bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic analysis of the Mid‐Atlantic Ridge morphology and gravity between 15°N and 40°N: Constraints of the thermal structure
Authors: Thibaud Rémy , Gente Pascal , Maia Márcia
Published: April 2004

Multibeam bathymetry data obtained along a 2400 km long section of the Mid‐Atlantic Ridge (MAR) from 15°N to the Azores platform (40°N) and satellite‐derived gravity data were used to calculate the mantle Bouguer anomaly (MBA) along this portion of the MAR. Both data sets were used to determine the relations between gravity anomalies and topographic variations and discuss these in terms of thermal difference. A long‐wavelength influence of the Azores hot spot is characterized by a gentle, continuous slope of the average ridge axial depth and a general gradient in the along‐axis MBA profile. This thermal influence of the Azores hot spot controls a systematic southward propagation of the spreading segments at least to 26°30′N. South of 26°30′N, the direction of the segment propagation is controlled by the local difference in thermal state between adjacent segments. Except on the Azores platform, the systematic along‐axis 11–90 km long wavelength segmentation is independent of the long‐wavelength influence of the Azores. At the segment center, the axial morphology is linked to the thermal state of the segments between: (1) “Hotter segments” characterized by a smooth axial morphology, a well‐defined shallow ”inner valley”, high ΔMBA and a long length;(2) “colder segments” which present a rough axial morphology with a deep, wide and well‐defined rift valley, a low ΔMBA and a small length. For ”hotter segments” the formation of the abyssal hills is mainly due to a magmato‐tectonic cycle over periods of 0.3 to 1 Myr, whereas on “colder segments” the axial morphology is mainly controlled by a tectonic rift valley formation. We propose that these different segment types correspond to a temporal evolution of the rift valley morphology over periods of several million years.
Compressive failure of rocks by shear faulting
Authors: Gupta V. , Bergström J. S.
Published: April 2004

A model for the compressive failure of rocks via the process of shear faulting is presented. The model addresses the progressive growth of damage that leads to the formation of a critical fault nucleus which grows unstably in its own plane by fracturing the grain boundaries in an increasingly rapid succession. The model uses a two‐parameter Weibull‐type shear strength distribution for defining the nucleation of initial damage, followed by the use of stress enhancement factors for addressing the increased probability of failure in the vicinity of already cracked grain boundaries. These factors essentially involve surface averaging of enhanced stresses in the neighboring grains with the appropriate strength distribution as the weighting function. As the stress is further increased, similar correlated fracturing events get preferentially aligned to the crack cluster, resulting in en echelon of cracks. This crack cluster is modeled as an elliptical inhomogeneity within which the cracks interact and lead to material pulverization, the effect of which, mechanistically, is to lower the shear modulus compared with the uncracked material on the outside. The shear stress concentration resulting from this moduli mismatch is calculated and used to compute the stress enhancement factors for defining the nucleation of additional cracking events near the crack cluster. Eventually, the size of the crack cluster becomes sufficiently large that it carries a stress concentration high enough to fracture all grain boundary elements in from of it in an increasingly rapid succession. The stress associated with this event is taken as the failure stress. Since the model allows other cracking events to occur within the material volume in accordance with the assumed strength distribution function, formation of other competing but subcritical shear faults naturally occurs. Besides the faulting stress for a prescribed confinement, the model is able to predict the angle of the shear fault fairly well. The model is applied to a variety of rock types, including granite, eclogite, gabbro, aplite, rock salt, sandstone, dunite, limestone, and marble, and the predicted failure envelopes compare rather well with the failure data available in the literature.
Interpretation of domainal groundmass textures in basalt lavas of the southern Lamington Volcanics, eastern Australia
Authors: Smith John V.
Published: April 2004

The arrangement of crystals, vesicles, and glass in the matrix of a volcanic rock records information about the kinematics accompanying its formation. Simple rock textures involve homogeneous distributions of features such as aligned crystals, whereas more complex rock textures involve inhomogeneous distributions comprising subregions or domains of homogeneous textural types. In the groundmass of volcanic rocks, two types of domainal textures are defined by (1) differences in the degree of alignment or direction of alignment of crystals and (2) different concentrations of crystals. A petrographic survey of basalt lavas of the Tertiary Lamington Volcanics in northeast New South Wales, Australia, reveals the presence of both crystal alignment and crystal concentration domainal textures. Alignment domains are interpreted as shear zones overprinting homogenous aligned textures during flow. The formation of crystal concentration domains appears to involve multiple processes including (1) crystal clustering during flow, (2) complex overprinting of dilatant groundmass shear zones, (3) melt segregations due to stress, or (4) postvesiculation processes.
Formation of lava tubes and extensive flow field during the 1991–1993 eruption of Mount Etna
Authors: Calvari Sonia , Pinkerton Harry
Published: April 2004

Detailed mapping during the 1991–1993 eruption of Mount Etna has shown that there is a relationship between tumuli, ephemeral vents, lava tubes, and their parent lava flows. During this eruption, many tubes formed in stationary, inflated ‘a‘a lava flows. Ephemeral vents at the fronts of these stationary flows and above lava tubes fed secondary lava flows, many of which subsequently developed new tubes. The resulting complex network of tubes, ephemeral vents, and secondary flows was responsible for most of the widening, thickening, and lengthening of the 1991–1993 Etna lava flow field. The supply of relatively uncooled lava via tubes to distal parts of this flow field allowed lava to flow 3 km farther from the vent than the longest channel‐fed lava flow. Our observations suggest that lava tubes play a more important role in the formation of extensive ‘a‘a flow fields on Etna than has previously been recognized.
Observations on basaltic lava streams in tubes from Kilauea Volcano, island of Hawai'i
Authors: Kauahikaua Jim , Cashman Katharine V. , Mattox Tari N. , Heliker C. Christina , Hon Ken A. , Mangan Margaret T. , Thornber Carl R.
Published: April 2004

From 1986 to 1997, the Pu'u 'O'o‐Kupaianaha eruption of Kilauea produced a vast pahoehoe flow field fed by lava tubes that extended 10–12 km from vents on the volcano's east rift zone to the ocean. Within a kilometer of the vent, tubes were as much as 20 m high and 10–25 m wide. On steep slopes (4–10°) a little farther away from the vent, some tubes formed by roofing over of lava channels. Lava streams were typically 1–2 m deep flowing within a tube that here was typically 5 m high and 3 m wide. On the coastal plain (<1°), tubes within inflated sheet flows were completely filled, typically 1–2 m high, and several tens of meters wide. Tubes develop as a flow's crust grows on the top, bottom, and sides of the tubes, restricting the size of the fluid core. The tubes start out with nearly elliptical cross‐sectional shapes, many times wider than high. Broad, flat sheet flows evolve into elongate tumuli with an axial crack as the flanks of the original flow were progressively buried by breakouts. Temperature measurements and the presence of stalactites in active tubes confirmed that the tube walls were above the solidus and subject to melting. Sometimes, the tubes began downcutting. Progressive downcutting was frequently observed through skylights; a rate of 10 cm/d was measured at one skylight for nearly 2 months.
Origin of north Queensland Cenozoic volcanism: Relationships to long lava flow basaltic fields, Australia
Authors: Sutherland F. L.
Published: April 2004

A plume model proposed for north Queensland late Cenozoic volcanism and long lava flow distribution combines basalt ages with recent seismic studies of Australia's mantle, regional stress fields, and plate motion. Several basalt fields overlie mantle “thermal” anomalies, and other fields outside these anomalies can be traced to them through past lithospheric motion. Elsewhere, anomalies close to Australia's eastern rift margin show little volcanism, probably due to gravity‐enhanced compression. Since final collision of north Queensland with New Guinea, areas of basaltic volcanism have developed over 10 Myr, and episodes appear to migrate southward from 15° to 20°S. Long lava flows increase southward as area/volume of fields increases, but topography, vent distributions, and uplifts play a role. This is attributed to magmatic plume activation within a tensional zone, as lithosphere moves over mantle thermal anomalies. The plume model predicts peak magmatism under the McBride field, coincident with the Undara long lava flow and that long lava flow fields will erupt for another 5–10 Myr. Queensland's movement over a major N‐S thermal system imparts a consistent isotopic signature to its northern younger basalts, distinct to basalts from older or more southern thermal systems. Australia's motion toward this northern thermal system will give north Queensland fields continued vigorous volcanism, in contrast to the Victorian field which is leaving its southern thermal system.
Aircraft to aircraft intercomparison during SEMAPHORE
Authors: Lambert Dominique , Durand Pierre
Published: April 2004

During the Structure des Echanges Mer‐Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale (SEMAPHORE) experiment, performed in the Azores region in 1993, two French research aircraft were simultaneously used for in situ measurements in the atmospheric boundary layer. We present the results obtained from one intercomparison flight between the two aircraft. The mean parameters generally agree well, although the temperature has to be slightly shifted in order to be in agreement for the two aircraft. A detailed comparison of the turbulence parameters revealed no bias. The agreement is good for variances and is satisfactory for fluxes and skewness. A thorough study of the errors involved in flux computation revealed that the greatest accuracy is obtained for latent heat flux. Errors in sensible heat flux are considerably greater, and the worst results are obtained for momentum flux. The latter parameter, however, is more accurate than expected from previous parameterizations.
Radiative characteristics of regional hazes dominated by smoke from biomass burning in Brazil: Closure tests and direct radiative forcing
Authors: Ross John L. , Hobbs Peter V. , Holben Brent
Published: April 2004

Ground‐based Sun photometer measurements, and airborne measurements of the physical and optical properties of regional hazes dominated by smoke from biomass burning in Brazil, are used for aerosol radiative vertical column and local radiative closure tests. Optical depths at midvisible wavelengths of up to 2.5 measured by two independent methods (ground‐based Sun photometers and airborne measurements of the vertical profiles of aerosol optical extinction to the top of the smoke layer) agreed, on average, to within ∼20%. Local aerosol closure tests were carried out using in situ measurements of particle size distributions as inputs to a computational model of the aerosol. Calculated aerosol masses, aerosol absorption and scattering coefficients, and the amounts of solar radiation backscattered by the aerosol were generally within 25% of the measured values. The computational model was used to calculate a broader range of radiative transfer parameters, including aerosol mass scattering and absorption efficiencies, the asymmetry parameter, and upscatter fraction, across the solar spectrum. Regional values of direct aerosol radiative forcing produced by smoke aerosol in the cerrado and primary forest areas of Brazil are derived using the radiative transfer parameters as inputs to a radiative transfer model. The resulting net direct radiative forcing can result in either a cooling or a heating depending on the underlying surface albedo. Over a typical tropical forest the change in the daily average net shortwave flux per unit optical depth (at a wavelength of 550 nm) is −20 ± 7 W m−2 (where a negative value indicates cooling). Over the cerrado the forcing is −8± 9 W m−2, while over a dark surface, such as the ocean, the forcing is −26±6 W m−2. Over a reflective surface, such as a desert, we calculate a positive (heating) forcing of +25±12 W m−2.
How to enter the pediatric airway for bronchoscopy
Authors: Niggemann Bodo , Haack Marion , Machotta Andreas
Published: April 2004

Abstract
Background
: Bronchoscopies are performed in childhood for diagnostic reasons (e.g. evaluation of stridor, unexplained cough, possible malformations) and therapeutic reasons (e.g. foreign body removal, management of the difficult airway).

Methods
: Various procedures of entering the pediatric airways are presented, based on an overview of the literature and the experience of the authors.

Results
: The advantages and disadvantages of direct fibreoptic bronchoscopy, bronchoscopy via face mask, via laryngeal mask airway, via tracheal tube, and for combined flexible and rigid bronchoscopy are discussed. In addition, practical aspects of bronchoscopy are considered, including local anesthesia, oxygen supplementation, monitoring, antibiotic treatment.

Conclusions
: Although inspection of the pediatric airways has become a well‐accepted routine procedure with a high diagnostic yield, and bronchoscopies are well tolerated, it is important that the most appropriate means of access to the airways is chosen according to the indications and the age of the child.
Screening for developmental dysplasia of the hip: Results of a 7‐year follow‐up study
Authors: Şahİn Fİgen , Aktürk Aysİma , Beyazova Ufuk , ÇakIr Banu , BoyunaĞa Öznur , Tezcan Sabahat , BölükbaŞI Selçuk , KanatlI Ulunay
Published: April 2004

Abstract
Background
: Screening for developmental dysplasia of the hip (DDH) is widely recommended for all infants to prevent disability from late diagnosis of dislocation of the hip. The present study evaluates the results of screening for developmental dislocation of hip in a clinic in Turkey over the course of 7 years.

Methods
: Hospital records of 5798 infants who were examined regularly until walking age at Gazi University well child clinics between January 1995 and December 2001 were reviewed. Infants with known risk factors for DDH such as breech presentation, family history of DDH or swaddling, and of infants with physical examination findings suggestive of DDH, were referred to orthopedic surgeons for diagnosis. Based on this final diagnosis, sensitivity, specificity, positive and negative predictive values of risk factors and physical examination findings were calculated.

Results
: Of the 5798 infants, risk factors were detected in the medical history of 111 infants, and in 14 infants a musculoskeletal deformity was detected. In 606 infants the physical examination findings were suggestive of DDH. Ten patients were subsequently diagnosed with DDH. The sensitivity, specificity, positive predictive value and negative predictive values of having a risk factor for DDH in history were 10.0%, 98.1%, 0.9%, 99.8%, and having abnormal hip examination findings were 100.0%, 88.9%, 1.6% and 100.0%, respectively.

Conclusion
: A careful history and physical examination is the cornerstone of DDH screening. Serial hip examinations performed during health examination visits provide an opportunity to identify DDH cases. The sensitivity of risk factors in history and physical examination findings together is high enough to be accepted as a screening tool.
Enteroviral hepatitis in children
Authors: Kawashima Hisashi , Ryou Shimizu , Nishimata Shigeo , Ioi Hiroaki , Kashiwagi Yasuyo , Iizumi Mamoru , Takami Takeshi , Sasamoto Masato , Takekuma Kouji , Hoshika Akinori , Mori Takayuki
Published: April 2004

Abstract
Background
: The pathogen causing enteroviral hepatitis is often not found despite careful examination.

Methods
: This study investigates the enterovirus genome in serum and liver tissue obtained from patients who showed abnormal liver function without negative data of usual studies and cytomegalovirus (CMV) serologically positive cases.’

Results
: Nine out of 21 serum samples were positive by using reverse transcriptase‐polymerase chain reaction (RT‐PCR) for enterovirus. The 21 samples had CMV‐IgM antibodies in five cases. These CMV serologically positive cases were all negative for enterovirus using RT‐PCR. Therefore, nine out of 16 (60%) were of unknown etiology. Some cases showed liver dysfunction over a period of more than 6 months. The liver function revealed that all cases finally improved. The sequences coincided with those of Coxsackie B5 or B6 with the highest score by gene homology search. The liver pathology revealed that two of three subjected cases had mild fibrosis and small cell infiltration. RT‐PCR of liver tissue for enterovirus were positive in all three cases comparing the house keeping gene. The viral load was high in acute phase and low in convalescent phase.

Conclusion
: In more than half of children with illnesses of unknown etiology, the pathogen was found to be enteroviruses, and RT‐PCR and quantification of serum is an easy method to identify these diseases.
Spontaneous closure of ventricular septal defects followed up from <3 months of age
Authors: Miyake Toshiharu , Shinohara Tohru , Nakamura Yoshihide , Fukuda Tsuyoshi , Tasato Hiroshi , Toyohara Keiko , Tanihira Yuko
Published: April 2004

Abstract
Background
: This study evaluates the incidence and timing of spontaneous closure (SC) of ventricular septal defect (VSD) using Doppler color flow mapping.

Methods
: A total of 225 infants (mean age 30 days) were diagnosed with uncomplicated VSD: 31 (14%) subpulmonary VSD, 159 (70%) perimembranous, and 35 (16%) muscular. The patients were divided into two groups according to the presence or absence of congestive heart failure (CHF). SC was confirmed with color Doppler.

Results
: Surgical closure was performed in 59 patients (26%). SC occurred in 107 patients (48%); three (10%) of 31 with subpulmonary VSD, 75 (47%) of 159 with perimembranous VSD, and 29 (83%) of 35 with a muscular VSD. Average age at SC was 19 months. In three SC patients with a subpulmonary VSD, there was no aortic valve prolapse and no aortic regurgitation. SC occurred in 96% of SC patients with a perimembranous VSD by the age of 6 years, and in 93% of those with a muscular VSD by the age of 3 years. In patients without CHF, the rate of SC was 72%; 23% in subpulmonary VSD, 74% in perimembranous, and 85% in muscular. SC occurred in only 23% of patients with a perimembranous VSD with CHF. Mean age at the final examination was 6.9 years in 59 patients with a VSD remaining open, and 63% of patients with a perimembranous VSD remaining open had an aneurysm of the ventricular membranous septum.

Conclusions
: The SC rate of VSD by mean age of 6.9 years was 48%, but it was 72% in patients without CHF. In patients with CHF, SC was seen only in patients with a perimembranous VSD. The rate of SC was 10% in subpulmonary VSD. The authors contend that SC probably occurred by growth of muscular septum surrounding VSD. Muscular VSD spontaneously closed earlier than perimembranous VSD.
Rare clinical presentation mode of intestinal malrotation after neonatal period: Malabsorption‐like symptoms due to chronic midgut volvulus
Authors: İmamoĞlu Mustafa , Çay Ali , Sarihan Haluk , Şen YaŞar
Published: April 2004

Abstract
Background
: Many different and non‐specific clinic presentation modes of malrotation anomalies (MA) have been reported after neonatal period. The authors describe four children with MA presented with malabsorption‐like clinical features.

Methods
: Three children aged from 8 months to 7 years, with a history of long‐standing diarrhea and failure to thrive attributed to malabsorption, were referred to Department of Pediatric Surgery, for evaluation of suspected MA. Another patient, a 10‐year‐old boy who was treated for malabsorption for 6 years, presented with acute duodenal obstruction findings. The duration of symptoms averaged 35 months, ranging 8 months to 6 years. All patients had undergone extensive evaluation and empiric trials of different formulas with no improvement in their symptoms. One underwent jejunal biopsy.

Results
: Primary presentation complaints were chronic diarrhea and failure to thrive in three patients. Their histories revealed chronic (in one) and intermittent colicky (in two) abdominal pain, and intermittent nonbilious vomiting (in three). The remaining patient presented with acute illness, with chronic diarrhea, failure to thrive, and intermittent abdominal pain and vomiting on his history. They were below 30th percentile according to body weight and height. Laboratory studies revealed hypoproteinemia, hypoalbunemia, raised liver function tests, and anemia in all patients. The patient who presented acutely had double‐bubble sign on the plain abdominal film obtained at admission. In the other three, plain films obtained during an attack of abdominal pain and/or vomiting revealed findings of partial intestinal obstruction. The diagnosis was confirmed by upper gastrointestinal series. At their laparotomy, a classical type of malrotation with circumstantial evidence of chronic volvulus was noted. All patients had normal laboratory values between postoperative 3 and 5 weeks, and they were up to 30th percentile at the end of the 6 months.

Conclusion
: Malrotation anomalies should be included in the differential diagnosis in a child presented with malabsorption‐like clinical features.
Role of serum neutralizing antibody in reinfection of respiratory syncytial virus
Authors: Kawasaki Yukihiko , Hosoya Mitsuaki , Katayose Masahiko , Suzuki Hitoshi
Published: April 2004

Abstract
Background
: To clarify the role of serum antibody in respiratory syncytial virus (RSV) reinfection, the authors conducted a follow‐up study of patients with primary RSV infection.

Methods
: From 1994 to 1995, 256 patients were a diagnosed with primary RSV infection based on the antigen detection in nasopharyngeal secretions using enzyme linked immunoassay method. One hundred and sixty‐five patients were followed‐up for 1 year, and 87 of the 165 patients showed respiratory symptoms in winter. When a patient had a symptom such as cough, wheezing, rhinorrhea or fever, the nasopharyngial secretion was examined for the presence of RSV. Forty‐one patients (group 1) were diagnosed with reinfection with RSV and the other 46 patients (group 2) were not diagnosed with reinfection. The authors compared clinical features between primary infection and reinfection of group 1 and serum neutralization test (NT) antibody titers to RSV between group 1 and 2.

Results
: The mean age was 6.0 ± 3.6 months at RSV primary infection and 14.6 ± 8.2 months at RSV reinfection. Hospitalization, oxygen supplementation, and use of respirator were required by 71%, 39%, 2%, respectively, in primary infection, and by 22%, 0%, 0%, respectively, in reinfection. All children in group 1 had titers of 1 : 16 or lower, while 39.1% of children in group 2 had titers of 1 : 16 or lower (P < 0.05). No patient with the titers of 1 : 32 or higher had symptomatic reinfection. Serum NT antibodies to RSV of outpatients were higher than those of inpatients at reinfection.

Conclusions
: The severity of illness in RSV reinfection is generally milder than that in primary infection. Our findings suggest that NT antibodies play an important role in reducing the severity of illness as well as in protection from RSV reinfection.
Molecular epidemiology of measles virus in Japan
Authors: Nakayama Tetsuo , Fujino Motoko , Yoshida Naoko
Published: April 2004

Abstract
Background
: Measles virus has been classified into 22 genotypes. The present report examines the molecular epidemiology of measles virus in Japan from 1984 to 2002, and the epidemiological link between imported cases in several foreign countries and Japanese strains was elucidated from the literature.

Methods
: B95a or Vero cells was used to isolate the measles virus. The measles virus genome was amplified in the N and H genes by reverse transcriptase‐polymerase chain reaction and were partially sequenced. Phylogenetic analysis of a partial sequence of the N gene, from position 1230 to 1685, of the recent measles strains was performed in comparison with the World Health Organization reference strains.

Results
: There were large outbreaks of measles in Japan in 1984, 1987−1988, 1991−1993, and 2001−2002 and each outbreak was caused by a different genotype. Genotype C1 was an indigenous strain for a long period before 1985, while D3 was isolated in 1987−1988 and D5 in 1991−1993 outbreaks. In addition, the Chicago‐type D3 caused sporadic regional outbreaks from 1998 to 1999. After 2000, H1 became the dominant circulating strain. It should be noted that the Japanese strains were detected as imported cases by epidemiological linkage in several countries.

Conclusion
: Among the recent circulating strain of measles virus in Japan the genotype H1 was dominant after 2000 and the Japanese strains D3, D5, and H1 were exported to several countries. It is recommended that Japan should adopt a more extensive and active vaccination strategy for measles elimination in line with other countries in the world.
Molecular epidemiology of rubella virus in Asia: Utility for reduction in the burden of diseases due to congenital rubella syndrome
Authors: Katow Shigetaka
Published: April 2004

Abstract
Background
: Rubella is a mild disease mainly of infants, involving a rash and a fever. However, when women who have no immunity to rubella are infected during the early stage of pregnancy, their babies are often born with congenital rubella syndrome (CRS), which is characterized by a few disorders including deafness, cataracts and heart malformations. To prevent CRS, several strains of live attenuated rubella vaccine have been developed and introduced into immunization programs in many countries. In most Asian countries except Japan, Singapore and Taiwan, rubella remains uncontrolled, and the burden of diseases from CRS is high. In order to develop a control program to reduce the number of CRS cases in Asian countries, it is necessary to conduct a survey of rubella and CRS cases, and to then determine the genotype of the circulating rubella virus in each country.

Methods
: Cases of rubella and CRS, based on national reporting systems or active surveillance in the Asian countries, are summarized. Sequences of the E1 gene of the virus isolates from the Asian countries were compared by phylogenic analysis.

Results
: Recent studies of the molecular epidemiology of rubella virus worldwide revealed that there are two genotypes, and that genotype I is circulating almost worldwide, while genotype II is an Asian prototype restricted to the Asian continent. Genotype I viruses fall into a number of groups, some of which are geographically localized. Antigenically these two genotypes are cross‐reactive and immunization with either virus results in immunity to all rubella viruses.

Discussion
: The hypotheses that rubella virus has evolved on the Asian continent is proposed. The World Health Organization (WHO) has recognized that a rubella immunization program can be combined with the measles immuization program. Inclusion of rubella in the expanded program of immunization (EPI) of measles would be ideal in Asian countries, as it would be efficient and cost effective to administer one injection containing a three‐combined vaccine (MMR). It would also be desirable given that WHO require laboratory tests to confirm the presence of measles or rubella as part of it's measles control project, because rubella is often misdiagnosed as measles.
Molecular epidemiology of hepatitis B and C virus infections in Asia
Authors: Huy Tran T T , Abe Kenji
Published: April 2004

Abstract The present paper provides a review of the current literature regarding the molecular‐based epidemiology of hepatitis B virus (HBV) and hepatitis C virus (HCV), which are very important viruses underlying the etiology of blood‐borne infectious diseases worldwide. Particularly, both HBV and HCV are widespread on the Asian continent and are associated with acute and chronic liver diseases, including hepatocellular carcinoma. HBV has been classified into genotypes A through G and shown to have a distinct geographic distribution. In Asia, genotypes B and C of HBV prevail, and genotype C has been shown to cause more serious liver disease than genotype B. High prevalence of HBV mutants with various forms, such as the pre‐S mutant, basal core promoter mutant, YMDD motif mutant and vaccine escape mutant, were seen in Asia and these were found to be related to the severity of liver disease and sensitivity to therapy. HCV has also been classified into multiple genotypes and associated with geographic distribution. HCV genotype 1 is less sensitive to interferon therapy and may be associated with the presence of more serious liver disease than the other genotypes. Data on the relation among the HBV/HCV genotypes, their pathogenicity in chronic liver diseases including hepatocellular carcinoma and their effect on therapy are awaited with great interest, especially in Asia, which is an endemic region of blood‐borne hepatitis viruses.
Periventricular low intensities on fluid attenuated inversion recovery imaging in the newborn infant: Relationships to chronic white matter lesions
Authors: Iwata Osuke , Iwata Sachiko , Tamura Masanori , Nakamura Tomohiko , Hirabayashi Shinnichi , Fueki Noboru , Kondou Yoshiaki , Kihara Hideki
Published: April 2004

Abstract
Background
: Neurological disadvantages due to hypoxic ischemic encephalopathy (HIE) are still very serious problems. In order to support the infant with HIE, it is important to evaluate the severity of the brain injury early. The authors performed a magnetic resonance imaging (MRI) study of the neonatal brain in order to assess the clinical value of periventricular low intensities (PVLI) detected on fluid attenuated inversion recovery (FLAIR) imaging.

Methods
: A total of 451 MRI from 167 preterm and 113 term infants were sorted into groups according to the corrected age at the time of scanning. Intensities in the white matter were then divided into five grades according to the severity of the finding on FLAIR imaging. Chronic abnormalities such as periventricular hyperintensities (PVHI) were also analyzed.

Result
: In early MRI, which was obtained before 2 months corrected age, the incidence of PVLI was 63%, while it was only 3% and 0% in the middle (2−8 months) and the late (8−18 months) scans, respectively. Instead of PVLI, PVHI were commonly observed both on late FLAIR imaging (89%) and late T2‐weighted imaging (72%). The severity of the white matter damage diagnosed on early FLAIR imaging had a significant correlation with that of late FLAIR imaging.

Conclusion
: F‐PVLI on early FLAIR imaging would be a good predictor of chronic white matter damage. FLAIR imaging would be also useful in follow‐up of infants because of its high sensitivity to the chronic white matter lesion.
Biliary atresia in Turkish children
Authors: AydoĞdu Sema , Özgenç Funda , Atİk Tahir , Ünal Fatih , Tokat Yaman , Yagci Rasit Vural
Published: April 2004

Abstract
Aim
: To evaluate surgical success, survival rate and relationship of outcome parameters with time at diagnosis and operation of extrahepatic biliary atresia (EHBA) patients in İzmir, Turkey.

Methods
: Clinical and laboratory data were reviewed from case reports of 27 EHBA patients. Twenty‐five patients were operated on using Kasai procedure and two cases received liver transplants without portoenterostomy due to decompansated liver cirrhosis on diagnosis. Post operational success was defined as clearance of jaundice (bilirubine level <2 mg/dL). Patients were studied in two groups: I (jaundice free and/or compensated liver disease with liver transplant if needed after 3 years of age) and II (progressive liver disease with death or liver transplant if needed before 3 years of age). Kasai success, age at diagnosis and operation, survival and correlation of outcome with age, preoperative liver functions were evaluated. Eight patients received liver transplants.

Results
: Median age at diagnosis was 63.5 days (21−212) and portoenterostomy was performed at median age of 67.5 days (25−220). Kasai operation was successful in two cases (8%) and the operation was performed at 35 and 42 days. Age at diagnosis (P = 0.13) and operation (P = 0.2) was not different between the two groups. Group I and II consisted of seven (28%) and 18 (72%) infants. Pre‐existing ascites, serum alanine aminotransferase (ALT) and globulin levels were significantly higher in group II patients (P = 0.008, P = 0.04, P = 0.017, respectively).

Conclusion
: The results of the present study indicate that general practitioners should pay close attention to the evaluation of infants with prolonged jaundice in Turkey. Because of frequent late diagnosis presenting with cirrhosis at admission and also because of the low organ donation rates in Turkey, living related liver transplantation is an option and is currently undergoing detailed ethical consideration.
Molecular epidemiology of viral gastroenteritis in Asia
Authors: Okitsu‐Negishi Shoko , Nguyen Tuan Anh , Phan Tung Gia , Ushijima Hiroshi
Published: April 2004

Abstract Acute gastroenteritis is one of the most common diseases in humans, and continues to be a significant cause of mortality and morbidity worldwide. Recently the estimates of mortality associated with diarrhea declined, however the majority of deaths still occur in developing countries and thus urgent intervention is needed for the prevention of these diseases. In Asian countries it is very important to study the distribution, transmission and characteristics of prevalent viruses in order to produce viral vaccines. The viruses which cause gastroenteritis are primarily from four distinct families − group A rotaviruses, caliciviruses, enteric adenoviruses and astroviruses. Rotavirus is a common virus that causes severe gastroenteritis in children <5 years of age. The reassortant viruses with animal virus, or directly animal viruses are isolated in humans. The future development of a safe and effective vaccine against rotavirus, along with the expansion of understanding of the distribution of types in Asia and an availability of rapid diagnostic tests, could reduce mortality and might be able to prevent severe gastroenteritis. Calicivirus is a causative virus of acute gastroenteritis in children and has been known to contaminate food causing viral outbreaks affecting people of all ages. Recently, the understanding of calicivirus and the improvement of detection techniques has increased the total frequencies of diarrheal viruses. For the future control and prevention of diarrheal diseases it is necessary to examine the molecular epidemiology of caliciviruses as well as rotaviruses.
Bayesian Networks for Imputation
Authors: Di Zio Marco , Scanu Mauro , Coppola Lucia , Luzi Orietta , Ponti Alessandra
Published: April 2004

Bayesian networks are particularly useful for dealing with high dimensional statistical problems. They allow a reduction in the complexity of the phenomenon under study by representing joint relationships between a set of variables through conditional relationships between subsets of these variables. Following Thibaudeau and Winkler we use Bayesian networks for imputing missing values. This method is introduced to deal with the problem of the consistency of imputed values: preservation of statistical relationships between variables (statistical consistency) and preservation of logical constraints in data (logical consistency). We perform some experiments on a subset of anonymous individual records from the 1991 UK population census.
Multiscale analysis of nonequilibrium rarefied gas flows with the application to silicon thin film process employing supersonic jet
Authors: Sakiyama Y. , Takagi S. , Matsumoto Y.
Published: April 2004

The new method for the analysis of rarefied gas flows is introduced in this paper. This method is based on the multiscale analysis that connects the thermofluid phenomena as different time and spatial scales by constructing the reasonable physical models among them. First, an intermolecular potential model is constructed from the ab initio molecular orbital calculations. Next, the collision models such as the collision cross section and the scattering angle are constructed by the statistical analysis of the classical trajectory calculations with the new intermolecular potential model. Finally, these collision models are applied with the direct simulation Monte Carlo calculation. In this way, this multiscale modeling does not require any empirical parameters except the electron wave functions and this method is widely applicable to the various rarefied gas flows. As a practical example, the interaction of SiH4 and H2 gas, which is widely used in the semiconductor manufacturing process, is considered.
Transactivation of Sphingosine-1–Phosphate Receptors by FcεRI Triggering Is Required for Normal Mast Cell Degranulation and Chemotaxis
Authors: Jolly Puneet S. , Bektas Meryem , Olivera Ana , Gonzalez-Espinosa Claudia , Proia Richard L. , Rivera Juan , Milstien Sheldon , Spiegel Sarah
Published: April 2004

Mast cells secrete various substances that initiate and perpetuate allergic responses. Cross-linking of the high-affinity receptor for IgE (FcεRI) in RBL-2H3 and bone marrow–derived mast cells activates sphingosine kinase (SphK), which leads to generation and secretion of the potent sphingolipid mediator, sphingosine-1–phosphate (S1P). In turn, S1P activates its receptors S1P1 and S1P2 that are present in mast cells. Moreover, inhibition of SphK blocks FcεRI-mediated internalization of these receptors and markedly reduces degranulation and chemotaxis. Although transactivation of S1P1 and Gi signaling are important for cytoskeletal rearrangements and migration of mast cells toward antigen, they are dispensable for FcεRI-triggered degranulation. However, S1P2, whose expression is up-regulated by FcεRI cross-linking, was required for degranulation and inhibited migration toward antigen. Together, our results suggest that activation of SphKs and consequently S1PRs by FcεRI triggering plays a crucial role in mast cell functions and might be involved in the movement of mast cells to sites of inflammation.
Minor H Antigen HA-1–specific Regulator and Effector CD8+ T Cells, and HA-1 Microchimerism, in Allograft Tolerance
Authors: Cai Junchao , Lee Junglim , Jankowska-Gan Ewa , Derks Richard , Pool Jos , Mutis Tuna , Goulmy Els , Burlingham William J.
Published: April 2004

The role of the hematopoietic lineage-restricted minor histocompatibility (H) antigen HA-1 in renal allograft tolerance was explored. We obtained peripheral blood samples from three recipients of histocompatibility leukocyte antigen (HLA)–matched, HA-1–mismatched renal transplants, one of which had discontinued immunosuppression >30 yr ago while sustaining normal kidney function. Peripheral blood mononuclear cells (PBMCs) were injected into the footpads of severe combined immunodeficiency mice to measure human delayed type hypersensitivity (DTH) responses. All three patients manifested regulated DTH responses to HA-1H peptide. By differential tetramer staining intensities, we observed two distinct minor H antigen HA-1–specific CD8+ T cell subsets. The one that stained dimly had the characteristics of a T regulatory (TR) cell and produced interleukin (IL) 10 and/or transforming growth factor (TGF) β. These HA-1–specific TR cells coexisted with bright tetramer-binding CD8+ T effector (TE) cells. The CD8+ TE cells mediated HA-1–specific DTH and produced interferon-γ. Suppression of these TE functions by TR cells was TGFβ, IL-10, and cytotoxic T lymphocyte–associated antigen 4 dependent. In addition, HA-1 microchimerism was detected in two recipients, primarily in the dendritic cell fraction of the PBMCs. This is the first demonstration of coexisting CD8+ memory TR and TE cells, both specific for the same HA-1 antigen, in the context of renal allograft tolerance.
Regenerative Response in Ischemic Brain Restricted by p21cip1/waf1
Authors: Qiu Jianhua , Takagi Yasushi , Harada Jun , Rodrigues Neil , Moskowitz Michael A. , Scadden David T. , Cheng Tao
Published: April 2004

Neural precursor cells from adults have exceptional proliferative and differentiative capability in vitro yet respond minimally to in vivo brain injury due to constraining mechanisms that are poorly defined. We assessed whether cell cycle inhibitors that restrict stem cell populations in other tissues may participate in limiting neural stem cell reactivity in vivo. The cyclin-dependent kinase inhibitor, p21cip1/waf1 (p21), maintains hematopoietic stem cell quiescence, and we evaluated its role in the regenerative response of neural tissue after ischemic injury using the mice deficient in p21. Although steady-state conditions revealed no increase in primitive cell proliferation in p21-null mice, a significantly larger fraction of quiescent neural precursors was activated in the hippocampus and subventricular zone after brain ischemia. The hippocampal precursors migrated and differentiated into a higher number of neurons after injury. Therefore, p21 is an intrinsic suppressor to neural regeneration after brain injury and may serve as a common molecular regulator restricting proliferation among stem cell pools from distinct tissue types.
The Modulation of CD40 Ligand Signaling by Transmembrane CD28 Splice Variant in Human T Cells
Authors: Mikolajczak Sebastian A. , Ma Bruce Y. , Yoshida Tetsuya , Yoshida Ryoko , Kelvin David J. , Ochi Atsuo
Published: April 2004

The role of CD40 ligand (CD40L)/CD40 signaling in T cell–dependent B cell differentiation and maturation has been amply documented. The mechanism of CD40 signaling in B cells has been well established, whereas the signaling mechanism of CD40L in T cell costimulation remains unknown. In this study we show that CD28i, a transmembrane splice variant of CD28 costimulatory receptor, complexes with CD40L in human T cells. The cross-linking of CD40L resulted in the coendocytosis of CD28i with CD40L. The tyrosine phosphorylation of CD28i followed the cross-linking of CD40L, and the overexpression of CD28i augmented the c-Jun NH2-terminal kinase, p21-activated kinase 2, and nuclear factor κB activation. These data indicate that CD28i, by functioning as a signaling adaptor, transduces CD40L signaling as well as CD28 signaling in human T cells.
Immune Selection for Altered Antigen Processing Leads to Cytotoxic T Lymphocyte Escape in Chronic HIV-1 Infection
Authors: Draenert Rika , Le Gall Sylvie , Pfafferott Katja J. , Leslie Alasdair J. , Chetty Polan , Brander Christian , Holmes Edward C. , Chang Shih-Chung , Feeney Margaret E. , Addo Marylyn M. , Ruiz Lidia , Ramduth Danni , Jeena Prakash , Altfeld Marcus , Thomas Stephanie , Tang Yanhua , Verrill Cori L. , Dixon Catherine , Prado Julia G. , Kiepiela Photini , Martinez-Picado Javier , Walker Bruce D. , Goulder Philip J.R.
Published: April 2004

Mutations within cytotoxic T lymphocyte (CTL) epitopes impair T cell recognition, but escape mutations arising in flanking regions that alter antigen processing have not been defined in natural human infections. In human histocompatibility leukocyte antigen (HLA)-B57+ HIV-infected persons, immune selection pressure leads to a mutation from alanine to proline at Gag residue 146 immediately preceding the NH2 terminus of a dominant HLA-B57–restricted epitope, ISPRTLNAW. Although N-extended wild-type or mutant peptides remained well-recognized, mutant virus–infected CD4 T cells failed to be recognized by the same CTL clones. The A146P mutation prevented NH2-terminal trimming of the optimal epitope by the endoplasmic reticulum aminopeptidase I. These results demonstrate that allele-associated sequence variation within the flanking region of CTL epitopes can alter antigen processing. Identifying such mutations is of major relevance in the construction of vaccine sequences.
The history of science and the image of science
Authors: Shea W. R.
Published: April 2004

When historians look back on the practice of science at the beginning of the Third Millennium, they will be impressed by brilliant achievements in many fields. We have launched space exploration and made considerable headway in understanding how the brain works. We have cracked the genetic code and opened new means of communication. But historians will also be struck by something else: a cultural gap between scientists and people working in other areas. Funding for science will be seen to have been questioned, and historians will note that support for basic, ‘curiosity–driven’ science declined in favour of supposedly quick–payoff, ‘strategic’ research. They will be driven to ask, ‘What went wrong with the image of science?’ and they will discover that this question was very much in the minds of scientists at the time.
Time and The Royal Society
Authors: Cook A.
Published: April 2004

Fellows of The Royal Society have been concerned with the definition and measurement of time from the first days of the Society. John Flamsteed, F.R.S., ‘Royal Astronomer’, showed that the rotation of the Earth was isochronous and that the length of the solar day varied with the season because the path of the Earth about the Sun was an ellipse inclined to the Equator of the Earth. In the 20th century, D.W. Dye, F.R.S., made quartz oscillators that replaced mechanical clocks, and L. Essen, F.R.S., brought into use at the National Physical Laboratory the first caesium beam frequency standard and advocated that atomic time should replace astronomical time as the standard. The Society supported the development of chronometers for use at sea to determine longitude, and Fellows used the electric telegraph to find longitude in India. Edmond Halley, F.R.S., estimated the age of the Earth from the saltiness of lakes and seas; Lord Kelvin, F.R.S., estimated the rate at which energy was being radiated from the Sun; and Lord Rutherford, F.R.S., showed how the ages of rocks and of the Earth could be found from decay of radioactive minerals in them.
The Royal Society and the microscope
Authors: Ford B. J.
Published: April 2004

From the earliest years of the Society until the start of the Third Millennium, Fellows of the Society have been actively developing the microscope and its uses, from Robert Hooke's pioneering microscopy to the varied forms of the electron microscope. With it they have elucidated the structure of matter, from oolitic limestone to bread, and the nature of living organisms, from microbes in vinegar to current studies of DNA and the folding of proteins.