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Various Sizes (various + size)
Selected AbstractsPopulation Size, Genetic Variation, and Reproductive Success in a Rapidly Declining, Self-Incompatible Perennial (Arnica montana) in The NetherlandsCONSERVATION BIOLOGY, Issue 6 2000Sheila H. Luijten In 26 populations in The Netherlands we investigated the relationship between population size and genetic variation using allozyme markers. Genetic variation was low in A. montana ( He = 0.088). There were positive correlations between population size and the proportion of polymorphic loci, the number of effective alleles, and expected heterozygosity, but not with observed heterozygosity. There was a significantly positive correlation between population size and the inbreeding coefficient. Generally, small populations showed heterozygote excess, which decreased with increasing population size. Possibly, the heterozygous individuals in small populations are survivors from the formerly larger populations with relatively high fitness. The F statistics showed a moderately high level of differentiation among populations ( FST = 0.140 ± 0.02), implying a low level of gene flow. For three out of four allozyme loci, we found significant inbreeding ( FIS = 0.104 ± 0.03). Only 14 of 26 populations were in Hardy-Weinberg equilibrium at all four polymorphic loci. In a subset of 14 populations of various size, we investigated natural seed production and offspring fitness. Population size was positively correlated with seed set, seedling size, number of flowering stems and flowerheads, adult survival, and total relative fitness, but not with the number of florets per flowerhead, germination rate, or the proportion of germination. Offspring performance in the greenhouse was not associated with genetic diversity measured on their mothers in the field. We conclude that the fitness of small populations is significantly reduced, but that there is as yet no evidence that this was caused by inbreeding. Possibly, the self-incompatibility system of A. montana has been effective in reducing selfing rates and inbreeding depression. Resumen:Arnica montana es una especie de planta rara, en declinación rápida y autoincompatible. En 26 poblaciones de los Países Bajos investigamos la relación entre el tamaño poblacional y la variación genética mediante el uso de alozimas marcadoras. La variación genética fue baja en A. montana ( He = 0.088). Existió una correlación positiva entre el tamaño poblacional y la proporción de emplazamientos polimórficos, el número de alelos efectivos y la heterocigocidad esperada, pero no con la heterocigocidad observada. Existió una correlación positiva significativa entre el tamaño poblacional y el coeficiente de endogamia. Generalmente, las poblaciones pequeñas mostraron una heterocigocidad excesiva con disminuciones en el tamaño poblacional. Posiblemente, los individuos heterocigóticos de poblaciones pequeñas son sobrevivientes de poblaciones anteriormente grandes con una adaptabilidad relativamente alta. Las pruebas de F mostraron un nivel de diferenciación moderadamente alto entre poblaciones ( FST = 0.140 ± 0.02) lo que implica un nivel bajo de flujo de genes. Para tres de cuatro de los emplazamientos de alozimas encontramos una endogamia significativa ( FIS = 0.104 ± 0.03). Solamente 14 de las 26 poblaciones estuvieron en equilibrio Hardy-Weinberg para los cuatro emplazamientos polimórficos. En un subconjunto de 14 poblaciones de varios tamaños, investigamos la producción natural de semillas y la adaptabilidad de la descendencia. El tamaño poblacional estuvo positivamente correlacionado con el juego de semillas, el tamaño del almácigo, el número de tallos en flor y de inflorescencias, la supervivencia de adultos y la adaptabilidad total relativa, pero no con el número de flores por inflorescencia, la tasa de germinación ni la proporción de la germinación. El rendimiento de la descendencia en invernaderos no estuvo asociado con la diversidad genética medida en sus madres en el campo. Concluimos que la adaptabilidad de poblaciones pequeñas está significativamente reducida, pero no existe aún evidencia de que esto sea ocasionado por endogamia. Es posible que el sistema de autoincompatibilidad de A. montana haya sido efectivo en la reducción de tasas de autofecundación y depresión de la endogamia. [source] Highly Robust Estimation of the Autocovariance FunctionJOURNAL OF TIME SERIES ANALYSIS, Issue 6 2000Yanyuan Ma In this paper, the problem of the robustness of the sample autocovariance function is addressed. We propose a new autocovariance estimator, based on a highly robust estimator of scale. Its robustness properties are studied by means of the influence function, and a new concept of temporal breakdown point. As the theoretical variance of the estimator does not have a closed form, we perform a simulation study. Situations with various size of outliers are tested. They confirm the robustness properties of the new estimator. An S-Plus function for the highly robust autocovariance estimator is made available on the Web at http://www-math.mit.edu/~yanyuan/Genton/Time/time.html. At the end, we analyze a time series of monthly interest rates of an Austrian bank. [source] Bilateral tibialis anterior muscle herniation simulating a soft tissue tumour in a young amateur football playerAUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 2 2010Ali Murat Ceyhan ABSTRACT Muscle herniation is a focal protrusion of muscle tissue through a defect in the deep fascial layer. Anterior tibial muscle is the most commonly affected muscle of the lower extremities because its fascia is the most vulnerable to trauma. Clinically it is characterized by asymptomatic or painful, skin-coloured, soft, subcutaneous nodules of various size depending on the position. The diagnosis is usually made clinically based on its typical manifestations, but ultrasonographic examination is useful for detecting the fascial defect and excluding other conditions caused by soft tissue tumours such as lipomas, angiolipomas, fibromas, scwhannomas or varicosities. Although this entity is not rare, it has been less well documented in the dermatological literature. We report a case of bilateral tibialis anterior muscle herniation mimicking a soft tissue tumour in a young amateur football player. [source] Multiple Conceptualizations of Small Business Web Use and Benefit*DECISION SCIENCES, Issue 3 2003Kurt A. Pflughoeft ABSTRACT Small businesses play an important role in the U.S. economy and there is anecdotal evidence that use of the Web is beneficial to such businesses. There is, however, little systematic analysis of the conditions that lead to successful use of and thereby benefits from the Web for small businesses. Based on the innovation adoption, organizations, and information systems (IS) implementation literature, we identify a set of variables that are related to adoption, use, and benefits of information technology (IT), with particular emphasis on small businesses. These variables are reflective of an organization's contextual characteristics, its IT infrastructure, Web use, and Web benefits. Since the extant research does not suggest a single theoretical model for Web use and benefits in the context of small businesses, we adopt a modeling approach and explore the relationships between "context-IT-use-benefit" (CIUB) through three models,partial-mediator, reduced partial-mediator, and mediator. These models posit that the extent of Web use by small businesses and the associated benefits are driven by organizations' contextual characteristics and their IT infrastructure. They differ in the endogeneity/exogeneity of the extent of IT sophistication, and in the direct/mediated effects of organizational context. We examine whether the relationships between variables identified in the literature hold within the context of these models using two samples of small businesses with national coverage, including various sizes, and representing several industry sectors. The results show that the evidence for patterns of relationships is similar across the two independent samples for two of these models. We highlight the relationships within the reduced partial-mediator and mediator models for which conclusive evidence are given by both samples. Implications for small business managers and providers of Web-based technologies are discussed. [source] Liesegang rings in fine needle aspirate of breast cysts with predominance of apocrine cells: A study of 14 casesDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2008F.I.A.C., Raj K. Gupta M.D. Abstract Fine needle aspirate (FNA) from 14 cases (age range 17,84 years), with Liesegang rings (LR's) in breast cysts seen over a period of 26 years comprised the material of this study from more than 38,000 FNA's of the breast which had been done for a variety of breast lesions. In six of the 14 cases, the aspirate was obtained under ultrasound guidance whereas in the remaining cases it was collected from a palpable lesion. The aspiration was performed using a 22 gauge needle and the syringe and needle contents were washed in a cytology container with 30% ethyl alcohol in physiologic saline. The cytologic preparations from half of the sample were made on a 5 micron Schleicher and Schuell filter and stained by Papanicolaou method whereas from the remainder of the sample a cell block was made and sections cut, stained with hematoxylin-eosin (H&E) and used for immunohistochemical study. Filter preparations and cell blocks revealed cyanophilic, spherical, ring-like structures of various sizes and shape mostly with double walls, and striations with amorphous material in the lumen and under polarized light were nonrefractile. Seen also were several apocrine cells and some macrophages and the LR's were found to be negative on immunostains for EMA and CK, and a panel of other special stains (Table I). Since LR's can be mistaken for ova, larvae, or parasites, it is important to be aware of their potential presence in aspirate samples of breast cysts to avoid a misdiagnosis. The exact mechanism of formation of LR's is not fully understood and certain views as proposed are discussed in this presentation. Diagn. Cytopathol. 2008;36:701,704. © 2008 Wiley-Liss, Inc. [source] Combining information from range use and habitat selection: sex-specific spatial responses to habitat fragmentation in tawny owls Strix alucoECOGRAPHY, Issue 2 2006Peter Sunde How individuals respond to habitat heterogeneity is usually measured as variation in range size and by ranking the relative importance of habitat types (habitat selection). The combined effect of how individuals incorporate different habitat types in their home ranges and allocate their time budget between them is rarely derived. Additionally, when home range size varies between individuals, habitat selection analyses might be flawed if foraging decisions are based on variation in absolute rather than proportional availability. We investigated the suitability of standard analytical approaches by measuring the spatial responses of tawny owls to habitat fragmentation. These owls inhabited woodland of various sizes, representing a fragmentation gradient from open farmland with small, isolated woodland patches, to continuous woodland within their home ranges. In 17 territories within open farmland, the available area covered by woodland increased with the square root of the area of open land embraced in the home range. The owls did not display functional response in habitat selection, but females selected woodland more strongly than males. Females utilised woodland 10 times more intensively in farmland than in continuous woods, whereas males utilised farmland woods 3.2 times more intensively. Moreover, females in farmland exploited woodland 3.2 times as intensively as males, apparently because of higher travel costs in open areas. Since the extensive variation in intensity of use as a function of total availability was not indicated from the analysis of habitat selection, we suggest that information about intensity of use be more widely used as a supplementary measure of habitat use patterns than appears to be the practice at present. [source] Huntingtin inclusion bodies are iron-dependent centers of oxidative eventsFEBS JOURNAL, Issue 23 2006Wance J. J. Firdaus Recently, we reported that the transient expression of huntingtin exon1 polypeptide containing polyglutamine tracts of various sizes (httEx1-polyQ) in cell models of Huntington disease generated an oxidative stress whose intensity was CAG repeat expansion-dependent. Here, we have analyzed the intracellular localization of the oxidative events generated by the httEx1-polyQ polypeptides. Analysis of live COS-7 cells as well as neuronal SK-N-SH and PC12 cells incubated with hydroethidine or dichlorofluorescein diacetate revealed oxidation of these probes at the level of the inclusion bodies formed by httEx1-polyQ polypeptides. The intensity and frequency of the oxidative events among the inclusions were CAG repeat expansion-dependent. Electron microscopic analysis of cell sections revealed the presence of oxidation-dependent morphologic alterations in the vicinity of httEx1-polyQ inclusion bodies. Moreover, a high level of oxidized proteins was recovered in partially purified inclusions. We also report that the iron chelator deferroxamine altered the structure, localization and oxidative potential of httEx1-polyQ inclusion bodies. Hence, despite the fact that the formation of inclusion bodies may represent a defense reaction of the cell to eliminate httEx1 mutant polypeptide, this phenomenon appears inherent to the generation of iron-dependent oxidative events that can be deleterious to the cell. [source] Bigger is better: implications of body size for flight ability under different light conditions and the evolution of alloethism in bumblebeesFUNCTIONAL ECOLOGY, Issue 6 2007A. KAPUSTJANSKIJ Summary 1In social insects, reproductive success and survival of the colony critically depend on the colony's ability to efficiently allocate workers to the various tasks which need to be performed. In bumblebees, workers show a large variation of body size within a colony. Large workers tend to leave the nest and forage for nectar and pollen, whereas small workers stay inside the nest and fulfill nest duties. It was speculated that size-related differences of the sensory system might contribute to alloethism found in bumblebee colonies. 2In the first part, we investigated how body size determines eye morphology. We measured several eye parameters of Bombus terrestris workers and drones. In both, workers and drones, larger individuals had larger eyes with larger facet diameters, more ommatidia and larger ocelli. At similar body size, drones exhibited larger eyes and ocelli compared to workers. Due to theoretical considerations, we predict that large individuals with large eyes should be better able to operate in illumination conditions of lower intensity than small individuals, since ommatidial sensitivity is proportional to the square of facet diameter. 3In the second part, we tested this prediction. In a behavioural experiment, we first caught bumblebees of various sizes in the field and then determined the lowest light intensity level at which they are just able to fly under controlled laboratory conditions. We tested workers of B. terrestris and B. pascuorum, and workers and drones of B. lapidarius. Large bumblebees were able to fly under lower light levels compared to small bees, with light intensity thresholds ranging from 1·1 to 5·5 lux. 4Our results indicate that the increased light sensitivity of the visual system of large bumblebees allows them to fly under poor light conditions, for example, very early in the morning or late at dusk. This is of potential benefit to the survival of a bumblebee colony since flowers that open early in the morning usually have accumulated a relatively high amount of nectar and pollen throughout the night, and large bumblebees can utilize these resources earlier than most other bees. Thus, our findings have important implications for the understanding of the functional significance and evolution of alloethism in bumblebee colonies. [source] Shrink-Induced Nanowrinkles: Tunable Nanowrinkles on Shape Memory Polymer Sheets (Adv. Mater.ADVANCED MATERIALS, Issue 44 200944/2009) By leveraging the mismatch in stiffness between a stiff thin metal film and heat-induced shrinkage of prestressed polystyrene sheets, Michelle Khine and co-workers can rapidly and controllably create tunable nanowrinkles of various sizes and shapes for surface-enhanced sensing applications, as reported on p. 4472. Because the wrinkles are robustly embedded into the plastic, nanostructures can be integrated into microfluidic channels within minutes. Cover design by Libre Design. [source] A random field model for generating synthetic microstructures of functionally graded materialsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2008Sharif Rahman Abstract This article presents a new level-cut, inhomogeneous, filtered Poisson random field model for representing two-phase microstructures of statistically inhomogeneous, functionally graded materials with fully penetrable embedded particles. The model involves an inhomogeneous, filtered Poisson random field comprising a sum of deterministic kernel functions that are scaled by random variables and a cut of the filtered Poisson field above a specified level. The resulting level-cut field depends on the Poisson intensity, level, kernel functions, random scaling variables, and random rotation matrices. A reconstruction algorithm including model calibration and Monte Carlo simulation is presented for generating samples of two-phase microstructures of statistically inhomogeneous media. Numerical examples demonstrate that the model developed is capable of producing a wide variety of two- and three-dimensional microstructures of functionally graded composites containing particles of various sizes, shapes, densities, gradations, and orientations. An example involving finite element analyses of random microstructures, leading to statistics of effective properties of functionally graded composites, illustrates the usefulness of the proposed model. Copyright © 2008 John Wiley & Sons, Ltd. [source] Small and large anemonefishes can coexist using the same patchy resources on a coral reef, before habitat destructionJOURNAL OF ANIMAL ECOLOGY, Issue 5 2002Akihisa Hattori Summary 1According to meta-population models, a superior competitor and a superior disperser can coexist in a patchy environment. The two anemonefishes, a large aggressive Amphiprion clarkii Bennett and a small less-aggressive A. perideraion Bleeker, use the same host anemone Heteractis crispa Ehrenberg on a coral reef, Okinawa, Japan, where most of the hosts disappeared after the coral bleaching in 1998. Their microhabitat (host) use and coexistence, and the quality and quantity of microhabitats were investigated in 1988, 1989, 1999 and 2000 on the coral reef. Their interspecific interaction was also examined. 2Before the habitat destruction, the two species coexisted. Although A. clarkii was behaviourally dominant over A. perideraion in a cohabiting group, A. perideraion was a superior competitor in terms of site displacement, because A. perideraion could displace a microhabitat. Adult A. clarkii emigrated from a cohabiting group probably due to the high cost of interactions with adult A. perideraion . Although it is easier to defend a small area for a larger species, sharing a host with adult A. perideraion may not pay for A. clarkii because A. clarkii needs a larger area. 3A. clarkii was not only a superior disperser, which was able to find a vacated host, but also a pioneer species that was able to use newly settled small hosts. Larval A. clarkii settled on such a small host because they were able to move to larger hosts for future reproduction, while A. perideraion did not settle on a small host because of low mobility after settlement. Microhabitat (host) with various sizes might have promoted their coexistence. 4After the habitat destruction, the superior competitor A. perideraion went extinct locally due probably to lack of small host utilization ability. The present study implies that the difference in body size between the two competitors plays an important role in their coexistence, because species with different body sizes can have different mobility and require different amounts of resources. [source] Effect of precipitate size and dispersion on recrystallization behavior in Ti-added ultra low carbon steelsJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2003E. J. Shin The effect of coiling temperature on precipitates and solid solution was investigated in P-free and P-added Ti-stabilized ultra low carbon steels. The volume fractions of the fine precipitates smaller than 60 nm were evaluated by using small-angle neutron scattering technique. The solute P was quantified from the lattice parameters obtained from neutron diffraction patterns. In the P-free steels, TiC and Ti4C2S2 with various sizes ranging from 5~60 nm were observed. In addition to these precipitates, FeTiP precipitates of a size exceeding 50 nm were also observed in the P-added steel. The amount of fine precipitates smaller than 10 nm and the concentration of solute P was higher in the samples coiled at low temperature. The recrystallization temperature increases if the coiling temperature decreases in both, P-free and P-added steels. The recrystallization temperature of P-free steels is lower than that of P-added steels. In the P-free steels, the pinning effect of fine precipitates played a key role for the retardation of the recrystallization. In the P-added steels, the retardation of recrystallization is due to both, the pinning effect of fine precipitates and the solute drag effect of P in solid solution. [source] Characteristic modeling of the wear particle formation process from a tribological testing of polyethylene with controlled surface asperitiesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Hsu-Wei Fang Abstract To study the ultra-high molecular weight polyethylene (UHMWPE) wear particles-induced osteolysis which leads to the failure of artificial joints, microfabricated surfaces with controlled asperities have been applied to generate narrowly distributed UHMWPE wear particles with various sizes and shapes. Our previous study further facilitated single wedge sliding tests to investigate the mechanism of the UHMWPE particle generation. In this study, the attempt was made to characterize the particle generation process into a mathematical model to predict particle volume with a given surface-texture dimensions and mechanical loading conditions. The particle-generation process is decomposed into two steps: (1) penetration of the cutting edge, and (2) lateral sliding of the cutting edge. By combining the indentation experimental data, the viscoelastic responses of UHMWPE was incorporated in the model. The effects of normal load, feature height, and cutting edge angle on the wear particle volume were illustrated from model predictions. Both experimental results and model predictions indicate the same trend of effects of surface-texture geometry and mechanical conditions on the volume of particles. The results of the model predictions are close to the experimental results of the particle generation. However, the particle volume predicted by the model is larger than the experimental results. It is believed that the reprocessing of the generated particles and viscoelastic recovery of UHMWPE in the experiments account for this difference. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 587,594, 2007 [source] Bigger is better: the influence of physical size on aesthetic preference judgmentsJOURNAL OF BEHAVIORAL DECISION MAKING, Issue 3 2002David H. Silvera Abstract The hypothesis that the physical size of an object can influence aesthetic preferences was investigated. In a series of four experiments, participants were presented with pairs of abstract stimuli and asked to indicate which member of each pair they preferred. A preference for larger stimuli was found on the majority of trials using various types of stimuli, stimuli of various sizes, and with both adult and 3-year-old participants. This preference pattern was disrupted only when participants had both stimuli that provided a readily accessible alternative source of preference-evoking information and sufficient attentional resources to make their preference judgments. Copyright © 2002 John Wiley & Sons, Ltd. [source] Enhanced docking with the mining minima optimizer: Acceleration and side-chain flexibilityJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 16 2002Visvaldas Kairys Abstract The ligand,protein docking algorithm based on the Mining Minima method has been substantially enhanced. First, the basic algorithm is accelerated by: (1) adaptively determining the extent of each energy well to help avoid previously discovered energy minima; (2) biasing the search away from ligand positions at the surface of the receptor to prevent the ligand from staying at the surface when large sampling regions are used; (3) quickly testing multiple different ligand positions and orientations for each ligand conformation; and (4) tuning the source code to increase computational efficiency. These changes markedly shorten the time needed to discover an accurate result, especially when large sampling regions are used. The algorithm now also allows user-selected receptor sidechains to be treated as mobile during the docking procedure. The energies associated with the mobile side chains are computed as if they belonged to the ligand, except that atoms at the boundary between side chains and the rigid backbone are treated specially. This new capability is tested for several well-known ligand/protein systems, and preliminary application to an enzyme whose substrate is unknown,the recently solved hypothetical protein YecO (HI0319) from Haemophilus influenzae,indicates that side-chains relaxations allow candidate substrates of various sizes to be accommodated. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1656,1670, 2002 [source] The effects of neighbouring tree islands on pollinator density and diversity, and on pollination of a wet prairie species, Asclepias lanceolata (Apocynaceae)JOURNAL OF ECOLOGY, Issue 3 2006DEREK R. ARTZ Summary 1The Everglades (Florida, USA) is a mosaic of different habitats. Tropical and temperate trees grow on patches of high ground (tree islands) surrounded by lower elevation wetland communities (marl prairie). 2Tree islands of various sizes provide nesting substrate, larval host plants and floral resources for insect pollinators. Herbaceous plants in the open surrounding wetlands may also depend on these pollinators. 3We investigated pollinator diversity and abundances in both tree island and marl prairie habitats using transect sampling methods and estimated pollination success of the milkweed Asclepias lanceolata, an insect-pollinated marl prairie species, in relation to distance from and size of the closest tree island. 4On a total of 11 bayhead tree islands, we found that insect diversity and abundance were greater on the edge of larger tree islands (20,30 m2) than on smaller tree islands (5,10 m2). Pollinator diversity and abundance in the marl prairie decreased with increasing distance from tree islands. 5Pairs of potted A. lanceolata plants were placed in the marl prairie at distances up to 1000 m from small and large tree islands. Fruit and seed production were highest for plants placed less than 25 m from tree islands and decreased with increasing distance. 6Our results suggest that tree islands are an important source of pollinators for the plants in the tree island and surrounding wetland habitats. 7This landscape-based study illustrates how overall landscape structure affects important biotic interactions, particularly plant,pollinator relationships. Our findings have far-reaching ecological implications for the reproductive success of plants in small, isolated populations that may depend on insect vectors for pollination. [source] Effects of Size of Cellulose Granules on Dough Rheology, Microscopy, and Breadmaking PropertiesJOURNAL OF FOOD SCIENCE, Issue 2 2007M. Seguchi ABSTRACT:, Breadmaking was performed with cellulose-blended wheat flour. Cellulose granules (7 types) of various sizes (diameter) were prepared by kneading. With increase of the blend percent of the cellulose samples from 10% to 20%, breadmaking properties such as bread height and specific volume (SV) gradually decreased in every sample; however, the decreasing levels of the properties in 7 types of various sizes varied. The decrease of bread height and SV was associated with the size of the cellulose granule. It was observed at both 10% and 20% blends that the same bread height and SV as for bread baked with only wheat flour could be obtained when the diameter of cellulose granule was above 154 ,m in cellulose/wheat flour breadmaking, while they gradually decreased with granules below 154 ,m. When the largest cellulose granules were mechanically ground to make smaller ones, the bread height and SV decreased with increasing grinding time. It was ascertained that the size of the cellulose granule was important for breadmaking properties. Cellulose-blended wheat flour was subjected to mixograph tests. When cellulose granules above 154-,m dia were blended with wheat flour, the profile of the mixogram was almost the same as that for wheat flour; that is, the profile had a short mixing requirement and showed a viscous gluten matrix. However, when cellulose granules below 81-,m dia were blended, a different curve showing a nonviscous dough due to breakdown of the gluten protein was observed, as ascertained by microscopy. Farmograph test showed that the amount of the released gas from cellulose-blended bread dough increased with decrease of the size of the cellulose granule due to breakdown of the gluten protein. [source] Sexual Dimorphism in America: Geometric Morphometric Analysis of the Craniofacial Region,JOURNAL OF FORENSIC SCIENCES, Issue 1 2008Erin H. Kimmerle Ph.D. Abstract:, One of the four pillars of the anthropological protocol is the estimation of sex. The protocol generally consists of linear metric analysis or visually assessing individual skeletal traits on the skull and pelvis based on an ordinal scale of 1,5, ranging from very masculine to very feminine. The morphologic traits are then some how averaged by the investigator to estimate sex. Some skulls may be misclassified because of apparent morphologic features that appear more or less robust due to size differences among individuals. The question of misclassification may be further exemplified in light of comparisons across populations that may differ not only in cranial robusticity but also in stature and general physique. The purpose of this study is to further examine the effect of size and sex on craniofacial shape among American populations to better understand the allometric foundation of skeletal traits currently used for sex estimation. Three-dimensional coordinates of 16 standard craniofacial landmarks were collected using a Microscribe-3DX digitizer. Data were collected for 118 American White and Black males and females from the W.M. Bass Donated Collection and the Forensic Data Bank. The MANCOVA procedure tested shape differences as a function of sex and size. Sex had a significant influence on shape for both American Whites (F = 2.90; d.f. = 19, 39; p > F = 0.0024) and Blacks (F = 2.81; d.f. = 19, 37; p > F = 0.0035), whereas size did not have a significant influence on shape in either Whites (F = 1.69; d.f. = 19, 39; p > F = 0.08) or Blacks (F = 1.09; d.f. = 19, 37; p > F = 0.40). Therefore, for each sex, individuals of various sizes were statistically the same shape. In other words, while significant differences were present between the size of males and females (males on average were larger), there was no size effect beyond that accounted for by sex differences in size. Moreover, the consistency between American groups is interesting as it suggests that population differences in sexual dimorphism may result more from human variation in size than allometric variation in craniofacial morphology. [source] Expression of multiple AQP4 pools in the plasma membrane and their association with the dystrophin complexJOURNAL OF NEUROCHEMISTRY, Issue 6 2008Grazia Paola Nicchia Abstract Altered aquaporin-4 (AQP4) expression has been reported in brain edema, tumors, muscular dystrophy, and neuromyelitis optica. However, the plasma membrane organization of AQP4 and its interaction with proteins such as the dystrophin-associated protein complex are not well understood. In this study, we used sucrose density gradient ultracentrifugation and 2D blue native/sodium dodecyl sulfate,polyacrylamide gel electrophoresis and showed the expression of several AQP4 multi-subunit complexes (pools) of different sizes, ranging from , 1 MDa to ,500 kDa and containing different ratios of the 30/32 kDa AQP4 isoforms, indicative of orthogonal arrays of particles of various sizes. A high molecular weight pool co-purified with dystrophin and ,-dystroglycan and was drastically reduced in the skeletal muscle of mdx3cv mice, which have no dystrophin. The number and size of the AQP4 pools were the same in the kidney where dystrophin is not expressed, suggesting the presence of dystrophin-like proteins for their expression. We found that AQP2 is expressed only in one major pool of ,500 kDa, indicating that the presence of different pools is a peculiarity of AQP4 rather than a widespread feature in the AQP family. Finally, in skeletal muscle caveolin-3 did not co-purify with any AQP4 pool, indicating the absence of interaction of the two proteins and confirming that caveolae and orthogonal arrays of particles are two independent plasma membrane microdomains. These results contribute to a better understanding of AQP4 membrane organization and raise the possibility that abnormal expression of specific AQP4 pools may be found in pathological states. [source] Viability of fibroblasts in cell culture after treatment with different chemical retraction agentsJOURNAL OF ORAL REHABILITATION, Issue 1 2002I. Kopa Prior to fixed prosthodontic impression procedures, temporary horizontal retraction of the free gingival tissue should be accomplished apically to the preparation finishing line. The mechanical,chemical method using cotton retraction cords of various sizes impregnated with various retraction chemicals is the most commonly employed retraction technique. Most retraction agents have pH values from 0·8 to 0·3, and are therefore hazardous to the cut dentine and periodontal tissues. Sympathomimetic vasoconstrictors introduced recently have a pH of 5·6, and are free of systemic side-effects. The present study using the dye exclusion test, colony forming ability test and colorimetric assay was undertaken to evaluate cytotoxic effects of four chemical retraction agents on cultured V-79 fibroblasts, and the dependence of cytotoxicity on the agent concentration and time of exposure. Original concentrations of retraction agents produced stronger cytotoxic effects than dilutions of 1:1 and 1:10. The most aggressive agent, 25% aluminium chloride, took only 1 min to damage all cell cultures. The proportion of cells damaged after 10 min of exposure to tetrahydrozoline was 60%, which was significantly less compared with other chemicals tested. With the colony forming ability test using retraction agents diluted to 1:10 the greatest number of colonies emerged in samples treated with tetrahydrozoline (statistical significance: P < 0·01). The colorimetric assay showed equal cytotoxic effects for 25% aluminium sulphate and tetrahydrozoline. The colorimetric test used in the study has proved an ergonomic, accurate and reliable test for cytotoxicity determination. [source] Stabilization of proteins by low molecular weight multi-ionsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2002Donald S. Maclean Abstract A method is described to identify small molecule ligands that stabilize proteins. The procedure is based on the hypothesis that molecules of various sizes containing two to four charges should occasionally bind to unpaired charged sites on the surface of proteins and by crosslinking such residues stabilize the native state of the liganded protein. A simple turbidity assay is employed that detects inhibition of protein aggregation under selected sets of conditions. Eight test proteins were screened and in all cases specific ligands were identified that inhibited protein aggregation at millimolar to micromolar concentrations. Only small effects of these stabilizers on protein biological activities were found. In some, but not all cases, circular dichroism and fluorescence studies provided direct evidence of the binding of stabilizing ligands to the proteins suggesting multiple mechanisms of stabilization. This approach should be applicable to the development of excipients for the stabilization of pharmaceutical proteins and industrial enzymes as well as serve as starting points for second-generation inhibitors of increased affinity and specificity. © 2002 Wiley-Liss Inc. and the American Pharmaceutical Association J Pharm Sci 91:2220,2229, 2002 [source] Synthesis of metal (Fe or Pd)/alloy (Fe,Pd)-nanoparticles-embedded multiwall carbon nanotube/sulfonated polyaniline composites by , irradiationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2006Kakarla Raghava Reddy Abstract Composites of multiwall carbon nanotubes (MWCNTs) and sulfonated polyaniline (SPAN) were prepared through the oxidative polymerization of a mixture of aniline, 2,5-diaminobenzene sulfonic acid, and MWCNTs. Fe, Pd, or Fe,Pd alloy nanoparticles were embedded into the MWCNT,SPAN matrix by the reduction of Fe, Pd, or a mixture of Fe and Pd ions with , radiation. Sulfonic acid groups and the emeraldine form of backbone units in SPAN served as the source for the reduction of the metal ions in the presence of , radiation. The existence of metallic/alloy particles in the MWCNT,SPAN matrix was further ascertained through characterization by high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy, ultraviolet,visible spectroscopy, thermogravimetric analysis, and conductivity measurements. HRTEM pictures clearly revealed the existence of Fe, Pd, and Fe,Pd nanoparticles of various sizes in the MWCNT,SPAN matrices. There were changes in the electronic properties of the MWCNT,SPAN,M composites due to the interaction between the metal nanoparticles and MWCNT,SPAN. Metal-nanoparticle-loaded MWCNT,SPAN composites (MWCNT,SPAN,M; M = Fe, Pd, or Fe,Pd alloy) showed better thermal stability than the pristine polymers. The conductivity of the MWCNT,SPAN,M composites was approximately 1.5 S cm,1, which was much higher than that of SPAN (2.46 × 10,4 S cm,1). Metal/alloy-nanoparticle-embedded, MWCNT-based composite materials are expected to find applications in molecular electronics and other fields. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3355,3364, 2006 [source] Raman spectra of benzoic acid enhanced by the silver nanoparticles of various sizesJOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2010K. H. Zheng Abstract Using sodium borohydride as the reducing agent and polyvinyl pyrrolidone (PVP, MW = 10 000) as the stabilizer, we obtained silver nanoparticles of various diameters (8,78 nm) from silver nitrate aqueous solutions in the concentration range from 0.001 to 0.1 M. The surface-enhanced Raman scattering (SERS) from benzoic acid's ring-breathing mode at 1003 cm,1 was detected from its dilute solutions (,10,2 M) doped with these silver nanoparticles under 488-nm laser excitation. The observed size dependences of SERS intensities fit quite well with those calculated by Schatz's theoretical model for spherical silver nanoparticles. The only exception occurred with the smallest particles (8 nm), possibly due to the failure of Maxwell's electromagnetic theory used in this model. Copyright © 2009 John Wiley & Sons, Ltd. [source] Engineering microporosity in bacterial cellulose scaffoldsJOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 6 2008Henrik Bäckdahl Abstract The scaffold is an essential component in tissue engineering. A novel method to prepare three-dimensional (3D) nanofibril network scaffolds with controlled microporosity has been developed. By placing paraffin wax and starch particles of various sizes in a growing culture of Acetobacter xylinum, bacterial cellulose scaffolds of different morphologies and interconnectivity were prepared. Paraffin particles were incorporated throughout the scaffold, while starch particles were found only in the outermost area of the resulting scaffold. The porogens were successfully removed after culture with bacteria and no residues were detected with electron spectroscopy for chemical analysis (ESCA) or Fourier transform infra-red spectroscopy (FT,IR). Resulting scaffolds were seeded with smooth muscle cells (SMCs) and investigated using histology and organ bath techniques. SMC were selected as the cell type since the main purpose of the resulting scaffolds is for tissue engineered blood vessels. SMCs attached to and proliferated on and partly into the scaffolds. Copyright © 2008 John Wiley & Sons, Ltd. [source] RFID tag antenna using two-shorted microstrip patches mountable on metallic objectsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2007Byunggil Yu Abstract A novel UHF band RFID tag antenna, which can be effectively mounted on metallic objects, is presented. Using the inductively coupled feeding technique, the proposed antenna consists of two symmetric shorted radiating elements and feeding loop. The feeding loop is excited so that the currents on the radiating elements are out of phase with the equal amplitude. The proposed tag antenna gives smaller variation of the antenna performance than that of conventional tag antennas when the tag is mounted on the various sizes of the metallic objects. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 414,416, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22159 [source] Study of the mouse sortilin gene: Effects of its transient silencing by RNA interference in TM4 sertoli cellsMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2004Jibin Zeng Abstract Using databases of the mouse genome in combination with a sequence deduced from a mouse sortilin cDNA originated in our laboratory, we found the sortilin gene to map to a region of chromosome 3. The mouse sortilin gene contains 19 short exons separated by introns of various sizes. The study elucidated the exon-intron boundaries. Some introns extend over more than 24 kb. In the cytoplasmic domain of the translation product, we found a dileucine motif and three other motifs known to constitute the active sorting signal of the mannose 6-phosphate receptor (M6P-R). We also tested the hypothesis that sortilin is involved in the sorting of prosaposin (SGP-1) to the lysosomes. Prosaposin was initially identified in Sertoli cells, found in large amounts in the lysosomal compartment and implicated in the degradation of residual bodies released by the spermatids during spermiation. Interestingly, the targeting of prosaposin to the lysosomes is independent of the M6P-R. This investigation demonstrated that sortilin was required for the trafficking of prosaposin to the lysosomes in TM4 cells. The requirement of sortilin was shown using a siRNA probe to block the translation of sortilin mRNA. Sortilin-deficient cells were not able to route prosaposin to the lysosomal compartment but continue to transport cathepsin B, since this hydrolase uses the M6P-R to be routed to the lysosomes. These results indicate that sortilin appears to be involved in the lysosomal trafficking of prosaposin. Mol. Reprod. Dev. 68: 469,475, 2004. © 2004 Wiley-Liss, Inc. [source] Galaxy groups in the Two-degree Field Galaxy Redshift Survey: the luminous content of the groupsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2004V. R. Eke ABSTRACT The Two-degree Field Galaxy Redshift Survey (2dFGRS) Percolation-Inferred Galaxy Group (2PIGG) catalogue of ,29 000 objects is used to study the luminous content of galaxy systems of various sizes. Mock galaxy catalogues constructed from cosmological simulations are used to gauge the accuracy with which intrinsic group properties can be recovered. It is found that a Schechter function is a reasonable fit to the galaxy luminosity functions in groups of different mass in the real data, and that the characteristic luminosity L, is slightly larger for more massive groups. However, the mock data show that the shape of the recovered luminosity function is expected to differ from the true shape, and this must be allowed for when interpreting the data. Luminosity function results are presented in both the bJ and rF wavebands. The variation of the halo mass-to-light ratio, ,, with group size is studied in both of these wavebands. A robust trend of increasing , with increasing group luminosity is found in the 2PIGG data. Going from groups with bJ luminosities equal to 1010 h,2 L, to those 100 times more luminous, the typical bJ -band mass-to-light ratio increases by a factor of 5, whereas the rF -band mass-to-light ratio grows by a factor of 3.5. These trends agree well with the predictions of the simulations which also predict a minimum in the mass-to-light ratio on a scale roughly corresponding to the Local Group. The data indicate that if such a minimum exists, then it must occur at L, 1010h,2 L,, below the range accurately probed by the 2PIGG catalogue. According to the mock data, the bJ mass-to-light ratios of the largest groups are expected to be approximately 1.1 times the global value. Assuming that this correction applies to the real data, the mean bJ luminosity density of the Universe yields an estimate of ,m= 0.26 ± 0.03 (statistical error only). Various possible sources of systematic error are considered, with the conclusion that these could affect the estimate of ,m by a few tens of per cent. [source] Relationship between obesity, adipocytokines, and blood pressure: Possible common genetic and environmental factorsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2009Ia Pantsulaia Adipokines may link adipose tissue to the inflammatory, metabolic, and immune dysregulation. The variation of adipokine levels within individuals, intercorrelations, and relationships to well-established measures of adiposity are incompletely defined. The main goal of the present study was quantitative evaluation of the genetic interrelationships between obesity and adipokines in normal human population. The study sample comprised 272 families of various sizes, including 530 men and 531 women aged 18,80 years, randomly recruited in rural population living in Russia. Various fatness and fat distribution measures (OB), blood pressure (BP), and plasma levels of several adipokines (AC), such as adiponectin, leptin, resistin, and IGFBP-1, have been measured. The likelihood ratio tests clearly revealed that genetic effect for all studied phenotypes was highly significant (P < 0.001) and accounted for 45.9% ± 8.1%, 33.7% ± 7.9%, 35.7% ± 9.8% of variation for AC, OB, and BP, respectively. The pairwise bivariate analyses showed that strong phenotypic correlation between the obesity (OB) and adipocytokines (AC) was caused by both common genetic and environmental factors (rG = 0.597 ± 0.116, rE = 0.671 ± 0.051). The phenotypic correlation between BP and OB is explained by shared genetic factors only (rG = 0.532 ± 0.109), whereas the phenotypic correlation between BP and AC has only common environment basis (rE = ,0.212 ± 0.081) and was mostly due to the correlation observed in females. Our results suggest that genetic factors play a significant role in regulation of variation of the examined traits. The variation of OB traits is almost fully due to genes influencing variation of AC, whereas the correlation between BP and AC is only marginally significant and caused only by shared environment. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc. [source] Photoreflectance investigations of energy level structure of InAs quantum dashes embedded in InGaAs/InGaAlAs quantum well grown on InP substratePHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2006W. Rudno-Rudzi Abstract Photoreflectance (PR) and photoluminescence measurements have been performed on molecular beam epitaxy grown InAs quantum dashes (QDash) of various sizes, embedded in In0.53Ga0.47As/In0.53Ga0.23Al0.24As quantum well (QW), grown on InP substrate. PR response from all relevant parts of the structure, i.e InAs/In0.53Ga0.47As QDashes, InAs/In0.53Ga0.47As/In0.53Ga0.23Al0.24As QW, and In0.53Ga0.23Al0.24As barriers, has been obtained. The lowest energy transition related to the ground state transition in QDashes shifts towards red with the increase in QDash sizes (amount of deposited InAs material) reaching wavelengths longer than for structures without the intermediate QW. The experimental data on the energies of optical transitions combined with the numerical calculation within the effective mass approximation has allowed determining the energy level structure of the entire system, including the values of conduction band offset between InGaAs and InGaAlAs layers. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Characteristics of amplified spontaneous emission of high indium content InGaN/GaN quantum wells with various silicon doping conditionsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003Yung-Chen Cheng Abstract We compared the temperature dependent spectral variations of the amplified spontaneous emission (ASE) between InGaN/GaN quantum well samples of no doping, well doping, and barrier doping of silicon. The comparisons were particularly made between two series of samples with a low and a high indium content. The results show that a multi-peak ASE spectral feature and a low energy stimulated emission peak, existing at the photoluminescence shoulder, could be observed only in the high-indium-content, barrier-doped sample. Such results are supposed to originate from the formation of quantum dots of various sizes, concentrations, and shapes under the condition of barrier doping in the sample. (© 2003 WILEY-VCH Verlag GmbH & Co. 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