bluuebunny/crossref_metadata_2025_split huggingface dataset:
Waiting for Trivers and Willard: Do the rich really favor sons?
Authors: Koziel Slawomir , Ulijaszek Stanley J. 
Published: August 2002

AbstractParental investment theory has been put forward as a major evolutionary argument explaining male or female biased birth sex ratio, the Trivers‐Willard (T‐W) hypothesis, predicting that parents living in good circumstances will bias their investment to sons, whereas parents in poor circumstances will bias their investment toward daughters. Tests of the T‐W hypothesis on human beings have shown limited evidence for parents appearing to differentiate their investment to sons or daughters according to the reproductive potential of each sex. The present study tests the T‐W hypothesis among a large contemporary Polish sample using first birth interval and extent of breastfeeding as measures of parental investment, and economic status and level of parental education as measures of parental condition. The extents to which parental investment and markers of parental condition vary by sex of the child were examined using log‐linear analysis. Weak support for the T‐W effect is found among families where fathers were best educated, where a greater proportion of first‐born boys are breastfed longer than girls, while the opposite trend is observed among families with fathers with lowest levels of education. Although the present study does not fully support the T‐W hypothesis, it gives evidence of greater investment in female offspring at the lower extremes of income, and greater investment in males at higher levels of income. Am J Phys Anthropol 115:71–79, 2001. © 2001 Wiley‐Liss, Inc.
Ontogeny of canine dimorphism in extant hominoids
Authors: Schwartz Gary T. , Dean Christopher 
Published: August 2002

AbstractMany behavioral and ecological factors influence the degree of expression of canine dimorphism for different reasons. Regardless of its socioecological importance, we know virtually nothing about the processes responsible for the development of canine dimorphism. Our aim here is to describe the developmental process(es) regulating canine dimorphism in extant hominoids, using histological markers of tooth growth. Teeth preserve a permanent record of their ontogeny in the form of short‐ and long‐period incremental markings in both enamel and dentine. We selected 52 histological sections of sexed hominoid canine teeth from a total sample of 115, from which we calculated the time and rate of cuspal enamel formation and the rate at which ameloblasts differentiate along the future enamel‐dentine junction (EDJ) to the end of crown formation. Thus, we were able to reconstruct longitudinal growth curves for height attainment in male and female hominoid canines. Male hominoids consistently take longer to form canine crowns than do females (although not significantly so for our sample of Homo). Male orangutans and gorillas occasionally take up to twice as long as females to complete enamel formation. The mean ranges of female canine crown formation times are similar in Pan, Gorilla, and Pongo. Interspecific differences between female Pan canine crown heights and those of Gorilla and Pongo, which are taller, result from differences in rates of growth. Differences in canine crown heights between male Pan and the taller, more dimorphic male Gorilla and Pongo canines result both from differences in total time taken to form enamel and from faster rates of growth in Gorilla and Pongo. Although modern human canines do not emerge as significantly dimorphic in this study, it is well‐known that sexual dimorphism in canine crown height exists. Larger samples of sexed modern human canines are therefore needed to identify clearly what underlies this. Am J Phys Anthropol 115:269–283, 2001. © 2001 Wiley‐Liss, Inc.
Growth and ontogeny of sexual size dimorphism in the mandrill (Mandrillus sphinx)
Authors: Setchell Joanna M. , Lee Phyllis C. , Wickings E. Jean , Dixson Alan F. 
Published: August 2002

AbstractWe present body mass (N = 419) and crown‐rump length (CRL, N = 210) measurements from 38 male and 49 female mandrills born into a semifree‐ranging colony in order to describe growth from birth to adulthood, and to investigate maternal influences upon growth. Adult male mandrills are 3.4 times the body mass, and 1.3 times the CRL, of adult females. Body mass dimorphism arises from a combination of sex differences in length of the growth period (females attain adult body mass at 7 years, males at 10 years) and growth rate. Both sexes undergo a subadult growth spurt in body mass, and this is much more dramatic in males (peak velocity 551 g/months ± 89 SEM at 84–96 months). CRL dimorphism arises from bimaturism (females attain adult CRL at 6 years, males after 10 years), and neither sex shows a particular subadult growth spurt in CRL. Sexual size dimorphism thus represents important time and metabolic costs to males, who mature physically approximately 3–4 years after females. Considerable interindividual variation occurs in the size‐for‐age of both sexes, which is related to maternal variables. Older mothers have heavier offspring than do younger mothers, and higher‐ranking mothers have heavier offspring than do lower ranking mothers. Mass advantages conferred upon offspring during lactation by older and higher‐ranking mothers tend to persist postweaning in both sexes. Thus maternal factors affect reproductive success in both sexes, influencing the age at which offspring mature and begin their reproductive career. Am J Phys Anthropol 115:349–360, 2001. © 2001 Wiley‐Liss, Inc.
Lake pigments facilitate analysis of fecal cortisol and behavior in group‐housed macaques
Authors: Stavisky Ronda C. , Whitten Patricia L. , Hammett David H. , Kaplan Jay R. 
Published: August 2002

AbstractFecal steroid analyses are becoming more popular among both field and laboratory scientists. The benefits associated with sampling procedures that do not require restraint, anesthesia, and blood collection include less risk to both subject and investigator, as well as the potential to obtain endocrine profiles that do not reflect the influence of stress. However, the utility of the fecal steroid method has been limited in field conditions because of problems associated with sample identification. Here, we present evidence that Lake pigments are a valuable tool for the identification of individual fecal samples from group‐housed female cynomolgus macaques. Further, we present data that suggest that excreted cortisol can be assayed from such samples, leading to the finding that time of day of sample collection influences cortisol concentrations, with morning samples producing higher values (t = 2.769, P = 0.024). Finally, the collection of physiological data from group‐housed animals permits the evaluation of the relationship between endocrine status and behavior. This study demonstrated that morning fecal cortisol was significantly correlated with competitive and proximity behaviors, although not with rank in two stable social groups. In conclusion, the utility and validity of fecal steroid analyses continue to expand with further investigations. Am J Phys Anthropol 116:51–58, 2001. © 2001 Wiley‐Liss, Inc.
Association between high‐density lipoprotein and cognitive impairment in the oldest old
Authors: Van Exel Eric , de Craen Anton J. M. , Gussekloo Jacobijn , Houx Peter , Bootsma‐van der Wiel Annetje , Macfarlane Peter W. , Blauw Gerard J. , Westendorp Rudi G. J. 
Published: August 2002

AbstractLow high‐density lipoprotein cholesterol is associated with an increased risk for cardiovascular disease and stroke. At the same time, cardiovascular disease and stroke are important risk factors for dementia. We assessed the association between total and fractionated cholesterol and cognitive impairment and explored whether observed associations were dependent on or independent of atherosclerotic disease. In a population‐based study, total cholesterol, triglycerides, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol were measured in 561 subjects 85 years old and grouped in three equal strata representing decreasing serum concentrations. History of cardiovascular disease and stroke was determined. All subjects completed the Mini‐Mental State Examination (MMSE), and the presence of dementia was determined. Median MMSE scores were significantly lower in subjects with low high‐density lipoprotein cholesterol (25 points vs 27 points, p < 0.001). No differences in MMSE scores were found for other lipids and lipoproteins. MMSE scores in subjects with and without cardiovascular disease were 26 and 27 points (p = 0.007), respectively, and in subjects with and without stroke were 21 and 26 points (p < 0.001), respectively. The associations between low MMSE scores and low high‐density lipoprotein cholesterol remained significant after subjects with cardiovascular disease or stroke were excluded. In a comparison of subjects with low high‐density lipoprotein cholesterol with subjects with high high‐density lipoprotein cholesterol, the odds ratio for dementia was 2.3 (95% confidence interval, 1.2–4.3), and in subjects without cardiovascular disease or stroke, it was 3.7 (95% confidence interval, 1.3–10.1). All odds ratios were unaffected by education, low‐density lipoprotein cholesterol, triglycerides, and survival. Low high‐density lipoprotein cholesterol is associated with cognitive impairment and dementia. At least part of the association between high‐density lipoprotein cholesterol and cognitive function is independent of atherosclerotic disease.
Neuroimmunophilins: Novel neuroprotective and neuroregenerative targets
Authors: Guo Xin , Dillman James F. , Dawson Valina L. , Dawson Ted M. 
Published: August 2002

AbstractCyclosporin A (CsA) and FK506 (tacrolimus) are immunosuppresants that are widely used in organ transplantation. CsA is an 11‐member cyclic peptide, whereas FK506 is a macrolide antibiotic. Recently, these powerful and useful compounds have become of great interest to neuroscientists for their unique neuroprotective and neuroregenerative effects. These drugs and nonimmunosuppressive analogs protect neurons from the effects of glutamate excitotoxicity, focal ischemia, and 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced dopaminergic cell death. They also stimulate functional recovery of neurons in a variety of neurologic injury paradigms. These drugs exert their effects via immunophilins, the protein receptors for these agents. The immunophilin ligands show particular promise as a novel class of neuroprotective and neuroregenerative agents that have the potential to treat a variety of neurologic disorders.
Ocular flutter associated with a localized lesion in the paramedian pontine reticular formation
Authors: Schon Fred , Hodgson Timothy L. , Mort Dominic , Kennard Christopher 
Published: August 2002

AbstractOcular flutter is a rare horizontal eye movement disorder characterised by rapid saccadic oscillations. It has been hypothesised that it is caused by loss of “pause” neuronal inhibition of “burst” neuron function in the paramedian pontine reticular formation (PPRF); however there have been no imaging studies confirming such anatomical localisation. We report the case of a woman with an acute attack of multiple sclerosis associated both with ocular flutter and a circumscribed pontine lesion, mainly involving the PPRF on magnetic resonance imaging. As she recovered from the attack, both the midline pontine lesion and the ocular flutter dramatically improved. This case is the first clear evidence that at least some cases of ocular flutter are due to lesions involving the PPRF.
Arsenic concentrations and speciation in a temperate mangrove ecosystem, NSW, Australia
Authors: Kirby J. , Maher W. , Chariton A. , Krikowa F. 
Published: August 2002

AbstractTotal arsenic concentrations and species were measured in the sediments, vegetation and tissues of marine animals from a temperate mangrove ecosystem. Mean arsenic concentrations ranged from 0.3 to 55 µg g−1 dry mass. Epiphytic algae/fungi associated with mangrove fine roots had relatively higher arsenic concentrations (12 ± 3 µg g−1) than mangrove leaves, bark or main roots (0.3–1.2 µg g−1) and algae/fungi attached to main roots (1.5 ± 0.8 µg g−1). The concentrations of arsenic in detritivores (8.5–55 µg g−1) were significantly higher than in the major primary producers (0.3–1.5 µg g−1), two herbivores (8 ± 1 and 14 ± 2 µg g−1) and omnivores (2–16.6 µg g−1). Most marine animal tissues contained large percentages of arsenobetaine (28–81%). Glycerol arsenoribose was found in all tissues examined (1–23%) except oyster tissues. Relatively large concentrations of this arsenoriboside were found in the digestive tissues of two crab species (13–23%). Small amounts of trimethylarsoniopropionate (1–8%), tetramethylarsonium ion (1–7%), sulfate arsenoribose (2–13%) and trace amounts of arsenocholine (<1%), trimethylarsine oxide (<1%), dimethylarsinic acid (<2%), phosphate arsenoribose (<2%), arsenate (<1%), and sulfonate arsenoribose (<3%) were found in some tissues. Methylarsonic acid was not found in any tissues. Two unknown cationic arsenic compounds (1–2%) and three anionic arsenic compounds (1–17%) were present in some marine animal tissues. The arsenic concentrations and species found in animals could not be attributed to their position in the food web or feeding mode, but are likely to be related to their dietary intake of arsenic and their ability to assimilate, metabolize and retain arsenic species. Copyright © 2002 John Wiley & Sons, Ltd.
Biomethylation of bismuth by the methanogen Methanobacterium formicicum
Authors: Michalke Klaus , Meyer Jörg , Hirner Alfred V. , Hensel Reinhard 
Published: August 2002

AbstractIn this study the bioconversion of bismuth to volatile derivatives was investigated in cultures of the common sewage sludge methanogen Methanobacterium formicicum. The production of volatile bismuth compounds was analysed during growth of M. formicicum with respect to the concentration and chemical formulation of the applied bismuth. The main volatile bismuth compound detected in the culture headspace was trimethylbismuth (TMBi), with a maximum conversion rate of up to 2.6 ± 1.8% from spiked 1 µM bismuth nitrate [Bi(NO3)3] in the culture media. This main compound proved to be stable under the incubation conditions in a CO2–H2 atmosphere. Bismuthine and the partially methylated bismuthines monomethylbismuth hydride and dimethylbismuth hydride were additionally detected in the late exponential growth phase, but only in the presence of low concentrations of spiked Bi(NO3)3 (10 nM, 100 nM). The conversion of bismuth to TMBi from the bismuth‐containing pharmaceuticals Bismofalk® [containing bismuth subgallate and Bi(NO3)3] and Noemin® (containing bismuth aluminate) could also be observed, however, with a lower rate than found for Bi(NO3)3. In vitro experiments with crude extracts of M. formicicum suggest that the methylation of bismuth is mainly catalysed by enzyme‐catalysed reactions with methylcobalamin as methyl donor. Copyright © 2002 John Wiley & Sons, Ltd.
Thermal cure monitoring of phenolic resole resins based on in situ fluorescence technique
Authors: Vatanparast Ramin , Li Shuyan , Hakala Kati , Lemmetyinen Helge 
Published: August 2002

AbstractThe thermal curing reaction of two phenolic resole resins is monitored using the fluorescence technique. The intrinsic fluorescence can be used as an indicator for cure monitoring for the first resole. As the thermal curing proceeds, the intrinsic fluorescence intensity of the resole resin decreases and exhibits a few nanometers of redshift. The fluorescence intensity of the emission maxima is correlated with the conversion measured by differential scanning spectroscopy. A linear correlation is found at three different temperatures. The intrinsic fluorescence cannot always be used for monitoring the curing process of phenolic resole resins. Thus, three intramolecular charge transfer compounds and two organic donor–π‐acceptor salts are selected and applied for the cure monitoring of the second phenolic resole resin. As the curing reaction proceeds, the fluorescence emission spectra of the probes exhibit a blue spectral shift and the intensity changes because of environmental changes. An intensity ratio method is applied in which the ratios of the low‐ to high‐intensity changes in the emission bands are used to determine the degree of the curing process. There is a smooth correlation between the intensity ratio method and the degree of cure. The method enables one to follow the changes in the polymer structure at low and intermediate degrees of the curing process (below 70%) and obtain comparable results from different types of probes during the same curing process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1773–1780, 2002
Microporous membranes of isotactic poly(4‐methyl‐1‐pentene) from a melt‐extrusion process. I. Effects of resin variables and extrusion conditions
Authors: Johnson Matthew B. , Wilkes Garth L. 
Published: August 2002

AbstractA study utilizing isotactic poly(4‐methyl‐1‐pentene) (PMP) was undertaken to investigate a three‐stage process (melt‐extrusion/annealing/uniaxial‐stretching) (MEAUS) employed to produce microporous films. The results of this study will be reported in the course of two articles. In this first part, three PMP resins were melt‐extruded into tubular films (blowup ratio; BUR = 1), where the resins each differ in weight‐average molecular weight (Mw). Specific attention was focused upon the morphological and crystal orientation results as a function of the melt‐relaxation times as influenced by the resin characteristics and the processing parameters. The results of a number of melt‐extrusion conditions are presented. A stacked lamellar morphology was obtained in each case; however, the type of stacked lamellar morphology, planar or twisted, and the orientation state was found to depend upon both the resin characteristics, specifically Mw, and the melt‐extrusion conditions. Atomic force microscopy and wide‐angle X‐ray scattering (WAXS) were the main techniques utilized to study the melt‐extruded films, while oscillatory shear measurements, in conjunction with a Carreau–Yasuda analysis, aided in differentiating the melt‐flow behavior of the three resins. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2095–2113, 2002
Iron(III) ion removal from solution through adsorption on chitosan
Authors: Burke A. , Yilmaz E. , Hasirci N. , Yilmaz O. 
Published: August 2002

AbstractThe potential of different forms of chitosan to adsorb iron(III) ion from a Jectofer [an iron(III)–sorbitol–citric acid complex] solution was investigated. The working solution was chosen as Jectofer, to mimic the composition of excess iron(III) as may be found in biological systems. The equilibrium studies showed that chitosan powder has the highest sorption capacity for the iron(III) ion when compared to chitosan flakes and microspheres. The amount of iron(III) adsorbed onto chitosan was found to increase with the contact time to reach equilibrium within 3 h at 37°C. A higher initial concentration of a Jectofer solution resulted in a higher amount of iron(III) adsorbed. Higher pH values, in the range 2–7, also resulted in an increase in iron(III) uptake from the solution. The data of adsorption from the Jectofer solution were found to correlate well with the Freundlich isotherm equation. In vitro adsorption experiments showed that chitosan is capable of adsorbing excess iron, measured in terms of the ferritin level, in human blood. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1185–1192, 2002; DOI 10.1002/app.10416
Three‐dimensionally braided carbon fiber–epoxy composites, a new type of material for osteosynthesis devices. I. Mechanical properties and moisture absorption behavior
Authors: Wan Y. Z. , Wang Y. L. , Cheng G. X. , Han K. Y. 
Published: August 2002

AbstractIn recent years, three‐dimensionally (3D) braided composites have attracted a great deal of attention because of their high‐impact damage tolerance and fatigue life, superior fracture toughness, and so forth, and have been used in aeronautics, military, and transportation. These advantages make them strong candidates for osteosynthesis devices. In this study, 3D braided carbon fiber–epoxy (C3D/EP) composites were produced via a simple vacuum impregnation technique. The load‐deflection curve, mechanical properties, and influence of fiber volume fraction, braiding angle, and axial reinforcing fibers were examined to determine their suitability for internal fixation devices. It is found that the C3D/EP composites have excellent toughness and do not show brittleness when fractured because of their relatively high void content. The flexural, shear, and impact strengths of the C3D/EP composites are excellent. It was shown that a C3D/EP composite with a stiffness similar to load‐bearing bones can be made while maintaining enough strength. It is concluded that a relatively higher void content and braiding angle is more suitable for the C3D/EP composites from the viewpoint of requirements of fracture fixation materials. The moisture absorption behavior and changes in mechanical properties caused by moisture uptake were evaluated. Results show that absorbed moisture slightly decreases mechanical properties of the C3D/EP composites. Contrary to the unreinforced epoxy, the moisture absorption behavior of the C3D/EP composites cannot be described with Fick's law of diffusion, probably because of the presence of voids and/or 3D fiber structure. The exact mechanisms should be proposed in further investigations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1031–1039, 2002
Physical and mechanical properties of polyethylene for pipes in relation to molecular architecture. II. Short‐term creep of isotropic and drawn materials
Authors: Hubert L. , David L. , Séguéla R. , Vigier G. , Corfias‐Zuccalli C. , Germain Y. 
Published: August 2002

AbstractTensile drawing and short‐term creep of ethylene/α‐olefin copolymers having bimodal (BM) molar weight distribution are studied in comparison with unimodal (UM) copolymers of similar crystallinity. The natural draw ratio and viscoelastic recovery upon unloading strongly suggest that BM copolymers have more tie chains and chain entanglements than corresponding UM copolymers. The incorporation of co‐units in the longest chains of BM copolymers is ascribed a major role on these topological changes. Creep of isotropic materials shows lower compliance for BM copolymers in parallel with higher‐durability grades. This is attributed to a better “macromolecular network efficiency.” The creep behavior of strain‐hardened samples, which is assumed to simulate the mechanical behavior of craze fibrils at the tip of a propagating crack, reveals similar trends. The better fibril strength in BM copolymers is again ascribed to a better network efficiency. Necked samples display an odd behavior of higher compliance at low stress and lower compliance at high stress for BM copolymers compared with the behavior of UM counterparts. This is associated with the exhaustion of viscoelastic capabilities with increasing draw ratio and stress. The phenomenon is discussed in relation to cavitation. A short‐term creep test is proposed for comparative prediction of long‐term behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2308–2317, 2002