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Using a population-based sampling strategy, the National Institutes of Health (NIH) Magnetic Resonance Imaging Study of Normal Brain Development compiled a longitudinal normative reference database of neuroimaging and correlated clinical/behavioral data from a demographically representative sample of healthy children and adolescents aged newborn through early adulthood. The present paper reports brain volume data for 325 children, ages 4.5-18 years, from the first cross-sectional time point. Measures included volumes of whole-brain gray matter (GM) and white matter (WM), left and right lateral ventricles, frontal, temporal, parietal and occipital lobe GM and WM, subcortical GM (thalamus, caudate, putamen, and globus pallidus), cerebellum, and brainstem. Associations with cross-sectional age, sex, family income, parental education, and body mass index (BMI) were evaluated. Key observations are: 1) age-related decreases in lobar GM most prominent in parietal and occipital cortex; 2) age-related increases in lobar WM, greatest in occipital, followed by the temporal lobe; 3) age-related trajectories predominantly curvilinear in females, but linear in males; and 4) small systematic associations of brain tissue volumes with BMI but not with IQ, family income, or parental education. These findings constitute a normative reference on regional brain volumes in children and adolescents.

Extensive results from the commissioning phase of PUEO, the adaptive optics instrument adaptor for the Canada‐France‐Hawaii Telescope (CFHT), are presented and discussed. Analyses of more than 750 images recorded with a CCD and a near‐IR camera on 16 nights in wavelengths from B to H are used to derive the properties of the compensated wavefront and images in a variety of conditions. The performance characteristics of the system are analyzed and presented in several ways, in terms of delivered Strehl ratios, full width half‐maxima (FWHM), and quantities describing the improvements of both. A qualitative description is given of how the properties of the corrected images result from the structure function of the compensated phase. Under median seeing conditions, PUEO delivers essentially diffraction‐limited images at H and K and images with FWHM ∼ 0 \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepac...

Primordial binaries in globular clusters are important both because their properties are an integral part of the description of the stellar population and because they can strongly influence the dynamical evolution of the cluster (see Hut, this volume).

We describe a detailed physical map of human chromosome 11, extending from the distal part of p13 through the entirety of p14 to proximal p15.1. The primary level of mapping is based on chromosome breakpoints that divide the region into 20 intervals. At higher resolution YACs cover approximately 12 Mb of the region, and in many places overlapping cosmids are ordered in contiguous arrays. The map incorporates 18 known genes, including precise localization of the GTF2H1 gene encoding the 62-kDa subunit of TFIIH. We have also localized four expressed sequences of unknown function. The physical map incorporates genetic markers that allow relationships between physical and genetic distance to be examined, and similarly includes markers from a radiation hybrid map of 11. The cytogenetic location of cosmids has been examined on high-resolution banded chromosomes by fluorescence in situ hybridization, and FLpter values have been determined. The map therefore fully integrates physical, genic, genetic, and cytogenetic information and should provide a robust framework for the rapid and accurate assignment of new markers at a high level of resolution in this region of 11p.

To compare a gram protein exchange system (1g=50-mg Phenylalanine) with a unit exchange system (1unit=15-mg Phenylalanine) and its effect on the blood Phenylalanine (Phe) levels and acceptance in the dietary management for children and adolescents with Phenylketonuria.In Phase One, participants were randomised to continue counting Phe unit exchanges (n=8) or changed to counting gram protein exchanges (n=10), using a new diet chart developed in-house. Foods containing less than 20mg Phe per serve were now considered "free." Interim data analysis confirmed no significant deterioration in Phe levels of the study group and the control group was changed to protein counting.In Phase Two, 18 participants were educated to use an updated version of the in-house diet chart - in this version foods containing less than 50mg Phe per serve were considered "free."In both phases, attitudes to PKU and its management were evaluated at baseline and 6months. Phenylalanine and tyrosine levels were measured from filter paper blood spots by tandem mass spectrometry.Phase One: Phe levels over 6months were comparable to pre-study levels (mean Phe pre 366μmol/L+/- 169, mean Phe post change=388μmol/L+/- 160).Phase Two: Four participants had a significant improvement in blood Phe levels, nine showed no significant change and one participant's levels were significantly higher. There was incomplete data on four participants. All participants preferred the freer diet chart.Protein exchanges (foods containing less than 50mg Phe/serve uncounted) are an alternative method of measuring Phe intake in the dietary management of Phenylketonuria.

Heparan sulfate proteoglycans have been implicated in the presentation of a number of secreted signaling molecules to their signal-transducing receptors. We have characterized a gene trap mutation in the gene encoding a heparan sulfate biosynthetic enzyme, heparan sulfate 2-sulfotransferase (HS2ST). Transgenic mice were generated from embryonic stem cells harboring this insertion.lacZ reporter gene activity in heterozygous embryos demonstrates that the gene is expressed differentially during embryogenesis, presumably directing dynamic changes in heparan sulfate structure. Moreover, mice homozygous for the Hs2st gene trap allele die in the neonatal period, exhibiting bilateral renal agenesis and defects of the eye and the skeleton. Analysis of kidney development in Hs2st mutants reveals that the gene is not required for two early events—ureteric bud outgrowth from the Wolffian duct and initial induction of Pax-2 expression in the metanephric mesenchyme. It is required, however, for mesenchymal condensation around the ureteric bud and initiation of branching morphogenesis. Because 2-O-sulfation has been shown to influence the functional interactions of ligands with heparan sulfate in vitro, we discuss the possibility that the Hs2st mutant phenotype is a consequence of compromised interactions between growth factors and their signal-transducing receptors. These data provide the first genetic evidence that the regulated synthesis of differentially glycosylated proteoglycans can affect morphogenesis during vertebrate development.

A catalog of 383 radial velocities for red giants in the globular cluster M22 has been compiled from the literature and from new observations accumulated between 1972 and 1994. This 22-year baseline is the longest available for any sample of globular cluster stars. Using 333 repeat velocities for 109 cluster members, we have carried out a search for spectroscopic binaries with periods in the range 0.2 -- 40 years and with mass ratios between 0.1 and 1.0. Although the velocities for these evolved stars show clear evidence for atmospheric motions, no star is convincingly found to exhibit a velocity variation greater than 7 km/s. By comparing the observed velocity variations to those found in a series of Monte-Carlo simulations, we estimate the cluster binary fraction to be X = 0.01 (circular orbits) and X = 0.03 (thermal orbits). These results are to be compared to the corresponding binary fraction of X = 0.12 for nearby solar-type stars having similar mass ratios and periods. We speculate that both the relative abundances of short- and long-period binaries in globular clusters and the large differences in measured binary fractions for clusters with high binary ionization rates (M22, Omega Cen) compared to those for clusters with low ionization rates (M71, M4, NGC 3201) point to a frequency-period distribution in which soft binaries have been disrupted by stellar encounters. Finally, we note that none of the three CH stars in our survey shows evidence for velocity variations; this is in stark contrast to field CH stars, virtually all of which are binaries. We argue that binaries in M22 which have binding energies similar to field CH stars are unlikely to have been disrupted by stellar encounters and suggest that the cluster CH stars are otherwise normal red giants which lie in the carbon-enriched tail of the cluster metallicity, Comment: 40 pages; TeX and PS figures. Also available at http://www.dao.nrc.ca/DAO/SCIENCE/science.html

Nine probes were isolated from a human chromosome 1 enriched library and mapped to regions of chromosome 1 using somatic cell hybrid lines. One clone, LR67, which mapped to 1q12----q23 detected a BglI RFLP. This probe, as well as 4 other known chromosome 1 markers, alpha-spectrin, Factor XIIIB, DR10 and DR78, were used for linkage studies in 15 Charcot-Marie-Tooth disease (CMT1) families. Close linkage of CMT1 to any of the 5 markers was not indicated. Total lod scores excluded linkage of CMT1 to LR67 and to DR10 at 5 cM or less, to DR78 at 10 cM or less, alpha-spectrin at 15 cM or less and Factor XIIIB at 20 cM or less. Possible linkage, however, was shown between LR67 and CMT1 at a distance of 30 cM. Also linkage at a distance of 5 cM was detected between this probe and alpha-spectrin.

We have determined the orbit and parallax of the Procyon system (F5 IV-V primary and white dwarf secondary) using conventional absolute radial velocities, precise relative radial velocities determined with the hydrogen flouride (HF) absorption-cell technique, and astrometric and visual observations. Our least-squares analysis confirms and strengthens Strand's previous analysis based on more limited material. We derive an absolute parallax of piabs=0.2899 ± 0.0074 arcsec. Our parallax result is in excellent agreement with other parallax investigations based on independent material. If we adopt the latest USNO parallax of piabs=0.2864 ± 0.0023 arcsec, then from our orbital paramters we derive MA=1.751 ± 0.051 solar mass, and MB=0.622 ± 0.017 solar mass. For the derived mass of Procyon A (which is consistent with previous results), it has long been known that the luminosity predicted by stellar interior theory is approximately a factor of two larger than the luminosity derived from observations. The errors in this observed luminosity and the above formal standard errors (i.e., our best estimates of the statistical random errors) in our derived mass are too small to explain this discrepancy. If the observed separation of the binary components has been systematically overestimated by approximately 0.2 arcsec, then the derived mass would be reduced, thus resolving the discrepancy. However, the excellent consistency of the separations measured by Aitken and Barnard for a number of years at different sites argues against this interpretation. The stellar interior theory of Procyon A may need substantial revision.

The CFHT image stabilizing camera HRCam was used to search for closely spaced images indicative of gravitational lensing among a sample of 101 apparently and intrinsically luminous quasars. No conclusive evidence of multiple imaging due to lensing was found. Although these results are in accord with recent predictions based on standard models of the universe. Turner (1990, ApJ, 365) points out that model universes dominated by a nonzero cosmological constant are not favored. No significant excess of galaxies near the quasars was found, in contrast to the results of Webster et al. (1988, Nature,336), and, more recently, by Drinkwater et al. (1991, ASP Conf. Ser., 21)

High dispersion ultrahigh signal to noise Reticon spectra of Vega were obtained with the coude spectrograph of the 1.2 m telescope. A mean signal to noise ratio of 2500 over the spectral region lambdas from 3825 to 5435 was achieved. Examination of the line profiles confirmed the presence of two different types of profiles which were previously seen in IIIaJ and lower signal to noise Reticon spectra. The profiles of the strong lines are essentially classical rotational profiles with enhanced wings which are slightly stronger than expected while those of weak lines are clearly flat-bottomed resulting in a trapezoidal appearance. A few possible theoretical explanations are presented.

This paper presents CCD photometry for the gravitationally lensed quasar system 2237 + 0305, in optical passbands from B through R, taken over a time period of more than 3 yr. These data provide new information about the probable microlensing event reported by Irwin et al. (1989); the rise time of this feature is approximately 26 days. Four additional independent brightness changes in the quasar images are detected.

Comparison of two extensive series of determinations of the radial velocity of the brighter component of the visual binary 70 Ophiuchi, one made at the Lick Observatory between 1897 and 1932 and the other at the Dominion Astrophysical Observatory between 1966 and 1990, leads to the establishment of a systematic difference between them of about 0.3 km/s and a most probable value for the orbital period of 88.05 y + or - 0.70 y. This value agrees well with that obtained from observations of separation and position angle, of which it is completely independent. Revised orbital elements, based on the spectroscopic observations alone, are also presented.

A complete determination is made of the orbital elements of the visual binary Sigma 2173, by combining new high-dispersion spectroscopic observations with others obtained during passage through the opposite node and with visual and interferometric observations. While the derived parallax of 0.059 arcsec implies masses and luminosities for the components that are in good agreement with spectral types and luminosity classes, they are noted to be problematic from the standpoint of extant theoretical studies of stellar evolution. The two stars of this system are so similar that no difference is distinguishable in spectral type; the brighter of the two stars appears, however, to be the less massive.

Measurements on the rectangular oak supports to three portraits, which include those of Henry VII and of Henry VIII, indicate they were made from the same tree and enable the approximate date at which the panels were used to be determined by dendrochronology. There is the likelihood that a fourth member of the group, previously believed to be Arthur, Prince of Wales, is a copy of an early portrait of Henry VIII.

Details are given of a balanced 21q22q Robertsonian translocation ascertained through infertility in a phenotypically normal male. Chromosome analyses on the proband and his parents showed that the translocation arose as a new mutation. The patient was oligospermic and had a high frequency of morphological abnormalities in his spermatozoa. Meiotic investigations showed a chain trivalent in all primary spermatocytes examined at diakinesis/metaphase I. The testicular histology was normal.

The relationship of body and placental weight with plasma levels of insulin, glucose, glucagon, glucocorticoids and somatomedins in fetal rabbits between 22 days of gestation and term has been investigated. At 22, 24, 26, 28 and 30 days gestation, body and placental weights were strongly correlated and were also significantly correlated with log transformed plasma insulin concentrations in individual fetuses from nulliparous does. At 30 days gestation, mean plasma insulin levels, as well as body and placental weights, were significantly elevated in fetuses from multiparous does (p less than 0.05) and in fetuses whose growth had been increased by surgical reduction in litter size on day 9 of pregnancy (p less than 0.001). Log insulin concentrations in fetuses from multiparous does and in litter-reduced fetuses were also significantly correlated with bodyweight. The correlation coefficient for log insulin and bodyweight in all individual rabbit fetuses at 30 days gestation was 0.69 (p less than 0.001, n = 116). Fetal log plasma glucagon concentrations at 26 and 28 days gestation were negatively correlated with body weight, but were not significantly related at 30 days gestation. Neither glucose nor glucocorticoid concentrations were significantly related to bodyweight in individual fetuses. Plasma somatomedin activity in litter-reduced fetuses at 30 days gestation, was significantly higher (p less than 0.02) than in normal fetuses, but was not significantly correlated with fetal body weight. The observation of strong positive correlation between insulin and bodyweight throughout the last third of gestation reinforces the belief that fetal insulin plays an important role in the regulation of both placental and fetal growth.

Trisomy 8, in mosaic or non-mosaic form is an extremely rare chromosomal condition in man. Liveborn subjects usually present with mental retardation, bone and joint anomalies and a variety of other physical anomalies. The mental retardation associated with the condition is, however, usually moderate compared to that found in other viable human autosomal trisomic conditions. The present report describes a trisomy 8 mosaic male subject with normal IQ and near-normal phenotype, ascertained through infertility. Chromosome studies on peripheral blood lymphocytes reveal a pure trisomy 8 constitution; cultured skin fibroblasts show 46,XY/47,XY+8 mosaicism. At meiosis, the extra No. 8 chromosome is missing from the germ line. The testicular histology indicates a germ cell maturation arrest in many spermatocytes and the patient is severely oligospermic. Biochemical studies to assay levels of glutathione reductase, a red cell enzyme, the gene for which resides in chromosome 8, show increased levels in the trisomy 8 patient compared with controls.

1. Lean (Fa/–) and obese (fa/fa) Zucker rats were adrenalectomized or sham-operated at 18 d of age (3 d before weaning). After weaning the rats were fed ad lib. on semi-synthetic diets containing either a low (8 g/kg) or a high (178 g/kg) proportion of fat. Other groups of sham-operated rats were given the same amount eaten by adrenalectomized animals (restricted intake). Rats were killed at 40 d of age.2. Adrenalectomy reduced the body lipid content of lean and obese rats compared with intact animals fed ad lib. or given a restricted intake. Adrenalectomized obese rats contained more body lipid than intact or adrenalectomized lean rats.3. Sham-operated obese rats given a restricted intake had less body protein than similarly treated lean animals and this phenotypic difference was abolished by adrenalectomy.4. There were no effects of diet on growth or body composition of intact or adrenalectomized rats.5. It is concluded that preweaning adrenalectomy prevented development of the obese phenotype when rats were fed on either diet. Comparison of these results with a previous study, in which adrenalectomized Zucker rats were fed on a stock diet (Fletcher, 1986b), showed, however, that feeding either of the semi-synthetic diets caused greater deposition of body lipid in obese rats.

In maritime areas of north-west Europe the ring-widths of oak form one of two types of pattern. They correspond to growth in geographically discontinuous ecological zones, one at higher altitudes in hilly regions the other in valleys or in lowlands. Slow and fast growth also form separate patterns. The methods for forming and using high quality reference chronologies which enable a large percentage of samples to be matched and dated habe been developed in southern Britain. They should apply in northern France, as should existing chronologies developed in adjacent regions., Dans les zones maritimes du Nord-Ouest de l'Europe, les largeurs des cernes du chêne présentent 1 ou 2 types de disposition caractéristiques. Ils correspondent à la croissance dans des zones écologiques distinctes géographiquement, l'un correspondant aux altitudes supérieures des régions montagneuses, l'autre aux vallées ou aux régions peu élevées. Les croissances lentes et rapides présentent également des dispositions caractéristiques. Des méthodes ont été développées dans le sud de l'Angleterre pour établir et utiliser des chronologies à partir de références sûres, afin de pouvoir synchroniser le plus grand nombre d'échantillons. Elles devraient s'appliquer dans le nord de la France, de même que les chronologies existantes établies dans les régions voisines., Fletcher J. M. Dendrochronology : principles for its application to oak in northern France. In: Revue d'Archéométrie, n°4, 1980. pp. 1-8.

The metabolic fate of 14C derived from radioactively labelled dietary precursors was determined in immature (18- and 25-day-old) lean and obese Zucker rats. This included measurement of 14C incorporated into body lipid, non-essential amino acids and expired CO2. Before weaning (18 days) there was no phenotypic difference between the fates of [14C]palmitate and [14C]-glucose. However, after weaning (25 days) all the precursors studied exhibited an increase in the fraction incorporated into lipid in the obese rat as compared with the lean animal. This was reflected in the fate of acetyl-CoA in the tricarboxylic acid cycle. There was little phenotypic difference in the fraction of leucine or valine catabolized. The results presented here suggest that the high rate of lipogenesis found in the obese rat is supported by carbon from all the dietary precursors studied. It is also argued that the decreased protein deposition found in the obese rat is not caused by the high rate of lipogenesis removing precursors for protein synthesis, as has been suggested elsewhere [Cleary, Vasselli & Greenwood (1980) Am. J. Physiol. 238, E284-E292].

We show that chromosome-mediated gene transfer can provide an enriched source of DNA markers for predetermined, subchromosomal regions of the human genome. Forty-four human DNA recombinants isolated from a HRAS1-selected chromosome-mediated gene transformant map exclusively to chromosome 11, with several sublocalizing to the Wilms tumor region at 11p13. We present a detailed molecular map of the deletion chromosomes 11 from five WAGR (Wilms tumor/aniridia/genitourinary abnormalities/mental retardation) syndrome patients, three of which are at the limits of cytogenetic resolution but shown here to be molecularly distinguishable and overlapping. We can define ten distinct regions of the short arm of chromosome 11, five of which subdivide band 11p13. We also map two independent 11p13 translocation breakpoints to within the smallest region of overlap defined by the WAGR deletions. The first comes from a patient with familial aniridia, and the second from a patient with Potter facies and genitourinary dysplasia. The close similarities in map location and affected cell lineage for Wilms tumor and genitourinary dysplasia suggest that they may be alternative manifestations of mutation at the same locus.

We have isolated a DNA segment absent from all the constitutionally deleted chromosomes 11 of our patients with Wilms tumor. This marker separates two balanced translocations that break in band 11p13: the distal one associated with aniridia (AN2), and the proximal one with genitourinary dysplasia (GUD). The GUD breakpoint maps within the smallest region of overlap (SRO) for the Wilms tumor (WT) gene locus, thus strengthening the previous suggestion of an association between Wilms tumor and other abnormalities of the genitourinary system. The 11p13 translocation breakpoint associated with T-cell acute lymphatic leukemia (T-ALL) is centromeric to the SRO and separated from the WT locus by at least one known gene. This region of the human genome (11p13) is rich in CpG islands that potentially identify genes, some of which may be involved in the various phenotypes associated with the WAGR syndrome. This is consistent with the proposition that the majority of human genes are in G-negative bands.

1. Lean (Fa/?) and obese (fa/fa) Zucker rats were adrenalectomized or sham-operated at 19 d of age (3 d before weaning). Injection of corticosterone for 3 d after weaning (1.0 mg/d) was necessary to ensure survival of adrenalectomized fa/fa but not Fa/? rats. Intact and adrenalectomized fa/fa rats had a lower rectal temperature than Fa/? animals before and 3 d after adrenalectomy. The post-weaning survival of adrenalectomized fa/fa rats was enhanced by maintenance at an ambient temperature of 30° rather than 22°.2. Adrenalectomized and sham-operated rats were therefore kept at 30°, fed ad-lib. and killed at 34 d. Adrenalectomy had only small effects on the growth, body composition and appetite of Fa/? rats. The hyperphagia, greater lipid content, reduced protein content and hyperinsulinaemia of fa/fa rats were completely abolished by adrenalectomy.3. Intact fu/fa rats had higher liver glycogen contents and higher activities of the hepatic enzymes tyrosine aminotransferase (EC 2. 6. 1. 5) and acetyl CoA carboxylase (EC 6. 4. 1. 2) than intact Fa/? animals. Adrenalectomy abolished these phenotypic differences.4. Injection of adrenalectomized rats with 1.0 mg corticosterone-21-acetate daily from weaning to 34 d restored the abnormal body composition, hyperphagia, hyperinsulinaemia, higher hepatic glycogen and enzyme activities of fa/fa rats.5. In a second experiment adrenalectomized rats were injected with 1.0 mg corticosterone-21-acetate daily from weaning to 34 d and kept at 22°, fa/fu rats adrenalectomized and injected with corticosterone had a reduced body lipid content compared with intact fa/fa rats but still contained more lipid than intact or similarly treated Fa/? animals.6. In both experiments adrenalectomized Fa/? and fa/fa rats injected daily with corticosterone had the same plasma concentrations of this hormone when killed 3 h after the last injection at 34 d. It is concluded that corticosterone is required for expression of the abnormal appetite, hyperinsulinaemia and body composition of the fa/fa rat.

A systematic survey of 1599 male patients attending a subfertility clinic has shown that 2.2% were chromosomally abnormal. This frequency was approximately five times higher than that found among the normal male population. The majority of chromosome abnormalities (at least in chromatin-negative males) appeared to be exerting their effect on male fertility through disturbance of spermatogenesis. The contribution made by chromosome abnormalities causing recurrent abortion in wives was negligible. The possible reasons underlying impairment of spermatogenesis in man are discussed in relation to the findings in other species, and the suggestion that some elimination of chromosomally unbalanced gametes occurs from the human male germ line is proposed.

Intact obese rats were hyperinsulinaemic, had higher rates of whole-body fatty acid synthesis, higher activities of hepatic acetyl-CoA carboxylase and tyrosine aminotransferase and a higher hepatic glycogen concentration than intact lean animals. Adrenalectomy abolished all these factors of the obese phenotype. Treatment of adrenalectomized rats with corticosterone for 24 h increased the rate of whole-body fatty acid synthesis to the same extent in both phenotypes, but caused a larger increase in glycogen concentration, tyrosine aminotransferase activity and plasma insulin concentration in obese rats.

It often happens that the empirical observations of chemistry reveal the working of principles which can be easily interpreted in terms of physical theories, but which might have been difficult to predict. One need only mention the question of the nature of valency as one of the most conspicuous examples. For this reason it is useful if problems lying on the border line of physics and chemistry are discussed from both points of view. The present theme is the distribution of energy in molecules and its relation to the phenomena of chemical change. We know that the transference of energy from one molecule to another and, in particular, the accompanying interconversion of translational and internal energy depend upon specific mechanisms which give rise to phenomena of great interest. I need only mention the influence of hydrogen and certain other gases in maintaining the energy distribution in unimoleculer reactions, the variation of the velocity of sound with frequency, due to the finite time required for the establishment of equilibrium in the energy distribution among the internal degrees of freedom, and lastly that curious inability of solvent molecules to degrade the light energy absorbed by fluorescent substances.

In reactions depending on the decomposition of a single substance the general relation between the rate, as represented by the reciprocal of the time of half change, and the initial pressure is given by a curve which at first rises from the origin and then bends round to become parallel to the pressure axis. The point at which the curve becomes horizontal, and the height of the limiting, ordinate depend upon specific constants. Thus, if a molecule suffered a number of alternative decompositions, the total rate of change would be represented by a curve which showed a corresponding number of changes of slope in particular regions of pressure, giving it a segmented appearance. The curves for nitrous oxide and for acetaldehyde show such an appearance, and the decompositions appear to be composite. Yet the products of reaction are the same over the whole pressure range. The same chemical reaction are the same over the whole pressure range. The same chemical reaction thus occurs by mechanisms which differ in some physical way. This can be interpreted by assuming different types of activated molecule which have widely different decomposition probabilities.

The thermal decomposition of formaldehyde has been studied for comparison with the decomposition of other simple aldehydes. In the decomposition of acetaldehyde the kinetics of the reaction have led to the hypothesis of the existence of a limited number of different activated states of the molecule. It was of interest to determine whether the kinetics for the simpler molecule of formaldehyde correspond to a smaller number of modes of activation. Experimental Results The experimental method was that described previously. Formaldehyde vapour was introduced into the reaction vessel by heating paraformaldehyde. To prevent condensation in parts of the apparatus outside the furnance, all these were kept above 100° C with heated nichrome wire, a special high temperature grease being used for the taps. As the reaction was unaffected by the presence of water vapour (Tables I and Ii) elaborate drying of the formaldehyde was not undertaken. Care was taken to avoid traces of air which interfere with the reaction. The vapour first given off from a fresh sample of parahyde which had been in use for some time.

A comparison of the thermal decomposition of methyl alcohol with those of formaldehyde, the ethers, and other compounds of similar structure seems of interest in relation to kinetic problems. Methyl alcohol is known to decompose catalytically in the presence of zinc oxide to formaldehyde and hydrogen at 300° C. The same reaction occurs thermally at a measurable speed between 650° and 750° C. The presence of formaldehyde can be detected by Schryver’s test. Formaldehyde at these temperatures rapidly decomposes into carbon monoxide and hydrogen, so that the resultant equation is CH 3 OH = CO + 2H 2 . Analyses of the end-products of the reaction, made for initial pressures of approximately 200 mm, show that the gas consists entirely of hydrogen and carbon monoxide. The ratios in three analyses were 1·92, 1·83, and 1·85.

Homogeneous thermal gas reactions were at one time tacitly assumed to possess a definite order, unimolecular and bimolecular reactions, for example, being sharply distinguished. The kinetics of the decomposition of acetalde­ hyde, CH 3 CHO = CH 4 + CO, over the pressure range of 100 to 400 mm. were found to satisfy the criterion of a bimolecular reaction, namely, that the reciprocal of the time for half change (1/ t 1/2 ) )plotted against the initial pressure ( p 0 ) gave a straight line inclined to the axes. The line, however, did not pass through the origin, as may be seen in fig. 1 of the present paper. This indicated the presence of some first order reaction, the nature of which was not determined. Subsequently, in accordance with the collision theory of activation and deactivation, it was shown that certain reactions, sometimes called quasiummolecular, change their order from the second at low pressures to the first at high pressures. This apparently was the reverse of the behaviour shown by acetaldehyde.

The value obtained for the difference in radial velocity between components of a visual binary that is unresolved on the spectrograph slit appears to depend, sometimes, on whether the measurement is made visually with a microscope or by means of an oscilloscopic setting device. This apparent dependence has been confirmed by measurement of artificially produced double-lined spectrograms, and disappears for line pairs separated by more than 1.5 or 2 times the half-widths of their components. The dependence arises from blending of the two line profiles. There is some evidence that the results obtained from visual measures are affected by the scale of the image being measured. For this reason, oscilloscope measures are probably to be preferred; although their errors are sometimes larger, they seem to be more consistent. Errors arising from this sort of blending are not sufficient to explain measures of relative radial velocity of the components of some visual binaries, that differ widely from the predictions made from the visual orbits.

The basic gene defect in the autosomal recessive disorder cystic fibrosis has not been identified, and no firm linkage of the disorder to any other marker has been reported. However, a serum protein abnormality present in unaffected heterozygotes as well as in affected homozygotes has been described1, and immunological quantitation of this protein, termed cystic fibrosis antigen, allows the three genotypes to be distinguished2,3. We show here that an immunologically indistinguishable protein is present at high concentrations in granulocytes from normal and cystic fibrosis individuals as well as in myeloid leukaemia cells. Somatic cell hybrids between the mouse myeloid stem-cell line WEHI-TG and myeloid leukaemia cells express cystic fibrosis antigen only when human chromosome 1 is present.

Fusion of human EJ bladder carcinoma cells to mouse C127 cells, with direct selection for tumor growth, gave rise to hybrid cells in which the human chromosome complement had been reduced dramatically, while selectively retaining the activated HRAS1 at chromosome band 11q15. A single-component hybrid retaining only part of human chromosome 11 is described in detail. Our results suggest a novel and general approach for investigating the chromosomal basis of neoplastic change and for subchromosomal mapping of and enrichment cloning for the human genome.

We used mitotic chromosomes isolated from a human EJ bladder carcinoma cell line for morphological transformation of mouse C127 cells. These chromosome-mediated transformants were analyzed for cotransfer of markers syntenic with c-Ha-ras-1 on human chromosome 11. We also used cloned, dispersed human DNA repeats, in a general mapping strategy, to quantitate the amounts and molecular state of human DNA transferred along with the activated c-Ha-ras-1 gene. In situ hybridization was used to visualize the physical state of the transfected human chromatin. The combined use of these various techniques revealed the occurrence of both chromosomal and DNA rearrangements. However, our analysis also demonstrated that, in general, very substantial lengths of DNA are transferred intact. Closely linked markers are likely to cosegregate. Therefore, these transformants should be invaluable sources for the complete molecular cloning of isolated fragments of the short arm of human chromosome 11.

The rates of protein synthesis in skeletal muscle, intestine, liver and in the whole body of immature (18 and 25 days old) lean and obese male Zucker rats were measured. In addition, the rate of deposition of whole-body and skeletal-muscle protein over the period 16-27 days post partum was measured by comparative slaughter and analysis of the composition of the body. At 16 days post partum, lean and obese rats had similar body protein contents, but thereafter the rate of protein deposition in the body and skeletal-muscle mass was decreased in the obese rats. The decrease was particularly marked before 21 days of age, and between 23 and 27 days post partum the fractional rate of protein deposition was the same in lean and obese rats. Of the tissues that were studied, only skeletal muscle had a lower fractional rate of protein synthesis in the obese rats. At 18 days post partum, the decrease in the absolute rate of protein synthesis in skeletal muscle accounted for at least 80% of the decline in protein synthesis in the whole body. After weaning, phenotypic differences in protein synthesis was less marked than at 18 days of age, and skeletal muscle accounted for only 50% of the difference in body protein synthesis between phenotypes. The possibility that a change in the function of the adrenal cortex contributes to differences in protein metabolism between lean and obese Zucker rats is discussed.

Cytological evidence for the existence of a Y-autosomal rearrangement in meiotic cells of Sxr mice has been sought. At peachytene, in silver-stained light microscope spread preparations of XY, Sxr/+ and XO, Sxr/+ spermatocytes, evidence for pairing or association between a possible Y-bearing segment of a specific autosome and a sex chromosome could not, however, be found. Such sex chromosome-autosome associations as were seen were non-specific in nature, and occurred no more often in Sxr mice than in controls.

Genetic linkage, molecular analysis, and in situ hybridization have identified TYR and D11S388 as markers flanking the chromosome 11 breakpoint in a large pedigree where a balanced translocation, t(1;11)(q43;q21), segregates with schizophrenia and related affective disorders. Somatic cell hybrids, separating the two translocation chromosomes from each other and from the normal homologues, have been produced with the aid of immunomagnetic sorting for chromosome 1– and chromosome 11–encoded cell-surface antigens. The genes for two of these antigens map on either side of the 11q breakpoint. Immunomagnetic bead sorting was also used to isolate two stable X-irradiation hybrids for each cell-surface antigen. Each hybrid carries only chromosome 11 fragments. Translocation and X-irradiation hybrids were analyzed, mainly by PCR, for the presence of 19 chromosome 11 and 4 chromosome 1 markers. Ten newly designed primers are reported. The X-irradiation hybrids were also studied cytogenetically, for human DNA content, by in situ Cot1 DNA hybridization and by painting the Alu-PCR products from these four lines back onto normal human metaphases. The generation of the translocation hybrids and of the chromosome 11q fragment hybrids is a necessary preliminary to determining whether a schizophrenia-predisposition gene SCZD2 is encoded at this site.

We have used the Dominion Astrophysical Observatory radial velocity spectrometer on the 3.6m Canada-France-Hawaii telescope to obtain radial velocities, accurate to ~0.8 km/s, for ~20 stars in each of nine globular clusters. The stars are generally within three core radii of the cluster center. The cluster names and metallicities (the latter are averages of values in Zinn and West (1984), Pilachowski (1984), and Webbink (1985)) are given in Table I. This sample includes two clusters with cusps in their surface brightness profiles: NGC 6624 and 6681.

A photoelectric radial velocity spectrometer has been in operation for several years at the coudé focus of the 1.2m telescope of the Dominion Astrophysical Observatory (DAO). The design of this instrument has been described by Fletcher et. al. (1982) and by McClure et al. (1984). These papers discuss the similarities and differences between this spectrometer and others of its type such as that constructed by Griffin and Gunn (1974) at Palomar. The spectrum mask in the present instrument consists of more than 700 transparent slots on an opaque background, representing the spectrum of a K giant star, plus a few slots to coincide with the argon lines in a cadmium-argon discharge tube for use in obtaining comparison arc velocities. By progressively tilting the slots an appropriate amount along the mask and scanning by moving the mask relative to the stellar spectrum at 45° to the dispersion it is possible to retain a spectral match at non-zero velocities. The masks are produced using a standard measuring engine modified with stepping motors controlled by a computer to position and tilt the slots. Since guiding errors are our major source of error we hope to make a significant improvement in this area in the following manner. By inserting an image rotating prism behind the slit a 180° rotation of the slit will occur when the prism is rotated. Although this has not yet been tested, it is hoped that by making this rotation every few scans the effects of guiding errors due to uneven illumination of the slit and collimator will be vastly reduced.

TREE-RING investigations in Europe are largely based on the method initiated by Huber in 1938 at Tharandt (near Dresden)1 by which the widths of the rings are measured and the resulting sequence charted and compared both visually and by computer. In temperate zones such as England and the Low Countries oak panels are ideal for the study of dendrochronology as they were prepared from the butt logs of elite trees of slow and even growth. A panel used as a support for a painting has the added advantage that its edges are accessible2. Since 1971 I have worked on 115 of those used by portrait painters in South-east England or Flanders between 1450 and 1620 (refs 3, 4). The boards (there are more than one on some panels) have an average of 200 rings of mean width 1.5 mm.

THE contrasting magnetic behaviour (Table 1 and Fig. 1) of the α- and β-forms of RuCl3 is of interest in relation to the different types of stereochemical arrangements1 shown by the transition metal halides: it has also allowed the presence of α-RuCl3, produced in the usual method of preparation of β-RuCl3, to be detected. A material, hitherto considered2,3 as yet another form of RuCl3, is now shown to be Ru2IVOCl6 (Table 1), a member of a class of oxide chlorides of binuclear ruthenium in which the average oxidation state of ruthenium changes from +4 through +3.5 to +3.