bluuebunny/crossref_metadata_2025 huggingface dataset:
DIETARY FACTORS AFFECTING THE LEVEL OF PLASMA CHOLESTEROL IN HUMANS: THE ROLE OF FAT
Authors: Beveridge J. M. R. , Connell W. F. , Mayer G. A.
Published: December 2009

Three dietary experiments have been performed in which 36, 37, and 49 male medical students and staff members participated as experimental subjects. In each study, everyone consumed the same homogeneous formula diet for eight days at which time they were divided into five groups. One group was maintained on the original diet for a further eight days and the others were given diets varying in respect of the level and nature of the fat moiety. Protein supplied 16.9% of total calories in all experimental rations. In the first experiment, 37 subjects ingested a diet providing 58.5% of calories as corn oil. During the initial period the average of the individual percentage decreases in plasma cholesterol was 32.0 (P = < 0.01). Those continuing on corn oil displayed a further insignificant decrease. The others, receiving diets high in beef dripping, chicken fat, lard, and butter showed average individual percentage increases of 11.7 (P = > 0.05), 12.7 (P = > 0.05), 15.4 (P = < 0.01), and 28.8 (P = < 0.01), respectively. In the second experiment, 49 subjects consumed a fat-free diet for eight days. The average individual percentage decrease in plasma cholesterol was 22.2 (P = < 0.01). Those continuing on the fat-free diet showed little further change. Those ingesting 20 and 60% of calories as corn oil showed further percentage decreases of 6.9 (P = > 0.05) and 15.2 (P = < 0.01), respectively. By contrast, those receiving diets providing 20 and 60%, of calories as butterfat showed respectively percentage increases of 6.6 (P = > 0.05) and 21.7 (P = < 0.01). In the third experiment, 36 subjects ingested for eight days a diet in which butterfat provided 60% of calories. The plasma cholesterol level remained essentially constant, and did not change significantly in those continuing on this diet for a further eight days. The composition of the fat moiety in the remaining groups in terms of per cent calories derived from butter-fat and corn oil respectively was: 45: 15; 30: 30; 15: 45; and 0: 60. The averages of the individual percentage decreases in plasma cholesterol values were, respectively, 3.9, 15.9, 27.1, and 32.0. Except for the lowest of these values all the changes are highly significant (P = < 0.01). In addition to other conclusions that may be drawn from this work, these studies reveal that (1) there is a factor (or are factors) in certain animal fats that acts to elevate plasma cholesterol levels, and (2) there is a factor (or are factors) in corn oil that acts to depress plasma cholesterol levels.
STUDIES OF CERTAIN ANTIHISTAMINES AS ANTAGONISTS OF THE HYPERTENSIVE AND ANGIOTOXIC PROPERTIES OF DESOXYCORTICOSTERONE ACETATE IN THE RAT
Authors: Skelton Floyd R.
Published: December 2009

Three antihistamine agents, Phenergan, Benzodionole, and Trimeton have been studied for their ability to antagonize the hypertensive and cardiovascular-renal effects of desoxycorticosterone acetate in the unilaterally-nephrectomized, salt-treated, castrate male rat. In the order named all compounds produced only slight inhibition of the hypertensive and cardiotrophic action of desoxycorticosterone acetate and afforded virtually no protection against either the nephrotrophic or angiotoxic effects of this steroid as seen in the kidney, heart, and pancreatic, arterioles.
METABOLISM OF GLUCOSE AND STEROID FORMATION BY RAT ADRENALS IN VITRO
Authors: Schönbaum E. , Birmingham Marion K. , Saffran Murray
Published: December 2009

The stimulation by ACTH of the formation of corticoids by rat adrenals in vitro is enhanced by the presence of glucose in the medium. Pyruvate and ribose also enhance the stimulation by ACTH, but to a lesser extent; acetate, acetoacetate, and β-hydroxybutyrate are without detectable influence. The following inhibitors decrease or abolish the effect of ACTH: iodoacetate, fluoride, arsenite, N2 (anaerobiosis), cyanide, azide, and dinitrophenol. A decrease in the sodium: potassium ratio of the medium also results in the inhibition of the stimulation of corticosteroid formation by ACTH. Fluoroacetate, trans-aconitate, malonate, and benzoate exert a less marked influence on the formation of corticoids. Epinephrine and insulin are without effect.
IDENTIFICATION OF A HYPERGLYCEMIC FACTOR IN URINE
Authors: Moya F. , Szerb J. C. , MacIntosh Margaret
Published: December 2009

The precipitate obtained by the addition of two volumes of ethanol to acidified human urine (APU) has been previously found to be hypotensive and hyperglycemic when injected into rabbits. The experiments reported show that the hypotensive action of APU is not inhibited by atropine or antihistamine compounds. Following preincubation for one minute, a mixture of blood serum and APU contracts the guinea pig ileum. This action is not inhibited by atropine, antihistamine compounds, or soybean trypsin inhibitor. APU, per se, is not a smooth-muscle stimulant. Following prolonged incubation with serum, APU loses its hypotensive and hyperglycemic properties. Padutin, a commercial preparation of the hypotensive agent kallikrein, has been shown to be hyperglycemic in the rabbit and this action can be prevented by ergotamine. The experiments reported indicate that the hypotensive agent present in APU is probably kallikrein and that it is indirectly responsible for the hyperglycemic response elicited by the extract. From the chemical properties of kallikrein it appears likely that it is responsible for the reported hyperglycemic action of urinary extracts prepared by a variety of procedures.
STUDIES ON THE EFFECTS OF PHAGOCYTIC STIMULATION ON MICROBIAL DISEASE: V. STIMULATION OF PHAGOCYTIC ACTIVITY OF MONOCYTES AGAINST TUBERCLE BACILLI, STRAIN BCG
Authors: Gözsy Béla , Kátó László
Published: December 2009

Monocytes were obtained by the washing of the peritoneal cavity of guinea pigs with Hanks' solution six days after intraperitoneal administration of a saline solution containing glycogen. Phagocytosis of tubercle bacilli (BCG strain) was studied after a one hour incubation at 37 °C. under the influence of histamine and 1,4-dimethyl-7-isopropyl-bicyclo-decapentane, which latter substance had shown a beneficial influence on the outcome of experimental tuberculosis. Histamine increased the phagocytic activity of monocytes, within the limits of 1 μgm. to 10 μgm per ml. This stimulation was inhibited in vitro by a synthetic antihistamine substance. Fifty and 100 μgm. per ml. histamine decreased the phagocytosis of tubercle bacilli (BCG) by the monocytes. Monocytes withdrawn from histamine treated guinea pigs showed no stimulated activity. From 0.5 to 100 μgm. per ml. of 1,4-dimethyl-7-isopropylbicyclo-decapentane stimulated the phagocytic activity of monocytes against tubercle bacilli (BCG) in vitro and monocytes withdrawn from animals treated with the same substance showed equally a stimulated activity. This increased phagocytosis was equally inhibited in vitro by the antihistamine, but to a lesser degree than the inhibition of the histamine stimulated phagocytosis. The above observations suggest that the stimulating action of the 1,4-dimethyl-7-isopropyl-bicyclo-decapentane is a direct action on the monocytes rather than an indirect one caused by activation of latent histamine. Experiments also show the possibility of stimulation of the cellular defense mechanism, by appropriate treatment.
THE ABSORPTION OF LABELLED GLUCOSE, SODIUM GLUCURONATE, AND GLUCURONE FROM THE GASTROINTESTINAL TRACT OF THE RAT
Authors: Packham Marian A.
Published: December 2009

The absorption of labelled glucose, sodium glucuronate, and glucurone from the gastrointestinal tract of the rat was studied by measuring the amount of C14 remaining in the tract at various times after oral administration. The rate of expiration of labelled carbon dioxide was also determined. Glucose was rapidly absorbed from the small intestine, but sodium glucuronate and glucurone behaved similarly and did not begin to disappear from the gut until they had reached the large intestine. The results of these and previous experiments led to the conclusion that very little glucuronate was absorbed as such but that most of it was changed into other compounds before absorption.
FURTHER STUDIES ON THE ABSORPTION SPECTRA OF STEROIDS IN "100%" PHOSPHORIC ACID
Authors: Nowaczynski Wojciech J. , Steyermark Paul R.
Published: December 2009

Absorption maxima and minima of 67 steroids, after treatment with "100%"phosphoric acid, are tabulated together with their optical densities. Some correlations between the structure and the spectra of steroids are demonstrated with the aid of simple model compounds. An example of the application of the technique to the characterization of steroids from natural sources is quoted.
COMPARATIVE BIOCHEMICAL STUDIES ON NORMAL AND ON POLIOMYELITIS INFECTED TISSUE CULTURES: II. INVESTIGATION OF VARIOUS ENZYME SYSTEMS IN HOMOGENATES OF KIDNEY TISSUE CULTURES OF NORMAL RHESUS MONKEYS
Authors: Kovacs E.
Published: December 2009

Pools of normal tissue cultures were examined for enzymes associated with nucleic acid metabolism. Ribonucleases and desoxyribonucleases, 5-nucleotidases, simple nucleotidases, acid and alkaline phosphatases were studied, and certain others occasionally demonstrated. Characteristic behavior of these enzyme systems during the cultivation procedures, during growth, and during degeneration was described. Quantitative data indicate the presence of significant amounts of enzymes in the supernatant fluid. This accounts for the considerable loss in these specialized constituents during fluid changes. The bearing of these findings on the physiology and pathology of cultivated cells was discussed, as a working hypothesis, with special emphasis on poliomyelitis infection. The use of enzyme assays, as functional tests supplementing morphological methods in tissue cultivation, was recommended.
MAINTENANCE OF BODY TEMPERATURE OF RESTRAINED ADRENALECTOMIZED RATS EXPOSED TO COLD: EFFECT OF ADRENAL CORTICAL HORMONES
Authors: Iampietro P. F. , Fregly M. J. , Buskirk E. R.
Published: December 2009

Experiments were performed to determine the role of the adrenal glands in the maintenance of colonic temperature of rats which were restrained and exposed to air at 5 °C. Colonic temperature decreased linearly with time in the cold air; hence, colonic cooling rate (CCR) was adopted as a measure of response to cold. Bilateral adrenalectomy increased CCR. Administration of cortisone acetate, adrenal cortical extract (ACE) or desoxycorticosterone acetate to adrenalectomized rats decreased CCR. Maximal decrease occurred with administration of 1.00 mgm. cortisone/rat/day or 0.25 ml. ACE/rat/day; higher doses of each hormone were less and less effective in returning CCR toward that of sham-operated rats. An adrenalectomized rat could not be rendered normal with respect to CCR no matter what dose of either ACE or cortisone was administered. In contrast, only the highest dose of DOCA administered (4.0 mgm./rat/day) significantly reduced CCR to that of sham-operated rats. The cooling test is similar to the standard growth test in that the response to administration of cortisone and ACE passes through a maximum and then declines with increasing dosage. The lower colonic temperature of adrenalectomized rats in air at 25 °C. was returned to that of sham-operated rats when cortisone (1.00 mgm. or more) or ACE (0.25 ml. or more) was administered; however, colonic temperature did not appear either to increase incrementally or to pass through a maximum with increasing doses of either hormone. DOCA had no effect on initial colonic temperature. Untreated adrenalectomized rats rarely survived lowering of colonic temperature to 22.5 °C; hence, the minimum colonic temperature to which adrenalectomized rats can be cooled and subsequently survive is considerably above that for normal rats (LD50 15.3 °C). Administration of any of the above hormones increased survival even in those doses which did not affect CCR.
THE OCCURRENCE OF ACETYLCHOLINE IN THE HOUSEFLY, MUSCA DOMESTICA L.
Authors: Chefurka W. , Smallman B. N.
Published: December 2009

The occurrence of acetylcholine in the heads of houseflies has been demonstrated. After a preliminary purification by paper electrophoresis, acetylcholine was identified by paper chromatography, paper electrophoresis, pharmacological methods, and by its reaction with hydroxylamine – ferric chloride. The base was also isolated as a reineckate, converted to the perchlorate, and its infrared spectrum shown to be identical with reagent acetylcholine.
SOME OBSERVATIONS CONCERNING THE BIOCHEMICAL INERTNESS OF METHYLPHOSPHONIC AND ISOPROPYL METHYLPHOSPHONIC ACIDS
Authors: Hoskin F. C. G.
Published: December 2009

Methylphosphonic acid is not degraded in the intact rat to phosphoric acid. The stability of isopropyl methylphosphonic acid in the intact rat has been confirmed. Rat muscle phosphorylase appears unable to catalyze the synthesis of hexose phosphonate esters from methylphosphonic or isopropyl methylphosphonic acids under conditions where hexose phosphate esters are readily synthesized from phosphoric acid.
THE EXTRACTABLE HEPARIN IN DIFFERENT ANIMAL TISSUE
Authors: Monkhouse Frank C.
Published: December 2009

Heparin is extracted from tissue by 0.5 M potassium thiocyanate. The protein is removed from the extract with 80% phenol and the heparin precipitated from the aqueous layer with three volumes of 95% ethanol. Further purification is achieved by reprecipitating the heparin with alcohol, dissolving the precipitate in saline, and precipitating it with 5% benzidine hydrochloride. The amount of heparin extractable by this method has been determined in a variety of tissues from rabbit, dog, beef, monkey, and man. The amounts expressed in units per 100 gm. of tissue varied from less than four units in the rabbit intestine to 4800 units in the liver of a hypophysectomized dog. Radioactive heparin was obtained from dog liver 48 hr. after the animal had been fed S35 contained in hydrolyzed yeast. The significance of these findings in relation to further studies on the physiological role of heparin is considered.
CHANGES IN THE ELECTROCARDIOGRAM AND HEART CHOLINE ESTER CONTENT OF THIAMINE-DEFICIENT AND PAIR-FED RATS
Authors: Beznák A. B. L.
Published: December 2009

The choline ester content of trichloroacetic acid extracts of thiamine-deficient, pair-fed, and normal rat hearts was determined by differential assays on the eserinized frog rectus and guinea pig gut. The thiamine-deficient hearts contained about 3.5 times more choline ester than the normal hearts, while the pair-fed ones about twice as much. It is concluded from results of differential assays and filter paper chromatography of the trichloroacetic acid extracts that the chief, probably the only, choline ester in all the three groups is acetyl choline. It is also pointed out that the possibility of the presence of a mixture of pyruvyl, propionyl, and acetyl choline in the thiamine-deficient heart could not be excluded with these methods. Bradycardia and increased R voltage develop both in thiamine-deficient and in pair-fed rats, but are more pronounced in the former group. When the three groups of rats, normal, pair-fed, and thiamine-deficient, were treated as a single population a positive correlation was found between R voltage and total ACh equivalent and an inverse correlation between heart rate and ACh equivalent. The trichloroacetic acid extracts of rat hearts of all the three groups contain a positive inotropic substance (or substances) and substances which absorb ultraviolet light, most probably nucleic acid derivatives, which interfere with the frog heart assay of choline esters. The ultraviolet absorbing compounds are the bearers of most of the positive inotropic activity. These can be separated from the negative inotropic choline esters by filter paper chromatography.
QUANTITATIVE CONCEPTS RELATED TO PROTHROMBIN AND AUTOPROTHROMBIN I ACTIVITY
Authors: Seegers Walter H. , Johnson Shirley A. , Penner John A.
Published: December 2009

It has been discovered that Russell viper venom can be combined with autoprothrombin I and calcium ions for the activation of purified prothrombin to thrombin provided a small amount of Ac-globulin is also in the reaction mixture. This observation has been utilized for developing a quantitative assay for autoprothrombin I concentration. Conditions are arranged so that the yield of thrombin from a purified prothrombin substrate is quantitatively related to the amount of autoprothrombin I in the reaction mixture. Normal human plasma contains about 21 units of autoprothrombin I, and serum contains about 39 units. It is estimated that about 8% of the prothrombin of plasma is converted to autoprothrombin I when blood clots in a test tube. By addition of purified platelet factor 3 to freshly drawn blood, the conversion of prothrombin to autoprothrombin I may involve more than two thirds of the prothrombin; and, by addition of thromboplastin to freshly drawn blood, about 50% of the prothrombin can be converted to autoprothrombin I. It is estimated that the autoprothrombin I concentration of plasma is from 1 to [Formula: see text] mgm. %
EFFECT OF TOLAZOLINE IN HEMORRHAGIC HYPOTENSION IN DOGS
Authors: Gowdey C. W. , Pearce J. W. , Stevenson J. A. F.
Published: December 2009

Adrenergic blocking agents have been found by several investigators to be beneficial in hemorrhagic shock under circumstances in which they can affect the volume of blood lost. In this study of the effect of the blocking agent tolazoline on the response to standardized hemorrhagic hypotension in the dog, in which a constant blood pressure is maintained by the reservoir method, no improvement in rate of survival was observed when an increase in blood volume in response to drug-induced vasodilatation was prevented. Nor did the stimulating effect of tolazoline on the heart improve survival, whether the drug was given during hypotension or at the time of reinfusion. When the blood reservoir was clamped off during the hypotensive period to prevent spontaneous changes in blood volume but not in blood pressure, the animals which were still able to increase their blood pressure survived after reinfusion whereas those which could not died, despite reinfusion of their original blood volume.
ERUCIC ACID AND CHOLESTEROL EXCRETION IN THE RAT
Authors: Carroll K. K. , Noble R. L.
Published: December 2009

Erucic acid has been found to increase the excretion of endogenously produced cholesterol in the rat with little change in the cholesterol concentration in the carcass except for increased concentrations in the adrenals and liver. The fecal cholesterol was identified by melting point and infrared spectrum after isolation by chromatography on alumina. It does not appear to originate in the liver since no increase was observed in the biliary excretion of cholesterol. Other homologues of oleic acid, namely eicosenoic and nervonic acid, produced similar changes in fecal cholesterol excretion, although oleic acid itself had little effect. A series of saturated fatty acids from butyric (C4) to behenic (C22) were tested and the longer chain members found to cause some increase in cholesterol excretion. Ester cholesterol accounted for much of the observed increases but varied greatly in the experiments with unsaturated fatty acids. A preparation of cerebrosides from beef spinal cord also increased the amount of cholesterol excreted in the feces. The fatty acid fraction from this preparation gave a similar result, although the cerebrosides gave rise mainly to free cholesterol and the fatty acid fraction to ester cholesterol.
SOME OBSERVATIONS ON THE MOLECULAR FORM OF CHONDROITIN SULPHATE
Authors: Webber R. V. , Bayley S. T.
Published: December 2009

The physical properties of a preparation of chondroitin sulphate extracted from bovine cartilage with calcium chloride have been measured at various stages of purification. After removal of free protein, the extract has a number-average molecular weight, from sedimentation and viscosity data, of about 1.0 × 106. After tryptic digestion, the molecular weight of the extract is 39,000 on a number average basis from sedimentation and viscosity data, and about 145,000 on a weight average basis from light scattering data. At both stages of purification, the extract is widely polydisperse and exhibits streaming birefringence in aqueous but not in salt solution. Before digestion, the particles evidently represent aggregates of polysaccharide molecules linked in an end-to-end arrangement by peptides; tryptic digestion partially destroys these peptide linkages. It does not appear, from a partial analysis of the amino acids present, that the origin of the protein or peptide material is collagen.
DETAILED STUDY OF A PURIFIED URINARY ALDOSTERONE FRACTION
Authors: Nowaczynski Wojciech J. , Steyermark Paul R. , Koiw Erich , Genest Jacques , Jones R. Norman
Published: December 2009

Extensive purification of an aldosterone fraction obtained after two chromatographic separations (Zaffaroni's propylene glycol/toluene system and Bush C system) from crude neutral extract is described. Highly purified aldosterone was isolated in four instances. At least four other compounds which may be related to aldosterone were found in this fraction. A procedure is proposed for the isolation and determination of highly purified aldosterone.
THE NON-ENZYMIC REDUCTION OF TRIMETHYLAMINE OXIDE TO TRIMETHYLAMINE, DIMETHYLAMINE, AND FORMALDEHYDE
Authors: Vaisey E. B.
Published: December 2009

Trimethylamine oxide at temperatures between 22°–24 °C. is readily reduced by cysteine in the presence of iron or hemoglobin as a catalyst. Trimethylamine is the major product of this reduction, but appreciable amounts of dimethylamine and formaldehyde are also formed. The maximum reduction of trimethylamine oxide is between pH 7 and 8. Glutathione could not replace cysteine as a reducing agent, neither could copper or manganese replace iron compounds as catalysts. Larger amounts of iron (Fe++) could also reduce trimethylamine oxide with the formation of the above products. A mechanism for the reaction is proposed.
THE EFFECT OF AUREOMYCIN ON THE PRODUCTION OF HEMORRHAGIC SHOCK IN THE RAT
Authors: Downie H. G.
Published: December 2009

Hemorrhage into the jejunum and ileum, especially in those areas where there were ingesta, was observed in an earlier study designed to standardize a method for the production of hemorrhagic shock in the rat. This type of lesion might permit entry of bacteria and toxins, thus fatally increasing the strain on the animal. In the present study aureomycin was administered orally, 50 mgm. daily in a single dose for three days, and the rats were submitted to the standardized shock procedure. In a second series the same procedure was followed but a fourth dose of 50 mgm. of aureomycin was administered five hours before hemorrhage. None of the indices measured indicated that aureomycin used in such a manner was effective in reducing the mortality, or the hemorrhage into the bowel.
EXPERIMENTS ON THE USE OF SILICIC ACID FOR STEROID CHROMATOGRAPHY
Authors: Linford J. H.
Published: December 2009

Mixtures of pure sterols, and extracts of hydrolyzed urine, were chromatographed on columns of silicic acid. The results were observed spectrometrically using a sulphuric acid – methanol color reagent. Dry silicic acid retained or altered the sterols. When the silicic acid contained free water the sterols were distributed between the surface of the solid and the developing solvent. The adherence to the solid phase decreased with increase of free water and with increased solubility of the sterol in the solvent. As the free water was increased liquid–liquid partition was observed. The adherence of the sterol to the silica surface increased with the number of hydroxyl groups in the sterol molecule. Silicic acid columns are therefore particularly suited to the separation of sterols that differ in their number of hydroxyl groups and to the detection of the production of artifacts by loss of the hydroxyl group.
EXTRACELLULAR ORGANIC NITROGEN IN USTILAGO MAYDIS FERMENTATION BROTHS
Authors: Dulaney Eugene L. , Bilinski E. , McConnell W. B.
Published: December 2009

Free amino acids and small peptides make up most of the extracellular organic nitrogen in media from shaken and aerated Ustilago maydis fermentations. Of the 3.5 mgm./ml. ammonia nitrogen added, 2.9 mgm./ml. remained in the extracellular broth. This extracellular nitrogen contained 1.17 mgm./ml. of organic nitrogen and 1.74 mgm./ml. of residual ammonia nitrogen. At least 53% of extracellular organic nitrogen is in the form of free amino acids. Fifteen amino acids were estimated quantitatively in acid-hydrolyzed broth and a particularly high level of arginine (1.14 mgm./ml.) was found. The amounts of methionine and tryptophan in the broth were quite low but the lysine concentration 0.400 mgm./ml. was relatively high.
KINETICS OF THE ENZYMICALLY-CATALYZED OXIDATION OF INDOLEACETIC ACID
Authors: Maclachlan G. A. , Waygood E. R.
Published: December 2009

A study of the kinetics of the enzymically-catalyzed decarboxylation and oxidation of indoleacetic acid has provided evidence that it is a chain autoxidation initiated and propagated by two enzyme-controlled peroxidations. The following reaction sequence occurs:[Formula: see text]where S—COOH = indoleacetic acid; S∙ = skatole radical; SO2∙ = oxidized skatole radical or indole peroxide; SO2H = final reaction product; ROH = phenolic cofactor, i.e., resorcinol; RO∙ = semiquinol or aryl radical.
FURTHER STUDIES ON THYROID - ADRENAL - ASCORBIC ACID RELATIONS IN ANIMALS EXPOSED TO COLD
Authors: DesMarais André
Published: December 2009

The effect of ascorbate administration on resistance to cold and thyroid function was studied in adrenalectomized rats receiving various amounts of cortisone and/or DCA; in thyroidectomized rats given different doses of of thyroxine, the effect of ascorbate administration was evaluated on both resistance to cold and adrenal function.In adrenalectomized rats given large doses of cortisone (2.5 mgm.) and exposed to cold, the administration of either ascorbate (150 mgm.) or DCA (2.5 mgm.) enhances the survival, reduces the extent of thymolysis, and decreases the activation of the thyroid. In adrenalectomized rats receiving no cortisone or DCA or low doses (0.4 and 0.1 mgm.) of these hormones, ascorbate administration (150 mgm.) still retains some of its beneficial effects on resistance to cold (better growth and survival); when low doses of DCA (0.1 mgm.) are given without cortisone, ascorbate administration seems to have a deleterious effect on the growth and survival during exposure to cold, with a greater increase in thyroid activity.In thyroidectomized rats exposed to cold, ascorbate administration (150 mgm.) has no effect in the absence of thyroxine, but increases the efficiency of low doses (3 μgm.) of thyroxine, preventing at the same time some of the typical signs of an alarm reaction: thymolysis and adrenal enlargement.These results are interpreted as showing that the role of the cortical hormones in resistance to cold might be limited to a "conditioning" action and that the beneficial effects of ascorbate administration would be mediated through the thyroid hormones.
STATISTICAL MECHANICS OF STATIC GRANULAR PACKINGS UNDER GRAVITY
Authors: CIAMARRA MASSIMO PICA , DE CANDIA ANTONIO , FIERRO ANNALISA , NICODEMI MARIO , CONIGLIO ANTONIO
Published: December 2009

Despite the large use of granular materials in the industry, and the large number of natural phenomena where granular materials are involved, a comprehensive theoretical framework of their physics is still missing. An important perspective was proposed almost 20 years ago by S.Edwards, which suggested the possibility of a statistical mechanics description of granular materials at rest in their mechanically stable states. This article focuses on the theoretical foundations and current understanding of a statistical mechanics approach of granular materials under gravity. Experimental and numerical results discussing such an approach and clarifying its limit of validity are described as well.
TERRESTRIAL VEGETATION COVER ACTIVITY AS A PROBLEM OF FLUCTUATING SURFACES
Authors: COPPOLA ROSA , CUOMO VINCENZO , D'EMILIO MARIAGRAZIA , LANFREDI MARIA , LIBERTI MARGHERITA , MACCHIATO MARIA , SIMONIELLO TIZIANA
Published: December 2009

The role of vegetation cover within the processes that link land and atmosphere is of stringent interest for the correct modeling of Climate dynamics. Temporal and spatial correlation of the terrestrial coverage varies according to Climate and acts as a major forcing on it through changes in surface energy and water balance as well as in the carbon cycle. Recent studies have enhanced the actual and potential impact of this forcing on the radiative balance thus evidencing effects that are at least comparable to that due to all the anthropogenic greenhouse gases together. At now, observational studies on land cover dynamics are strongly in progress thanks to satellite data. The availability of continuous observations of the land surface can allow us to understand the correlation structure, both in time and in space, that characterizes the land cover activity. Satellites provide time series of photosynthetic activity measures that can be regarded as a succession of observations of a two-dimensional scalar field. We exploited the paradigm of fluctuating surfaces as a mechanic analogue for our problem. To capture vegetation cover characteristic time-scales, persistence properties were evaluated by analysing annual maps of NDVI-AVHRR time series and persistence probability was estimated by using the sing-time distribution methodology. The analysis performed for ecoregions of Italian and Greek territories evidenced signatures of short range persistence with characteristic time scales that depend on land cover, climate, and anthropic activities. Our results confirm that such an approach can provide a useful parameterisation for including vegetation into climate models as a dynamical component.
ON THE FLUCTUATION-RESPONSE RELATION IN GEOPHYSICAL SYSTEMS
Authors: LACORATA GUGLIELMO , PUGLISI ANDREA , VULPIANI ANGELO
Published: December 2009

One of the major issues concerning the study of a dynamical system is the response to perturbations. In climate dynamics, for example, it is of major interest to understand how a given variable, e.g., the temperature, is sensitive to alterations of some other component of the system, e.g., the greenhouse gas concentration. We review the connection between equilibrium and non-equilibrium properties, also known as Fluctuation-Relaxation Relation, and its main aspects in chaotic and turbulent systems. We consider, in particular, the effects of the fast variables on the slow variables in a multiscale system, as far as the sensitivity properties are concerned. Two examples about (widely speaking) climate modelling are discussed: the Lorenz-96 model and the double-potential well model. Both of them, despite their apparent simplicity, hide the same kind of interesting features of much more complex systems.
ANALYSIS OF WATER LEVEL OSCILLATIONS BY USING METHODS OF NONLINEAR DYNAMICS
Authors: CAPUANO P. , DE LAURO E. , DE MARTINO S. , FALANGA M.
Published: December 2009

Sea level variations collected in several areas in the world have been analyzed trying to infer their non linear characteristics. Analyzed data were acquired in several sites in West and East coasts of the North American continent, in the Hawaii and Bermuda islands, representing oceanic sites, and in Adriatic sea, representing a well known basin type. Data have been analyzed through Independent Component Analysis, False Nearest Neighbours and the estimation of correlation dimension using Grasberger and Procaccia integral. Results show a clear non linear features in all the sites, characterized by second and third order Landau mode.
STROMBOLIAN-LIKE VOLCANO ACTIVITY: A COMMON MACROSCOPIC BEHAVIOUR
Authors: DE LAURO E. , DE MARTINO S. , FALANGA M. , PALO M. , SCARPA R.
Published: December 2009

We report the results of the analysis of the occurrence times of the strombolian-like explosions at Stromboli (Italy) and Erebus volcano (Antarctica). The distribution of the inter-times between successive explosion-quakes is exponential for both volcanoes, the only difference being the occurrence rate. It suggests that the signature of the standard Strombolian activity can be identified in a Poissonian process that rules the mechanism of generation of the explosions. Finally, we adopt coalescence Chandrasekar-Landau mean-field model for the formation of the exploding gas bubbles. The model provides a size distribution that is in a good agreement with the observed bubble dimensions.
MODELS OF EARTHQUAKE FAULTS: ERGODICITY AND FORECASTING
Authors: KLEIN W. , XIA J. , FERGUSON C. D. , GOULD H. , TIAMPO K. F. , RUNDLE J. B.
Published: December 2009

We discuss models of earthquake faults and earthquake fault systems and what they tell us about real earthquake faults. We concentrate on the question of whether models and real earthquake fault systems are in equilibrium and whether the system being in equilibrium affects the accuracy of forecasting algorithms.
THE GENERALIZED OMORI LAW: MAGNITUDE INCOMPLETENESS OR MAGNITUDE CLUSTERING
Authors: BOTTIGLIERI MILENA , DE ARCANGELIS LUCILLA , GODANO CATALDO , LIPPIELLO EUGENIO
Published: December 2009

The investigate the aftershock decay soon after the largest ten sequences occurred in Southern California in last 20 years. We show that this decay becomes independent on the mainshock magnitude MMand on the lower magnitude threshold MIif time is rescaled by an appropriate time scale fixed by the difference MM– MI. This result supports the idea that the missing of recorded earthquakes in first part of aftershock sequences is not an artefact due to catalog incompleteness but a real physical effect. We show that a recently proposed dynamical scaling relationship can reproduce the aftershock decay experimentally observed. This approach gives prediction also in agreement with recent results for the organization of aftershocks after small or intermediate magnitude mainshock in Japan.
TENSOR LOCALITY SENSITIVE DISCRIMINANT ANALYSIS AND ITS COMPLEXITY
Authors: WEI YANTAO , LI HONG , LI LUOQING
Published: December 2009

Feature extraction is one of the most challenging problems in pattern recognition fields and has attracted great attention recently. In this paper, we propose a novel feature extraction algorithm named tensor locality sensitive discriminant analysis which accepts tensors as inputs. The algorithm preserves the key structure of data by using the labeled samples and has high performance as well as low time complexity. Experiments on the three standard databases show that the proposed method has better performance and achieves high accuracy.
THE COMPLETE ASYMPTOTIC EXPANSIONS FOR THE SZÁSZ–MIRAKIAN-TYPE OPERATORS
Authors: ZHANG CHUNGOU , WANG QUAN-E
Published: December 2009

This paper is devoted to exploring asymptotic behavior of the Szász–Mirakian-type operators including the Szász–Mirakian operators Sn(f;x) and its two kinds of integral modifications [Formula: see text], [Formula: see text]. For these operators, we obtain the complete asymptotic expansions in the form of [Formula: see text] all coefficients ak (f;x) of n-k (k=1,2,…) are calculated explicitly in terms of the Stirling numbers of the first and second kind.
EXPLORING THE PROTEIN LANDSCAPE IN RAMACHANDRAN SPACE: IT'S NOT JUST PSI-PHI
Authors: KRIVAN WILLIAM , CARTER DARRICK
Published: December 2009

Most methods for the structural comparison of proteins utilize molecular coordinates in the three-dimensional physical space. Recently, a group has presented an elegant novel approach based on the characterization of protein shape in terms of backbone torsion angles. They have demonstrated considerable success in direct comparisons with other techniques, and their method lends itself to rapid screening of structural information from rapidly growing databases. We think that the torsion angle approach can be further strengthened by refining the distance notion that forms the basis of the computational scheme. In particular, we are suggesting to compute the distance along the path that minimizes the transition cost between aligned pairs of angles and therefore likely provides a more meaningful representation of distances between points in Ramachandran space.
Continuity mapping for multi-chart textures
Authors: González Francisco , Patow Gustavo
Published: December 2009

It is well known that multi-chart parameterizations introduce seams over meshes, causing serious problems for applications like texture filtering, relief mapping and simulations in the texture domain. Here we present two techniques, collectively known as
Continuity Mapping
, that together make any multi-chart parameterization seamless:
Traveler's Map
is used for solving the spatial discontinuities of multi-chart parameterizations in texture space thanks to a bidirectional mapping between areas outside the charts and the corresponding areas inside; and
Sewing the Seams
addresses the sampling mismatch at chart boundaries using a set of stitching triangles that are not true geometry, but merely evaluated on a perfragment basis to perform consistent linear interpolation between non-adjacent texel values.
Continuity Mapping
does
not
require any modification of the artist-provided textures or models, it is fully automatic, and achieves continuity with small memory and computational costs.
All-frequency rendering of dynamic, spatially-varying reflectance
Authors: Wang Jiaping , Ren Peiran , Gong Minmin , Snyder John , Guo Baining
Published: December 2009

We describe a technique for real-time rendering of dynamic, spatially-varying BRDFs in static scenes with all-frequency shadows from environmental and point lights. The 6D SVBRDF is represented with a general microfacet model and spherical lobes fit to its 4D spatially-varying normal distribution function (SVNDF). A sum of spherical Gaussians (SGs) provides an accurate approximation with a small number of lobes. Parametric BRDFs are fit on-the-fly using simple analytic expressions; measured BRDFs are fit as a preprocess using nonlinear optimization. Our BRDF representation is compact, allows detailed textures, is closed under products and rotations, and supports reflectance of arbitrarily high specularity. At run-time, SGs representing the NDF are warped to align the half-angle vector to the lighting direction and multiplied by the microfacet shadowing and Fresnel factors. This yields the relevant 2D view slice on-the-fly at each pixel, still represented in the SG basis. We account for macro-scale shadowing using a new, nonlinear visibility representation based on spherical signed distance functions (SSDFs). SSDFs allow per-pixel interpolation of high-frequency visibility without ghosting and can be multiplied by the BRDF and lighting efficiently on the GPU.
On evolutionary spectral clustering
Authors: Chi Yun , Song Xiaodan , Zhou Dengyong , Hino Koji , Tseng Belle L.
Published: December 2009

Evolutionary clustering is an emerging research area essential to important applications such as clustering dynamic Web and blog contents and clustering data streams. In evolutionary clustering, a good clustering result should fit the current data well, while simultaneously not deviate too dramatically from the recent history. To fulfill this dual purpose, a measure of
temporal smoothness
is integrated in the overall measure of clustering quality. In this article, we propose two frameworks that incorporate temporal smoothness in evolutionary spectral clustering. For both frameworks, we start with intuitions gained from the well-known
k
-means clustering problem, and then propose and solve corresponding cost functions for the evolutionary spectral clustering problems. Our solutions to the evolutionary spectral clustering problems provide more stable and consistent clustering results that are less sensitive to short-term noises while at the same time are adaptive to long-term cluster drifts. Furthermore, we demonstrate that our methods provide the optimal solutions to the relaxed versions of the corresponding evolutionary
k
-means clustering problems. Performance experiments over a number of real and synthetic data sets illustrate our evolutionary spectral clustering methods provide more robust clustering results that are not sensitive to noise and can adapt to data drifts.
Privacy challenges and solutions in the social web
Authors: Loukides Grigorios , Gkoulalas-Divanis Aris
Published: December 2009

Research related to online social networks has addressed a number of important problems related to the storage, retrieval, and management of social network data. However, privacy concerns stemming from the use of social networks, or the dissemination of social network data, have largely been ignored. And with more than 250 million active Facebook (http://facebook.com) users, nearly half of whom log in at least once per day [5], these concerns can't remain unaddressed for long.
Love in the Fourth Dimension
Authors: Berscheid Ellen
Published: December 2009

Psychologists' efforts to understand love began in the mid-twentieth century. The fact that they continue apace in the twenty-first century reflects increased awareness of the importance of love to understanding relationship phenomena and acknowledgment that an understanding of love has yet to be achieved. This article (a) describes one source of increased recognition that the present confusions surrounding love must be transcended if progress is to be made in understanding many relationship phenomena; (b) discusses the failure to explicate the love construct, which constitutes the major obstacle to the study of love phenomena; (c) discusses the need for a temporal model of love in relationships; and (d) suggests that it is important to consider the presence or absence of four types of love, each of which appears to be associated with different causal conditions and thus is likely to have a different temporal course as an adult relationship moves through time.
Creativity
Authors: Hennessey Beth A. , Amabile Teresa M.
Published: December 2009

The psychological study of creativity is essential to human progress. If strides are to be made in the sciences, humanities, and arts, we must arrive at a far more detailed understanding of the creative process, its antecedents, and its inhibitors. This review, encompassing most subspecialties in the study of creativity and focusing on twenty-first-century literature, reveals both a growing interest in creativity among psychologists and a growing fragmentation in the field. To be sure, research into the psychology of creativity has grown theoretically and methodologically sophisticated, and researchers have made important contributions from an ever-expanding variety of disciplines. But this expansion has not come without a price. Investigators in one subfield often seem unaware of advances in another. Deeper understanding requires more interdisciplinary research, based on a systems view of creativity that recognizes a variety of interrelated forces operating at multiple levels.
Social and Emotional Aging
Authors: Charles Susan T. , Carstensen Laura L.
Published: December 2009

The past several decades have witnessed unidimensional decline models of aging give way to life-span developmental models that consider how specific processes and strategies facilitate adaptive aging. In part, this shift was provoked by the stark contrast between findings that clearly demonstrate decreased biological, physiological, and cognitive capacity and those suggesting that people are generally satisfied in old age and experience relatively high levels of emotional well-being. In recent years, this supposed “paradox” of aging has been reconciled through careful theoretical analysis and empirical investigation. Viewing aging as adaptation sheds light on resilience, well-being, and emotional distress across adulthood.
Cognitive Neural Prosthetics
Authors: Andersen Richard A. , Hwang Eun Jung , Mulliken Grant H.
Published: December 2009

The cognitive neural prosthetic (CNP) is a very versatile method for assisting paralyzed patients and patients with amputations. The CNP records the cognitive state of the subject, rather than signals strictly related to motor execution or sensation. We review a number of high-level cortical signals and their application for CNPs, including intention, motor imagery, decision making, forward estimation, executive function, attention, learning, and multi-effector movement planning. CNPs are defined by the cognitive function they extract, not the cortical region from which the signals are recorded. However, some cortical areas may be better than others for particular applications. Signals can also be extracted in parallel from multiple cortical areas using multiple implants, which in many circumstances can increase the range of applications of CNPs. The CNP approach relies on scientific understanding of the neural processes involved in cognition, and many of the decoding algorithms it uses also have parallels to underlying neural circuit functions.
Hippocampal-Neocortical Interactions in Memory Formation, Consolidation, and Reconsolidation
Authors: Wang Szu-Han , Morris Richard G.M.
Published: December 2009

This review, focusing on work using animals, updates a theoretical approach whose aim is to translate neuropsychological ideas about the psychological and anatomical organization of memory into the neurobiological domain. It is suggested that episodic-like memory consists of both automatic and controlled components, with the medial temporal mediation of memory encoding including neurobiological mechanisms that are primarily automatic or incidental. These ideas, in the cognitive and behavioral domain, are linked to neurophysiological ideas about cellular consolidation concerning synaptic potentiation, particularly the relationship between protein synthesis-dependent long-term changes and shorter-lasting post-translational mechanisms. Ideas from psychology about mental schemas are considered in relation to the phenomenon of systems consolidation and, specifically, about how prior knowledge can alter the rate at which consolidation occurs. Finally, the hippocampal-neocortical interactions theory is updated in relation to reconsolidation, a process that enables updating of stored memory traces in response to novelty.
The Role of the Hippocampus in Prediction and Imagination
Authors: Buckner Randy L.
Published: December 2009

Traditionally, the hippocampal system has been studied in relation to the goal of retrieving memories about the past. Recent work in humans and rodents suggests that the hippocampal system may be better understood as a system that facilitates predictions about upcoming events. The hippocampus and associated cortical structures are active when people envision future events, and damage that includes the hippocampal region impairs this ability. In rats, hippocampal ensembles preplay and replay event sequences in the absence of overt behavior. If strung together in novel combinations, these sequences could provide the neural building blocks for simulating upcoming events during decision-making, planning, and when imagining novel scenarios. Moreover, in both humans and rodents, the hippocampal system is spontaneously active during task-free epochs and sleep, further suggesting that the system may use idle moments to derive new representations that set the context for future behaviors.