bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidation Behavior of a Ti3AlC2/TiB2 Composite at 1000°−1400°C in Air
Authors: Li Meishuan , Li Chao , Li Jingjing , Zhou Yanchun
Published: December 2009

The oxidation behaviors of a Ti3AlC2/20(vol%)TiB2 composite, synthesized by means of in situ reactions of Ti, Al, graphite, and B4C powder mixtures under hot pressing, have been investigated at 1000°–1400°C in air. The Ti3AlC2/20TiB2 composite followed the logarithmic oxidation law, and had a lower oxidation rate than the matrix Ti3AlC2. During the oxidation at 1000°–1400°C, a continuous Al2O3 formed on the composite, meanwhile other different oxides formed on the top surface of the Al2O3 layer, depending on the oxidation temperature: discontinuous α‐TiO2 at below 1200°C, mixture of Al2TiO5 and TiO2 at 1300°C, and continuous Al2TiO5 at 1400°C. The selective oxidation of Al occurred at the oxide/substrate interface through inward diffusion of oxygen, and TiO2 overgrew the Al2O3 layer to form coarse grains through outward diffusion of titanium ions. When the temperature was above 1280°C, Al2TiO5 appeared due to a eutectic reaction between TiO2 and Al2O3. The incorporation of TiB2 promoted the generation of great numbers of voids at the Al2O3/substrate interface and in the Al2O3 inner layer, which is proposed as being the main reason for the Ti3AlC2/20TiB2 composite to follow a logarithmic oxidation law.
Sodium Fluoride Solubility and Crystallization in Photo‐Thermo‐Refractive Glass
Authors: Fokin Vladimir M. , Souza Guilherme P. , Zanotto Edgar D. , Lumeau Julien , Glebova Larissa , Glebov Leonid B.
Published: December 2009

Photo‐thermo‐refractive (PTR) glass undergoes a refractive index change after UV exposure followed by heat treatment for nanocrystallization of NaF, allowing phase holograms to be permanently recorded in the glass. PTR glass was invented 60 years ago, and optical elements based on PTR glass have been produced for the past decade, but its detailed crystallization mechanism is largely unknown. Since solubility and composition of the parent glass determine the supersaturation and hence the thermodynamic driving force for crystallization, the present paper was aimed at measuring the solubility of NaF in PTR glass via estimating the equilibrium volume fraction of crystallized NaF as a function of temperature. The temperature above which all NaF originally contained in the parent glass remains dissolved in the melt, and that below which all NaF could crystallize, were also estimated. Redesigning of thermal processing parameters and composition of PTR glass, aiming at the improvement of optical elements based on this glass, can be performed in light of the results achieved.
Quantum Cutting in Tm3+/Yb3+‐Codoped Lanthanum Aluminum Germanate Glasses
Authors: Zhang Qiang , Zhu Bin , Zhuang Yixi , Chen Guorong , Liu Xiaofeng , Zhang Guang , Qiu Jianrong , Chen Danping
Published: December 2009

In the present paper, Tm3+/Yb3+‐codoped lanthanum aluminum germanate glasses are prepared by simply melting and quenching method. Quantum cutting (QC) between Tm3+ and Yb3+ ions in these samples is realized; in the QC process, one blue photon at about 467 nm is cut into two near‐infrared photons at about 1 μm. The maximum energy transfer efficiency and the corresponding QC efficiency can reach as high as 59.9% and 159.9%, respectively.
Influence of MnO2 Doping on the Dielectric and Piezoelectric Properties and the Domain Structure in (K0.5Na0.5)NbO3 Single Crystals
Authors: Lin Dabin , Li Zhenrong , Zhang Shujun , Xu Zhuo , Yao Xi
Published: December 2009

MnO2‐doped (K0.5Na0.5)NbO3 (KNN) single crystals were grown by high‐temperature solution method using K2CO3–Na2CO3 eutectic composition as flux. The effect of the manganese dopant on the dielectric, piezoelectric properties and the domain structure was investigated. The MnO2‐doped KNN crystals were found to exhibit higher piezoelectric coefficient d33 and dielectric permittivity ɛr when compared with pure KNN crystal, being on the order of 270 pC/N and 730, respectively, for manganese‐doped level at 0.5 mol%, with slightly reduced orthorhombic to tetragonal phase transition TO—T, and Curie temperature TC, being on the order of 193° and 416°C, respectively. The domain size of [001]‐oriented KNN–Mn crystal was found to be on the order of 5–13 μm at room temperature, smaller than that of the domain size observed in the pure KNN crystal (20–30 μm). The thermal depoling experiments were performed on the [001]‐poled KNN–Mn crystals, where the partial depolarization was found to occur at temperatures above 200°C, due to the phase transformation.
Ethics in Archaeology and Anthropology: Interrelated or Inherently Different?
Authors: Gongaware Laura , O'Halloran Laura Short
Published: December 2009

Liam Frink is contributing editor of “Ethical Currents,” the AAA Committee on Ethics column in Anthropology News.
NMDA receptors‐dependent plasticity in the phototaxis preference behavior induced by visual deprivation in young and adult flies
Authors: Zhou M. , Lei Z. , Li H. , Yi W. , Zhang Z. , Guo A.
Published: December 2009

Adult mammals have experience‐dependent plasticity in visual system, but it is unclear whether adult insects also have this plasticity after the critical period of visual development. Here, we have established a modified Y‐maze apparatus for investigating experience‐dependent plasticity in Drosophila. Using this setup we demonstrate that flies after the critical period have bidirectional modifications of the phototaxis preference behavior (PPB) induced by visual deprivation and experience: Visual deprivation decreases the preference of flies for visible light, while visual experience exerts the opposite effect. We also found an age‐dependent PPB plasticity induced by visual deprivation. Molecular and cellular studies suggest that the N‐methyl‐ d‐aspartate receptors (NMDARs) mediate ocular dominance plasticity in visual cortex in mammals, but direct behavioral evidence is lacking. Here, we used the genetic approaches to demonstrate that NMDAR1, which is NMDARs subunit in Drosophila, can mediate PPB plasticity in young and adult flies. These findings provide direct behavioral evidence that NMDAR1 mediates PPB plasticity in Drosophila. Our results suggest that mammals and insects have analogous mechanisms for experience‐dependent plasticity and its regulation by NMDAR signaling.
Competition in the Courtroom: When Does Expert Testimony Improve Jurors' Decisions?
Authors: Boudreau Cheryl , McCubbins Mathew D.
Published: December 2009

Many scholars lament the increasing complexity of jury trials and question whether the testimony of competing experts helps unsophisticated jurors to make informed decisions. In this article, we analyze experimentally the effects that the testimony of competing experts has on (1) sophisticated versus unsophisticated subjects' decisions and (2) subjects' decisions on difficult versus easy problems. Our results demonstrate that competing expert testimony, by itself, does not help unsophisticated subjects to behave as though they are sophisticated, nor does it help subjects make comparable decisions on difficult and easy problems. When we impose additional institutions (such as penalties for lying or a threat of verification) on the competing experts, we observe such dramatic improvements in unsophisticated subjects' decisions that the gap between their decisions and those of sophisticated subjects closes. We find similar results when the competing experts exchange reasons for why their statements may be correct. However, additional institutions and the experts' exchange of reasons are less effective at closing the gap between subjects' decisions on difficult versus easy problems.
The Role of Natriuretic Peptides in Patients With Chronic Complex (Mixed or Multiple) Heart Valve Disease
Authors: Bissessor Naylin , Shanahan Luke , Wee Yong Shen , Stewart Ralph , Lowe Boris , Kerr Andrew , Zeng Irene , Jayasinghe Rohan , White Harvey
Published: December 2009

N‐terminal prohormone B‐type natriuretic peptide (NT‐proBNP) is an important biomarker of prognosis in heart failure and single valve disease. There are limited studies of complex valve disease. Patients with complex valve disease adopt a sedentary lifestyle, so symptoms may be difficult to detect. The authors aimed to determine whether NT‐proBNP correlates with the severity of the valve lesion and underlying cardiac function and whether resting NT‐proBNP predicts impaired peak VO2 in patients with complex valve disease. Forty‐five patients with complex moderate to severe stenosis or regurgitation of the heart valves underwent a clinical assessment, echocardiography, resting NT‐proBNP assessment, and formal cardiopulmonary exercise testing. In a multivariate analysis, the log NT‐proBNP (β=−9.3, SE=1.9, P<.0001) and lean body weight (β=0.59, SE=0.22, P=.01) were dominant independent predictors of peak VO2. An NT‐proBNP value of 84 pmol/L had 77% sensitivity and 70% specificity to predict impaired functional capacity, peak VO2 <60% (predicted), area under the curve=0.80. Resting NT‐proBNP was the best predictor of peak VO2 in patients with complex valve disease, while symptoms and ejection fraction are a less reliable guide.

Congest Heart Fail. 2010;16:50–54. © 2009 Wiley Periodicals, Inc.
Formation and Survival of Water Vapor in the Terrestrial Planet–Forming Region
Authors: Bethell Thomas , Bergin Edwin
Published: December 2009

Watery Worlds

Water vapor has been detected in the protoplanetary disks of a variety of stars. Explaining its origin is important because it bears on our understanding of planet formation.
Bethell and Bergin
(p.
1675
) propose that this water originates in photochemistry occurring in the upper layers of the disks. In these regions, the rate at which water is produced exceeds the rate at which water is destroyed by ultraviolet radiation. Water forming in the upper layers of the disks then shields water vapor within the disks' interiors, allowing that vapor to interact with planet-forming materials and possibly be incorporated into young planets.
Stepwise Modification of a Modular Enhancer Underlies Adaptation in a
Drosophila
Population
Authors: Rebeiz Mark , Pool John E. , Kassner Victoria A. , Aquadro Charles F. , Carroll Sean B.
Published: December 2009

Degrees of Darkness

Fruit flies in Africa have a tendency to be darker, the higher the altitude at which they live, because melanization offers a selective advantage. The dark pigmentation seen in some populations of Ugandan
Drosophila melanogaster
is owing to a lack of expression of the ebony gene, and expression results in yellow cuticle.

Rebeiz
et al.

(p.
1663
; see the News story by

Pennisi

) show that mutations in
cis
regulatory elements, rather than in the coding region, are responsible for the dark color. A series of five mutations in a modular enhancer element influences the level of
ebony
expression: Three mutations already existed in fly populations with light cuticle color and a further two, more recently acquired dark-specific substitutions, together have created an allele of large effect, which has been swept to high frequency in this population of flies.
Indirect Punishment and Generosity Toward Strangers
Authors: Ule Aljaž , Schram Arthur , Riedl Arno , Cason Timothy N.
Published: December 2009

Cheaper Cooperation

In the context of public goods games in which optimal benefit is achieved when all participants contribute, bad behavior cannot always be deterred by direct punishment, and has the added disadvantage that the punisher may suffer a cost. Alternatively, instead of punishment, rewarding those who contribute can be effective in encouraging and maintaining widespread cooperation, with the added plus that group benefits are not diminished by the costs of punishment. But

Ule
et al.

(p.
1701
) discovered experimentally that if someone is treated depending on how they have behaved in previous interactions, retaining the option to occasionally apply punishment shifts the payouts to favor cooperators more than defectors.
Spatial Organization of Hominin Activities at Gesher Benot Ya’aqov, Israel
Authors: Alperson-Afil Nira , Sharon Gonen , Kislev Mordechai , Melamed Yoel , Zohar Irit , Ashkenazi Shosh , Rabinovich Rivka , Biton Rebecca , Werker Ella , Hartman Gideon , Feibel Craig , Goren-Inbar Naama
Published: December 2009

Home Is Where the Hearth Is

One aspect of human intelligence is the ability to organize our living and working spaces. It was generally thought that this capability arose with modern humans in the past 100,000 years or so. However,

Alperson-Afil
et al.

(p.
1677
) found evidence of domestic organization 800,000 years ago at a Pleistocene hominin campsite in the Jordan Valley. Around patches of burnt debris, the remains of a wide range of plant and animal foodstuffs were found, including fruits and seeds, as well as remnants of turtles, elephants, and small rodents. Specific types of stone tools appear to have been made around the hearths, where there was also evidence of nut roasting and consumption of crabs and fish. In a more distant area there were signs of intensive flint knapping and food chopping.
Sexual Selection and Darwin's Mystery of Mysteries
Authors: Mank Judith E.
Published: December 2009

Natural selection and mating preference for traits that signal adaptation to the local environment work together in a model of speciation.
The Breakthroughs of 2009
Authors: Alberts Bruce
Published: December 2009

Every December, the editors of
Science
face the challenge of reviewing what Science has accomplished around the world in the past 12 months, so as to select our “breakthroughs of the year.” The task is an invigorating one, providing a powerful reminder of both the enormous scope and the continual advance of science. For this year's selections, the range is staggering. From the discovery of pulsars created by neutron stars that are many thousands of light-years distant, to the production of a new single-atom–thick material such as graphene, the same natural laws and logic have generated new understandings over a more than 10
30
-fold difference in scale. And there is usually special excitement when an advance directly concerns humans, as in the discovery of an ancient ancestor or a successful application of gene therapy to cure disease.
Peril in the Pamirs
Authors: Stone Richard
Published: December 2009

Concerns about the risk of a calamitous flood from a mountain lake in Central Asia have scientists racing to improve evacuation plans and find an engineering fix.
Francisella tularensis
T-Cell Antigen Identification Using Humanized HLA-DR4 Transgenic Mice
Authors: Yu Jieh-Juen , Goluguri TataReddy , Guentzel M. Neal , Chambers James P. , Murthy Ashlesh K. , Klose Karl E. , Forsthuber Thomas G. , Arulanandam Bernard P.
Published: December 2009

There is no licensed vaccine against the intracellular pathogen
Francisella tularensis
. The use of conventional mouse strains to screen protective vaccine antigens may be problematic, given the differences in the major histocompatibility complex (MHC) binding properties between murine and human antigen-presenting cells. We used engineered humanized mice that lack endogenous MHC class II alleles but that express a human HLA allele (HLA-DR4 transgenic [tg] mice) to identify potential subunit vaccine candidates. Specifically, we applied a biochemical and immunological screening approach with bioinformatics to select putative
F. tularensis
subsp.
novicida
T-cell-reactive antigens using humanized HLA-DR4 tg mice. Cell wall- and membrane-associated proteins were extracted with Triton X-114 detergent and were separated by fractionation with a Rotofor apparatus and whole-gel elution. A series of proteins were identified from fractions that stimulated antigen-specific gamma interferon (IFN-γ) production, and these were further downselected by the use of bioinformatics and HLA-DR4 binding algorithms. We further examined the validity of this combinatorial approach with one of the identified proteins, a 19-kDa
Francisella tularensis
outer membrane protein (designated
Francisella
outer membrane protein B [FopB]; FTN_0119). FopB was shown to be a T-cell antigen by a specific IFN-γ recall assay with purified CD4
+
T cells from
F. tularensis
subsp.
novicida
Δ
iglC
-primed HLA-DR4 tg mice and cells of a human B-cell line expressing HLA-DR4 (DRB1*0401) functioning as antigen-presenting cells. Intranasal immunization of HLA-DR4 tg mice with the single antigen FopB conferred significant protection against lethal pulmonary challenge with an
F. tularensis
subsp.
holarctica
live vaccine strain. These results demonstrate the value of combining functional biochemical and immunological screening with humanized HLA-DR4 tg mice to map HLA-DR4-restricted
Francisella
CD4
+
T-cell epitopes.
Targeted Delivery of Small Interfering RNA to Human Dendritic Cells To Suppress Dengue Virus Infection and Associated Proinflammatory Cytokine Production
Authors: Subramanya Sandesh , Kim Sang-Soo , Abraham Sojan , Yao Jiahong , Kumar Mukesh , Kumar Priti , Haridas Viraga , Lee Sang-Kyung , Shultz Leonard D. , Greiner Dale , N Manjunath , Shankar Premlata
Published: December 2009

Dengue is a common arthropod-borne flaviviral infection in the tropics, for which there is no vaccine or specific antiviral drug. The infection is often associated with serious complications such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), in which both viral and host factors have been implicated. RNA interference (RNAi) is a potent antiviral strategy and a potential therapeutic option for dengue if a feasible strategy can be developed for delivery of small interfering RNA (siRNA) to dendritic cells (DCs) and macrophages, the major
in vivo
targets of the virus and also the source of proinflammatory cytokines. Here we show that a dendritic cell-targeting 12-mer peptide (DC3) fused to nona-
d
-arginine (9dR) residues (DC3-9dR) delivers siRNA and knocks down endogenous gene expression in heterogenous DC subsets, (monocyte-derived DCs [MDDCs], CD34
+
hematopoietic stem cell [HSC])-derived Langerhans DCs, and peripheral blood DCs). Moreover, DC3-9dR-mediated delivery of siRNA targeting a highly conserved sequence in the dengue virus envelope gene (siFvE
D
) effectively suppressed dengue virus replication in MDDCs and macrophages. In addition, DC-specific delivery of siRNA targeting the acute-phase cytokine tumor necrosis factor alpha (TNF-α), which plays a major role in dengue pathogenesis, either alone or in combination with an antiviral siRNA, significantly reduced virus-induced production of the cytokine in MDDCs. Finally to validate the strategy
in vivo
, we tested the ability of the peptide to target human DCs in the NOD/SCID/IL-2Rγ
−/−
mouse model engrafted with human CD34
+
hematopoietic stem cells (HuHSC mice). Treatment of mice by intravenous (i.v.) injection of DC3-9dR-complexed siRNA targeting TNF-α effectively suppressed poly(I:C)-induced TNF-α production by DCs. Thus, DC3-9dR can deliver siRNA to DCs both
in vitro
and
in vivo
, and this delivery approach holds promise as a therapeutic strategy to simultaneously suppress virus replication and curb virus-induced detrimental host immune responses in dengue infection.
Genetic and Pathobiologic Characterization of Pandemic H1N1 2009 Influenza Viruses from a Naturally Infected Swine Herd
Authors: Weingartl Hana M. , Berhane Yohannes , Hisanaga Tamiko , Neufeld James , Kehler Helen , Emburry-Hyatt Carissa , Hooper-McGreevy Kathleen , Kasloff Samantha , Dalman Brett , Bystrom Jan , Alexandersen Soren , Li Yan , Pasick John
Published: December 2009

Since its initial identification in Mexico and the United States, concerns have been raised that the novel H1N1 influenza virus might cause a pandemic of severity comparable to that of the 1918 pandemic. In late April 2009, viruses phylogenetically related to pandemic H1N1 influenza virus were isolated from an outbreak on a Canadian pig farm. This outbreak also had epidemiological links to a suspected human case. Experimental infections carried out in pigs using one of the swine isolates from this outbreak and the human isolate A/Mexico/InDRE4487/2009 showed differences in virus recovery from the lower respiratory tract. Virus was consistently isolated from the lungs of pigs infected with A/Mexico/InDRE4487/2009, while only one pig infected with A/swine/Alberta/OTH-33-8/2008 yielded live virus from the lung, despite comparable amounts of viral RNA and antigen in both groups of pigs. Clinical disease resembled other influenza virus infections in swine, albeit with somewhat prolonged virus antigen detection and delayed viral-RNA clearance from the lungs. There was also a noteworthy amount of genotypic variability among the viruses isolated from the pigs on the farm. This, along with the somewhat irregular pathobiological characteristics observed in experimentally infected animals, suggests that although the virus may be of swine origin, significant viral evolution may still be ongoing.
CHOLINE DEFICIENCY IN THE GUINEA PIG
Authors: Young R. J. , Lucas C. C.
Published: December 2009

Young guinea pigs (4–6 days of age) fed a choline-deficient diet grew slowly and died within 3 to 4 weeks, at which time the livers showed only traces of stainable fat. Animals fed the diet supplemented with choline grew at the rate of 5.5 to 6.0 g. per day. Guinea pigs transferred from a complete diet to a choline-deficient diet after 3 to 4 weeks suffered an immediate retardation in growth but no mortality occurred (up to 6 weeks). A decrease in total body fat was noted. After 4 weeks, stainable fat was present in the liver. A small but definite increase in total liver fat occurred at 6 weeks. The guinea pig, like the chick, is unable to place the first methyl group on the ethanolamine moiety of choline, but betaine plus monomethylaminoethanol was as effective as choline in overcoming a deficiency of the latter.
EFFECT OF ALLOXAN, INSULIN, AND THYROXINE ON CHOLESTEROL AND FATTY ACID SYNTHESIS BY RAT LIVER HOMOGENATES
Authors: Scaife J. F. , Migicovsky B. B.
Published: December 2009

The in vitro effect of alloxan and insulin on the synthesis of cholesterol and fatty acids from 1-C14-sodium acetate by rat liver homogenates has been examined. Alloxan caused a reduction in the incorporation of acetate into cholesterol, fatty acids, and C14O2, but an increase in the oxygen consumption and carbon dioxide production. The addition of insulin to homogenates caused a reduction in cholesterol synthesis but an increase in fatty acid synthesis both for normal and diabetic animals. Homogenates from thyrotoxic rats exhibited a marked reduction in cholesterol synthesis when compared with normal animals. C14O2production by homogenates from starved rats was appreciably lower than for those from normal animals. With this exception no appreciable difference was found in the oxygen uptake, carbon dioxide, or C14O2production in homogenates from normal, starved, thyroxine-treated, or diabetic animals. Synthesized cholesterol was found to be located principally in the particulate matter of the homogenates after they had been incubated with 1-C14-sodium acetate. Homogenates from starved rats showed no greater tendency to degrade preformed cholesterol during incubation than did those from normal rats.
THE METABOLISM OF 2-C14-ADENINE IN THE RAT
Authors: Zbarsky S. H. , Paterson A. R. P.
Published: December 2009

The metabolism of 2-C14-adenine has been studied in the rat. Following intraperitoneal injection of the labelled material, isotope was found in the adenine and guanine of the visceral nucleic acids. Allantoin was the major radioactive metabolite excreted in the urine, and radioactive adenine and uric acid were also shown to be present. The finding of radioactivity in the urinary urea indicated a significant metabolic conversion of the 2-carbon of adenine to carbon dioxide. This result agreed with the finding of 8.5–9.4% of the injected radioactivity in the respiratory carbon dioxide. Possible mechanisms whereby carbon 2 of adenine may be metabolized to carbon dioxide are discussed.
THE EFFECT OF INGESTED CHLORTETRACYCLINE ON SOME HYDROLASES AND ORGANS ASSOCIATED WITH THE DIGESTIVE PROCESS IN GROWING PIGS: I. ASSAY METHODS FOR PROTEASE, AMYLASE, AND CELLULASE ACTIVITY
Authors: Vonk M. A. A. , McElroy L. W. , Berg R. T.
Published: December 2009

Methods are described for the determination of protease, amylase, and cellulase activity of unknown solutions permitting accurate measurements over a wide range of enzyme concentration in a single determination. Regression equations were obtained relating: (a) protease concentrations to the optical densities of casein hydrolyzates precipitated with an acetic acid solution (correlation coefficient, r = −0.9806; D.F. 70), (b) optical densities of starch–iodine complexes formed in starch hydrolyzates to amylase concentrations (multiple correlation coefficient, R = 0.9918; D.F. 62), and (c) cellulase concentrations to relative viscosities of carboxymethyl cellulose hydrolyzates (correlation coefficient, r = −0.9554; D.F. 34). The influence of chlortetracycline on the activity of these hydrolases in vitro was investigated and no effect was detected at a level of 5 p.p.m.
BIOSYNTHESIS OF QUERCETIN IN BUCKWHEAT: PART II
Authors: Watkin J. E. , Underhill E. W. , Neish A. C.
Published: December 2009

Various C14-labelled compounds were administered to Fagopyrum tataricum. After allowing 24 hours for metabolism the quercetin was isolated and degraded, by a modified alkaline fusion, into phloroglucinol (ring A) and protocatechuic acid (ring B plus carbon 2). Uniformly labelled sucrose or C14O2 (assimilated photosynthetically) formed quercetin equally labelled in the A and B rings, but sodium acetate-1-C14 (or acetate-2-C14) gave quercetin labelled almost entirely in ring A. Isotope competition experiments indicated meso-inositol and phloroglucinol were not precursors of ring A. The biosynthesis of quercetin from C14O2 or acetate required the combined action of stem and leaves. Light was not required for synthesis of quercetin from acetate.
FRACTIONATION OF LIVETIN AND THE MOLECULAR WEIGHTS OF THE α- AND β-COMPONENTS
Authors: Martin W. G. , Vandegaer J. E. , Cook W. H.
Published: December 2009

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2sec.−1volt−1at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104for α-livetin, and 4.8, 5.0, and4.5 × 104for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.
THE EFFECT OF VARIOUS DENATURANTS ON THE HAEMOGLOBINS OF ADULT AND CORD BLOOD: I. COMPARATIVE RATES OF DENATURATION
Authors: White F. D. , Kerr Audrey
Published: December 2009

At room temperature and pH 8.5, the effects of concentrated solutions of urea, nicotinamide, guanidine, sodium benzoate, and sodium salicylate upon the haemoglobins of adult and cord blood have been followed spectrophotometrically. In all cases the reaction curves were similar to those of alkali denaturation, but differed in the rates of reaction and failure to show any marked difference in rate between adult and cord blood. In no instance was the rate for cord blood greater than the corresponding rate for adult blood. 'The velocity constants for these experimental conditions have been calculated.Except in the case of the nicotinamide reaction, absorption curves of the reaction products before and after reduction with sodium dithionite showed differences from the corresponding curves of alkali denaturation at pH 11.9. It is suggested this may indicate varying degrees of denaturation.
FURTHER STUDIES ON THE PURIFICATION OF ANTITHROMBIN AND HEPARIN COFACTOR
Authors: Monkhouse F. C. , Clarke D. W.
Published: December 2009

Recently a concentrate of antithrombin and heparin cofactor was obtained from beef plasma by adsorption with aluminum hydroxide, elution with phosphate buffer, and subsequent fractionation with ammonium sulphate. The material obtained contained alpha globulin and albumin. Various electrophoretic techniques have now been employed in an effort to separate and purify antithrombin and heparin cofactor from the concentrates. Patterns obtained on starch and on paper indicate that both antithrombin and heparin cofactor are found with the alpha globulins or associated lipoproteins. The most active fractions have been obtained by the use of a vertical curtain electrophoretic apparatus. In terms of activity per mg. of nitrogen, antithrombin has been purified 7.5-fold and heparin cofactor 130-fold over the concentrates prepared by ammonium sulphate fractionation of phosphate eluates.
AN ACCURATE METHOD FOR THE ESTIMATION OF LOW CONCENTRATIONS OF DEXTRAN IN PLASMA
Authors: Semple Robert E.
Published: December 2009

A method is presented for the determination in plasma of small (50–150 mg./100 ml.) amounts of dextran. The procedure, which requires between 3 and 4 hours, consists of protein precipitation, glucose removal by dialysis, and the determination of the carbohydrate concentration of the resulting aqueous extract by a modified anthrone technique. Results of in vitro tests show that average dextran recovery is essentially 100% and that standard deviations in recovery range from 1.7 to 2.5% depending upon the dextran concentration. Deviations are reduced to a range of 1.4–1.7% by the use of duplicate plasma samples.
DISTRIBUTION OF ADRENOCORTICOTROPHIC HORMONE IN THE PITUITARY GLAND
Authors: Rochefort G. J. , Saffran M.
Published: December 2009

The highly vascular, anteromedial zone of hog and beef pituitary glands, which is rich in basophilic cells, contains a concentration of ACTH from 4 to 13 times that found in the rest of the adenohypophysis. The concentration of ACTH can be correlated (r = 0.96) with the relative proportion of basophilic cells, supporting the view that the pituitary basophiles are the source of ACTH. The distribution of both basophiles and ACTH in the rat adenohypophysis is more uniform than in hog or beef glands. The posterior lobe of all species examined (rat, hog, beef, and man) contains small, but significant, amounts of ACTH.
REANIMATION OF RATS AFTER CARDIAC AND RESPIRATORY ARREST DUE TO LOW BODY TEMPERATURE
Authors: Hunter John
Published: December 2009

In confirmation of the report by Andjus (1951) it has been found possible to reanimate rats that have been cooled to 2°–3 °C. and maintained at this temperature for periods up to 1 hour without cardiac or respiratory activity. The accumulation of metabolic carbon dioxide within the sealed vessel is an important part of the procedure if subsequent reanimation is to be attained. When the carbon dioxide is absorbed during the cooling phase, the animals remain active, their fall in body temperature is delayed and they do not recover from the hypothermia.Preliminary rewarming of the chest was unnecessary in the reanimation procedures described but rapid rewarming of the animal seems advantageous. The animals do not recover unless they are ventilated artificially when they are being rewarmed.
THE ROLE OF THE RETICULOENDOTHELIAL SYSTEM IN THE DISAPPEARANCE PATTERN OF EVAN'S BLUE DYE (T-1824) FROM CIRCULATING PLASMA
Authors: Greve Doreen M. , Hamilton Lyle H.
Published: December 2009

The disappearance of Evan's blue dye (T-1824) from plasma of dogs and rabbits has been followed for 4 hours in normal and T-1824 pretreated animals. One group of rabbits was pretreated with Thorotrast and the T-1824 disappearance studied for 1 hour. In both species of animals the disappearance pattern consisted of an early rapid fall in plasma dye concentration (Phase I) which was followed by a slower disappearance rate (Phase II). Phase I lasted approximately 30 minutes in dogs and slightly longer in rabbits and was curvilinear on a semilogarithmic plot. The disappearance rate during this period was markedly reduced by reticuloendothelial system (RES) blockade induced by pretreatment with T-1824 or Thorotrast. Phase II was characterized by a linear disappearance rate on semilogarithmic plot. It was more rapid in rabbits than in dogs and was unaffected in either species by RES blocking agents. The findings suggested that the RES was involved only in the first phase of T-1824 removal from plasma and that T-1824 was as effective as Thorotrast in blocking granulopexic activity of the RES.
ELECTROLYTE METABOLISM IN THE RAT EXPOSED TO A LOW ENVIRONMENTAL TEMPERATURE
Authors: Baker D. G. , Sellers E. A.
Published: December 2009

Some aspects of electrolyte metabolism in the rat exposed to a low environmental temperature have been examined. The first day of exposure at 2 °C. was accompanied by a loss of chloride. Continued exposure to cold resulted in a retention of sodium, and to a lesser extent, of potassium. Exposure to cold for 45 days (at 2 °C.) caused a sustained elevation of concentration of sodium in the plasma, with a transient increase in potassium and no change in the chloride concentration. Prolonged exposure to cold resulted in an increased blood volume and total body water content. These observations suggest that the rats acclimatized to cold have a larger proportion of actively metabolizing tissues than do comparable animals at room temperature.
A POSSIBLE MECHANISM FOR FATTY ACID INHIBITION OF CHOLESTEROL SYNTHESIS
Authors: Wood J. D. , Migicovsky B. B.
Published: December 2009

Further investigations have been carried out on the fatty acid inhibition of cholesterol biosynthesis in rat liver homogenates. A correlation appears to exist between cholesterol inhibition and the elongation of the carbon chain of saturated fatty acids containing an even number of carbon atoms. Neither saturated nor unsaturated fatty acids interfere with the formation of acetyl CoA by liver homogenate. The stage where acetoacetate is formed from acetyl CoA is suggested as a possible site for inhibition of cholesterol synthesis by fatty acids.
SITES OF FORMATION OF PLASMA PHOSPHOPROTEIN AND PHOSPHOLIPID IN THE ESTROGENIZED COCKEREL
Authors: Vanstone W. E. , Dale D. G. , Oliver W. F. , Common R. H.
Published: December 2009

Estrogen increased plasma Ca, but not plasma total protein, phosphoprotein P, or phospholipid P, in functionally hepatectomized cockerels. Estrogen increased all four plasma constituents in sham-operated cockerels. Functional hepatectomy of the estrogenized cockerel abolished incorporation into plasma phosphoprotein of injected orthophosphate labelled with P32, and reduced but did not abolish incorporation of P32into plasma phospholipid. These observations are submitted as direct evidence that plasma phosphoprotein in the estrogenized cockerel is exclusively hepatic in origin.
A ROUTINE PROCEDURE FOR THE DETERMINATION OF CATECHOLAMINES IN URINE AND TISSUES
Authors: Sourkes Theodore L. , Drujan Boris D.
Published: December 2009

A simplified procedure for the determination of catecholamines, suitable for routine laboratory use, has been developed. The whole of the adsorption–elution process, by which the catecholamines are concentrated and purified, is performed in one flask. The potentiometric titration required at this stage in the adsorption of the catecholamines on alumina is avoided by the use of phenol-phthalein as an internal indicator. The fluorimetric estimation in the second stage of the procedure is based upon lutin formation, a reaction nearly specific for adrenaline and noradrenaline. The small error resulting from the presence of hydroxytyramine in the urine is discussed. The method provides for the determination of losses encountered in the extraction process, so that each run includes an internal correction rather than an assumed average factor. Examples of the utility of the method are given. These include the determination of the rate of excretion of catecholamines in the urine, the effect of insulin on this rate, and the estimation of the catecholamine content of rat organs.
STUDIES ON THE SULPHUR METABOLISM OF TISSUES CULTIVATED IN VITRO: III. INTERRELATIONSHIPS BETWEEN CYSTEINE, METHIONINE, CYSTEAMINE, AND CYSTAMINE
Authors: Morgan Joseph F. , Morton Helen J.
Published: December 2009

Previous studies on the sulphur amino acid requirement of freshly-explanted chick embryonic heart tissues cultivated in vitro in completely synthetic media have been extended. The essential requirement for L-cystine has been found to be replaceable by L- but not by D-cysteine. In the presence of L-cysteine, the supplementary methionine requirement was found to be satisfied equally by the L- or D-isomer. Of eight derivatives and metabolites of cysteine studied, only cysteamine showed any significant ability to replace cysteine or cystine. The activity of cysteamine was exhibited only in the presence of methionine. High levels of cysteamine were found to be strongly toxic and the toxicity could be reversed specifically by L-cysteine. Significantly less reversal of the cysteamine toxicity was effected by L-cystine, while other sulphydryl and disulphide compounds were ineffective. Cystamine was also found to be toxic to the tissue cultures and its toxicity could be reversed completely by L-cysteine and incompletely by L-cystine.
STUDIES ON THE PRESERVATION OF BLOOD: V. THE INFLUENCE OF THE HYDROGEN ION CONCENTRATION ON CERTAIN CHANGES IN BLOOD DURING STORAGE
Authors: Kashket Shelby , Rubinstein David , Denstedt Orville F.
Published: December 2009

The hexokinase of the erythrocyte has two optima of activity, a pronounced one at pH 7.8 and a lesser one at pH 6.0. Glycerate-2,3-diphosphatase of the red cell similarly has two sharp optima, at pH 7.0 and 8.1, respectively. From pH 7.2 to 7.8 the activity of the diphosphatase is very low. During storage of blood with the citrate–dextrose (CD) medium at 4 °C. the pH of the samples falls from about pH 7.4 to 6.9, by the end of the fourth week. When blood is preserved with the acidified citrate–dextrose (ACD) medium, the pH falls from about 7.1 to 6.5 in the same period. The content of 2,3-diphosphoglycerate and the diminution in the activity of the hexokinase of the red cells are related to the change in the pH of the blood during storage. The significance of these changes is discussed.
THE RATE OF DISCHARGE OF ADRENOCORTICOTROPHIC HORMONE AS DETERMINED BY TIMED HYPOPHYSECTOMY IN THE RAT
Authors: Long C. N. H. , Bonnycastle M. F. M.
Published: December 2009

The pattern of secretion of adrenocorticotrophic hormone (ACTH) has been studied by opening the pituitary fossa of rats 36 hours before unilateral adrenalectomy. At selected intervals afterwards, the pituitary gland was removed and the effect on the fall in the ascorbic acid content of the remaining adrenal gland was determined. It was found that ACTH discharge is initiated with great rapidity and that the secretory pattern is a biphasic one. The first phase continues for about 5 minutes and then declines. It is succeeded by a second period of secretion that is much more prolonged. It is suggested that these results support the view that both a neural or neural–humoral and a purely humoral mechanism participate in the regulation of ACTH secretion.
A NEW CONCEPT OF THE METABOLISM OF THE PATHOLOGICAL PROTEINS IN MYELOMATOSIS
Authors: Neufeld A. H.
Published: December 2009

The principal features of myelomatosis are the presence of abnormal globulins in the blood and of pathological cells resembling plasma cells in the bone marrow. Disappearance studies with patients' own and with normal adults' I-131 labelled albumin and globulins showed that the time was shortened for the disappearance of the pathological globulins in the patients, whereas that of all other fractions in the controls and in the patients was normal. Incubation studies have shown that the bone marrow plays some part in the breakdown of these pathological proteins and in one experiment there is suggestion that, in the disease, the liver may be involved in the synthesis of these abnormal globulins.
FLUID, ELECTROLYTE, GASTROINTESTINAL, AND HAIR CHANGES IN ADRENALECTOMIZED-SYMPATHECTOMIZED DOGS
Authors: Cleghorn R. A. , Fowler J. L. A.
Published: December 2009

Five male dogs were adrenalectomized and sympathectomized and maintained by adrenocortical extract for periods of weeks to months. Their general behavior did not differ from those subject to adrenalectomy alone, but in three it was observed that the hair grew long and curly. In the other two a lesser change may have been missed. Following withdrawal of the hormone, death occurred rather suddenly in three, and adrenal insufficiency developed sooner in the other two than in dogs only adrenalectomized. Pathological changes in the gastrointestinal tract were qualitatively the same following death after hormone withdrawal in the adrenalectomized–sympathectomized animals and in dogs only adrenalectomized. Blood changes appeared to be no different in the two groups. The urinary changes with respect to water and electrolytes differed in that the sympathectomized group appeared to take in less water and excrete less urine, but to put out more sodium and chloride, in the few days following withdrawal of hormone. These findings are discussed in particular with respect to the relationship of adrenergic function of the sympathetic nervous system and hormones of the adrenal cortex.
THYROTROPHIN ASSAY BY PLASMA I131 MEASUREMENTS
Authors: Adams D. D. , Purves H. D.
Published: December 2009

The thyrotrophin assay, based on measurement of the effect of the hormone in causing a rise in the plasma I131 level of thyroxine-injected guinea pigs, has been studied further. The dose–response relationship from 0.0001 to 0.015 International Units of thyrotrophin is described. It is directly proportional from 0 to 0.0006 I.U., and closely approximates linearity over any threefold range of dosage from 0.0006 to 0.015 I.U. A modified design for the assay is suggested, embodying this knowledge of the dose–response relationship and the use of a Latin square arrangement to eliminate much of the unwanted variation. The proved limit of detection is 0.0001 I.U., the minimum concentration detectable being 0.00005 I.U. per ml., when 2 ml. of test material is injected. Accurate assays can be performed with small numbers of animals.
AMINO ACIDS IN THE BLOOD AND URINE OF NORMAL AND ARTHRITIC SUBJECTS BEFORE AND AFTER A GLYCINE LOAD GIVEN WITH AND WITHOUT ADRENOCORTICOTROPIN
Authors: Derrick J. B. , Hanley Audrey P.
Published: December 2009

Observations have been made on the specific free amino acids (chromatographic analysis) and other nitrogenous constituents in the serum and urine of normal and arthritic men under controlled dietary conditions, before and after a glycine load and adrenocorticotropin administered separately and together.Differences in the metabolism of amino acids between normal individuals and arthritics, particularly of alanine, proline, glutamic acid, taurine, and possibly tyrosine (and/or tryptophan) and cystine, were apparent. The differences were largely confined to the non-essential amino acids. Concomitant increases seen in the serum levels and in the excretion of several amino acids, in response to a load of a single amino acid, indicate that the increases in excretion are more than a matter of competition for reabsorption in the kidney. A prerenal phenomenon appears to be involved, possibly interconversion of amino acids. This concept is supported by the evidence that the increases in the serum levels were restricted to the non-essential amino acids.
THE ESTIMATION OF CALCIUM AND MAGNESIUM
Authors: Campbell Walter R.
Published: December 2009

A description of a device for measuring calcium and magnesium in body fluids by means of versene and organic dyes is given together with methods of operating the instrument, preparing standards, and purifying the reagents. The method is more precise than older methods used in clinical laboratories for estimating calcium and magnesium, requires very much less time, and, with suitable modifications, is applicable in water analyses for assessing the hardness due to the presence of these metals. The method could be further refined for use with small animals or in circumstances where only small amounts of body fluids are available.
THE DETECTION OF ESTROGENIC ACTIVITY IN TISSUES OF STEERS WHICH HAVE BEEN FED DIETHYLSTILBESTROL
Authors: Wiberg G. S. , Stephenson N. R.
Published: December 2009

The immature female rat was used to detect estrogenic residues in the tissues of cattle fed a ration containing diethylstilbestrol. The criterion of response to the estrogen was the increase in uterine weight which resulted from the ingestion of the beef tissues. The weanling rat was twice as sensitive as the ovariectomized mouse to oral diethylstilbestrol. Significant levels of the estrogen were found in lean meat, liver, and kidney 24 hours after the removal of the diethylstilbestrol from the steers' diet, but such residues could not be detected when this period was extended to 48 hours.
UPTAKE OF RADIOACTIVE SULPHUR BY VARIOUS TISSUES OF NORMAL AND CHOLESTEROL-FED RABBITS
Authors: Buck R. C. , Heagy F. C.
Published: December 2009

The uptake of inorganic sulphur labelled with radioactive sulphate (S35) was studied in rabbits that had been fed a normal diet and rabbits that had been fed a similar diet supplemented by the addition of 1% of cholesterol for 4 months. Paper electrophoresis of alkaline extracts of cartilage, tendon, or aorta separated a peak of radioactivity that corresponded to a band that stained metachromatically with toluidine blue and that is assumed to be chondroitin sulphate. Characteristic peaks of radioactivity were found by electrophoresis of extracts of mucin-containing tissues of the gastrointestinal tract, indicating the location of sulphated mucus with a mobility different from that of chondroitin sulphate. No radioactive material was isolated from the tissues of cholesterol-fed animals that was not present in normal tissues. Highly significant over-all differences in specific activity of sulphur were found between various tissues in both normal and cholesterol-fed rabbits. A significant elevation of both specific activity and sulphur concentration was produced in the aorta as a result of cholesterol feeding.
THE ESTIMATION OF MALEIC HYDRAZIDE BY PAPER CHROMATOGRAPHY
Authors: Andreae W. A.
Published: December 2009

Maleic hydrazide added to solutions of partially purified plant extracts can be determined semiquantitatively by a paper chromatographic method in which the area of the maleic hydrazide spot, detected by spraying with a mixture of ferric chloride and potassium ferricyanide, is measured. By this method as little as 0.2 micrograms of maleic hydrazide can be detected with an error of about 35%. This method is not applicable to plants treated with maleic hydrazide because of the presence of interfering substances.
THE DETERMINATION OF THE AVAILABLE CALORIC CONTENT OF RAPESEED OIL BY RAT GROWTH
Authors: Middleton E. J. , Campbell J. A.
Published: December 2009

The available metabolic energy of rapeseed oil, semihydrogenated rapeseed oil, and corn oil was measured in terms of 7-day body-weight gains of weanling rats fed a calorically restricted diet. Standard bio-assay procedures were used with lard as a reference standard. The oils were fed at three levels equivalent to 5, 9, and 17% of the diet by weight. Growth responses to the three oils and to lard were similar and the calculated caloric content of the oils showed no significant difference from that of lard. A 1 week assay was as precise as a 5 week assay.