Sediment cores were recovered from the New Ireland Basin, east of Papua New Guinea, in order to investigate the late Quaternary eruptive history of the Tabar-Lihir-Tanga-Feni (TLTF) volcanic chain. Foraminifera delta(18)O profiles were matched to the low-latitude oxygen isotope record to date the cores, which extend back to the early part of delta(18)O Stage 9 (333 ka). Sedimentation rates decrease from > 10 cm/1000 yr in cores near New Ireland to similar to2 cm/1000 yr further offshore. The cores contain 36 discrete ash beds, mostly 1-8 cm thick and interpreted as either fallout or distal turbidite deposits. Most beds have compositionally homogeneous glass shard populations, indicating that they represent single volcanic events. Shards from all ash beds have the subduction-related pattern of strong enrichment in the large-ion lithophile elements relative to MORB, but three distinct compositional groups are apparent: Group A beds are shoshonitic and characterised by > 1300 ppm Sr, high Ce/Yb and high Nb/Yb relative to MORB, Group B beds form a high-K series with MORB-like Nb/Yb but high Ce/Yb and well-developed negative Eu anomalies, whereas Group C beds are transitional between the low-K and medium-K series and characterised by flat chondrite-normalised REE patterns with low Nb/Yb relative to MORB. A comparison with published data from the TLTF chain, the New Britain volcanic arc and backarc including Rabaul, and Bagana on Bougainville demonstrates that only Group A beds share the distinctive phenocryst assemblage and shoshonitic geochemistry of the TLTF lavas. The crystal- and lithic-rich character of the Group A beds point to a nearby source, and their high Sr, Ce/Yb and Nb/Yb match those of Tanga and Feni lavas. A youthful stratocone on the eastern side of Babase Island in the Feni group is the most probable source. Group A beds younger than 20 ka are more fractionated than the older Group A beds, and record the progressive development of a shallow level magma chamber beneath the cone. In contrast, Group B beds represent glass-rich fallout from voluminous eruptions at Rabaul, whereas Group C beds represent distal glass-rich fallout from elsewhere along the volcanic front of the New Britain arc. (C) 2003 Elsevier B.V. All rights reserved.

Hydrocarbon gases have been sampled from both cold-seeping and heat-venting areas in the New Ireland fore arc basin in the vicinity of Lihir Island, Highest concentrations of up to 10 mul/l CH4 with a delta(13)C(CH4) value of - 54.9 parts per thousand PDB have been measured in the deep ocean water within a long and narrow deep sea basin located between Edison Seamount and an uplifted structure named "Mussel Cliff". Surface sediments of the seep area were covered with chemoautotrophic deep sea fauna such as Calyptogena species and tube worms, Large authigenic calcite concretions occur in the sediments between 50- and 200-cm sediment depth. The carbon isotopes of the carbonates in the concretions range from - 15 parts per thousand to - 40 parts per thousand PDB indicating a mixture of two CO2 sources: normal marine-inorganic carbon fixed in biogenic shells and CO2 from anaerobe bacterial oxidation processes of methane. Accordingly, C-14-AMS dating suggests that authigenic calcite mineralisation incorporated relatively "young" carbon from methane oxidation, In contrast, the C1/C2 ratio of 234 and the delta(13)C(CH4) value of - 24.1 parts per thousand PDB in the hot hydrothermal vent of Libir Harbour indicates a mixture of a major abiogenic carbon source for methane formation related to magmatism associated with Lihir Volcano. The observed variable fluid characteristics within only 20-km distance between hot hydrothermal-venting and the methane-seeping deep sea area indicates highly variable heat flow situations and/or sediment distributions which control the gas geochemical characteristics in the New Ireland fore are basin. (C) 2002 Elsevier Science B.V. All rights reserved.

Subfossil remains of chironomids, cladocerans and foraminifers found in four sediment cores from the Vejsnaes Basin, Neustadt Bay, Mecklenburg Bay, and Kiel Fjord were analyzed. The faunal assemblages from below the Littorina Transgression horizon represented a rich cladoceran and chironomid fauna typical of freshwater habitats. Above the transgression horizon chydorids disappeared, foraminifers appeared and the diverse chironomid fauna was replaced by an assemblage of three taxa, Clunio marinus, Chironomus salinarius, and Cricotopus/Halocladius, which are typical of brackish/marine conditions.

Using 95 epibenthic δ13C records, eight time slices were reconstructed to trace the distribution of east Atlantic deepwater and intermediate water masses over the last 30,000 years. Our results show that there have been three distinct modes of deepwater circulation: Near the stage 3‐2 boundary, the origin of North Atlantic Deep Water (NADW) was similar to today (mode 1). However, after late stage 3 the source region of the NADW end‐member shifted from the Norwegian‐Greenland Sea to areas south of Iceland (mode 2). A reduced NADW flow persisted during the last glacial maximum, with constant preformed δ13C values. The nutrient content of NADW increased markedly near the Azores fracture zone from north to south, probably because of the mixing of upwelled Antarctic Bottom Water (AABW) from below, which then advected with much higher flux rates into the northeast Atlantic. Later, the spread of glacial meltwater over the North Atlantic led to a marked short‐term ventilation minimum below 1800 m about 13,500 14C years ago (mode 3). The formation of NADW recommenced abruptly north of Iceland 12,800–12,500 years ago and reached a volume approaching that of the Holocene, in the Younger Dryas (10,800–10,350 years B.P.). Another short‐term shutdown of deepwater formation followed between 10,200 and 9,600 years B.P., linked to a further major meltwater pulse into the Atlantic. Each renewal of deepwater formation led to a marked release of fossil CO2 from the ocean, the likely cause of the contemporaneous 14C plateaus. Over the last 9000 years, deepwater circulation varied little from today, apart from a slight increase in AABW about 7000 14C years ago. It is also shown that the oxygenated Mediterranean outflow varied largely independent of the variations in deepwater circulation over the last 30,000 years.

Using 95 epibenthic δ13C records, eight time slices were reconstructed to trace the distribution of east Atlantic deepwater and intermediate water masses over the last 30,000 years. Our results show that there have been three distinct modes of deepwater circulation: Near the stage 3-2 boundary, the origin of North Atlantic Deep Water (NADW) was similar to today (mode 1). However, after late stage 3 the source region of the NADW end-member shifted from the Norwegian-Greenland Sea to areas south of Iceland (mode 2). A reduced NADW flow persisted during the last glacial maximum, with constant preformed δ13C values. The nutrient content of NADW increased markedly near the Azores fracture zone from north to south, probably because of the mixing of upwelled Antarctic Bottom Water (AABW) from below, which then advected with much higher flux rates into the northeast Atlantic. Later, the spread of glacial meltwater over the North Atlantic led to a marked short-term ventilation minimum below 1800 m about 13,500 14C years ago (mode 3). The formation of NADW recommenced abruptly north of Iceland 12,800–12,500 years ago and reached a volume approaching that of the Holocene, in the Younger Dryas (10,800–10,350 years B.P.). Another short-term shutdown of deepwater formation followed between 10,200 and 9,600 years B.P., linked to a further major meltwater pulse into the Atlantic. Each renewal of deepwater formation led to a marked release of fossil CO2 from the ocean, the likely cause of the contemporaneous 14C plateaus. Over the last 9000 years, deepwater circulation varied little from today, apart from a slight increase in AABW about 7000 14C years ago. It is also shown that the oxygenated Mediterranean outflow varied largely independent of the variations in deepwater circulation over the last 30,000 years.

Oceanic plankton (export) productivity contributes to the control of glacial-to-interglacial changes in atmospheric CO 2 concentration. The extent of this contribution may be deciphered from global reconstructions of palaeoproductivity. We quantitatively estimate palaeoproductivity over the last 350 000 years in the eastern equatorial Atlantic, using equations based on foraminiferal assemblages and marine organic carbon accumulation rates; and make qualitative estimates using diatom and radiolarian accumulation rates. These proxydata are calibrated to data on modern primary production. When applied to the same set of marine sediment samples, the various reconstruction techniques produce productivity estimates with similar temporal productivity oscillations and a long-term similar absolute productivity level, suggesting that each provides a good signal of productivity changes.

Possible mechanisms for the 80 ppm reduction of atmospheric CO2 partial pressure during the last glaciation were investigated using the Hamburg Ocean Carbon Cycle Model. The three‐dimensional carbon cycle model is based on the velocity field of the Hamburg Large‐Scale Geostrophic Ocean General Circulation Model and uses the same grid as that model. The horizontal resolution (3.5° × 3.5°) is lower than the length scale of narrow upwelling belts which could not be represented adequately in this study, but the large‐scale features of the ocean carbon cycle are reproduced rather well. Sensitivity experiments were carried out to investigate the role of chemical and biological parameters (nutrient cycling, composition of biogenic particulate matter, CO2 solubility) and different circulation regimes for the atmospheric CO2 content. The model responses were compared to deep‐sea sediment core records and ice core data from the last glaciation. Each experiment was compared with observed average tracer patterns during 18–65 kyr B.P. It was found that none of the sensitivity experiments alone could explain all observed tracer changes (atmospheric pCO2, Δδ13Cplanktonic‐benthic, δ13Cbenthic differences, CaCO3 corrosivity indices) simultaneously, even in a qualitative sense. Thus according to the model none of the scenarios tested proves to be completely acceptable. The residual discrepancies between the observed and modeled tracer records can probably be attributed to the as yet inadequate reconstruction of the glacial ocean circulation. It is therefore suggested that more effort should be devoted to realistically reproducing the ice age ocean circulation field making use of the forthcoming glacial radiocarbon data base. The residuals between the realistically modeled and observed carbon cycle tracers (δ13C, CaCO3 saturation) should then reveal more clearly the real cause for the observed pCO2 decrease in the glacial atmosphere.

In this article I would like to describe a means of displaying graphically (in real time) intensity of light against he corresponding light-sensor position. The quality and visual effect of the on-screen experimental results make the finished system a potentially very useful teaching/learning aid and as such worth reporting. Moreover the system includes elements of basic physics and electronics, as well as computer interfacing display and analysis; such that it illustrates rather nicely the possibilities for integration of CDT and physics. This process of integration or at least fudging of the boundaries is beginning to happen in many schools (Woolnough et a1 1988). With that in mind I decided to include the specifications which led to our final design in the hope that they might act as a stimulus for a design project. This kind of project would be just as appropriate (at different levels of complexity) for students studying GCSE as for those embarked on a degree course.

The theoretical rates of deposition for fine sediments over the last 10 ka have been deduced and plotted for the Kieler Bucht. Assumptions are that the bay has remained as a closed sedimentary system, and that the fine sediments deposit in water deeper than 10 m. A sharp peak of sedimentation activity is indicated between 7.5 and 8.5 ka B.P. with low rates prior to 9.5 ka and since 6 ka. Comparison of rates obtained from dated cores extracted from different parts of the Kieler Bucht with the theoretical curve shows general conformity, and confirms that peak sedimentation rates exceeding 3 mm/a, as averaged over 100–200 years, occurred between 8 and 9 ka, with the suggestion of a minor activity peak between 3 and 4 ka. The overall consistency supports the view that the bay has acted essentially as a closed sedimentary basin during the Holocene marine transgression and subsequently.

Congenital complete heart block has been associated with collagen vascular disorders. Many etiologies have been proposed for the myocarditis that develops and results in the complete heart block. Transplacental antibody transfer--specifically, antibodies to tissue-soluble ribonuclear protein antigen-A--has been implicated as the etiology of the myocarditis. This case supports the association of this antibody while suggesting that viral infection may serve as an initiator of the autoimmune destruction. Also, fetal viral infection alone must be considered a possible cause of congenital complete heart block.

Journal of Clinical UltrasoundVolume 11, Issue 6 p. 336-338 Case Report Early second trimester sonographic diagnosis of achondrogenesis D. Graham MD, FRCS(C), Corresponding Author D. Graham MD, FRCS(C) Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorJ. Tracey RT, RDMS, J. Tracey RT, RDMS Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorK. Winn MD, K. Winn MD Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorV. Corson MS, V. Corson MS Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorR. C. Sanders MD, FRCR, R. C. Sanders MD, FRCR Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this author D. Graham MD, FRCS(C), Corresponding Author D. Graham MD, FRCS(C) Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorJ. Tracey RT, RDMS, J. Tracey RT, RDMS Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorK. Winn MD, K. Winn MD Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorV. Corson MS, V. Corson MS Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this authorR. C. Sanders MD, FRCR, R. C. Sanders MD, FRCR Departments of Gynecology and Obstetrics, Department of Diagnostic Radiology and Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205Search for more papers by this author First published: August 1983 https://doi.org/10.1002/jcu.1870110613Citations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume11, Issue6August 1983Pages 336-338 RelatedInformation

Advances in ultrasound technology permit the early prenatal diagnosis of ever more fetal anomalies. With this knowledge, perinatologists are faced with new, perplexing management decisions. We report the following cases to emphasize the role ultrasound can play in the management of fetal abnormalities in utero

Cystic adenomatoid malformation of the lung (CAM) is an uncommon malformation in which normal tissue is replaced by cysts of various sizes. This malformation may be diagnosed prenatally with ultrasound by visualization of cystic masses in the fetal chest, which may occur in association with fetal hydrops. Three cases of fetal hydrops secondary to cystic adenomatoid malformation of the lung are described; in one case cystic lesions in the chest were clearly demonstrated.

Sonography has proved of great benefit in the diagnosis and management of certain fetal structural anomalies, including encephalocele. Active intervention may be guided by real-time sonography. It is considered that prenatal management will become increasingly common for a number of such anomalies.