bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogeny of amicable social behavior in the mouse: Gender differences and ongoing isolation outcomes
Authors: Terranova M. Livia , Laviola Giovanni , Alleva Enrico 
Published: January 2005

AbstractThe behavioral repertoire of male and female outbred CD‐1 mice was characterized during development (postnatal Days 23–47). To assess the effects of the rearing condition, half of the subjects were individually housed (IC) at weaning (Day 21), while the remaining mice were housed in pairs (PC) of same‐sex siblings. The occurrence of 22 behavioral items was scored during nine social encounters, 3 days apart, between pairs of unfamiliar same‐sex and same‐condition animals. Individually housed mice were much more involved than paired subjects in solitary play and social interactions (affilitive, investigative, and soliciting behaviors), while less interested in nonsocial behaviors (exploration, and escape‐oriented or maintenance activities). An over‐days increment for elements of social behavior was evident, with a peak of affiliative behavior at 23–32 days of age. For gender differences, in contrast with rat data, a marked female primacy in both social and playful behaviors was found. Overall, these findings clearly indicate that the behavioral repertoire of developing mice during paired encounters is strongly affected by both the sex of the subjects and the housing condition they are experiencing. © 1993 John Wiley & Sons Inc.
Repeated exposure of rat pups to isolation attenuates isolation‐induced ultrasonic vocalization rates: Reversal with naltrexone
Authors: Goodwin Gregory A. , Molina Victor A. , Spear Linda P. 
Published: January 2005

AbstractYoung rat pups are dependent on the dam for their survival, thus isolation of the neonatal rat pup from the dam presents the young organism with a variety of stressors. The question examined in this study concerns the ability of the young rat pup to modify its response to isolation following repeated exposure to that isolation as well as the role played by endogenous opiates in this process. Following repeated isolations, pups were seen to decrease vocalization rates. Altering the context in an attempt to dishabituate animals failed to reverse the decreased vocalization rate. However, opiate receptor blockade attenuated this decrease when administered subsequent to the first isolation period but not prior to the last isolation period. These results suggest that the development of this attenuated response to isolation stress is opiate‐mediated but that once established, its expression is not dependent on endogenous opiate release.© 1994 John Wiley & Sons, Inc.
Infant salt taste: Developmental, methodological, and contextual factors
Authors: Beauchamp Gary K. , Cowart Beverly J. , Mennella Julie A. , Marsh Roger R. 
Published: January 2005

AbstractTwo studies investigated the human infant's response to salt during development. In the first study, measures of intake and sucking were obtained from two groups of infants, newborns and 4‐ to 8‐month‐olds, in response to brief presentations of two concentrations of salt (0.2 or 0.4 M) and water. For several measures of sucking and for intake, there were significant age and concentration effects. Generally, newborn infants tended to reject saline relative to water more than did 4‐ to 8‐month‐old infants. This result, consistent with previously published research, suggests a developmental change in salt acceptability and, probably, sensitivity in the human infant. In the second longitudinal study, the response to salted (0.15 M) versus unsalted formulas was evaluated monthly in infants 2 to 7 months of age. Again, a developmental change was observed: Based on some sucking measures, younger infants appeared to be indifferent to the salted formula relative to the unsalted formula whereas older infants tended to reject the salted formula, presumably because either it was less sweet than the unsalted formulas or because it was novel. These data are consistent with the hypothesis developed from animal model studies that during early human postnatal development, transductive elements sensitive to saltiness mature.©1994 John Wiley & Sons, Inc.
Ontogeny of the ionic specificity of sodium appetite in the rat pup
Authors: Leshem Micah , Neufeld Michal , Canho Sonia Del 
Published: January 2005

AbstractSodium‐deficient adult rats prefer NaCl to other monochloride salts (e.g., Denton, 1991; Schulkin, 1991). However, it is not known when or how this specificity develops. Our experiments charted the development of the ionic specificity of sodium appetite aroused by sodium depletion or intracerebroventricular injection of renin. We compared intake of 3% NaCl to three other monochlorides, potassium (K), ammonium (NH4), and lithium (Li), and calcium chloride (CaCl2) at various ages between 72 hr postnatal and weaning. This revealed a biphasic developmental scheme: The adult pattern of discrimination between the salts emerges between 3 and 18 days of age. Subsequently, the preference for Na over the other salts increases into adulthood.©1994 John Wiley & Sons, Inc.
Cocaine alters cyclic motor activity in the fetal rat
Authors: Simonik Diane K. , Robinson Scott R. , Smotherman William P. 
Published: January 2005

AbstractIndividual rat fetuses were exposed to cocaine by injection into the cisterna magna on E20 or E21 of gestation. On E20, cocaine elevated motor activity throughout the 20‐min session, with activity increasing to double SAL‐injected levels by the end of the session. On E21, overall activity also was elevated after cocaine, increasing four‐ to fivefold in the first 5 min of the session, and decreasing to twice the levels of SAL controls thereafter. Movement time series were subjected to spectral analysis to characterize cyclic motor organization. Cyclicity was evident in 67% of control and 97% of cocaine‐injected fetuses. Cocaine increased the number of peaks in the movement spectrum and resulted in greater spectral density at the primary frequency of cyclic movement. Prenatal exposure to cocaine may alter patterns of cyclicity in the fetus, with consequences for the normal development of attention and behavioral state in the neonate.©1994 John Wiley & Sons, Inc.
Potentiation of isolation‐induced vocalization by brief exposure of rat pups to maternal cues
Authors: Hofer Myron A. , Brunelli Susan A. , Shair Harry N. 
Published: January 2005

AbstractSince their discovery in 1956, the highest rates of ultrasonic vocalization (USV) have been recorded from infant rats when first isolated in an unfamiliar place. We now report that peak USV rates can be doubled by allowing test pups a brief initial period of contact with their anesthetized dam (1–10 min) in the test chamber before isolating the pup by her removal. Potentiation of the isolation response was specific to the dam, for it failed to occur following initial contact with a group of 4 warm, anesthetized littermates. Control experiments showed that potentiation could not be attributed to thermal contrast, experimenter handling, general behavioral activation, novelty of maternal cues, or nursing deprivation. Furthermore, it did not occur when pups were taken for isolation testing directly from prolonged contact with their anesthetized dam in the home cage. Potentiation may be understood in terms of the communicative role of the pups' call and/or prior learning contingencies within the mother–infant interaction.©1994 John Wiley & Sons, Inc.
Sound localization in newborn human infants
Authors: Morrongiello Barbara A. , Fenwick Kimberley D. , Hillier Loretta , Chance Graham 
Published: January 2005

AbstractNewborns' localization of sounds was examined in two experiments that utilized different psychophysical procedures and imposed different task demands. The results of both experiments were consistent in indicating that neonates not only differentiate the hemifield of a sound source but have some capacity to localize a sound within the hemifields. Adjustment of their initial head turn angle following a within‐hemifield shift in location of an ongoing sound indicated that head orientation in neonates is elicited not only by sound onset but also by changes in location of an ongoing sound. Thus, multiple stimulus parameters impact on this neonatal response. Results are related to research on sound localization in older infants, and discussed in light of early development of the central auditory system.©1994 John Wiley & Sons, Inc.
Developmental changes in the contextual control of recognition
Authors: Earley Linda A. , Bhatt Ramesh S. , Rovee‐Collier Carolyn 
Published: January 2005

AbstractIn three experiments, we explored potential developmental differences in the contextual control of target recognition using elementary perceptual features that differed only in their spatial relations. Three‐and 6‐month‐old infants were trained in the presence of black horizontal and vertical line segments arranged as Ls, Ts, or + s on a pink background and were tested in the presence of the same line segments in a different spatial arrangement. At both ages, target recognition required a match between the primitive perceptual features in the test context and those present during training. Delayed recognition by younger but not older infants also required a match between specific spatial arrangements of the horizontal and vertical segments (+ s versus Ls or Ts), despite the fact that infants of both ages had initially encoded these relations. These data suggest that by 6 months, spatial information in the periphery is detected preattentively via a parallel‐processing mechanism, as it is in children and adults. © 1995 John Wiley & Sons, Inc.
Dissociation of behavioral and neural correlates of early associative learning
Authors: Sullivan Regina M. , Wilson Donald A. 
Published: January 2005

AbstractWistar rat pups were trained in an olfactory associative conditioning task on postnatal Day 6, 12, or 20. The training consisted of 20 pairings of a novel odor (peppermint) with footshock (1.5 mA, 1 s) with an intertrial interval of 3 min. Additional pups were trained in either unpaired or naive control conditions. On the day following training, pups were either tested for their behavioral response to the conditioned odor in a two‐odor choice test, or injected with 14C‐2‐deoxyglucose and exposed to the odor for examination of olfactory bulb neural responses to the odor. The results demonstrate that, although pups at all ages learned to avoid the odor, only pups trained during the first postnatal week had a modified olfactory‐bulb glomerular‐layer response to the odor. These results suggest that although olfactory memory is correlated with modification of olfactory bulb glomerular layer function in newborns, these changes are not required for normal memory in older pups. © 1995 John Wiley & Sons, Inc.
Thermal expansion of Portland cement paste, mortar and concrete at high temperatures
Authors: Cruz C. R. , Gillen M. 
Published: December 2004

AbstractResults of measurements of thermal expansion of Portland cement paste, mortar, concrete and a dolomitic rock aggregate are presented. Test temperatures ranged from 27 to 871°C. Cement paste contracted when subjected to temperatures from 204 to 871°C. Thermal expansion of mortar and concrete was dominated by thermal expansion characteristics of the mineral aggregate. However, expansion was moderated by contraction of the cement paste matrix at elevated temperatures. Average coefficients of expansion, over specific temperature ranges, are given for the materials tested. Equipment developed to control automatically the rate of heating and record strain vs. temperature relationships is described.
The pyrolysis of organic nitriles
Authors: Metcalfe E. , Booth D. , McAndrew H. , Wooley W. D. 
Published: December 2004

AbstractDetailed quantitative studies are reported on the kinetics of acetonitrile pyrolysis using an isothermal quartz tubular flow reactor at 720–1033 K and 1 atm. Pressure using flow rates, in nitrogen, of 2–200 ml min−1. The pyrolysis of several other nitriles (acrylonitrile, propionitrile, methacrylonitrile and benzonitrile) has also been investigated qualitatively by pyrolysis‐gas chromatography.
Heat release and classification of fire retardant wood products
Authors: östman Birgit A.‐L. , Tsantaridis Lazarous D. 
Published: December 2004

AbstractA comparison is presented of cone calorimeter heat release data between fire retardant treated and untreated wood products. The test results show significant differences between these two groups. The parameters included in the comparison are time to ignition, rate of heat release (peak and average values) and total heat release. The wood‐based products were also tested in different small‐scale national standard fire tests and in the full‐scale room fire test. Fire retardant wood products achieve an improved classification both in present national systems and in possible new systems based on the cone calorimeter and the room fire test.
A comparison of binding properties and structure of NGF receptor on PC12 pheochromocytoma and A875 melanoma cells
Authors: Buxser Stephen E. , Watson Leslie , Johnson Gary L. 
Published: December 2004

AbstractRat PC12 pheochromocytoma and human A875 melanoma cells express nerve growth factor (NGF) receptors on their surfaces. Covalent crosslinking of bound 125I‐NGF to PC12 or A875 intact cells or plasma membrane‐enriched fractions resulted in labelling of a peptide doublet at Mr = 110,000 and a single labelled peptide at Mr = 200,000 for each of the cell and membrane preparations. However, a difference between equilibrium binding properties of NGF‐receptor on PC12 and A875 cells was observed. PC12 cells exhibited biphasic binding properties with two apparent binding sites: KD = 5.2 nM sites and KD = 0.3 nM sites. The high‐affinity PC12 binding sites were trypsin resistant, and 125I‐NGF dissociated slowly from them. A875 cells exhibited sites with homogeneous properties (KD = 1.0 nM), all binding sites were trypsin sensitive, and 125I‐NGF dissociated rapidly in the presence of unlabelled NGF. Membrane‐enriched fractions from either cell type contained binding sites with a uniform low affinity (KD = 3 nM) that were trypsin sensitive, and 125I‐NGF rapidly dissociated from them. Sixty to 80 percent of binding sites in membranes could be converted to the high‐affinity, trypsin‐resistant state by addition of wheat germ agglutinin (WGA). The loss of high‐affinity, trypsin‐resistant sites from PC12 cells during preparation of plasma membrane fractions does not appear to be the result of selective isolation of low‐affinity sites or proteolytic degradation since there is a loss of 125I‐NGF binding immediately after cell lysis which is not blocked by protease inhibitors. Also, high‐affinity, trypsin‐resistant binding sites are not found associated with other cell fractions. The differences between receptor properties on PC12 cells and on A875 cells apparently are the result of differences in the respective intracellular environments. Thus, significant structural homology exists between receptors on A875 and PC12 cells. Cell components other than the binding unit of the NGF receptor may be responsible for the different properties of receptor.
Characterization of isolates and clones of leishmania by analysis of kinetoplast DNA
Authors: Spithill Terry W. , Grumont Raelene J. , Mitchell Graham F. 
Published: December 2004

AbstractThe genetic characterization of pathogenic isolates of Leishmania was attempted by analysis of the molecular properties of kinetoplast DNA (kDNA) minicircles. Unit minicircle size is not conserved during speciation of Leishmania since the minicircles of strains and clones of L t major are smaller (700 bp) than those found in certain strains of L mexicana ssp (820 bp), L donovani (850 bp) or L t tropica (900 bp). Schizodeme analysis of minicircles reveals a high degree of sequence divergence in kDNA of Leishmania with the degree of microheterogeneity varying between species. This sequence divergence allows the discrimination of species, strains, and clones of Leishmania into schizodemes. Southern blot hybridization experiments reveal that at high stringency overall minicircle sequence homology is conserved among clones and strains of one species (L t major) but not between different species. This property of minicircle DNA permits the use of kDNA probes as a species‐specific diagnostic test for the identification of unknown Leishmania isolates. The properties of kDNA from an L t tropica strain LRC‐L32 (a “recidiva” organism) are so diverged from those of L t major strains as to support the classification [22,23] of L t tropica and L t major as separate species of Leishmania rather than subspecies of L tropica.
Characterization of a sheep pituitary‐derived growth factor for rat and human mammary tumor cells
Authors: Ikeda Tatsuhiko , Danielpour David , Sirbasku David A. 
Published: December 2004

AbstractA growth factor for rat and human mammary tumor cells (MTGF‐Pit) was isolated from lyophilized powders of whole sheep pituitaries by a rapid four‐step procedure utilizing acetic acid extraction, heating at 93°C, and sequential chromatography in 0.10 M acetic acid on sulphopropyl Sephadex and Sephadex G‐50. From 10 g of pituitary powder, 8‐10‐mg amounts of MTGF‐Pit were isolated. By 8 M urea, 0.1% SDS‐12.5% polyacrylamide gel electrophoresis analysis followed by Coomassie blue staining, this preparation was shown to be one major stained band. When assayed for growth effects on cells maintained in serum‐free medium, 5.1‐19.2 nM MTGF‐Pit half replaced the growth of MTW9/PL rat and MCF‐7 and T‐47D human mammary tumor cells in response to 2% to 10% serum. MTGF‐Pit shows mitogenic activity toward normal human diploid fibroblasts only at concentrations in excess of 2.5 × 10−4 M, while rat fibroblasts are unresponsive even at this high concentration. From data available, we conclude that a mitogenic activity for epithelial‐type mammary cells has been isolated, and this growth factor appears to be a previously undetected acid‐ and heat‐stable activity that is highly abundant (estimated at 0.16% or more of the total dry weight of the pituitary powder). The isolated ovine MTGF‐Pit (3,900 ± 200 daltons) does not share the molecular weight of native prolactin (24,000 daltons), “cleaved” prolactin (16,000 daltons), or growth hormone (22,000 daltons), and by all tests applied cannot be replaced with other known hormones and purified growth factors. We conclude a potent new mammary tumor cell mitogenic activity has been identified from sheep pituitaries.
Hepatocyte uptake of α1‐proteinase inhibitor‐trypsin complexes in vitro: Evidence for a shared uptake mechanism for proteinase complexes of α1‐proteinase inhibitor and antithrombin III
Authors: Fuchs Herbert E. , Michalopoulos George K. , Pizzo Salvatore V. 
Published: December 2004

AbstractIn vivo clearance studies have indicated that the clearance of proteinase complexes of the homologous serine proteinase inhibitors α1‐proteinase inhibitor and anti‐thrombin III occurs via a specific and saturable pathway located on hepatocytes. In vitro hepatocyte‐uptake studies with antithrombin III‐proteinase complexes confirmed the hepatocyte uptake and degradation of these complexes, and demonstrated the formation of a disulfide interchange product between the ligand and a cellular protein. We now report the results of in vitro hepatocyte uptake studies with α1‐proteinase inhibitor‐trypsin complexes. Trypsin complexes of α1‐proteinase inhibitor were prepared and purified to homogeneity. Uptake of these complexes by hepatocytes was time and concentration‐dependent. Competition experiments with α1‐proteinase inhibitor, α1‐proteinase inhibitor‐trypsin, and antithrombin III‐thrombin indicated that the proteinase complexes of these two inhibitors arc recognized by the same uptake mechanism, whereas the native inhibitor is not. Uptake studies were performed at 37°C with 125I‐α1‐proteinase inhibitor‐trypsin and analyzed by sodium dodecyl sulfate‐gel electrophoresis in conjunction with autoradiography. These studies demonstrated time‐dependent uptake and degradation of the ligand to low molecular weight peptides. In addition, there was a time‐dependent accumulation of a high molecular weight complex of ligand and a cellular protein. This complex disappeared when gels were performed under reducing conditions. The sole cysteine residue in α1‐proteinase inhibitor was reduced and alkylated with iodoacetamide. Trypsin complexes of the modified inhibitor were prepared and purified to homogeneity. Uptake and degradation studies demonstrated no differences in the results obtained with this modified complex as compared to unmodified α1‐proteinase inhibitor‐trypsin complex. In addition, the high molecular weight disulfide interchange product was still present on sodium dodecyl sulfate‐polyacrylamide gel electrophoresis of solubilized cells. Clearance and clearance competition studies with approteinase inhibitor‐trypsin, alkylated α1‐proteinase inhibitor‐trypsin, antithrombin III‐thrombin, and antithrombin III‐factor IXa further demonstrated the shared hepatocyte uptake mechanism for all these complexes.
Expression and assembly of the erythroid membrane‐skeletal proteins ankyrin (goblin) and spectrin in the morphogenesis of chicken neurons
Authors: Lazarides Elias , Nelson W. James 
Published: December 2004

AbstractThe membrane‐skeleton of adult chicken neurons in the cerebellum and optic system is composed of polypeptides structurally and functionally related to the erythroid proteins spectrin and ankyrin, respectively. Neuronal spectrin comprises two distinct complexes that share a common α subunit (Mr 240,000) but which have structurally distinct polymorphic subunits (β′β spectrin; Mr 220/225,000; γ spectrin, Mr 235,000): the brain‐specific form (αγ spectrin or fodrin) and an erythrocyte‐specific form (αβ′β spectrin). Two structurally related isoforms of ankyrin have also been identified and are termed α (Mr 260,000) and β (Mr 237,000) ankyrin. Immunofluorescence demonstrates that the variants of spectrin and ankyrin, respectively, have different distributions within neurons. On the one hand, αγ spectrin and β ankyrin are present throughout the neuron, in the perikaryon, dendrites and axon, whereas αβ′ spectrin and α ankyrin are localized exclusively in the perikaryon and dendrites where they are actively segregated from αγ spectrin and other components of axonal transport. This asymmetric distribution of spectrin and ankyrin isoforms is established in distinct stages during neuronal morphogenesis. Early in cerebellar and retinal development, αγ spectrin is expressed in mitotic cells. Subsequently β ankyrin and αγ spectrin are co‐expressed in postmitotic cells and gradually accumulate on the plasma membrane in a uniform pattern throughout the neuron during the phase of cell growth. At the onset of synaptogenesis and the cessation of cell growth, their levels of synthesis decline sharply while the assembled proteins remained as stable membrane components. Concomitantly, there is a dramatic induction in the accumulation of α ankyrin and αβ′ spectrin, whose assembly is limited to the plasma membrane of the perikarya and dendrites. These results demonstrate that two successive, developmentally regulated programs of ankyrin and spectrin expression and patterning on the plasma membrane are involved in the assembly of the spectrin‐based asymmetry in the neuronal membrane‐skeleton, and that their asymmetric distribution is actively maintained throughout the life of the neuron.