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Same Process (same + process)
Selected AbstractsBelief-Independent Processes and the Generality Problem for ReliabilismDIALECTICA, Issue 1 2005Mark McEvoy The Generality Problem for process reliabilism is to outline a procedure for determining when two beliefs are produced by the same process, in such a way as to avoid, on the one hand, individuating process types so narrowly that each type is instantiated only once, or, on the other hand, individuating them so broadly that beliefs that have different epistemic statuses are subsumed under the same process type. In this paper, I offer a solution to the problem which takes belief-independent processes to be functions that take as inputs information about distal states of affairs, and produce beliefs as outputs. Processes are individuated narrowly, so as to avoid the latter aspect of the Generality problem, but, by holding process tokens to be of the same type when they take perceptually equivalent scenes as inputs, and produce beliefs of the same kind as outputs, the former aspect of the problem is avoided too. Having argued that this method of typing process tokens solves the Generality Problem, I then argue that my solution does not fall prey to objections that have been, or might be, raised for similar proposals. [source] Ultrastructural features of the process of wound healing after tail and limb amputation in lizardACTA ZOOLOGICA, Issue 3 2010L. Alibardi Abstract Alibardi, L. 2010. Ultrastructural features of the process of wound healing after tail and limb amputation in lizard.,Acta Zoologica (Stockholm) 91: 306,318 Wound healing and re-epitelization after amputation of tail and limb in lizard have been studied by electron microscopy to understand the cytological base of immunity to infection in this species. After 2 days post-amputation in both limb and tail stumps, numerous granulocytes are accumulated over the stump, and participate to the formation of the scab. Bacteria remain confined to the scab or are engulfed by leukocytes and migrating keratinocytes located underneath the scab. Bacteria are degraded within lysosomes present in these cells and are not observed among mesenchymal cells or in blood vessels of the regenerative blastema. Granulocytes, migrating keratinocytes, and later macrophages form an effective barrier responsible for limiting microbe penetration. The innate immunity in lizard is very effective in natural (dirty) condition and impedes the spreading of infection to inner tissues. While the complete re-epitelization of the tail stump underneath the scab requires 4,7 days, the same process in the limb requires 8,18 or more days post-amputation, depending from the level of amputation and the persistence of a protruding humerus or femurs on the stump surface. This delay produces the permanence of inflammatory cells such as granulocytes and macrophages in the limb stump for a much longer period than in the tail stump, a process that stimulates scarring. [source] Fabrication of enclosed SU-8 tips for electrospray ionization-mass spectrometryELECTROPHORESIS, Issue 24 2005Santeri Tuomikoski Dr. Abstract We describe a novel electrospray tip design for MS which is fabricated completely out of SU-8 photoepoxy. A three-layer SU-8 fabrication process provides fully enclosed channels and tips. The tip shape and alignment of all SU-8 layers is done lithographically and is therefore very accurate. Fabrication process enables easy integration of additional fluidic functions on the same chip. Separation channels can be made with exactly the same process. Fluidic inlets are made in SU-8 during the fabrication process and no drilling or other postprocessing is needed. Channels have been fabricated and tested in the size range of 10,,m×10,,m,50,,m×200,,m. Mass spectrometric performance of the tips has been demonstrated with both pressure-driven flow and EOF. SU-8 microtips have been shown to produce stable electrospray with EOF in a timescale of tens of minutes. With pressure driven flow stable spray is maintained for hours. Taylor cone was shown to be small in volume and well defined even with the largest channel cross section. The spray was also shown to be well directed with our tip design. [source] An evaluation of continuous electrodeionization as an in-line process for plating rinsewater recoveryENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2001M. J. Semmens The objective of this project was to investigate the ability of continuous electrodeionization (CEDI) to be used in a copper electroplating line to recover copper sulfate and purified water from rinsewaters for reuse within the same process. Typically, these acidic rinsewaters contain approximately 10 to 50 mg/L of copper as copper sulfate. This range of copper is much higher than any used in previous applications of CEDI technology. Three bench-scale configurations of CEDI modules were evaluated under varying flow and voltage conditions to test the performance of the process in treating the rinsewater. The influence of different ion exchange packings on CEDI performance was examined to determine which module design worked best for this separation process. The bench-scale test results suggest that CEDI is a potentially viable technology for copper sulfate recovery from waste rinsewaters generated by a copper electroplating line. A single stage CEDI process was able to produce a pure water product containing non-detectable concentrations of copper, and an acidic copper sulfate concentrate with a copper concentration as high as 4,000 mg/L. [source] PRECLINICAL STUDY: Effect of concurrent saccharin intake on ethanol consumption by high-alcohol-drinking (UChB) ratsADDICTION BIOLOGY, Issue 3 2009Lutske Tampier ABSTRACT This study examined the effect of concurrent presentation of a highly palatable saccharin solution on ethanol consumption during the acquisition or maintenance of ethanol drinking by high-alcohol-drinking (UChB) rats. Rats were exposed to ethanol (10% v/v) and water under a home cage, two-bottle, free-choice regimen with unlimited access for 24 hours/day. After 7 days (acquisition) of ethanol exposure, a third bottle containing saccharin (0.2% w/v) was concomitantly offered for an additional seven consecutive days, and the same process was repeated after 3 months (maintenance) of ethanol exposure. We found that concurrent saccharin intake significantly reduced ethanol intake by UChB rats after 7 days of ethanol exposure indicating that preference for sweet taste tends to override the preference for ethanol. However, the concurrent saccharin presentation to rats after 3 months of stable ethanol consumption did not reduce ethanol intake, whereas their saccharin consumption reached polydipsic-like values. These results support the notion that in UChB rats, a time-dependent sensitization to the rewarding effects of ethanol is developed that may account for the increases in ethanol volition seen following chronic ethanol intake. [source] Modularity of the rodent mandible: Integrating bones, muscles, and teethEVOLUTION AND DEVELOPMENT, Issue 6 2008Miriam Leah Zelditch Summary Several models explain how a complex integrated system like the rodent mandible can arise from multiple developmental modules. The models propose various integrating mechanisms, including epigenetic effects of muscles on bones. We test five for their ability to predict correlations found in the individual (symmetric) and fluctuating asymmetric (FA) components of shape variation. We also use exploratory methods to discern patterns unanticipated by any model. Two models fit observed correlation matrices from both components: (1) parts originating in same mesenchymal condensation are integrated, (2) parts developmentally dependent on the same muscle form an integrated complex as do those dependent on teeth. Another fits the correlations observed in FA: each muscle insertion site is an integrated unit. However, no model fits well, and none predicts the complex structure found in the exploratory analyses, best described as a reticulated network. Furthermore, no model predicts the correlation between proximal parts of the condyloid and coronoid, which can exceed the correlations between proximal and distal parts of the same process. Additionally, no model predicts the correlation between molar alveolus and ramus and/or angular process, one of the highest correlations found in the FA component. That correlation contradicts the basic premise of all five developmental models, yet it should be anticipated from the epigenetic effects of mastication, possibly the primary morphogenetic process integrating the jaw coupling forces generated by muscle contraction with those experienced at teeth. [source] An evolutionary fast-track to biocalcificationGEOBIOLOGY, Issue 3 2010D. J. JACKSON The ability to construct mineralized shells, spicules, spines and skeletons is thought to be a key factor that fuelled the expansion of multicellular animal life during the early Cambrian. The genes and molecular mechanisms that control the process of biomineralization in disparate phyla are gradually being revealed, and it is broadly recognized that an insoluble matrix of proteins, carbohydrates and other organic molecules are required for the initiation, regulation and inhibition of crystal growth. Here, we show that Astrosclera willeyana, a living representative of the now largely extinct stromatoporid sponges (a polyphyletic grade of poriferan bauplan), has apparently bypassed the requirement to evolve many of these mineral-regulating matrix proteins by using the degraded remains of bacteria to seed CaCO3 crystal growth. Because stromatoporid sponges formed extensive reefs during the Paelozoic and Mesozoic eras (fulfilling the role that stony corals play in modern coral reefs), and fossil evidence suggests that the same process of bacterial skeleton formation occurred in these stromatoporid ancestors, we infer that some ancient reef ecosystems might have been founded on this microbial,metazoan relationship. [source] Laboratory identification of factor VIII inhibitors in the real world: the experience from AustralasiaHAEMOPHILIA, Issue 4 2010E. J. FAVALORO Summary., The laboratory has a key role in the initial detection of factor inhibitors and an ongoing role in the measurement of inhibitor titres during the course of inhibitor eradication therapy. The most commonly seen factor inhibitors are those directed against factor VIII (FVIII), usually detected either using the original or Nijmegen-modified Bethesda assay. In view of previously demonstrated high variability in laboratory results for inhibitor assays, we have more extensively examined laboratory performance in the identification of FVIII inhibitors. Over the past 3 years, we conducted two questionnaire-based surveys and two wet-challenge surveys utilizing eight samples comprising no FVIII inhibitor (n = 1), or low-titre (n = 2), medium-titre (n = 3) or high-titre (n = 2) FVIII inhibitor. Four samples were tested by 42 laboratories in 2007, and four by 52 laboratories in 2009. High inter-laboratory variation was evident, with CVs around 50% not uncommon, and some 10% of all laboratories (or around 15% of laboratories using Bethesda method) failed to detect low-level inhibitors of around 1 BU mL,1. Laboratories using the Nijmegen method appeared to perform better than those using a standard Bethesda assay, with lower evident assay variation and no false negatives. There was a wide variety of laboratory practice, with no two laboratories using exactly the same process for testing and interpretation of factor inhibitor findings. In conclusion, our study indicates that there is still much need for standardization and improvement in factor inhibitor detection, and we hope that our findings provide a basis for future improvements in this area. [source] Independent component analysis of erroneous and correct responses suggests online response controlHUMAN BRAIN MAPPING, Issue 9 2010Sven Hoffmann Abstract After errors in reaction tasks, a sharp negative wave emerges in the event-related potential (ERP), the error (related) negativity (Ne or ERN). However, also after correct trials, an Ne-like wave is seen, called CRN or Nc, which is much smaller than the Ne. This study tested the hypothesis whether Ne and Nc reflect the same functional process, and whether this process is linked to online response control. For this purpose, independent component analysis (ICA) was utilized with the EEG data of two types of reaction tasks: a flanker task and a mental rotation task. To control for speed-accuracy effects, speed and accuracy instructions were balanced in a between subjects design. For both tasks ICA and dipole analysis revealed one component (Ne-IC) explaining most of the variance for the difference between correct and erroneous trials. The Ne-IC showed virtually the same features as the raw postresponse ERP, being larger for erroneous compared to correct trials and for the flanker than for the rotation task. In addition, it peaked earlier for corrected than for uncorrected errors. The results favor the hypothesis that Ne and Nc reflect the same process, which is modulated by response correctness and type of task. On the basis of the literature and the present results, we assume that this process induces online response control, which is much stronger in error than correct trials and with direct rather than indirect stimulus response mapping. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source] The cycle of instability: stress release and fissure flow as controls on gully head retreatHYDROLOGICAL PROCESSES, Issue 1 2001A. J. C. Collison Abstract Gully head and wall retreat has commonly been attributed to fluvial scour and head collapse as a result of soil saturation, sapping or piping. The empirical evidence to substantiate these conceptual models is sparse, however, and often contradictory. This paper explores the hydrological and mechanical controls on gully head and wall stability by modelling the hydrology, stability and elastic deformation of a marl gully complex in Granada Province, south-east Spain. The hydrological and slope-stability simulations show that saturated conditions can be reached only where preferential fissure flow channels water from tension cracks into the base of the gully head, and that vertical or subvertical heads will be stable unless saturation is achieved. Owing to the high unsaturated strengths of marl measured in this research, failure in unsaturated conditions is possible only where the gully head wall is significantly undercut. Head retreat thus requires the formation of either a tension crack or an undercut hollow. Finite-element stress analysis of eroding slopes reveals a build up of shear stress at the gully head base, and a second stress anomaly just upslope of the head wall. Although tension cracks on gully heads have often been attributed to slope unloading, this research provides strong evidence that the so called ,sapping hollow' commonly found in the gully headwall base is also a function of stress release. Although further research is needed, it seems possible that ,pop out' failures in river channels may be caused by the same process. The hydrological analysis shows that, once a tension crack has developed, throughflow velocity in the gully headwall will increase by an order of magnitude, promoting piping and enlargement of this weakened area. It is, therefore, possible to envisage a cycle of gully expansion in which erosion, channel incision or human action unloads the slope below a gully head, leading to stress patterns that account for the tension crack and a stress-release hollow. The tension crack promotes faster throughflow, encouraging hollow enlargement and piping, which undercut the gully head. The tension crack permits the development of positive pore-water pressures behind the gully head, leading either to failure or contributing to toppling. Finally the debris may be eroded by fluvial action, unloading a new section of slope and completing the cycle of gully head retreat. Copyright © 2001 John Wiley & Sons, Ltd. [source] Pulsed Vapor-Liquid-Solid Growth of Antimony Selenide and Antimony Sulfide NanowiresADVANCED MATERIALS, Issue 31 2009Ren Bin Yang Antimony sulfide and antimony selenide nanowires are prepared in an original pulsed vapor-liquid-solid growth mode. The molecular precursors are not mixed together in the gas phase; therefore the chemical reaction forming the solid only occurs in the gold catalyst. The material is stoichiometric and highly crystalline. Wires consisting of Sb2S3 and Sb2Se3 segments can be obtained with the same process. [source] Peau sèche-rêche et "Hydratation".INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 4 2004Concept de la capture de l'eau organisée comme de la glace Synopsis About sixty years ago Frank and Evans showed, by entropy measurements, that when a "non-polar molecule dissolves in water it modifies the water structure in the direction of greater ,cristallinity', the water builds a microscopic iceberg around it" Now, we propose the "concept of ice-like-water capture": a lowering of organized ice-like water promotes aggregation (loss of solubility) of the filaggrin/keratin1/keratin10 associations through their hydrophobic patches. The capture of ice-like water may be performed by the glucoceramides-rich bilayers in stratum granulosum. Probably, the same process aggregates the proteins of corneocytes envelope as well as corneodesmosomes proteins. According to the "concept of ice-like-water capture", to regulate the keratinization, it is not total water that must be added to the stratum corneum, but ice-like water that must be removed from stratum granulosum. Both petrolatum (lipophilic ingredient) and glycerol (hydrophilic ingredient) would capture the ice-like water, most probably after combination with the lipid bilayers of stratum corneum. Moisturizing cream, when organized in secondary droplets is likely to perform the same action. Measurements by near-infrared reflectance spectroscopy of the skin show that petrolatum; glycerol and/or moisturizing cream enhance the quantity of bulk water (1890,1897 nm band). As the ice-like water is the complement of bulk water, the enhanced bulk water let presume an ice-like water lessening. Some desynchronization (late or forward) of the keratinization/differentiation which confer the somatosensory problems associated with "dry and flaky skin" may be linked to an excess or lack of ice-like. For instance, the winter xerosis, very common by chilling weather, could be explained by an increase of ice-like water driven by the fall of the temperature. Résumé En s'appuyant: 1°-sur d'anciens travaux de thermodynamique montrant, d'une part que les molécules d'eau autour des zones apolaires en solution dans l'eau s'organise selon une structure d'eau-comme-de-la-glace, d'autre part qu'en l'absence de cette eau-comme-de-la-glace les molécules de protéines s'agrègent par leurs zones hydrophobes; 2°-sur des travaux récents utilisant la spectroscopie de l'infrarouge proche; technique qui permet de mesurer la quantité d'eau-en-vrac, forme que prend l'eau-comme-de-la-glace après sa fusion lors de l"établissement de liaisons/interactions hydrophobes; nous proposons le "concept de la capture de l"eau-comme-de-la-glace" selon lequel : 1° la différenciation des kératinocytes, qui se traduit à la fois par l'agrégation des trios filaggrine/K1/K10 (ainsi que notamment la formation de l'enveloppe des cornéocytes et des cornéodesmosomes) est promue par une baisse de la teneur en eau organisée dans le stratum granulosum. La captation de l'eau-comme-de-la-glace pourrait être assurée in situ par la structure lipidique riche en glucocéramides dont l'apparition dans le stratum granulosum est contemporaine du début de la baisse de la teneur en eau; 2° contrairement à la "tradition", la peau sèche-rêche n'est pas améliorée par une augmentation de l'hydratation du stratum corneum mais par la capture d'eau-comme-de-la-glace dans le stratum granulosum. 3° le glycérol, la Vaseline et les crèmes "hydratantes" peuvent concourir à cette capture d'eau-comme-de-la-glace, vraisemblablement après s"être combinés aux bicouches céramidiques du stratum corneum, et ainsi agir depuis ce stratum sur le stratum granulosum. 4°-la baisse hivernale de la température provoque une baisse de la quantité d'eau organisée et confère une aggravation de la peau sèche-rêche. 5°-une désynchronisation de la synthèse ou une modification de la structure et/ou de la composition des bicouches glucocéramidiques du stratum granulosum pourraient être à l'origine de certains types de peau sèche-rêche. [source] Fullerene-Promoted Singlet-Oxygen Photochemical Oxygenations in Glass-Polymer Microstructured ReactorsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2008Tommaso Carofiglio Abstract In this paper we report the fabrication of thiolene-based microstructured reactors (MRs) that have been specifically designed to include solid-supported reagents within the microchannels network. We propose a convenient solution to realize reversible press-fit, leak-proof interconnects that greatly simplify the MR coupling to the external environment such as capillary tubing, sample reservoirs and pumps. The MRs have been used to carry out the oxidation of ,-terpinene and methionine using [60]fullerene, covalently linked to Tentagel® and silica gel matrices, as a singlet oxygen sensitizer. High conversions have been observed for both substrates although, in the case of ,-terpinene, a partial photodegradation of the endo -peroxide product was detected. Interestingly, in the case of methionine, a quantitative conversion to the corresponding sulfoxides was achieved in about 40 seconds, using low-power, white LED illumination. The reaction time is considerably shorter when compared to the batch procedure that requires, for the same process, about one hour illumination and the use of a 300-W tungsten halogen lamp. [source] Social semantics: toward a genuine pluralism in the study of social behaviourJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2008D. S. WILSON Abstract Pluralism is the coexistence of equivalent theoretical frameworks, either because they are historically entrenched or because they achieve separate insights by viewing the same process in different ways. A recent article by West et al. [Journal of Evolutionary Biology (2007) vol. 20, 415,432] attempts to classify the many equivalent frameworks that have been developed to study the evolution of social behaviour. This article addresses shortcomings in the West et al.'s article, especially with respect to multilevel selection, in a common effort to maximize the benefits of pluralism while minimizing the semantic costs. [source] DEHYDRATION CHARACTERISTICS OF PAPAYA (CARICA PUBENSCENS): DETERMINATION OF EQUILIBRIUM MOISTURE CONTENT AND DIFFUSION COEFFICIENTJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2009R. LEMUS-MONDACA ABSTRACT This study determined the drying kinetics behavior of papaya at different temperatures (40, 50, 60, 70 and 80C). Desorption isotherms were determined at 5, 20 and 50C over a relative humidity range of 10,95%. The Guggenheim, Anderson and de Boer models were found to be suitable for description of the sorption data. The samples reached equilibrium moisture of 0.10 ± 0.01 g water/g dry matter. Fick's second law model was used to calculate the effective diffusivity (6.25,24.32 × 10 - 10 m2/s). In addition, experimental data were fitted by means of seven mathematical models. The kinetic parameters and the diffusion coefficient were temperature-dependent and were evaluated by an Arrhenius-type equation. The modified Page model obtained the best-fit quality on experimental data according to statistical tests applied. PRACTICAL APPLICATIONS The main utility of this study is the application of both different empirical models and the diffusional model in tropical fruits' dehydration, which can be considered a basis for a very accurate estimation of drying time and the optimization of the same process. Two newly mathematical models are proposed in this study, through which a good fit on the data of experimental moisture content was achieved. The study of drying of papaya cultivated in Chile engages a great technological interest, because this product is widely used in the development of different products such as candying, canning, juice, syrup and marmalade. In addition, papayas cultivated in Chile, along with other tropical fruits cultivated in Brazil, Colombia and the Caribbean, have become especially important in the exportations of these countries. The major markets for these products include the U.S.A., the European Community and Asia. [source] Optimal design of azeotropic batch distillationAICHE JOURNAL, Issue 3 2006M. C. Mussati Abstract This study explores integrating models with different degrees of detail for optimizing azeotropic batch distillation systems. A detailed dynamic model is used from outside the optimization program both to verify feasibility of the design and to update the parameters needed by the optimization model. The updated parameters are the constant relative volatilities between pseudo-components, used in a binary Fenske,Underwood,Gilliland-type model. The approach was used to optimize the design of a batch process for the recovery of spent isopropyl alcohol, which works cyclically to separate the excess water, satisfying an environmentally acceptable specification, and using cyclohexane as entrainer, which in turn is recovered in the same process and recycled. The approach permitted optimizing the batch sizes, number of separation stages, the reflux ratios of a piecewise constant multilevel reflux policy, the extent of each separation, and the size of the intermediate cuts to be recycled, with affordable computation and problem setup times. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] Two-phase flow electrosynthesis: Comparing N -octyl-2-pyrrolidone,aqueous and acetonitrile,aqueous three-phase boundary reactionsJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 1 2009Stuart M. MacDonald Abstract A microfluidic double channel device is employed to study reactions at flowing liquid,liquid junctions in contact with a boron-doped diamond (BDD) working electrode. The rectangular flow cell is calibrated for both single-phase liquid flow and biphasic liquid,liquid flow for the case of (i) the immiscible N -octyl-2-pyrrolidone (NOP),aqueous electrolyte system and (ii) the immiscible acetonitrile,aqueous electrolyte system. The influence of flow speed and liquid viscosity on the position of the phase boundary and mass transport-controlled limiting currents are examined. In contrast to the NOP,aqueous electrolyte case, the acetonitrile,aqueous electrolyte system is shown to behave close to ideal without ,undercutting' of the organic phase under the aqueous phase. The limiting current for three-phase boundary reactions is only weakly dependent on flow rate but directly proportional to the concentration and the diffusion coefficient in the organic phase. Acetonitrile as a commonly employed synthetic solvent is shown here to allow effective three-phase boundary processes to occur due to a lower viscosity enabling faster diffusion. N -butylferrocene is shown to be oxidised at the acetonitrile,aqueous electrolyte interface about 12 times faster when compared with the same process at the NOP,aqueous electrolyte interface. Conditions suitable for clean two-phase electrosynthetic processes without intentionally added supporting electrolyte in the organic phase are proposed. Copyright © 2008 John Wiley & Sons, Ltd. [source] Kinetics and mechanism of acid-catalyzed hydrolysis of the diazo functional group of diazophenylacetamideJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 9 2003J. A. Chang Abstract The acid-catalyzed hydrolysis of diazophenylacetamide giving mandelamide as product was found to occur with a normal (kH/kD>1) hydronium ion isotope effect and to be subject to general acid rather than specific hydronium ion catalysis. This shows that the reaction occurs by rate-determining hydron transfer from the catalyzing acid to the diazo carbon atom of the substrate, followed by rapid displacement of the diazo group by water. Comparison of the rate of this reaction with those of the same process for other diazophenylacetic acid functional derivatives, PhCN2COX, reveals that the reactivity of these substrates is controlled by the electron-releasing resonance ability of the group X. Copyright © 2003 John Wiley & Sons, Ltd. [source] Direct Synthesis of New Zircon-Type ZrGeO4 and Zr(Ge,Si)O4 Solid SolutionsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2002Masanori Hirano A new phase of ZrGeO4 was hydrothermally synthesized from a mixture of ZrOCl2 solution and GeO2 powder at 240°C. X-ray diffractometry patterns of synthesized ZrGeO4 particles, which had better crystallinity than ZrSiO4 particles prepared by the same process from ZrOCl2 and tetraethoxysilane, could be indexed for a zircon-type tetragonal structure, having a0= 0.6694(0) and c0= 0.6265(7) nm. The c/a ratio of synthesized ZrGeO4 (0.9360) was larger than that of ZrSiO4 (0.9054). Solid solutions with zircon-type structure over the whole composition range in the ZrGeO4 -ZiSiO4 system were also directly synthesized through the same solution route. The secondary particle size of zircon-type Zr(Ge,Si)O4 solid solutions decreased, and its morphology gradually changed from octahedron-like to blood-red cell-like with decreased GeO2 content. [source] Sintering and Microstructure Modification of Mullite/Zirconia Composites Derived from Silica-Coated Alumina PowdersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2001Viktor Yaroshenko This paper addresses the densification and microstructure development during firing of mullite/zirconia composites made from silica-coated-alumina (SCA) microcomposite powders. Densification occurs in two stages: in the presence of a silica,alumina mixture and after conversion to mullite. The first stage of densification occurs through transient viscous phase sintering (TVS). This is best promoted by rapid heating, which delays the crystallization of silica to higher temperatures. A further sintering stage is observed following mullitization. The introduction of seeds promotes solid-state sintering, most probably due to refinement of the mullite matrix. For seed concentrations up to about 1% the sintering kinetics depend on seed concentration. This suggests that nucleation still remains the rate-controlling mullitization step. Above this concentration the reaction becomes growth controlled. Introduction of seeds also promotes direct mullitization without transient zircon formation that was observed in a previous study of the same process without seeding. Seeding also promotes the development of elongated grains by way of a solid-state recrystallization process. [source] Post-pathological keel-loss compensation in ammonoid growthLETHAIA, Issue 1 2002ALAIN MORARD Among the various pathologies documented in ammonoids, impairs affecting the apertural margin may have long-lasting sequelae on subsequent shell geometry. An interesting healing pattern, known as sculptural compensation, led to the permanent replacement of an ornament by adjacent sculptural elements. Moreover, in several ventrally impaired individuals the symmetry was preserved. Those developed annular ribs in place of any previous ventral ornamentation (keel, sulcus or smooth area). This phenomenon is known from diverse ammonite families. Monestieria resouchei (Monestier 1931), type species of ,Monestieriinae' Sapunov 1965, displays exactly that type of annularly-ribbed morphology and has been shown to be otherwise similar to species of Grammoceratinae Buckman 1904 occurring in the same beds, thus corroborating its pathological nature and leading to the rejection of that taxon. Now, keel absence in Praehaploceras Monestier 1931 and Buckmanites Guex 1973 cannot be explained by the same process as they do not have annular ribs. Moreover, the absence of any clue of malformation, their relative frequency and specific characteristics exclude the previously suggested synonymies with Pseudolioceras Buckman 1889 as equivalent pathological forms. In consequence, their rehabilitation is herein proposed. They should be included within Harpoceratinae Neumayr 1875. [source] The metallographic cooling rate method revised: Application to iron meteorites and mesosideritesMETEORITICS & PLANETARY SCIENCE, Issue 1 2001W. D. HOPFE This revision incorporates a better fit to the ,/, + , phase boundary and to the ,/, + , phase boundary particularly below the monotectoid temperature of 400 °C. A reevaluation of the latest diffusivities for the Fe-Ni system as a function of Ni and P content and temperature is made, particularly for kamacite diffusivity below the paramagnetic to ferromagnetic transition. The revised simulation model is applied to several iron meteorites and several mesosiderites. For the mesosiderites we obtain a cooling rate of 0.2 °C/Ma, about 10x higher than the most recent measured cooling rates. The cooling rate curves from the current model do not accurately predict the central nickel content of taenite halfwidths smaller than ,10 ,m. This result calls into question the use of conventional kamacite growth models to explain the microstructure of the mesosiderites. Kamacite regions in mesosiderites may have formed by the same process as decomposed duplex plessite in iron meteorites. [source] Balancing move and work: women's labour market exits and entries after family migrationPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2006William A. V. Clark Abstract A substantial literature has examined the nature of mobility and migration and the link to workforce participation. In general that literature has documented the disadvantages to women who move or migrate with a partner during the mobility or migration process, but it suggests, especially for the US, that the disadvantage is temporarily limited. This study of the same process in the British labour market reaffirms a temporary deficit-effect of two-worker migration for women, but unlike the US labour market the process of re-entry seems slower. There are modest monetary gains from mobility and migration, but these gains come for some families only when women enter the labour force after migration. The study reconfirms the importance of gender in the migration and mobility processes. Income, for women, recovers more slowly if a birth was registered in the migration interval. Copyright © 2006 John Wiley & Sons, Ltd. [source] The crucial role of C,H...O and C=O..., interactions in the building of three-dimensional structures of dicarboxylic acid,biimidazole compoundsACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Xiao-Li Gao The supramolecular architectures of three dicarboxylic acid,biimidazole compounds, namely, 2,2,-biimidazolium malonate, C6H8N42+·C3H2O42,, (I), 2,2,-bi(1H -imidazole) succinic acid, C6H6N4·C4H6O4, (II), and 2,2,-biimidazolium 2,2,-iminiodiacetate chloride, C6H8N42+·C4H6NO4,·Cl,, (III), are reported. The crystal structures are assembled by the same process, namely double conventional N,H...O or O,H...N hydrogen bonds link the dicarboxylates and biimidazoles to form tapes, which are stacked in parallel through lone-pair,aromatic interactions between carbonyl O atoms and biimidazole groups and are further linked via weak C,H...O interactions. The C=O..., interactions involved in stacking the tapes in (II) and the C,H...O interactions involved in linking the tapes in (II) and (III) demonstrate the crucial role of these interactions in the crystal packing. There is crystallographically imposed symmetry in all three structures. In (I), two independent malonate anions have their central C atoms on twofold axes and two biimidazolium dications each lie about independent inversion centres; in (II), the components lie about inversion centres, while in (III), the unique cation lies about an inversion centre and the iminiodiacetate and chloride anions lie across and on a mirror plane, respectively. [source] A risk model driven by Lévy processesAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 2 2003Manuel Morales Abstract We present a general risk model where the aggregate claims, as well as the premium function, evolve by jumps. This is achieved by incorporating a Lévy process into the model. This seeks to account for the discrete nature of claims and asset prices. We give several explicit examples of Lévy processes that can be used to drive a risk model. This allows us to incorporate aggregate claims and premium fluctuations in the same process. We discuss important features of such processes and their relevance to risk modeling. We also extend classical results on ruin probabilities to this model. Copyright © 2003 John Wiley & Sons, Ltd. [source] Gaseous Ion Activation Dynamics: The Role of the Bulk Gas in the Racemization of Chiral Oxonium IonsCHEMPHYSCHEM, Issue 10 2004Antonello Filippi Dr. Abstract The kinetics of the inversion of configuration of a family of chiral oxonium ions, that is, O-protonated 1-aryl-1-methoxyethanes [YMe+], were investigated in two different gaseous media (in CH3X with X=F and X=Cl) at 720 torr of pressure and in the temperature range: 25,140,°C. The activation parameters of the [YMe+] inversion reaction were found to obey two different isokinetic relationships (IKR), depending on the nature and the position of the substituents in the oxonium ions and on the nature of the bulk gas employed. The observation of two IKR for the same family of reactions was related to a switchover in the resonant vibrational energy exchange between the reactants' critical mode, active in the transition state (,), and the discrete vibrational levels , of the bulk gas. In CH3F, this vibrational,vibrational coupling switchover concerns the out-of-plane CF,,,HO bending (the , family) and the H3CF stretching (the , family) modes in the proton-bound [CH3F,YMe+] complex. In CH3Cl, the coupling switchover concerns the out-of-plane CCl,,,HO bending (the , family) and the H3CCl methyl group rocking (the , family) modes in the proton-bound [CH3Cl,YMe+] complex. The [YMe+] activation dynamics also determine the inversion dynamics. The [YMe+]ret,[YMe+]invisomerization for the , family involves the same "thermodynamically most favorable" transition state in both the CH3F and the CH3Cl media, whereas the same process for the , family proceeds through different, dynamically favored transition states. [source] A succession of anesthetic endpoints in the Drosophila brainDEVELOPMENTAL NEUROBIOLOGY, Issue 11 2006Bruno van Swinderen Abstract General anesthetics abolish behavioral responsiveness in all animals, and in humans this is accompanied by loss of consciousness. Whether similar target mechanisms and behavioral endpoints exist across species remains controversial, although model organisms have been successfully used to study mechanisms of anesthesia. In Drosophila, a number of key mutants have been characterized as hypersensitive or resistant to general anesthetics by behavioral assays. In order to investigate general anesthesia in the Drosophila brain, local field potential (LFP) recordings were made during incremental exposures to isoflurane in wild-type and mutant flies. As in higher animals, general anesthesia in flies was found to involve a succession of distinct endpoints. At low doses, isoflurane uncoupled brain activity from ongoing movement, followed by a sudden attenuation in neural correlates of perception. Average LFP activity in the brain was more gradually attenuated with higher doses, followed by loss of movement behavior. Among mutants, a strong correspondence was found between behavioral and LFP sensitivities, thereby suggesting that LFP phenotypes are proximal to the anesthetic's mechanism of action. Finally, genetic and pharmacological analysis revealed that anesthetic sensitivities in the fly brain are, like other arousal states, influenced by dopaminergic activity. These results suggest that volatile anesthetics such as isoflurane may target the same processes that sustain wakefulness and attention in the brain. LFP correlates of general anesthesia in Drosophila provide a powerful new approach to uncovering the nature of these processes. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1195,1211, 2006 [source] PRECLINICAL STUDY: Effect of cannabinoids on platelet serotonin uptakeADDICTION BIOLOGY, Issue 2 2007Marie Velenovská ABSTRACT Serotonin is involved in many of the same processes affected by cannabinoids; therefore, we investigated in vitro and in vivo effects of these drugs on the function of serotonin transporter. The effect of ,9 -tetrahydrocannabinol (,9 -THC), endocannabinoid anandamide and synthetic cannabinoid receptor agonist WIN 55,212-2 on platelet serotonin uptake and membrane microviscosity was examined in 19 marijuana smokers and 20 controls. (1) Serotonin uptake was inhibited at higher doses of ,9 -THC (IC50 = 139 µmol/l), anandamide (IC50 = 201 µmol/l) or WIN 55,212-2 (IC50 = 17.4 µmol/l); the inhibition was found non-competitive. ,9 -THC, anandamide and WIN 55,212-2 produced different effects on the membrane microviscosity. (2) Maximal velocity of platelet serotonin uptake was significantly increased in a group of chronic marijuana smokers suffering impairment of cognitive functions when compared with controls. Opposite effect of marijuana smoking on the serotonin uptake efficiency was observed in males beside females. In summary, this study provides evidence that (1) Activity of serotonin transporter is acutely affected by cannabinoids at relatively high drug concentrations; this effect is indirect and can be partially accounted for the changes in the membrane microviscosity. (2) Increase of maximal velocity of the serotonin uptake could be understood as adaptation change in the serotonergic system induced by chronic cannabis use. A hypothesis was supported that lowered serotonin uptake may reflect a gender-related differences in effects of psychoactive cannabinoids. [source] Expectancy and Risk for Alcoholism: The Unfortunate Exploitation of a Fundamental Characteristic of Neurobehavioral AdaptationALCOHOLISM, Issue 5 2002Mark S. Goldman Psychological investigations of alcohol expectancies over the last 20 years, using primarily verbal techniques, have strongly supported expectancies as an important mediator of biological and environmental antecedent variables that influence risk for alcohol use and abuse. At the same time, rapid developments in neuroscience, cognitive science, affective science, computer science, and genetics proved to be compatible with the concept of expectancy and, in some cases, used this concept directly. By using four principles that bear on the integration of knowledge in the biological and behavioral sciences,consilience, conservation, contingency, and emergence,these developments are merged into an integrated explanation of alcoholism and other addictions. In this framework, expectancy is seen as a functional approach to adaptation and survival that has been manifested in multiple biological systems with different structures and processes. Understood in this context, addiction is not a unique behavioral problem or special pathology distinct from the neurobehavioral substrate that governs all behavior, but is rather a natural (albeit unfortunate) consequence of these same processes. The ultimate intent is to weave a working heuristic that ties together findings from molecular and molar levels of inquiry and thereby might help direct future research. Such integration is critical in the multifaceted study of addictions. [source] Using the Computer to Compare Foreign and Native Language Writing Processes: A Statistical and Case Study ApproachMODERN LANGUAGE JOURNAL, Issue 2 2000Helga Thorson Writing process research has attracted significant attention in English composition studies. However, much less research exists on the relationship between foreign language (FL) and first language (L1) writing processes. This study focuses on whether university students studying a FL (in this case German) at an American university use the same processes and writing strategies in FL and L1 writing in two different genres (letter and article). Using a computerized tracking device, individual writing sessions were analyzed through statistical techniques and individual case studies. Statistical results provided evidence that students wrote less, but revised more, when writing in the FL than in the L1. In their L1, students tended to revise less in the letter genre than when writing an article. The author advocates using the computer for writing process research, given that it is an unobtrusive and efficient method of data collection and because it provides researchers with an easy way to replicate research and to share data. [source] | |||||||||||||||||||||||||||||||||||||||||||