bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Survival of the Very Elderly Undergoing Aortic Valve Surgery
Authors: Likosky Donald S. , Sorensen Meredith J. , Dacey Lawrence J. , Baribeau Yvon R. , Leavitt Bruce J. , DiScipio Anthony W. , Hernandez Felix , Cochran Richard P. , Quinn Reed , Helm Robert E. , Charlesworth David C. , Clough Robert A. , Malenka David J. , Sisto Donato A. , Sardella Gerald , Olmstead Elaine M. , Ross Cathy S. , O'Connor Gerald T.
Published: September 2009

Background—

Increasing numbers of the very elderly are undergoing aortic valve procedures. We describe the short- and long-term survivorship for this cohort.

Methods and Results—

We conducted a cohort study of 7584 consecutive patients undergoing open aortic valve surgery without (51.1%; AVR) or with (48.9%; AVR + CABG) concomitant coronary artery bypass graft surgery between November 10, 1987 through June 30, 2006. Patient records were linked to the Social Security Administration’s Death Master File. Survivorship was stratified by age and concomitant CABG surgery. During 39 835 person-years of follow-up, there were 2877 deaths. Among AVR, there were 3304 patients <80 years of age, 419 patients 80 to 84 years, and 156 patients ≥85 years (24 patients >90 years). Among AVR+CABG patients, there were 2890 patients <80 years of age, 577 patients 80 to 84 years, and 238 patients ≥85 years (22 patients >90 years). Median survivorship for patients undergoing isolated AVR was 11.5 years (<80 years), 6.8 years (80 to 84 years), 6.2 years (≥85 years); for patients undergoing AVR+CABG, median survivorship was 9.4 years (<80 years), 6.8 years (80 to 84 years), and 7.1 years (≥85 years). Among both procedures, adjusted survivorship was significantly different across strata of age (
P
<0.001). These findings are similar to life expectancy of the general population from actuarial tables: 80 to 84 years (7 years) and ≥85 years (5 years).

Conclusions—

Survivorship among octogenarians is favorable, with more than half the patients surviving more than 6 years after their surgery. Concomitant CABG surgery does not diminish median survivorship among patients >80 years of age.
Donor Serum SMARCAL1 Concentrations Predict Primary Graft Dysfunction in Cardiac Transplantation
Authors: Aharinejad Seyedhossein , Andrukhova Olena , Gmeiner Matthias , Thomas Anita , Aliabadi Arezu , Zuckermann Andreas , Krenn Katharina , Grimm Michael
Published: September 2009

Background—

Primary graft dysfunction (PGD) is a life-threatening complication in cardiac transplantation. A sensitive, specific, and easily measurable predictor in donors could facilitate PGD prevention.

Methods and Results—

SMARCAL1 is a matrix-associated regulator of chromatin with helicase and ATPase activities, and its serum concentrations were significantly increased in a targeted protein array in donors whose grafts developed PGD. Therefore, this study analyzed SMARCAL1 serum concentrations by ELISA in 336 heart donors before and after aortic cross-clamping (ACC) and in recipients at 10, 30, and 60 minutes reperfusion. Demographic and hemodynamic parameters of donors and recipients as well as transplant procedure characteristics were documented. PGD (n=68) was defined as ventricular dilation and hypocontractility associated with systolic blood pressure <90 mm Hg, pulmonary capillary wedge pressure >20 mm Hg, and decreased mixed venous oxygen saturation necessitating mechanical circulatory support. SMARCAL1 serum protein concentration was significantly increased only before and after ACC in donors (
P
<0.0001) whose grafts developed PGD compared to those who did not. In receiver operating characteristic curve analysis, SMARCAL1 serum concentration at a cut-off level of ≥1.25 ng/mL before ACC in donors predicted PGD (
P
<0.0001, AUC=0.988, OR=17.050, 95% CI=5.200 to 55.901) with 96% sensitivity and 88% specificity. SMARCAL1 serum concentrations <1.25 ng/mL in donors before ACC resulted in 97% PGD-free outcome and SMARCAL1 concentrations ≥1.25 resulted in 83% PGD occurrence.

Conclusions—

Donor serum SMARCAL1 may serve as a specific, sensitive, and noninvasive predictive marker in the assessment of cardiac graft quality.
Autograft Reinforcement to Preserve Autograft Function After the Ross Procedure
Authors: Charitos Efstratios I. , Hanke Thorsten , Stierle Ulrich , Robinson Derek R. , Bogers Ad J.J.C. , Hemmer Wolfgang , Bechtel Matthias , Misfeld Martin , Gorski Armin , Boehm Juergen O. , Rein Joachim G. , Botha Cornelius A. , Lange Ruediger , Hoerer Juergen , Moritz Anton , Wahlers Thorsten , Franke Ulrich F.W. , Breuer Martin , Ferrari-Kuehne Katharina , Hetzer Roland , Huebler Michael , Ziemer Gerhard , Takkenberg Johanna J.M. , Sievers Hans H.
Published: September 2009

Background—

Autograft reinforcement interventions (R) during the Ross procedure are intended to preserve autograft function and improve durability. The aim of this study is to evaluate this hypothesis.

Methods and Results—

1335 adult patients (mean age:43.5±12.0 years) underwent a Ross procedure (subcoronary, SC, n=637; root replacement, Root, n=698). 592 patients received R of the annulus, sinotubular junction, or both. Regular clinical and echocardiographic follow-up was performed (mean:6.09±3.97, range:0.01 to 19.2 years). Longitudinal assessment of autograft function with time was performed using multilevel modeling techniques. The Root without R (Root−R) group was associated with a 6× increased reoperation rate compared to Root with R (Root+R), SC with R (SC+R), and without R (SC-R; 12.9% versus 2.3% versus 2.5%.versus 2.6%, respectively;
P
<0.001). SC and Root groups had similar rate of aortic regurgitation (AR) development over time. Root+R patients had no progression of AR, whereas Root−R had 6 times higher AR development compared to Root+R. In SC, R had no remarkable effect on the annual AR progression. The SC technique was associated with lower rates of autograft dilatation at all levels of the aortic root compared to the Root techniques. R did not influence autograft dilatation rates in the Root group.

Conclusions—

For the time period of the study surgical autograft stabilization techniques preserve autograft function and result in significantly lower reoperation rates. The nonreinforced Root was associated with significant adverse outcome. Therefore, surgical stabilization of the autograft is advisable to preserve long-term autograft function, especially in the Root Ross procedure.
Differential Effects of Mechanical and Biological Stimuli on Matrix Metalloproteinase Promoter Activation in the Thoracic Aorta
Authors: Ruddy Jean Marie , Jones Jeffrey A. , Stroud Robert E. , Mukherjee Rupak , Spinale Francis G. , Ikonomidis John S.
Published: September 2009

Background—The effect of multiple integrated stimuli on vascular wall expression of matrix metalloproteinases (MMPs) remains unknown. Accordingly, this study examined the influence of the vasoactive peptide angiotensin II (Ang II) on wall tension–induced promoter activation of MMP-2, MMP-9, and membrane type-1 MMP (MT1-MMP).

Methods and Results—Thoracic aortic rings harvested from transgenic reporter mice containing the MMP-2, MMP-9, or MT1-MMP promoter sequence fused to a reporter gene were subjected to 3 hours of wall tension at 70, 85, or 100 mm Hg, with or without 100 nM Ang II. Total RNA was harvested from the aortic rings, and reporter gene transcripts were quantified by quantitative real-time polymerase chain reaction to measure MMP promoter activity. MT1-MMP promoter activity was increased at both 85 and 100 mm Hg, compared with baseline tension of 70 mm Hg, whereas treatment with Ang II stimulated MT1-MMP promoter activity to the same degree at all tension levels (P<0.05). Elevated tension and Ang II displayed a potential synergistic enhancement of MMP-2 promoter activation at 85 and 100 mm Hg, whereas the same stimuli caused a decrease in MMP-9 promoter activity (P<0.05) at 100 mm Hg.

Conclusions—This study demonstrated that exposure to a relevant biological stimulus (Ang II) in the presence of elevated tension modulated MMP promoter activation. Furthermore, these data suggest that a mechanical-molecular set point exists for the induction of MMP promoter activation and that this set point can be adjusted up or down by a secondary biological stimulus. Together, these results may have significant clinical implications toward the regulation of hypertensive vascular remodeling.
Racial Disparity Persists After On-Pump and Off-Pump Coronary Artery Bypass Grafting
Authors: Cooper William A. , Thourani Vinod H. , Guyton Robert A. , Kilgo Patrick , Lattouf Omar M. , Chen Edward P. , Morris Cullen D. , Vega J. David , Vassiliades Thomas A. , Puskas John D.
Published: September 2009

Background—

Race has been shown to be an independent risk factor for operative mortality after coronary artery bypass grafting (CABG). This study sought to determine the extent to which race is a risk factor for adverse events, long-term mortality, and whether off-pump surgery (OPCAB) modifies that risk.

Methods and Results—

The Society of Thoracic Surgeons Adult Cardiac Database at Emory Healthcare affiliated hospitals was queried for all primary isolated CABG records from 1997 to 2007. A propensity score was formulated to balance the patient groups with respect to treatment assignment (OPCAB or CABG on cardiopulmonary bypass). Multivariable logistic regression was used to assess the impact of black race and OPCAB on in-hospital outcomes (death, stroke, myocardial infarction, and their composite, major adverse cardiac events). Cox proportional hazards regression model and Kaplan–Meier curves determined whether black race affected long-term all-cause mortality. Interaction terms were constructed to test whether OPCAB surgery influences surgical results differently in black patients than in white patients. There were 12 874 consecutive CABG patients, including 2033 (15.8%) blacks and 10 841 (84.2%) whites. Survival at 3, 5, and 10 years for blacks (87.5%, 81.4%, 63.8%) was significantly lower than for whites (90.7%, 85.2%, 67.1%,
P
<0.001). Blacks (adjusted odds ratio, 0.77; 95% CI, 0.44 to 1.36) and whites (adjusted odds ratio, 0.72; 95% CI, 0.53 to 0.99) who had OPCAB had lower risk-adjusted odds of major adverse cardiac events than their racial counterparts who had CABG on cardiopulmonary bypass.

Conclusions—

Short- and long-term outcomes are significantly worse in black than in white patients undergoing primary isolated CABG. OPCAB does not narrow the disparity in outcomes between blacks and whites.
Mitral Repair versus Replacement for Ischemic Mitral Regurgitation
Authors: Magne Julien , Girerd Nicolas , Sénéchal Mario , Mathieu Patrick , Dagenais François , Dumesnil Jean G. , Charbonneau Éric , Voisine Pierre , Pibarot Philippe
Published: September 2009

Background—

When compared to mitral valve replacement (MVR), mitral valve repair (MVRp) is associated with better survival in patients with organic mitral regurgitation (MR). However, there is an important controversy about the type of surgical treatment that should be used in patients with ischemic MR. The objective of this study was to compare the postoperative outcome of MVRp versus MVR in patients with ischemic MR.

Methods and Results—

Preoperative and operative data of 370 patients with ischemic MR who underwent mitral valve surgery were prospectively collected and retrospectively analyzed. MVRp was performed in 50% of patients (n=186) and MVR in 50% (n=184). Although operative mortality was significantly lower after MVRp compared to MVR (9.7% versus 17.4%;
P
=0.03), overall 6-year survival was not statistically different between procedures (73±4% versus 67±4%;
P
=0.17). After adjusting for other risk factors and propensity score, the type of procedure (MVRp versus MVR) did not come out as an independent predictor of either operative (OR, 1.5; 95% CI, 0.7–2.9;
P
=0.34) or overall mortality (HR, 1.2; 95% CI, 0.7–1.9;
P
=0.52).

Conclusion—

As opposed to what has been reported in patients with organic MR, the results of this study suggest that MVRp is not superior to MVR with regard to operative and overall mortality in patients with ischemic MR. These findings provide support for the realization of a randomized trial comparing these 2 treatment modalities.
Ranolazine as a Cardioplegia Additive Improves Recovery of Diastolic Function in Isolated Rat Hearts
Authors: Hwang Hyosook , Arcidi Joseph M. , Hale Sharon L. , Simkhovich Boris Z. , Belardinelli Luiz , Dhalla Arvinder K. , Shryock John C. , Kloner Robert A.
Published: September 2009

Background—

Ranolazine (Ran), an antianginal agent, inhibits late Na
+
current. The purpose of this study was to determine whether there was an added benefit of adding Ran to cardioplegia (CP) in a model of global ischemia/reperfusion.

Methods and Results—

Isolated rat hearts were Langendorff-perfused and exposed to 40-minute normothermic, cardioplegic global ischemia and 30 minutes of reperfusion. Before ischemia and during reperfusion, hearts were treated with no drug (control) or with the late Na
+
current inhibitors Ran (5 μmol/L) or tetrodotoxin (1 μmol/L). Ischemic cardioplegic arrest led to an increase of left ventricular end-diastolic pressure (LVEDP) by ≥20 mm Hg (ie, cardiac contracture). Ten out of 11 hearts treated with CP alone developed contracture, whereas 6 out of 11 hearts treated with CP plus Ran developed contracture. Ran added to CP reduced LVEDP at the end of ischemia from 41±5 mm Hg in CP alone to 26±3 mm Hg in CP plus Ran (
P
=0.024). Area under the curve for LVEDP during the entire ischemic period was also smaller in CP plus Ran versus CP alone. The percent increase (from baseline) of LVEDP measured at the end of 30-minute reperfusion was smaller for CP plus Ran (66±18%) versus CP alone (287±90%;
P
=0.035). The area under the curve for LVEDP during reperfusion was smaller in CP plus Ran versus CP alone. Tetrodotoxin (1 μmol/L) also reduced cardiac contracture during ischemia/reperfusion, compared to CP alone.

Conclusions—

Our results suggest that Ran may have therapeutic potential as an adjunct to CP and further support a protective role of Na
+
current inhibition during ischemia/reperfusion.
The Complete Supraannular Concept
Authors: Ruzicka Daniel J. , Hettich Ina , Hutter Andrea , Bleiziffer Sabine , Badiu Catalin C. , Bauernschmitt Robert , Lange Ruediger , Eichinger Walter B.
Published: September 2009

Background—

Complete supraannular placement of an aortic bioprosthesis is one approach to optimize the hemodynamic result of an aortic valve replacement. It is achieved with the combination of a special valve design and the supraannular sewing technique with noneverted mattress sutures. We evaluated 5 bioprostheses designed for complete supraannular placement to assess potential hemodynamic differences caused by factors (eg, valve material) other than implantation position.

Methods and Results—

In 336 patients (mean age, 72.0±7.1 years; 143 women), hemodynamics including mean pressure gradients, effective orifice areas, and indices and incidence of patient-prosthesis mismatch were evaluated 6 months after surgery. Annulus diameter was measured during surgery. Patients received the Carpentier Edwards Perimount Magna (Magna, n=169), the Medtronic Mosaic (Mosaic, n=46), the Mosaic Ultra (Ultra, n=17), the SJM Epic Supra (Epic, n=46), and the Sorin Soprano (Soprano, n=58). For small annulus sizes (<23 mm), the mean pressure gradients of the Magna (11.82±4.8 mm Hg) were significantly lower than the Mosaic (16.04±6.1 mm Hg) and the Ultra (22.0±4.1 mm Hg), and the Soprano (13.3±5.2 mm Hg) was hemodynamically superior to the Ultra. For medium (23 to 24 mm) and large (>24 mm) annulus sizes, the mean pressure gradients of the Magna were lower than the Epic (10.0±3.5 mm Hg versus 14.9±6.4 mm Hg; 9.9±4.0 mm Hg versus 18.6±12.7 mm Hg). Furthermore, in patients with large annulus size, the mean pressure gradients of the Soprano (11.4±3.8 mm Hg) were lower compared with the Epic (18.5±12.7 mm Hg). Severe patient-prosthesis mismatch was observed more frequently in patients with the Mosaic (12/46; 26.1%) and the Ultra (3/17; 17.6%) prostheses.

Conclusions—

Complete supraannular placement cannot prevent high pressure gradients or patient-prosthesis mismatch thoroughly, but the choice of a bovine prosthesis can optimize hemodynamic performance.
Paclitaxel-Eluting Biodegradable Synthetic Vascular Prostheses
Authors: Innocente Francesco , Mandracchia Delia , Pektok Erman , Nottelet Benjamin , Tille Jean-Christophe , de Valence Sarra , Faggian Giuseppe , Mazzucco Alessandro , Kalangos Afksendiyos , Gurny Robert , Moeller Michael , Walpoth Beat H.
Published: September 2009

Background—

Clinical small-caliber vascular prostheses are unsatisfactory. Reasons for failure are early thrombosis and late intimal hyperplasia. We thus prepared biodegradable small-caliber vascular prostheses using electrospun polycaprolactone (PCL) with slow-releasing paclitaxel (PTX), an antiproliferative drug.

Methods and Results—

PCL solutions containing PTX were used to prepare nonwoven nanofibre-based 2-mm ID prostheses. Mechanical morphological properties and drug loading, distribution, and release were studied in vitro. Infrarenal abdominal aortic replacement was carried out with nondrug-loaded and drug-loaded prostheses in 18 rats and followed for 6 months. Patency, stenosis, tissue reaction, and drug effect on endothelialization, vascular remodeling, and neointima formation were studied in vivo. In vitro prostheses showed controlled morphology mimicking extracellular matrix with mechanical properties similar to those of native vessels. PTX-loaded grafts with suitable mechanical properties and controlled drug-release were obtained by factorial design. In vivo, both groups showed 100% patency, no stenosis, and no aneurysmal dilatation. Endothelial coverage and cell ingrowth were significantly reduced at 3 weeks and delayed at 12 and 24 weeks in PTX grafts, but as envisioned, neointima formation was significantly reduced in these grafts at 12 weeks and delayed at 6 months.

Conclusions—

Biodegradable, electrospun, nanofibre, polycaprolactone prostheses are promising because in vitro they maintain their mechanical properties (regardless of PTX loading), and in vivo show good patency, reendothelialize, and remodel with autologous cells. PTX loading delays endothelialization and cellular ingrowth. Conversely, it reduces neointima formation until the end point of our study and thus may be an interesting option for small caliber vascular grafts.
A Climatological Comparison of Radar and Ground Observations of Hail in Finland
Authors: Saltikoff Elena , Tuovinen Jari-Petteri , Kotro Janne , Kuitunen Timo , Hohti Harri
Published: September 2009

Two approaches to producing a hail climatology for Finland are compared. The first approach is based on 70 yr of hail reports from different sources (newspapers, storm spotters, and other volunteers). The second is derived primarily from radar data. It is shown that a selection of newspaper articles of hail damage covering a period of 70 yr provides a good overview of the typical monthly and diurnal distribution of hail occurrence over the country. Radar data covering five summers (2001–05) provide another data source, but with different potential sources of errors. The two distinct methods compared in this paper give roughly the same results in describing the hail climatology of Finland, which gives additional confidence in each of the methods. On the basis of both methods, most hailstones are observed in the afternoon, 1400–1600 local time. The hail “season” extends from May to early September with maximum occurrences in June, July, and August. This means that hail is most frequently observed when the convective energy available for storm growth is at its diurnal or seasonal peak. The length of the hail season is the same according to both radar and newspaper data. The main difference emerges in relation to July and August events: 37% of news about hail events is published in newspapers in late July but only 8% in early August, whereas for radar data the numbers are more evenly distributed, 33% and 18%, respectively. This can be partially explained by sociological factors—July is the main holiday month in Finland, when outdoor activities in more remote areas are more popular.
Objective Satellite-Based Detection of Overshooting Tops Using Infrared Window Channel Brightness Temperature Gradients
Authors: Bedka Kristopher , Brunner Jason , Dworak Richard , Feltz Wayne , Otkin Jason , Greenwald Thomas
Published: September 2009

Deep convective storms with overshooting tops (OTs) are capable of producing hazardous weather conditions such as aviation turbulence, frequent lightning, heavy rainfall, large hail, damaging wind, and tornadoes. This paper presents a new objective infrared-only satellite OT detection method called infrared window (IRW)-texture. This method uses a combination of 1) infrared window channel brightness temperature (BT) gradients, 2) an NWP tropopause temperature forecast, and 3) OT size and BT criteria defined through analysis of 450 thunderstorm events within 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Very High Resolution Radiometer (AVHRR) imagery. Qualitative validation of the IRW-texture and the well-documented water vapor (WV) minus IRW BT difference (BTD) technique is performed using visible channel imagery, CloudSat Cloud Profiling Radar, and/or Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) cloud-top height for selected cases. Quantitative validation of these two techniques is obtained though comparison with OT detections from synthetic satellite imagery derived from a cloud-resolving NWP simulation. The results show that the IRW-texture method false-alarm rate ranges from 4.2% to 38.8%, depending upon the magnitude of the overshooting and algorithm quality control settings. The results also show that this method offers a significant improvement over the WV-IRW BTD technique. A 5-yr Geosynchronous Operational Environmental Satellite (GOES)-12 OT climatology shows that OTs occur frequently over the Gulf Stream and Great Plains during the nighttime hours, which underscores the importance of using a day/night infrared-only detection algorithm. GOES-12 OT detections are compared with objective Eddy Dissipation Rate Turbulence and National Lightning Detection Network observations to show the strong relationship among OTs, aviation turbulence, and cloud-to-ground lightning activity.
A Hybrid Bulk–Bin Approach to Model Warm-Rain Processes
Authors: Grabowski Wojciech W. , Thouron Odile , Pinty Jean-Pierre , Brenguier Jean-Louis
Published: September 2009

This paper presents a hybrid approach to model warm-rain processes, merging the diverse schemes of bulk and detailed (bin) microphysics. In the bulk scheme, the key assumption is that the exact saturation is maintained inside a cloud. In contrast, the supersaturation inside a cloud is predicted in the bin scheme and is applied to calculate the diffusional growth of cloud droplets. Predicting the supersaturation is numerically cumbersome, however, and typically requires spatial and temporal resolutions that are significantly higher than those that can be applied in the bulk scheme. At the same time, supersaturations inside clouds are small, and the condensate amounts in bulk and bin schemes differ insignificantly. This critical observation forms a starting point for the hybrid bulk–bin approach. In this approach, when the cloud water first appears, the activation scheme inserts cloud droplets at the low end of the bin representation. Subsequent diffusional and eventually accretional growth shift the spectrum toward larger sizes so that the saturation inside a cloud is maintained. Details of the hybrid approach are discussed in this paper, and the validation against the traditional bin scheme in a framework of the adiabatic rising parcel is presented.

Before the scheme can be applied to the multidimensional cloud model, a 1D advection–condensation problem of Grabowski and Smolarkiewicz is used to address the issue of the numerical difficulties that finite-difference schemes experience near cloud edges. In the bulk case, these are in the form of condensation rate overshoots and undershoots; and this aspect requires special attention in the hybrid scheme. A novel approach is developed that provides a physically consistent solution near cloud edges using the hybrid bulk–bin scheme. The key is to allow grid boxes near the edges to be partly cloudy and to include spectral changes of cloud droplets that take this into account. Application of the hybrid scheme to an idealized 2D problem of moist thermal rising from rest and producing rain illustrates the application of the scheme to practical problems of cloud dynamics and warm-rain microphysics.
Do Undiluted Convective Plumes Exist in the Upper Tropical Troposphere?
Authors: Romps David M. , Kuang Zhiming
Published: September 2009

Using a passive tracer, entrainment is studied in cloud-resolving simulations of deep convection in radiative–convective equilibrium. It is found that the convective flux of undiluted parcels decays with height exponentially, indicating a constant probability per vertical distance of mixing with environmental air. This probability per distance is sufficiently large that undiluted updrafts are negligible above a height of 4–5 km and virtually absent above 10 km. These results are shown to be independent of the horizontal grid size within the range of 3.2 km to 100 m. Plumes that do reach the tropopause are found to be highly diluted.

An equivalent potential temperature is defined that is exactly conserved for all reversible adiabatic transformations, including those with ice. Using this conserved variable, it is shown that the latent heat of fusion (from both freezing and deposition) causes only a small increase in the level of neutral buoyancy near the tropopause. In fact, when taken to sufficiently low pressures, a parcel with an ice phase ends up colder than it would without an ice phase. Nevertheless, the contribution from fusion to a parcel’s kinetic energy is quite large.

Using an ensemble of tracers, information is encoded in parcels at the cloud base and decoded where the parcel is observed in the free troposphere. Using this technique, clouds at the tropopause are diagnosed for their cloud-base temperature, specific humidity, and vertical velocity. Using these as the initial values for a Lagrangian parcel model, it is shown that fusion provides the kinetic energy required for diluted parcels to reach the tropopause.
Increasing Trend of Synoptic Activity and Its Relationship with Extreme Rain Events over Central India
Authors: Ajayamohan R. S. , Merryfield William J. , Kharin Viatcheslav V.
Published: September 2009

The nature of the increasing frequency of extreme rainfall events (ERE) in central India is investigated by relating their occurrence to synoptic activity. Using a long record of the paths and intensities of monsoon synoptic disturbances, a synoptic activity index (SAI) is defined whose interannual variation correlates strongly with that in the number of ERE, demonstrating a strong connection between these phenomena. SAI furthermore shows a rising trend that is statistically indistinguishable from that in ERE, indicating that the increasing frequency of ERE is likely attributable to a rising trend in synoptic activity. This synoptic activity increase results from a rising trend in relatively weak low pressure systems (LPS), and it outweighs a declining trend in stronger LPS.
Dynamic Enthalpy, Conservative Temperature, and the Seawater Boussinesq Approximation
Authors: Young William R.
Published: September 2009

A new seawater Boussinesq system is introduced, and it is shown that this approximation to the equations of motion of a compressible binary solution has an energy conservation law that is a consistent approximation to the Bernoulli equation of the full system. The seawater Boussinesq approximation simplifies the mass conservation equation to ∇ · u = 0, employs the nonlinear equation of state of seawater to obtain the buoyancy force, and uses the conservative temperature introduced by McDougall as a thermal variable. The conserved energy consists of the kinetic energy plus the Boussinesq dynamic enthalpy h‡, which is the integral of the buoyancy with respect to geopotential height Z at a fixed conservative temperature and salinity. In the Boussinesq approximation, the full specific enthalpy h is the sum of four terms: McDougall’s potential enthalpy, minus the geopotential g0Z, plus the Boussinesq dynamic enthalpy h‡, and plus the dynamic pressure. The seawater Boussinesq approximation removes the large and dynamically inert contributions to h, and it reveals the important conversions between kinetic energy and h‡.
Predictability of the Performance of an Ensemble Forecast System: Predictability of the Space of Uncertainties
Authors: Satterfield Elizabeth , Szunyogh Istvan
Published: September 2009

The performance of an ensemble prediction system is inherently flow dependent. This paper investigates the flow dependence of the ensemble performance with the help of linear diagnostics applied to the ensemble perturbations in a small local neighborhood of each model gridpoint location ℓ. A local error covariance matrix 𝗣ℓ is defined for each local region, and the diagnostics are applied to the linear space defined by the range of the ensemble-based estimate of 𝗣ℓ. The particular diagnostics are chosen to help investigate the efficiency of in capturing the space of analysis and forecast uncertainties.

Numerical experiments are carried out with an implementation of the local ensemble transform Kalman filter (LETKF) data assimilation system on a reduced-resolution [T62 and 28 vertical levels (T62L28)] version of the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS). Both simulated observations under the perfect model scenario and observations of the real atmosphere in a realistic setting are used in these experiments. It is found that (i) paradoxically, the linear space provides an increasingly better estimate of the space of forecast uncertainties as the time evolution of the ensemble perturbations becomes more nonlinear with increasing forecast time; (ii) provides a more reliable linear representation of the space of forecast uncertainties for cases of more rapid error growth (i.e., for cases of lower predictability); and (iii) the ensemble dimension (E dimension) is a reliable predictor of the performance of in predicting the space of forecast uncertainties.
Rethinking Engineering Design and Decision Making in Response to Economic, Social, and Environmental Crises
Authors: Vanderburg Willem H.
Published: September 2009

High levels of specialization have created knowledge with little or no “peripheral vision,” and the resulting “blind spots” are causing many “collisions” with human life, society, and the biosphere. Each discipline and specialty must be equipped with a “map” showing its connections to everything else, but especially the negative consequences that tend to be associated with its practices. Preventively oriented practices can improve the ratio of desired to undesired effects of design and decision making to create ways of life that are more sustainable across the board, as opposed to treating symptoms (such as global warming). This new approach has already fired the imagination of many students in engineering.
Sydney Tar Ponds Remediation
Authors: Liu Fan , Bryson Ken A.
Published: September 2009

The infamous “Sydney Tar Ponds” are well known as one of the largest toxic waste sites of Canada, due to almost 100 years of steelmaking in Sydney, a once beautiful and peaceful city located on the east side of Cape Breton Island, Nova Scotia. This article begins with a contextual overview of the Tar Ponds issue including a brief introduction and history and summaries of the effects on the earth, the people, and the biotic community (animals and vegetation). Then the authors talk about the STS analysis approach, namely, a discussion of six systems to indicate what has been brought to the earth and mankind by technology and modern industry. The remaining part of the article describes the difficulties confronting China, some of which are similar to the ones Canada faces as a result of the Tar Ponds contamination, and summarizes some of the experiences at Tar Ponds and the lessons China can learn from Tar Ponds.
Feeling Blue in the South Valley
Authors: Mohr Beth A.
Published: September 2009

This article examines, by way of a case study, a community where groundwater has been highly contaminated with nitrate and how that situation brings together matters of public policy, environmental justice, and emerging technology. The Mountain View community lies in an unincorporated area of Bernalillo County, New Mexico; the neighborhood is 77% Hispanic and is a pocket of poverty whose residents are considered at risk for environmental injustice. Groundwater nitrate contamination was discovered in the 1960s, but residents were merely encouraged to dig deeper wells, until 1984 when most residents were put on nearby municipal water after a child was poisoned and hospitalized with methemoglobinemia, known as blue baby syndrome. In situ biodenitrification is an emerging technology that has been shown to completely remediate groundwater nitrate contamination after the injection of a food source for naturally occurring denitrifying bacteria; this technology is being considered for use in Mountain View.
The Nature of the Beast and the Beast in Nature
Authors: Ruth Matthias
Published: September 2009

This article traces conceptualizations of technology from narrow definitions to a broader understanding that encompasses the larger social and environmental context within which technology operates. In doing so, the associated social and environmental drivers and impacts of technology are identified and conclusions are drawn for the roles of technology and technology change in achieving sustainability.
Meeting the “Now” Need: PMH-APRN— Interpreter Teams Provide In-Home Mental Health Intervention for Depressed Latina Mothers With Limited English Proficiency
Authors: Beeber Linda S. , Lewis Virginia S. , Cooper Carolyn , Maxwell Lauren , Sandelowski Margarete
Published: September 2009

Latina mothers of infants and toddlers are at high risk for developing serious depressive symptoms if they are newly immigrated and have limited English proficiency (LEP). Depressive symptoms compromise these mothers and result in severe consequences for their U.S.-born children. A randomized clinical trial of a short-term, in-home psychotherapy intervention for symptomatic mothers in an area of the United States where bilingual mental health providers were scarce used teams of English-speaking advanced practice psychiatric mental health nurses and bilingual community interpreters who were trained in a conduit, consecutive model of interpretation. The article describes the development of a theoretically congruent interpreter model, the training program that supported it, the challenges that surfaced and lessons learned during successful implementation in the field. Future refinements in progress and uses of the model are discussed.
3D integral equation modeling with a linear dependence on dimensions
Authors: Avdeev Dmitry , Knizhnik Sergei
Published: September 2009

We have improved the integral equation method for modeling 3D electromagnetic fields by using the separability of its inherent [Formula: see text] dyadic Green’s tensors. Conventional integral equation approaches exhibit a quadratic dependence on model size, at least for the vertical dimension. In contrast, our approach has a linear dependence on all three dimensions. We tested our method on an example of induction logging in deviated boreholes.
3D finite-difference frequency-domain modeling of controlled-source electromagnetic data: Direct solution and optimization for high accuracy
Authors: Streich Rita
Published: September 2009

Three-dimensional modeling of marine controlled-source electromagnetic (CSEM) data is vital to improve the understanding of electromagnetic (EM) responses collected in increasingly complex geologic settings. A modeling tool for simulating 3D marine CSEM surveys, based on a finite-difference discretization of the Helmholtz equation for the electric fields, has been developed. Optimizations for CSEM simulations include the use of a frequency-domain technique, a staggering scheme that reduces inaccuracies especially for horizontal electric-dipole sources located near the seafloor, and a new interpolation technique that provides highly accurate EM field values for receivers located in the immediate vicinity of the seafloor. Source singularities are eliminated through a secondary-field approach, in which the primary fields are computed analytically for a homogeneous or a 1D layered background; the secondary fields are computed using the finite-difference technique. Exploiting recent advances in computer technology and algorithmic developments, the system of finite-difference equations is solved using the MUMPS direct-matrix solver. In combination with the other optimizations, this allows accurate EM field computations for moderately sized models on small computer clusters. The explicit availability of matrix factorizations is advantageous for multisource modeling and makes the algorithm well suited for future use within an inversion scheme. Comparisons of simulated data for (1) 1D models to data generated using a 1D reflectivity technique and (2) 3D models to published 3D data demonstrate the accuracy and benefits of the approach.
Synthesis and Transport Activities of HIV–Tat Peptide-modified Cholesterol Pullulan
Authors: Kimura Aki , Kamo Yosuke , Takashima Yuuki , Kanazawa Takanori , Okada Hiroaki , Fukuda Tsunehiko
Published: September 2009

A complex in which the cell-penetrating peptide HIV–Tat and cholesterol pullulan were conjugated through a disulfide bond was synthesized. The complex showed marked cell penetrating activities as a vector.
Speed-up of Ab Initio Hybrid Monte Carlo and Ab Initio Path Integral Hybrid Monte Carlo Simulations by Using an Auxiliary Potential Energy Surface
Authors: Nakayama Akira , Taketsugu Tetsuya , Shiga Motoyuki
Published: September 2009

Efficiency of the ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo methods is enhanced by employing an auxiliary potential energy surface that is used to update the system configuration via molecular dynamics scheme. As a simple illustration of this method, a dual-level approach is introduced where potential energy gradients are evaluated by computationally less expensive ab initio electronic structure methods.
Cytotoxic Evaluation of Ag@TiO2 Core–Shell Composite Nanoclusters against Cancer Cells
Authors: Abdulla-Al-Mamun Md , Kusumoto Yoshihumi , Islam Md Shariful
Published: September 2009

A Ag metal core–TiO2 shell (Ag@TiO2) composite nanocluster photocatalyst with uniform size and shape was successfully synthesized by a new simple citrate reduction method. The cytotoxicity of colloidal Ag@TiO2 composite nanoclusters was evaluated against cancer (HeLa) cells under UV–vis irradiation. Ag@TiO2 composite nanoclusters were characterized by using UV–vis absorption spectroscopy, TEM, SEM, XPS, XRD, and EDX techniques. It was found that Ag@TiO2 nanoclusters at low concentrations kill HeLa cells by 100%, whereas TiO2 nanoparticles alone kill only ca. 30% at the same concentrations.
Unusual Shapes of C60 Crystals Formed at Liquid–Liquid Interfaces
Authors: Yan Hu , Kagata Tsubasa , Uchida Takuya , Uematsu Takayuki , Iriyama Yu , Okuzaki Hidenori
Published: September 2009

We have found some unusually shaped C60 crystals which formed at liquid–liquid interfaces when m-xylene and ethanol were used as good and poor solvents, respectively. The crystals coexisted with large amounts of needle-like or whisker-like crystals which likely form at the initial stage of mixing the two solvents, probably indicating that this system follows Ostwald rule of stages like well-studied isoxazolone dye which has two polymorphs, i.e., the least stable needle-like one with a small size and the most stable rhombic crystal with a large size.
Obesity and health‐related quality of life: Does social support moderate existing associations?
Authors: Wiczinski Eileen , Döring Angela , John Jürgen , von Lengerke Thomas ,   For the KORA Study Group
Published: September 2009

Objectives Obesity has been shown to be negatively related to physical health‐related quality of life (HQOL) much more strongly than mental HQOL. This is remarkable given findings on obesity‐related social stigmata and associations with depression. Considering obesity as a stressor, this study tests for a moderating role of social support for obesity/HQOL associations among women and men.

Design Data come from N=2,732 participants aged 35–74 years in a 2004–2005 general population survey in the Augsburg region, Germany.

Methods Body weight and height were assessed by anthropometric measurements (classified by body mass index using WHO standards), social support by the Social Support Questionnaire 14‐item Short‐Form (F‐SozU‐K14) and HQOL by the 12‐item Short‐Form Health Survey (SF‐12). In multiple regression and general linear models, age, education, family status, health insurance, and place of residence were adjusted for.

Results Among both genders, obesity was associated with reduced physical but not mental HQOL. Among men reporting strong social support, physical HQOL was impaired neither in the moderately nor the severely obese group (compared with normal weight), while it was given less social support. Among women, poor physical HQOL was associated with obesity regardless of social support.

Conclusions In this adult population sample, no association was found for obesity with mental HQOL. In contrast, a negative association with physical HQOL exists for all subgroups except men with strong social support, indicating that social support buffers obesity‐related impairments in physical HQOL in men but not in women. This suggests that obese women and men with strong social support represent distinct populations, with possible implications for obesity care.
Stress-Strain-Time Relations for Idealized Materials
Authors: Lazan BJ
Published: September 2009

The following topics are covered: Role of micromechanistic, macroanalytical, and ad hoc testing approaches in rheological studies, and limitations of each. Concept of idealized materials and their rheological properties, equations of state, and constitutive equations. Review of thermodynamic equations of state for idealized gases. Viewpoints on explicit constitutive equations for defining macrorheological properties of solid materials and their limitations, considering localized and stress-history effects. Differential equations for defining constitutive relations and their corresponding mechanical models. Linear models, localized deformation, flow, and relaxation effects. Relation of experimental time scale to relaxation times (internal time scale) of materials in interpreting rheological observations. Role of nonlinear models. Limitation of idealized representations as an engineering tool for property studies on real materials.
A Review of the Stress-Strain-Time-Temperature Behavior of Ceramics
Authors: Kingery WD
Published: September 2009

Ceramic materials consist of mixtures of crystalline and vitreous components and usually include some porosity. As a result, no simple broad generalizations apply to all these materials. A review of their properties is based on the behavior of crystals, glasses, and complex mixtures. At room temperature, engineering ceramics are elastic solids and fail by brittle fracture; static fatigue (a time-dependent failure) is commonly observed. At high temperatures, time-dependent properties become increasingly important for both deformation and fracture behavior.
Stress-Strain-Time-Temperature Relations in Metallic Materials
Authors: Smith GV
Published: September 2009

In the introductory paper of this symposium, Lazan categorizes the possible approaches to the rheological behavior of materials as micromechanistic, macroanalytical, and ad hoc testing. The present paper considers the first two of these three approaches, with reference to the behavior of metals. Particular emphasis is placed on the micromechanistic approach, for although the phenomenological approach has both current value and future potential for engineering purposes, it has become increasingly clear that the processes involved in the inelastic flow of materials are both numerous and complex, and that ultimate understanding will only be achieved as an understanding of the micromechanisms is gained. At the same time it must be recognized that in spite of the long history of experimental and theoretical study, it is only in recent years that much of an insight has been gained into the micromechanisms of the flow of metals and only for the simpler situations—for example, in relatively pure metals. Consequently, for the present, and in fact probably for a long time into the future, the engineer will need to rely on phenomenological correlations.
Creep and Recovery of A Zirconium-Tin-Columbium Alloy
Authors: Lubahn JD
Published: September 2009

The creep characteristics of a 2Sn-2Cb zirconium alloy are expressed as a function of impurity content, heat treatment, and testing temperature, and the effects of these variables are described.

At the lower testing temperatures the creep behavior at constant stress and temperature conforms to the simple equation: ε=Bta where ε is creep strain, t is time, and B and a are constants. At higher temperatures the creep behavior can be described if the simple equation above is modified to take account of recovery. The observed variation of creep rate can be explained by recovery concepts only if the recovery rate depends on the strain level in addition to the strength level.
Some Factors Affecting Durability of Structural Clay Products Masonry
Authors: Johnson PV , Plummer HC
Published: September 2009

The Proceedings of the thirty-fourth annual meeting of this Society (1) include papers presented in 1931 at the Symposium on Weathering Characteristics of Masonry Materials. These materials include, stone, slate, concrete, aggregates, and clay products, and extensive bibliographies of the published literature on the weathering of these materials are presented.
Laboratory Testing and the Hurability of Concrete
Authors: Kennedy TB
Published: September 2009

Concrete structures cannot be constructed and subjected to full-scale tests for durability in a manner analogous to load tests. It therefore is necessary to estimate the durability of concrete structures by combining information gained from a study of service yielded by existing structures, controlled exposure tests of specimens, laboratory simulated-service tests, and tests and analyses of concrete and concrete materials. None of these sources of information provide a basis for adequately evaluating the effect on durability of workmanship, honesty, and intelligence that may or may not be employed in all stages of the operation from production of concrete materials to maintenance of the completed structure.

Durability of concrete structures is determined by materials, workmanship, design, and exposure. Petrographic examination of aggregates, X-ray diffraction studies of cement, freezing-and-thawing tests of concrete both in the laboratory and at field exposure stations, ultrasonic pulse velocity tests of specimens and structures, are recommended means of improving knowledge of durability of concrete and concrete structures.
Trace Analysis by Means of the Graphite Spark
Authors: Morris JM , Pink FX
Published: September 2009

A combined method for the determination of trace elements is described. Chemical separation and concentration of the impurities is followed with spectrographic analysis by means of the graphite spark.

The method based on synthetic standards has been applied successfully to the determination of parts per billion quantities in semi-conductor materials.

An outline of the chemical concent rational procedures is given. The spec-trographic techniques of the graphite spark method are described and the excitation conditions, the line pairs, and the sensitivities are listed.