stroke, cardiovascular death) and all-cause mortality were documented to 6 months. About one third of smokers persisted in smoking. Adherence to neither diet nor exercise recommendations was reported by 28.5%, adherence to either diet or exercise by 41.6%, and adherence to both by 29.9%. In contrast, 96.1% of subjects reported antiplatelet use, 78.9% reported statin use, and 72.4% reported angiotensin-converting enzyme/angiotensin receptor blocker use. Quitting smoking was associated with a decreased risk of myocardial infarction compared with persistent smoking (odds ratio, 0.57; 95% confidence interval, 0.36 to 0.89). Diet and exercise adherence was associated with a decreased risk of myocardial infarction compared with nonadherence (odds ratio, 0.52; 95% confidence interval, 0.4 to 0.69). Patients who reported persistent smoking and nonadherence to diet and exercise had a 3.8-fold (95% confidence interval, 2.5 to 5.9) increased risk of myocardial infarction/stroke/death compared with never smokers who modified diet and exercise.

Conclusions—

Adherence to behavioral advice (diet, exercise, and smoking cessation) after acute coronary syndrome was associated with a substantially lower risk of recurrent cardiovascular events. These findings suggest that behavioral modification should be given priority similar to other preventive medications immediately after acute coronary syndrome.

Clinical Trial Registration Information—

URL: http://clinicaltrials.gov/ct2/show/NCT00139815. Unique identifier: NCT00139815.
Activation of Proteinase-Activated Receptor 2 Stimulates Soluble Vascular Endothelial Growth Factor Receptor 1 Release via Epidermal Growth Factor Receptor Transactivation in Endothelial Cells
Authors: Al-Ani Bahjat , Hewett Peter W. , Cudmore Melissa J. , Fujisawa Takeshi , Saifeddine Mahmoud , Williams Hannah , Ramma Wenda , Sissaoui Samir , Jayaraman Padma-Sheela , Ohba Motoi , Ahmad Shakil , Hollenberg Morley D. , Ahmed Asif
Published: February 2010

The proteinase-activated receptor 2 (PAR-2) expression is increased in endothelial cells derived from women with preeclampsia, characterized by widespread maternal endothelial damage, which occurs as a consequence of elevated soluble vascular endothelial growth factor receptor-1 (sVEGFR-1; commonly known as sFlt-1) in the maternal circulation. Because PAR-2 is upregulated by proinflammatory cytokines and activated by blood coagulation serine proteinases, we investigated whether activation of PAR-2 contributed to sVEGFR-1 release. PAR-2–activating peptides (SLIGRL-NH2and 2-furoyl-LIGRLO-NH2) and factor Xa increased the expression and release of sVEGFR-1 from human umbilical vein endothelial cells. Enzyme-specific, dominant-negative mutants and small interfering RNA were used to demonstrate that PAR-2–mediated sVEGFR-1 release depended on protein kinase C-β1and protein kinase C-ε, which required intracellular transactivation of epidermal growth factor receptor 1, leading to mitogen-activated protein kinase activation. Overexpression of heme oxygenase 1 and its gaseous product, carbon monoxide, decreased PAR-2–stimulated sVEGFR-1 release from human umbilical vein endothelial cells. Simvastatin, which upregulates heme oxygenase 1, also suppressed PAR-2–mediated sVEGFR-1 release. These results show that endothelial PAR-2 activation leading to increased sVEGFR-1 release may contribute to the maternal vascular dysfunction observed in preeclampsia and highlights the PAR-2 pathway as a potential therapeutic target for the treatment of preeclampsia.
Sensitivity of Atmospheric Motion Vectors Height Assignment Methods to Semitransparent Cloud Properties Using Simulated Meteosat-8 Radiances
Authors: Borde Régis , Dubuisson Philippe
Published: February 2010

This paper presents the sensitivity to various atmospheric parameters of two height assignment methods that aim to retrieve the cloud-top height of semitransparent clouds. The use of simulated Meteosat-8 radiances has the advantage that the pressure retrieved by a given method can be compared to the initial pressure set to the cloud in the model, which is exactly known. The methods retrieve the pressure of a perfectly opaque cloud to within a few hectopascals. However, considering more realistic ice clouds, methods are sensitive to all of the tested atmospheric parameters and, especially, to the cloud microphysics, which can bias the results of the CO2-slicing method by several tens of hectopascals. The cloud-top pressure retrieval is especially difficult for thinner clouds with optical thicknesses smaller than 2, for which the errors can reach several tens of hectopascals. The methods have also been tested after introducing realistic perturbations in the temperature and humidity profiles and on the clear-sky surface radiances. The corresponding averages of errors on the retrieved pressures are also very large, especially for thin clouds. In multilayer cloud situations the height assignment methods do not work properly, placing the cloud-top height somewhere between the two cloud layers for most cirrus cloud layers with optical thicknesses between 0.1 and 10.
Topographic Effects on the Surface Radiation Balance in and around Arizona’s Meteor Crater
Authors: Hoch Sebastian W. , Whiteman C. David
Published: February 2010

The individual components of the slope-parallel surface radiation balance were measured in and around Arizona’s Meteor Crater to investigate the effects of topography on the radiation balance. The crater basin has a diameter of 1.2 km and a depth of 170 m. The observations cover the crater floor, the crater rim, four sites on the inner sidewalls on an east–west transect, and two sites outside the crater. Interpretation of the role of topography on radiation differences among the sites on a representative clear day is facilitated by the unique symmetric crater topography. The shortwave radiation balance was affected by the topographic effects of terrain exposure, terrain shading, and terrain reflections, and by surface albedo variations. Terrain exposure caused a site on the steeper upper eastern sidewall of the crater to receive 6% more daily integrated shortwave energy than a site on the lower part of the same slope. Terrain shading had a larger effect on the lower slopes than on the upper slopes. At the lower western slope site the daily total was reduced by 6%. Measurements indicate a diffuse radiation enhancement due to sidewall reflections. The longwave radiation balance was affected by counterradiation from the crater sidewalls and by reduced emissions due to the formation of a nighttime temperature inversion. The total nighttime longwave energy loss at the crater floor was 72% of the loss observed at the crater rim.
Linking Observations of the Asian Monsoon to the Indian Ocean SST: Possible Roles of Indian Ocean Basin Mode and Dipole Mode
Authors: Yang Jianling , Liu Qinyu , Liu Zhengyu
Published: February 2010

The authors investigate the relationship between sea surface temperature (SST) in the tropical Indian Ocean (TIO) and the seasonal atmosphere circulation in the Asian monsoon region (AMR) using the maximum covariance analyses (MCAs). The results show that the Asian monsoon circulation is significantly correlated with two dominant SST anomaly (SSTA) modes: the Indian Ocean Basin mode (IOB) and the Indian Ocean dipole mode (IOD). The peak SSTA of the IOB appears in spring and has a much stronger relationship with the Asian summer monsoon than the peak of the IOD does, whereas the peak SSTA for the IOD appears in fall and shows a stronger link to the Asian winter monsoon than to the Asian summer monsoon. In addition, the IOB in spring has a relatively stronger link with the atmospheric circulation in summer than in other seasons.

The large-scale atmospheric circulation and SSTA patterns of the covariability of the first two dominant MCA modes are described. For the first MCA mode, a warm IOB, persists from spring to summer, and the atmospheric circulation is enhanced by the establishment of the climatological summer monsoon. The increased evaporative moisture associated with the warm IOB is transported to South Asia by the climatological summer monsoon, which increases the moisture convergence toward this region, leading to a significant increase in summer monsoon precipitation. For the second MCA mode, a positive IOD possibly corresponds to a weaker Indian winter monsoon and more precipitation over the southwestern and eastern equatorial TIO.
How Much Do Different Land Models Matter for Climate Simulation? Part II: A Decomposed View of the Land–Atmosphere Coupling Strength
Authors: Wei Jiangfeng , Dirmeyer Paul A. , Guo Zhichang
Published: February 2010

The Global Land–Atmosphere Coupling Experiment (GLACE) built a framework to estimate the strength of the land–atmosphere interaction across many weather and climate models. Within this framework, GLACE-type experiments are performed with a single atmospheric model coupled to three different land models. The precipitation time series is decomposed into three frequency bands to investigate the large-scale connection between external forcing, precipitation variability and predictability, and land–atmosphere coupling strength. It is found that coupling to different land models or prescribing subsurface soil moisture does not change the global pattern of precipitation predictability and variability too much. However, the regional impact of soil moisture can be highlighted by calculating the land–atmosphere coupling strength, which shows very different patterns for the three models. The estimated precipitation predictability and land–atmosphere coupling strength is mainly associated with the low-frequency component of precipitation (periods beyond 3 weeks). Based on these findings, the land–atmosphere coupling strength is conceptually decomposed into the impact of low-frequency external forcing and the impact of soil moisture. Because most models participating in GLACE have overestimated the low-frequency component of precipitation, a calibration to the GLACE-estimated land–atmosphere coupling strength is performed. The calibrated coupling strength is generally weaker, but the global pattern does not change much. This study provides an important clarification of land–atmosphere coupling strength and increases the understanding of the land–atmosphere interaction.
Air–Sea Fluxes over the Gulf Stream Region: Atmospheric Controls and Trends
Authors: Shaman Jeffrey , Samelson R. M. , Skyllingstad Eric
Published: February 2010

The intraseasonal variability of turbulent surface heat fluxes over the Gulf Stream extension and subtropical mode water regions of the North Atlantic, and long-term trends in these fluxes, are explored using NCEP–NCAR reanalysis. Wintertime sensible and latent heat fluxes from these surface waters are characterized by episodic high flux events due to cold air outbreaks from North America. Up to 60% of the November–March (NDJFM) total sensible heat flux and 45% of latent heat flux occurs on these high flux days. On average 41% (34%) of the total NDJFM sensible (latent) heat flux takes place during just 17% (20%) of the days. Over the last 60 years, seasonal NDJFM sensible and latent heat fluxes over the Climate Variability and Predictability (CLIVAR) Mode Water Dynamic Experiment (CLIMODE) region have increased owing to an increased number of high flux event days. The increased storm frequency has altered average wintertime temperature conditions in the region, producing colder surface air conditions over the North American eastern seaboard and Labrador Sea and warmer temperatures over the Sargasso Sea. These temperature changes have increased low-level vertical wind shear and baroclinicity along the North Atlantic storm track over the last 60 years and may further favor the trend of increasing storm frequency over the Gulf Stream extension and adjacent region.
Assessing the Response of Snow Avalanche Runout Altitudes to Climate Fluctuations Using Hierarchical Modeling: Application to 61 Winters of Data in France
Authors: Eckert N. , Baya H. , Deschatres M.
Published: February 2010

Snow avalanches are natural hazards strongly controlled by the mountain winter climate, but their recent response to climate change has thus far been poorly documented. In this paper, hierarchical modeling is used to obtain robust indexes of the annual fluctuations of runout altitudes. The proposed model includes a possible level shift, and distinguishes common large-scale signals in both mean- and high-magnitude events from the interannual variability. Application to the data available in France over the last 61 winters shows that the mean runout altitude is not different now than it was 60 yr ago, but that snow avalanches have been retreating since 1977. This trend is of particular note for high-magnitude events, which have seen their probability rates halved, a crucial result in terms of hazard assessment. Avalanche control measures, observation errors, and model limitations are insufficient explanations for these trends. On the other hand, strong similarities in the pattern of behavior of the proposed runout indexes and several climate datasets are shown, as well as a consistent evolution of the preferred flow regime. The proposed runout indexes may therefore be usable as indicators of climate change at high altitudes.
Role of the Gulf Stream and Kuroshio–Oyashio Systems in Large-Scale Atmosphere–Ocean Interaction: A Review
Authors: Kwon Young-Oh , Alexander Michael A. , Bond Nicholas A. , Frankignoul Claude , Nakamura Hisashi , Qiu Bo , Thompson Lu Anne
Published: February 2010

Ocean–atmosphere interaction over the Northern Hemisphere western boundary current (WBC) regions (i.e., the Gulf Stream, Kuroshio, Oyashio, and their extensions) is reviewed with an emphasis on their role in basin-scale climate variability. SST anomalies exhibit considerable variance on interannual to decadal time scales in these regions. Low-frequency SST variability is primarily driven by basin-scale wind stress curl variability via the oceanic Rossby wave adjustment of the gyre-scale circulation that modulates the latitude and strength of the WBC-related oceanic fronts. Rectification of the variability by mesoscale eddies, reemergence of the anomalies from the preceding winter, and tropical remote forcing also play important roles in driving and maintaining the low-frequency variability in these regions. In the Gulf Stream region, interaction with the deep western boundary current also likely influences the low-frequency variability. Surface heat fluxes damp the low-frequency SST anomalies over the WBC regions; thus, heat fluxes originate with heat anomalies in the ocean and have the potential to drive the overlying atmospheric circulation. While recent observational studies demonstrate a local atmospheric boundary layer response to WBC changes, the latter’s influence on the large-scale atmospheric circulation is still unclear. Nevertheless, heat and moisture fluxes from the WBCs into the atmosphere influence the mean state of the atmospheric circulation, including anchoring the latitude of the storm tracks to the WBCs. Furthermore, many climate models suggest that the large-scale atmospheric response to SST anomalies driven by ocean dynamics in WBC regions can be important in generating decadal climate variability. As a step toward bridging climate model results and observations, the degree of realism of the WBC in current climate model simulations is assessed. Finally, outstanding issues concerning ocean–atmosphere interaction in WBC regions and its impact on climate variability are discussed.
A Comparison of Methods for Determining Significant Wave Heights—Applied to a 3-m Discus Buoy during Hurricane Katrina
Authors: Bender L. C. , Guinasso N. L. , Walpert J. N. , Howden S. D.
Published: February 2010

In August 2005, the eye of Hurricane Katrina passed 90 km to the west of a 3-m discus buoy deployed in the Mississippi Sound and operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). The buoy motions were measured with a strapped-down, 6 degrees of freedom accelerometer, a three-axis magnetometer, and from the displacement of a GPS antenna measured by postprocessed-kinematic GPS. Recognizing that an accelerometer experiences a large offset due to gravity, the authors investigated four different means of computing wave heights. In the most widely used method for a buoy with a strapped-down, 1D accelerometer, wave heights are overestimated by 26% on average and up to 56% during the peak of the hurricane. In the second method, the component of gravity is removed from the deck relative z-axis accelerations, requiring pitch and roll information. This is most similar to the motion of the GPS antenna and reduces the overestimation to only 5% on average. In the third method, the orientation data are used to obtain a very accurate estimate of the vertical acceleration, reducing the overestimation of wave heights to 1%. The fourth method computes an estimate of the true earth-referenced vertical accelerations using the accelerations from all three axes but not the pitch and roll information. It underestimates the wave heights by 2.5%. The fifth method uses the acceleration from all three axes and the pitch and roll information to obtain the earth-referenced vertical acceleration of the buoy, the most accurate measure of the true wave vertical acceleration. The primary conclusion of this work is that the measured deck relative accelerations from a strapped-down, 1D accelerometer must be tilt corrected in environments of high wave heights.
Targeting Studies for the Extratropical Transition of Hurricane Fabian: Signal Propagation, the Interaction between Fabian and Midlatitude Flow, and an Observation Strategy
Authors: Chen Hua , Pan Weiyu
Published: February 2010

This study examines how the impact of targeted observations propagates during the extratropical transition (ET) of Hurricane Fabian. Signal (i.e., the forecast difference between denial experiments and the control experiment) propagation can reveal the interaction between the tropical cyclone (TC) and the midlatitude jet, and the energy dispersion or propagation of the TC undergoing ET also can be determined. The crucial role of an upper-level trough is discussed. Based on this study, a strategy issue regarding targeted observations of ET and several typical problems regarding the numerical prediction of ET are discussed.

The results show that the greatest signals along with their propagation are associated closely with various types of instabilities. In general, the signal first appears at the location of the TC, and then it propagates to the midlatitude jet through the interaction between the TC and the jet itself. Thereafter, signals propagate downstream along the jet and downward to the lower troposphere at the same time by way of Rossby wave packets; the jet essentially acts as a waveguide. Through the signal propagation and development in the jet, the impact of targeted observations seems sensitive to the ET process.

The interaction between the TC and the jet occurs as high θ (low potential vorticity) air flows out of the TC toward the northeast and into the jet below the tropopause. The interaction may be strengthened by an upstream trough at upper levels. The TC outflow enhances the potential vorticity (PV) gradient and baroclinity in the jet. Therefore, the jet becomes stronger and more baroclinically unstable. The signal propagation also indicates the energy dispersion of a TC undergoing ET.

The strong southwesterly flow ahead of the upper-level trough steers Fabian to higher latitudes, and strengthens the advection process of low PV air into the jet. Therefore, the development of the upper-level trough and its proximity to the TC are crucial for the interaction between the TC and the jet, and the resulting signal propagation. Small deviations from this synoptic situation may result in great differences in the signal propagation and the ET forecast. The most suitable region for targeting is likely a region where crucial synoptic processes can magnify initial errors.
Filamentation Time Diagnosis of Thinning Troughs and Cutoff Lows
Authors: Tsai Yu-Ming , Kuo Hung-Chi , Schubert Wayne H.
Published: February 2010

This paper analyzes synoptic-scale trough-thinning processes using a filamentation time diagnostic. The filamentation time diagnostic is derived from the potential vorticity equation expressed in spherical coordinates in the horizontal plane and the isentropic coordinate in the vertical direction. The diagnostic is an accurate measure of stirring processes under the condition of “slowly varying velocity gradients.” Trough-thinning processes are analyzed for one tropical example and two midlatitude examples. The results indicate that the filamentation time for the tropical trough-thinning event is generally longer than those for the midlatitude trough events. In addition to the effects of stretching and shearing deformation, the filamentation time diagnostic contains the effects of divergence. For the calculation of filamentation time on isentropic surfaces in spherical coordinates, it is acceptable to ignore the curvature effects in the tropics; however, in both the midlatitudes and the tropics, isentropic divergence effects should be retained for improved accuracy. Combining an analysis of cross potential vorticity contour flows on isentropic surfaces with the filamentation time analysis gives a more complete description of the dynamics. The results show that the filamentation time diagnostic can serve as a useful aid in the analysis and prediction of trough thinning and cutoff-low formation.
TIGGE: Comparison of the Prediction of Northern Hemisphere Extratropical Cyclones by Different Ensemble Prediction Systems
Authors: Froude Lizzie S. R.
Published: February 2010

The Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) is a World Weather Research Programme project. One of its main objectives is to enhance collaboration on the development of ensemble prediction between operational centers and universities by increasing the availability of ensemble prediction system (EPS) data for research. This study analyzes the prediction of Northern Hemisphere extratropical cyclones by nine different EPSs archived as part of the TIGGE project for the 6-month time period of 1 February 2008–31 July 2008, which included a sample of 774 cyclones. An objective feature tracking method has been used to identify and track the cyclones along the forecast trajectories. Forecast verification statistics have then been produced [using the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis as the truth] for cyclone position, intensity, and propagation speed, showing large differences between the different EPSs. The results show that the ECMWF ensemble mean and control have the highest level of skill for all cyclone properties. The Japanese Meteorological Administration (JMA), the National Centers for Environmental Prediction (NCEP), the Met Office (UKMO), and the Canadian Meteorological Centre (CMC) have 1 day less skill for the position of cyclones throughout the forecast range. The relative performance of the different EPSs remains the same for cyclone intensity except for NCEP, which has larger errors than for position. NCEP, the Centro de Previsão de Tempo e Estudos Climáticos (CPTEC), and the Australian Bureau of Meteorology (BoM) all have faster intensity error growth in the earlier part of the forecast. They are also very underdispersive and significantly underpredict intensities, perhaps due to the comparatively low spatial resolutions of these EPSs not being able to accurately model the tilted structure essential to cyclone growth and decay. There is very little difference between the levels of skill of the ensemble mean and control for cyclone position, but the ensemble mean provides an advantage over the control for all EPSs except CPTEC in cyclone intensity and there is an advantage for propagation speed for all EPSs. ECMWF and JMA have an excellent spread–skill relationship for cyclone position. The EPSs are all much more underdispersive for cyclone intensity and propagation speed than for position, with ECMWF and CMC performing best for intensity and CMC performing best for propagation speed. ECMWF is the only EPS to consistently overpredict cyclone intensity, although the bias is small. BoM, NCEP, UKMO, and CPTEC significantly underpredict intensity and, interestingly, all the EPSs underpredict the propagation speed, that is, the cyclones move too slowly on average in all EPSs.
High Achievement on Advanced Placement Exams: The Relationship of School-Level Contextual Factors to Performance
Authors: Burney Virginia H.
Published: February 2010

The purpose of the study was to identify school- and district-level variables that relate to advanced academic achievement, as defined by the ratio of number of scores of 3, 4, or 5 on Advanced Placement exams to school enrollment. The study initially included 46 variables for 339 public high schools in one Midwestern state. Hierarchical linear regressions were applied to 14 and then 7 independent variables, explaining 80% of the variance in advanced academic achievement among high schools. Findings indicate that after accounting for seemingly fixed factors, schools and districts can still contribute significantly in the development of advanced academic achievement. Implications for educators and policy makers are discussed.

Putting the Research to Use

The percentage of minority students, percentage receiving free and reduced lunch, and the educational level of the community are common reasons given for explaining the lack of high achievement or the lack of advanced opportunities for the high-ability students in their schools. However, this study found that these fixed contextual variables, in general, do not limit the school from having a group of high performers among its students. The focus needs to be on what academic services and opportunities can be provided for high-ability students that will increase their academic preparation and therefore likelihood of graduating from college. Access to advanced courses is a factor within the control of school policy makers. The question to consider, then, is how might small schools with minimal resources offer these advanced courses for their high-ability students. One promising solution is to offer the AP courses through virtual means.
Foaming Behavior and Cellular Structure of Microcellular HDPE Nanocomposites Prepared by a High Temperature Process
Authors: Khorasani Mohammad Mehdi , Ghaffarian Seyed Reza , Babaie Amir , Mohammadi Naser
Published: February 2010

This article discusses the development of microcellular HDPE and HDPE—clay nanocomposites via a batch high temperature process using supercritical N 2. The study incorporates the effects of clay content and nanocomposite microstructure on the foaming process performance and cellular morphology under investigation. It was possible to produce much nucleated and more expanded microcellular foams with the nanocomposites than with the pure HDPE, as over 14 vol% void fraction could be reached at 6 wt% clay containing nanocomposite as a good result for foaming by N2 gas via a batch foaming process. We found that the state of nanoparticle dispersion affects the microcellular morphology, so a better dispersed nanocomposite results in a more nucleated system in the microcellular foaming process. Moreover, the relationship between crystalline morphology and cell structure was investigated. Crystallinity and melting point were the important parameters for controlling the cell growth mechanism in this foaming method.
Financial Regulation and Commercial Protection: Should Policy Change?
Authors: Barrell Ray , Weale Martin
Published: February 2010

When protection is discussed people normally have policies designed to restrict imports in mind. But the way in which the international economy has been affected by toxic financial assets issued in the United States suggests that countries might face problems not only because of the goods and services trade but also because of the financial assets they import. Thus, in discussing the case for protection, we consider first whether there is a case for protection to prevent economies importing some types of financial instrument and, secondly, whether there is a case for more traditional protection as a way of resolving the global imbalances of the world economy. We conclude that financial protection is a sensible way for countries to protect themselves from risky assets if the production and testing of such assets is not regulated internationally.
Maturing Debt and Default Risks
Authors: Foley-Fisher Nathan
Published: February 2010

The old trend of ever smaller amounts of government debt maturing and being retired gracefully is passing. In its place, a boom in issuance as a consequence of the recent crisis will lead to a youthful increase in the amount of maturing debt that requires settlement. The UK has the advantage, relative to some other countries in the Euro Area, of being able to issue longer-term debt (see figure 1), which helps avoid the so-called ‘roll over’ risk associated with maturing debt. By contrast, the long period of surpluses run by the Spanish government caused them to obtain over 75 per cent of recent funding from short-term markets.
Managing Housing Bubbles in Regional Economies Under EMU: Ireland and Spain
Authors: Conefrey Thomas , Fitz Gerald John
Published: February 2010

With the advent of EMU, monetary policy can no longer be used to prevent housing market bubbles in regional economies such as Ireland or Spain. However, fiscal policy can and should be used to achieve the same effect. This paper shows that the advent of EMU relaxed existing financial constraints in Ireland and Spain, allowing a more rapid expansion of the housing stock in those countries to meet their specific demographic circumstances. However, the failure to prevent these booms turning into bubbles did lasting damage to the two economies, damage that could have been avoided by more appropriate fiscal policy action.
Effect of Proteasome Inhibitors With Different Chemical Structures on the Ubiquitin–Proteasome System In Vitro
Authors: Csizmadia V. , Csizmadia E. , Silverman L. , Simpson C. , Raczynski A. , O’Brien L. , Gallacher M. , Cardoza K. , Kadambi V. J. , Fedyk E. R. , Alden C. L.
Published: February 2010

Proteasome inhibitor therapeutics (PITs) have the potential to cause peripheral neuropathy. In a mouse model of PIT-induced peripheral neuropathy, the authors demonstrated that ubiquitin-positive multifocal protein aggregates with nuclear displacement appear in dorsal root ganglion cells of animals that subsequently develop nerve injuries. This peripheral-nerve effect in nonclinical models has generally been recognized as the correlate of grade 3 neuropathy in clinical testing. In differentiated PC12 cells, the authors demonstrated perturbations correlative with the development of neuropathy in vivo, including ubiquitinated protein aggregate (UPA) formation and/or nuclear displacement associated with the degree of proteasome inhibition. They compared 7 proteasome inhibitors of 3 chemical scaffolds (peptide boronate, peptide epoxyketone, and lactacystin analog) to determine if PIT-induced peripheral neuropathy is modulated by inhibition of the proteasome (ie, a mechanism-based effect) or due to effects independent of proteasome inhibition (ie, an off target or chemical-structure-based effect). The appearance of UPAs was assayed at IC90 ± 5% (90% inhibition concentration ± 5%) for 20S proteasome inhibition. Results show that each of the investigated proteasome inhibitors induced identical proteasome-inhibitor-specific ubiquitin-positive immunostaining and nuclear displacement in PC12 cells. Other agents—such as paclitaxel, cisplatin, and thalidomide, which cause neuropathy by other mechanisms—did not cause UPAs or nuclear displacement, demonstrating that the effect was specific to proteasome inhibitors. In conclusion, PIT-induced neuronal cell UPA formation and nuclear displacement are mechanism based and independent of the proteasome inhibitor scaffold. These data indicate that attempts to modulate the neuropathy associated with PIT may not benefit from changing scaffolds.
Unlocking the Closed Door: Arguments for Open Access Hospice
Authors: Furman Christian Davis , Doukas David John , Reichel William
Published: February 2010

The traditional view of standard hospice (SH) care is that once begun, the doorway toward curative and other forms of nonpalliative treatment is irrevocably locked. We will argue that such a traditional view needs to be reassessed in light of new arguments and data regarding access to these avenues of treatment. We will argue that patients should be supported in their transition from SH to open access hospice (OAH). Open access hospice should be available to all patients because of ethical arguments, patient satisfaction arguments, and costs of care arguments. More randomized controlled research trials need to be performed to study the impact of OAH versus SH. This research should focus on patient satisfaction, cost, and survival.
e-Health in Pediatric Palliative Care
Authors: Knapp Caprice
Published: February 2010

e-Health has the potential to improve pediatric palliative care. e-Health initiatives use the Internet or health information technology to improve quality of care and have the potential to decrease costs by reducing medical errors, reducing duplication of services, improving access to diagnostic and laboratory results, and improving communication between providers and patients, and so on. The majority of e-health initiatives are for adults and only a limited amount of evidence exists in the literature on e-health interventions in palliative care that are focused on pediatrics. To explore what role e-health could play in pediatric palliative care programs, this article aims to describe the Internet use in general in the United States and in palliative care, describe the use of health information technology in general in the United States and in palliative care, and suggest areas in pediatric palliative care that might benefit from e-health interventions.
Primary Progressive Aphasia: Clinical, Imaging, and Neuropathological Findings
Authors: Gliebus Gediminas
Published: February 2010

Primary Progressive Aphasia (PPA) is a neurodegenerative disorder initially presenting with progressive language imapirment. This article provides a clinically oriented review of PPA. Different clinical presentations and imaging findings of 3 subtypes, agrammatic, semantic and logopenic, are presented. Underlying neuropathology, medical and social management aspects of these patients are reviewed.