bluuebunny/crossref_metadata_2025 huggingface dataset:
Etiology, Prenatal Diagnostics and Outcome of Ventriculomegaly in 230 Cases
Authors: Joó József Gábor , Tóth Zoltán , Beke Artúr , Papp Csaba , Tóth-Pál Ernő , Csaba Ákos , Szigeti Zsanett , Rab Attila , Papp Zoltán
Published: September 2008

Objective: The aim of this study was to review and summarize the information regarding the etiology, diagnostics and outcome of ventriculomegaly. Methods: The study included 230 cases of ventriculomegaly examined between 1979 and 2000. The main diagnostic criterion for ventriculomegaly was the transverse diameter of the ventricular atrium at the level of the glomus of the chorioid plexus measuring >10 mm, irrespective of gestational age. Results: Gender distribution (male:female ratio: 0.98) coincided with that of the general population. In 32% of the cases (72/230), the history was positive; 6% (12/230) had a positive genetic history, while 26% (60/230) were associated with pathological obstetric events. The incidence rate of ventriculomegaly in the patients’ history was found to be 2.61% (6/230). In nearly 60% of the cases included in this study, ventriculomegaly was diagnosed before the 24th week of pregnancy. Fresh fetal infection confirmed by Toxoplasma PCR real-time examination was diagnosed only in cases of severe ventriculomegaly. Based on the measurement of the diameter of the atrium of the lateral ventricle, severe and mild ventriculomegaly was diagnosed in 142/230 (61.7%) and 88/230 cases (38.3%), respectively. Termination of pregnancy was significantly more frequent in cases of severe than of mild ventriculomegaly (92 vs. 66%). Conclusions: The importance of positive obstetric and/or genetic history should be emphasized as it is in direct relationship with the increased incidence of this malformation. Regarding the practice of ultrasonography, mild ventriculomegaly (transverse diameter of the lateral ventricle <15 mm) has a much better prognosis than the severe form (transverse diameter of the lateral ventricle >15 mm) of the malformation. Based on the ultrasonographic diagnosis of ventriculomegaly, TORCH serological examination is also recommended since treating toxoplasmosis by medication may have a promising prognosis for the pregnancy. In cases of isolated ventriculomegaly alone, intrauterine karyotyping is not necessarily indicated, but in cases where ventriculomegaly is associated with other genetic disorders karyotyping should definitely be performed. Since ventriculomegaly is not incompatible with postnatal life by itself, the decision about the fate of the pregnancy is largely dependent on the presence of other organic disorders.
Magnetocardiography-Guided Management of an Unusual Case of Isoimmune Complete Atrioventricular Block Complicated by Ventricular Tachycardia
Authors: Das Bibhuti , Cuneo Bettina F. , Ovadia Mark , Strasburger Janette F. , Johnsrude Christopher , Wakai Ronald T.
Published: September 2008

A fetus who was diagnosed at 25 weeks of gestation with isoimmune AV block presented at 34 weeks with a precipitous fall in ventricular rate and periods of tachycardia. Magnetocardiography revealed the tachycardia to be ventricular. After delivery, nonsustained ventricular tachycardia continued. The baby then successfully paced, and at higher ventricular rates the tachycardia resolved. Five years later the child has normal ventricular function and is doing well.
Monopitched Expression of Emotions in Different Vowels
Authors: Waaramaa Teija , Laukkanen Anne-Maria , Alku Paavo , Väyrynen Eero
Published: September 2008

Fundamental frequency (F₀) and intensity are known to be important variables in the communication of emotions in speech. In singing, however, pitch is predetermined and yet the voice should convey emotions. Hence, other vocal parameters are needed to express emotions. This study investigated the role of voice source characteristics and formant frequencies in the communication of emotions in monopitched vowel samples [a:], [i:] and [u:]. Student actors (5 males, 8 females) produced the emotional samples simulating joy, tenderness, sadness, anger and a neutral emotional state. Equivalent sound level (Leq), alpha ratio [SPL (1–5 kHz) – SPL (50 Hz–1 kHz)] and formant frequencies F1–F4 were measured. The [a:] samples were inverse filtered and the estimated glottal flows were parameterized with the normalized amplitude quotient [NAQ = fAC/(dpeakT)]. Interrelations of acoustic variables were studied by ANCOVA, considering the valence and psychophysiological activity of the expressions. Forty participants listened to the randomized samples (n = 210) for identification of the emotions. The capacity of monopitched vowels for conveying emotions differed. Leq and NAQ differentiated activity levels. NAQ also varied independently of Leq. In [a:], filter (formant frequencies F1–F4) was related to valence. The interplay between voice source and F1–F4 warrants a synthesis study.
Propofol Sedation for Endoscopic Procedures in Patients 90 Years of Age and Older
Authors: Horiuchi Akira , Nakayama Yoshiko , Tanaka Naoki , Ichise Yasuyuki , Katsuyama Yoshihiko , Ohmori Shigeru
Published: September 2008

Background and Aim: There are only a few studies on propofol sedation for very elderly patients. The present study was undertaken to evaluate the safety of propofol sedation in patients 90 years of age and older undergoing endoscopic procedures. Methods: We prospectively assessed endoscopic procedures for patients 90 years of age and older using propofol sedation. Endoscopic procedures, dosage used, respiratory depression, complications and 30-day mortality were evaluated. In a subset of the enrolled patients, the blood concentrations of propofol were measured. Results: All 241 patients completed endoscopic procedures. For esophagogastroduodenoscopy, percutaneous endoscopic gastrostomy, colonoscopy, and endoscopic retrograde cholangiopancreatography, the mean propofol doses used were 22, 24, 46 and 42 mg, respectively. Four patients required oxygen and 1 patient was treated by short periods of mask ventilation. There was no perforation, bleeding, pancreatitis or 30-day mortality. In diagnostic esophagogastroduodenoscopy, the level of sedation and propofol blood concentrations after administration of propofol (24 ± 6.8 mg) in patients 90 years of age and older corresponded to those of propofol (61 ± 13 mg) in middle-aged patients (control). Conclusion: Low-dose propofol sedation is safe and may be enough for patients 90 years of age and older undergoing endoscopic procedures.
Transforming Growth Factor-β Signaling in Thoracic Aortic Aneurysm Development: A Paradox in Pathogenesis
Authors: Jones Jeffrey A. , Spinale Francis G. , Ikonomidis John S.
Published: September 2008

Thoracic aortic aneurysms (TAAs) are potentially devastating, and due to their asymptomatic behavior, pose a serious health risk characterized by the lack of medical treatment options and high rates of surgical morbidity and mortality. Independent of the inciting stimuli (biochemical/mechanical), TAA development proceeds by a multifactorial process influenced by both cellular and extracellular mechanisms, resulting in alterations of the structure and composition of the vascular extracellular matrix (ECM). While the role of enhanced ECM proteolysis in TAA formation remains undisputed, little attention has been focused on the upstream signaling events that drive the remodeling process. Recent evidence highlighting the dysregulation of transforming growth factor-β (TGF-β) signaling in ascending TAAs from Marfan syndrome patients has stimulated an interest in this intracellular signaling pathway. However, paradoxical discoveries have implicated both enhanced TGF-β signaling and loss of function TGF-β receptor mutations, in aneurysm formation; obfuscating a clear functional role for TGF-β in aneurysm development. In an effort to elucidate this subject, TGF-β signaling and its role in vascular remodeling and pathology will be reviewed, with the aim of identifying potential mechanisms of how TGF-β signaling may contribute to the formation and progression of TAA.
Lateralization of 17Beta-Hydroxysteroid Dehydrogenase Type 10 in Hippocampi of Demented and Psychotic People
Authors: Hovorkova Petra , Kristofikova Zdena , Horinek Ales , Ripova Daniela , Majer Emerich , Zach Petr , Sellinger Pavel , Ricny Jan
Published: September 2008

Objective: The multifunctional mitochondrial enzyme 17β-hydroxysteroid dehydrogenase type 10 could play a role in the development of Alzheimer disease via its high-affinity binding to amyloid-β peptides and its overexpression. Methods: We evaluated the specificity of alterations in mRNA/enzyme expression levels in human right and left hippocampi. Results: We observed a trend towards right/left laterality in nondemented nonpsychotic controls; however, the degree of asymmetry was higher for mRNA when compared to enzyme expression levels. In Alzheimer disease and schizophrenia, significant shifts to left/right asymmetry were found and the changes were associated with more marked increases in mRNA/enzyme expression in the left hemisphere. On the other hand, no alterations were observed in people with multi-infarct dementia. Conclusion: Our results support studies reporting an impairment of mitochondria in Alzheimer disease or schizophrenia and a higher vulnerability of the dominant hemisphere to pathological processes. Overexpression of the enzyme could be used to distinguish Alzheimer disease from multi-infarct dementia.
The Extended Tau Haplotype and the Age of Onset of Dementia in Down Syndrome
Authors: Jones Emma L. , Margallo-Lana Marisa , Prasher Vee P. , Ballard Clive G.
Published: September 2008

Background/Aims: Most people with Down syndrome (DS) develop Alzheimer’s disease (AD). The extended tau haplotype has been linked to AD. In this study, we examined the haplotype’s effect on the age of onset of AD in DS. Methods: People with DS were assessed for dementia. Genotyping was performed for the extended tau haplotype, APOE anda polymorphism in APP, attt5–8. Results: Haplotype frequencies vary between those developing AD before 45 and those developing dementia after this age (p = 0.03). H1/H2 individuals are more likely to develop dementia before 45 than H1/H1 individuals (OR = 3, 95% CI = 1.01–8.91). Conclusion: Even in a condition driven by excess amyloid pathology, factors affecting tau are also important and should be considered as potential treatment targets.
Neuropilin-1 Is Essential for Enhanced VEGF165-Mediated Vasodilatation in Collateral-Dependent Coronary Arterioles of Exercise-Trained Pigs
Authors: Fogarty Jennifer A. , Delp Michael D. , Muller-Delp Judy M. , Laine Glen A. , Parker Janet L. , Heaps Cristine L.
Published: September 2008

Background/Aims: Exercise training enhances vasodilatation to vascular endothelial growth factor (VEGF165) in collateral-dependent coronary arterioles. Interaction of VEGF receptor 2 (VEGFR-2) and the non-tyrosine-kinase receptor, neuropilin-1 has been reported to potentiate VEGF165-mediated signaling. In the current study, we tested the hypotheses that neuropilin-1 mediates the exercise-enhanced VEGF165-mediated vasodilatation in collateral-dependent arterioles and that neuropilin-1 and/or VEGFR-2 protein levels are increased in these arterioles. Methods: Ameroid occluders were surgically placed around the proximal left circumflex coronary artery of miniature swine. Eight weeks after surgery, the animals were randomized into sedentary or exercise training (treadmill run; 5 days/week; 14 weeks) protocols. Coronary arterioles (∼100 μm diameter) were isolated from both collateral-dependent and control (left anterior descending) myocardial regions and studied by in vitro videomicroscopy or frozen for immunoblot analysis. Results: Exercise-enhanced VEGF165-mediated vasodilatation in collateral-dependent arterioles was reversed by inhibition of the VEGF165-neuropilin-1 interaction. VEGF121, which does not interact with neuropilin-1, induced similar vasodilatation in arterioles from all treatment groups. Immunoblot revealed significantly elevated VEGFR-1, VEGFR-2 and neuropilin-1 protein levels in collateral-dependent arterioles of exercise-trained pigs. Conclusions: Neuropilin-1 plays a vital role in the exercise-enhanced VEGF165-mediated vasodilatation of collateral-dependent coronary arterioles and is associated with increased neuropilin-1 receptor protein levels.
Efficacy of Partially Hydrolyzed Guar Gum-Added Oral Rehydration Solution in the Treatment of Severe Cholera in Adults
Authors: Alam N.H. , Ashraf H. , Sarker S.A. , Olesen M. , Troup J. , Salam M.A. , Gyr N. , Meier R.
Published: September 2008

Background: Partially hydrolyzed guar gum (PHGG) is a water-soluble fiber if added to oral rehydration solution (ORS) and undergoes fermentation in the colon liberating short chain fatty acids (SCFAs). SCFAs potentiate the effect of ORS, reducing the severity of diarrhea. Aim: To examine the effect of PHGG-added ORS in reducing the stool output and duration of diarrhea in adult cholera. Methods: 195 male patients were studied in a randomized controlled trial: (a) 65 received ORS + 25 g PHGG; (b) 65 received ORS + 50 g PHGG, and (c) 65 received ORS alone (control). Major outcomes were stool weight and duration of diarrhea. Results: No significant differences were found in mean ± SD stool weight (g/kg b.w.) during the first and second 24 h. In the subgroup analysis (excluding very high purging patients, stool weight in the first 24 h was >10 kg), the stool weight (g/kg b.w.) was significantly reduced in the first 24 h in both groups receiving PHGG (PHGG 25 g, 136 ± 68 vs. PHGG 50 g, 144 ± 49 vs. control, 176 ± 43, p = 0.01). Conclusion: PHGG-added ORS might have a beneficial effect in moderately purging adult cholera. However, further studies are warranted to confirm the preliminary findings.
Decreased Use of Postnatal Corticosteroids in Extremely Preterm Infants without Increasing Chronic Lung Disease
Authors: Seth Rakesh , Gray Peter H. , Tudehope David I.
Published: September 2008

Background: Postnatal corticosteroidsare effective in preventing chronic lung disease in preterm infant. There are concerns that corticosteroid use may be associated with an increased risk of impaired neurodevelopment. Objective: To examine the effect of change in practice with the use of postnatal corticosteroids over an 8-year period in extremely preterm babies on the incidence of chronic lung disease (CLD) and cerebral palsy at 1 year of age. Methods: Babies of birth weight <1,000 g or gestational age <28 weeks admitted from 1997 to 2004 were included in this retrospective analysis. The study period was divided into two eras: group 1: 1997–2000, group 2: 2001–2004. Data were collected from the neonatal database, individual records and from the Growth and Development Unit. The outcome measure of CLD was defined as oxygen dependency at 36 weeks postmenstrual age. Data for postnatal corticosteroid usage were collected for the number of babies per year, and total dose. Results: 389 group 1 babies were compared to 368 group 2 babies. There was a significant decrease in the use of dexamethasone from 27% in group 1 to 13% in group 2 (p = 0.0001), and total dose – mg/kg (4.5 ± 2.9 vs. 2.6 ± 1.6, p = 0.0001). The incidence of CLD and need for home oxygen was similar between groups. The incidence of cerebral palsy reduced from 10.4% in group 1 to 6.6% in group 2, though this was not statistically significant (OR 0.63; 95% CI 0.3, 1.2.). Conclusion: Decreased postnatal corticosteroid use had no impact on the incidence of CLD or need for home oxygen therapy. The trend towards a reduced rate of cerebral palsy requires further investigation.
Stimulation of Erythrocyte Cell Membrane Scrambling by Methyldopa
Authors: Mahmud Hasan , Föller Michael , Lang Florian
Published: September 2008

Methyldopa is used for treatment of hypertension in pregnancy. Side effects of methyldopa include anemia, which could result from decreased formation or accelerated death of circulating erythrocytes. Several drugs cause anemia by triggering of suicidal erythrocyte death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling, the latter leading to phosphatidylserine exposure at the erythrocyte surface. Stimulators of erythrocyte membrane scrambling include increased cytosolic Ca2+ concentration ([Ca2+]i) and ceramide. Phosphatidylserine-exposing cells are rapidly cleared from circulating blood. The present study explored whether eryptosis could be triggered by methyldopa. Erythrocytes from healthy volunteers were exposed to methyldopa, and phosphatidylserine exposure (annexin A5 binding), cell volume (forward scatter), [Ca2+]i (Fluo3-dependent fluorescence), and ceramide formation (anti-ceramide-fluorescein isothiocyanate antibody) were determined by flow cytometry. Methyldopa (6 μg/ml) did not increase [Ca2+]i but led to stimulation of ceramide formation resulting in significant phosphatidylserine exposure and, at higher concentrations, to cell shrinkage. Methyldopa further decreased the GSH/GSSG ratio, pointing to oxidative stress. The scavenger N-acetyl-L-cysteine significantly blunted methyldopa-induced eryptosis. Clearance of erythrocytes from circulating blood was significantly accelerated by treatment with methyldopa. The present observations disclose a novel action of methyldopa, which may well contribute to drug-induced anemia.
Opportunity for Selection during the 17th–19th Centuries in the Diocese of Linköping as Estimated with Crow’s Index in a Population of Clergymen’s Wives
Authors: Hed Helen
Published: September 2008

Opportunity for selection in human populations can be estimated by means of Crow’s index, which is the sum of two indices, one measuring prefertile mortality and the other reproductive performance. Data on the population under study (1,616 clergymen’s wives in the diocese of LinkÖping born 1600–1850) were obtained from a biography of all the clergymen in the diocese during the period of study. The total material was divided into 9 time periods. Crow’s index was found to vary over time. This variation was influenced by fluctuations in both index components. A comparison of the indices for the period 1800–1849 with those from two other contemporary Swedish populations, Fleninge (county of MalmÖhus) and NedertorneÅ (county of Norrbotten), was performed. The highest index was found for NedertorneÅ, the lowest for Fleninge, while the index for the LinkÖping population is intermediate. The bias introduced by different strategies for data collection is discussed.
a1-Antitrypsin Types in Schizophrenia
Authors: Rudduck C. , Franzén G. , LindstrÖm L.
Published: September 2008

The gene and phenotype frequencies of Α1-antitrypsin were studied in patients with (49) and without (92) a family history of schizophrenia. A significant difference with respect to phenotype (p& <0.05) and gene (&p< 0.025) frequencies was found between the two groups of patients. Among patients with a family history of schizophrenia there was a significant increase of the M1 gene and a decrease of the M2 gene. There were no significant differences between schizophrenic patients and controls.
Implementation of Guidelines for the Treatment of Acute ST-Elevation Myocardial Infarction
Authors: Flesch Markus , Hagemeister Jens , Berger Hans-Joerg , Schiefer Annett , Schynkowski Sylke , Klein Martin , Sahebdjami Sassan , vom Dahl Stephan , Fehske Wolfgang , Mies Rudolf , von Eiff Michael , Pfaff Holger , Frommolt Peter , Hoepp Hans-Wilhelm
Published: September 2008

Background—

The aim of the Köln (Cologne) Infarction Model is to examine the feasibility of obligatory treatment of ST-segment–elevation myocardial infarction (STEMI) by first-line percutaneous coronary intervention.

Methods and Results—

The study was performed in Cologne with >1 million citizens, 5 coronary intervention centers, and 11 primary care hospitals. Twelve-lead ECG was available for all emergency medical service (EMS) teams. Partners guaranteed direct transfer of STEMI patients to a catheterization laboratory. A total of 519 patients treated within KIM in 2006 were included in the study. Of these, 24% presented at a primary care hospital, 11% presented directly at a coronary intervention center, 5% were transferred by EMS to primary care hospitals, and 60% were directly transferred by EMS to a catheterization laboratory. In 91% of cases, the catheterization laboratory was notified of the patient’s arrival in advance. False-positive ECG diagnosis of STEMI by EMS accounted for 6%. Median treatment times were as follows: from the start of symptoms to first medical contact, 120 minutes; phone to balloon, 70 minutes; and door to balloon, 49 minutes. Of all patients, 93% underwent angiography; 409 patients were treated by coronary intervention, and 24 underwent emergency coronary artery bypass graft. Thrombolysis in Myocardial Infarction grade 3 flow was obtained in 89%. In the hospitals, deaths and new myocardial infarctions were observed in 12.1% and in 1.9% of all patients, respectively.

Conclusion—

The Cologne Infarction Model provides evidence for the feasibility of obligatory treatment of STEMI by primary coronary intervention in a metropolitan setting. Acceptance of treatment pathways allowed nearly all STEMI patients to undergo coronary angiography. ECG competence of EMS was excellent. Treatment times were within postulated limits. Results, including mortality, were within a high quality range.
Procedural Safety and Potential Vascular Complication of Endovascular Recanalization for Chronic Cervical Internal Carotid Artery Occlusion
Authors: Lin Mao-Shin , Lin Lung-Chun , Li Hung-Yuan , Lin Cheng-Hsin , Chao Chi-Chao , Hsu Chih-Neng , Lin Yen-Hung , Chen Shih-Chung , Wu Yen-Wen , Kao Hsien-Li
Published: September 2008

Background—

Patients with chronic cervical internal carotid artery occlusion (ICAO) and cerebral ischemia may benefit from revascularization. The feasibility of endovascular recanalization for chronic ICAO has been reported recently, but its safety is still unproven. We report the follow-up results of 54 chronic ICAO patients who underwent endovascular recanalization, focusing on potential vascular complications and corresponding management.

Methods and Results—

Endovascular recanalization for chronic ICAO was attempted in 54 consecutive patients (48 men; 69.2�9.8 years old) with either recurrent neurological deficit or objective ipsilateral hemisphere ischemia. Mean duration from occlusion documentation to the procedure was 237�327 days (range, 56 to 1424 days). Adverse events while in the hospital and during the 3-month follow-up were recorded. Successful recanalization was achieved in 35 of 54 patients (65%). Three-month cumulative stroke and death rate was 4% (2 of 54), including 1 in-hospital fatal nonipsilateral stroke and 1 in-hospital minor ipsilateral stroke secondary to systemic hypotension. Vascular complications developed in 3 of 54 patients (6%), including 1 late pseudoaneurysm formation 3 months after recanalization, 1 immediate carotid-cavernous fistula after recanalization, and 1 minor extravasation at carotid bifurcation after failed recanalization. However, no clinical sequela was noted with close follow-up and adequate management.

Conclusion—

Certain immediate or delayed vascular complications may develop during or after the endovascular recanalization for chronic ICAO. Although periprocedural death and stroke rate is limited in our study, further study combining neuroimaging tools and cognitive function evaluation is mandatory to assess its utility and appropriateness in patients with chronic ICAO.
Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction
Authors: Kukreja Neville , Onuma Yoshinobu , Garcia-Garcia Hector , Daemen Joost , van Domburg Ron , Serruys Patrick W.
Published: September 2008

Background—

Primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction with bare metal stents (BMS) is well established, while randomized trials suggest equivalent safety and reduced repeat revascularization with drug-eluting stents (DES) in this setting. However, long-term data on DES in PPCI is lacking, especially in those ineligible for inclusion in randomized trials. Our aim was to investigate the long-term outcomes of unselected patients undergoing PPCI with BMS and DES.

Methods and Results—

We analyzed all patients (n=1738) undergoing PPCI for a de novo lesion in our institution from 2000 to 2005. Patients from 3 sequential consecutive cohorts of BMS (n=531), sirolimus-eluting (SES, n=185) or paclitaxel-eluting stents (PES, n=1022) were included. The median duration of follow-up was 1185 days (interquartile range, 746 to 1675). There were no differences in all-cause mortality or repeat revascularization between DES and BMS, although there was a nonsignificant trend toward improved survival with SES compared with both BMS (propensity score-adjusted hazard ratio, 0.63; [95%CI, 0.33 to 1.18]) and PES (hazard ratio, 0.71; [95% CI, 0.40 to 1.26]). SES were associated with lower rates of the composite end point of all-cause death, nonfatal myocardial infarction, or target vessel revascularization (hazard ratio, 0.62; 95%CI, 0.40 to 0.96) when compared with PES. Very late stent thrombosis only occurred in the DES groups.

Conclusions—

Although DES are not associated with an increase in adverse events compared with BMS when used for PPCI, neither DES reduced repeat revascularizations. Appropriately powered randomized trials with hard clinical end points and an “all-comer” design are required to further assess the benefit of DES in PPCI.
Retrograde Transarterial Implantation of a Nonmetallic Aortic Valve Prosthesis in High–Surgical-Risk Patients With Severe Aortic Stenosis
Authors: Schofer Joachim , Schlüter Michael , Treede Hendrik , Franzen Olaf W. , Tübler Thilo , Pascotto Andrea , Low Reginald I. , Bolling Steven F. , Meinertz Thomas , Reichenspurner Hermann
Published: September 2008

Background—

To assess the feasibility and safety of retrograde transarterial implantation of a novel nonmetallic aortic valve prosthesis (Direct Flow Medical Inc, Santa Rosa, Calif), a prospective single-center study was performed in patients with severe aortic stenosis at high risk for open-heart surgery.

Methods and Results—

Fifteen patients (intention-to-treat cohort) with an aortic valve area ≤0.8 cm
2
, a ≥35-mm Hg mean transvalvular pressure gradient, and a logistic EuroSCORE ≥20% were enrolled. Percutaneous aortic valve replacement was performed with the patient under general anesthesia. Hemodynamic parameters were assessed before and after implantation by transesophageal echocardiography. Clinical follow-up and transthoracic echocardiographic assessment were obtained at 30 days. Procedural success was achieved in 12 patients (80%). Surgical conversion became necessary at day 2 in 1 patient; 11 patients (73%) were discharged with a permanent implant. In these patients, implantation resulted acutely in a significant increase in aortic valve area (median, 1.64 [interquartile range, 1.27 to 1.74] versus 0.60 [0.46 to 0.69] cm
2
;
P
=0.0033) and a concomitant reduction in the mean pressure gradient (14.0 [13.2 to 16.5] versus 54.0 [43.2 to 59.8] mm Hg;
P
=0.0033). At 30 days, 1 cardiac death (6.7%; 95% CI, 0.2% to 32.0%) and 1 major stroke were observed. The 10 surviving patients with a permanent implant showed marked hemodynamic and clinical improvement at this time point.

Conclusions—

In this small series of patients, percutaneous implantation of the Direct Flow Medical aortic valve prosthesis in high–surgical-risk patients was feasible and associated with a reasonably low safety profile.
Mesoscale Atmospheric Modeling Using a High Horizontal Grid Resolution over a Complex Coastal Terrain and a Wine Region of South Africa
Authors: Bonnardot V. , Cautenet S.
Published: September 2008

The Regional Atmospheric Modeling System (RAMS) was used to assess local air circulation patterns over the wine-producing Stellenbosch region of South Africa. Numerical simulations using four nested grids (25, 5, and 1 km, and 200 m of horizontal resolution) were performed for each day of February 2000 (during the grape-ripening period) over southern Western Cape Province. Modeled hourly data were extracted from the analysis files and used to produce mean hourly fields (temperature, relative humidity, wind speed, and radiation). Three runs with increasing horizontal resolutions for the finer grid were performed (run 1 with two nested grids of 25 and 5 km; run 2 with three nested grids of 25, 5, and 1 km; run 3 with four nested grids of 25, 5, and 1 km, and 200 m). For each event, the simulations of 1-km and 200-m resolution were superior to the 5-km-resolution simulation, especially in reproducing the local air circulations (sea and slopes breezes) because of a better representation of the local terrain (topography and vegetation cover). The use of a high-resolution grid (200 m) may be of greater value in the identification of potential terrain for viticulture.
Extreme Rainfall Events in the Hawaiian Islands
Authors: Chu Pao-Shin , Zhao Xin , Ruan Ying , Grubbs Melodie
Published: September 2008

Heavy rainfall and the associated floods occur frequently in the Hawaiian Islands and have caused huge economic losses as well as social problems. Extreme rainfall events in this study are defined by three different methods based on 1) the mean annual number of days on which 24-h accumulation exceeds a given daily rainfall amount, 2) the value associated with a specific daily rainfall percentile, and 3) the annual maximum daily rainfall values associated with a specific return period. For estimating the statistics of return periods, the three-parameter generalized extreme value distribution is fit using the method of L-moments. Spatial patterns of heavy and very heavy rainfall events across the islands are mapped separately based on the aforementioned three methods. Among all islands, the pattern on the island of Hawaii is most distinguishable, with a high frequency of events along the eastern slopes of Mauna Kea and a low frequency of events on the western portion so that a sharp gradient in extreme events from east to west is prominent. On other islands, extreme rainfall events tend to occur locally, mainly on the windward slopes. A case is presented for estimating return periods given different rainfall intensity for a station in Upper Manoa, Oahu. For the Halloween flood in 2004, the estimated return period is approximately 27 yr, and its true value should be no less than 13 yr with 95% confidence as determined from the adjusted bootstrap resampling technique.
A Hurricane Boundary Layer and Wind Field Model for Use in Engineering Applications
Authors: Vickery Peter J. , Wadhera Dhiraj , Powell Mark D. , Chen Yingzhao
Published: September 2008

This article examines the radial dependence of the height of the maximum wind speed in a hurricane, which is found to lower with increasing inertial stability (which in turn depends on increasing wind speed and decreasing radius) near the eyewall. The leveling off, or limiting value, of the marine drag coefficient in high winds is also examined. The drag coefficient, given similar wind speeds, is smaller for smaller-radii storms; enhanced sea spray by short or breaking waves is speculated as a cause. A fitting technique of dropsonde wind profiles is used to model the shape of the vertical profile of mean horizontal wind speeds in the hurricane boundary layer, using only the magnitude and radius of the “gradient” wind. The method slightly underestimates the surface winds in small but intense storms, but errors are less than 5% near the surface. The fit is then applied to a slab layer hurricane wind field model, and combined with a boundary layer transition model to estimate surface winds over both marine and land surfaces.
Linking the Pacific Meridional Mode to ENSO: Utilization of a Noise Filter
Authors: Zhang Li , Chang Ping , Tippett Michael K.
Published: September 2008

A novel noise filter is used to effectively reduce internal atmospheric variability in the air–sea fluxes of a coupled model. This procedure allows for a test of the impact of the internal atmospheric variability on ENSO through its effect on the Pacific meridional mode (MM). Three 100-yr coupled experiments are conducted, where the filter is utilized to suppress internal atmospheric variability in 1) both the surface wind stress and the heat flux (fully filtered run), 2) only the surface heat flux (filtered-flux run), and 3) only the surface wind stress (filtered-wind run). The fully filtered run indicates that suppressing internal atmospheric variability weakens the MM, which in turn results in substantially reduced ENSO variability. ENSO is no longer phase locked to the boreal winter. The filtered-flux and filtered-wind experiments reveal that different types of noise affect ENSO in different ways. The noise in the wind stress does not have a significant impact on the MM and its relationship to ENSO. This type of noise, however, tends to broaden the spectral peak of ENSO while shifting it toward lower frequencies. The noise in the heat flux, on the other hand, has a direct impact on the strength of the MM and consequently its ability to influence ENSO. Reducing the effect of heat flux noise yields substantially weakened MM activity and a weakened relationship to ENSO, which leads to altered seasonal phase-locking characteristics.
The Dynamical Response to Snow Cover Perturbations in a Large Ensemble of Atmospheric GCM Integrations
Authors: Fletcher Christopher G. , Hardiman Steven C. , Kushner Paul J. , Cohen Judah
Published: September 2008

Variability in the extent of fall season snow cover over the Eurasian sector has been linked in observations to a teleconnection with the winter northern annular mode pattern. Here, the dynamics of this teleconnection are investigated using a 100-member ensemble of transient integrations of the GFDL atmospheric general circulation model (AM2). The model is perturbed with a simple persisted snow anomaly over Siberia and is integrated from October through December. Strong surface cooling occurs above the anomalous Siberian snow cover, which produces a tropospheric form stress anomaly associated with the vertical propagation of wave activity. This wave activity response drives wave–mean flow interaction in the lower stratosphere and subsequent downward propagation of a negative-phase northern annular mode response back into the troposphere. A wintertime coupled stratosphere–troposphere response to fall season snow forcing is also found to occur even when the snow forcing itself does not persist into winter. Finally, the response to snow forcing is compared in versions of the same model with and without a well-resolved stratosphere. The version with the well-resolved stratosphere exhibits a faster and weaker response to snow forcing, and this difference is tied to the unrealistic representation of the unforced lower-stratospheric circulation in that model.
Time-Varying Across-Shelf Ekman Transport and Vertical Eddy Viscosity on the Inner Shelf
Authors: Kirincich Anthony R. , Barth John A.
Published: September 2008

The event-scale variability of across-shelf transport was investigated using observations made in 15 m of water on the central Oregon inner shelf. In a study area with intermittently upwelling-favorable winds and significant density stratification, hydrographic and velocity observations show rapid across-shelf movement of water masses over event time scales of 2–7 days. To understand the time variability of across-shelf exchange, an inverse calculation was used to estimate eddy viscosity and the vertical turbulent diffusion of momentum from velocity profiles and wind forcing. Depth-averaged eddy viscosity varied over a large dynamic range, but averaged 1.3 × 10−3 m2 s−1 during upwelling winds and 2.1 × 10−3 m2 s−1 during downwelling winds. The fraction of full Ekman transport present in the surface layer, a measure of the efficiency of across-shelf exchange at this water depth, was a strong function of eddy viscosity and wind forcing, but not stratification. Transport fractions ranged from 60%, during times of weak or variable wind forcing and low eddy viscosity, to 10%–20%, during times of strong downwelling and high eddy viscosity. The difference in eddy viscosities between upwelling and downwelling led to varying across-shelf exchange efficiencies and, potentially, increased net upwelling over time. These results quantify the variability of across-shelf transport efficiency and have significant implications for ecological processes (e.g., larval transport) in the inner shelf.
The Formation of Parasitic Capillary Ripples on Gravity–Capillary Waves and the Underlying Vortical Structures
Authors: Hung Li-Ping , Tsai Wu-Ting
Published: September 2008

The evolution of moderately short, steep two-dimensional gravity–capillary waves, from the onset of the parasitic capillary ripples to a fully developed quasi-steady stage, is studied numerically using a spectrally accurate model. The study focuses on understanding the precise mechanism of capillary generation, and on characterizing surface roughness and the underlying vortical structure associated with parasitic capillary waves. It is found that initiation of the first capillary ripple is triggered by the fore–aft asymmetry of the otherwise symmetric carrier wave, which then forms a localized pressure disturbance on the forward face near the crest, and subsequently develops an oscillatory train of capillary waves. Systematic numerical experiments reveal that there exists a minimum crest curvature of the carrier gravity–capillary wave for the formation of parasitic capillary ripples, and such a threshold curvature (≈0.25 cm−1) is almost independent of the carrier wavelength. The characteristics of the parasitic capillary wave train and the induced underlying vortical structures exhibit a strong dependence on the carrier wavelength. For a steep gravity–capillary wave with a shorter wavelength (e.g., 5 cm), the parasitic capillary wave train is distributed over the entire carrier wave surface at the stage when capillary ripples are fully developed. Immediately underneath the capillary wave train, weak vortices are observed to confine within a thin layer beneath the ripple crests whereas strong vortical layers with opposite orientation of vorticity are shed from the ripple troughs. These strong vortical layers are then convected upstream and accumulate within the carrier wave crest, forming a strong “capillary roller” as postulated by Longuet-Higgins. In contrast, as the wavelength of the gravity–capillary wave increases (e.g., 10 cm), parasitic capillary ripples appear as being trapped in the forward slope of the carrier wave. The strength of the vortical layer shed underneath the parasitic capillaries weakens, and its thickness and extent reduces. The vortices accumulating within the crest of the carrier wave, therefore, are not as pronounced as those observed in the shorter gravity–capillary waves.
Influence of Ground Clutter Contamination on Polarimetric Radar Parameters
Authors: Friedrich Katja , Germann Urs , Tabary Pierre
Published: September 2008

The influence of ground clutter contamination on the estimation of polarimetric radar parameters, horizontal reflectivity (Zh), differential reflectivity (Zdr), correlation coefficient (ρhυ), and differential propagation phase (ϕdp) was examined. This study aims to derive the critical level of ground clutter contamination for Zh, Zdr, ρhυ, and ϕdp at which ground clutter influence exceeds predefined precision thresholds. Reference data with minimal ground clutter contamination consist of eight precipitation fields measured during three rain events characterized by stratiform and convective precipitation. Data were collected at an elevation angle of 0.8° by the Météo-France operational, polarimetric Doppler C-band weather radar located in Trappes, France, ∼30 km southwest of Paris. Nine different ground clutter signatures, ranging from point targets to more complex signatures typical for mountain ranges or urban obstacles, were added to the precipitation fields. This is done at the level of raw in-phase and quadrature component data in the two polarimetric channels. For each ground clutter signature, 30 simulations were conducted in which the mean reflectivity of ground clutter within the resolution volume varied between being 30 dB higher to 30 dB lower than the mean reflectivity of precipitation. Differences in Zh, Zdr, ρυ, and ϕdp between simulation and reference were shown as a function of ratio between ground clutter and precipitation intensities.

As a result of this study, horizontal reflectivity showed the lowest sensitivity to ground clutter contamination. Furthermore, a precision of 1.7 dBZ in Zh is achieved on average when the precipitation and ground clutter intensities are equal. Requiring a precision of 0.2 dB in Zdr and 3° in ϕdp, the reflectivity of precipitation needs to be on average ∼5.5 and ∼6 dB, respectively, higher compared to the reflectivity of ground clutter. The analysis also indicates that the highest sensitivity to the nine clutter signatures was derived for ρhυ. To meet a predefined precision threshold of 0.02, reflectivity of precipitation needs to be ∼13.5 dB higher than the reflectivity of ground clutter.
Availability of High-Quality TRMM Ground Validation Data from Kwajalein, RMI: A Practical Application of the Relative Calibration Adjustment Technique
Authors: Marks David A. , Wolff David B. , Silberstein David S. , Tokay Ali , Pippitt Jason L. , Wang Jianxin
Published: September 2008

Since the Tropical Rainfall Measuring Mission (TRMM) satellite launch in November 1997, the TRMM Satellite Validation Office (TSVO) at NASA Goddard Space Flight Center (GSFC) has been performing quality control and estimating rainfall from the KPOL S-band radar at Kwajalein, Republic of the Marshall Islands. Over this period, KPOL has incurred many episodes of calibration and antenna pointing angle uncertainty. To address these issues, the TSVO has applied the relative calibration adjustment (RCA) technique to eight years of KPOL radar data to produce Ground Validation (GV) version 7 products. This application has significantly improved stability in KPOL reflectivity distributions needed for probability matching method (PMM) rain-rate estimation and for comparisons to the TRMM precipitation radar (PR). In years with significant calibration and angle corrections, the statistical improvement in PMM distributions is dramatic. The intent of this paper is to show improved stability in corrected KPOL reflectivity distributions by using the PR as a stable reference. Intermonth fluctuations in mean reflectivity differences between the PR and corrected KPOL are on the order of ±1–2 dB, and interyear mean reflectivity differences fluctuate by approximately ±1 dB. This represents a marked improvement in stability with confidence comparable to the established calibration and uncertainty boundaries of the PR. The practical application of the RCA method has salvaged eight years of radar data that would have otherwise been unusable and has made possible a high-quality database of tropical ocean–based reflectivity measurements and precipitation estimates for the research community.
Retrieval of High-Resolution Wind Fields over the Southern Korean Peninsula Using the Doppler Weather Radar Network
Authors: Park S-G. , Lee Dong-Kyou
Published: September 2008

The performance of a radar network for retrieving high-resolution wind fields over South Korea is examined. The network consists of a total of 18 operational radars. All of the radars possess the Doppler capability and carry out plan position indicator (PPI) volume scans comprising 6–15 elevation steps at every 6 or 10 min. An examination of the coverage of the radar network reveals that the radar network allows the retrieval of three-dimensional high-resolution wind fields over the entire area of the southern Korean Peninsula as well as nearby oceans above a height of approximately 3 km. After the quality control procedures of the radar measurements, the high-resolution wind fields (a few kilometers) are extracted using multiple-Doppler wind synthesis in the Custom Editing and Display of Reduced Information in Cartesian Space (CEDRIC) package developed by NCAR. The radar-retrieved winds are evaluated using the following two rain events: 1) Typhoon Ewiniar in 2006, which resulted in strong winds and heavy rainfall over the entire southern Korean Peninsula, and 2) a well-developed hook echo with a relatively small-scale diameter of about 30 km. The wind fields retrieved from the radar network exhibit counterclockwise rotation around the typhoon center and a general structure around a hook echo such as a cyclonically rotating updraft (i.e., mesocyclone). Comparisons with the wind measurements from four UHF wind profilers for the typhoon case reveal that the u- and υ-wind components retrieved from the radar network deviate by standard deviations of 3.6 and 4.5 m s−1 over ranges from −30 to 20 m s−1 and from 0 to 40 m s−1, respectively. Therefore, it is concluded that the operational radar network has the potential to provide three-dimensional high-resolution wind fields within the mesoscale precipitation systems over almost the entire area of the southern Korean Peninsula.
What Are the Consequences If the Assumption of Independent Observations Is Violated in Reliability Generalization Meta-Analysis Studies?
Authors: Romano Jeanine L. , Kromrey Jeffrey D.
Published: September 2008

This study was conducted to evaluate alternative analysis strategies for the meta-analysis method of reliability generalization when the reliability estimates are not statistically independent. Five approaches to dealing with the violation of independence were implemented: ignoring the violation and treating each observation as independent, calculating one mean or median from each study, selecting only one observation per study, and using a mixed-effects model. Monte Carlo methods were used to simulate samples under known and controlled population conditions. The results suggest that the type of approach does not have a noticeable impact on the accuracy of the reliability results but that researchers should be cautious when the intraclass correlation is relatively large. The simulations in this study also resulted in very poor confidence band coverage.
Preface
Authors: Flanagan Timothy J.
Published: September 2008

If we select certain prisoners to bear the burden of heavier sentences... surely we have a moral obligation at least to allow those serving extended terms an opportunity to make some constructive use of the time we have demanded of them. And unless we intend to lock them away forever, our reasons for attempting to rehabilitate these prisoners are not only moral but eminently practical. (Norval Morris, The Future of Imprisonment. Chicago: University of Chicago Press, 1974).
Peak and Off-Peak Use: Redistributing the Outdoor Recreation/Tourism Load
Authors: Manning Robert E. , Powers Lawrence A.
Published: September 2008

Uneven distribution of use over time (peaking) is one of the most pervasive problems in outdoor recreation and tourism, causing inefficient resource use, loss of profit potential, strain on social and ecological carrying capacities, and administrative scheduling difficulties. This study sought to investigate the extent to which recreation use might be shiftedfrom peak to off-peak periods. The study method was a survey of campers in the Vermont State Park system to test their reaction to a number of planning and management actions designed to alter their camping activity over time. Substantial potential was found for shifting camping activity from peak to off-peak periods, with differential fees, altering opening and closing dates, and location of parks closer to population centers showing the greatest potential effectiveness. Summer weekdays appear to be the easiest off-peak period to which use might be shifted followed by fall, spring, fall and spring combined, and winter. Potential target markets are identified for use redistribution efforts based on work/leisure patterns, stage of family life cycle, residency, and type of recreation activities engaged in.