bluuebunny/crossref_metadata_2025 huggingface dataset:
Nucleotide binding and hydrolysis properties ofNeurospora crassacytosolic molecular chaperones, Hsp70 and Hsp80, heat-inducible members of the eukaryotic stress-70 and stress-90 families
Authors: Ouimet P M , Kapoor M
Published: April 2011

Formation of a hetero-oligomeric complex between Hsp70 and Hsp80 of Neurospora crassa was observed previously by means of chemical crosslinking and enzyme-linked immunosorbent assays (ELISA). The present study documents the effect of nucleotides on the subunit structure of Hsp70 and Hsp80 by crosslinking with bifunctional reagents: glutaraldehyde, dimethyl adipimidate (DMA), and dimethyl suberimidate (DMS). The inter-protomer crosslinking of Hsp80 with DMA and DMS was suppressed by ATP and to a lesser extent by ADP, CTP, and NAD. Crosslinking of purified Hsp70 by glutaraldehyde yielded dimers and higher order oligomers. Binding of ATP, ADP, CTP, and NAD, but not NADH, led to a marked reduction in the yield of oligomers. Similarly, crosslinking by DMA and DMS was suppressed by ADP, ATP, and CTP. Both Hsp70 and Hsp80 exhibited intrinsic ATPase activity. Interestingly, ATP levels exceeding 25 µM resulted in pronounced inhibition of the ATPase activity of Hsp80 and 0.5 mM and 0.25 mM ATP led to a prolonged lag in the reaction. Addition of NAD resulted in the abolition of the lag period. The binding of 2-p-toluidinylnapthalene-6-sulfonate (TNS) to Hsp70 and its displacement by ATP and other nucleotides demonstrated the hydrophobic nature of the nucleotide-binding region.Key words: molecular chaperones; ATPase; Hsp70; Hsp80; Neurospora.
Expression of an enzymatically active polymerase of human hepatitis B virus in a coupled transcription-translation system
Authors: Li Zhi , Tyrrell D Lorne J.
Published: April 2011

Genome replication of hepadnavirus proceeds by reverse transcription from a viral pregenomic RNA template by a virally encoded polymerase that possesses protein-priming, reverse transcriptase, DNA polymerase, and RNase H activities. Characterization of this enzyme has been hampered by failure to purify an active enzyme from virions and difficulties in expressing an active polymerase in heterologous systems. In this study, we constructed human hepatitis B virus polymerase cDNA under the control of a phage T7 promoter and expressed it in a rabbit reticulocyte lysate-coupled transcription-translation system. In vitro site-directed mutagenesis confirmed that the recombinant polymerase cDNA produced three products: a full-length protein (~94 kDa), an internally initiated protein (~81 kDa), and an N-terminal protein (~40 kDa). The in vitro expressed polymerase possessed protein priming activity, as demonstrated by32P-dGTP-labeling of the full size polymerase and the N-terminal portion of the molecule in an in vitro priming assay. The polymerase also exhibited polymerization activity, as detected in an in vitro polymerase assay by incorporation of radionucleotides into acid-precipitable polynucleotides and by synthesis of human hepatitis B virus (HBV) specific DNA with product lengths between 100 and 500 nucleotides. In addition, the polymerase was found to use an RNA sequence bearing HBV DR1/epsilon stem-loop motif as a template for DNA synthesis. Both the protein-priming and the reverse transcription activities of this recombinant polymerase are dependent on the RNA fragment containing the HBV DR1/epsilon stem-loop sequence known to be required for the polymerase activities. The in vitro systems used in this study will be applicable to further functional and biochemical studies of this enzyme.Key words: hepadnavirus, HBV polymerase, protein priming, reverse transcription, rabbit reticulocyte lysate.
cDNA cloning and cadmium-induced expression of metallothionein mRNA in the zebra musselDreissena polymorpha
Authors: Engelken Jens , Hildebrandt Armin
Published: April 2011

Using pooled degenerate oligonucleotides inferred from the N-terminal amino acid sequence of Dreissena polymorpha metallothionein and a Cys-X-Cys motif characteristic for known metallothioneins, a 150-bp metallothionein-specific reverse transcription PCR product was generated. The PCR product was used to screen a Dreissena polymorpha cDNA library, and a complete metallothionein cDNA sequence from Dreissena was identified. Four clones with the identical sequence were detected, supporting the idea of a single metallothionein gene in Dreissena. The sequence contains a 141-bp 5prime untranslated region and a 572-bp 3prime untranslated region with two polyadenylation signals. The coding region spans 219 bp. The deduced amino acid sequence shows 21 cysteine residues present in the metallothionein-typical motifs. Induction studies were performed with 50 µg Cd2+/L for up to 16 days. The exposed mussels show a sevenfold higher metallothionein mRNA level compared with uninduced control mussels.Key words: metallothionein, Dreissena polymorpha, cadmium, induction, mRNA.
Tyr-503 of β-galactosidase (Escherichia coli) plays an important role in degalactosylation
Authors: Penner Robert M , Roth Nathan J , Rob Beatrice , Lay Helga , Huber Reuben E
Published: April 2011

Substitutions for Tyr-503 of β-galactosidase caused large decreases of the activity. Both the galactosylation (k2) and degalactosylation (k3) rates were decreased. Substitutions by residues without transferable protons, caused k3 to decrease much more than k2 while substitutions with residues having transferable protons, caused approximately equal decreases of k2 and k3. Several lines of evidence showed this. The Km values of the substituted enzymes were much smaller than those for the wild type if the substituted amino acid residues did not have transferable protons; this was not the case when the substituted residues had transferable protons. Inhibition studies showed that the Km values were not small because of small Ks values but were small because of relatively small k3 values (compared with the k2 values). The conclusion that the k3 values are small relative to k2 upon substitution with residues without transferable protons is also based upon other studies: studies indicating that the reaction rates were similar with different substrates, studies in the presence of alcohol acceptors, studies showing that the rate of inactivation by 2,4-dinitrophenyl-2-deoxy-2-F-β-D-galactopyranoside decreased much less than the rate of reactivation; studies on burst kinetics, and pH studies. The data suggest that Tyr-503 may be important for the degalactosylation reaction because of its ability to transfer protons and thereby facilitate cleavage of the transient covalent bond between galactose and Glu-537. Key words: β-galactosidase, tyrosine, mechanism, acid catalysis.
Nonlamin components of the lamina: a paucity of proteins
Authors: Chaly Nathalie , Stochaj Ursula
Published: April 2011

Current models of nuclear organization propose that nuclear functions are modulated in part by reversible tethering of chromatin loops to structural elements of the nucleoplasm and the nuclear envelope. Lamins are the best-characterized proteins of the lamina portion of the nuclear envelope and are involved in binding chromatin to the inner nuclear membrane. However, they are not a universal feature of eukaryotic nuclei and do not account fully for the putative functions of the lamina in all organisms. It is possible that nonlamin components of the lamina may substitute for lamins in organisms from which they are absent and modify the properties of lamins during development and the cell cycle. We review the properties of the relatively small number of such components that have been reported, including the young arrest (fs(1)Ya) protein of Drosophila, statin, circumferin, and the MAN antigens. The experimental evidence indicates they are a diverse group of proteins, and that at least some have the potential to modulate the interactions of chromatin, lamins, and the nuclear membranes.Key words: nuclear envelope, lamina, YA protein, statin, circumferin.
Cloning of aSchizosaccharomyces pombehomologue of elongation factor 1 alpha by two-hybrid selection of calmodulin-binding proteins
Authors: Rasmussen Colin , Wiebe Christine
Published: April 2011

This study reports the cloning and characterization of a cDNA encoding elongation factor 1-alpha (EF1alpha) from the yeast Schizosaccharomyces pombe. The cDNA was cloned from an Schizosaccharomyces pombe expression library by a two-hybrid selection for clones encoding calmodulin (CaM)-binding proteins. The predicted protein is highly homologous to mammalian EF1alpha, indicating a strong tendency towards conservation of the primary amino acid sequence. The protein was expressed as a glutathione S-transferase fusion in both bacteria and in Schizosaccharomyces pombe. The bacterial protein was shown by solution assay to compete with CaM kinase II for CaM. The CaM binding domain was localized to the C-terminus of the protein by this method. Expression of full-length EF1alpha in vivo caused an increase in cell cycle length and a decreased rate of growth as evidenced by a lack of elongated cells in slowly dividing cultures. This effect appears to involve CaM binding because a truncation mutant version of EF1alpha lacking the CaM binding domain did not cause cell cycle delay.Key words: calmodulin, two-hybrid selection, calmodulin-binding protein, yeast, cell proliferation.
Fibroblast growth factor-2 stimulates phospholipase Cβ in adult cardiomyocytes
Authors: Tappia Paramjit S , Padua Raymond R , Panagia Vincenzo , Kardami Elissavet
Published: April 2011

Although fibroblast growth factor-2 (FGF-2) plays an important role in cardioprotection and growth, little is known about the signals triggered by it in the adult heart. We therefore examined FGF-2-induced effects on phosphoinositide-specific phospholipase C (PI-PLC) isozymes, which produce second messengers linked to the inotropic and hypertrophic response of the myocardium. FGF-2, administered by retrograde perfusion to the isolated heart, induced an increase in inositol-1,4,5-trisphosphate levels in the cytosol, as well as an increase in total PI-PLC activity associated with sarcolemmal and cytosolic fractions. Furthermore FGF-2 induced a time-dependent elevation in cardiomyocyte membrane-associated PLC gamma1 and PLC β1 activities, assayed in immunoprecipitated fractions, and moreover, increased the membrane levels of PLC β1 and PLC β3. Activation of PLC β is suggestive of FGF-2-induced cross-talk between FGF-receptor tyrosine kinase and G-protein-coupled signaling in adult cardiomyocytes and underscores the importance of FGF-2 in cardiac physiology.Key words: FGF-2, signal transduction, PLC gamma, PLC β, cardiomyocytes.
Anion binding characteristics of the band 3 / 4,4'-dibenzamidostilbene-2,2'-disulfonate binary complex: Evidence for both steric and allosteric interactions
Authors: Salhany James M
Published: April 2011

A novel kinetic approach was used to measure monovalent anion binding to better define the mechanistic basis for competition between stilbenedisulfonates and transportable anions on band 3. An anion-induced acceleration in the release of 4,4prime-dibenzamidostilbene-2,2prime-disulfonate (DBDS) from its complex with band 3 was measured using monovalent anions of various size and relative affinity for the transport site. The K1/2values for anion binding were determined and correlated with transport site affinity constants obtained from the literature and the dehydrated radius of each anion. The results show that anions with ionic radii of 120-200 pm fall on a well-defined correlation line where the ranking of the K1/2values matched the ranking of the transport site affinity constants (thiocyanate < nitrate equivalent to bromide < chloride < fluoride). The K1/2values for the anions on this line were about 4-fold larger than expected for anion binding to inhibitor-free band 3. Such a lowered affinity can be explained in terms of allosteric site-site interactions, since the K1/2values decreased with increasing anionic size. In contrast, iodide, with an ionic radius of about 212 pm, had a 10-fold lower affinity than predicted by the correlation line established by the smaller monovalent anions. These results indicate that smaller monovalent anions have unobstructed access to the transport site within the band 3 / DBDS binary complex, while iodide experiences significant steric hindrance when binding. The observation of steric hindrance in iodide binding to the band 3 / DBDS binary complex, but not in the binding of smaller monovalent anions, suggests that the stilbenedisulfonate binding site is located at the outer surface of an access channel leading to the transport site.Key words: band 3, anion transport, membrane protein structure, red cell membrane.
ON THE PENETRATING SHOWERS OF COSMIC RAYS
Authors: Voisin André G.
Published: April 2011

Experiments have been carried out at sea level to measure penetration of particles from local showers produced in lead as a function of the angular width of the cone of shower particles. The shower particles are assumed to be mesons and are observed by counter arrangements connected in coincidence and anticoincidence.The results show that the showers containing the more penetrating particles are those of wide angular spread. The multiplicity of penetrating particles per shower is estimated to be at least 3.7, and the curve of the angular distribution shows a maximum corresponding to a shower cone of a half angle of about 15°.
ADAPTATION OF A CHEMICAL BALANCE FOR PRECISION WEIGHING
Authors: Hills A. A.
Published: April 2011

Present manufacturing practices do not tend to provide for the efficient construction of balances of extreme precision. Accordingly, to satisfy the need for a balance capable of determining the difference between weights of 200 gm. nominal value to a precision of one part in 107, a standard chemist's balance was successfully modified without any serious difficulty.
SUR QUELQUES PROBLÈMES POSÉS PAR LES MÉTHODES D'ANALYSE DES GRAPHIQUES PAR LE CALCUL
Authors: Levy par M.
Published: April 2011

not available
GAMMA–NEUTRON REACTIONS IN O16 AND N14
Authors: Haslam R. N. H. , Johns H. E. , Horsley R. J.
Published: April 2011

The cross sections for the reactions O16(γ, n)O15 and N14(γ, n)N13 have been determined by measurement of the induced positron activities. The oxygen cross-section curve has a slowly increasing initial portion after which it rises rapidly to a maximum peak cross section of 11.4 millibarns at 24.0 Mev. The nitrogen cross-section curve has an initial peak at about 13 Mev. Above 17 Mev., this curve increases sharply to a maximum value of 2.84 millibarns at 24 Mev. In order to explain the shape of the nitrogen curve, a relative total neutron yield curve has been determined from 12 to 20 Mev. by detecting the emitted neutrons with a rhodium foil. This neutron yield curve has the same shape as the nitrogen saturated specific activity curve. The anomalous shapes of the nitrogen and oxygen cross-section curves are explained in terms of the variation of gamma-ray absorption with energy.
SURFACE LOSSES IN ELECTROMAGNETIC CAVITY RESONATORS
Authors: Paghis I.
Published: April 2011

The effective skin resistance of brass has been determined at microwave frequencies, by means of Q measurements. Refinements have allowed the Q measurements to be made with an accuracy of the order of 0.3% over a wide frequency range. The measured values are in essential agreement with theoretical prediction, provided that surface treatment is confined to slow hand polishing. This agreement holds for relaxation calculations on re-entrant type resonators, as well as for rigorously soluble resonators. An attempt has been made to correlate the surface roughness of a resonator with the effective skin resistance. The results obtained are in agreement with theoretical work. The effect of surface scratches is small when compared with the effect of a distortion in the crystal lattice at the surface of the brass, due to surface work. The perturbation of the field distribution of the normal modes by wall losses is usually assumed to be negligible. A calculation by the relaxation method shows that, for the best conductors at room temperatures, the perturbation of the normal modes may become serious at millimeter wave lengths.
SYMMETRICALLY PLACED INDUCTIVE POSTS IN RECTANGULAR WAVE GUIDE
Authors: Gruenberg H.
Published: April 2011

A theoretical expression is derived for the susceptance of two symmetrically placed inductive posts in rectangular wave guide. Universal curves are drawn up that are valid for all rectangular guides in their normal operating range, for different post diameters and offsets. Reasonable agreement has been obtained with experiments at 10.7, 4.74, and 3.20 cm. wave lengths.
A STATISTICAL ANALYSIS OF GRAIN COUNTING IN PHOTOGRAPHIC EMULSIONS
Authors: Happ W. W. , Hull T. E. , Morrish A. H.
Published: April 2011

Fluctuations in the grain density of tracks of charged particles passing through photographic emulsions are examined in terms of the physical properties of grains and the type of counting convention used. A mathematical model, for one counting convention which takes into account both the frequency distribution of the grains and the frequency distribution of their lengths, yields numerical results in good agreement with experimental data. Other statistical problems of interest in grain counting are discussed.
SPECTRUM OF THE AlC MOLECULE
Authors: Zeeman P. B.
Published: April 2011

An extensive system of bands in the visible and near infrared regions of the spectrum has been observed in emission when aluminum is present in a King Furnace. These bands have been attributed to the AlC molecule. No metallic carbide spectrum has been described before. A vibrational analysis of the bands has been made. The values ωe′ = 278.795 and ωe″ = 350.011 kaysers were obtained.
THE RADIOACTIVE ISOTOPES Al24, P28, Cl32
Authors: Breckon S. W. , Henrikson A. , Foster J. S. , Martin W. M.
Published: April 2011

The positron emitters P28 (0.29 ± 01 sec.) and Cl32 (0.32 ± 01 sec.) have been discovered in (p, n) reactions with thresholds at 15.4 ± 0.6 Mev. and 14.5 ± 0.6 Mev. respectively. Identification is realized through threshold and transition energies as well as through the complex γ-ray spectra identified in part with the known levels of the daughters Si28 and S32.The new nuclei represent an extension to the series A = 4k, Z = 2k + 1, whose initial members, B8, N12, Na20, are delayed α-emitters, while the recently reported Al24 is known to emit delayed alphas or protons.Under re-examination of Al24, a half-life of 2.0 ± 1 sec. is obtained for γ-ray activity which identifies the stable daughter Mg24.The results are in substantial agreement with the recent work of Glass, Jensen, and Richardson. Delayed α-particles are not observed with the new isotopes.
AN ELECTRONIC RATCHET
Authors: Moody H. J. , Crawford G. J. B.
Published: April 2011

An instrument is described which produces two positive voltage spikes, whose time separation is automatically and systematically increased for each initiating trigger.
CROSS SECTION FOR THE REACTION Al27(γ, n)Al26
Authors: Haslam R. N. H. , Roberts W. N. , Robb D. S.
Published: April 2011

The cross section for the reaction Al27(γ, n)Al26 has been remeasured by the determination of Al26 activity. The results are in agreement with an earlier value obtained by the activity method, but differ from the result obtained by neutron detection. The discrepancy is thought to be due to complexity in the Al26 decay scheme. The reaction threshold is measured as 13.4 ± 0.2 Mev., the maximum energy of positrons from Al26 is 3.2 ± 0.1 Mev., and the half-life is determined as 6.5 ± 0.1 sec.
DIFFRACTION OF 3.2 CM. ELECTROMAGNETIC WAVES BY CYLINDRICAL OBJECTS
Authors: McLay A. B. , Wiles S. T.
Published: April 2011

Diffraction patterns of a brass tube and a hard rubber rod, each a cylinder of 1 in. diameter, in a nearly plane beam of square-wave modulated 3 cm. waves with electric vector parallel to the cylinder axis, have been measured in several planes transverse to the incident beam direction. Experimental results for the conducting cylinder agree closely with calculations based on scalar diffraction theory. Patterns of the dielectric rod show a pronounced central peak immediately behind the rod and other intensity effects differing from the conducting cylinder patterns, particularly in the vicinity of the shadow.
DEAD-TIME LOSSES IN MULTICHANNEL COINCIDENCE SYSTEMS
Authors: Kirkaldy J. S.
Published: April 2011

Correction formulae for the counting losses due to dead-times in multichannel coincidence systems are derived for conditions of significant interchannel correlation and for both continuous and pulsed sources of counts. The dead-times are assumed to be either "extending" (following all counts) or "nonextending" (following only recorded counts). The corrections for the effects of a finite coincidence resolving-time are also evaluated. The approximations used are shown to be valid when the fractional losses are less than 40%, by comparison with the results of a previous experimental paper. The corrections are most likely to be required in the case where the source is intermittent, as from a pulsed accelerator, so that the instantaneous counting rates are very high during the pulse, and where the coincidence rate is of the same magnitude as the non-coincident rates, as in a well-shielded coincidence telescope.
ON THE ANALYSIS OF EXPERIMENTS INVOLVING THE KINETICS OF PILES WITH REFLECTORS
Authors: Rumsey V. H.
Published: April 2011

The theory of pile kinetics is used to analyze measurements of the mean lifetime and migration length of neutrons. The purpose is to show what effects need to be taken into account in the analysis of pile experiments rather than to give a precise experimental verification of the theory. It is shown that the bare-pile one-group model is not adequate. A two-group model which takes into account the presence of the reflector is used to obtain a more accurate analysis. The orders of magnitude are illustrated by deriving formulas for a specific pile—the Chalk River ZEEP. It is found that the presence of the reflector results in an increase of the mean lifetime T of about 20%. Increasing the multiplication constant k∞ by a given amount produces a bigger value of effective multiplication constant ke for the pile with a reflector than without, but owing to the larger value of T, the pile with reflector diverges more slowly than the bare pile. The bare-pile model overestimates by about 10% the change in k∞ required to re-establish stability after a given change in ke. The migration length is overestimated by about 25%. The more elaborate theory agrees well with various measured values, but this is partly fortuitous because the structure of the ZEEP is rather complex and is not adequately represented in the theory.
AN EXPERIMENTAL STUDY OF BAND INTENSITIES IN THE FIRST POSITIVE SYSTEM OF N2: II. THE TRANSITION MOMENT
Authors: Turner R. G. , Nicholls R. W.
Published: April 2011

Experimental band intensities of the first positive system (B3Πg → A3Σu) of nitrogen are used together with theoretical transition probabilities to determine the dependence of the electronic transition moment on the internuclear separation. Over the range 1.17 < r < 1.59 Å of internuclear separation, this dependence may be represented by Re(r) = const. × exp (−3.02 r).
DESCRIPTION OF A COMPOSITE PARTICLE IN TERMS OF A FUNCTIONAL POTENTIAL WELL
Authors: Finkelstein R. , Kaus P. , Gasiorowicz S. G.
Published: April 2011

A covariant two-particle wave equation of the following form is investigated:[Formula: see text]where Dk is the Dirac operator (γμpμ – im)k and F(ψ) is a functional "potential well", Ψαa. is interpreted as a probability amplitude and transforms as a spinor on both indices. ψ is the internal wave function depending only on the relative coordinates. This equation provides a covariant model which exhibits nonlocal interactions and can be studied by relatively simple methods. The investigation is primarily methodological. The physical model is similar to the Fermi–Yang pion and like it, is qualitative and not based on fundamental theory.
ON THE RELATION BETWEEN QUANTUM HYDRODYNAMICS AND CONVENTIONAL QUANTUM FIELD THEORY
Authors: Kaempffer F. A.
Published: April 2011

The conditions are examined under which the procedure of quantum hydrodynamics would be a consequence of the conventional quantization procedure, and vice versa. Using the classical nonrelativistic theory of a charged medium as an example, it is shown that the commutation rules of the two procedures differ by a factor 2, if in accordance with an idea by Geilikman the wave function of the classical theory is expanded as ψ = ψ0 + ψ1, with ψ0 a constant and [Formula: see text], and if terms of higher than second order in ψ1 are neglected in the hydrodynamical description of the theory.
COSMIC RAY PHENOMENA AT MINIMUM IONIZATION IN A NEW NUCLEAR EMULSION HAVING A FINE GRAIN, MADE IN THE LABORATORY
Authors: Demers Pierre
Published: April 2011

The preparation of a silver bromide emulsion in the form of baseless sheets and their use in thick homogeneous stacks are described. In these sheets, a suitable development brings out minimum ionization tracks with a grain diameter 0.1 to 0.2 μ, and a linear grain density of 15 per 100 μ. The sequence of observations which led to the positive identification of minimum tracks is discussed. Short recoils and delta rays are visible, and excellent discrimination is available at all ionizing powers. The influence of grain size on fog is analyzed.Several cosmic ray phenomena containing minimum tracks are presented: single tracks, hard showers, πμe events, and an electron pair. Distortion is very small, and it is shown that the small grain size renders feasible better scattering measurements on higher energy particles. With this emulsion, nearly every possible measurement should become feasible with greater accuracy.
IMAGE INTERFERENCE IN CALM, NEAR-ISOTHERMAL WATER
Authors: Sanders Frederick H.
Published: April 2011

Some experiments are described in which strong image interference of underwater sound has been observed and measured. These effects occur frequently in coastal British Columbia waters, where calm surface conditions are common, and have been observed at frequencies close to 20 kc./sec. The observations are compared with theoretical predictions for small sound velocity gradients and reasonably good agreement obtained.
THE ANGULAR DISTRIBUTION OF THE Li7(t, α)He6 REACTIONS AT 240 KEV. TRITON ENERGY
Authors: Almqvist E. , Pepper T. P. , Lorrain P.
Published: April 2011

The angular distributions of the Li7(t, α)He6 reactions have been measured between 41° and 139° to the beam in the laboratory system. The distribution of the 5.95 Mev. α-particles associated with the formation of ground state He6 is of the form [Formula: see text] in the center of mass system. The 4.95 Mev. α-particles associated with the formation of the first excited state of He6 are distributed isotropically within ±8%. These results are consistent with the expectation that the ground state of He6 has spin 0 and the first excited state spin 2 and suggest that the compound state, Be10, has J = 2.
STATISTICAL STUDIES OF POLAR RADIO BLACKOUTS
Authors: Cox J. W. , Davies Kenneth
Published: April 2011

A statistical study of high frequency radio blackouts in Canada is made from records taken at several ionosphere sounding stations. Both vertical incidence and communication data are examined to determine the geographical, seasonal, and diurnal distributions of the frequency of occurrence of blackout. It is found that blackouts are most abundant in the morning and that the time of maximum occurrence increases with increasing latitude.
IONIZATION PROBABILITY CURVES USING AN ELECTRON SELECTOR: RESULTS ON N2+, N+, Xe++
Authors: Clarke E. M.
Published: April 2011

An apparatus consisting of an electron energy selector built into a mass spectrometer is described. With it, initial ionization yield curves may be obtained. The interpretation of these curves is discussed, and the following new measurements reported:[Formula: see text]
SURFACE TENSION OF He3
Authors: LoveJoy D. R.
Published: April 2011

The surface tension of He3 has been measured by a capillary rise method between 1.08° and 2.32°K. A decrease of more than 50% was observed in this range and this supports the ideas on which Atkins' theory of the surface tension of liquid helium is based. On the basis of this theory the surface tension has been extrapolated to 0°K., where it has the value 0.154 ± 0.005 erg cm.−2. Above 2.3°K. it was extrapolated linearly to zero at the critical temperature. The Eötvös constant was calculated to be about 0.8.
DIURNAL VARIATIONS IN THE NUMBER OF SHOWER METEORS DETECTED BY THE FORWARD-SCATTERING OF RADIO WAVES: PART II. EXPERIMENT
Authors: Forsyth P. A. , Hines C. O. , Vogan E. L.
Published: April 2011

The theory developed in Part I is applied to derive the expected diurnal variations of the meteor signal rate for four showers as observed by means of a particular forward-scatter transmission path (Cedar Rapids – Ottawa). These results are then compared with the experimental signal rates. The good agreement obtained indicates that the approximations inherent in the theory are sufficiently accurate for practical purposes. The results also indicate that very few meteors, if any, are observed under conditions which do not satisfy the requirements for specular reflection.
ATTENUATION OF 5 MC. SOUND IN ALUMINUM AT LOW TEMPERATURES
Authors: Hutchison T. S. , Filmer A. J.
Published: April 2011

The attenuation of sound at a frequency of 5 megacycles has been found to reach a maximum in aluminum at 155 °K. Combination of this result with the work of Bordoni, who obtained a maximum at 40 kilocycles and 100 °K., gives an activation energy in agreement with the value calculated by Mason for a dislocation relaxation process. The maximum is greatly increased by plastic deformation. The velocities of sound for annealed and cold-worked aluminum show a maximum difference about 155 °K., again indicating a dislocation mechanism. The maxima are superimposed on a background attenuation mostly caused by scatter at grain boundaries and diffraction.
(γ, p + α) REACTIONS PRODUCED IN PHOTOGRAPHIC EMULSIONS
Authors: Livesey D. L.
Published: April 2011

Ilford C.2 plates were exposed to bremsstrahlung of maximum energy 70 Mev. from the electron synchrotron at Queen's University, and 82 stars produced in the emulsion have been attributed to the reaction:[Formula: see text]The excitation function of the reaction shows a sharp drop near 40 Mev. and the integrated cross-section up to this limit has been estimated. In addition 23 stars have been identified as being due to the reaction:[Formula: see text]In both reactions the most probable mode of disintegration is by the initial emission of an alpha-particle. The range measurements in the carbon stars have been used to derive an accurate range–energy relation for lithium ions in nuclear emulsion.
THE ELECTRICAL CONDUCTIVITY OF CHLOROBENZENE
Authors: Hart John , Mungall A. G.
Published: April 2011

Measurements of the conductivity of chlorobenzene in evacuated cells of identical geometry but with different electrode metals have shown that the conductivity measured is dependent on the electrode metal employed. The degree of dependence is more marked and the conductivities are one or two orders of magnitude larger in the presence of air. Preliminary measurements of small discharge currents in a cell with monel metal electrodes are also described.
DIFFRACTION OF 3.2 CM. ELECTROMAGNETIC WAVES BY DIELECTRIC RODS: I. LUCITE AND TENITE 1 IN. DIAMETER CYLINDERS
Authors: Subbarao M. K. , McLay A. B.
Published: April 2011

Diffraction patterns of lucite and tenite cylindrical rods of approximately one inch diameter, in a nearly plane beam of square-wave modulated 3.2 cm. waves with electric vector parallel to the cylinder axis, have been measured in several planes transverse to the incident beam direction. Patterns are compared with theoretical ones (Froese and Wait 1954) and with ones obtained earlier, under similar experimental conditions, for brass and hard rubber cylinders (Wiles and McLay 1954). Some general marked trends in the patterns of the four rods, comprising a conductor, two nearly lossless dielectrics with different dielectric constants, and a lossier dielectric, are related to the effects of transmission and/or surface reflection expected from geometrical optics considerations.
A QUANTUM MECHANICAL DESCRIPTION OF COLLECTIVE MOTIONS
Authors: Skinner R.
Published: April 2011

A rigorous and general formalism is presented for the quantum mechanical description of the collective motions of a system containing a finite number of particles. The dynamical equations are expressed in terms of collective and "internal" coordinates. The internal coordinates are symmetrical in the particles, and correspond to the laboratory coordinates with the collective motions subtracted off. The formalism is applied to center of mass motion.
LATITUDE EFFECT OF THE COSMIC RAY NUCLEON AND MESON COMPONENTS AT SEA LEVEL FROM THE ARCTIC TO THE ANTARCTIC
Authors: Rose D. C. , Fenton K. B. , Katzman J. , Simpson J. A.
Published: April 2011

Results are presented of cosmic ray measurements taken at sea level during 1954–55 from the Arctic to the Antarctic. The equipment consisted of a neutron monitor and a meson telescope. Latitude effects of 1.77 for the nucleonic component and 1.15 for the meson component were measured. The longitude effect at the equator was much less than expected on the basis of the geomagnetic eccentric dipole and the longitude effect at intermediate northern latitudes shows that the longitude of the effective eccentric dipole is considerably west of that of the geomagnetic eccentric dipole. In a previous paper by the same authors, the positions of the equatorial minima were combined with other published cosmic ray measurements to calculate a new cosmic ray geomagnetic equator. In this paper new coordinates are derived on the assumption that these equatorial coordinates apply to a new eccentric dipole, and, therefore, that the equatorial coordinates may be extended to high latitudes. When the complete results are plotted on these coordinates, it is found that an eccentric dipole representation of the earth's magnetic field is inconsistent with the combined observations at all latitudes.
THE SPATIAL DISTRIBUTION OF SIGNAL SOURCES IN METEORIC FORWARD-SCATTERING
Authors: Hines C. O. , Pugh R. E.
Published: April 2011

The spatial distribution of observable meteor trails is determined, with the aid of the 'cylindrical approximation' appropriate to forward-scattering observations. Contour charts of the distribution are presented, and found to compare favorably with those obtained from a more exact analysis, presented in a companion paper. Typical effects of the signal durations are also examined. The whole is compared with an earlier development by Eshleman and Manning (1954), which treats closely related aspects of meteoric forward-scattering.
THE LUMINOUS MANTLE OF FUEL-RICH OXYACETYLENE FLAMES: II. FREE RADICAL AND CONTINUUM INTENSITIES, AND THEIR INFLUENCE ON C3 EMISSIONS
Authors: Marr G. V.
Published: April 2011

The spectroscopic emissions from the luminous mantle of the oxyacetylene flame have been examined over a range of burning mixtures from 2.3 to 4.2 times stoichiometric. Plots of the band-head intensities for the radicals C2, C3, CH, and CN for different burning mixtures and for vertical traverses through the flame are reported. From a study of the variation of the background continuum from 3000 Å to 5200 Å with burning mixtures, the over-all continuum may be considered to consist of (a) a black-body carbon particle continuum having an energy distribution corresponding to a temperature of 2900 ± 200° K., (b) a continuum associated with the C3 radical emissions extending from 3500 Å to 4600 Å with a maximum at 4000 Å, and (c) an ultraviolet continuum extending from below 3000 Å to 5000 Å which appears similar to the carbon-monoxide flame continuum. Within the limits of experimental error the variation of the C3 bands and their associated continuum are identical. Possible reaction mechanisms for the production of the C3 emissions are considered and they probably may be accounted for by the reaction scheme[Formula: see text]
NEUTRON CAPTURE GAMMA RAYS FROM FLUORINE, MAGNESIUM, GALLIUM, BROMINE, AND HAFNIUM
Authors: Campion P. J. , Bartholomew G. A.
Published: April 2011

The neutron capture γ-ray spectra of fluorine, magnesium, gallium, bromine, and hafnium have been studied in the energy range above 3 Mev. In fluorine four γ-rays and in magnesium 12 γ-rays have been detected in addition to those previously observed. Most of these new radiations can be assigned to the known level schemes of the product nuclei. The spectrum obtained for each of the other elements is complex with only a few of the high energy γ-rays resolved, and in each case the γ-ray of highest energy is very weak and difficult to distinguish from the background. The most energetic gallium γ-ray at 7.73 ± 0.02 Mev. may be emitted in the direct ground state transition in Ga70 while the 7.879 ± 0.013 Mev. γ-ray from bromine probably corresponds to the ground state transition in Br80. In hafnium none of the observed γ-rays can be identified with a ground state transition in any of the isotopes.
AN ELECTRICAL RECORDING MAGNETOMETER
Authors: Serson P. H.
Published: April 2011

An instrument for recording at a fixed station variations in three orthogonal components of the earth's magnetic field is described. The sensitive head, containing detectors of the saturated transformer type, can be operated out of doors at the end of a long cable. A strip-chart recording meter provides a visible record of the three d-c. output signals (1 volt = 100 gammas). Calibrated baseline controls permit biasing of the magnetic detectors for any location in Canada. Tests on 10 instruments indicate a noise level of 3 gammas and a maximum drift of 10 gammas in 10 hours.
POISSON BRACKETS IN FIELD THEORY
Authors: Freistadt Hans
Published: April 2011

Poisson brackets for covariant field theory are defined in such a way as to demonstrate the close connection and ready transition between the classical brackets and the corresponding commutators of quantum theory. The approach of Good is followed in general; but the questions of tensor algebra are handled differently, requiring the introduction of a family of space-like surfaces and their normals. As an illustration, the free Klein-Gordon and Dirac fields are worked out.
THE CUMULATIVE FISSION YIELDS OF 21 HEAVY MASS NUCLIDES PRODUCED IN THE THERMAL FISSION OF Pu239
Authors: Fickel H. R. , Tomlinson R. H.
Published: April 2011

Mass spectrometric analysis of cesium, barium, cerium, neodymium, and samarium produced in the thermal fission of Pu239 has made possible the determination of the cumulative yields of 17 mass chains. With previously published mass spectrometric yields of four xenon isotopes normalized to the present data a total of 21 cumulative yields are reported.
THE MAGNETIC SUSCEPTIBILITIES OF SOME DIAMAGNETIC ALLOYS: THE PRIMARY SOLID SOLUTIONS OF CADMIUM, INDIUM, TIN, AND ANTIMONY IN COPPER AND IN SILVER; ZINC, GALLIUM, GERMANIUM, AND ARSENIC IN SILVER; COPPER IN SILVER AND SILVER IN COPPER
Authors: Henry W. G. , Rogers J. L.
Published: April 2011

The results of the measurements of the variation with concentration of the magnetic susceptibility in the solid solutions of the following systems are presented: copper with silver, cadmium, indium, tin, and antimony as solutes; silver with copper, zinc, gallium, germanium, arsenic, cadmium, indium, tin, and antimony as solutes. The density of states for silver is calculated by using the approximation to nearly free electrons. It is found that the density of states is decreasing at an electron to atom ratio of 1.0. It is further found that the method used in an earlier paper to discuss the magnetic properties of the α-solid solutions formed with copper by zinc, gallium, germanium, and arsenic is applicable to the monovalent–polyvalent systems of the present paper. It is concluded from the magnetic measurements that the Fermi surface touches the (III) Brillouin zone face in both silver and copper and that the rate of decrease of the density of states with electron to atom ratio is given approximately by the approximation to nearly free electrons. The solid solutions in the silver–copper system are anomalous.
AN ILLUSTRATION OF A TYPE OF TRIPLE CORRELATION MEASUREMENT WHICH CAN BE EASILY INTERPRETED
Authors: Litherland A. E. , McCallum G. J.
Published: April 2011

The Mg26(He4, nγ)Si29 reaction has been used to illustrate the simplifications introduced in the interpretation of triple angular correlations by choosing a target and bombarding particles of zero spin and by observing the emitted particles, in this case neutrons, in a counter fixed at 0° to the beam. The angular correlations of the gamma rays with respect to the incident beam then depend only upon the properties of the final states in the residual nucleus. The angular correlation of the electric quadrupole 2.03-Mev gamma ray is predicted uniquely by theory and this prediction has been verified experimentally. The angular correlations of the 1.28-Mev and 2.43-Mev gamma rays have yielded for the E2/M1 amplitude mixing ratios +0.25 ± 0.05 or −3.4 ± 0.5 and −0.26 ± 0.08 or −1.10 ± 0.16 respectively. In addition, the experiment provides an illustration of the value of the recently discovered technique of neutron – gamma-ray discrimination in an organic scintillator.
DIFFUSION PHENOMENA AND ISOTOPE EFFECTS IN THE EXTRACTION OF FISSION-PRODUCT XENON AND KRYPTON FROM IRRADIATED U3O8
Authors: Kennett T. J. , Thode H. G.
Published: April 2011

An investigation of the diffusion of fission-product xenon and krypton from irradiated U3O8 powder as a function of temperature has revealed isotopic fractionation and also a double-valued activation energy. The apparent fission yields of Xe131 and Xe132 show abnormal enrichments of up to a factor of 10. These enrichments appear to be related to the precursor half-lives of xenon. When isotopic fractionation exists, the diffusion results exhibit an extremely low energy of activation.
NUMERICAL VALUES OF SOME INTEGRALS OCCURRING IN THE THEORY OF HEAT CONDUCTION WITHIN CYLINDRICALLY SYMMETRIC REGIONS
Authors: Benson G. C. , Benjamin L.
Published: April 2011

Values of three functions E(h,α,τ,), F(h,α,τ), and G(h,α,τ,), denned inequations (1), (2), and (7), have been calculated numerically for h = 600–15,000, α = 3–15, and τ = 150–1950. These results should be of use in certain problems of heat conduction in regions with cylindrical symmetry.
HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: XIV. ROTATIONAL SPECTRA OF C2H6, C2D6, C2H3D3 AND STRUCTURE OF THE ETHANE MOLECULE
Authors: Stoicheff B. P.
Published: April 2011

An analysis of the rotational Raman spectra of three isotopic species of ethane has given the following values for the rotational constants:[Formula: see text]From these values alone it is found that r0(C—C) = 1.5376 ± 0.003 Å, and when these are combined with, already available values of Ia (the moment of inertia about the symmetric top axis), the CH3 parameters are determined to be r0(C—H) = 1.106 ± 0.006 Å and [Formula: see text].
New emission band systems of the NH+ molecule
Authors: Colin R. , Douglas A. E.
Published: April 2011

Two new band systems of the NH+ molecule have been photographed at high dispersion and analyzed. One system consists of a single band at 4348.5 Å which arises from a 2Δ–2Π transition and the second consists of three bands of a 2Σ−–2Π transition with the strongest (0–0) band lying at 4628.9 Å. A number of the vibrational and rotational constants of these states have been determined. From a study of the isotopic species 14NH+, 15NH+, and 14ND, it has been established that the ground state of NH+ is the 2Π state and that a 4Σ− state lies 354 cm−1 higher. The spectrum has allowed us to determine the wavelengths at which cometary spectra and interstellar absorption lines of NH+ are expected to fall and to predict that the transition between the two lowest levels, which may be of interest to radio astronomy, occurs at 13 500 mc/s.
The electron spin resonance of Mn2+ in tremolite
Authors: Manoogian A.
Published: April 2011

The electron spin resonance of Mn2+ ion impurities in natural crystals of tremolite, 2(H2Ca2Mg5-(SiO3)8), was studied in the 9.2 GHz microwave frequency range, and at room temperature. The work was done on two crystals of tremolite containing different concentrations of Mn2+. In each case only one magnetic complex of Mn2+ was found. The resonance lines are characterized by a strong angular dependence of the line intensities, and this is coupled with the appearance of many forbidden lines of Mn2+. The resonance lines of the allowed transitions were fitted to a spin Hamiltonian of orthorhombic symmetry.
Excitation of a conducting cylinder by an axial electric dipole
Authors: Shafai L.
Published: April 2011

The electromagnetic field of an axial electric dipole near a perfectly conducting cylinder of circular cross section is expressed in terms of an infinite integral. For the magnetic field on the surface of the cylinder, the integral is evaluated analytically for cylinders of small and large radii and numerically for cylinders of moderate radii.
The application of an automated data acquisition system to T1 measurements in compressed hydrogen gas
Authors: Tward E. , Armstrong R. L.
Published: April 2011

An automated pulsed magnetic resonance spectrometer utilizing sampling and averaging techniques is described. This system is used to make T1 measurements in normal hydrogen gas at 77.5, 195, and 298 °K in the pressure range 1 to 2400 atm. The results in the dilute gas, extreme narrowing region are discussed in terms of the possibility of obtaining T1/ρ values accurate to 1%. The dense gas results show a density dependence similar to that of earlier measurements made in the compressed liquid. This density dependence is not understandable in terms of the liquid model of the Bloom–Oppenheim theory.
The effect of thermal history on the crystallization behavior of selenium
Authors: Janjua M. B. I. , Toguri J. M. , Dutrizac J. E.
Published: April 2011

The effect of thermal history on the crystallization behavior of selenium has been studied by both dilatometric and microscopic methods. The spherulitic growth rate was found to be insensitive to thermal pretreatment while the total crystallization rate depended strongly on the thermal history of the material. It was concluded that high-purity selenium crystallizes by heterogeneous nucleation.
The Herzberg II system of O2 in emission in the oxygen–argon afterglow
Authors: Degen Vladimir
Published: April 2011

Several hitherto unidentified very faint emission bands were observed in the oxygen–argon afterglow under a moderately high dispersion. Two of these bands at 4491 and 4791 Å were identified as the (0–7) and (0–8) bands, respectively, of the Herzberg II [Formula: see text] forbidden system of O2, where the previous vibrational assignment of the upper state has been raised by five units. Their rotational structure was analyzed and the new molecular constants are given. The rest of the bands, some of which also occur in the nightglow, belong to some other band system. They were not analyzed because of insufficient resolution.
Field ionization in semi-insulating thin films
Authors: Reed L. D. , Brodie D. E.
Published: April 2011

Evidence is presented to support the possibility of direct field ionization, at 4 °K, of shallow trapping levels in vacuum-deposited films of such materials as CdSe and CdTe. A method proposed by Haering (1959) is used and, in the case of relatively well-defined trapping levels, quantitative agreement is found between the results and the predictions based on Haering's theory.While many of the several hundred samples prepared showed a continuous distribution of trapping levels, it was possible to fabricate samples in such a way that one obtained results indicating a relatively narrow distribution of levels. Furthermore, on the basis of the above theory, it was possible to obtain estimates of the depths of the energy levels involved.Some of the advantages and disadvantages of the method are outlined and, in particular, the effects likely to compete with field ionization are considered.