bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attachment and social preferences in cooperatively‐reared cotton‐top tamarins
Authors: Kostan Karen M. , Snowdon Charles T. 
Published: October 2002

AbstractIn many primate species a close attachment between mother and infant provides a secure base for the infant when the infant is frightened or under stress. In cooperatively breeding primates infant carrying is divided among several individuals in the group, with the mother often doing little more than nursing. In these species it is not clear which individual would best serve as a secure base for the infant. We studied eight infant cotton‐top tamarins from birth through 20 weeks of age, noting who carried the infant during the first 100 days, who transferred food with the infants, and, as infants became independent, with whom they associated during social play and affiliative behavior. From week 9 to week 20, when infants were independent of carriers most of the time, we presented families with six trials (once every 2 weeks) with a threatening stimulus (a human dressed in a lab coat and wearing an animal mask). Infants played primarily with their twin or youngest sibling and had affiliative interactions with many family members. However, in fearful situations, infants ran to those who had carried them and transferred food with them the most–their father or oldest brother (never to the mother). Although adults increased rates of mobbing calls in response to the threat, infants significantly reduced their vocalization rate. For these cooperatively breeding monkeys, the attachment object for infants is the family member that invested the most effort in carrying the infant and transferring food with the infant. These results parallel and extend results from bi‐parental infant care species in which the father serves as the primary attachment figure. © 2002 Wiley‐Liss, Inc.
Comparison of responses to alarm calls by patas (Erythrocebus patas) and vervet (Cercopithecus aethiops) monkeys in relation to habitat structure
Authors: Enstam Karin L. , Isbell Lynne A. 
Published: October 2002

AbstractWe studied responses to alarm calls of sympatric patas (Erythrocebus patas) and vervet (Cercopithecus aethiops) monkeys in relation to habitat structure, with the intention of understanding the relationship between the environment and predator avoidance. Patas and vervet monkeys are phylogenetically closely related and overlap in body size. However, while patas monkeys are restricted to nonriverine habitats at our study site, vervets use both nonriverine and riverine habitats, allowing us to “vary” habitat structure while controlling for effects of group size, composition, and phylogeny. Patas monkeys in the nonriverine habitat responded to mammalian predator alarm calls with a greater variety of responses than did vervets in the riverine habitat, but not when compared with vervets in the nonriverine habitat. Ecological measurements confirm subjective assessments that trees in the riverine habitat are significantly taller and occur at lower densities than trees in the nonriverine habitat. Despite the lower density of trees in the riverine habitat, locomotor behavior of focal animals indicates that canopy cover is significantly greater in the riverine than the nonriverine habitat. Differences in responses to alarm calls by the same groups of vervets in different habitat types, and convergence of vervets with patas in the same habitat type, suggest that habitat type can be a significant source of variation in antipredator behavior of primates. Am J Phys Anthropol 119:3–14, 2002. © 2002 Wiley‐Liss, Inc.
Creutzfeldt‐Jakob disease cluster in an Australian rural city
Authors: Collins Steven , Boyd Alison , Fletcher Ashley , Kaldor John , Hill Andrew , Farish Stephen , McLean Catriona , Ansari Zahid , Smith Margaret , Masters Colin L. 
Published: October 2002

AbstractThrough the Australian National Creutzfeldt‐Jakob Disease Registry, 6 pathologically confirmed sporadic cases were recognized over a 13‐year period in persons who had been long‐term residents of a moderate‐sized rural city, whereas the expected number was 0.923. An extensive investigation could not find any point‐source or case‐to‐case transmission links. This occurrence is highly statistically significant (p = 0.0027) when viewed in isolation and remains significant (p < 0.02) when only the cases that arose after the cluster was recognized were taken into account. However, a more conservative statistical analysis suggests that such a grouping could have arisen by chance in at least one population group of this size when the whole country is taken into consideration.
Acute hyperglycemia adversely affects stroke outcome: A magnetic resonance imaging and spectroscopy study
Authors: Parsons Mark W. , Barber P. Alan , Desmond Patricia M. , Baird Tracey A. , Darby David G. , Byrnes Graham , Tress Brian M. , Davis Stephen M. 
Published: October 2002

AbstractControversy exists whether acute hyperglycemia is causally associated with worse stroke outcome or simply reflects a more severe stroke. In reversible ischemia models, hyperglycemia is associated with lactic acidosis and conversion of penumbral tissue to infarction. However, the relationship between hyperglycemia, lactic acidosis, and stroke outcome has not been explored in humans. Sixty‐three acute stroke patients were prospectively evaluated with serial diffusion‐weighted and perfusion‐weighted magnetic resonance imaging and acute blood glucose measurements. Patients with hypoperfused at‐risk tissue were identified by acute perfusion‐diffusion lesion mismatch. As a substudy, acute and subacute magnetic resonance spectroscopy was performed in the 33 most recent patients to assess the relationship between acute blood glucose and lactate production in the ischemic region. In 40 of 63 patients with acute perfusion‐diffusion mismatch, acute hyperglycemia was correlated with reduced salvage of mismatch tissue from infarction, greater final infarct size, and worse functional outcome. These correlations were independent of baseline stroke severity, lesion size, and diabetic status. Furthermore, higher acute blood glucose in patients with perfusion‐diffusion mismatch was associated with greater acute‐subacute lactate production, which, in turn, was independently associated with reduced salvage of mismatch tissue. In contrast, acute blood glucose levels in nonmismatch patients did not independently correlate with outcome measures, nor was there any acute‐subacute increase in lactate in this group. Acute hyperglycemia increases brain lactate production and facilitates conversion of hypoperfused at‐risk tissue into infarction, which may adversely affect stroke outcome. These findings support the need for randomized controlled trials of aggressive glycemic control in acute stroke.
Magnetization transfer imaging in normal aging, mild cognitive impairment, and Alzheimer's disease
Authors: Van Der Flier Wiesje M. , Van Den Heuvel Dominique M. J. , Weverling‐Rijnsburger Annelies W. E. , Bollen Eduard L. E. M. , Westendorp Rudi G. J. , Van Buchem Mark A. , Middelkoop Huub A. M. 
Published: October 2002

AbstractThe purpose of this study was to assess whether structural brain damage as detected by volumetric magnetization transfer imaging (MTI) is present in mild cognitive impairment (MCI) and Alzheimer's disease (AD) and, if so, whether these abnormalities are global in character or restricted to the temporal lobe. Volumetric MTI analysis of the whole brain and temporal and frontal lobes was performed in 25 patients with probable AD, in 13 patients with MCI, and in 28 controls. Magnetization transfer ratio (MTR) histograms were produced, from which we derived measures for structural brain damage and atrophy. The peak heights of the MTR histograms of MCI and AD patients were lower than those of controls for the whole brain and temporal and frontal lobes, reflecting structural brain damage. AD patients had more atrophy than controls in all regions that were studied. MCI patients differed from controls for temporal lobe atrophy only. Volumetric MTI demonstrates structural changes that are related to cognitive decline in large parts of the brain of AD patients. Moreover, structural changes also were observed in MCI patients, indicating that widespread brain damage can be demonstrated before patients are clinically demented.
Comparative degradation data of polyesters and related poly(ester amide)s derived from 1,4‐butanediol, sebacic acid, and α‐amino acids
Authors: Montané J. , Armelin E. , Asín L. , Rodríguez‐Galán A. , Puiggalí J. 
Published: October 2002

AbstractTwo new sequential poly(ester amide)s (PEAs) derived from 1,4‐butanediol, sebacic acid, and L‐alanine (PABA8) or glycine (PGBG8) are prepared and characterized. For comparative purposes the related polyesters (PEs) 4,10 and 6,10 are also studied. The calorimetric analysis shows that the inclusion of amino acids improves the thermal properties such as the melting temperature without a significant reduction in their thermal stability. All polymers show hydrolytic and enzymatic degradability. The degradation rates of the PEAs are higher for the alanine derivative (PABA8) because of its low crystallinity and the higher specificity of the essayed proteolytic enzymes. The PEs are only degraded faster when enzymes with esterase activity are employed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1815–1824, 2002
Fourier transform infrared photoacoustic studies of the adsorption behavior of poly(2‐hydroxypropyl methacrylate) at solid–liquid interface
Authors: Pekel Nursel , Güven Olgun 
Published: October 2002

AbstractAdsorption of poly(2‐hydroxypropyl methacrylate) on alumina from dimethylformamide was studied by ultraviolet (UV) and Fourier transform infrared (FT‐IR) photoacoustic spectroscopy (FTIR PA) techniques. Adsorbent amount and concentration effects were investigated. The adsorption results are in conformity with Langmuir's isotherm. The differences observed in Langmuir parameters were explained by polymer–polymer, polymer–solvent, polymer–adsorbent, and solvent–adsorbent interactions. The fraction of carbonyl groups attached to the surface of alumina was calculated with a curve‐fitting computer program. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2750–2756, 2002
Flavin‐grafted poly(vinyl alcohol): Preparation and properties
Authors: Sanjust Enrico , Cocco Dina , Curreli Nicoletta , Rescigno Antonio , Sollai Francesca , Bannister Joe Victor 
Published: October 2002

AbstractAn NAD(P)H oxidase‐like activity was found in semisynthetic flavoadducts, prepared from an aldehyde derivative of riboflavin and commercial poly(vinylalcohol) (PVA), previously grafted with aminopropyl side chains. Both water‐soluble and water‐insoluble beaded preparations were obtained. The products showed a noticeable NAD(P)H oxidase‐like activity, converting the nucleotide substrate to its oxidized counterpart NAD(P)+ at the expense of molecular oxygen, the latter being reduced to hydrogen peroxide. In contrast to some “true” β‐NAD(P)H oxidases, the PVA adducts do not require the presence of additional flavin adenine dinucleotide (FAD) to work; some properties of the flavoadducts were studied that make these flavoadducts good candidates for technological applications. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2471–2477, 2002
Dynamically vulcanized nitrile rubber/polypropylene thermoplastic elastomers
Authors: Zhang Xiangfu , Huang Hua , Zhang Yinxi 
Published: October 2002

AbstractA new compatibilized method was used to prepare thermoplastic elastomer (TPE) of nitrile rubber (NBR) and polypropylene (PP) with excellent mechanical properties by dynamic vulcanization. Glycidyl methacrylate (GMA) grafted PP/amino‐compound was used as a compatibilizer. The effects of the curing systems, compatibilizer, PP type, and reprocessing on the mechanical properties of NBR/PP thermoplastic elastomers were investigated in detail. Experimental results showed that the addition of amino‐compound in the compatibilzer can significantly increase the mechanical properties of the NBR/PP thermoplastic elastomer. Compared with other amino‐compounds, diethylenetriamine (DETA) has the best effect. PP with higher molecular weight is more suitable for preparing NBR/PP thermoplastic elastomer with high tensile strength and high elongation at break. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2862–2866, 2002
Preparation and properties of poly(methyltrifluoropropylsiloxane‐b‐imide) copolymer. I
Authors: Kang Doo Whan , Kim Young Min 
Published: October 2002

AbstractPoly(methyltrifluoropropylsiloxane‐block‐imide) copolymers (PSBPI), containing various contents of fluorosiloxane, were prepared by the thermal imidization of 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA), 4,4′‐oxydianiline (ODA), and α,ω‐aminopropyl‐terminated poly(methyltrifluoropropylsiloxane) prepolymer (APMFS). APMFS was prepared from an equilibrium polymerization of (3,3,3‐trifluoropropyl)methylcyclotrisiloxane (D3Me,CH2,CH2,CF3) with 1,3‐bis(3‐aminopropyl)‐1,1,3,3‐tetramethyldisiloxane in the presence of the tetramethylammoniumhydroxide (TMAH) catalyst. The content of APMFS, in the reaction mixture, was varied from 0 to 30 wt % of diamine. The structure of copolymer was confirmed by FTIR spectroscopy. The thermal stability, linear coefficient of thermal expansion, modulus, X‐ray pattern, and other properties, such as surface enrichment behavior and solubility, were investigated. PSBPI exhibited relatively low crystallinity regardless of the APMFS content in the copolymer. On the other hand, thermogravimetric, thermomechanical, dynamic mechanical, and surface properties were affected by the content of APMFS segment in the copolymer backbone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2867–2874, 2002
Preparation, physico‐chemical characterization, and optical analysis of polyvinyl alcohol‐based films suitable for protected cultivation
Authors: De Prisco Nicola , Immirzi Barbara , Malinconico Mario , Mormile Pasquale , Petti Lucia , Gatta Giuseppe 
Published: October 2002

AbstractThe use of biodegradable polymer films for mulching is a topic of great interest both from the environmental point of view and for the intrinsic properties that the above films, when appropriately designed, might have. In the present article we report on a synthetic approach that, starting from existing biodegradable polymers, leads to a new material characterized by a time‐controlled biodegradation. The idea that subsides is to bridge polyvinyl alcohol (PVOH) chains through polycaprolactone (PCL) crosslinks. In such a way, PVOH looses its water sensitivity and can stand on the ground for the time needed for the mulching to occur, while the PCL crosslinks, being sensitive to (slow) fungal attack, will undergo cleavage, followed by the complete bio‐assimilation of the residual PVOH chains. The number of crosslinks introduced can control time of biodegradation. The polymers are characterized in their intrinsic chemical‐physical properties, while a preliminary evaluation of their efficiency as mulches is obtained through the analysis of their thermal behavior when deposited on an irrigated soil. The results are also compared with a model approach able to predict the thermal behavior of a film in specific environmental conditions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 622–632, 2002
Predicting the reactivity of phenolic compounds with formaldehyde. II. Continuation of an ab initio study
Authors: Mitsunaga Tohru , Conner Anthony H. , Hill Charles G. 
Published: October 2002

AbstractPhenol–formaldehyde resins are important adhesives used by the forest products industry. The phenolic compounds in these resins are derived primarily from petrochemical sources. Alternate sources of phenolic compounds include tannins, lignins, biomass pyrolysis products, and coal gasification products. Because of variations in their chemical structures, the reactivities of these phenolic compounds with formaldehyde vary in quite subtle ways. Previously, it was demonstrated that the reactivity of a number of phenols with formaldehyde in nonaqueous conditions could be correlated with charges calculated for reactive sites on the aromatic ring (Conner, A. H. J Appl Polym Sci 2000, 78, 355–363). We studied the reactivity of a larger number of phenolic compounds with formaldehyde in an aqueous solution using sodium hydroxide as the catalyst. Reaction rates were determined from measurements of the concentrations of the phenolic compounds and formaldehyde as functions of time. The reaction rate constants varied over a wide range (approximately 10−2 to 104 L mol−1 h−1). An estimate of the reactivity per reactive site on the phenolic ring was determined by dividing the rate by the number of reactive sites. Atomic charges for each phenolic compound were calculated by ab initio methods at the RHF/6‐31+ G level of theory using the CHelpG method. The charge per reactive site was estimated by summing the charges at all the reactive sites on the phenolic ring and dividing by the number of reactive sites. A strong correlation was observed between the reactivity per reactive site and the average charge per reactive site. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 135–140, 2002
Solubility of carbon dioxide in polyethylene/titanium dioxide composite under high pressure and temperature
Authors: Areerat Surat , Hayata Yusuke , Katsumoto Ryuichi , Kegasawa Tadahiro , Egami Hideo , Ohshima Masahiro 
Published: October 2002

AbstractSolubility of carbon dioxide (CO2) in a low‐density polyethylene (LDPE)/titanium dioxide (TiO2) composite was measured using a magnetic suspension balance (MSB) at a temperature from 423 to 473 K and pressures up to 15 MPa. The effect of the TiO2 concentration on the solubility is investigated by varying TiO2 content in the range of 0–20 wt %. Extending the Sanchez–Lacombe equation of state and its mixing rule for binary mixture, a scheme of calculating CO2 solubility in composite from MSB data is developed. The solubility of CO2 in the composites increases in proportion to pressure and exponentially decreases with temperature. The apparent solubility, which is defined by the weight of dissolved CO2 per unit weight of the composite, decreases as the TiO2 content increases. However, the true solubility, which can be defined by the weight of dissolved CO2 per unit weight of polymer, is constant, although the TiO2 content is changed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 282–288, 2002
Permeation of H2, N2, CH4, C2H6, and C3H8 through asymmetric polyetherimide hollow‐fiber membranes
Authors: Wang Dongliang , Teo W. K. , Li K. 
Published: October 2002

AbstractPermeation properties of pure H2, N2, CH4, C2H6, and C3H8 through asymmetric polyetherimide (PEI) hollow‐fiber membranes were studied as a function of pressure and temperature. The PEI asymmetric hollow‐fiber membrane was spun from a N‐methyl‐2‐pyrrolidone/ethanol solvent system via a dry‐wet phase‐inversion method, with water as the external coagulant and 50 wt % ethanol in water as the internal coagulant. The prepared asymmetric membrane exhibited sufficiently high selectivity (H2/N2 selectivity >50 at 25°C). H2 permeation through the PEI hollow fiber was dominated by the solution‐diffusion mechanism in the nonporous part. For CH4 and N2, the transport mechanism for gas permeation was a combination of Knudsen flow and viscous flow in the porous part and solution diffusion in the nonporous part. In our analysis, operating pressure had little effect on the permeation of H2, CH4, and N2. For C2H6 and C3H8, however, capillary condensation may have occurred at higher pressures, resulting in an increase in gas permeability. As far as the effect of operating temperature was concerned, H2 permeability increased greatly with increasing temperature. Meanwhile, a slight permeability increment with increasing temperature was noted for N2 and CH4, whereas the permeability of C2H6 and C3H8 decreased with increasing temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 698–702, 2002
Graft copolymerization of styrene and acrylonitrile onto EPDM
Authors: Qu Xiongwei , Shang Shurui , Liu Guodong , Zhang Liucheng 
Published: October 2002

AbstractAcrylonitrile–EPDM–styrene (AES) graft copolymers were synthesized by solution graft polymerization of styrene (St) and acrylonitrile (AN) onto EPDM in an n‐hexane/benzene solvent with benzoyl peroxide (BPO) as an initiator. The structure changes were studied by an FTIR spectrophotometer. The grafting parameters were calculated gravimetrically. The influence of the polymerization conditions, such as the reaction time, concentration of the initiator, EPDM content, and weight ratio of St/AN, on the structure of the products was investigated. It was found that a proper initiator concentration and EPDM content will give a high grafting ratio of the AES resin. The thermal property of the copolymer was studied using programmed thermogravimetric analysis (TGA). The results showed that the copolymer has a better heat‐resistant property than that of ABS, especially for the initial decomposition temperature (Tin) and the maximum weight loss rate temperature (Tmax). Also, the mechanism of the graft reaction was discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 428–432, 2002
Complete discontinuity of the distal fistula tract from the developing gut: Direct histologic evidence for the mechanism of tracheoesophageal fistula formation
Authors: Spilde Troy L. , Bhatia Amina M. , Marosky Julie K. , Hembree Mark J. , Kobayashi Hiroyuki , Daume Erica L. , Prasadan Krishna , Manna Pradip , Preuett Barry L. , Gittes George K. 
Published: October 2002

AbstractThe embryogenesis of tracheoesophageal anomalies remains controversial. The purpose of this study was to better define the embryogenesis of developing esophageal atresia with tracheoesophageal fistula (EA/TEF), with specific attention to the controversial issue of whether a discontinuity exists in the foregut during its development of EA/TEF. Pregnant outbred rats were injected with adriamycin (2 mg/kg i.p.) on days 6–9 of gestation (E6–E9). At E12.5 and 13.5, microdissection of the entire foregut was performed. Foreguts were examined by phase microscopy, and serial, precisely transverse sections were created for hematoxylin and eosin (H&E) staining. Gross microdissection of the developing foregut at E12.5 (n = 9) revealed a blind‐ending, bulbous fistula tract arising from the middle branch of the tracheal trifurcation (as seen by direct and phase microscopy). No connection with the gut could be appreciated at E12.5, but by E13.5 (n = 10) there was an obvious connection between the fistula and the stomach. Serial H&E transverse sections also demonstrated a blind‐ending fistula tract arising from the trachea at E12.5. This fistula tract was clearly discontinuous from the developing stomach, which appeared much further caudal to the end of the fistula tract. These results strongly support a model of experimental TEF wherein the fistula tract arises from a trifurcation of the trachea, and (only during a specific gestational window between days 12.5 and 13.5) there is discontinuity between the fistula tract and the stomach. By day 13.5, the fistula joins with the stomach anlage. These observations in the developing EA/TEF should help to resolve the controversy about the mechanism of EA/TEF formation. Anat Rec 267:220–224, 2002. © 2002 Wiley‐Liss, Inc.