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Summary The motivation of this paper is to predict the water saturation (Sw) trend when away from the well, as one of the elements in determining the hydrocarbon volume and commerciality is the Sw. The Sw can be estimated from the resistivity that being derived from the wireline log (at well location) and electromagnetic (EM) data for field coverage away from the well. An example of the EM data is the controlled source electromagnetic (CSEM). However, the limited availability of EM data coverage in Malaysia has led to this study of evaluating an alternative seismic based approach to predict Sw trend away from well using seismic data. An improvised methodology has been developed to predict the 3D seismic-driven Sw_trend by integrating elastic properties and machine learning technique which allows the prediction of hydrocarbon saturation across the field. The generated 3D seismic-driven Sw_trend is validated by 14 blind test wells, where the results are promising. The methodology allows interpreter to visualize and characterize the distribution of the hydrocarbon saturation across the field, and helps to differentiate between the commercial hydrocarbons from the residual which is essential for economic evaluation and well planning

BACKGROUND Recessive forms of congenital ichthyosis encompass a group of rare inherited disorders of keratinization leading to dry, scaly skin. So far, 13 genes have been implicated, but there is a paucity of data on genotype-phenotype correlation in some populations. OBJECTIVES We compiled an English cohort of 146 individuals with recessive ichthyosis and assessed genotype-phenotype correlation. METHODS Deep phenotyping was undertaken by history-taking and clinical examination. DNA was screened for mutations using a next-generation sequencing ichthyosis gene panel and Sanger sequencing. RESULTS Cases were recruited from 13 National Health Service sites in England, with 65% of patients aged < 16 years at enrolment. Pathogenic biallelic mutations were found in 83% of cases, with the candidate gene spread as follows: TGM1 29%, NIPAL4 12%, ABCA12 12%, ALOX12B 9%, ALOXE3 7%, SLC27A4 5%, CERS3 3%, CYP4F22 3%, PNPLA1 2%, SDR9C7 1%. Clinically, a new sign, an anteriorly overfolded ear at birth, was noted in 43% of patients with ALOX12B mutations. The need for intensive care stay (P = 0·004), and hand deformities (P < 0·001), were associated with ABCA12 mutations. Self-improving collodion ichthyosis occurred in 8% of the cases (mostly TGM1 and ALOX12B mutations) but could not be predicted precisely from neonatal phenotype or genotype. CONCLUSIONS These data refine genotype-phenotype correlation for recessive forms of ichthyosis in England, demonstrating the spectrum of disease features and comorbidities, as well as the gene pathologies therein. Collectively, the data from these patients provide a valuable resource for further clinical assessment, improving clinical care and the possibility of future stratified management. What's already known about this topic? Recessive forms of ichthyosis are rare but often difficult to diagnose. Mutations in 13 genes are known to cause recessive forms of ichthyosis: ABCA12, ALOX12B, ALOXE3, CERS3, CYP4F22, LIPN, NIPAL4, PNPLA1, SDR9C7, SLC27A4, SULT2B1, ST14 and TGM1. Some phenotypic features may associate with certain gene mutations, but paradigms for genotype-phenotype correlation need refining. What does this study add? The genotypic spectrum of recessive ichthyosis in England (based on 146 cases) comprises TGM1 (29%), NIPAL4 (12%), ABCA12 (12%), ALOX12B (9%), ALOXE3 (7%), SLC27A4 (5%), CERS3 (3%), CYP4F22 (3%), PNPLA1 (2%) and SDR9C7 (1%). New or particular phenotypic clues were defined for mutations in ALOX12B, ABCA12, CYP4F22, NIPAL4, SDR9C7 and TGM1, either in neonates or in later life, which allow for greater diagnostic precision. In around 17% of cases, the molecular basis of recessive ichthyosis remains unknown.

Aim Placement of a transjugular intrahepatic porta-systemic shunt (TIPS) is a therapeutic option for the management of bleeding esophageal varices. However, the procedure is associated with an increased risk of portal-systemic encephalopathy (PSE). In this study, a two-stage modification of the standard TIPS technique was introduced for the management of variceal bleeding in cirrhotic patients with a high risk of PSE before liver transplantation. Methods The modified procedure was applied to four patients with cirrhosis, portal hypertension, and ascites. Two had a history of encephalopathy after variceal bleeding; the other two were encephalopathic at the time of the first stage of the modified procedure. In the first stage, a 6-mm diameter intrahepatic shunt was created using a Palmaz-Schatz stent. One month later, in the second stage, the lumen of the shunt was expanded to a diameter of 10 mm. Results Both stages of this TIPS procedure were undertaken without any associated adverse events. In particular, neither stage was followed by a deterioration of neurologic status. From completion of the second stage to undertaking orthotopic liver transplantation (a period of 2 to 6 months), no rebleeding from esophageal varices occurred. Conclusions A two-stage TIPS procedure to reduce portal hypertension enables a more gradual adaptation to post-TIPS hemodynamic and metabolic changes than occurs after creation of a conventional TIPS. A two-stage TIPS procedure may be the method of choice for treating bleeding from esophageal varices in patients who have a high risk of developing PSE and give them a chance for liver transplantation.

Increased opioidergic neurotransmission in the brain appears to contribute to the pruritus that complicates cholestasis and certain non-cholestatic chronic liver diseases. Opiate antagonists have been shown to decrease scratching activity in patients with the pruritus of cholestasis. Initiation of oral administration of an orally bioavailable opiate antagonist may precipitate a florid opioid-withdrawal-like reaction in patients with pruritus complicating cholestasis. Such reactions can be minimized, or avoided completely, by cautiously infusing naloxone before giving small oral doses of an orally bioavailable opiate antagonist. The infusion rate of naloxone should initially be very low; it should be increased gradually and stopped when a rate known to be associated with opioid antagonist effects has been attained. Oral therapy with an opiate antagonist can then be initiated.

The purpose of this study was to investigate the effects of intrastriatal blockade of GABA(A) receptors on dopamine D(1)/D(2) receptor interactions in the intact rat striatum. Muscarinic receptors mediate the ability of the D(2) receptor antagonist, eticlopride, to block an increase in striatonigral neuropeptide messenger RNA stimulated by the full D(1) agonist, SKF-82958. However, because D(2) receptor antagonists activate striatopallidal neurons, it is possible that increased GABA release from local medium spiny axon collaterals also contributes to the ability of eticlopride to block the effects of SKF-82958. This hypothesis was addressed by infusing the GABA(A) receptor antagonist, bicuculline, into the dorsal striatum in rats treated with eticlopride and SKF-82958. In contrast to the actions of the muscarinic antagonist, scopolamine, bicuculline did not affect the increase in behaviors induced by SKF-82958 or the ability of eticlopride to block them. Quantitative in situ hybridization demonstrated that bicuculline did not significantly affect basal preprodynorphin messenger RNA, nor did it affect the ability of eticlopride to decrease SKF-82958-induced preprodynorphin messenger RNA. However, the level of the preprodynorphin hybridization signal in bicuculline plus SKF-82958-treated rats was significantly lower than in saline plus SKF-82958-treated rats. In contrast, bicuculline, eticlopride or SKF-82958 by themselves increased basal preproenkephalin messenger RNA. However, there was no significant interaction among bicuculline, eticlopride and SKF-82958 on preproenkephalin messenger RNA levels.These data indicate that blockade of striatal GABA(A) receptors has only a subtle effect on acute dopamine agonist-induced changes in gene expression. These results are discussed in the context of local intrastriatal interactions.

Discusses a way to optimize both the topology and the numerical parameters of an antenna design. The approach relies on an "antenna language" to define how antennas are constructed, and a genetic algorithm to create new designs using this language. The grammatical rules of a language can be very vague or very specific, depending on the purpose of the designer. With a vague grammar, genetic algorithms search a very large design space, and can occasionally find unexpected solutions to a design problem. Other times, they completely fail to find a reasonable solution because of the vastness of the search space. In this case, including knowledge about the problem into the grammar narrows the search to a region expected to yield good results. This yields more conventional design solutions that usually perform reasonably well. In an example, two languages were used to design a linear antenna array. The general language allowed a wide variety of designs, while the Yagi-log language confined the search to topologies known to perform well. The performance of the antennas produced by both languages was superior to that of a conventional log-periodic design. Further, the Yagi-log design was more fit than the unconventional design from the general language, illustrating the benefits of including knowledge in the grammar.

A method of using genetic algorithms to optimize the element spacing and lengths of Yagi-Uda antennas is presented. A method of moments code, NEC2, performs the task of evaluating each of the antenna designs generated by the genetic algorithm (GA) during the optimization process. To illustrate the capabilities of the method, the length and spacing of several Yagi-Uda antennas are optimized for various performance characteristics. The results are compared to published results from other optimization techniques and to well-designed equally spaced arrays.

The development of small-field-of-view, breast-optimized, γ-camera designed for breast scintigraphy has resulted in improved breast lesion detection—particularly for lesions smaller than 1 cm. However, unlike with the standard γ-camera, these images do not include the axilla within the field of view. Methods: Because of the effectiveness of breast scintigraphy using 99mTc-sestamibi in the detection of axillary lymph node metastases, this article describes the development of an axillary imaging protocol for these small-field-of-view systems. Results: In addition, it describes how the improved resolution of these systems affects imaging of the axilla and reports observed, normal variants. Conclusion: Last, several example patient cases are discussed, describing both the impact and the limitations of this imaging protocol.

Breast-specific gamma-imaging (BSGI), also known as molecular breast imaging, is breast scintigraphy using a small-field-of-view gamma-camera and (99m)Tc-sestamibi. There are many different types of breast cancer, and many have characteristics making them challenging to detect by mammography and ultrasound. BSGI is a cost-effective, highly sensitive and specific technique that complements other imaging modalities currently being used to identify malignant lesions in the breast. Using the current Society of Nuclear Medicine guidelines for breast scintigraphy, Legacy Good Samaritan Hospital began conducting BSGI, breast scintigraphy with a breast-optimized gamma-camera. In our experience, optimal imaging has been conducted in the Breast Center by a nuclear medicine technologist. In addition, the breast radiologists read the BSGI images in correlation with the mammograms, ultrasounds, and other imaging studies performed. By modifying the current Society of Nuclear Medicine protocol to adapt it to the practice of breast scintigraphy with these new systems and by providing image interpretation in conjunction with the other breast imaging studies, our center has found BSGI to be a valuable adjunctive procedure in the diagnosis of breast cancer. The development of a small-field-of-view gamma-camera, designed to optimize breast imaging, has resulted in improved detection capabilities, particularly for lesions less than 1 cm. Our experience with this procedure has proven to aid in the clinical work-up of many of our breast patients. After reading this article, the reader should understand the history of breast scintigraphy, the pharmaceutical used, patient preparation and positioning, imaging protocol guidelines, clinical indications, and the role of breast scintigraphy in breast cancer diagnosis.

Summary We report 3 cases of poorly differentiated tumors of the small bowel with histological, immunohistochemical, and ultrastructural studies. The patients were male, aged 45, 57, and 63. In all 3 cases, histological features of spindle cell, epithelioid cell and giant cell areas favoured a diagnosis of carcinoma, although a malignant stromal tumor could not be firmly excluded. Immunohistochemistry demonstrated in the 3 cases a strong expression of both “epithelial” (cytokeratin) and “stromal” (vimentin) markers; one tumor expressed the epithelial membrane antigen, and another one desmin. Electron microscopy showed no specific features in one case. The case positive for desmin demonstrated intracytoplasmic lumina, allowing the diagnosis of carcinoma. In spite of a non-specific immunohistochemical pattern, we finally considered these 3 tumors as of epithelial origin, corresponding to the rare and recently described pleomorphic carcinoma of the small bowel. This report emphasizes the difficult diagnosis of some poorly differentiated tumors, particularly in the gastro-intestinal tract. Such problems had until recently been resolved by ultrastructural and mostly by immunohistochemical studies. However, an increasing number of reports, together with our 3 cases, show unexpected reactivity of tumors with theoretically specific immunoreactions, such as those directed against intermediate filaments. Coexpression of intermediate filaments could be due to cross reactivity of molecules bearing common epitopes, or to the presence of different filaments in the same cell type; recent immunoblotting studies favour this latter hypothesis.

Preface E.A. Jones, A.J. Meijer, R.A.F.M. Chamuleau. Acknowledgements. Part 1: Nitrogen metabolism in relation to liver disease. 1. Novel aspects of nitrogen metabolism in liver disease D. Haussinger, et al. 2. The interorgan exchange of amino acids and ammonia and the effect of plasmapheresis in acute liver failure J.O. Clemmesen, et al. 3. Metabolic consequences of an upper gastro-intestinal bleed in patients with cirrhosis S.W.M. Olde Damink, et al. 4. Citrin deficiency T. Saheki, et al. Part 2: Assessment of overt and minimal hepatic encephalopathy. 5. Assessment of hepatic encephalopathy K. Weissenborn. 6. Evaluation of mental state in a clinical trial of MARS for patients with acute hepatic encephalopathy: comparison of two scales J. Vaquero, et al. 7. Relationship between minimal hepatic encephalopathy and extrapyramidal signs in cirrhotic patients R. Jover, et al. 8. Evaluation of visual focus in cirrhotic patients S. Schiff, et al. 9. Detection of minimal hepatic encephalopathy: EEG spectral analysis vs. cognitive evoked potentials P. Valenti, et al. 10. Analysis of critical flicker frequency threshold in hepatic encephalopathy: dynamics and cortical activations G. Kircheis, et al. 11. Cortical origin of mini-asterixis in hepatic encephalopathy L. Timmermann, et al. 12. Imaging studies in hepatic encephalopathy B. Ahl, et al. 13. Subclinical and overt hepatic encephalopathy - etection and treatment control by proton magnetic resonance spectroscopy (1H-MRS) H.G. Hass, et al. Part 3: Animal models of acute liver failure.14. Long-term observations on rats with thioacetamide-induced hepatic failure W. Hilgier, et al. 15. Reversal of Fischer's ratio in an anaesthetised porcine model of acute liver failure K.J. Dabos, et al. Part 4: Neuropsychiatric dysfunction in chronic liver disease. 16. Experience with neuropsychiatric complications of interferon-based therapy for chronic viral hepatitis K.D. Mullen. 17. Cognitive effects of long-term interferon treatment for chronic viral hepatitis E. De Toni, et al. 18. Is fatigue of cholestasis mediated by altered central serotoninergic neurotransmission? T. Celik, et al. 19. Reduced pallidal magnetisation transfer ratios are associated with fatigue in pre-cirrhotic patients with primary biliary cirrhosis D.M. Forton, et al. Part 5: Pathophysiology of hepatic encephalopathy. 20. Pathogenesis of hepatic encephalopathy K.D. Mullen. 21. Effect of blood plasma components from patients with hepatic encephalopathy on electrophysiological activity of primary frontal cortex networks in vitro J. Loock, et al. 22. Hyperammonemia and liver failure alter signal transduction associated with glutamate receptors and modulation of guanylate cyclase by nitric oxide R. Corbalan, et al. 23. Increased cerebral and peripheral vasodilation, and whole body nitric oxide production after insertion of a transjugular intrahepatic portal-systemic stent in patients with cirrhosis R. Jalan, et al. 24. Concomitant changes in melatonin metabolism and in hypothalamic histamine in rats with a portacaval anastomosis V. Lozeva-Thomas, et al. 25. Brain energy metabolism in acute liver failure: studies using NMR spectroscopy

This paper presents test results on safety shields conducted in accordance with ASTM PS 57 and PS 58 methods, utilizing the same equipment, fault current and duration as in testing of flame retardant fabrics. Safely shields on hot sticks were subjected to power arcs with fault current of 15.4 kA for 22 to 30 cycles. The test results show that the safety shield provides protection from the electric arc to the user and will limit injuries caused by radiant bursts of heat energies and by arc blast shock wave explosions that contain flying fragmentation particles. In addition to test results, the paper also covers safety issues dealing with protection of workers from electric arcs and field experience in using the safety shield.

We report a patient with concurrent superficial carcinomas of the esophagus and stomach. The tumors occurred in a 68-year-old woman. The esophageal tumor was an intramucosal squamous cell carcinoma, and the gastric tumor an intramucosal adenocarcinoma, type III in the Japanese classification of early gastric cancer. This is the first reported case of associated superficial esophageal and gastric cancers originating from a Western country. Such an association may be more frequent than realized, and therefore it is important to examine both the stomach and esophagus if a patient has one of these tumors.

Arsenic(V) and arsenic(III) can be separated, by ion-exclusion chromatography, in solutions containing iron and sulphuric acid. Iron is removed by ion-exchange before the speciation of arsenic, with phosphoric acid as the eluent. The separated arsenic(V) and arsenic(III) are measured spectrophotometrically in the ultraviolet region at a wavelength of 195 mn. Arsenic(V) and arsenic(III) can be determined at concentrations ⩾3 mg/1. The relative standard deviations are 1.3% for arsenic(V) and 0.9% for arsenic(III), at the 10 mg/1. level. The time required for the separation of the inorganic arsenic species is 11 min.

Sir, In their recent editorial on politics and health, Barr et al. suggest that ‘technical medical interventions play only a minor role in affecting the health of populations’.1 Two of the statements that they made to provide support for …

The elastic moduli of single-crystal MgF2 have been determined by the ultrasonic pulse superposition technique as a function of temperature from T=298−650° K. These new data are consistent with those obtained by other ultrasonic pulse techniques at and below room temperature and agree favourably with polycrystalline data above room temperature. The elastic moduli (c) are represented by quadratic functions in T over the experimental temperature range with the curvature in the same sense for all the moduli. For the rutile-structure fluorides and oxides, evaluation of the temperature derivatives of the elastic moduli at constant volume indicates that the dominant temperature effect is extrinsic for (∂K S /∂T) P and intrinsic for (∂μ/∂T) P , where K S and μ are the isotropic bulk and shear moduli, respectively. There appears to be no simple relationship between (∂c/∂T) P and crystallographic parameters for the rutile structure, and |(∂c/∂T) P | for the fluorides is in general very much lower than the corresponding |(∂c/∂T) P | for the oxides. For the pair of compounds MgF2-TiO2, there is no evident analogue relationship for high-temperature elastic properties.

The distribution coefficients are given for the noble metals and associated base metals between S-(1-decyI)-N, N'-diphenylisothiouronium (DDTU) in diisobutyl ketone and aqueous solutions containing varying molarities of hydrochloric acid. DDTU is a satisfactory reagent for the extraction of noble metals as a group from most of the associated base metals. Base metals such as iron(III), tin(II), and selenium(IV), which are co-extracted, can be removed from the organic phase by washing with 0.1 M hydrochloric acid; this affects only the recovery of iridium. Although the noble metals cannot be recovered from the organic phase by back-extraction, direct measurement in the organic phase is possible in ths presence of zinc dibenzyldithiocarbamate added as a releasing agent. The final solution for analysis contains 6 mg of additive per 10 ml of solution.

A calculation is made of the heat transferred from a metal surface to liquid He 4 by resonant states sitting on the metal surface, which radiate acoustic energy into the liquid. The results are compared with experimental evidence and satisfactory agreement is obtained. It is argued that the experimentally observed Kapitza conductance varies as θ D −3 and not as θ D −0.8 as is generally assumed.

Fluorides are considered as models for the physical properties of oxides on the basis of Goldschmidt's crystal chemical arguments. The well-established bulk modulus (K)-volume (V) relationship KV = constant is sddddhown to hold for fluorides and oxides belonging to the four isostructural series. The bulk moduli of equivolume oxides and fluorides are scaled as 4S2, where S = ZO/2ZF is the ratio of the effective unit charges and is approximately 77% for all of the crystal structures. The fluorides have distinctly lower melting and Debye temperatures which offers the possibility of using these compounds as models for the high-temperature elastic behaviour of their oxide analogues.

From 1965 to 1972, 19 patients with the Budd-Chiari syndrome were investigated. An underlying diagnosis was made in 10 cases, polycythemia rubra vera being the commonest etiology. Percutaneous liver biopsy confirmed the diagnosis in 18 patients, and in 14 the site of hepatic vein obstruction was defined or its presence suggested by hepatic venography. Hepatic scintiscanning showed predominant central localization of radiocolloid in 7 patients. In another 8 patients this appearance was present in association with other less specific features. These findings were correlated with inferior vena cavography in 13 patients in whom a characteristic narrowing and distortion of the vein throughout its intrahepatic course was noted. In 3 other patients, the vein was found to be occluded. Autopsy evidence in 6 patients suggests that the central concentration of radiocolloid on scintiscanning and the narrowing and distortion of the inferior vena cava were due to disproportionate enlargement of the caudate lobe. Additional studies indicated that the separate venous drainage of the caudate lobe may be preserved when the main hepatic veins are occluded and that hypertrophy of the caudate lobe occurs because of its relatively more efficient perfusion. Demonstration of the enlarged caudate lobe by scintiscanning and inferior vena cavography provides valuable diagnostic support for the Budd-Chiari syndrome.

Trace and minor contents of the lanthanides are determined in geological materials by an ion exchange—inductively coupled plasma spectrometric procedure. Destruction of the mineralogical matrix is accomplished by fusion with potassium bifluoride followed by separation of the rare earths by cation-exchange chromatography using Biorad® 50 W-8X ion-exchange resin. The rare earths are determined quantitatively by introduction into a medium-power N 2 -Ar ICP coupled to a 3.4-m Ebert® spectrograph. Rareearth data for a wide range of reference materials, including new reference silicate, carbonate and phosphate rocks from MINTEK, South Africa, exhibit relatively good agreement with the quoted values.

We have used blastocoel and vegetal pole grafts to investigate the effect of environment on differentiation and movement of animal pole cells of Xenopus. In the blastocoel of embryos earlier than stage 10, fragments of animal pole primarily form mesoderm. The cells are either integrated into normal host tissues or they organize a secondary posterior dorsal axis. If either host or graft is later than stage 9 the graft forms ectoderm and its cells all migrate into the host ectoderm. Inner layer animal cells form sensorial layer; outer cells move to the epidermis. Thus considerable powers of appropriate movement are seen. In the vegetal pole no movement occurs. If the graft is stage 9 or earlier, or the host is stage 10| or earlier, the graft forms mesoderm, including striated muscle in the gut. This shows that muscle can develop in wholly the wrong environment, it suggests that the dorsal inductive signal from mesoderm is rather general in the vegetal mass and suggests that dorsal mesoderm development involves little subsequent adjustability. If the host is stage 11 or later, or the graft later than stage 9, the graft forms epidermis in the gut. This shows that the epidermal pathway of development is also insensitive to environment.

Ultrasonic data for the velocities of a large number of perovskite-structure compounds have been determined as a a function of pressure to 6 kbar at room temperature for polycrystalline specimens hot-pressed at pressures up to 100 kbar in solid-media devices: ScAlO3, GdAlO3, SmAlO3, EuAlO3, YAlO3, CdTiO3, CdSnO3, CaSnO3 and CaGeO3. The elasticity data for these orthorhombic and cubic perovskites define systematic patterns on bulk modulus (KS)-volume (VO) and bulk sound velocity (υφ—mean atomic weight (M) diagrams which are insensitiv to the details of cation chemistry and crystallographic structure. These isostructural trends are used to estimate KS = 2.5 ± 0.3 Mbar and υφ = 7.9 ± 0.4 km/s for the perovskite polymorph of MgSiO3. On a Birch diagram of veloc vs. density, the perovskite data define linear trends which lead to erroneous estimates of velocity for MgSiO3 unless specific account is taken of ionic radius effects in isomorphic substitutions.

The elastic moduli of single-crystal LiF and NaF have been determined by the ultrasonic pulse superposition technique as a function of temperature from T = 298–650° K. These new data are consistent with low-temperature (T < 298° K) data obtained by other ultrasonic pulse techniques and are superior to previous high-temperature data from resonance experiments. The elastic moduli (c) are represented by quadratic functions in T over the experimental temperature range although the curvature is not in the same sense for all modes. For LiF, NaF, MgO and CaO, evaluation of the temperature derivatives of the elastic moduli at constant volume (V) indicates that the elastic moduli are only weakly dependent on T at constant volume. The fluoride—oxide analogue pair LiFMgO both exhibit high-temperature elastic behaviour at approximately the same absolute temperature. Mitskevich's theory and observed KS-V systematics imply that (∂c/∂T)P should be a function of the nearest neighbour distance for rocksalt fluorides and oxides; this result lends further support to a fluorideoxide modelling scheme based on similar ionic radii.

A spectrophotometric flow-injection procedure is described for the determination of sulphate in sodium hydroxide solutions. Sulphate catalyses the reaction between zirconium and methylthymol blue to form a complex measured at 586 nm. Optimal reaction conditions are discussed. The calibration graph is linear over the range 0.05–0.5 g l −1 sulphate with a relative standard deviation of 0.02. The sample throughput is 20 h −1 . Sulphate is easily determined in 1 M sodium hydroxide; the results agree with those obtained by the conventional gravimetric method and by ion chromatography.

Grafting, together with tissue identification by monoclonal antibodies, has been used to study the allocation of Xenopus animal cap cells to the ectodermal or mesodermal lineages. Animal cap cells become responsive at stage and lose responsiveness to mesodermal induction at, or just after, stage (depending on the batch of embryos). The ability of the vegetal yolky cells to induce mesoderm disappears between stages and 11. It is present at stage 6– and may exist before this. The emergence of competence to respond at stage , coupled with the fact that the endoderm is already capable of induction at this stage, suggests that mesodermal induction begins at this point in the intact embryo.

The telecommunications networks managed by the divested Bell operating companies (BOCs/IDCs) are rapidly evolving into digital networks. The authors discuss the major driving forces and characteristics that are shaping operations transition plans and formulate an operations strategy that is designed to position BOCs/IDCs to manage these digital networks. They describe a Bellcore prototype operations system, referred to as the network monitoring and analysis (NMA) system, that has been tested in one of the BOCs. >

The elastic moduli (c) of single crystal KMgF3 have been determined by the ultrasonic pulse superposition technique as a function of temperature from T=298−550 K, and as a function of pressure from P=1 bar−2.5 kbar. Room temperature values of the elastic moduli and their temperature derivatives are consistent with Reshchikova's (1969) values. Comparison with the data for SrTiO3 indicates that, for most of the moduli, 1/c(∂c/∂T) P and (∂c/∂P) T are very similar for the fluoride-oxide analogue pair, KMgF3-SrTiO3. Values of (∂c/∂P) T for KMgF3 are calculated from a simple central force model using parameters determined for KF and are in good agreement with the measured values. The bulk sound velocity-mean atomic weight relationship, vфM1/2=constant, is well obeyed by the fluoroperovskites; comparison with the perovskite oxide data on a log-log plot of vф versus M leads to a value of 70% for the relative effective charge of the oxides with respect to the fluorides.

The elastic moduli of single-crystal CaF2, SrF2 and BaF2 have been determined by the ultrasonic pulse superposition technique as a function of temperature from T = 298 to T = 650°K. These new data are consistent with other data obtained by ultrasonic pulse techniques in the region of room temperature and are superior to previous high-temperature data from resonance experiments. The elastic moduli (c) are represented by quadratic functions in T over the experimental temperature range with the curvature in the same sense for all the moduli. Evaluation of the temperature derivatives of the elastic moduli at constant volume indicates that the dominant temperature effect is extrinsic for (∂KS/∂T)P and intrinsic for (∂μ/∂T)P, where KS and μ are the isotropic bulk and shear moduli, respectively. For the series CaF2SrF2BaF2, |(∂c/∂T)p| decreases with increasing molar volume for all moduli; however there are no theoretical or empirical grounds on which to derive a simple relationship between (∂c/∂T)P and crystallographic parameters.

This paper reports on some experiments on the influence of a number of methods of surface treatment on the Kapitza conductance between copper and He 4 at not very low temperatures. Attention is paid to the magnitude, the temperature dependence, and the reproducibility between different samples. The results are compared with some theoretical predictions.

Summary A case of congenital cystic dilation of the intrahepatic biliary tree is described. The patient presented with biliary stones and cholangitis and was found to have a coincidental renal tubular ectasia. Biliary drainage through a T-tube was grossly in excess of normal and flow was further increased by an infusion of secretin. It is likely that the high resting flow rates arose from the cysts.

Quantitative studies of urea metabolism have been made by a kinetic technique using 13 C urea in 8 patients with hepatocellular disease before and after a 13-day course of prednisolone. After treatment the mean plasma urea concentration was higher in every case, the increases varying between 4 and 22 mg per 100 ml ( P P > 0.05). It is inferred that the liver in patients with hepatocellular disease usually has the capacity to increase the synthetic rate of urea appreciably in response to an appropriate stimulus. The data can be adequately explained in terms of the known effects of corticosteroids on nitrogen metabolism including the catabolic effect of these drugs on protein metabolism in peripheral tissues. The results imply that corticosteroids increase the turnover of nonprotein nitrogenous compounds of small molecular weight, including ammonia, in patients with liver disease.

Infrared intensities have been measured by the Wilson-Wells' pressure-broadening technique for the ν1, ν2, and ν4 bands of COCl2 and CSCl2. Bond moments and effective charges have been calculated from these intensities with the aid of the usual bond moment assumptions and an additional relation derived from equating the vector sum of the bond moments to the permanent electric dipole moment of the molecule. The values of the bond moments and effective charges calculated for these molecules are: COCl2 μCO=3.91 Debyes(C+→O−) μ′CO= 4.08 Debyes/A μCCl=2.91 Debyes(C+→Cl−) μ′CCl= −8.10 Debyes/A CSCl2 μCS=0.697 Debyes (C+→S−) μCS=3.54 Debyes/A μCCl=0.393 Debyes (C+→Cl−) μCCl=−4.21 Debyes/A These values were chosen from the possible solutions of the bond moment equations with the aid of an analysis of the other molecular parameters known for these two molecules. This analysis also serves to help test the applicability of the bond moment assumptions to these molecules.

The inhibitory effect of fluoroacetate on the citric acid cycle is due to the synthesis of fluorocitrate, which is a competitive inhibitor of aconitase (Peters, 1957) . Consequently, citrate accumulates in fluoroacetate poisoned tissues. Margreth and Azzone (1964) have recently reported that rat heart homogenates have a large endogenous fluoroacetate insensitive respiration, and on the basis of studies with metabolic inhibitors concluded that it was largely supported by the utilization of glutamate and glycelytically generated DPNH. The present investigation with the isolated perfused rat heart has failed to substantiate this suggestion. In this paper we report data on the mechanical performance of the heart during fluoroacetate poisoning, and metabolic control points have been identified by applying the cross-over theorem of Chance et al (1958) to the glycolytic system and the citric acid cycle.

The i.r. spectrum of gaseous CF 3 OF from 4000-33 cm −1 and the Raman spectrum of the liquid are interpreted on the basis of C s symmetry and the same general geometrical configuration as CH 3 OH. The twelve assigned fundamental frequencies provide explanation for forty-two of the forty-seven observed overtone and combination bands. A force constant calculation based on these assignments is performed which yields potential constants, potential energy distribution and normal coordinates. Analysis of i.r. band contours yields moments of inertia in agreement with those calculated from assumed geometry. The height of the threefold barrier to internal rotation is calculated to be 395 cm −1 , whereas thermodynamic properties in the temperature range 200–600°K are tabulated.

$^{\ast}$ Present address of E. D'Alessio: Comision Nacional de Energia Atomica. Avenida del Liberator 8250, Buenos Aires, Argentina. Silberman E. and Jones, E.A. Infrared Spectroscopy Laboratory, Fisk University, Nashville, Tennessee, 37203.