bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of verbalization on face recognition in young and older adults
Authors: Memon Amina , Bartlett James
Published: September 2002

To explore the forensic implications of ‘verbal overshadowing’ in young and older eyewitnesses, we examined the effects of providing a verbal face description on subsequent performance in a lineup task. Young (18–30 years) and older (60–80 years) adults viewed a videotaped crime and performed some unrelated cognitive tasks. Participants in the experimental condition were then asked to supply a description of the target person in the event or to perform a control task. Upon completing the description/control task participants attempted to identify the target person from a target present photo‐lineup presented in a sequential or simultaneous mode. Older participants made more false choices and sequential testing reduced correct choices. There was a weak trend consistent with verbal overshadowing that was unrelated to age as well as measures of verbal and face‐matching expertise. Although overshadowing reduced performance only slightly, it appeared to affect the self‐reported use of a feature‐matching strategy linked to accurate decisions by young adults and inaccurate decisions by senior adults. Copyright © 2002 John Wiley & Sons, Ltd.
Visuospatial memory and phonological loop in learning from multimedia
Authors: Gyselinck Valérie , Cornoldi Cesare , Dubois Véronique , De Beni Rossana , Ehrlich Marie‐France
Published: September 2002

The dual‐task paradigm was used to show how visuospatial working memory and the phonological loop are involved in processing scientific texts and illustrations presented via computer. In experiment 1, two presentation formats were compared: text‐only and text‐with‐illustrations. With a concurrent tapping task, the beneficial effect of illustrations disappeared, while a concurrent articulatory task impaired performance similarly in both presentation formats. An analysis of individual differences revealed that this pattern of results was present in high, but not low spatial span subjects. These results support the selective involvement of visuospatial working memory in processing illustrated texts. In Experiment 2, the text‐only presentation format was compared to an illustrations‐only format. The concurrent articulatory task selectively impaired text‐only processing, compared with processing illustrations‐only. In addition, this pattern of results was found for high, but not low digit span subjects. These results suggest that individual differences define the extent to which the two subsystems of working memory are involved in learning from multimedia. These two subsystems would be mainly involved in the maintenance of a visual trace of illustrations and of a verbatim representation of linguistic information respectively, these representations being the basis for higher‐level comprehension processes. Copyright © 2002 John Wiley & Sons, Ltd.
Irrelevant speech and indoor lighting: effects on cognitive performance and self‐reported affect
Authors: Knez Igor , Hygge Staffan
Published: September 2002

This study examined the disruption of cognitive performance by ecologically valid, office and school like settings with warm‐ or cool‐white lighting and silence or meaningful, irrelevant, conversational speech, and whether any such susceptibility was attributable to the changes in affective states. The study aims to address the lack of data on combined impact of noise and light on humans in previous research and to complement findings of irrelevant sound effect in list memory studies. No interactions between noise and light were shown, but there were main effects of noise and light on long‐term memory recall and of noise on self‐reported affect. Cool‐white compared to warm‐white lighting impaired the long‐term memory recall of a novel text. Learning from this text was, in addition, disrupted by meaningful, irrelevant, conversational speech: an impact that was not mediated by affect. The obtained noise effect suggests that the meaning in irrelevant sound was processed, to some extent, semantically by the subjects, which disrupted their performance in a cognitive task that also involved processing of meaning. Copyright © 2002 John Wiley & Sons, Ltd.
Energetic consequences of being a Homo erectus female
Authors: Aiello Leslie C. , Key Cathy
Published: September 2002

Body size is one of the most important characteristics of any animal because it affects a range of behavioral, ecological, and physiological traits including energy requirements, choice of food, reproductive strategies, predation risk, range size, and locomotor style. This article focuses on the implications of being large bodied for Homo erectus females, estimated to have been over 50% heavier than average australopithecine females. The energy requirements of these hominins are modeled using data on activity patterns, body mass, and life history from living primates. Particular attention is given to the inferred energetic costs of reproduction for Homo erectus females based on chimpanzee and human reproductive scheduling. Daily energy requirements during gestation and lactation would have been significantly higher for Homo erectus females, as would total energetic cost per offspring if the australopithecines and Homo erectus had similar reproductive schedules (gestation and lactation lengths and interbirth intervals). Shortening the interbirth interval could considerably reduce the costs per offspring to Homo erectus and have the added advantage of increasing reproductive output. The mother would, however, incur additional daily costs of caring for the dependent offspring. If Homo erectus females adopted this reproductive strategy, it would necessarily imply a revolution in the way in which females obtained and utilized energy to support their increased energetic requirements. This transformation is likely to have occurred on several levels involving cooperative economic division of labor, locomotor energetics, menopause, organ size, and other physiological mechanisms for reducing the energetic load on females. Am. J. Hum. Biol. 14:551–565, 2002. © 2002 Wiley‐Liss, Inc.
Comparative and evolutionary dimensions of the energetics of human pregnancy and lactation
Authors: Dufour D.L. , Sauther M.L.
Published: September 2002

The purpose of this article is to compare the energetics of reproduction for human and other primates in order to evaluate the extent to which human reproductive energetics are distinct from other primates and other large‐bodied placental mammals. The article also evaluates the energetics of human and primate gestation and lactation using data from a variety of different populations living under different environmental circumstances. Energetics refers to energy intake and expenditure, and changes in body fat stores. Human and nonhuman primates have longer periods of gestation and lactation and slower prenatal and postnatal growth than other mammals of similar size. This reduces daily maternal energy costs. The development of sizable fat stores is not unique to humans, but fat stores are typically greater in human females and may play a greater role in reproduction. The strategies used to meet the energy costs of pregnancy vary among populations of humans and nonhuman primates and among humans interindividual variability is high. In pregnancy, some increase energy intake but others apparently do not. Increases in metabolic efficiency are evident in some human populations, whereas decreases in physical activity occur, but are not seen in all human or primate populations. Lactation is more energetically costly on a daily basis among humans and nonhuman primates, but has not been as well studied. It appears that both nonhuman and human primates tend to increase energy intake to meet in part the cost of lactation. They also use other strategies such as relying on body tissue stores, reductions in physical activity, and/or increases in metabolic efficiency to meet the remainder of the cost. It is also clear that human females in different populations and different women in the same population use a different combination of strategies to meet the cost of lactation. Am. J. Hum. Biol. 14:584–602, 2002. © 2002 Wiley‐Liss, Inc.
Climatic influences on basal metabolic rates among circumpolar populations
Authors: Leonard William R. , Sorensen Mark V. , Galloway Victoria A. , Spencer Gary J. , Mosher M.J. , Osipova Ludmilla , Spitsyn Victor A.
Published: September 2002

This article examines evidence for elevations in basal metabolic rate (BMR) among indigenous Northern (circumpolar) populations and considers potential mechanisms and the adaptive basis for such elevations. Data on BMR among indigenous (n = 109 males; 122 females) and nonindigenous (n = 15 males; 22 females) circumpolar groups of North America and Siberia are compiled and compared to predicted BMRs based on three different references: body surface area (Consolazio et al., 1963), body mass (Schofield, 1985), and fat‐free mass (Poehlman and Toth, 1995). Regardless of which reference is used, indigenous circumpolar groups show systematic and statistically significant elevations in BMR ranging from +7% to +19% above predicted values for indigenous men and from +3 to +17% for indigenous women. Nonindigenous males also show elevations in BMR, although not to the same extent as in indigenous men (deviations = +3 to +14%), whereas nonindigenous females show no clear evidence of elevated BMRs (deviations = −7 to +5%). This pattern of variation between indigenous and nonindigenous groups suggests that both functional and genetic factors play a role in metabolic adaptation to northern climes. Recent studies on the ecology and genetics of thyroid function offer insights into the mechanisms through which indigenous circumpolar populations may regulate metabolic rates. Studies of seasonal variation in thyroid hormone levels suggest that indigenous circumpolar populations may have a greater capacity to elevate BMR during severe cold than nonindigenous groups. Recent twin studies indicate a significant genetic component of thyroid responses to environmental stressors. Further research exploring the genetics of seasonal variation in thyroid function and BMR among circumpolar groups would advance understanding of the role that selection may have played in shaping metabolic variation. Am. J. Hum. Biol. 14:609–620, 2002. © 2002 Wiley‐Liss, Inc.
Somatic versus reproductive energy allocation in Papua New Guinea: Life history theory and public health policy
Authors: Tracer David P.
Published: September 2002

A fundamental evolutionary problem faced by organisms is how to allocate energy to somatic and reproductive functions in ways that optimize fitness. Given that energy is limited in all environments, energy allocation necessarily involves physiological tradeoffs between such factors as growth and reproduction, reproduction and condition, and current reproduction and future survival. Ultimately, the “decisions” that are made about energy allocation among growth, survival, and reproduction determine life history patterns and trajectories of organisms. For humans, knowing how energy allocation to reproduction will likely impact other aspects of the somatic well‐being of individuals may also have practical implications for public health policy. This article reviews the evidence for energy tradeoffs between somatic and reproductive functioning in a range of human societies. It also seeks to corroborate the results of earlier work in Papua New Guinea on lactation‐related maternal energy depletion using an independent measure of maternal energy reserves, tetrapolar bioelectrical impedance analysis. The current analysis shows that maternal energy reserves decline over the course of lactation and that a cumulative parity‐specific decline in maternal energy reserves also exists. A longitudinal follow‐up of five women over 11 years shows the decline to amount to about 3 mm of subcutaneous fat per round of pregnancy and lactation. The results corroborate predictions from life history theory and have applied public health implications. In particular, It is suggested that policies such as lactation advocacy that encourage enhanced energy allocation to reproduction in order to promote child health may have the unintended result of compromising maternal well‐being, particularly in nations of the developing world. Consequently, it is recommended that nutritional support of mothers be implemented in concert with lactation promotion. Am. J. Hum. Biol. 14:621–626, 2002. © 2002 Wiley‐Liss, Inc.
Sexual division of labor: Energetic and evolutionary scenarios
Authors: Panter‐Brick Catherine
Published: September 2002

This article examines comparative energetic data on hunter–gatherers in the context of evolutionary scenarios of the sexual division of labor, with respect to both specific task allocation and overall levels of daily physical activity. The division of labor between men and women, well marked in contemporary foraging societies, was once posited as the “true watershed” for the evolution of the genus Homo. Some research on brain‐wiring even links sex differences in cognitive and spatial abilities to sex‐specific foraging activities. Most recent evolutionary arguments posit that men focus on hunting and women on gathering activities to realize potentially conflicting mating and parenting goals. A range of cooperative strategies (male/female and female/female) for child provisioning is also under investigation. Attention to energetic and reproductive trade‐offs has usefully challenged the proposition that women are excluded from big‐game hunting due to constraints of foraging ecology and reproduction. Simplistic assumptions about gender roles are thus increasingly questioned in anthropology, as well as in archaeology. Current models in behavioral ecology explore ways in which foraging practices vary with ecological circumstances, aiming to derive testable hypotheses from fine‐grained data on the behavior of contemporary hunter–gatherers. Data on overall physical activity levels (PAL) can also serve to evaluate relative male/female workloads in modern groups, reconstruct hominid energy requirements and activity profiles, and examine changes with subsistence intensification. Male/female PAL ratios show that a task‐specific division of labor does not readily extrapolate to 24‐hour energy expenditure and that male/female differences in workloads were not necessarily reduced with the transition to agriculture. With respect to gender roles and PAL, a shift away from facile stereotypes of human behavior is evident. The challenge is to incorporate a range of behavioral responses to ecological circumstances in reconstructions of our evolutionary past. Am. J. Hum. Biol. 14:627–640, 2002. © 2002 Wiley‐Liss, Inc.
Factor analysis of ethnic variation in the multiple metabolic (insulin resistance) syndrome in three Canadian populations
Authors: Kue Young T. , Chateau Daniel , Zhang Min
Published: September 2002

This study describes and compares the pattern of risk factor clustering in multiple metabolic (insulin resistance) syndrome (MMS) in three Canadian ethnic groups (Indians, Inuit, non‐Aboriginal Canadians). Three cross‐sectional, population‐based sample surveys in three contiguous regions of Canada were conducted during the late 1980s and early 1990s (Ontario, Manitoba, Northwest Territories). The combined dataset consists of 873 Cree‐Ojibwa Indians from northern Ontario and Manitoba, 387 Inuit from the Northwest Territories, and 2,670 non‐Aboriginal Canadians (predominantly of European origin) in the province of Manitoba. The samples are representative of the noninstitutionalized, adult population of their respective catchment areas. Factor analysis transformed 10 anthropometric and metabolic variables into three uncorrelated factors. Three factors, which together account for 64.3% of the variance, can be identified: an “obesity factor” (factor loadings for weight, height, waist and hip girth, and HDL‐cholesterol); a “blood pressure factor” (factor loadings for mean systolic and diastolic BP and total cholesterol); and a “lipid/glucose factor” (factor loadings for triglycerides, total cholesterol, HDL, and fasting plasma glucose). Fasting insulin is available for only a subset of the data and separate analysis shows that it groups with glucose. Factor scores generated by the factor analysis differ according to ethnic group, diabetes status, and sex on multivariate analysis of variance. Indians have the highest scores for all three factors. Inuit have the lowest obesity scores and are not significantly different from non‐Aboriginal people with regard to the other two factors. MMS is prevalent in diverse ethnic groups but varies in the pattern of phenotypic expression, with some components more prominent in some groups. Am. J. Hum. Biol. 14:649–658, 2002. © 2002 Wiley‐Liss, Inc.
Comparative energetics of primate fetal growth
Authors: Ulijaszek Stanley J.
Published: September 2002

Among the primates, Homo sapiens has evolved a life history which includes long gestation, relatively slow growth to reproductive maturity, and large body size. While the slow growth rate may be linked to the energetic demands of having a large brain, there are other important morphological and physiological linkages that may be adaptive, including the development of significant fat stores with which to buffer against episodic and periodic energetic stress. In this comparative analysis of the energetic burden of pregnancy among primates (including humans), the daily energy investment in the development of neonatal tissue is modeled. During pregnancy, larger primates, notably the Hominidae, invest a smaller proportion of their maternal daily nonmaintenance energy budget in fetal tissue with increasing energy budget, allowing diverse adaptations, including foraging strategies which include folivory and mixed patterns of food getting, and meat consumption. Humans have a similar proportion of maternal daily nonmaintenance energy budget invested in fetal tissue with increasing energy budget to other apes and have a diet which is of much higher quality than predicted for body size and metabolic needs. The combination of high diet quality and low proportion of maternal daily nonmaintenance energy budget invested in fetal tissue allows greater brain size relative to body weight at birth compared with all other primates, apart from chimpanzees, and higher birthweight and body fatness at birth for a given body size than other primate species. Am. J. Hum. Biol. 14:603–608, 2002. © 2002 Wiley‐Liss, Inc.
Growth charts for nose length, nasal protrusion, and philtrum length from birth to 97 years
Authors: Zankl Andreas , Eberle Lukas , Molinari Luciano , Schinzel Albert
Published: September 2002

Craniofacial measurements are an integral part in the evaluation of a dysmorphic patient. Since the clinical impression can be misleading, dysmorphic features should be validated by quantitative criteria wherever possible. Anthropometric measurements have been used in the characterization of many dysmorphic syndromes. However, data on normal craniofacial measurements is sparse and incomplete. In this study, we present normal values for nose size and philtrum length based on measurements on 2,500 healthy individuals of central European origin, ranging in age from zero to 97 years. © 2002 Wiley‐Liss, Inc.
Primary hypothyroidism and osteopenia associated with Neuhauser syndrome
Authors: Sarkozy Anna , Mingarelli Rita , Brancati Francesco , Dallapiccola Bruno
Published: September 2002

We report on a patient affected by Neuhauser megalocornea‐mental retardation (MMR) syndrome, presenting with most of the major manifestations of this disorder, in association with primary hypothyroidism and osteopenia. These symptoms, previously reported in single patients, could be discrete features of MMR syndrome. © 2002 Wiley‐Liss, Inc.
Greenberg dysplasia (hydrops–ectopic calcification–moth‐eaten skeletal dysplasia): Prenatal ultrasound diagnosis and review of literature
Authors: Trajkovski Zoran , Vrcakovski Miodrag , Saveski Jordan , Gucev Zoran S.
Published: September 2002

A second pregnancy of young, nonconsanguineous parents of Macedonian ethnic origin was examined by ultrasound. Polyhydramnios and hydrops fetalis were found as well as severe short limb, short stature, and cystic hygroma of the neck. An artificial abortion was performed at the age of 23 weeks. The radiological features included moth‐eaten severely shortened long bones and ectopic calcifications of long bones, vertebral column, ribs, pelvis, larynx, trachea. In addition, the fetus had large head with depressed nasal bridge, severe platyspondyly, and short barrel‐shaped trunk. Light microscopy demonstrated lack of chondrocyte columns and disorganization of the cartilaginous architecture. This is the seventh reported case of this rare form of lethal skeletal dysplasia. © 2002 Wiley‐Liss, Inc.
Apparently new osteodysplastic and primordial short stature with severe microdontia, opalescent teeth, and rootless molars in two siblings
Authors: Kantaputra Piranit N.
Published: September 2002

A Thai man and his sister affected with a newly recognized syndrome of proportionate primordial short stature are reported. The patients had severe intrauterine and postnatal growth retardation, prominent nose and nasal bridge, small pinnae, large sella turcica, areas of hypo‐ and hyperpigmentation of skin, dry and thin scalp hair, and long and straight clavicles. Ivory epiphyses and cone‐shaped epiphyses of the hands were found when they were young, but most of them disappeared as they grew up. Scaphoid and trapezium had angular appearance. The second toes were unusually long. Distal symphalangism of toes and barchymesophalangy of fingers were noted. The findings that appear to distinguish this syndrome from the previously reported syndromes are long second toes, opalescent and rootless teeth, severe microdontia, severely hypoplastic alveolar process, and unerupted tooth. The mode of inheritance is suspected to be autosomal recessive. © 2002 Wiley‐Liss, Inc.
Tetrasomy Y by structural rearrangement: Clinical report
Authors: DesGroseilliers Martin , Lemyre Emmanuelle , Dallaire Louis , Lemieux Nicole
Published: September 2002

Poly‐Y karyotypes, except for 47,XYY, are rare events in humans. For instance, Y chromosome tetrasomy has been reported 10 times, 2 of which were by structural rearrangement. We present a 2‐year‐and‐4‐month‐old boy who was referred for cytogenetic assessment because of global psychomotor delay. The GTG‐ and CBG‐banded karyotypes on PHA‐stimulated lymphocytes showed two cell populations, one of them contained two identical isodicentric Y chromosomes, which was seen in 93% of metaphases analyzed, and a 45,X cell line (7%). This was confirmed by FISH with probes DYZ3 (recognizing the centromeric region of the Y chromosome), 91H4.5 (recognizing Yp11.2), and DYZ1 (recognizing Y heterochromatin in Yq12). The breakpoint has occurred near the telomeric end of the heterochromatic region. Therefore, the karyotype is mos 47,X,idic(Y)(q12)x2[123]/45,X[9]. This is the second time that such a karyotype has been reported. This chromosomal anomaly was formed most likely by a U‐type exchange. Clinical features included speech delay, short stature, brachycephaly, large ears, bilateral epicanthal folds, hypertelorism, delayed teeth eruption, bilateral radio‐ulnar synostosis, bilateral fifth finger clinodactyly, normal external genitalia, and impulsive behavior. The father had normal phenotype and karyotype. A review of the tetrasomy Y patients is presented. All patients with Y chromosome tetrasomy exhibit some degree of mental retardation, various skeletal abnormalities, and facial dysmorphism. Nevertheless, the correlation between karyotype and phenotype is not yet well defined since few cases have been reported. This clinical report will be helpful in defining the phenotypic range associated with tetrasomy Y. © 2002 Wiley‐Liss, Inc.
Velo‐cardio‐facial syndrome: Clinical report of a 70‐year‐old woman
Authors: Verhoeven W.M.A. , Tuinier S. , Engelen J.J.M. , Hollanders‐Crombach H.T.M. , Curfs L.M.G.
Published: September 2002

A clinical report is presented of a 70‐year‐old female in whom, after more than 40 years residential psychiatric care, the diagnosis of velo‐cardio‐facial syndrome (VCFS) was ultimately established; the patient has a 46, XX.ish del (22)(q11.2q11.2)(D22S75‐) karyotype. It is advocated that a rather specific psychopathological profile is present in patients with VCFS, for which the term psychopathological phenotype is introduced, that should include data from genetics, neuropathology, development, psychology, and psychiatry. © 2002 Wiley‐Liss, Inc.
Setleis syndrome: Three new cases and a review of the literature
Authors: McGaughran Julie , Aftimos Salim
Published: September 2002

Setleis syndrome is characterized by cutis aplasia or atrophic skin at the temples, which is said to resemble forceps marks. There may also be a coarse facial appearance, anomalies of the eyelashes and eyebrows, and periorbital puffiness. The mouth has a typical appearance with large lips, inverted “V” contour, and downturned overly defined corners. Patients usually have normal intelligence. Here are presented three cases with features of Setleis syndrome. One is an apparently isolated case; the others are father and son. All three have developmental delay. This second family is a further example of autosomal dominant inheritance in Setleis syndrome. These patients also suggest that developmental problems may be a more common manifestation than previously described. Two of the patients are the first described of Pacific Island descent. © 2002 Wiley‐Liss, Inc.
Cyst‐like cerebral lesions in tuberous sclerosis
Authors: Rott Hans‐Dieter , Lemcke Beate , Zenker Martin , Huk Walter , Horst Jürgen , Mayer Karin
Published: September 2002

Known brain manifestations of tuberous sclerosis (TSC) are cortical sclerotic tubera, giant cell astrocytomas, subependymal calcified nodules in the lateral walls of the lateral ventricles, and white matter heterotopias. In addition, small cyst‐like lesions in the white matter have been described. We report on three TSC patients with hitherto undescribed large cyst‐like cerebral lesions in subcortical and white matter locations. We emphasize that cystoid brain degeneration is a rare but typical cerebral manifestation of TSC and suggest that, in patients with such lesions, TSC should be taken into consideration. © 2002 Wiley‐Liss, Inc.
Contexts and behavioral correlates of trill vocalizations in wild white‐faced capuchin monkeys (Cebus capucinus)
Authors: Gros‐Louis Julie
Published: September 2002

Primate vocalizations that appear to occur independently of specific contexts typically are considered to be contact calls. However, results from several recent studies indicate that these calls function to facilitate social interactions. White‐faced capuchin monkeys (Cebus capucinus) emit a high‐frequency vocalization, termed a “trill,” in social interactions and during travel. In this study, immatures emitted most trills, but adult females also trilled; by contrast, adult males rarely trilled. Infants emitted the majority of trills, and they trilled at significantly higher rates than adult females. Infants trilled most when approaching other individuals. Furthermore, infants emitted proportionately more trills than other age classes when approaching other individuals. I therefore focused on the detailed context and immediate behavioral correlates of trilling by infants. Infants that trilled when approaching others tended to interact affiliatively with them subsequently (i.e., climbing on, touching, receiving grooming, and performing food inspection) more than infants that did not trill when approaching. Therefore, infant trilling may have had an immediate effect on the recipient's behavior. Am. J. Primatol. 57:189–202, 2002. © 2002 Wiley‐Liss, Inc.
Chromosomal homologies between Cebus and Ateles (Primates) based on ZOO‐FISH and G‐banding comparisons
Authors: García F. , Ruiz‐Herrera A. , Egozcue J. , Ponsà M. , Garcia M.
Published: September 2002

ZOO‐FISH (Fluorescent “in vitro” hybridization) was used to establish the chromosomal homology between humans (HSA) and Cebus nigrivitatus (CNI) and Ateles belzebuth hybridus (ABH). These two species belong to different New World monkey families (Cebidae and Atelidae, respectively) which differ greatly in chromosome number and in chromosome morphology. The molecular results were followed by a detailed banding analysis. The ancestral karyotype of Cebus was then determined by a comparison of in situ hybridization results, as well as chromosomal morphology and banding in other Platyrrhini species. The karyotypes of the four species belonging to the genus Cebus differ from each other by three inversions and one fusion as well as in the location and amounts of heterochromatin. Results obtained by ZOO‐FISH in ABH are in general agreement with previous gene‐mapping and in situ hybridization data in Ateles, which show that spider monkeys have highly derived genomes. The chromosomal rearrangements detected between HSA and ABH on a band‐to‐band basis were 27 fusions/fissions, 12 centromeric shifts, and six pericentric inversions. The ancestral karyotype of Cebus was then compared with that of Ateles. The rearrangements detected were 20 fusions/fissions, nine centromeric shifts, and five inversions. Atelidae species are linked by a fragmentation of chromosome 4 into three segments forming an association of 4/15, while Ateles species are linked by 13 derived associations. The results also helped clarify the content of the ancestral platyrrhine karyotype and the mode of chromosomal evolution in these primates. In particular, associations 2/16 and 5/7 should be included in the ancestral karyotype of New World monkeys. Am. J. Primatol. 57:177–188, 2002. © 2002 Wiley‐Liss, Inc.
Improvement in the adhesion of polyimide/epoxy joints using various curing agents
Authors: Hun Kim Seong , Woo Lee Dong , Chung Kyung‐Ho , Ki Park Jae , Jaung Jae‐Yun , Hoon Jeong Sung
Published: September 2002

An improvement in the adhesion strength of polyimide/epoxy joints was obtained by (1) introducing a functional group on the polyimide surface, (2) improving the mechanical properties of the epoxy adhesive, (3) increasing the curing temperature, and (4) using polyamic acid as an adhesion‐promoting layer. The functional group on polyimide was introduced via treatment with aqueous KOH. An adhesion‐promoting layer was formed by spin coating polyamic acid onto a modified polyimide surface. The maximum adhesion strength of the polyimide/epoxy joint was obtained using polyamic acid as both the adhesion‐promoting layer and as the curing agent. The surface energy of the modified polyimide was examined using contact angle measurements and Fourier transform infrared spectroscopy, and the peel strength was determined by the T‐peel method. The peeled surfaces were analyzed using scanning electron microscopy and X‐ray photoelectron spectroscopy.© 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 812–820, 2002
Spinnability and physical properties of in situ composite fibers based on thermotropic liquid crystalline polymer
Authors: He Xiaojun , Ellison Michael S. , Paradkar Rajesh P.
Published: September 2002

In situ composite fibers based on poly(ethylene 2,6‐naphthalate) (PEN) and a thermotropic liquid crystalline polymer (Vectra A950) were prepared using a single‐screw extruder. The fibers were taken up at selected speeds. The spinnability, thermal behavior, mechanical properties, and morphologies of the PEN/Vectra A950 blend were investigated. The results showed that the PEN/Vectra A950 blends were partly miscible, and the miscibility increased with the increased concentration of Vectra in the blend. The DSC measurements indicated that Vectra enhanced the crystallization process of PEN by performing as a nucleating agent. The Instron tensile property study, coupled with scanning electron microscopy, revealed that the mechanical properties of the PEN matrix were significantly improved when Vectra existed as long and continuous fibrils. The laser Raman results showed that the Vectra orientation began to develop at take‐up speeds above 500 m/min. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 795–811, 2002
Properties and toughening of heat‐resistant thermosets based on unsaturated ester resins
Authors: Canelas Dorian A. , Abbey Kirk J. , Fentress Emily
Published: September 2002

We describe our investigations of the curing chemistry and properties of heat‐resistant thermosets comprised of unsaturated ester resins. We suggest a mechanism for the rearrangement of the cured matrix and volatile evolution during the curing process. We employed dielectric spectroscopy (DES) as a tool for monitoring the extent of cure, determining glass‐transition temperatures, and evaluating electrical properties of the resins. We compare and contrast results obtained by DES to results obtained by dynamic mechanical analysis (DMA). Fracture testing showed that improvements were made in the toughness of these materials by blending the uncured resin with impact modifiers such as hydrocarbon or silicone reactive rubber adducts or poly(arylene ether sulfone)‐based thermoplastic oligomers. We determined the effects of the thermoplastic toughening additive's molecular weight, concentration, and endgroup functionality on the phase separation, thermal stability, and fracture toughness of the blend. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 821–843, 2002
Biodegradable polymers based on renewable resources. VI. Synthesis and biodegradability of poly(ester carbonate)s containing 1,4:3,6‐dianhydro‐D‐glucitol and sebacic acid units
Authors: Okada Masahiko , Yokoe Makito , Aoi Keigo
Published: September 2002

Poly(ester carbonate)s with different compositions were synthesized by bulk polycondensation of 1,4:3,6‐dianhydro‐D‐glucitol with diphenyl sebacate and diphenyl carbonate in the presence of zinc acetate as a catalyst. Most of the poly(ester carbonate)s as well as the corresponding polycarbonate were amorphous, except the poly(ester carbonate) with a small carbonate content and the corresponding polyester, which are semicrystalline. All these poly(ester carbonate)s are soluble in chloroform, pyridine, dimethylformamide, dimethyl sulfoxide, and N,N‐dimethylacetamide. Soil burial degradation tests, biochemical oxygen demand (BOD) measurements in an activated sludge, and enzymatic degradation tests indicated that these poly(ester carbonate)s are potentially biodegradable. The biodegradability was found to be maximum for the poly(ester carbonate)s with carbonate contents of 10–20 mol % and to decrease markedly for the poly(ester carbonate)s with the carbonate content above 50 mol %. The biodegradability of the poly(ester carbonate)s is discussed in terms of the crystallinity, glass transition temperature, and surface hydrophobicity of the polymer films. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 872–880, 2002
Influence of particle surface properties on film formation from precipitated calcium carbonate/latex blends
Authors: Tang Jiansheng , Daniels Eric S. , Dimonie Victoria L. , Klein Andrew , El‐Aasser Mohamed S.
Published: September 2002

The surface properties of films prepared from a blend of precipitated calcium carbonate pigment (PCC) and poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) [P(BMA/BA); Tg = 0°C] latex were investigated in terms of the surface characteristics of the PCC and P(BMA/BA) latex particles. It was found that the presence of carboxyl groups on the P(BMA/BA) latex particles significantly improved the uniformity of the distribution of the PCC particles within the P(BMA/BA) copolymer matrix and the gloss of the resulting films. This phenomenon could be explained by an acid‐base reaction between the PCC particles and the carboxylated P(BMA/BA) latex particles. Studies on the influence of the composition of PCC/P(BMA/BA) latex blends on the gloss and transparency of the films were also performed, which led to the determination of the critical pigment volume concentration (CPVC) of this system, which was found to be 42 vol %. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 891–900, 2002
Fundamental adsorption properties of chitosan gel particles prepared by suspension evaporation method
Authors: Igarashi Keiji , Nakano Yoshio
Published: September 2002

Chitosan gel particles were prepared by the suspension evaporation method, and their fundamental adsorption properties have been investigated. The chitosan gel particles were spherical in shape, 150 μm in diameter, and had large macropores, about 2 μm in diameter, formed by the polymer networks. The adsorption properties were evaluated from an interaction viewpoint using anionic surfactants having various numbers of carbon atoms, ethylbenzenesulfonate (EBS), octylbenzenesulfonate (OBS), and dodecylbenzenesulfonate (DBS). The pKa values of the amino groups within the gel particles were remarkably small compared with those of chitosan polymer. EBS, with its short hydrophobic chain, was adsorbed mainly by an electrostatic interaction in the pH range 3.0 to 6.0, where the amino groups were dissociated. On the contrary, the adsorption of OBS and DBS, with their relatively long hydrophobic chains, took place via an electrostatic interaction in the pH range 3.0 to 5.0, and then by a hydrophobic interaction in the presence of an electrostatic interaction in the pH range 5.0 to 8.0. We conclude that an electrostatic interaction is essential, even for the adsorption of surfactants having strong hydrophobic interactions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 901–906, 2002
Plasma‐induced surface modification and adhesion enhancement of polypropylene surface
Authors: Bhat N. V. , Upadhyay D. J.
Published: September 2002

Unoriented (UPP) and biaxially oriented (BOPP) polypropylene films were treated under radio frequency plasma of air, nitrogen, oxygen, and ammonia. Surface modification of polypropylene films was investigated by using surface energy measurement and attenuated total reflection (ATR)‐FTIR spectroscopy. Surface energy of air and nitrogen plasma‐treated polypropylene film increased for shorter treatment time and then decreased and attained an equilibrium value. Such changes in surface energy were not observed for oxygen and ammonia plasma‐treated polypropylene film, which increased to an equilibrium value. ATR‐FTIR studies revealed characteristic differences in the absorption spectra for short‐duration and long‐duration treatments. From the relative intensity change in the C—H stretching vibration, the mechanism of surface chemical reaction could be inferred. Studies regarding the durability of surface modification due to plasma treatment were evaluated by investigating surface energy of samples aged for 2 months. Treated films subjected to peel strength measurement showed improvement in bondability for UPP and BOPP film by hydrophilic surface modification accompanied by surface crosslinking. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 925–936, 2002
Thermal degradation kinetics of para‐substituted poly (styrene peroxide)s in solution
Authors: De Priyadarsi , Chattopadhyay Sujay , Madras Giridhar , Sathyanarayana D. N.
Published: September 2002

The thermal degradation of three polymeric peroxides of styrene monomers with substituents in the para position was studied at various temperatures (65, 75, 85, and 95°C). A continuous distribution model was used to evaluate the rate coefficients for the random‐chain and chain‐end scission degradation from the evolution of molecular weight distributions with time. The activation energy determined from the temperature dependence of the rate coefficients was in the range 18–22 kcal mol−1. This result suggests that the thermal degradation of polyperoxide is controlled by the dissociation of the O—O bonds in the polymer backbone. The thermal stability for poly(p‐methylstyrene peroxide) lies in between that of poly(p‐tert‐butylstyrene peroxide) (highest) and poly(p‐bromostyrene peroxide) (lowest). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 957–961, 2002
Intermolecular and intramolecular hydrogen bonding of poly(dimethylsiloxane)urethane‐graft–poly(methyl methacrylate) copolymers based on 2,4‐TDI and m‐XDI
Authors: Ma Chen‐Chi M. , Wang Feng‐Yih , Du Yi‐Chang , Wu Chen‐Li , Chiang Chin‐Lung , Hung Albert Y. C.
Published: September 2002

In this study, poly(dimethylsiloxane)urethane–graft–poly(methyl methacrylate) (PDMS urethane–g–PMMA) copolymers with low crosslinking density were synthesized. Glass transition temperatures of the copolymers were investigated by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Results confirm that PDMS urethane–g–PMMA is miscible in the 2,4‐TDI (2,4‐ toluene diisocyanate) system, whereas it is partially miscible in the m‐XDI (m‐xylene diisocyanate) system. Free, intra‐ (urethane–urethane), and inter‐ (urethane–ester) association hydrogen bonding exist in the urethane group of copolymers. The inter‐association hydrogen bonding can improve the compatibility of the copolymer components. The relationship between the frequency shift and enthalpy confirm the distribution of hydrogen bonding in the macromonomer and copolymer. Ninety percent of the hydrogen bonding is by interassociation in the 2,4‐TDI system. The intra‐association hydrogen bonding in the m‐XDI system is higher than that in the 2,4‐TDI system. Consequently, aggregation may occur easily in the siloxane‐grafted chain in the m‐XDI system. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 962–972, 2002
Self‐affine fractal scaling in fracture surfaces generated in ethylene and propylene polymers and copolymers
Authors: Lapique Fabrice , Meakin Paul , Feder Jens , Jøssang Torstein
Published: September 2002

The fracturing of four different polyolefin materials was studied with the objective of developing a better understanding of the relationships between the morphology of the semicrystalline polymers, the morphology of their fracture surfaces and their mechanical properties. This article is focussed on the quantitative description of the fractures surfaces. The surface structure can be described in terms of self‐affine fractal models, and the Hurst exponent(s) and roughness measurements can be used to describe quantitatively the fracture surface topography. Fracture surfaces generated in homopolymers can be described by a single Hurst exponent, which differs for PE and PP. For copolymers with PE and PP matrices, the Hurst exponent measured on small‐length scales was the same as that obtained for the matrix material, but a crossover to a second regime, with a higher Hurst exponent, was found at longer length scales. The crossover was related to the average distance between rubber particles for the PP/PE rubber phase specimen (PP‐copo). The introduction of a second component seems to modify the crack propagation at long‐length scales, but the propagation at shorter length scales remains unchanged. Environmental stress cracking experiments indicate that each regime can be related to brittle or ductile fracturing processes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 973–983, 2002
Nonisothermal bulk crystallization of high‐density polyethylene via a modified depolarized light microscopy technique: Further analysis
Authors: Supaphol Pitt , Spruiell Joseph E.
Published: September 2002

The quiescent nonisothermal bulk crystallization kinetics of high‐density polyethylene was investigated with a modified depolarized light microscopy technique, which allowed for studies at average cooling rates of approximately 5–2500 °C min−1. All of the samples crystallized at a pseudoisothermal temperature (i.e., the plateau or crystallization temperature), despite the nonisothermal nature of the cooling conditions. The rate of the crystallization process increased monotonically with increasing the cooling rate and decreasing the crystallization temperature. Moreover, the apparent crystallinity content was a certain decreasing function with the cooling rate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1009–1022, 2002
Synthesis and characterization of functionalized syndiotactic polystyrene copolymers
Authors: Li Chi‐Lan , Chan Shu‐Hua , Ting Ching , Jiang George J.
Published: September 2002

Functionalized syndiotactic polystyrene copolymers were synthesized and characterized. The syndiotactic polystyrene copolymers, poly(styrene‐co‐4‐methylstyrene) (sPSMS), were prepared by styrene with 4‐methylstyrene with a metallocene/methylaluminoxane catalyst. In addition, grafted copolymers, chemically grafted with isoprene onto an sPSMS backbone [poly(styrene‐co‐4‐methylstyrene)‐g‐polyisoprene (sPSMS‐g‐PIP)] were synthesized by anionic grafting polymerization with a metallation reagent. In this study, we also examined the effect of the degree of functionalization (epoxidation) on the polymer structure of the sPSMS‐g‐PIP copolymers. Experimental results indicate that the crystallinity of the sPSMS‐g‐PIP copolymer was lower than that of the ungrafted sPSMS copolymer. Moreover, the epoxy‐containing sPSMS‐g‐PIP copolymer effectively increased the thermal stability more than did the sPSMS‐g‐PIP copolymer alone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1038–1045, 2002
Morphology of iPP spherulites crystallized in a temperature gradient
Authors: Pawlak Andrzej , Chapel Jean‐Paul , Piorkowska Ewa
Published: September 2002

The influence of temperature gradient on the lamellar structure of isotactic polypropylene spherulites was studied. Polypropylene films were crystallized in a constant temperature gradient of 35 K/mm with the free surface and studied by means of atomic force microscopy and scaning electron microscopy. Samples crystallized isothermally were also prepared and examined for comparison. The results show that the temperature gradient influenced only the alignment of lamellae within spherulites. The lamellae deviated from a radial direction in a stepwise manner. The lamellae became less and less inclined and finally assumed a direction parallel to the temperature gradient. The change of the lamellae alignment in spherulites was the result of the competition of lamellae to fill the space during growth in the temperature gradient. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1318–1328, 2002
Modeling of polymer crystallization in a temperature gradient
Authors: Piorkowska Ewa
Published: September 2002

The crystallization of polymer films in a temperature gradient was simulated. The curvature of lamella growth directions observed experimentally was taken into account. The computer simulation permitted the visualization of the evolution of the spherulitic pattern and also the calculation of the conversion of the melt into spherulites. The mathematical model was also elaborated and allowed the prediction of the kinetics of conversion during the crystallization of polymers in the temperature gradient. A good agreement between the computer simulation results, the mathematical model predictions, and the experimental data for isotactic polypropylene crystallized in a temperature gradient was obtained. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1351–1362, 2002