bluuebunny/crossref_metadata_2025 huggingface dataset:
The evolution of an elliptic vortex ring
Authors: Dhanak M. R. , Bernardinis B. DE
Published: April 2006

The evolution of a vortex ring in an ideal fluid under self-induction from a flat and elliptic configuration is followed numerically using the cut-off approximation (Crow 1970) for the velocity at the vortex. Calculations are presented for four different axes ratios of the initial ellipse. A particular choice is made for the core size and vorticity distribution in the core of the vortex ring. When the initial axes ratio is close to 1, the vortex ring oscillates periodically. The periodicity is lost as more eccentric cases are considered. For initial axes ratio 0·2, the calculations suggest a break-up of the ring through the core at one portion of the ring touching that at another, initially distant, portion of the ring.

Results from quantitative experiments, conducted at moderate Reynolds number with the vortex rings produced by puffing air through elliptic orifices, are compared with the calculations. The agreement is fairly good and it is found that a vortex ring produced from an orifice of axes ratio 0·2 breaks up into two smaller rings. The relevance of the results to the vortex trail of an aircraft is discussed.
The effect of the overtaking disturbance on a shock wave moving in a non-uniform medium
Authors: Chisnell R. F. , Yousaf M.
Published: April 2006

When a shock moves in a non-uniform medium, its motion is influenced both by the non-uniformity ahead of the shock and also by a wave which overtakes the shock. In this paper the overtaking wave is examined in an analytic manner by considering its formation and subsequent propagation. This analysis is then combined with the known ‘freely propagating’ description of the shock motion, in which the overtaking wave is ignored, and results in a description of the shock motion in integral form. For the particular problem of a strong shock propagating in a medium with a power-law density variation, the freely propagating shock law has previously been compared with the available similarity solution. The estimate of the effect of the overtaking wave presented in this paper is shown to provide a significant improvement to the description of the shock motion in this instance.
The intrusion of a density current along the coast of a rotating fluid
Authors: Stern Melvin E. , Whitehead John A. , Hua Bach-Lien
Published: April 2006

When light rotating fluid spreads over heavier fluid in the vicinity of a vertical wall (coast) a boundary jet of width Λ forms, the leading edge or nose of which propagates with speed ĉ along the coast. A certain fraction 8 of the boundary transport is not carried by the nose but is deflected backwards (detrained) and left behind the propagating nose. Theoretical and experimental results for Λ,ĉ, and δ are given for a quasi-equilibrium (constant-ĉ) regime. Over longer time intervals the laboratory observations suggest that the nose slows down and stagnates, whereupon the trailing flow separates from the coast and an intermittent boundary current forms. These processes may be relevant to the mixing of oceanic coastal currents and the maintenance of the mean current.
Laminar condensation on a moving drop. Part 2. Numerical solutions
Authors: Chung J. N. , Ayyaswamy P. S. , Sadhal S. S.
Published: April 2006

In this paper, we investigate the problem of transient laminar condensation on a moving drop by the semianalytical series-truncation method. The objectives are to assess the validity and the accuracy of the matched-asymptotic method employed in Part 1. The fluid flow and thermodynamic variables are expanded as complete series of Legendre polynomials. The resulting transient momentum, energy and species equations are integrated numerically. The numerical scheme basically involves a three-point central difference for the spatial derivatives and a backward difference expression for the temporal derivatives. The finite-difference equations have been solved by the strongly implicit procedure. Good agreement of the fully transient numerical results with the singular perturbation approximation results of Part 1 lends credibility to a quasi-steady treatment of the continuous phase. The computational time requirements for the fully numerical solutions increase with decreasing non-condensable gas mass fraction in the bulk environment.
Simple three-dimensional vortex motions in coflowing jets and wakes
Authors: Perry A. E. , Tan D. K. M.
Published: April 2006

The vortex patterns which occur in coflowing jets and wakes at moderate Reynolds numbers (of order 500) are examined in detail. Flow visualization is used in conjunction with a flying hot-wire system which allows instantaneous velocity vector fields to be rapidly measured and related to the smoke patterns. The structures were made perfectly periodic in time by artificial stimulation. The experiments were therefore completely deterministic. This newly developed data-acquisition technique does not require the use of Taylor's hypothesis for inferring patterns from a fixed streamwise position. It therefore allows the vector fields of rapidly evolving patterns to be produced. It also allows the phenomenon of three-dimensional vortex pairing to be studied. The classification of patterns and conjectured topologies made by Perry & Lim (1978a, b) and the interpretations of Perry, Lim & Chong (1980) and Perry & Watmuff (1981) are examined. In the light of more-detailed measurements, it is found that some of these interpretations require modification.

Vortex ‘skeleton’ models of the patterns are constructed and it is found that the Biot-Savart law gives vector fields which are in reasonable agreement with the experiments. It is also found that the power-spectral density of a periodic array of eddies can be explained in terms of potential flow vortices.
Free vibrations of a drop in partial contact with a solid support
Authors: Strani M. , Sabetta F.
Published: April 2006

Under the assumptions of zero gravity, of negligible viscous effects and of small surface deformations, the problem of the axisymmetric free vibrations of a liquid drop immersed in an outer fluid and in partial contact with a spherical bowl has been analysed. Using the Green function method and expanding the velocity potentials in series of Legendre polynomials, the problem has been reduced to the solution of a single integral equation whose kernel has been expressed in analytical form. It is found that, in comparison with an isolated drop, constrained drops have an additional vibration mode which reduces to a zero-frequency rigid motion as the support size tends to zero, while the remaining ones approach the modes predicted by Lamb for a free drop.

The vibration modes have been numerically calculated for different sizes of the supported surface and compared with the experimental results of Bisch, Lasek & Rodot (1982).
Turbulence spectra from the viscous sublayer and buffer layer at the ocean floor
Authors: Hriss T. M. C. , Caldwell D. R.
Published: April 2006

An experiment conducted on the Oregon continental shelf has provided measurements of velocity fluctuations in the viscous sublayer and buffer layer of the boundary-layer flow. Spectra from the viscous sublayer collapse considerably when scaled as suggested by Bakewell & Lumley (1967), and buffer-layer spectra collapse reasonably well with laboratory spectra when the scaling customarily used in the logarithmic layer is applied. However, in spite of the usefulness of the spectral scaling, the scaled sublayer and buffer-layer spectra from the ocean floor fall below the scaled laboratory spectra in the energy-containing portion of the spectrum, perhaps because the sea floor is not perfectly planar.
Theory of non-propagating surface-wave solitons
Authors: Larraza A. , Putterman S.
Published: April 2006

An incompressible inviscid fluid contained in a channel in a gravitational field admits soliton-like disturbances where the velocity potential depends upon all three coordinates as well as time, yet its centre of mass can be at rest. These solitons were recently discovered by Wu, Keolian & Rudnick. The calculations are carried out with the multiple-scales approach. Consequences of mass conservation and radiation are discussed.
Should sewage be discharged at the water surface or near the bed?
Authors: Smith Ronald
Published: April 2006

The mortality of bacteria in sewage discharges into shallow seas is strongly influenced by light and varies with distance from the free surface. Here a criterion is derived for deciding between the opposing strategies of getting rapid bacterial decay by directing the sewage up to the surface at the sacrifice of initial dilution, or of achieving high initial dilution with a distributed source along the bed perpendicular to the flow direction.
Monocyanopolyynes from a carbon arc in ammonia: about the relative abundance of polyynes series formed in a carbon arc and those detected in the circumstellar shells of AGB stars
Authors: Cataldo Franco
Published: April 2006

Monocyanopolyynes are formed by arcing graphite electrodes in ammonia. This work completes the parallelism existing between the polyynes formed by laser ablation experiments of graphite targets and those produced from the submerged electric arc. In both cases the same products are obtained. The products consist of hydrogen-terminated polyynes if water is present, monocyanopolyynes (mixed with hydrogen-terminated polyynes) if the carbon arc is sparked in acetonitrile or ammonia and dicyanopolyynes if the arc is struck in liquid nitrogen. The mechanism of formation of polyynes in the submerged carbon arc involves essentially neutral species; similar species and pathways may also occur in the circumstellar environment where polyynes have been detected by radioastronomy. It is shown that the relative abundances of the polyynes formed in the submerged carbon arc or in a carbon arc in vacuum decrease by a factor between three and five as the chain length increases by a C2 unit. Exactly the same trend has been observed by radioastronomy both for polyynes and cyanopolyynes in the circumstellar environment around red giants and asymptotic giant branch (AGB) stars. This fact may be a simple coincidence or may suggest that the mechanism of formation of the polyynes in the carbon arc is the same as that occurring in the surroundings of carbon-rich stars.
Sonographische Diagnostik des post-interventionellen Pneumothorax und Seropneumothorax – Prospektive Studie an 100 Patienten
Authors: Reissig  , Kroegel
Published: April 2006

In dieser prospektiven Studie wurde der Stellenwert der transthorakalen Sonographie bei der Diagnostik bzw. beim Ausschluss des Pneumothorax/Seropneumothorax nach transbronchialer Biopsie und Pleuraergussdrainage mittels Pleurakatheter untersucht und mit den Röntgen-Thoraxaufnahmen verglichen. Insgesamt wurden 100 Patienten (38 Frauen, 62 Männner; mittleres Alter 63 Jahre) untersucht, 63 Patienten nach transbronchialer Biopsie und 37 Patienten nach Pleuraerguss-Drainage. Drei Stunden nach der Intervention erfolgte zunächst eine Thoraxsonographie, gefolgt von einer Röntgen-Thoraxaufnahme. Bei einem (1%) der 100 Patienten trat ein post-interventioneller Pneumothorax und bei acht Patienten (8%) ein Seropneumothorax auf. Die Sensitivität, Spezifität und Treffsicherheit der transthorakalen Sonographie bei der Pneumothorax-/Seropneumothorax-Diagnostik betrug 100%. Ein Seropneumothorax konnte röntgenologisch erst auf einer zusätzlich angefertigten seitlichen Röntgenaufnahme im Liegen erkannt werden. Die transthorakale Sonographie ist eine nicht-invasive und strahlenfreie Alternative zum herkömmlichen Vorgehen. Eine Röntgen-Thoraxaufnahme ist weiterhin bei Patienten mit sonographisch diagnostiziertem Pneumothorax (zur Bestimmung der Tiefenausdehnung), bei eingeschränkter sonographischer Beurteilbarkeit (z.B. bei Vorliegen eines Hautemphysems) sowie bei Auftreten einer Diskrepanz zwischen sonographischem und klinischem Befund erforderlich.
Staff experiences of an early warning indicator for unstable patients in Australia
Authors: Green Anna , Allison William
Published: April 2006

The objective of this study is to explore nursing and medical staff's perceptions of a clinical marker referral tool implemented to assist in the early identification of unstable patients in the general surgical and medical ward environment. A descriptive, exploratory survey design was undertaken 6 months after the implementation of a clinical marker referral tool. The target population for the survey was all ward nursing, junior medical staff and intensive care unit (ICU) registrars in a metropolitan tertiary referral hospital in Australia. The survey consisted of open‐ended and closed‐ended questions, as well as statements asking participants to explore their perceptions, attitudes and perceived understanding of the clinical marker referral tool. The surveys were sent to all targeted staff in a personally addressed envelope via the internal mail system. Overall, nursing and medical staff (n = 178) responses were positive to the clinical marker project/tool, offering clear guidelines for staff to respond to the patient's clinical condition and contact the medical staff and the ICU liaison team as appropriate. Furthermore, comments were made in relation to the ICU liaison team acting as a ‘support’ and ‘prompt back‐up’ for nursing staff when needed. However, ward medical staff had reservations with the clinical markers chosen and with ward nurses being able to contact the ICU registrar after hours. Additionally, the ICU registrars commented on an increase to their workload in having to review unstable patients after hours. These results suggest that the ward nurses required additional support and guidance in caring for the unstable patient in the ward which may improve patient outcomes. Further research investigating the less‐favourable responses of the ward medical staff and ICU medical staff is warranted.
Comprehensive health assessments during de‐institutionalization: an observational study
Authors: Lennox N. , Rey‐Conde T. , Cooling N.
Published: April 2006

Background  People with intellectual disability (ID) leaving institutions pass through a transition stage that makes them vulnerable to inadequate health care. They enter into community care under general practitioners (GPs) who are often untrained and inexperienced in their needs. Specifically designed health reviews may be of assistance to both them and their new GPs as they go through that phase.

Methods  This research aimed to investigate the effectiveness of a specially designed health review, the comprehensive health assessment program (CHAP) health review, in a group of adults as they transitioned out of the care of the last institution for people with ID in Tasmania. There were 25 residents reviewed by their GPs.

Results  The CHAP reviews picked up a number of health conditions and stimulated health promotion activities. Some of the findings were: a high number of abnormal Body Mass Indexes (19/23), immunizations given (13/23), vision impairment reported (2/23), mental health issues recorded (4/23) and skin abnormalities described (17/23). There were 22 referrals made to other health professionals (Australian Hearing Service 4, dentists 3, optometrists 3, psychiatrists 2, neurologists 2, ophthalmologist 1, urologist 1, ultrasound 1, mammogram 1, family planning 1, physiotherapist 1, continence nurse 1 and respiratory physician 1). These were in addition to various requests for pathology.

Conclusions  The CHAP health review was effective in identifying a number of health issues in the population of people with ID as they transitioned out of institutional care into the general community.
Functional characterisation of the regulation of CAAT enhancer binding protein alpha by GSK-3 phosphorylation of Threonines 222/226
Authors: Liu H-K , Perrier S , Lipina C , Finlay D , McLauchlan H , Hastie CJ , Hundal HS , Sutherland C
Published: April 2006

Background

Glycogen Synthase Kinase-3 (GSK3) activity is repressed following insulin treatment of cells. Pharmacological inhibition of GSK3 mimics the effect of insulin on Phosphoeno lpyruvate Carboxykinase (PEPCK), Glucose-6 Phosphatase (G6Pase) and IGF binding protein-1 (IGFBP1) gene expression. CAAT/enhancer binding protein alpha (C/EBPα) regulates these gene promoters in liver and is phosphorylated on two residues (T222/T226) by GSK3, although the functional outcome of the phosphorylation has not been established. We aimed to establish whether CEBPα is a link between GSK3 and these gene promoters.

Results

C/EBPα represses the IGFBP1 thymine-rich insulin response element (TIRE), but mutation of T222 or T226 of C/EBPα to non-phosphorylatable alanines has no effect on C/EBPα activity in liver cells (towards the TIRE or a consensus C/EBP binding sequence). Phosphorylation of T222/T226 is decreased by GSK3 inhibition, suggesting GSK3 does phosphorylate T222/226 in intact cells. However, phosphorylation was not altered by treatment of liver cells with insulin. Meanwhile C/EBPα activity in 3T3 L1 preadipocytes was enhanced by mutation of T222/T226 and/or S230 to alanine residues. Finally, we demonstrate that C/EBPα is a very poor substrate for GSK3 in vitro and in cells.

Conclusion

The work demonstrates an important role for this domain in the regulation of C/EBPα activity in adipocytes but not hepatocytes, however GSK3 phosphorylation of these residues does not mediate regulation of this C/EBP activity. In short, we find no evidence that C/EBPα activity is regulated by direct phosphorylation by GSK3.
The appropriateness of gatekeeping in the provision of reproductive health care for adolescents in Lithuania:the general practice perspective
Authors: Jaruseviciene Lina , Levasseur Gwenola
Published: April 2006

Background

Adolescents' consultation of primary health care services remains problematic despite their accessibility. The reproductive health service seeking behavior of adolescents is the object of much research but little is known about how this behavior is influenced by the gatekeeping system. This study aimed to explore general practitioners' perceptions of the appropriateness of gatekeeping in adolescent reproductive health care.

Methods

Twenty in-depth interviews regarding factors affecting adolescent reproductive health care were carried out on a diverse sample of general practitioners and analyzed using grounded theory.

Results

The analysis identified several factors that shaped GPs' negative attitude to gatekeeping in adolescent reproductive health care. Its appropriateness in this field was questionable due to a lack of willingness on the part of GPs to provide reproductive health services for teenagers, their insufficient training, inadequately equipped surgeries and low perceived support for reproductive health service provision.

Conclusion

Since factors for improving adolescent reproductive health concern not only physicians but also the health system and policy levels, complex measures should be designed to overcome these barriers. Discussion of a flexible model of gatekeeping, encompassing both co-ordination of care provided by GPs and the possibility of patients' self-referral, should be included in the political agenda. Adolescents tend to under-use rather than over-use reproductive health services and every effort should be made to facilitate the accessibility of such services.
Combination of celecoxib with percutaneous radiotherapy in patients with localised prostate cancer – a phase I study
Authors: Ganswindt U , Budach W , Jendrossek V , Becker G , Bamberg M , Belka C
Published: April 2006

Background

Current approaches for the improvement of bNED for prostate cancer patients treated with radiotherapy mainly focus on dose escalation. However molecularly targeted approaches may also turn out to be of value. In this regard cyclooxygenase (COX)-2 inhibitors have been shown to exert some anti-tumour activities in human prostate cancer in vivo and in vitro. Although in vitro data indicated that the combination of COX-2 inhibition and radiation was not associated with an increased toxicity, we performed a phase I trial using high dose celecoxib together with percutaneous radiation therapy.

Methods

In order to rule out any increases of more than 20% incidence for a given side effect level 22 patients were included in the trial. Celecoxib was given 400 mg twice daily with onset of the radiation treatment. Risk adapted radiation doses were between 70 and 74 Gy standard fractionation. RTOG based gastrointestinal (GI) and genitourinary (GU) acute toxicity scoring was performed weekly during radiation therapy, at six weeks after therapy and three month after completing radiation treatment.

Results

Generally no major increase in the level and incidence of side effects potentially caused by the combined treatment was observed. In two cases a generalised skin rash occurred which immediately resolved upon discontinuation of the drug. No grade 3 and 4 toxicity was seen. Maximal GI toxicity grade 1 and 2 was observed in 85% and 10%, respectively. In terms of GU toxicity 80 % of the patients experienced a grade 1 toxicity and 10 % had grade 2 symptoms.

Conclusion

The combination of irradiation to the prostate with concurrent high dose celecoxib was not associated with an increased level of side effects.
Renaissance Latin Aristotle Commentaries: Authors N-Ph
Authors: Lohr Charles H.
Published: April 2006

These pages continue the inventory of Renaissance Latin Aristotle Commentaries published in Studies in the Renaissance, XXI (1974), 228-289; Renaissance Quarterly, XXVIII (1975), 689-741; XXIX (1976), 714-745; XXX (1977), 681-741; XXXI (1978), 532–603. The commentaries have been arranged alphabetically according to the author's family name, with a brief biobibliographical note and indication of the manuscripts and printed editions.
DomoSim‐TPC: Collaborative problem solving to support the learning of domotical design
Authors: Redondo Miguel Á. , Bravo Crescencio
Published: April 2006

Domotics is a subject taught in engineering and in technical training and refers to the methods followed to introduce the technology of service automation in housings and buildings. One of the most important aspects while learning this subject is the design of installations to satisfy a set of requirements. In order to design and to test these installations it is necessary to carry out practical works with expensive and dangerous materials. In this situation the use of a computer‐supported collaborative learning environment can be a good complement to facilitate this engineering task and to provide a social dimension of learning by creating group work habits. In this paper, we present a proposal of a teaching model for this discipline and a telematic environment developed to give support to the realization of practical works of domotical design in group. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 9–19, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20062
Nonadiabatic and frictional constant area duct flow: A visual software based simulation for compressible systems
Authors: Ozalp A. Alper
Published: April 2006

Numerical investigation of compressible flows in constant area ducts becomes substantially complicated when the surface roughness and heat flux conditions simultaneously act as independent and considerable boundary conditions that create significant influences on the flow and heat transfer characteristics. This article presents GAS‐DYN v2.0, a specialized software package, capable of handling nonadiabatic and frictional systems with the contribution of a database, developed also by the author, which involves the real time temperature‐dependent gas properties. Results of the presented computational analysis are in harmony with the available literature, which not only indicates the reliability of the package but also points out its adaptability to MSc and PhD level research studies and for the compressible flow system design projects. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 64–75, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20068
Motion vector coding by using representation of norm and angle components
Authors: Shimizu Atsushi , Sagata Atsushi , Kamikura Kazuto , Kobayashi Naoki
Published: April 2006

Since many video coding methods use prediction between motion‐compensated frames, the motion vector must be transmitted. A large amount of code is generated for DCT coefficients for the motion vector. Therefore, prediction is performed from the motion vectors of neighboring blocks and variable‐length coding of the horizontal and vertical components of the prediction error vector is performed to reduce the amount of generated code. However, since this method handles the horizontal and vertical components as independent components, appropriate code assignment for coding the prediction error vector may not be possible. In this paper, the authors propose a method of coding by using norm and angle components to represent the prediction error vector and compare its coding efficiency with the conventional method to show its effectiveness. ©2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(10): 54–62, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20265
Progressive histological damage in liver allografts following pediatric liver transplantation
Authors: Evans Helen M. , Kelly Deirdre A. , McKiernan Patrick J. , Hübscher Stefan
Published: April 2006

The long-term histological outcome after pediatric liver transplantation (OLT) is not yet fully understood.

De novo

autoimmune hepatitis, consisting of histological chronic hepatitis associated with autoantibody formation and allograft dysfunction, is increasingly recognized as an important complication of liver transplantation, particularly in the pediatric population. In this study, 158 asymptomatic children with 5-year graft survival underwent protocol liver biopsies (113, 135, and 64 at 1, 5, and 10 years after OLT, respectively). Histological changes were correlated with clinical, biochemical, and serological findings. All patients received cyclosporine A as primary immunosuppression with withdrawal of corticosteroids at 3 months post OLT. Normal or near-normal histology was reported in 77 of 113 (68%), 61 of 135 (45%), and 20 of 64 (31%) at 1, 5, and 10 years, respectively. The commonest histological abnormality was chronic hepatitis (CH), the incidence of which increased with time [25/113 (22%), 58/135 (43%), and 41/64 (64%) at 1, 5, and 10 years, respectively) (

P

< .0001)]. The incidence of fibrosis associated with CH increased with time [13/25 (52%), 47/58 (81%), and 37/41 (91%) at 1, 5, and 10 years, respectively) (

P

< .0001)]. The severity of fibrosis associated with CH also increased with time, such that by 10 years 15% had progressed to cirrhosis. Aspartate aminotransferase (AST) levels were slightly elevated in children with CH (median levels 52 IU/L, 63 IU/L, and 48 IU/L at 1, 5, and 10 years, respectively), but this did not reach statistical significance compared with those with normal histology. On multivariate analysis, the only factor predictive of chronic hepatitis was autoantibody positivity (present in 13% and 10% of children with normal biopsies at 5 and 10 years, respectively, and 72% and 80% of those with CH at 5 and 10 years, respectively) (

P

< .0001). Four children with CH and autoantibodies, who also had raised immunoglobulin G (IgG) levels and AST greater than 1.5× normal fulfilled the diagnostic criteria for

de novo

autoimmune hepatitis (AIH). Another two were found to be hepatitis C positive. No definite cause for CH could be identified in the other cases.

In conclusion

, chronic hepatitis is a common finding in children after liver transplantation and is associated with a high risk of developing progressive fibrosis, leading to cirrhosis. Standard liver biochemical tests cannot be relied on either in the diagnosis or in the monitoring of progress of chronic allograft hepatitis. In contrast, the presence of autoantibodies is strongly associated with the presence of CH. The cause of chronic hepatitis in transplanted allografts is uncertain but may be immune mediated, representing a hepatitic form of chronic rejection. (Hepatology 2006;43:1109–1117.)
Thermoreversible gelation polymer induces the emergence of hepatic stem cells in the partially injured rat liver
Authors: Nagaya Masaki , Kubota Sunao , Suzuki Noboru , Akashi Katsuya , Mitaka Toshihiro
Published: April 2006

Focal injury of the adult liver causes formation of granulomatous tissue and fibrosis. When thermoreversible gelation polymer (TGP) was applied to such defects of the rat liver, complete recovery of hepatic tissues was observed without granulation. We analyzed the mechanism of the regeneration. TGP is a chemically synthesized biocompatible polymer material whose sol-gel transition is reversible by changing the temperature. Cooled TGP was poured into a penetration lesion of the rat liver. Immunohistochemistry and polymerase chain reaction were carried out using tissues and cultured cells isolated from ductular structures. Immunocytochemical and ultrastructural analyses were also conducted. Seven days after TGP treatment, ductular reactions were observed around the wound and ductules elongated to the injured area. Cells in the structures were alpha-fetoprotein (AFP) positive, albumin+, CK19+, c-Kit+, and Thy1+. Hepatocyte-like cells possessing glycogen appeared around the tips of the ductules from day 9. The defect was completely replaced with hepatocytes by day 28. Cells isolated from the ductules expressed Musashi-1, c-Kit, Thy1, AFP, albumin, transferrin, connexin 43, and CK19. When the cultured cells were covered by TGP, they rapidly proliferated to form colonies, whereas without TGP cells gradually died. Morphologically and ultrastructurally the cells were similar to hepatocytes. They expressed not only albumin and transferrin but TAT, CYP2E1, and CCAAT/enhancer binding protein α. Some cells formed bile canaliculus-like structures.

In conclusion

, TGP may trigger the initiation of hepatic stem cells in biliary ductules, and stem cell activation may occur even in the regeneration of the normal liver. (Hepatology 2006;43:1053–1062.)
Antiproliferative effects of interferon alpha on hepatic progenitor cells in vitro and in vivo
Authors: Lim Rebecca , Knight Belinda , Patel Keyur , McHutchison John G. , Yeoh George C. , Olynyk John K.
Published: April 2006

Hepatic progenitor cells (called oval cells in rodents) proliferate during chronic liver injury. They have been suggested as targets of malignant transformation in chronic liver diseases, including chronic hepatitis C. Interferon alpha therapy reduces the risk of hepatocellular carcinoma (HCC) in chronic hepatitis C regardless of viral clearance. The aim of this study was to determine whether interferon alpha could reduce the risk of HCC by modifying preneoplastic events in the hepatic progenitor cell population. Pre- and post-treatment liver biopsies were evaluated for changes in the hepatic progenitor cell population in 16 patients with non-responding chronic hepatitis C. Interferon alpha–based treatment significantly reduced the numbers of c-kit–positive hepatic progenitor cells by 50%. To determine the mechanism of cell number reduction, the effects of interferon alpha on murine hepatic progenitor cells were studied in vitro. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) proliferation assay and proliferating cell nuclear antigen staining showed that interferon alpha had a dose-dependent, anti-proliferative effect. Interferon alpha stimulated hepatocytic and biliary differentiation of the oval cell lines reflected by increased expression of albumin and cytokeratin19 accompanied by decreased expression of alphafetoprotein and Thy-1. To validate these results

in vivo

, mice were placed on the choline-deficient, ethionine-supplemented diet to induce liver injury and oval cell proliferation and treated with pegylated interferon alpha 2b for 2 weeks. This resulted in a significant four-fold reduction in the number of oval cells (

P

< .05).

In conclusion,

interferon alpha–based treatment reduced the number of hepatic progenitor cells in chronic liver injury by modulating apoptosis, proliferation, and differentiation.

Supplementary material for this article can be found on the HEPATOLOGY website (

http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html

).

(Hepatology 2006;43:1074–1083.)
Elevated serum alanine aminotransferase activity and calculated risk of coronary heart disease in the United States
Authors: Ioannou George N. , Weiss Noel S. , Boyko Edward J. , Mozaffarian Dariush , Lee Sum P.
Published: April 2006

In the United States, elevated serum alanine aminotransferase (ALT) activity in the absence of viral hepatitis or excessive alcohol consumption is most commonly attributed to nonalcoholic fatty liver disease (NAFLD). NAFLD is related to predictors of coronary heart disease (CHD) such as insulin resistance and central obesity. We examined the association between elevated serum ALT activity and the 10-year risk of CHD as estimated using the Framingham risk score (FRS). We performed a cross-sectional analysis comparing participants in the Third National Health and Nutrition Examination Survey with normal and elevated ALT activity (>43 IU/L), examining the mean levels of FRS. Among participants without viral hepatitis or excessive alcohol consumption, those with elevated ALT activity (n = 267) had a higher FRS than those with normal ALT activity (n = 7,259), both among men (mean difference in FRS 0.25, 95% CI 0.07-0.4; hazard ratio for CHD 1.28, 95% CI 1.07-1.5) and women (mean difference in FRS 0.76, 95% CI 0.4-1.1; hazard ratio for CHD 2.14, 95% CI 1.5-3.0). The ALT threshold for increased risk of CHD was higher in men (>43 IU/L) than in women (>30 IU/L). Elevated ALT activity was not associated with higher FRS among nonobese participants with viral hepatitis or excessive alcohol consumption.

In conclusion

, individuals with elevated serum ALT activity in the absence of viral hepatitis or excessive alcohol consumption, most of whom have NAFLD, have an increased calculated risk of CHD. This association is more prominent in women. (Hepatology 2006;43:1145–1151.)
Correlation of initial autoantibody profile and clinical outcome in primary biliary cirrhosis
Authors: Wesierska-Gadek Józefa , Penner Edward , Battezzati Pier Maria , Selmi Carlo , Zuin Massimo , Hitchman Eva , Worman Howard J. , Gershwin Eric M. , Podda Mauro , Invernizzi Pietro
Published: April 2006

Although there have been significant advances in understanding the clinical and biochemical features of primary biliary cirrhosis (PBC), there is still a paucity of data on the usefulness of biomarkers as prognostic indicators. This is particularly important at the time of initial diagnosis. Indeed, the widespread use of antimitochondrial antibody testing has led to an earlier diagnosis of asymptomatic PBC and it is difficult to predict which patients will experience a benign versus a rapidly progressive course. To address this issue, we examined a unique population of 127 newly diagnosed patients with PBC during a 15-year period of observation that began in January 1990. Sera from these patients were analyzed for antimitochondrial, antinuclear, and anti–smooth muscle antibodies, and immunoblotting was performed for nuclear pore complex (NPC). The patients were then followed up longitudinally using biochemical liver function tests. No patient was under any medical therapy for PBC at the time of the initial sera collection. Data were analyzed based not only on the clinical features, but also the Mayo score and specific outcome measures, including time to death, need for liver transplantation, and complication free survival. Among patients with early disease, bilirubin increased to >2 mg/dL in the anti-NPC(+) patients (26% vs. 5%,

P

= .019). Anti-NPC antibodies remained stable or slightly increased over the period of observation.

In conclusion

, anti-NPC identifies patients likely to experience an unfavorable clinical course and more rapid disease progression. (Hepatology 2006;43:1135–1144.)
Hepatitis B virus genotypes, core promoter variants, and precore stop codon variants in patients infected chronically in North‐Eastern Italy
Authors: Dal Molin Gianna , Poli Albino , Crocè Lory S. , D'Agaro Pierlanfranco , Biagi Claudia , Comar Manola , Tiribelli Claudio , Campello Cesare
Published: April 2006

The hepatitis B virus (HBV) genotypes distribution and the core promoter (CP)/precore (PC) variability were evaluated by a line probe assay in 272 patients infected chronically enrolled consecutively in an area of the North‐Eastern Italy. Seven out of the eight genotypes were detected. Italian subjects (83% of the sample) were infected mainly by genotype D (73%) and A (26%); genotype F, and genotype H, were detected only in one subject. In foreigners, the genotype distribution reflected the distribution described for the areas of origin, that is, in Asia genotypes B, C, and D; in Africa genotypes A and E. CP and PC variants prevalence rates were 51% and 60%, respectively, and were significantly higher in Italian patients, probably in relation to their older age. In the analysis restricted to genotypes A and D, PC wild type was linked strongly to genotype A (OR = 4.08, 95% CI = 3.07–5.43, P < 0.0001). In genotype A‐infected patients, only e seroconversion was associated significantly with CP variants. In genotype D‐infected subjects, CP variants were linked significantly to older age and to a higher e seroconversion rate, while PC variants also showed a strong relationship with an ALT lower activity and a lower viral load. In multivariate analysis, HBeAg positivity was associated strongly and independently with younger age, genotype A and CP wild type. Independent determinants of higher viral loads were recognized by increasing age, in male gender and concomitant presence of HBeAg and the CP wild type virus. J. Med. Virol. 78:734–740, 2006. © 2006 Wiley‐Liss, Inc.
Prevalence of antibodies against A and B influenza viruses in South‐Western Papua New Guinea
Authors: Puzelli Simona , Boros Stefano , Affinito Chiara , Calzoletti Laura , Facchini Marzia , Danaya Robert T. , Owen Ifor L. , Pozio Edoardo , Rezza Giovanni , Donatelli Isabella
Published: April 2006

Influenza viruses remain a major cause of respiratory disease in both developed and developing countries. Nevertheless, there is little information on the prevalence of this respiratory infection in many developing countries, such as Papua New Guinea, since most of the available data originate from studies carried out in industrialized countries. In the present study, a serosurvey among residents of 47 remote villages of Papua New Guinea was conducted to evaluate the intensity of exposure to human influenza A and B viruses. The data obtained confirm the co‐circulation of these antigenic variants, reported having circulated in the Southern Hemisphere. Variations in seroprevalence of influenza A and B virus infection were found within the study area. J. Med. Virol. 78:820–824, 2006. © 2006 Wiley‐Liss, Inc.
Patterns of serum type 1 and type 2 immune markers in healthy carriers of HTLV‐I
Authors: Birmann Brenda M. , Mueller Nancy E. , Okayama Akihiko , Hsieh Chung‐Cheng , Tsubouchi Hirohito , Harn Donald , Stuver Sherri O.
Published: April 2006

Type 1 immunity appears to be diminished in healthy Japanese carriers of human T‐lymphotropic virus type I (HTLV‐I), but type 2 status remains undetermined. To further examine the subclinical effect of HTLV‐I on host immunity, we measured serum antibodies to the Epstein–Barr virus (EBV) in 415 healthy Japanese adults to broadly characterize type 1 status. Levels of the type 2 biomarkers total immunoglobulin E (IgE), soluble CD23 (sCD23), and soluble CD30 (sCD30) were assessed in 167, 142, and 135 of these subjects, respectively. We analyzed the association of HTLV‐I with levels of each serum marker using linear and logistic regression. Altered EBV antibody profiles that are consistent with deficient type 1 immunity were more prevalent in HTLV‐I carriers than non‐carriers (odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.5–5.3). Carriers also had 45% lower total IgE levels (P = 0.04) than non‐carriers. In contrast, HTLV‐I infection was not significantly associated with elevated levels of sCD23 or sCD30. These observations are contrary to our expectation of elevated type 2 biomarkers among carriers. We conclude that in this population, healthy carriers of HTLV‐I may have subclinical deficiencies in both type 1 and type 2 immunity, and that type 1 and type 2 immunity are not necessarily reciprocal in persons with subclinical immune dysregulation. J. Med. Virol. 78:847–852, 2006. © 2006 Wiley‐Liss, Inc.
A case of hydatid cyst associated with postpartum maternal death
Authors: Robertson M. , Geerts L. , Gebhardt G. S.
Published: April 2006

A young, apparently healthy woman from a rural area in South Africa presented in the third trimester of pregnancy with a symptomatic abdominal mass between the uterine fundus and liver. The etiology was established to be an echinococcus cyst of the liver and medical treatment was initiated. The fetal outcome was good but the mother died 3 days postpartum due to an unusual but devastating complication of the hydatid cyst. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Deglaciation and Holocene climate change in the western Peruvian Andes
Authors: Weng Chengyu , Bush Mark B. , Curtis Jason H. , Kolata Alan L. , Dillehay Tom D. , Binford Michael W.
Published: April 2006

Pollen, charcoal, magnetic susceptibility, and bulk density data provide the first paleoecological record spanning the last 33,000 years from the western cordillera of the Peruvian Andes. Sparse super-puna vegetation existed before 30,000 cal yr B.P. around Lake Compuerta (3950 m elevation), prior to a sedimentary hiatus that lasted until c. 16,200 cal yr B.P. When sedimentation resumed, a glacial foreland or super-puna flora is represented in which Polylepis was a significant element. Glacial outwash, marked by high sedimentary magnetic susceptibility, increased from c.16,200 cal yr B.P. and reached a peak at c. 13,200 cal yr B.P. Between c. 12,500 cal yr B.P. and 10,000 cal yr B.P., magnetic susceptibility was reduced. Vegetation shifts suggest a cool dry time, consistent with regional descriptions of the Younger Dryas event. Deglaciation resumes by 10,000 cal yr B.P. and the last ice is lost from the catchment at ∼7500 cal yr B.P. During the early Holocene warm and dry period between 10,000 and 5500 cal yr B.P., Alnus expanded in downslope forests. Alnus declined in abundance at 5500 cal yr B.P. when wetter and cooler conditions returned and human activity intensified. Maize (Zea mays) pollen first occurred in the core at ∼2600 cal yr B.P., indicating a minimum age for local agriculture. An increase in Alnus pollen abundance at ∼1000 cal yr B.P. could be due to human activity or perhaps due to a regional climate change associated with cultural turnover elsewhere in the Andes at this time.
Turbulent mean reaction rates in the limit of large activation energies
Authors: Peters N. , Hocks W. , Mohiuddin G.
Published: April 2006

Closed-form expressions for the turbulent mean reaction rate and its covariance with the temperature are derived for premixed and non-premixed combustion. The limit of large activation energies is exploited for a chemical reaction rate that, by virtue of coupling functions, depends on the mixture fraction and a non-equilibrium progress variable only. The probability density function (p.d.f.) formulation with an assumed shape of the p.d.f. is used; a beta-function distribution is assumed for the progress variable. The mean reaction rate is expressed in terms of the mean and the variance of the temperature and, for non-premixed combustion, of the mixture fraction. The reaction kinetics are represented by the non-dimensional activation energy and the laminar flame velocity. For non-premixed systems the possibility of local extinction by flame stretch is considered.
The nonlinear behaviour of a constant vorticity layer at a wall
Authors: Pullin D. I.
Published: April 2006

The so-called ‘water-bag’ method is used to study the behaviour of a two-dimensional inviscid layer of constant vorticity ω and of mean thickness δ adjacent to a wall with slip at the wall. A nonlinear initial-value equation is derived which describes the motion of the material interface separating the rotational fluid within the layer from the irrotational free stream, for the case where this interface is subject to streamwise cyclic disturbances to its undisturbed shape. A linearized solution to this equation shows that a sinusoidal disturbance of wavelength λ propagates as one mode of a neutrally stable Kelvin-Helmholtz wave with velocity ωλ[1 − exp (−4πδ/λ)]/4π relative to the fluid at infinity. Numerical solutions of the full nonlinear equation for a range of wavelengths and finite disturbance amplitudes indicate different behaviour. For sufficiently large amplitude the interface valleys evolve into long re-entrant wedges of irrotational fluid which are ‘entrained’ into the layer and which are separated from the free stream by lobes or bulges of rotational fluid. This single-mode nonlinear interfacial distortion could be generated over a broad wavelength range with no indication of preferential scaling based on δ. It is suggested that the interface behaviour bears distinct resemblance to flow features observed at the interface between turbulent and non-turbulent fluid in recent smoke-in-air flow-visualization studies of the outer part of a constant pressure turbulent boundary layer. The calculated rotational fluid lobe velocities, which are not very different from the equivalent linearized wave velocities, are found to be in reasonable agreement with the few existing measurements of the velocity of bulges at the turbulent–nonturbulent fluid interface, while the computed velocity field in the lobe is in qualitative agreement with the general flow pattern observed in experiments. In the absence of a preferred scale or range of scales for the development of the interfacial distortion, however, it is concluded that the present results cannot be interpreted as supporting the hypothesis of the presence of largescale coherent motions in the outer part of the layer.
Wave-energy extraction by a submerged cylindrical resonant duct
Authors: Simon M. J.
Published: April 2006

A cylindrical duct absorbing energy from incident surface waves is considered. The asymptotic properties of the scattering and radiation potentials are determined, to yield the hydrodynamic quantities on which the energy absorption characteristics of the duct can be shown to depend. It is shown that it is possible to tune the resonant response of the duct to absorb the maximum theoretical energy at a given frequency. Curves are presented showing the variation of energy absorption and the amplitude of the duct response with frequency for various depths of submergence and various tuning frequencies.
On water waves produced by ground motions
Authors: Sabatier Pierre C.
Published: April 2006

A linear and irrotational model is constructed to represent the formation of water waves by ground motions of a sloping bed. A survey of the constant depth case, given first, helps in understanding the mechanism of formation, and, in this oversimplified case, wave propagation away from a source, which is usually very asymmetric. The importance of asymmetry, which may produce trapped waves, is illustrated by an estimate of the propagation in a three-dimensional case. The formation of waves by a ground motion on a slope is then studied in detail. The problem is reduced to linear integral equations of the first kind. Using an inversion technique one constructs a source–response pair in which the source is ‘δ-like’ and the response is close to that which would be found if the depth was constant around the source. A general approximate solution is then derived, in both the two-dimensional and three-dimensional cases. Results for the sloping-bottom case are given for small times. They give initial values of surface displacement. They also enable one to determine the important physical parameters in the ground motion and to evaluate the efficiency of wave production.