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Compositional Differences (compositional + difference)
Selected AbstractsIncreasing representation of localized dung beetles across a chronosequence of regenerating vegetation and natural dune forest in South AfricaGLOBAL ECOLOGY, Issue 3 2002Adrian L. V. Davis Abstract Aim Species assemblages with high proportions of localized taxa occur in regional islands with a history of strong eco-climatic separation from adjacent systems. Current disturbance in such islands of relictualism or endemism disrupts the distinctive local character in favour of regionally distributed taxa with a wider range of tolerances. However, rehabilitation of the system should restore the localized biota. Thus, we used biogeographical composition to assess progress towards restoration of the dung beetle fauna associated with such an island of endemism following dredge-mining. Location The study was conducted in natural coastal dune forest and a 23-year chronosequence of regenerating dune vegetation in the Maputaland centre of endemism, KwaZulu-Natal, South Africa. Methods Dung beetles were trapped in eight stands of regenerating vegetation of different ages (< 1 year to ~21 years) and in four stands of natural dune forest with differing ecological characteristics defined by measurements of vegetative physiognomy and microclimate. Species groups defined from multivariate analysis of biogeographical distribution patterns and vegetation associations were used to demonstrate quantitative compositional changes in the dung beetle assemblages across the chronosequence to natural forest. Results Three biogeographical groups were defined. One group comprised species widespread in southern Africa or both southern and east Africa. The other two groups were endemic, one to the east coast and the other to Maputaland. There was a general trend from dominance by regionally distributed dung beetle taxa to dominance by locally distributed taxa across the chronosequence of regenerating vegetation from grassland, to open Acacia karroo thicket, to dense A. karroo- dominated woodland. However, this trend was linked closely to the relative physiognomic and microclimatic similarity between the regenerating vegetation and natural forest. Thus, proportions of locally distributed taxa were lower in older chronosequence woodland (~18,~21 years) with its low canopy cover and open understorey than in dense early chronosequence woodland (~9,~12 years), which is physiognomically and microclimatically closer to species-diverse natural forest with its dense canopy and understorey. Overall, the present dung beetle community comprises five species groups. Single widespread (21 spp.) and endemic groups (14 spp.) showed similar patterns of association with early chronosequence grassland and open thicket stands. A single widespread (3 spp.) and two endemic shade-associated groups (3 and 11 spp.) showed differing patterns of association centred, respectively, in late chronosequence woodland, natural forest, or all shaded stands. Main conclusions At 23 years, vegetative regeneration is still at an early stage, but abundant activity of most, although not all species recorded in natural forest, is recovered with the closure of the woodland canopy at ~9 years. Compositional differences with respect to natural forest vary closely with vegetative physiognomy and its effect on the microclimate. Therefore, full compositional recovery is dependent on the re-establishment of natural forest physiognomy and microclimate. [source] Familial adenomatous polyposis patients have high levels of arachidonic acid and docosahexaenoic acid and low levels of linoleic acid and ,-linolenic acid in serum phospholipidsINTERNATIONAL JOURNAL OF CANCER, Issue 3 2007Kari Almendingen Abstract Familial adenomatous polyposis (FAP) provides a model of APC inactivation as an early genetic event for the ,85% of colorectal cancers that develop from polyps. Abnormal fatty acid composition of tissues and serum phospholipids has been linked to cancer risk. Our aim was to describe the composition of fatty acids in serum phospholipids in 38 colectomized FAP patients as compared to 160 healthy subjects. Mean fatty acid intakes were similar between the groups. Colectomy was done on average 16 years prior to inclusion, and 18% were diagnosed with colorectal cancer at colectomy. The levels (weight %) of linoleic and ,-linolenic acid were higher among the reference subjects (difference: 3.96, 95% confidence interval (CI) = 2.87, 5.04, and difference: 0.06, 95% CI = 0.04, 0.08, respectively), and the levels of arachidonic and docosahexaenoic acid were lower (difference: ,3.70, 95% CI = ,4.35, ,3.06, and difference: ,5.26, 95% CI = ,6.25, ,4.28, respectively) as compared to the FAP patients (all p , 0.0001). The abnormal fatty acid composition was not related to time since colectomy, intestinal reconstruction or history of colorectal cancer for any of the fatty acids assessed. Compositional differences in the fatty acid profile of serum phospholipids have not been described before in FAP patients. Further studies are needed to confirm these findings and assess clinical significances of a possible distorted fatty acid metabolism, including a potentially different dietary need of essential fatty acids. The relevance of these findings for APC induced cancers remains unclear. © 2006 Wiley-Liss, Inc. [source] Direct-temperature mass spectrometric detection of volatile terpenoids and natural terpenoid polymersin fresh and artificially aged resinsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 6 2003Dominique Scalarone Abstract Electron impact (EI) ionization and ammonia chemical ionization (NH3/CI) direct-temperature mass spectrometry (DTMS) was used to characterize five natural terpenoid resins: dammar, mastic, colophony, Manila copal and sandarac. Compositional differences were highlighted by the identification of low molecular mass compounds, ranging from di- to triterpenoids, and polymeric components, based on polycadinene and polycommunic acid. Photo-ageing processes occurring under accelerated indoor and outdoor exposure conditions were also investigated. NH3/CI and tetramethylammonium hydroxide EI were applied to increase the sensitivity towards highly oxidized molecules. Oxidation and cross-linking reactions were found to affect mostly triterpenoid resins and diterpenoid abietane and pimarane molecules. Oxidation proceeds through a radical mechanism, generally starting from conjugated double bonds. Oxygen atoms are incorporated in the terpenoid structures in the form of alcohols, ketones and carboxylic acids. Oxidized cadinene oligomers released by pyrolytic degradation of the polycadinene fraction of dammar were detected even in unaged samples. Evidence is given indicating the occurrence of cleavages in the cross-linked polycommunic structure of aged sandarac and Manila copal. Bond scissions produce oligomeric fragments based on the communic acid structure and sufficiently volatile to be desorbed at low temperature in DTMS measurements. Copyright © 2003 John Wiley & Sons, Ltd. [source] Lunar regolith breccia Dhofar 287B: A record of lunar volcanismMETEORITICS & PLANETARY SCIENCE, Issue 4 2003S. I. Demidova The present study is directed mainly at the breccia portion of this meteorite. This breccia consists of a variety of lithic clasts and mineral fragments set in a fine-grained matrix and minor impact melt. The majority of clasts and minerals appear to have been mainly derived from the low-Ti basalt suite, similar to that of Dho 287A. Very low-Ti (VLT) basalts are a minor lithology of the breccia. These are significantly lower in Mg# and slightly higher in Ti compared to Luna 24 and Apollo 17 VLT basalts. Picritic glasses constitute another minor component of the breccia and are compositionally similar to Apollo 15 green glasses. Dho 287B also contains abundant fragments of Mg-rich pyroxene and anorthite-rich plagioclase grains that are absent in the lithic clasts. Such fragments appear to have been derived from a coarse-grained, Mg#-rich, Na-poor lithology. A KREEP component is apparent in chemistry, but no highlands lithologies were identified. The Dho 287 basaltic lithologies cannot be explained by near-surface fractionation of a single parental magma. Instead, magma compositions are represented by a picritic glass; a low-Ti, Na-poor glass; and a low-Ti, Na-enriched source (similar to the Dho 287A parental melt). Compositional differences among parent melts could reflect inhomogeneity of the lunar mantle. Alternatively, the low-Ti, Na-poor, and Dho 287A parent melts could be of hybrid compositions, resulting from assimilation of KREEP by picritic magma. Thus, the Dho 287B breccia contains lithologies from multiple magmatic eruptions, which differed in composition, formational conditions, and cooling histories. Based on this study, the Dho 287 is inferred to have been ejected from a region located distal to highlands terrains, possibly from the western limb of the lunar nearside, dominated by mare basalts and KREEP-rich lithologies. [source] Composition of organic matter in a subtropical Acrisol as influenced by land use, cropping and N fertilization, assessed by CPMAS 13C NMR spectroscopyEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2005J. Dieckow Summary We know much about the influence of management on stocks of organic matter in subtropical soils, yet little about the influence on the chemical composition. We therefore studied by CPMAS 13C NMR spectroscopy the composition of the above-ground plant tissue, of the organic matter of the whole soil and of silt- and clay-size fractions of the topsoil and subsoil of a subtropical Acrisol under grass and arable crops. Soil samples were collected from three no-till cropping systems (bare soil; oats,maize; pigeon pea + maize), each receiving 0 and 180 kg N ha,1 year,1, in a long-term field experiment. Soil under the original native grass was also sampled. The kind of arable crops and grass affected the composition of the particulate organic matter. There were no differences in the composition of the organic matter in silt- and clay-size fractions, or of the whole soil, among the arable systems. Changes were observed between land use: the soil of the grassland had larger alkyl and smaller aromatic C contents than did the arable soil. The small size fractions contain microbial products, and we think that the compositional difference in silt- and clay-size fractions between grassland and the arable land was induced by changes in the soil's microbial community and therefore in the quality of its biochemical products. The application of N did not affect the composition of the above-ground plant tissue nor of the particulate organic matter and silt-size fractions, but it did increase the alkyl C content in the clay-size fraction. In the subsoil, the silt-size fraction of all treatments contained large contents of aromatic C. Microscopic investigation confirmed that this derived from particles of charred material. The composition of organic matter in this soil is affected by land use, but not by variations in the arable crops grown. [source] Effect of N-fertilization, plant genotype and environmental conditions on nifH gene pools in roots of riceENVIRONMENTAL MICROBIOLOGY, Issue 10 2003Zhiyuan Tan Summary Terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR-amplified nitrogenase gene (nifH) fragments is a rapid technique for profiling of diazotrophic microbial communities without the necessity of cultures for study. Here, we examined the impact of N-fertilization, plant genotype and environmental conditions on diazotrophic microbial populations in association with roots of rice (Oryza species) by T-RFLP community profiling and found marked effects on the composition of the microbial community. We found a rapid change of the diazotrophic population structure within 15 days after application of nitrogen fertilizer and a strong effect of environmental conditions and plant genotype. Control experiments revealed that phylogenetically distantly related nifH genes were proportionately amplified, and that signal strength reflected the relative abundance of nifH genes in the sample within a 10-fold range of template concentrations. These results clearly demonstrated that our T-RFLP method was suitable to reflect compositional differences in the diazotrophic community in a semiquantitative manner and that the diazotrophic rhizosphere communities of rice are not static but presumably rather highly dynamic. [source] Metabolic fingerprinting allows discrimination between Ulmus pumila and U. minor, and between U. minor clones of different susceptibility to Dutch elm diseaseFOREST PATHOLOGY, Issue 4 2008J. A. Martin Summary Experiments were conducted to test whether Fourier transform-infrared (FT-IR) spectroscopy, coupled with chemometric methods, can distinguish healthy xylem tissues collected from elms known to differ significantly in their susceptibility to Ophiostoma novo-ulmi Brasier. Twig samples from resistant Ulmus pumila L., susceptible U. minor Mill. and resistant U. minor clones were harvested on 1 May, 15 May, 1 June, 1 July and 1 September 2004, and subjected to FT-IR analysis. The application of principal component analysis to the spectral data, followed by discriminant function analysis, discriminated between the three groups of samples in all harvesting dates. The examination of the DF-loading plots allowed the identification of key regions within the spectra for the separation between clusters. The chemical assignments of these key regions allowed the following interpretations to be made: (i) U. pumila tissues contained enhanced levels of starch, cellulose and lignin with respect to U. minor tissues and (ii) resistant U. minor tissues contained enhanced levels of starch, cellulose and pectic polysaccharides with respect to susceptible U. minor tissues. The possible roles of the compositional differences in disease resistance, as well as the potential use of FT-IR spectroscopy and chemometrics as a tool for screening resistant elms are discussed. [source] Invertebrate communities associated with a native (Vallisneria americana) and an alien (Trapa natans) macrophyte in a large riverFRESHWATER BIOLOGY, Issue 11 2003David L. Strayer Summary 1. We used a corer and a Downing box sampler to sample macroinvertebrates living on and beneath the introduced Trapa natans and the native Vallisneria americana in the freshwater tidal Hudson River, New York. 2. Densities of macroinvertebrates were higher in Trapa than in Vallisneria, and higher in the interior of plant beds than at their edges. These effects were largely a result of high plant biomass in Trapa beds and in bed interiors (the plants have similar surface area per unit mass). 3. The composition of both epiphytic and benthic macroinvertebrates differed distinctly between Trapa and Vallisneria, and also seasonally. 4. These compositional differences were not easily interpretable as rising from possible differences in oxygen concentrations, fish predation, or water circulation in the two macrophytes. 5. Sida crystallina (Cladocera) collected from Trapa contained more haemoglobin than those collected from Vallisneria. 6. The replacement of Vallisneria by Trapa in the Hudson probably increased system-wide biodiversity and food for fish, although macroinvertebrates in Trapa beds may not be readily available to fish because of low oxygen concentration there. [source] Quality Attributes and Microbial Storage Stability of Caviar from Cultivated White Sturgeon (Acipenser transmontanus)JOURNAL OF FOOD SCIENCE, Issue 1 2010Joong-Han Shin ABSTRACT:, Caviar was prepared from white sturgeon (Acipenser transmontanus) roe by adjusting the water phase salt (WPS) to 4.0% to 6.3% by adding food grade NaCl. Fish were obtained from 2 different farms from the Inland Northwest (N,= 5). Salt was absorbed at a different rate and to a different extent by roe from different fish. The lipid content in the fish roe varied from 10.2% to 14.4% (w/w), with palmitic acid and oleic acid being the most abundant saturated and monounsaturated fatty acids present, respectively. The caviar contained high levels of polyunsaturated fatty acids (PUFA) (35% to 37%) with docosahexanoic acid being the most abundant ,-3 long chain fatty acid. There were no significant differences in microbial storage stability for caviars from different fish stored at 3 °C. However, for caviar stored at 7 °C, there was less growth of,Listeria monocytogenes,(using a cocktail of ATCC 19114, 7644, 19113 strains) in 2 samples (2B46 and 0F05) until day 20. In 2 other samples (453F and 2519), which had lower initial microbial loads, less overall microbial growth was observed, indicating that culture and harvest practices result in compositional differences between fish, which may impact both product composition and storage stability. [source] MAIN FACTORS CONTROLLING THE COMPOSITIONAL VARIABILITY OF SEEPAGE OILS FROM TRUJILLO STATE, WESTERN VENEZUELAJOURNAL OF PETROLEUM GEOLOGY, Issue 3 2010F. Galarraga The organic geochemistry of eighteen samples of seepage oils from Trujillo State, Western Venezuela, was investigated. These oils are probably derived from the predominantly marine Cretaceous La Luna Formation which is near peak maturity for oil generation. A range of biomarkers (n-alkanes, acyclic isoprenoids, phenanthrene and alkyl-phenanthrenes, as well as dibenzothiophene and alkyl-dibenzothiophenes) were analysed by gas chromatography - mass spectrometry (GC-MS). The seepage oils have been modified as a result of water washing and biodegradation. A first group of samples were slightly biodegraded with the partial loss of n- and iso-alkanes. Other samples fall into two groups: those that are moderately degraded, with partial depletion of acyclic isoprenoids; and those that are severely altered, as indicated by the partial or total absence of hopanes. One objective of this work was to evaluate the factors influencing the compositional differences of the three samples sets. In-situ measurements, together with the interpretation of the geochemical data, suggest that diverse factors were responsible for these variations. These included different degrees of alteration due to biodegradation and water washing, as well as differences in flow rate towards the surface. [source] Microstructure in Silicon Nitride Containing ,-Phase Seeding: III, Grain Growth and CoalescenceJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2001Horng-Hwa Lu The mechanical properties of Si3N4 materials depend mainly on the microstructure, which originates during the densification process. The microscopic evidence indicates that ,-Si3N4 seeds incorporated in the starting powders play an important role in microstructural development, especially in the heterogeneous grain growth of ,-Si3N4 grains during sintering. The growth of ,-grains is initiated from the ,-seeds, resulting in a core/shell microstructure. The presence of Moiré fringes and dislocations is attributed to misfit strain and compositional differences between the core and the shell. Coalescence can occur at the final stage of sintering. [source] Geochemistry and origin of metal, olivine clasts, and matrix in the Dong Ujimqin Qi mesosideriteMETEORITICS & PLANETARY SCIENCE, Issue 3 2008Ping Kong According to silicate textures and metal composition, this meteorite is classified as a member of subgroup IB. Instrumental neutron activation analyses (INAA) of metals show that the matrix metal has lower concentrations of Os, Ir, Re, and Pt, but higher concentrations of Ni and Au than the 7.5 cm metal nodule present in the meteorite. We attribute these compositional differences to fractional crystallization of molten metal. Studies of olivine clasts show that FeO contents are uniform in individual olivine crystals but are variable for different olivine clasts. Although concentrations of rare earth elements (REEs) change within olivine clasts, they all exhibit a vee-shaped pattern relative to CI chondrites. The relatively high concentrations of REEs in olivine and the shape of REE patterns require a liquid high in REEs and especially in light REEs. As such a liquid was absent from the region where basaltic and gabbroic clasts formed, mesosiderite olivine must have formed in a part of the differentiated asteroid that is different from the location where other mesosiderite silicate clasts formed. [source] A petrologic and trace element study of Dar al Gani 476 and Dar al Gani 489: Twin meteorites with affinities to basaltic and lherzolitic shergottitesMETEORITICS & PLANETARY SCIENCE, Issue 2 2001M. WADHWA Having resided in a hot desert environment for an extended time, DaG 476 and DaG 489 were subjected to terrestrial weathering that significantly altered their chemical composition. In particular, analyses of some of the silicates show light rare earth element (LREE)-enrichment resulting from terrestrial alteration. In situ measurement of trace element abundances in minerals allows us to identify areas unaffected by this contamination and, thereby, to infer the petrogenesis of these meteorites. No significant compositional differences between DaG 476 and DaG 489 were found, supporting the hypothesis that they belong to the same fall. These meteorites have characteristics in common with both basaltic and lherzolitic shergottites, possibly suggesting spatial and petrogenetic associations of these two types of lithologies on Mars. However, the compositions of Fe-Ti oxides and the size of Eu anomalies in the earliest-formed pyroxenes indicate that the two Saharan meteorites probably experienced more reducing crystallization conditions than other shergottites (with the exception of Queen Alexandra Range (QUE) 94201). As is the case for other shergottites, trace element microdistributions in minerals of the DaG martian meteorites indicate that closed-system crystal fractionation from a LREE-depleted parent magma dominated their crystallization history. Furthermore, rare earth element abundances in the orthopyroxene megacrysts are consistent with their origin as xenocrysts rather than phenocrysts. [source] Experimental plant invasion reduces arthropod abundance and richness across multiple trophic levelsOIKOS, Issue 10 2010M. Carolina M. Simao Plant invasions are known to have negative impacts on native plant communities, yet their influence on higher trophic levels has not been well documented. Past studies investigating the effects of invasive plants on herbivores and carnivores have been largely observational in nature and thus lack the ability to tease apart whether differences are a cause or consequence of the invasion. In addition, understanding how plant traits and plant species compositions change in invaded habitats may increase our ability to predict when and where invasive plants will have effects that cascade to animals. To assess effects on arthropods, we experimentally introduced a non-native plant (Microstegium vimineum, Japanese stiltgrass) in a community re-assembly experiment. We also investigated possible mechanisms through which the invader could affect associated arthropods, including changes in native plant species richness, above-ground plant biomass, light availability and vegetation height. In experimentally invaded plots, arthropod abundance was reduced by 39%, and species richness declined by 19%. Carnivores experienced greater reductions in abundance than herbivores (61% vs 31% reduction). Arthropod composition significantly diverged between experimentally invaded and control plots, and particular species belonging to the abundant families Aphididae (aphids), Formicidae (ants) and Phalacridae (shining flower beetles) contributed the most to compositional differences. Among the mechanisms we investigated, only the reduction in native plant species richness caused by invasion was strongly correlated with total arthropod abundance and richness. In sum, our results demonstrate negative impacts of M. vimineum invasion on higher trophic levels and suggest that these effects occur, in part, indirectly through invader-mediated reductions in the richness of the native plant community. The particularly strong response of carnivores suggests that plant invasion could reduce top,down control of herbivorous species for native plants. [source] Structure and composition of the postsynaptic density during developmentTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 20 2010Matthew T. Swulius Abstract In this study, we used electron tomography as well as immunogold labeling to analyze the morphology and distribution of proteins within postsynaptic densities (PSDs) isolated from rats before birth (embryonic day 19) and at postnatal days 2, 21, and 60. Our data provide direct evidence of distinct morphological and compositional differences in PSDs throughout development. Not all PSD components are present at the early stages of development, with a near lack of the scaffolding molecule PSD-95 at E19 and P2. The presence of NR1 and NR2b suggests that PSD-95 is not directly required for clustering of N-methyl-D-aspartic acid (NMDA) receptors in PSDs early in development. ,-Actinin is abundant by E19, suggesting that it is a core structural component of the PSD. Both , and , isoforms of Ca2+/calmodulin-dependent protein kinase II (CaMKII) are present early on but then rise in labeling density by approximately fourfold by P21. Among all the molecules studied, only calmodulin (CaM) was found in higher abundance early in PSD development and then fell in amount over time. Spatial analysis of the immunogold label shows a nonrandom distribution for all the proteins studied, lending support to the idea that the PSD is systematically assembled in an organized fashion. Morphological data from electron tomography shows that the PSD undergoes major structural changes throughout development. J. Comp. Neurol. 518:4243,4260, 2010. © 2010 Wiley-Liss, Inc. [source] Thermogravimetric evaluation of perennial ryegrass (Lolium perenne) for the prediction of in vitro dry matter digestibilityANNALS OF APPLIED BIOLOGY, Issue 3 2008H.S.S. Sharma Abstract Thermogravimetry (TG) can be used for assessing the compositional differences in grasses that relate to dry matter digestibility (DMD) determined by pepsin,cellulase assay. This investigation developed regression models for predicting DMD of herbage grass during one growing season using TG results. The calibration samples were obtained from a field trial of eight cultivars and two breeding lines. The harvested materials from five cuts were analysed by TG to identify differences in the combustion patterns within the range of 30,600°C. The discrete results including weight loss, peak height, area, temperature, widths and residue of three decomposition peaks were regressed against the measured DMD values of the calibration samples. Similarly, continuous weight loss results of the same samples were also utilised to generate DMD models. The r2 for validation of the discrete and the best continuous models were 0.90 and 0.95, respectively, and the two calibrations were validated using independent samples from 24 plots from a trial carried out in 2004. The standard error for prediction of the 24 samples by the discrete model (4.14%) was higher than that by the continuous model (2.98%). This study has shown that DMD of grass could be predicted from the TG results. The benefit of thermal analysis is the ability to detect and show changes in composition of cell wall fractions of grasses during different cuts in a year. [source] Land-use legacies in a central Appalachian forest: differential response of trees and herbs to historic agricultural practicesAPPLIED VEGETATION SCIENCE, Issue 2 2010James M. Dyer Abstract Question: Are contemporary herb and tree patterns explained by historic land use practices? If so, are observed vegetation patterns associated with life-history characteristics, soil properties, or other environmental variables? Location: Southeastern Ohio, USA. Methods: Using archival records, currently forested sites were identified with distinct land use histories: cultivated, pasture (but not plowed), and reference sites which appear to have never been cleared. Trees were recorded by size and species on twenty 20 m × 20 m plots; percent cover was estimated for each herb species in nested 10 m × 10 m plots. Environmental characteristics were noted, and soil samples analysed for nutrient availability and organic matter. Nonmetric multidimensional scaling ordination was performed separately on both tree and herb datasets to graphically characterize community composition among plots. Life-history traits were investigated to explain observed compositional differences. Results: Vegetation patterns were explained by current environmental gradients, especially by land-use history. Cultivated and pasture sites had similar tree composition, distinct from reference sites. Herb composition of pasture and reference sites was similar and distinct from cultivated sites, suggesting the ,tenacity' of some forest herbs on formerly cleared sites. Tilling removes rhizomatous species, and disfavors species with unassisted dispersal. These life-history traits were underrepresented on cultivated sites, although ant-dispersed species were not. Conclusions: Historic land-use practices accounted for as much variation in species composition as environmental gradients. Furthermore, trees and herbs responded differently to past land-use practices. Life-history traits of individual species interact with the nature of disturbance to influence community composition. [source] ANALYSIS OF FIRST MILLENNIUM bc GLASS VESSELS AND BEADS FROM THE PICHVNARI NECROPOLIS, GEORGIA*ARCHAEOMETRY, Issue 6 2009A. J. SHORTLAND The Pichvnari necropolis on the Black Sea coast of Georgia lies in an area known in the late first millennium as ,Colchis', on part of the trade route leading to the Orient. The burials of the necropolis date to the late fifth century bc and frequently contain grave goods, including extremely well-preserved polychrome glass beads and core-formed vessels. This paper presents a study of these vessels both stylistically and archaeologically and using SEM,WDS and LA,ICPMS. It reveals that the vessels have compositional differences that may point to multiple manufacturing sites. One of the vessels appears stylistically unique and may exhibit one of the earliest uses of manganese as a decolorizer. Major and minor element data for the vessels suggest that they may belong to the same ,Levantine' group as many Roman glass objects, suggesting that a source of sand on the coast of the Levant could have been used in their production. The beads clearly show glass with both natron- and plant ash-based flux with distinct rare earth compositions, showing multiple sites of production, some of which were probably either in the Middle East or the Indian subcontinent. [source] Work Pressure in Europe 1996,2001: Trends and DeterminantsBRITISH JOURNAL OF INDUSTRIAL RELATIONS, Issue 3 2005Duncan Gallie Diverse theories have predicted a trend towards growing work pressure in advanced capitalist societies, while pointing to quite distinct causal factors. This paper seeks to assess these arguments using data from two surveys of employees in European Union member-states carried out in 1996 and in 2001. It finds there is no evidence of a trend towards higher work pressure over this period. There is, however, support for some of the main arguments about the types of factors that affect work pressure: for instance, skill, job control, new technology and current job security are clearly important. But the trends in job control and job security have not been those predicted, while changes in another major determinant , the length of working hours , have tended to reduce work pressure. There are substantial and relatively stable differences in work pressure between countries, but to a considerable extent, these reflect compositional differences with respect to the main determinants of work pressure. [source] Aspects of Infant Food FormulationCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 4 2007D.K. Thompkinson ABSTRACT:, Milk is a biological fluid of exceptional complexity. It contains the nutrients for the growth and development of the newborn. The compositional structure of milk is, however, dependent on the species and tailored to sustain growth and development of its own offspring. Human milk contains specific proteins, lipids, and other components designed to be easily digestible and which have important roles to play in child development. Human infants should ideally be nursed on mother's milk, which constitutes nature's best food. However, in the event of lactation failure, insufficient milk secretion, and where mothers are suffering from transmittable diseases, human milk substitutes serve as savers of precious life during vulnerable stages of infancy. Bovine milk as such or with certain modifications has been widely used for infant feeding. There has been an ever-increasing reliance on formula feeding practices both in developed and developing countries. Bovine milk based dried formulations have become a prominent feature of infantile dietetics. Emphasis has been laid on the manufacture of formulations having compositional and biochemical characteristics similar to human milk. The technological advancement for the production of infant formula has come a long way in the manufacture of a variety of infant formulae for the dietary management of infants. This is a comprehensive review providing insight on the detailed compositional differences of various nutrients present in human milk as compared to bovine milk, their makeup, significance, and recommended levels of intake that are best suited for the growth and development of infants fed on modified/prepared infant formulations. [source] | |||||||||||||||||||