bluuebunny/crossref_metadata_2025_split huggingface dataset:
Demography, life history, and social structure in Propithecus diadema edwardsi from 1986–2000 in Ranomafana National Park, Madagascar
Authors: Pochron Sharon T. , Tucker W. Troy , Wright Patricia C. 
Published: July 2004

AbstractProsimian lemurs differ fundamentally from anthropoid primates in many traits related to social structure. By exploring the demography of Milne‐Edwards' sifakas (Propithecus diadema edwardsi), and comparing it to other well‐studied primates, we explore the effect of demographic and life‐history factors on social structure. Specifically, we compare lemur survivorship and fertility patterns to two published composite models: one created for New World and another created for Old World monkeys. Using longitudinal data collected on individual Propithecus diadema edwardsi from four study groups from 1986–2000 in Ranomafana National Park, Madagascar, we quantify 1) group composition, 2) birth seasonality, 3) interbirth interval, 4) life‐table values, and 5) population growth estimates. The mortality, survivorship, and life‐expectancy schedules indicate high infant and juvenile mortality. Fertility remains high until death. The intrinsic rate of increase and net reproductive rate indicate a shrinking population. We suggest that high mortality rather than low fertility causes the observed population decline. While sifaka survivorship closely resembles New World patterns, fertility resembles Old World patterns, i.e., like New World monkeys, few sifakas survive to reproductive age, and those that do, reproduce at a slow rate resembling the Old World pattern. This necessarily impacts social structure. An adult sifaka at the end of her lifespan will have one only daughter who survives to reproductive age, compared to 3.4 for New World or 2.7 for Old World monkeys. Demography limits the formation of large kin‐based groups for sifakas, and survivorship and fertility patterns do not easily permit sifakas to form large same‐sex family groups. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
Molar size and shape variations among Asian colobines
Authors: Willis Mary S. , Swindler Daris R. 
Published: July 2004

AbstractDespite decades of research, little is known about morphometric differences within the dentition of Asian colobines. Although some differences, such as the M3 hypoconulid, are often cited as distinct among genera, no comprehensive assessment has been made. The objectives of this study were to document size and shape differences in third molars in eight Asian colobine genera, including Kasi, Nasalis, Presbytis, Pygathrix, Rhinopithecus, Semnopithecus, Simias, and Trachypithecus, and to quantify length differences for all molars in order to understand the potential impact of an occlusal surface area that includes the hypoconulid. To achieve these objectives, the most extensive survey yet published of Asian colobine dentition was conducted. Differences within and among genera for continuous and categorical variables were analyzed using descriptive statistics, chi‐square, t‐tests, and post hoc comparisons. Results indicate that species of Presbytis differ from all other Asian colobines in both the size and shape of the maxillary and mandibular third molars. Specifically, M3 of Presbytis is relatively shorter in length and less likely to exhibit a hypoconulid optimally positioned for occlusion with M3. Moreover, Presbytis expresses concomitant changes in the maxillary third molar such as absence of a distal shelf and/or a distal cusp with separated crests. We conclude that shape and size changes impact the molar size sequence patterns of Presbytis, setting this genus apart from all other Asian colobine taxa. These differences may reflect variation in overall body size, dietary adaptation, and phylogeny. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
Role of carnivores in the accumulation of the Sterkfontein Member 4 hominid assemblage: A taphonomic reassessment of the complete hominid fossil sample (1936–1999)
Authors: Pickering Travis Rayne , Clarke Ron J. , Moggi‐Cecchi Jacopo 
Published: July 2004

AbstractNew taphonomic data on the Sterkfontein Member 4 (South Africa) fossil hominid assemblage are presented. The previous estimate of hominid individuals represented in the deposit (45) is increased to 87. New minimum numbers of hominid skeletal elements are provided, and incidences of bone surface damage inflicted by prehistoric biological agents are summarized. The hominid sample from Member 4 is composed predominately of gnathic remains and has a paucity of postcrania. This dearth of postcrania limits, to some extent, inferences about the formation of the Sterkfontein assemblage. However, carnivore tooth marks on some fossil specimens and an overall broad similarity in patterns of skeletal part representation between Sterkfontein and primate bone assemblages created by extant carnivores suggest that carnivores did have some involvement in the accumulation of the fossil hominid assemblage. Thus, this study provides support for the “carnivore‐collecting hypothesis” of Brain (Brain [1981] The Hunters or the Hunted? Chicago: University of Chicago Press), which implicates large carnivores as prominent collecting agents of hominid body parts in Sterkfontein Member 4. Evidence of bone surface damage is, however, too scant to make confident inferences about specific carnivore taxon/taxa involved in hominid bone collection at the site. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
DYS19 and DYS199 loci in a Chilean population of mixed ancestry
Authors: Cifuentes L. , Morales R. , Sepúlveda D. , Jorquera H. , Acuña M. 
Published: July 2004

AbstractThe current Chilean population originated from admixture between aboriginal populations (Amerindians) and Spanish conquerors of European origin. Consequently, the unions that gave rise to the Chilean population were chiefly between Spanish males and aboriginal females, and not the converse. To test the hypothesis that the Y chromosome of the Chilean population is mainly of Spanish origin, while the other chromosomes are from mixed (European and aboriginal) origin, we studied the DYS19 and DYS199 loci in two samples. One sample was obtained from a high socioeconomic stratum, while a second sample was from a low stratum. We studied male blood donors (N = 187) from Santiago, the capital of the country. Subjects were typed for the autosomal ABO and Rh (locus D) blood groups, and for the Y‐linked DYS19 and the DYS199 loci, reported as Y‐chromosome haplotypes. The aboriginal admixture was estimated for each genetic marker. The percentage of aboriginal admixture was 38.17% for the ABO system and 31.28% for the Rh system in the low socioeconomic stratum and 19.22% and 22.5%, respectively, in the high stratum. Y‐chromosome haplotype frequencies constructed from the DYS19 and DYS199 loci demonstrated that the main haplotypes were DYS19*14/DYS199 C, as is often the case with many European populations, and DYS19*13/DYS199 C. The aboriginal admixture from Y‐haplotype frequencies was estimated to be 15.83% in the low socioeconomic stratum and 6.91% in the high stratum. These values are lower than the values found using autosomal genetic markers, and are consistent with the historical background of the population studied. This study highlights the population genetic consequences of the asymmetric pattern of genome admixture between two ancestral populations (European and Amerindian). Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
Interferon‐β stabilizes barrier characteristics of brain endothelial cells in vitro
Authors: Kraus Jörg , Ling Anne K. , Hamm Stefan , Voigt Kay , Oschmann Patrick , Engelhardt Britta 
Published: July 2004

AbstractMultiple sclerosis (MS) is accompanied by a breakdown of the blood–brain barrier (BBB) leading to edema formation and aggravation of the disease. Interferon‐β (IFN‐β) has been approved for the treatment of MS and besides its immunomodulatory effects has been demonstrated to lead to a stabilization of BBB integrity in vivo. To investigate whether human recombinant IFN‐β exerts direct effects on the BBB, we used an in vitro BBB model in which brain endothelial cells in coculture with astrocytes form a tight permeability barrier for 3H‐inulin and 14C‐sucrose. Removal of the astrocytes from the coculture or alternatively addition of histamine resulted in an increased paracellular permeability for small tracers across the brain endothelial cell monolayer. Strikingly, in the presence of IFN‐β, permeability increase under both conditions was inhibited. Permeability changes were accompanied by minor changes in the staining for tight junction–associated proteins in brain endothelial cell monolayers. Taken together, our data demonstrate a direct stabilizing effect of IFN‐β on BBB cerebral endothelial cells in vitro that might significantly contribute to the beneficial effects of IFN‐β treatment in MS in vivo. Ann Neurol 2004;56:192–205
Fuel utilization in patients with very long‐chain acyl‐coa dehydrogenase deficiency
Authors: ØRngreen Mette C. , Nørgaard Mette G. , Sacchetti Massimo , Van Engelen Baziel G. M. , Vissing John 
Published: July 2004

AbstractFuel utilization in two adult patients with the myopathic form of very long‐chain acyl‐CoA dehydrogenase (VLCAD) deficiency and five healthy subjects was investigated with stable isotopes during exercise at 50% of VO2max. The findings indicate that residual VLCAD activity in the patients is sufficient to maintain normal oxidation of fat at rest, but that fat oxidation rate cannot increase above basal levels during exercise. This can cause an energy deficit and intramuscular accumulation of fat intermediates that may induce the exercise‐induced symptoms.
Folic acid supplementation enhances repair of the adult central nervous system
Authors: Iskandar Bermans J. , Nelson Aaron , Resnick Daniel , Pate Skene J. H. , Gao Peng , Johnson Chenara , Cook Thomas D. , Hariharan Nithya 
Published: July 2004

AbstractFolic acid supplementation has proved to be extremely effective in reducing the occurrence of neural tube defects (NTDs) and other congenital abnormalities in humans, suggesting that folic acid can modulate key mechanisms for growth and differentiation in the central nervous system (CNS). To prevent NTDs, however, supplemental folate must be provided early in gestation. This suggests that the ability of folic acid to activate growth and differentiation mechanisms may be confined to the early embryonic period. Here, we show that folic acid can enhance growth and repair mechanisms even in the adult CNS. Using lesion models of CNS injury, we found that intraperitoneal treatment of adult rats with folic acid significantly improves the regrowth of sensory spinal axons into a grafted segment of peripheral nerve in vivo. Regrowth of retinal ganglion cell (RGC) axons into a similar graft also was enhanced, although to a smaller extent than spinal axons. Furthermore, folic acid supplementation enhances neurological recovery from a spinal cord contusion injury, showing its potential clinical impact. The results show that the effects of folic acid supplementation on CNS growth processes are not restricted to the embryonic period, but can also be effective for enhancing growth, repair, and recovery in the injured adult CNS. Ann Neurol 2004;56:221–227
SOD2 gene transfer protects against optic neuropathy induced by deficiency of complex I
Authors: Qi Xiaoping , Lewin Alfred S. , Sun Liang , Hauswirth William W. , Guy John 
Published: July 2004

AbstractMutations in genes encoding the NADH ubiquinone oxidoreductase, complex I of the respiratory chain, cause a diverse group of diseases. They include Leber hereditary optic neuropathy, Leigh syndrome, and mitochondrial encephalomyopathy with lactic acidosis and stroke‐like episodes. There is no effective treatment for these or any other mitochondrial disorder. Using a unique animal model of severe complex I deficiency induced by ribozymes targeted against a critical complex I subunit gene (NDUFA1), we attempted rescue of the optic nerve degeneration associated with Leber hereditary optic neuropathy. We used adenoassociated virus to deliver the human gene for SOD2 to the visual system of disease‐induced mice. Relative to mock infection, SOD2 reduced apoptosis of retinal ganglion cells and degeneration of optic nerve fibers, the hallmarks of this disease. Rescue of this animal model supports a critical role for oxidative injury in disorders with complex I deficiency and shows that a respiratory deficit may be effectively treated in mammals, thus offering hope to patients. Ann Neurol 2004;56:182–191
Novel haplotypes in 17q21 are associated with progressive supranuclear palsy
Authors: Pastor Pau , Ezquerra Mario , Perez J. Christian , Chakraverty Sumi , Norton Joanne , Racette Brad A. , McKeel Dan , Perlmutter Joel S. , Tolosa Eduardo , Goate Alison M. 
Published: July 2004

AbstractProgressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are sporadic neurodegenerative diseases presenting as atypical parkinsonian disorders, characterized by the presence of tau‐positive neurofibrillary tangles. Recently, an extended haplotype (H1E) of 787.6kb that comprises several genes including MAPT showed increased association with PSP. The objective of this study was to determine the size of the H1E haplotype associated with PSP and CBD in different populations and to identify specific subhaplotypes in the background of H1E haplotype. Nineteen single nucleotide polymorphisms (SNPs) in the 17q21 region were genotyped in two case–control samples. The SNPs that were associated with higher risk for the disease in the homozygous state delimit a region of more that 1Mb. Haplotype analyses in the Spanish sample showed that the most frequent haplotype found among the patients (H1E′), which extends 1.04Mb and contains several genes such as MAPT, CRHR1, IMP5, Saitohin, WTN3, and NSF. A specific subhaplotype (H1E′A) was present in 16% of PSP patients but was not observed in the controls. Furthermore, the H2E′A haplotype, was rarely present in the disease group suggesting that it plays a protective role. The identification of these specific subhaplotypes that modify risk for PSP/CBD supports the hypothesis that a pathogenic allele exists in a subgroup of PSP patients. Ann Neurol 2004;56:249–258
PGE2 receptors rescue motor neurons in a model of amyotrophic lateral sclerosis
Authors: Bilak Masako , Wu Liejun , Wang Qian , Haughey Norman , Conant Katherine , St. Hillaire Coryse , Andreasson Katrin 
Published: July 2004

AbstractRecent studies suggest that the inducible isoform of cyclooxygenase, COX‐2, promotes motor neuron loss in rodent models of ALS. We investigated the effects of PGE2, a principal downstream prostaglandin product of COX‐2 activity, on motor neuron survival in an organotypic culture model of ALS. We find that PGE2 paradoxically protects motor neurons at physiological concentrations in this model. PGE2 exerts its downstream effects by signaling through a class of four distinct G‐protein–coupled E‐prostanoid receptors (EP1–EP4) that have divergent effects on cAMP. EP2 and EP3 are dominantly expressed in ventral spinal cord in neurons and astrocytes, and activation of these receptor subtypes individually or in combination also rescued motor neurons. The EP2 receptor is positively coupled to cAMP, and its neuroprotection was mimicked by application of forskolin and blocked by inhibition of PKA, suggesting that its protective effect is mediated by downstream effects of cAMP. Conversely, the EP3 receptor is negatively coupled to cAMP, and its neuroprotective effect was blocked by pertussis toxin, suggesting that its protective effect is dependent on Gi‐coupled heterotrimeric signaling. Taken together, these data demonstrate an unexpected neuroprotective effect mediated by PGE2, in which activation of its EP2 and EP3 receptors protected motor neurons from chronic glutamate toxicity. Ann Neurol 2004;56:240–248
Adaptation of the attention network in human immunodeficiency virus brain injury
Authors: Chang Linda , Tomasi Dardo , Yakupov Renat , Lozar Carl , Arnold Sheeba , Caparelli Elisabeth , Ernst Thomas 
Published: July 2004

AbstractHuman immunodeficiency virus (HIV)–positive patients commonly have attention and concentration problems. However, it remains unclear how HIV infection affects the attention network. Therefore, blood oxygenation level dependent functional magnetic resonance imaging (BOLD‐fMRI) was performed in 36 subjects (18 HIV and 18 seronegative [SN] controls) during a set of visual attention tasks with increasing levels of attentional load. Compared with SN controls, HIV subjects showed similar task performance (accuracies and reaction times) but decreased activation in the normal visual attention network (dorsal parietal, bilateral prefrontal, and cerebellar regions) and increased activation in adjacent or contralateral brain regions. Cognitive performance (assessed with NPZ‐8), CD4, and viral load all correlated with activated BOLD signals in brain regions that activated more in HIV subjects. Furthermore, HIV subjects activated more than SN controls in brain regions that showed load‐dependent increase in activation (right prefrontal and right parietal regions) but less in regions that showed a saturation effect with increasing load. These findings suggest that HIV‐associated brain injury leads to reduced efficiency in the normal attention network, thus requiring reorganization and increased usage of neural reserves to maintain performance during attention‐requiring tasks. Exceeding the brain reserve capacity may lead to attention deficits and cognitive impairment in HIV patients. Ann Neurol 2004;56:259–272
Tensile behavior and morphology studies of glass‐fiber‐reinforced polymeric in situ hybrid composites
Authors: Liu Hua , Liao Kin 
Published: July 2004

AbstractThe morphology and tensile behavior of an in situ hybrid composite system, based on E‐glass‐fibers, liquid‐crystalline polymers, and Noryl (a modified polyphenylene ether/polystyrene blend) with a hierarchical microstructure containing reinforcements with an order‐of‐magnitude difference in size, were studied. The primary reinforcement was short E‐glass fibers, and the secondary reinforcement was formed by LCP inclusions with submicrometer dimensions generated in situ during fabrication. With an increase in the LCP content, both the geometry and dimensions of the LCP phase in the composites changed, from spherical droplets to ellipsoidal droplets and then to fibrils or lamellar structures. The orientation of the short E‐glass fibers was influenced by this change, and the breakage of the glass fibers during processing was less intensive. The tensile strength of the composites increased moderately with the addition of LCPs and the reduction of the glass‐fiber content. The elastic modulus of the composites did not follow rule‐of‐mixture predictions. This more complicated hybrid effect was attributed to several competing mechanisms. Tensile fractography analysis indicated that the tensile fracture of the composites was dominated by fiber/matrix‐interface failure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 211–221, 2004
Correlations between the processing variables and morphology of crosslinked polyethylene
Authors: Gulmine J. V. , Akcelrud L. 
Published: July 2004

AbstractCrosslinked polyethylene (XLPE) is progressively replacing other types of polyethylene in electric cable insulation because of its combination of better mechanical and thermal performance and good dielectric properties. Besides its influence on the mechanical and thermal properties, the morphology plays a very important role in the electrical behavior of XLPE. The morphology has been studied in terms of the crystallinity and crosslinking density. These two apparently independent parameters govern the morphology of XLPE and have been investigated in connection with the systematic variation of the processing parameters (crosslinker concentration, cure time, and temperature). The materials have been characterized in terms of the extent of crosslinking (the gel content), the crosslinking density (the average molecular weight between crosslinks), and the crystallinity. A morphological model is proposed for these materials in terms of the mechanisms and rates of the processes involved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 222–230, 2004
Mathematical modeling of the phase behaviors of solid‐polymer‐electrolyte/salt systems in lithium secondary batteries: The nonrandomness effect
Authors: Pai Sung Jin , Bae Young Chan , Kong Sung Ho , Ryu Si Ok 
Published: July 2004

AbstractWe establish a new melting‐point‐depression theory, based on the modified‐double‐lattice model, that takes into account the local composition concept to describe the phase behaviors of solid‐polymer‐electrolyte/salt systems (modified‐double‐lattice/nonrandom model). In comparison with experimental data, quantitative descriptions of the proposed model show better agreement for the given systems than those of the modified‐double‐lattice model. The systems studied in this work are combinations of poly(ethylene oxide) and zinc halides and of poly(ethylene oxide) and LiCF3SO3. The results show that the nonrandomness effect of the salt distribution plays a major role in determining the eutectic points of the given systems. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 231–237, 2004
Amphiphilic poly(styrene‐b‐ethylene oxide)‐block‐copolymer‐intercalated layered silicate and its nanocomposites with acrylonitrile–butadiene– styrene resin
Authors: Guo Tianying , Hao Guangjie , Song Moudao , Zhang Banghua 
Published: July 2004

AbstractAmphiphilic poly(styrene‐b‐ethylene oxide) block copolymers were synthesized by sequential anionic copolymerization. Layered silicates intercalated by the block copolymers were prepared via melt intercalation. The effects of the intercalated clay on an acrylonitrile–butadiene–styrene resin were characterized with X‐ray diffraction, transmission electron microscopy, stress–strain measurements in elongation, and thermogravimetric analysis. X‐ray and microscopy results demonstrated that the main structure of the dispersed block‐copolymer‐intercalated clay in the acrylonitrile–butadiene–styrene resin matrix was mono‐ and bundle‐ layered. Further studies demonstrated that the resin showed considerable improvement in its tensile strength, modulus, and thermal stability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 238–242, 2004
A novel method for synthesis of water‐soluble polypyrrole with horseradish peroxidase enzyme
Authors: Nabid Mohammad Reza , Entezami Ali Akbar 
Published: July 2004

AbstractA novel water‐soluble, conducting polypyrrole was synthesized by horseradish peroxidase (HRP), in the presence of sulfonated polystyrene, as a polyanionic template. The HRP is an effective catalyst for the oxidative polymerization of pyrrole in the presence of hydrogen peroxide at room temperature. The reaction is sensitive to solution pH and it is performed in pH 2 aqueous solutions. Polymerization of pyrrole by this biological route produced a conducting water‐soluble polypyrrole for the first time. The reaction is benign and in one pot, and the product requires minimal purification. The reversible redox activity of the polypyrrole displays a hystersis loop with pH changes. FT‐IR, UV‐vis absorption spectroscopy, and cyclic voltammetry are used in the characterization of the synthesized polypyrrole. These studies confirm the electroactive and conducting form of polypyrrole, similar to that which has been traditionally synthesized, chemically and electrochemically. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 254–258, 2004