bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics and outcome of 90 cases of fetal omphalocele
Authors: Brantberg A. , Blaas H.‐G. K. , Haugen S. E. , Eik‐Nes S. H.
Published: September 2005

Objective

The aim of this study was to describe the outcome of a case series of fetuses with omphalocele.

Methods

Ninety fetuses with omphalocele at the National Center for Fetal Medicine (NCFM) between January 1985 and January 2004 were followed from the time of prenatal diagnosis. Follow‐up times ranged from 6 months to 17 years. Omphaloceles were subdivided into epigastric, central and hypogastric types based on their location on the abdominal wall.

Results

There were 58 central and 32 epigastric omphaloceles. Abnormal karyotype was found in 40/58 (69%) of the central and in 4/32 (12.5%) of the epigastric omphaloceles. Trisomy 18 was the most frequent abnormality associated with omphalocele. Among the fetuses with normal karyotype, 89% of the central and 71% of the epigastric cases had other anomalies. 38 (66%) of the fetuses with central omphalocele were terminated and 12 (21%) died during pregnancy or after delivery. 11 (34%) of the fetuses with epigastric omphalocele were terminated and eight (25%) died during pregnancy or after delivery. Of the 90 cases followed from the time of diagnosis there were 21 (23%) survivals. Of eight survivals with central omphalocele, only two were considered healthy while six had other anomalies and/or substantially impaired development. Of 13 survivals with epigastric omphalocele, six were considered healthy and seven had other anomalies and/or substantial impairment.

Conclusions

Fetal central and epigastric omphaloceles may be different entities: central omphaloceles are more strongly associated with abnormal karyotype (69%) than are epigastric omphaloceles (12.5%). The outcome of fetuses with omphalocele is poor irrespective of the type of omphalocele, with only eight of the 90 (9%) being alive and healthy at present. The results emphasize the importance of identifying both those fetuses with a potentially good prognosis and favorable outcome and those which are likely to have a fatal outcome. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Effects of maternal hyperoxia with and without normocapnia in uteroplacental and fetal Doppler studies
Authors: Simchen M. J. , Tesler J. , Azami T. , Preiss D. , Fedorko L. , Goldszmidz E. , Fisher J. , Kingdom J. , Slorach C. , Hornberger L. K.
Published: September 2005

Objective

One hundred percent oxygen is given in pregnancy to improve fetal oxygenation, yet has been shown in both animal and human studies ex utero to increase cerebral vascular resistance. Adjusting end‐tidal pCO2 (ET‐pCO2) levels to normocapnic levels during hyperoxygenation offsets this effect in non‐pregnant individuals. We aimed to evaluate the effect of maternal hyperoxygenation with and without maintaining normocapnia on the fetal and uteroplacental circulations in healthy near‐term human pregnancies.

Methods

Eight healthy pregnant women, serving as their own controls, sequentially breathed room air, breathed 100% oxygen, and underwent normocapnic hyperoxygenation (NH) in a three‐phase experiment involving a tight‐fitting facemask. Each phase lasted 10–15 min. After steady state had been reached, peak velocities and pulsatility index (PI) values were obtained from the uterine, umbilical and fetal middle cerebral arteries (MCA) by color/pulsed Doppler. In addition, maternal ventilation and ET‐pCO2 were monitored.

Results

One hundred percent oxygen induced maternal hyperventilation and hypocapnea. Uterine artery PI and peak systolic velocities were stable during 100% oxygen. In contrast, during NH uterine artery PI values decreased by 21% (P = 0.04). Umbilical artery PI and peak velocities were stable during 100% oxygen; PI increased by 16% during NH (P = 0.056), with no change in peak velocities. Peak MCA velocities decreased by 8% during 100% oxygen, and by 9.6% during NH, while MCA‐PI decreased by 13% during 100% oxygen and by 21% during NH (P = 0.06).

Conclusions

Maternal and fetal circulations exhibit divergent responses to 100% oxygen and NH. While no change is observed in the uteroplacental circulation on 100% oxygen, decreased resistance and increased flow velocity are evident during NH. Increased umbilical artery PI during NH with no change in absolute velocities may suggest a reduction in fetoplacental blood flow. Maintaining normocapnia during hyperoxygenation does not appear to beneficially influence the circulation of the near‐term human fetus as it does in non‐pregnant individuals. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of fetal hydrometrocolpos secondary to a cloacal anomaly by magnetic resonance imaging
Authors: Hayashi S. , Sago H. , Kashima K. , Kitano Y. , Kuroda T. , Honna T. , Nosaka S. , Nakamura T. , Ito Y. , Kitagawa M. , Natori M.
Published: September 2005

Fetal female urogenital anomalies are often difficult to evaluate by ultrasonography, especially in late gestation. We report a case of fetal hydrometrocolpos detected at 35 weeks of gestation. Ultrasonography revealed a large retrovesical septate hypoechogenic mass in the fetal abdomen, however the sonographic findings were inconclusive. Magnetic resonance imaging (MRI) confirmed that the abdominal mass was fluid‐filled with a mid‐plane septum in the midline posterior to the bladder, and showed a connection to the dilated uterus that was duplicated. These findings were consistent with a diagnosis of hydrometrocolpos with septate vagina and uterus didelphys. The neonate showed abdominal distension, ambiguous genitalia and anal atresia with a single perineal opening. Hydrometrocolpos was secondary to a urethral type of cloacal anomaly. Aspiration of the mass and a colostomy were performed on the first postnatal day, followed by anorectoplasty at 19 months of age. MRI is a useful complementary tool for assessing fetal urogenital anomalies when ultrasonography is inconclusive. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Transdermal HRT and Doppler findings in normotensive and hypertensive postmenopausal patients
Authors: Persico N. , Mancini F. , Artini P. G. , de Iaco P. , Volpe A. , de Aloysio D. , Battaglia C.
Published: September 2005

Objective

To evaluate the effects of transdermal hormone replacement therapy (HRT) on plasma viscosity, serum levels of thromboxane B2 (TXB2) and vascular impedance in the uterine, bladder wall, internal carotid and ophthalmic arteries in normotensive and hypertensive postmenopausal patients.

Methods

Thirty postmenopausal patients underwent continuous estradiol transdermal supplementation at a dose of 50 µg/day and 12‐day courses of medroxyprogesterone acetate 10 mg/day every 2 months. The women were divided into two groups according to their blood pressure: normotensive women (Group 1, n = 14) and hypertensive subjects (Group 2, n = 16). Before starting HRT and after 6 months of therapy, the patients underwent: transvaginal ultrasonographic examination of the pelvic organs; Doppler examination of the blood flow velocities in the uterine, bladder wall, internal carotid and ophthalmic arteries; and analysis of plasma viscosity and plasma TXB2.

Results

After 6 months of HRT plasma viscosity had decreased in both groups (mean reduction in Group 1, (14 ± 1)%, P = 0.005; mean reduction in Group 2, (10 ± 1)%, P = 0.005) as had the TXB2 levels (mean reduction in Group 1, (93 ± 2)%, P < 0.001; mean reduction in Group 2, (92 ± 3)%, P < 0.001). The mean percentage reduction in plasma viscosity was smaller in hypertensive women than in normotensive women (P < 0.05). There was also a significant reduction in vascular impedance in the uterine artery (mean reduction in Group 1, (16 ± 1)%, P = 0.005; mean reduction in Group 2, (19 ± 1)%, P = 0.005), the bladder wall arteries (mean reduction in Group 1, (23 ± 2)%, P = 0.005; mean reduction in Group 2, (18 ± 1)%, P = 0.005), the internal carotid artery (mean reduction in Group 1, (25 ± 1)%, P = 0.005; mean reduction in Group 2, (26 ± 1)%, P = 0.005) and the ophthalmic artery (mean reduction in Group 1, (24 ± 2)%, P = 0.005; mean reduction in Group 2, (16 ± 1)%, P = 0.005). The percentage reduction in vascular impedance did not differ significantly between the two groups.

Conclusions

Our results show that transdermal HRT is effective in reducing plasma viscosity, TXB2 levels and vascular impedance in the peripheral and central vessels both in normotensive and hypertensive postmenopausal patients. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Transvaginal sonographic features of peritoneal carcinomatosis
Authors: Savelli L. , De Iaco P. , Ceccaroni M. , Ghi T. , Ceccarini M. , Seracchioli R. , Cacciatore B.
Published: September 2005

Objectives

Peritoneal carcinomatosis involves the dissemination of intra‐abdominal tumor tissue often associated with gynecological malignancies. The objective of this study was to describe the transvaginal sonographic appearance of this condition.

Methods

The data of 60 patients with surgically and histologically proven peritoneal carcinomatosis were analyzed. Transvaginal sonograms performed within 7 days of admission to the operating theater were re‐evaluated in order to identify the sonographic features associated with peritoneal carcinomatosis.

Results

Carcinomatosis was revealed in 53/60 cases (88%) by the presence of hypoechoic nodules attached to the peritoneum and visible on transvaginal sonography (TVS). The pouch of Douglas was the site most frequently involved. Power Doppler sonography showed the presence of blood vessels in 48 (91%) of these metastases. Ascites was found in 50 (83%) women. An adnexal mass suggestive of being the primary tumor was present in only 41 women (68%).

Conclusions

Peritoneal carcinomatosis has typical features on TVS and, in the vast majority of cases, its genital origin can be correctly hypothesized. Power Doppler sonography strengthens the diagnosis by showing vascularity of the peritoneal implants. In a patient with a known pelvic malignancy or whenever peritoneal carcinomatosis is suspected, TVS can give useful information in order to better assess the presence and extension of metastatic nodules within the abdominal cavity. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Ventricular remodeling in Loeffler endocarditis: Implications for therapeutic decision making
Authors: Lofiego Carla , Ferlito Marinella , Rocchi Guido , Biagini Elena , Perugini Enrica , Branzi Angelo , Rapezzi Claudio
Published: September 2005

Background:

Little is known about the morphological and functional evolution of ventricular abnormalities in Loeffler endocarditis.

Methods and Results:

We describe 5 patients, including 3 with long‐term echocardiographic follow‐up, in whom apical obliteration due to fibro‐thrombotic thickening of the endocardium showed favorable patterns of evolution. In one patient there was almost complete resolution of the obliterative process with consequently increased effective ventricular volume. In two patients formation of a flow‐passage in the fibrocalcific apical ‘floor’ between the main medioventricular cavity and the apical chamber, leading to a ‘double‐chambered’ left ventricle was observed.

Conclusions:

Medical therapy and appropriate anticoagulation, can induce favorable long‐term ventricular remodeling in Loeffler endocarditis.
Patients' knowledge and beta blocker treatment improve prognosis of patients from a heart failure clinic
Authors: Lainscak Mitja , Keber Irena
Published: September 2005

Background:

Several studies have shown improvement of prognosis in patients managed in heart failure (HF) clinics. However, the value of the individual management components is not well established.

Aim:

To assess the prognostic value of pharmacological treatment and patient's knowledge in patients receiving care in a HF clinic.

Methods and results:

In our prospective cohort study we followed 115 patients (50 from an HF clinic and 65 receiving usual care) for at least 12 months. Knowledge was assessed using a Patient Knowledge Questionnaire (PKQ). During a median follow‐up of 561 days, fewer patients from the HF clinic died or were rehospitalized due to HF than those receiving usual care (42% vs. 65%, p=0.016). The prescription rates of ACE inhibitors (94% to 98%) and beta blockers (40% to 94%) increased in the patients from the HF clinic. In these patients the PKQ score also increased from 4.8 (1.5) to 7.9 (1.3), p<0.001. In the Cox proportional hazard model, treatment with beta blockers at ≥50% of the target daily dose (Hazard Ratio [HR] 0.3, 95% Confidence Interval [CI] 0.10—0.95) and a PKQ score <7 (HR 3.92, 95% CI 1.39—11.03) predicted prognosis in the patients from the HF clinic.

Conclusions:

Patient management in the HF clinic reduced the incidence of death or of HF rehospitalization. Poor prognosis of patients receiving care in the HF clinic was predicted by poor patient knowledge and underdosing with beta blockers.
Increased circulating endothelial cells in acute heart failure: Comparison with von Willebrand factor and soluble E‐selectin
Authors: Chong Aun Yeong , Lip Gregory Y.H. , Freestone Bethan , Blann Andrew D.
Published: September 2005

Background:

Circulating endothelial cells (CECs) in the peripheral blood, probably representing the most direct evidence of endothelial cell damage, are increased in myocardial infarction, unstable angina and critical limb ischaemia. As chronic heart failure is also associated with endothelial abnormalities, we hypothesised that CECs are raised in acute heart failure and that they would correlate with plasma indices of endothelial perturbation, that is, von Willebrand factor (vWf) and soluble E‐selectin.

Methods:

We studied 30 patients with acute heart failure (venesected within 24 h of emergency hospital admission), 30 patients with chronic stable heart failure (venesected as out‐patients, all patients in sinus rhythm with ejection fraction ≤40%) and 20 healthy controls. CECs were quantified using epifluorescence microscopy after CD146‐immunomagnetic separation and phenotyped by streptavidin/biotin immunocytochemistry. Citrated plasma was analysed for soluble E‐selectin and vWf by ELISA.

Results:

Levels of CECs, vWf and soluble E‐selectin were significantly higher (all p<0.01) in patients with heart failure compared to controls, with no significant differences between acute and chronic heart failure. CECs correlated with plasma vWf (p<0.0001) and soluble E‐selectin (p=0.022) but not ejection fraction or NYHA class. In multiple regression analysis, heart failure was the only independent predictor of raised CECs (p<0.0001). Immunoperoxidase‐defined surface expression of CD34, CD45 and CD36 by CECs was <2%, 0% and 8%, respectively.

Conclusion:

CECs, a possibly heterologous population, may be used as a novel measure of endothelial damage in acute heart failure and may have implications for the thrombotic risk associated with acute and chronic heart failure and prognosis in this condition.
Predicting peak oxygen uptake from 6‐min walk test performance in male patients with left ventricular systolic dysfunction
Authors: Ingle L. , Goode K. , Rigby A.S.R. , Cleland J.G.F. , Clark A.L.
Published: September 2005

Background:

In patients with left ventricular systolic dysfunction (LVSD), peak oxygen uptake (pV̇O2) has strong predictive power for mortality, and can be used to guide management. However, many patients cannot tolerate standard test protocols. The 6‐min walk test (6‐MWT) is often used to estimate functional capacity due to its simplicity, cost effectiveness and familiarity to patients with LVSD. The relationship between 6‐MWT performance and pV̇O2 is not certain, but if closely related could allow substitution of an expensive and cumbersome test for a cheaper and more familiar one.

Methods and results:

120 male patients with LVSD (LVEF <40%; (mean±S.D.) age 68±13 years; BMI 28±5) performed, in random order, a maximal incremental treadmill exercise test with metabolic gas exchange measurements to derive peak oxygen consumption (pV̇O2=19.8±5.8 mL·kg·1·min·1), and a standardised 6‐MWT (308±142 m; r=0.44; P=0.00001). In multivariate models including demographic data, resting blood pressure and heart rate, spirometry, routine blood samples, and walk distance, five variables were independently predictive of peak oxygen consumption. pV̇O2 = 11.92+(1.48×FEV1(L))+(1.12×haemoglobin (g dl−1))+(0.016×distance walked (m))−(0.33×BMI)−(0.11×age (years)). This equation accounted for 48% of the variation in pV̇O2.

Conclusions:

Using these five simple variables, peak oxygen consumption can be estimated with moderate accuracy. In clinical practice, however, when an estimate of peak oxygen consumption is required, incremental exercise testing with metabolic gas exchange measurements cannot be avoided in male patients with LVSD. Further work is needed to assess the relation between estimated pV̇O2 and outcome.
Maximum oxygen uptake corrected for skeletal muscle mass accurately predicts functional improvements following exercise training in chronic heart failure
Authors: LeMaitre John P. , Harris Stuart , Hannan Jim , Fox Keith A.A. , Denvir Martin A.
Published: September 2005

Background:

Skeletal muscle mass and peak oxygen uptake are important predictors of functional status and outcome in patients with stable chronic heart failure.

Aims:

To assess changes in skeletal muscle mass and peak oxygen uptake following an exercise training program.

Methods:

Thirty‐six patients with moderate stable chronic heart failure were randomly allocated to either a bicycle ergometer (bike) or functional electrical muscle stimulators (FES) applied to quadriceps and gastrocnemius muscles to be used daily for six weeks. Dual‐energy X‐ray absorptionometry (DEXA) scanning was performed before and after training along with symptom limited cardiopulmonary exercise test, quadriceps strength and fatigue resistance, and 6‐min walk test.

Results:

Both exercise modalities resulted in improvements in treadmill exercise time, leg strength, 6‐min walk test and peak oxygen uptake per kilogram of skeletal muscle. Despite significant improvements in functional capacity, there were no significant changes in body composition for total skeletal muscle mass, leg muscle mass or total body fat content. Skeletal muscle mass was strongly predictive of maximum oxygen uptake at baseline (r=0.61, p<0.001) and after exercise training (r=0.68, p<0.001).

Conclusions:

In moderate stable chronic heart failure, exercise training using bicycle ergometer or FES results in favourable qualitative rather than quantitative changes in skeletal muscle. Correction of maximum oxygen uptake for skeletal muscle mass rather than total body mass is a more sensitive measure of changes associated with exercise training.
Geographic variation of golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella) in the North Atlantic based on otolith shape analysis
Authors: Stransky Christoph
Published: September 2005

The unresolved interrelationships of North Atlantic redfish stocks have prevented adaptive fisheries assessment and management in the past. Otolith shapes of golden redfish (S. marinus) and deep-sea redfish (S. mentella) were analysed for geographic variation within the entire distribution range in the North Atlantic, in order to evaluate this technique for stock separation. Multivariate analysis of elliptical Fourier shape descriptors revealed high similarity of S. marinus within the central North Atlantic areas (West and East Greenland, Iceland) that were relatively well separated from the Flemish Cap and Barents Sea samples. A similar separation of the Barents Sea area was also observed for S. mentella, whereas the western (Flemish Cap, Davis Strait) and central areas were overlapping to a greater extent. The overall classification rate given by discriminant analysis was poor for both species (<50%) but increased to 72–74% by combining sampling areas to regions (west, central, east). Geographic variation in otolith shapes of both redfish species suggests a separation of the Northeast Arctic stocks (Barents Sea) of both species from the other redfish stocks assessed within ICES and NAFO, whereas similarities observed for the highly migratory S. mentella give reason for integrated management of demersal and pelagic occurrences of this important fisheries resource that straddles the ICES/NAFO boundaries.
Mri ‘Magic Angle’ Imaging of Finger Tendons
Authors: LAMBE G. , COUTTS G. , MCARTHUR P. , DANGERFIELD P. H.
Published: September 2005

The value of using the technique of magic angle MR imaging to demonstrate finger tendons is explored. Images of fresh frozen cadaveric specimens are presented and the structures that can be visualized in the finger are described. The results suggest that magic angle MR imaging may be a useful non-invasive technique of visualizing the details of the tendons and their surrounds in the hand.
Optimization of volunteer labor assignments
Authors: Sampson Scott E.
Published: September 2005

Labor is a crucial resource in most organizations. In not‐for‐profit, public, and government services, it is common for labor to include unpaid volunteers. This article demonstrates how the volunteer labor assignment (VLA) problem is markedly different from traditional labor assignment (TLA) problems such as labor scheduling. One core difference pertains to the cost structure of labor, where TLA problems seek to minimize labor costs, yet labor costs for volunteers are usually trivial. Another difference is the assumed size of the labor pool: TLA typically assumes sufficient labor to cover task requirements, whereas the VLA labor pool is limited by the number of volunteers that can be recruited. These and other distinctions coming from the volunteerism literature are described and confirmed with empirical data. One important finding is that volunteers who were not utilized had a reduced propensity to volunteer in the future. These VLA distinctions are incorporated into an integer goal program. Empirical data are used to demonstrate how VLA assumptions produce solutions that are significantly different from solutions coming from TLA assumptions. Sensitivity analysis is described, as are applications in other VLA contexts.
the role of hydraulic circulatory duplicators in the study of surgical operations for complex congenital cardiac diseases
Authors: kull silvia , gervaso francesca , soldani giorgio , bedini remo , luisi vincenzo stefano
Published: September 2005

a hydraulic circulatory duplicator is a hydraulic circuit, closed or open that physically reproduces one human district, along with the effects of any connected apparatus, on local fluid dynamics. such hydraulic circulatory duplicators are usually made up of rigid or deformable pipes, pressure loss generators, such as valves or sponge elements, compliant elements such as a pneumatic room, elastic elements, pumping elements, which may be centrifugal, axial, or roller, and tanks. all the elements are connected by joints. the systems are completed by transducers of pressure or flow, and systems for visualising flow or measuring other parameters of interest.
a study of the fontan circulation and ventricular energetics based on a model
Authors: ripoli andrea , berti sergio , glauber mattia , vanini vittorio , luisi vincenzo stefano , biagini andrea
Published: September 2005

patients with congenitally malformed hearts characterised by a functionally single ventricle are currently treated using several procedures that bypass the right heart, such as the fontan and hemi-fontan operations, the bidirectional cavopulmonary anastomosis, and the total cavopulmonary connection. all these options are based on the procedures introduced for palliative correction of tricuspid atresia by fontan and baudet in 1971. introduced with the purpose of reducing the pre-operative volume overload, the surgical task mainly consists of separating the pulmonary from the systemic circulation. irrespective of the specific operation performed, we can call the resulting circulation the fontan circulation.
the effect of the position of an additional systemic-to-pulmonary shunt on the fluid dynamics of the bidirectional cavo-pulmonary anastomosis
Authors: gervaso francesca , kull silvia , pennati giancarlo , migliavacca francesco , dubini gabriele , luisi vincenzo s.
Published: September 2005

the bidirectional cavo-pulmonary anastomosis is a well-established palliative procedure for patients with a functionally univentricular circulation. it is usually considered one step in preparation for fontan procedure, but it may be performed as a long-term palliation for patients deemed to be at high-risk. in this subset of patients, a valuable surgical option could be to add, or maintain, an additional source of flow of blood to the lungs, either derived from a patent but banded trunk or one protected by native pulmonary stenosis, or a systemic-to-pulmonary arterial shunt. the risk and benefits of providing an additional source of pulmonary flow after construction of a bidirectional cavopulmonary anastomosis are strongly debated. in terms of benefit, the arterial saturation of oxygen is increased due to the greater ratio of pulmonary-to-systemic flow, arteriovenous fistulas are prevented and, as a consequence of the arterial pulsatile flow, the pulmonary arteries are stimulated to grow. the most significant drawbacks are volume overload of the functionally single ventricle, and higher pressures compared to an isolated bidirectional cavopulmonary anastomosis.
the patterns of flow in the total extracardiac cavopulmonary connection
Authors: amodeo antonio , grigioni mauro , d'avenio giuseppe , daniele carla , di donato roberto m.
Published: September 2005

more than 30 years ago, fontan and baudet proposed bypass of a dysfunctional right ventricle by connecting the pulmonary arteries directly to the right atrium, the so-called atriopulmonary anastomosis. since then, much experience has been accrued in the field of the functionally univentricular circulation. the proposed connections have been subjected to several modifications, aiming towards minimizing the losses of energy in the cavopulmonary system, and thereby improving the clinical outcomes. a remarkable improvement was achieved with the introduction of the concept of the total cavopulmonary connection, specifically the combination of a bi-directional glenn anastomosis with a tubular intracardiac extension from the inferior caval venous to the pulmonary arteries. this design was shown to avoid the dissipation of energy associated with the swirling patterns seen in the traditional atrio-pulmonary anastomosis.
the partial cavo-pulmonary circulation with an additional source of pulmonary flow. an alternative to the total cavo-pulmonary circulation in patients with a functionally single ventricle
Authors: sidi daniel
Published: September 2005

most paediatric cardiologists think that the optimal treatment for patients with functionally single ventricle is the relatively early construction, at from 2 to 7 years of age, of the total cavo-pulmonary circulation. this approach is based on the desire to produce an acyanotic child, such an outcome fostering the belief that the patient is cured. when using this therapeutic approach, the total connection is usually preceded by earlier creation of a partial connection, achieved by creating a bi-directional anastomosis between the superior caval vein and the right pulmonary artery at the age of from 3 to 9 months, without providing additional flow of blood to the lungs. this leads to severe cyanosis by the age of 3 years, when the flow increases in the inferior caval vein, and is the signal for early completion of the total connection. in this policy, the absence of additional flow to the lungs is justified by the fear of altering the ventricular function essential for the success of the total connection, because of the volume, and eventually the pressure, overload of the additional flow on the functionally single ventricle,which may impair its compliance and/or contractility, or be responsible for atrioventricular valvar regurgitation. these alterations in myocardial functions would then contraindicate, or increase, the mortality and morbidity of the total connection, producing deterioration in its long-term results.
the functionally univentricular circulation in the norwood procedure: from analysis of fluid dynamics to surgical procedures
Authors: napoleone carlo pace , gargiulo gaetano
Published: September 2005

the norwood procedure and its modifications have become the most commonly used surgical procedures for patients with hypoplastic left heart syndrome. many efforts have been made to understand the fluid dynamics of the norwood circulation, with the major impetus coming from the lumped-parameter model described by migliavacca et al. in this model, a large number of variables have been analysed to understand their effect on the norwood circulation. in the clinical setting, some of these parameters can be influenced by the surgeon during the operation. the shunt has been demonstrated to be the critical element in regulating the pulmonary and systemic flows, with the goal of the surgeon being to obtain balanced flows. in order to do this, it is possible to influence the flow through the shunt in three ways:

by augmenting the pressure of perfusion of the shunt, with a suboptimal aortic reconstruction that can leave some residual pressure gradient. this can work like an increment of systemic vascular resistance;

by varying the size of the shunt;

by varying the type of architecture of the shunt, since flow through the shunt is dependent on the site of anastomosis, the angle with the vessels, and so on.

in order to validate or verify the results obtained from the lumped-parameter model, we have reviewed our experience with the norwood procedure since 1992.
Paleoseismology of deep‐sea faults based on marine surveys of northern Okushiri ridge in the Japan Sea
Authors: Okamura Yukinobu , Satake Kenji , Ikehara Ken , Takeuchi Akira , Arai Kohsaku
Published: September 2005

The eastern margin of the Japan Sea is an incipient convergent margin characterized by distributed active faults and large‐scale earthquakes. To evaluate the earthquake potential of the northern margin, the source area of the 1940 Shakotan–Hanto‐oki earthquake (M7.5) was reexamined, and the earthquake recurrence interval was estimated by combining bathymetric, seismic, and dive survey data with a tsunami simulation. Seismic profiling clarified that five anticlines have formed in and around this source area during the last 1.8 million years. The balanced cross section of one anticline supports that thrust faults extend to the base of the upper brittle crust at about 11 km depth and total slip is about 850 m. Dive surveys identified fresh collapses along the forelimbs of two anticlines. Inversion of observed tsunami waveforms to estimate the slip distribution suggests that these two anticlines were the sources of the 1940 earthquake. The other three anticlines may be seismic gaps. The dive surveys collected debris layers, possible records of paleoearthquakes, in muddy sediments. From the rate of muddy sediment deposition around the anticlines the minimum recurrence interval of earthquakes was estimated to be about 1100 years. From structural modeling the average interval was about 6400 years, assuming that fault slip started 1.8 million years ago and 3 m of slip occurred during each earthquake. Taking into account the above results and the instantaneous plate convergent rate between the Okhotsk and Amurian plates, the recurrence interval was inferred to be 1100 to a few thousand years.
Crustal flow beneath Iceland
Authors: Jones S. M. , Maclennan J.
Published: September 2005

Theoretical and experimental studies indicate that when oceanic crust is hotter than about 800°C, variations in crustal thickness drive lower crustal flow. We investigate the nature of crustal flow beneath Iceland, where zero‐age crust varies in thickness from under 20 km to over 40 km over a distance of 100 km and temperatures exceed 1000°C below depths of a few kilometers. We model the regional characteristics of crustal flow using the two‐dimensional channel flow equation with depth‐dependent viscosity. The model predicts the observed decay in crustal thickness contrasts between zero‐age and off‐axis crust on shore Iceland and development of a sharp Moho step as the plate moves away from the rift axis. These features become locked in place as plate cooling increases the viscosity. Observations are best matched by model predictions when the solidus viscosity is of order 1018 Pa s, in agreement with viscosity estimates from deformation rates associated with deglaciation and plate boundary processes. Crustal flow acts to erase the crustal thickness memory of ridge‐plume interaction, so that maps of Icelandic crustal thickness can be used neither to derive a detailed plume flux history nor to test in detail whether the Iceland Plume center is fixed relative to other hot spots. Crustal flow beneath Iceland is an unusually clear example of the kind of flow postulated to explain continental phenomena including exhumation of metamorphic core complexes and associated development of low‐angle detachments within extensional terrains and sharp‐edged plateau topography in major collisional belts.
Energy and momentum dissipation through wave breaking
Authors: Zhang Shuwen , Yuan Yeli
Published: September 2005

Wave breaking plays an important role in air‐sea interaction. Laboratory and field measurements suggest that the wave field dissipation can be significantly enhanced by wave breaking and acts as a source of energy for generating current and entraining air against the effect of buoyancy forces. In the present study, a breaking wave model is formulated by taking the acceleration threshold value of −g/2 as breaking criterion, and the statistics of breaking waves, such as breaking wave coverage per unit time, and the volume of breaking water per unit area of wave surface per unit time are estimated. Statistical models are also developed to assess energy and momentum dissipation through wave breaking. It is found that the energy and momentum dissipation rates decay as k−3 and k−2.5, respectively. The energy loss is mainly due to wave components at frequencies higher than the spectral peak frequency. Though energy loss due to wave components at frequencies lower than the spectral peak frequency is found, these wave components do not significantly lose energy after the breaking. The energy loss, when expressed as phase speed cb of breaking waves, is mainly in the range 0.20 cp < cb < 0.90 cp, where cp is the dominant wave phase speed, and the energy dissipation rate falls off rapidly toward shorter scales. This offers no support for the hypothesis of a “Kolmogorov cascade” in wind‐generated waves analogous to that in turbulence, with energy input from the wind at large scales and dissipation from the waves at the smallest scales. It is also demonstrated that, compared with empirical formula results, our model of energy (or momentum) dissipation rate lies between those models that estimate by empirical formula the rate of energy (or momentum) loss from a breaker with proportional coefficients 0.0085 and 0.0007. In addition, the peak frequency of our model energy (or momentum) dissipation rate downshifts to the lower‐frequency band as wind speed increases, whereas the peak of the empirical formula remains at the same frequency.
Reduction in tropical rainfall diurnal variation by global warming simulated by a 20‐km mesh climate model
Authors: Kitoh Akio , Arakawa Osamu
Published: September 2005

A time‐slice global warming experiment was performed with a very high‐resolution (20‐km mesh) atmospheric general circulation model. Due to increased horizontal resolution, land‐sea distribution over the Indonesian Maritime Continent is well represented. A clear contrast in precipitation change at the end of the twenty‐first century is found over Borneo Island and the Java Sea: over the ocean morning precipitation decreases and evening precipitation increases, while over the island morning precipitation increases, resulting in reduced amplitude of rainfall diurnal variation over both land and ocean. Weakened land‐sea breeze circulation by global warming due to larger nighttime temperature increases over land than during the day contributes to this decreased rainfall diurnal variation.
Waves encircling the summer southern pole of Mars observed by MGS TES
Authors: Fukuhara Tetsuya , Imamura Takeshi
Published: September 2005

Distinct atmospheric disturbances with zonal wave number 1 were found in the summer southern polar region of Mars using the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) retrieved temperatures provided by NASA. Our investigations show that the polar disturbances exist during summer (Ls = 250°–270°) in three consecutive Martian years. These disturbances have phase structures tilted westward with height, and connected with near‐surface temperature anomalies whose maxima and minima are largely fixed to those of the surface temperature associated with the axially asymmetric polar cap. Such a wave structure is consistent with stationary planetary waves that are forced by axially asymmetric surface temperature anomaly and propagate upward in weak eastward winds flowing over the polar cap.
Measurements of the ion concentrations and conductivity over the Arabian Sea during the ARMEX
Authors: Siingh Devendraa , Pawar S. D. , Gopalakrishnan V. , Kamra A. K.
Published: September 2005

Measurements of the small‐, intermediate‐, and large‐ion concentrations and the atmospheric electric conductivity of both polarities have been made over the Arabian Sea on four cruises of ORV Sagarkanya during the Arabian Sea Monsoon Experiment (ARMEX) during the monsoon and premonsoon seasons of 2002 and 2003. Seasonally averaged values of the total as well as polar conductivity are much higher during the monsoon than premonsoon season. Surprisingly, however, the concentration of small ions is less and those of large and intermediate ions are more during the monsoon than premonsoon season. The diurnal variations observed during the premonsoon season show that the nighttime small ion concentrations are about an order of magnitude higher than their daytime values. On the contrary, the daytime concentrations of the intermediate and large ions are much higher than those of their nighttime values. No such diurnal variations in ion concentrations are observed in monsoon season. Also examined are the variations in ion concentrations of different categories with distance from the coastline in different seasons and the ion concentration changes associated with the precipitation of various types that occurred over ORV Sagarkanya. It is sufficient to invoke the ion‐aerosol attachment process to explain our premonsoon observations. However, the generation of highly charged large ions by the bubble‐breaking process caused by the wave breaking due to strong southwesterly surface winds (10–12 m s−1) over the Arabian Sea is postulated to explain the monsoon season observations.
Meteorological indices for Asian outflow and transpacific transport on daily to interannual timescales
Authors: Liang Qing , Jaeglé Lyatt , Wallace John M.
Published: September 2005

We examine the variability of Asian pollution outflow to the western Pacific and its associated long‐range transport to the northeast (NE) Pacific between 1992 and 2002, using a global simulation of carbon monoxide (CO). We develop three new sea‐level pressure indices, which capture variations in transpacific transport on daily to interannual timescales. Our first index, LRT1 (standardized daily pressure anomalies in NE China), is related to the passage of mid‐latitude cyclones in East Asia and captures 14–22% of the variability in the outflow of Asian pollution to the western Pacific. A second index, LRT2 (standardized daily pressure anomalies North of Hawaii), captures 25–32% of the variability in transpacific transport during winter‐spring. Enhanced transpacific transport is characterized by a strong Pacific High displaced to the west of 140°W and a strong low over Alaska, resulting in strong zonal winds in the NE Pacific. The last index, LRT3 (based on monthly SLP anomalies over the North Pacific), identifies stronger than normal Pacific High and Aleutian Low pressure systems, which together result in unimpeded transport across the Pacific during winter and spring. LRT3 captures 42% and 55% of the monthly and interannual variance in transpacific transport, respectively. We find that 1992–1996 and 2002 were below‐average transpacific transport years, while 1998–2000 had unusually strong transpacific transport. By extending our LRT3 time series back to 1948, we find that the strength of transpacific transport projects strongly upon the Pacific/North American (PNA) index, the leading mode of month‐to‐month variability over the Pacific. There appears to be decadal variability in LRT3, with below‐average transpacific transport for 1948–1976 and above‐average transport since 1977.
Roles of transport in the seasonal variation of the total ozone amount
Authors: Miyazaki K. , Iwasaki T. , Shibata K. , Deushi M.
Published: September 2005

Seasonal variations of the meridional ozone transport and their contributions to the total ozone amount are investigated in terms of mass‐weighted isentropic zonal means and eddies of ozone flux. Three‐dimensional data obtained using a chemical transport model are used to estimate transport fluxes. The mean ozone transport decreases the total ozone amount in the tropics and increases it in the extratropics, since the stratospheric poleward ozone transport due to the Brewer‐Dobson circulation is much greater than the lower tropospheric equatorward transport. The mean ozone flux convergence centered near the pole in the Northern Hemisphere has considerable seasonal variation with a maximum in late winter. The flux convergence is centered outside of the polar vortex in the Southern Hemisphere, and its seasonal variation is somewhat small. In addition, the Brewer‐Dobson circulation causes a seasonal variation of the tropical divergence, which is greatest in the northern winter. The eddy ozone transport is mostly equatorward in the lower stratosphere and troposphere, since the extratropical downward transport forms the isentropic poleward gradient of the ozone mixing ratio. It decreases the total ozone amount in the extratropics and increases it in the tropics. The eddy transport contributes less to seasonal variation of the total ozone amount; however, a strong poleward eddy transport increases it near the Antarctic in late spring. The transport characteristics are discussed in detail during and after breakdown of the Antarctic polar vortex.
Conversion of NOAA atmospheric dry air CH4 mole fractions to a gravimetrically prepared standard scale
Authors: Dlugokencky E. J. , Myers R. C. , Lang P. M. , Masarie K. A. , Crotwell A. M. , Thoning K. W. , Hall B. D. , Elkins J. W. , Steele L. P.
Published: September 2005

Sixteen mixtures of methane (CH4) in dry air were prepared using a gravimetric technique to define a CH4 standard gas scale covering the nominal range 300–2600 nmol mol−1. It is designed to be suitable for measurements of methane in air ranging from those extracted from glacial ice to contemporary background atmospheric conditions. All standards were prepared in passivated, 5.9 L high‐pressure aluminum cylinders. Methane dry air mole fractions were determined by gas chromatography with flame ionization detection, where the repeatability of the measurement is typically better than 0.1% (≤1.5 nmol mol−1) for ambient CH4 levels. Once a correction was made for 5 nmol mol−1 CH4 in the diluent air, the scale was used to verify the linearity of our analytical system over the nominal range 300–2600 nmol mol−1. The gravimetrically prepared standards were analyzed against CH4 in air standards that define the Climate Monitoring and Diagnostics Laboratory (CMDL) CMDL83 CH4 in air scale, showing that CH4 mole fractions in the new scale are a factor of (1.0124 ± 0.0007) greater than those expressed in the CMDL83 scale. All CMDL measurements of atmospheric CH4 have been adjusted to this new scale, which has also been accepted as the World Meteorological Organization (WMO) CH4 standard scale; all laboratories participating in the WMO Global Atmosphere Watch program should report atmospheric CH4 measurements to the world data center on this scale.
Hydration state and abundance of zeolites on Mars and the water cycle
Authors: Tokano Tetsuya , Bish David L.
Published: September 2005

Recent experimental studies have suggested that zeolites, if present on the Martian surface, could undergo a strong diurnal cycle of hydration and dehydration with possible impact on the atmosphere. This study evaluates this possibility using a global model of hydration/dehydration of two different zeolites (clinoptilolite and chabazite) assuming actual diurnal, seasonal, and geographical temperature variations. If zeolites extensively cover the surface and undergo complete diurnal hydration/dehydration cycles as predicted from the water vapor adsorption isotherms, the resulting water content would be too high in both the surface material and the atmosphere, implying that the abundance of zeolites is low or that zeolites must exist in a more desiccated state. If the zeolite abundance is low with the same hydration behavior, the lowest mean surface water content would occur at the equator, which also does not agree with observations. If substantial hydration/dehydration occurs seasonally rather than diurnally, the latitudinal and seasonal variation of the water content becomes too large and the zeolite abundance would have to vary with season to match the observation, which is also unrealistic. The most realistic scenario is a diurnally and seasonally constant low hydration state of zeolites controlled by the annual maximum surface temperature, in addition to a low abundance. Using these assumptions, the global distribution of the water content in the near‐surface dry layer inferred from Mars Odyssey High‐Energy Neutron Detector (HEND) data can be roughly explained. The best estimate of the zeolite abundance in the surface material to account for the observed water content is, on global average, ∼30% for Ca‐clinoptilolite, ∼35% for Na‐clinoptilolite, ∼55% for K‐clinoptilolite, and ∼15% for chabazite if no other hydrated minerals are present. Putative regional confinement of zeolites to the dust‐rich regions generally worsens the correlation between the modeled and observed water content compared with the scenario with globally uniform zeolite distribution, implying that zeolites may be present in dust‐poor regions as well. In any case, our study shows that the diurnal atmospheric water cycle is unlikely to be affected by zeolites on the Martian surface.
Potential Sex Differences Remain Understudied: A Case Study of the Inclusion of Women in HIV/AIDS-Related Neuropsychological Research
Authors: Fox-Tierney Rachel A. , Ickovics Jeannette R. , Cerreta Carrie L. , Ethier Kathleen A.
Published: September 2005

As an illustration of women's representation in clinical research, a comprehensive literature review of HIV/AIDS-related neuropsychological research was conducted. The goals of this study were to document whether women have been included in (a) HIV-related neurological and neuropsychological research studies; (b) percentages comparable to their representation in the population of persons with HIV/AIDS; (c) studies using numbers sufficient to allow data analyses by sex ( N ≥ 30); and (d) data analyses conducted to examine sex differences. Women were included in half of the studies investigating neurological and neuropsychological manifestations of HIV between 1988 and 1997 (236 studies). However, their representation was inadequate to determine whether there were reliable sex differences in these complications. It is not simply enough to include more women; researchers must also strive to increase the quality of studies to ensure that women's contribution is clinically and empirically relevant.