bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complexes of tryptophan dipeptides with the R2Sn(IV)2+ ion (R=Me, Ph): Spectroscopic studies, solution properties and structural implications
Authors: Girasolo M. A. , Guli G. , Pellerito L. , Stocco G. C. 
Published: January 2005

AbstractTryptophan dipeptides such as L‐tryptophyl‐L‐alanine (H2TrpAla), L‐tryptophyl‐L‐tyrosine (H2TrpTyr), L‐tryptophyl‐L‐tryptophan (H2TrpTrp), along with L‐histidyl‐L‐tyrosine (H2HisTyr), were reacted with R2SnO (R = Me, Ph) yielding the corresponding complexes. The complexes have been characterized by IR and 119Sn Mössbauer spectroscopy in the solid state and by 1H and 13C NMR in CD3OD solutions.Monomeric species were detected, with the tin atom arranged in a pentacoordinated trigonal‐bipyramidal structure. The dipeptides are coordinated via the terminal amino group, deprotonated peptide nitrogen and terminal carboxylate group.No side‐chain appears to be involved in bonding. Determination of rotamer populations for selected compounds was accomplished by vicinal coupling constant analysis and side‐chain orientations are interpreted. In this connection, the potential applications of these compounds as drugs is discussed.
Detection of intermediates in grignard reaction on the magnesium surface
Authors: Egorov Anatoly M. , Anisimov Alexander V. 
Published: January 2005

AbstractBenzyl radicals and ion‐radical pairs have been detected on a magnesium surface by electron spin resonance (ESR) spectroscopy during benzyl halide reactions with magnesium at low temperatures. The ratio of these intermediates depends on the carbon‐halogen bond energy in the starting benzyl halide, the nature of the magnesium surface and the degree of magnesium aggregation. Polymagnesiumbenzyl chlorides were formed in small amounts and only monomagnesium organic compounds were formed from benzyl bromide and benzyl iodide.
Photoaccelerated synthesis of 2‐vinylpyridines from unsaturated nitriles and ethyne
Authors: Karabet Francois , Heller Barbara , Kortus Karin , Oehme Günther 
Published: January 2005

AbstractThe heterocyclization of unsaturated nitriles and ethyne catalyzed by cyclopentadienyl‐1,5‐cis,cis‐cyclooctadiene‐cobalt(I) and promoted by light has been studied in toluene as solvent. Acrylonitrile and substituted acrylonitriles gave results of interest in the preparation of 2‐vinylpyridines. No reaction could be observed using fumaronitrile, maleonitrile or allyl cyanide.The (E)/(Z)‐ratio of educts and products seems to be not influenced by conditions in the reaction.
Chemical vapour deposition of germanium‐containing films by IR laser‐induced decomposition of ethoxy(trimethyl)germane
Authors: Fajgar Radek , Bastl ZdeněK , Tláskal Jaroslav , Pola Josef 
Published: January 2005

AbstractCarbon Dioxide (CO2) laser‐induced decomposition of ethoxy(trimethyl)germane (ETG) results in a substantial stripping of organic substituents from germanium and leads to deposition of organogermanium films, the composition of which is dependent on the mode of laser irradiation. Direct absorption of laser radiation in ETG affords material rich in Germanium, while a sulfur hexafluoride (SF6)‐photosensitized process produces a deposit composed of Germanium, Carbon, Hydrogen and Oxygen. The deposited materials can be modified by chemical reactions with acetic anhydride and atmospheric moisture.
Synthesis, characterization and fungicidal activity of triphenyltin derivatives of sarcosine: Crystal structures of [Ph3Sn(OCOCH2NH2CH3)2]Cl and [Ph3Sn(OCOCH2NH2CH3)2]NCS
Authors: Khoo Lian Ee , Goh Ngoh Khang , Eng George , Whalen Deborah J. , Hazell Alan 
Published: January 2005

AbstractTwo new sarcosine triphenyltin complexes formulated as [Ph3Sn(OCOCH2NH2CH3)2]X (XCl, NCS) were prepared and characterized via IR, proton NMR and Mössbauer spectroscopies, and their fungicidal properties againstCeratocystis ulmiwere determined. The crystal structures of bis(methylammonioacetato)triphenyltin chloride and isothiocyanate are also reported.
Effects of maternal deprivation and incubator rearing on adrenocortical activity in the adult rat
Authors: Thoman Evelyn B. , Levine Seymour , Arnold William J. 
Published: January 2005

AbstractRats were reared during the first 3 weeks of life in a group or singly, with the mother rat or in an incubator with no maternal contact. Variations in early experience were assessed in terms of adrenal steroid functioning when the animals were 1‐yr old. Whether they were reared in a group or individually, incubator‐reared animals were found to have significantly higher basal and stress levels of plasma corticosterone. In addition, their corticosterone response to stress was greater regardless of initial levels.
Effect of LSD on the sleep cycle of the developing kitten
Authors: Shimizu Akira , Himwich Harold E. 
Published: January 2005

AbstractThe effects of LSD on the sleep cycle were studied in 44 kittens during the growth period of 1 to 28 days of age. Electroencephalograms, electromyograms of the posterior neck muscles, and the respiratory rhythm were recorded and gross behavior was observed. With 10 μg/kg of d‐lysergic acid diethylamide, the per cent time of activated sleep in total sleeping time was diminished. This diminution was less marked in kittens 6 to 8 days of age or younger and became more significant in the kittens 11 to 13 days or older. With 20 μg/kg the decrease of per cent time of activated sleep was highly significant at all ages. With a larger dose, the influence of age could no longer be demonstrated. The duration of single episodes of activated sleep showed some evidence of shortening, but this effect was also not related to age.
Sleep ontogenesis in early human prematurity from 24 to 27 weeks of conceptional age
Authors: Dreyfus‐Brisac C. 
Published: January 2005

AbstractThe spontaneous behavior of 5 previable human prematures born between 24 and 27 weeks of gestational age and weighing between 600 and 900 g was studied, between the 3rd and 30th hr of life. Death occurred between the 28th and 120th hr. Body motility, eye movements, respiratory and cardiac rhythms, chin myogram, electroencephalogram (EEG), and crying were evaluated by careful observation and by polygraphic recordings for periods of from 1 to 2 hr. A very rich and continuous motility is described consisting of rapid jerks, either diffuse or localized, and of slow movements. Rhythmic movements of the chin or peribuccal area occur in bursts and are particularly striking. The paucity of rapid eye movements (REM) is also remarkable. The EEG is composed of silent periods interrupted by discontinuous polymorphic activity. The fixation of the cardiac rate, the absence of periodic respiration and of apneic periods are the most important vegetative phenomena. Crying occurs in short periods rarely lasting more than 20 sec. The state of these previable prematures cannot be considered as waking; it seems to be a very immature state of sleep that differs from both the quiet and the active sleep of full‐term newborns. This atypical sleep, which appears to be present in other species characterized by a great degree of immaturity at birth, does not give any evidence of cyclic organization.
Is heart rate an indicator of imprinted preferences and affect?
Authors: Klopfer Peter H. 
Published: January 2005

AbstractDifferent tests for “imprinted” preferences may produce discordant results. To resolve this enigma, measurements of changes in heart rate were recorded in the presence of the familiar imprinted and an unfamiliar object. The character of the changes in cardiac activity varied in an apparently haphazard fashion, nor did constraints on locomotion alter this picture. It is not known whether these considerable and seemingly spontaneous changes in cardiac activity are common to the young of all birds, or unique to ducklings. The underlying causes and their biological significance may pose a problem of greater importance than the presumed (and still unproven) relation between imprinting, heart rate, and affect.
Prenatal administration of reserpine: Effect upon hatching, behavior, and brainstem catecholamines of the young chick
Authors: Sparber S. B. , Shideman F. E. 
Published: January 2005

AbstractAn avian species (the domestic chicken) was used in an attempt to determine the effects of reserpine upon the developing embryo and newly hatched chicken. When reserpine was injected into the yolk sac of the fertilized egg prior to incubation, there was a decrease in hatchability which was log‐linearly related to the dose of reserpine; the older the embryo at the time reserpine was injected, the less the effect on hatchability. In addition to increasing mortality, reserpine caused a delay in hatching which was also dose dependent. During the first 7 days of incubation, injection of reserpine into the egg in a dose (0.1 mg/kg of egg) that did not appreciably affect hatching significantly decreased following in an imprinting situation. The same dose of reserpine given to older (15‐day‐old) embryos caused a significant increase in following. Week‐old chicks hatched from eggs injected with the drug prior to incubation exhibited a significant decrease in catecholamines (norepinephrine and epinephrine) in the brainstem, and significantly fewer avoidance responses in a conditioned escape/avoidance situation.
Genetic‐environmental interaction in “intelligence”: II. Models of behavior, components of variance, and research strategy
Authors: Harrington Gordon M. 
Published: January 2005

AbstractA taxonomy of types of models of behavior is developed within the framework of statistical design concepts. The advantages and limitations of each are discussed. Components of variance from a previous study are derived for different models. It is shown that, with appropriate models, predictive proportions of variances are substantially greater than are ordinarily reported in behavioral research. The position is taken that attention to genetic variables in behavioral research can yield major increases in information gained for the development of behavior theory; that genetic environmental interaction is of major significance in behavior though generally ignored by both geneticists and psychologists; that variables apparently predictive only for a single genotype may provide clues to general behavioral predictors; and that fruitful interchange between geneticists and psychologists requires conceptual adjustments on both sides.
Detour learning in the chick: Effect of reserpine administered during embryonic development
Authors: Sparber S. B. , Shideman F. E. 
Published: January 2005

AbstractChicks hatched from eggs injected with reserpine prior to incubation showed impaired performance in detour learning between 7 and 17 days of age, although locomotor activity and brainstem catecholamine levels were not significantly different from controls at 18 days. Day‐old chicks injected with the same amount of drug showed no significant depletion of brainstem catecholamines 7 days later, supporting the possibility that behavioral effects were due to exposure to the drug during embryogenesis.
Ontogenesis of the states of sleep in rat, cat, and guinea pig during the first postnatal month
Authors: Jouvet‐Mounier Danièle , Astic Liliane , Lacote Daniel 
Published: January 2005

AbstractThe behavioral and polygraphic characteristics of wakefulness and sleep were studied in 20 infant rats, 26 kittens, and 25 infant guinea pigs during their first month of postnatal life. In the infant guinea pig, the electrocorticographic (ECoG) patterns of sleep were similar to those of the adult, except for the absence of spindles during the first 3 weeks. In the rat and the cat, states of vigilance were not clearly differentiated in ECoG patterns during the first week; near the 8th day a fast, high amplitude ECoG appeared during paradoxical sleep (PS). The first signs of slow‐wave sleep (SWS) appeared at 11 to 13 days of age in the rat and at 15 to 21 days in the cat. The greater the immaturity of the animal at birth, the greater was the amount of time spent in PS in the perinatal period. In the rat, which was born the most immature, the decrease in the percent time of PS was very rapid: 70 % at birth, it decreased to 12% on the 30th day. In the cat the decrease was slower. In the guinea pig, despite its relative maturity, the percent time of PS at birth was 7%, approximately double that in the adult. The length of extrauterine life as well as the degree of immaturity at birth, played a role in the development of the sleep‐wakefulness cycle.
Influence of mode and duration of phenylalanine administration on biochemical parameters in rats of various ages
Authors: Yuwiler A. , Geller E. 
Published: January 2005

AbstractBlood and tissue levels of phenylalanine and tyrosine progressively increase during he first two weeks of feeding a phenylalanine‐rich diet to weanling rats. During the same time, liver phenylalanine hydroxylase activity and brain serotonin progressively decline. Hepatic tryptophan hydroxylase activity drops quickly to a constant, low level. With the exception of tryptophan hydroxylase, all of these parameters return towards normal upon continuous treatment. The magnitude of change varies with the age of the animal at initiation of dietary treatment and arises because of Differences in effective dosage and metabolism as the animals mature. A single phenylalanine injection produces a transient elevation in tissue phenylalanine levels without appreciably affecting brain serotonin. Repeated phenylalanine injections produce more marked alterations in tissue phenylalanine and tyrosine levels, lower activity of tryptophan hydroxylase, and increase serum adrenocorticoids; phenylalanine hydroxylase activity and brain serotonin levels are only marginally affected. These changes seriously complicate interpretations of time‐consuming behavioral studies in experimental PKU.
Selective priming of maternal responses by auditory and olfactory cues from mouse pups
Authors: Noirot Eliane 
Published: January 2005

AbstractPrevious data have shown that maternal behavior can be primed in mice by exposure to sound and smell from pups. This experiment shows that both types of cues act selectively on different maternal responses. Three groups of 20 naïve females were given an initial exposure respectively to both auditory and olfactory cues from pups, to auditory cues alone, or to olfactory cues alone. Their results during a subsequent standard test for maternal behaviour were then compared with those of 20 naïve control females, not previously exposed to cues from pups. The results favor the assumption of a selective priming process, olfactory cues exerting a positive effect on cleaning of pups, auditory cues exerting a positive effect on nest‐building.
Effects of prenatal administration of psychotropic drugs on behavior of developing rats
Authors: Clark Carol V. H. , Gorman Darrell , Vernadakis Antonia 
Published: January 2005

AbstractThe effects of prenatal administration of 1 mg/kg d‐amphetamine sulfate or 3 mg/kg chlorpromazine HCl to rats from days 12 through 15 of gestation inclusive were studied on behavior of the offspring in the open field, mazes, and operant conditioning. The locomotor activity scores of rats whose mothers received chlorpromazine were significantly lower than those of controls on day 13 after birth but reached a level significantly higher than that of controls on day 18. Offspring of amphetaminetreated mothers had relatively low activity scores early in testing and were delayed in reaching adult activity levels. Although in the mother‐goal‐maze offspring of both chlorpromazine‐ and amphetamine‐treated mothers generally had shorter latencies than controls, rats whose mothers received chlorpromazine made significantly more errors. These animals also took significantly longer to acquire the bar‐press response. No differences among groups were observed in learning or reversal in the T‐maze or in performance or extinction of the operant response.
The influence of nutrition on neural and behavioral development. I. Critical review of some data on the growth of the body and the brain following dietary deprivation during gestation and lactation
Authors: Altman Joseph , Das Gopal D. , Sudarshan Kiran 
Published: January 2005

AbstractThe scanty data available on the effects of undernutrition during gestation and lactation upon neural development in man are reviewed briefly. This review is followed by a description of the various techniques that have been employed for the experimental undernutrition of laboratory animals. Then a detailed review is given of the effects of dietary deprivation during gestation, lactation, after weaning, and in adulthood upon the development of the nervous system and its different parts in a variety of mammalian species, with special emphasis on the rat. Finally, in a programmatic statement, the developmental phases during which undernutrition can be produced experimentally are related to critical stages or vulnerable periods of brain development.
Familiar social and nonsocial stimuli and the kitten's response to a strange environment
Authors: Rheingold Harriet L. , Eckerman Carol O. 
Published: January 2005

AbstractThe effectiveness of the mother, a littermate, and the home environment were compared in alleviating the distress shown by kittens which had previously been placed alone in a strange environment. Tests were conducted on the same kittens at 2, 4, 6, and 8 weeks of age. In the intact group of mother and kittens in the home environment scarcely any cries were heard. But when the kittens were placed alone in the strange environment, the frequency of cries was greatly increased. When the mother or a littermate was present, however, the frequency of cries was reliably reduced. In contrast, when kittens were placed alone in the home environment, the frequency of cries was not reliably reduced. Although the frequency of cries decreased as the kittens grew older, the relative effectiveness of the mother's or littermate's presence in reducing the frequency increased with age, whereas the home environment did not reliably reduce the frequency at any age. These findings indicate that separation from accustomed companions was a more powerful cause of distress than separation from accustomed physical surroundings, and that being alone in familiar as well as strange settings can evoke distress in the young cat.
The influence of nutrition on neural and behavioral development: III. Development of some motor, particularly locomotor patterns during infancy
Authors: Altman Joseph , Sudarshan Kiran , Das Gopal D. , McCormick Nancy , Barnes David 
Published: January 2005

AbstractThe locomotor development of infant rats nursed by mothers that had free access to food during lactation or were fed during that period 40% or 20% of the ad lib diet were compared. The “spontaneous” emergence or disappearance of several locomotor patterns were sampled daily in an open field situation, and the development of others was studied by inducing them in test situations. The spontaneous motor patterns included general locomotor activity, pivoting, head lifting, and standing on the hindlegs. The induced activities were hanging and moving on a suspended horizontal string, clinging to and descending on vertical ropes, climbing up on a rod, and homing in various test situations. The motor performance of the severely undernourished animals (offspring of mothers on a 20% diet) was inferior to normals in all the observations. This was manifested most commonly in reduced frequency or speed in the performance of certain acts, and in some cases in the prolonged persistence of infantile motor patterns or a delay in the appearance of more advanced patterns.
Environmental influences on brain and behavior of year‐old rats
Authors: Riege Walter H. 
Published: January 2005

AbstractThe brains of rats, almost a year old, were found to be similarly susceptible to the influences of differential housing as had been those of weanling rats. In 3 experiments, male S1 rats, about 285 days of age, remained for 30, 60, or 90 days in enriched (EC), impoverished (IC), or standard colony (SC) conditions before sacrifice for measures of weights and enzymatic activities of standardized brain sections. Occipital and total cortical brain weights increased significantly after EC, whereas subcortical regions seemed to be resistant to environmental influences. Year‐old rats responded with greater cortical weight increases and enhanced occipital cholinesterase activities from a period of enrichment extended beyond 60 days than SC agemates. The cortices of IC rats, in contrast, showed a decline in weights with longer duration in isolation. Environmental enrichment, furthermore, disposed year‐old rats to faster learning in the Lashley III maze.
Effects of early tactile enrichment on open field activity and tactile discriminative ability in the rat
Authors: Finger Stanley , Fox M. W. 
Published: January 2005

AbstractTwenty‐eight blinded rats reared from 24 days of age under enriched and control tactile environmental conditions were examined at 90 days for the ability to discriminate between surfaces inscribed with different tactile features, and for exploratory activity in an open field. The 2 groups failed to differ on any of the 5 tactile discriminative problems, although open‐field scores revealed differences in exploration. These findings are discussed in relation to the effects of early experience on emotionality and learning ability.
Developmental environment: Variables important for later learning and changes in cholinergic activity
Authors: Brown Cathryn P. , King M. G. 
Published: January 2005

AbstractEnvironmental experience of developing rats was manipulated in two ways. These were (1) providing increments in amount of visual stimulation vs. increased variety of novelty of visual stimulation, and (2) informal experience vs. formal training in discriminating between the given stimuli. At the conclusion of the developmental treatment an index of performance change was obtained by testing discrimination learning on a Lashley Jumping Stand. Effects on the cholinergic system, specifically, acetylcholinesterase (AChE) and cholinesterase (ChE) activities, were also examined. Increments in variety of stimulation, but not increases in amount, were found to contribute significantly to observed differences in AChE and ChE activity and in learning performance. Formal training in addition to enriched informal experience added little to either the biochemical effects or to the observed improvement in performance on the relevant learning task.
Development of a fatted male phenomenon in California sea lions
Authors: Schusterman Ronald J. , Gentry Roger L. 
Published: January 2005

AbstractA captive colony of male sea lions (Zalophus californianus) living in northern California shows an annual weight fluctuation related to their reproductive season. Seasonal fattening, which is associated with an increase in territorial displays, starts developing at 5 years of age, when a sagittal crest first becomes apparent, and becomes more prominent as the males reach full maturity.
Differences in the mother‐infant relations of squirrel monkeys housed in social and restricted environments
Authors: Kaplan Joel 
Published: January 2005

AbstractMother and infant squirrel monkeys were housed together in either a group or a restricted environment until the infants were approximately 22 weeks of age. Observations of the mothers' and infants' behavior during this period revealed clear differences between the rearing conditions. Mothers in the socially restricted environment avoided and punished their infants more and were generally less protective than those in the group environment. However, these differences did not appear to reflect differences in maternal attitudes per se, but rather the extent to which infants in the two environments engaged in certain activities. Infants in the restricted environment attempted to play with their mother more often and remained closer to her as they became older.