EXPLORING FOR FAN AND DELTA SANDSTONES IN THE OFFSHORE FALKLANDS BASINS

Four basins surround the Falkland Islands, but only the North Falkland Basin has been drilled; six wells were drilled there in 1998. Although all six wells encountered good quality sandstones, none of them targeted the basin margins, on what are now thought to be the optimum migration pathways associated with the basin's thick lacustrine source rocks. Subsequently, a 3D seismic survey acquired in 2004 was designed to identify potential basin-margin -derived sandstones entering the basin along transfer zones. From this survey, a number of basin-margin -attached fans have been identified; these prograded into lacustrine waters of varying depths. These Early Cretaceous alluvial/fan delta/deep-lacustrine fan systems are interpreted to provide excellent potential reservoir facies as they are intimately associated with thick, mature source rocks. They will provide the focus for the next planned phase of exploration in the North Falkland Basin.
A phase of drilling is also planned for the basins to the south of the Islands, where large deltaic and fan systems, slightly younger than those imaged in the North Falkland Basin, are seen on seismic to prograde from the same Palaeozoic hinterland that produced the older, North Falkland Basin fans.
This paper attempts to show how sedimentary models derived from targeted seismic programmes following initial exploration can be utilised to plan and improve new drilling campaigns in a frontier basin. It presents an analysis of sediment dispersal patterns in basins of marine and lacustrine origin linked to a single hinterland area, and highlights the nature of the relationship between relay ramp/transfer zone development and sediment dispersal patterns in the subsurface.     

Regression of severe atherosclerotic plaque in patients with mild elevation of LDL cholesterol

BACKGROUND: Intensive risk factor reduction in patients with dyslipidemias and coronary atherosclerosis has been shown to result in alterations in coronary artery morphology and reduced clinical events. However, the impact of such interventions in populations with relatively normal levels of low-density lipoproteins (LDL) is unclear. METHODS: To test the hypothesis that intensive risk factor reduction results in angiographic regression in patients with only mildly elevated levels of LDL, 14 patients with angiographically proven coronary atherosclerosis were entered into the University of California Davis Coronary Artery Disease Regression Program and intensively treated with pharmacologic and nonpharmacologic interventions for 2 years. Quantitative angiography was performed prior to and after 2 years of therapy to determine changes in coronary artery diameter. RESULTS: As a result of this program, dietary fat intake was reduced by 58% and LDL fell from 120 +/- 7 mg/dL to 104 +/- 6 mg/dL (p = 0.05). The average diameter of the measured arterial locations (including all 53 stenoses and 292 nondiscrete regions) on study entry was 2.74 +/- 0.05 mm. After 24 months, there was a net increase in arterial diameter (regression) of +0.05 +/- 0.04 mm to 2.81 +/- 0.05 mm (p = 0.01). While there was no significant change in the average diameter of discrete stenoses, all 8 lesions > or = 50% initial diameter narrowing regressed, with a mean diameter change of + 0.2 mm. Conversely, only 1 of 8 mild lesions < or = 20% regressed, while 4 progressed. Intermediate lesions (20% to 50%, n = 37) had balanced progression and regression. CONCLUSIONS: When examined as a continuous variable, there was a significant linear correlation between initial lesion severity (% stenosis) and the extent of regression (mm). Therefore, risk factor reduction (dietary therapy, exercise, psycho-social counseling, and lipid lowering therapy) in patients with only mild dyslipidemia results in angiographic regression of more severe lesions (> 50% initial stenosis), but does not prevent progression of mild lesions (< 20%). These findings demonstrate that intensive risk factor reduction in patients with only mild elevation of lipids beneficially influences the morphology of the most severe lesions.     

Some Aspects of Binding GKS to C++

Aspects of a prototype binding of GKS to the C++ programming language are presented. The binding makes use of classes and derived classes to define GKS concepts such as segments and workstations. Operator overloading is used for some GKS Functions.     

Effects of manufacturing defects on the mechanical properties of carbon fibre reinforced polyethersulphone laminates

The effects of defects on the mechanical properties of carbon fibre reinforced polyethersulphone laminates have been measured. The defects studied were cut fibre plies, omission of polymer films and local delamination produced by the inclusion of foreign matter. Of these it was found that only cut plies had a significant detrimental effect on the strength of a laminate. For specimens with two cut plies, the failure stress, tensile, flexural and compressive in the remaining continuous plies was the same as in the defect-free material, provided that the cut plies were widely separated. However the failure stresses were 15–18% lower in the continuous plies in the specimens containing two cut plies which were more closely spaced and in specimens containing four cut plies.     

Imaging of hippocampal and neocortical neural activity following intravenous cocaine administration in freely behaving cats

We examined spatial-temporal patterns of neural activity, as inferred from 700 nm light reflectance, from the dorsal hippocampus and surrounding neocortex in seven freely behaving cats following 1.5, 2.5, 3.5 and 5.0 mg/kg intravenous cocaine administration. Images were acquired using a new technique which gathered reflected light from cortical and subcortical structures. Cardiac and respiratory patterning, collected simultaneously with optical images, revealed increased rates and diminished variation after intravenous cocaine administration. Cocaine increased reflectance correlates of hippocampal neural activity in a dose-dependent fashion over a 120 min period, with a lengthening time-to-peak effect (22-76 min). The largest dose resulted in an initial decrease, followed by the greatest enhancement in neuronal activity. Correlates of neural activation in the neocortex displayed an inverse dose-response curve to that found in the hippocampus; the time-to-peak effect was shorter (6-43 min) and the maximal change was reduced. Regional patches and bands of activation occurred during the period of the cocaine response, and were more pronounced in the hippocampus than the neocortex. Procaine, administered in a similar dose, slightly increased neural activity for 10 min in both the hippocampus and neocortex, and elicited a small increase in respiration. Cocaine induces a pronounced enhancement of neural activation in the neocortex and dorsal hippocampus; the time course of activation in the hippocampus parallels an increased respiratory pattern and outlasts the neocortical response. We speculate that hippocampal activation may be related to the profound respiratory acceleration found in response to cocaine.     

Renal length in sickle cell disease: observations from a cohort study

Renal length has been measured by ultrasound in 237 subjects with homozygous sickle cell (SS) disease, 147 with sickle cell-hemoglobin C (SC) disease, and in 78 age-matched controls with a normal hemoglobin (AA) genotype. As expected, renal length increased with age in all genotypes but mean length was significantly greater in SS disease compared with SC disease (mean difference 4.3 mm after adjustment for height) and significantly greater in both genotypes than in AA controls (SS/AA difference 9.2 mm, SC/AA difference 5.0 mm after adjustment for height). Examination of relationships between renal length and some hematological indices (hemoglobin, fetal hemoglobin, reticulocyte counts, alpha thalassemia status) in SS or SC disease showed only a significant negative correlation with hemoglobin and positive correlation with reticulocyte count in SS disease. Further analysis suggested that the stronger relationship was between renal length and high reticulocyte count. The mechanism of renal enlargement is unknown although glomerular hypertrophy and increased renal blood volume are likely contributors.     

Studies on the in vitro Release of Ibuprofen from Polyethylene Glycol-Polyvinyl Acetate Mixtures Liquid Filled into Hard Gelatin Capsules

The release of ibuprofen from mixtures of polyethylene glycol (PEG) with polyvinyl acetate (PVAc) has been studied in vitro and complemented by x-ray diffraction measurements, differential scanning calorimetry (DSC), and melting point determinations via hot-stage microscopy (HSM). Results indicate that ibuprofen release can be affected markedly by alteration of the PVAc concentration. The molecular weight of the PEG and the pH of the dissolution medium are also shown to affect the release profile. Visual observation during the drug release process revealed a complex behavior which included emission of liquidlike droplets, formation of a crust around the releasing mass, and/or production of flakes of solid material. This behavior appeared to have a disadvantageous effect on the reproducibility of drug release. Construction of a phase diagram from results of thermal analysis using DSC and HSM indicated the formation of an eutectic mixture with a composition of 35% ibuprofen and 65% PEG 1500 and a melting point of 36°C. The complex behavior of the drug-releasing mass is discussed in terms of this phase diagram. Only the release data for systems containing 4% w/w or more of PVAc could be linearized by plotting against the square root of time whereas data for all of the systems studied could be linearized by first-order plots.     

A conservation principle and its effect on the formulation of Na-Ca exchanger current in cardiac cells

In the rat the exact role of vagal fibers and the interaction between the extrinsic and intrinsic neural system in distention-induced gastrin release are still a matter of debate. Accordingly, the aim of the present study was to examine the contribution of afferent and efferent vagal fibers as well as intrinsic neurons on gastrin response to gastric distention. In anesthetized rats graded gastric distention by 5, 10 and 15 ml saline for 20 min caused a significant volume-dependent increase of plasma gastrin levels by 12+/-6 pg/ml (5 ml saline, n = 8, P =0.05), 26+/-7 pg/ml (10 ml saline, n = 10, P < 0.05) and 37+/-7 pg/ml (15 ml saline, n = 8, P < 0.01 ), respectively. To examine the role of the extrinsic vagal innervation, gastrin response to distention was studied in anesthetized rats after bilateral truncal vagotomy (n = 9) or selective afferent vagotomy following pretreatment with capsaicin (n = 6). Stimulation of gastrin release by 10 ml distention in sham-operated control rats was reversed to an inhibition after truncal vagotomy (26+/-7 vs. -11+/-4 pg/ml; P<0.05) and capsaicin-treatment (37+/-18 vs. -34+/-11 pg/ml; P<0.05). A contribution of cholinergic mechanisms to this vagovagal-mediated stimulation of distention-induced gastrin release was excluded, since atropine (100 microg/kg/h; n = 8) further augmented distention-stimulated gastrin release. Since bombesin/gastrin-releasing peptide (GRP)-neurons contribute to vagally stimulated gastrin secretion, we have examined gastrin response to distention in the presence of the specific bombesin-receptor antagonist D-Phe6-BN(6-13)OMe (400 microg/kg/h: n = 10). This bombesin-antagonist completely reduced distention-stimulated gastrin release in vivo. In contrast, distention of the isolated, extrinsically denervated stomach significantly decreased gastrin release by 13+/-5 pg/min (5 ml saline, n = 8, P < 0.05), 28+/-8 pg/min (10 ml saline, n = 11, P < 0.05) and 35+/-10 pg/min (15 ml saline, n = 8, P < 0.01), respectively, without changing the activity of bombesin/GRP-neurons. Distention-induced decrease of gastrin release was attenuated to 50 percent by atropine (10(-7) M: n = 10) or tetrodotoxin (TTX) (10(-6) M; n = 10), respectively. These data demonstrate, that in anesthetized rats distention-stimulated gastrin secretion depends on the activation of a vagovagal reflex and intrinsic bombesin/GRP-neurons. In contrast distention of the isolated rat stomach inhibits gastrin release in part via intrinsic cholinergic pathways and other as yet unknown mechanisms.     

Predicting compliance with annual follow-up evaluations in persons with spinal cord injury

In this study a representative sample of German acute care hospitals is used to describe the effects of dementia within acute care hospitals. Data from hospital patients above age 60 with the diagnosis dementia (ICD 290, 293, 294 and 310), collected over an observation period of 12 years, are compared with nondemented hospital patients at the same ages. The differences in the average length of stay between demented and nondemented patients are only relatively small in German acute care hospitals. The degree of multimorbidity is higher and hospital infections are more frequent for demented patients. The main differences occur with mortality: demented inpatients of both sexes experience a hospital mortality which is about twice as high as for nondemented patients at the same ages.