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Статті в журналах з теми "Heterogeneity of regimes"

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Meshcheryakov, Yuri, Alexandre Divakov, Natali Zhigacheva, and Boris Barakhtin. "Multiscale Deformation and Dynamic Recrystallization in Shock Deformed Aluminum Alloy." Materials Science Forum 794-796 (June 2014): 815–20. http://dx.doi.org/10.4028/www.scientific.net/msf.794-796.815.

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Two regimes, equilibrium and non-equilibrium interaction of shock wave and inner structure of solid are studied. The theoretical analysis of the regimes is carried out by using the concept of the meso-macro momentum exchange. As a test material for the experiments, D16 Al alloy is taken, firstly because of its initial heterogeneity in equilibrium regime of dynamic straining and, secondly, due to increasing heterogeneity in non-equilibrium regime. Shock tests of D16 Al alloy within impact velocity range of 85÷450m/sevidence that maximum dynamic strength is realized under conditions: (i) equilibrium regime of meso-macro momentum exchange, (ii) velocity defect equals to mean velocity variation. In non-equilibrium regime, the shock-induced dynamic recrystallization occurs, which is investigated with the metallography and X-ray analysis.
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Konovalov, Pavel, Daria Mangileva, Arsenii Dokuchaev, Olga Solovyova, and Alexander V. Panfilov. "Rotational Activity around an Obstacle in 2D Cardiac Tissue in Presence of Cellular Heterogeneity." Mathematics 9, no. 23 (November 30, 2021): 3090. http://dx.doi.org/10.3390/math9233090.

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Waves of electrical excitation rotating around an obstacle is one of the important mechanisms of dangerous cardiac arrhythmias occurring in the heart damaged by a post-infarction scar. Such a scar is also surrounded by the region of heterogeneity called a gray zone. In this paper, we perform the first comprehensive numerical study of various regimes of wave rotation around an obstacle surrounded by a gray zone. We use the TP06 cellular ionic model for human cardiomyocytes and study how the period and the pattern of wave rotation depend on the radius of a circular obstacle and the width of a circular gray zone. Our main conclusions are the following. The wave rotation regimes can be subdivided into three main classes: (1) functional rotation, (2) scar rotation and the newly found (3) gray zone rotation regimes. In the scar rotation regime, the wave rotates around the obstacle, while in the gray zone regime, the wave rotates around the gray zone. As a result, the period of rotation is determined by the perimeter of the scar, or gray zone perimeter correspondingly. The transition from the scar to the gray rotation regimes can be determined from the minimal period principle, formulated in this paper. We have also observed additional regimes associated with two types of dynamical instabilities which may affect or not affect the period of rotation. The results of this study can help to identify the factors determining the period of arrhythmias in post-infarction patients.
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Duflot, R., K. Eyvindson, and M. Mönkkönen. "Management diversification increases habitat availability for multiple biodiversity indicator species in production forests." Landscape Ecology 37, no. 2 (November 29, 2021): 443–59. http://dx.doi.org/10.1007/s10980-021-01375-8.

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Abstract Context Forest biodiversity is closely linked to habitat heterogeneity, while forestry actions often cause habitat homogenization. Alternative approaches to even-aged management were developed to restore habitat heterogeneity at the stand level, but how their application could promote habitat diversity at landscape scale remains uncertain. Objectives We tested the potential benefit of diversifying management regimes to increase landscape-level heterogeneity. We hypothesize that different styles of forest management would create a diverse mosaic of forest habitats that would in turn benefit species with various habitat requirements. Methods Forest stands were simulated under business-as-usual management, set-aside (no management) and 12 alternative management regimes. We created virtual landscapes following diversification scenarios to (i) compare the individual performance of management regimes (no diversification), and (ii) test for the management diversification hypothesis at different levels of set-aside. For each virtual landscape, we evaluated habitat availability of six biodiversity indicator species, multispecies habitat availability, and economic values of production. Results Each indicator species responded differently to management regimes, with no single regime being optimal for all species at the same time. Management diversification led to a 30% gain in multispecies habitat availability, relative to business-as-usual management. By selecting a subset of five alternative management regimes with high potential for biodiversity, gains can reach 50%. Conclusions Various alternative management regimes offer diverse habitats for different biodiversity indicator species. Management diversification can yield large gains in multispecies habitat availability with no or low economic cost, providing a potential cost-effective biodiversity tool if the management regimes are thoughtfully selected.
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Boulanger, Yan, Sylvie Gauthier, and Philip J. Burton. "A refinement of models projecting future Canadian fire regimes using homogeneous fire regime zones." Canadian Journal of Forest Research 44, no. 4 (April 2014): 365–76. http://dx.doi.org/10.1139/cjfr-2013-0372.

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Broad-scale fire regime modelling is frequently based on large ecological and (or) administrative units. However, these units may not capture spatial heterogeneity in fire regimes and may thus lead to spatially inaccurate estimates of future fire activity. In this study, we defined homogeneous fire regime (HFR) zones for Canada based on annual area burned (AAB) and fire occurrence (FireOcc), and we used them to model future (2011–2040, 2041–2070, and 2071–2100) fire activity using multivariate adaptive regression splines (MARS). We identified a total of 16 HFR zones explaining 47.7% of the heterogeneity in AAB and FireOcc for the 1959–1999 period. MARS models based on HFR zones projected a 3.7-fold increase in AAB and a 3.0-fold increase in FireOcc by 2100 when compared with 1961–1990, with great interzone heterogeneity. The greatest increases would occur in zones located in central and northwestern Canada. Much of the increase in AAB would result from a sharp increase in fire activity during July and August. Ecozone- and HFR-based models projected relatively similar nationwide FireOcc and AAB. However, very high spatial discrepancies were noted between zonations over extensive areas. The proposed HFR zonation should help providing more spatially accurate estimates of future ecological patterns largely driven by fire in the boreal forest such as biodiversity patterns, energy flows, and carbon storage than those obtained from large-scale multipurpose classification units.
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Neri, Franco M., Francisco J. Pérez-Reche, Sergei N. Taraskin, and Christopher A. Gilligan. "Heterogeneity in susceptible–infected–removed (SIR) epidemics on lattices." Journal of The Royal Society Interface 8, no. 55 (July 14, 2010): 201–9. http://dx.doi.org/10.1098/rsif.2010.0325.

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The percolation paradigm is widely used in spatially explicit epidemic models where disease spreads between neighbouring hosts. It has been successful in identifying epidemic thresholds for invasion, separating non-invasive regimes, where the disease never invades the system, from invasive regimes where the probability of invasion is positive. However, its power is mainly limited to homogeneous systems. When heterogeneity (environmental stochasticity) is introduced, the value of the epidemic threshold is, in general, not predictable without numerical simulations. Here, we analyse the role of heterogeneity in a stochastic susceptible–infected–removed epidemic model on a two-dimensional lattice. In the homogeneous case, equivalent to bond percolation, the probability of invasion is controlled by a single parameter, the transmissibility of the pathogen between neighbouring hosts. In the heterogeneous model, the transmissibility becomes a random variable drawn from a probability distribution. We investigate how heterogeneity in transmissibility influences the value of the invasion threshold, and find that the resilience of the system to invasion can be suitably described by two control parameters, the mean and variance of the transmissibility. We analyse a two-dimensional phase diagram, where the threshold is represented by a phase boundary separating an invasive regime in the high-mean, low-variance region from a non-invasive regime in the low-mean, high-variance region of the parameter space. We thus show that the percolation paradigm can be extended to the heterogeneous case. Our results have practical implications for the analysis of disease control strategies in realistic heterogeneous epidemic systems.
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Arce M., Daniel G. "The Evolution of Heterogeneity in Biodiversity and Environmental Regimes." Journal of Conflict Resolution 44, no. 6 (December 2000): 753–72. http://dx.doi.org/10.1177/0022002700044006003.

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Marcoux, Hélène M., Sarah E. Gergel, and Lori D. Daniels. "Mixed-severity fire regimes: How well are they represented by existing fire-regime classification systems?" Canadian Journal of Forest Research 43, no. 7 (July 2013): 658–68. http://dx.doi.org/10.1139/cjfr-2012-0449.

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Maps depicting historic fire regimes provide critical baselines for sustainable forest management and wildfire risk assessments. However, given our poor understanding of mixed-severity fire regimes, we asked if there may be considerable errors in fire-regime classification systems used to create landscape-level maps. We used dendrochronological field data (fire scars and tree establishment dates) from 20 randomly selected sites in southern British Columbia to evaluate two classification systems (Natural Disturbance Type (NDT) and Historical Natural Fire Regime (HNFR)) used by managers to map fire regimes. We found evidence of mixed-severity fires at 55% of sites. Each classification system made considerable and contrasting errors predicting mixed-severity regimes (relative to field data), and the discrepancies varied with elevation. The NDT system underrepresented low-to-moderate-severity fires at lower elevations, whereas the HNFR system overpredicted their occurrence at higher elevations. Errors are attributed to underlying assumptions about disturbances in the two classification systems, as well as limitations of the research methods used to estimate fire frequency in mixed-severity regimes (i.e., methods more relevant to high- versus low-severity regimes). Ecological heterogeneity created by mixed-severity regimes potentially influences decisions related to conservation, silviculture, wildfire, and fuel mitigation. Thus, understanding underlying assumptions and errors in mapping fire regimes is critical.
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Roos, Williamson, and Bowman. "Is Anthropogenic Pyrodiversity Invisible in Paleofire Records?" Fire 2, no. 3 (July 18, 2019): 42. http://dx.doi.org/10.3390/fire2030042.

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Paleofire studies frequently discount the impact of human activities in past fire regimes. Globally, we know that a common pattern of anthropogenic burning regimes is to burn many small patches at high frequency, thereby generating landscape heterogeneity. Is this type of anthropogenic pyrodiversity necessarily obscured in paleofire records because of fundamental limitations of those records? We evaluate this with a cellular automata model designed to replicate different fire regimes with identical fire rotations but different fire frequencies and patchiness. Our results indicate that high frequency patch burning can be identified in tree-ring records at relatively modest sampling intensities. However, standard methods that filter out fires represented by few trees systematically biases the records against patch burning. In simulated fire regime shifts, fading records, sample size, and the contrast between the shifted fire regimes all interact to make statistical identification of regime shifts challenging without other information. Recent studies indicate that integration of information from history, archaeology, or anthropology and paleofire data generate the most reliable inferences of anthropogenic patch burning and fire regime changes associated with cultural changes.
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Miller, Carol, and Dean L. Urban. "Interactions between forest heterogeneity and surface fire regimes in the southern Sierra Nevada." Canadian Journal of Forest Research 29, no. 2 (February 1, 1999): 202–12. http://dx.doi.org/10.1139/x98-188.

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Fire is a major agent of spatial pattern formation in forests, as it creates a mosaic of burned and unburned patches. While most research has focused on landscape-level patterns created by crown fires, millions of hectares of forests in North America are subject to surface fire regimes. A spatially explicit forest gap model developed for the Sierra Nevada was used to evaluate the influence of surface fire regimes on the heterogeneity of forest structure and composition within forest stands. Forest pattern was evaluated for a wide range of topographic positions in Sequoia National Park, California, to determine if repeated surface fires amplify existing spatial patterns. The spatial heterogeneity of some forest characteristics increased under a simulated fire regime relative to scenarios without fire. Although a distinct and regular fire-generated spatial pattern was not detected with an analysis of spatial autocorrelation, simulated surface fires did alter the spatial heterogeneity within a forest stand, primarily by degrading a regular structure that is imposed by competition for light in the absence of fire. The interaction between surface fires and forest pattern may be qualitatively different from that which occurs in forests subject to crown fires. As such, what has been learned about forests dominated by crown fires may not apply to forests subject to surface fire regimes.
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Gapontsev, V. L., Valerie M. Koloskov, and M. G. Gapontseva. "Generalization of Fisher Model for Periodically Non-Uniform Grain Boundary." Defect and Diffusion Forum 277 (April 2008): 213–20. http://dx.doi.org/10.4028/www.scientific.net/ddf.277.213.

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The problem of grain boundary diffusion for a case of boundary grain with periodic heterogeneity diffusion properties is considered. Dependence of Laplace transform images of impurity concentration on various diffusion conductivity places is built. The dimensionless parameters, forming the system of grain boundary diffusion regimes are determined. The space (ln x,lnt,1/T) is divided into areas in which the ratio ln ln ~ ln ln ( / ) ln eff o C r x−k t− Q RT − A is maintained, when the parameters of diffusion regime are constant. The values of parameters , , , eff o r k Q A fully specify the diffusion regimes. On this base the new concept for the definition of grain boundary diffusion regimes is carried out and the method for construction of simplified tracer concentration profile is proposed.
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Дисертації з теми "Heterogeneity of regimes"

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Guo, Lian W. "Effects of Variable and Constant Acclimation Regimes on the Upper Thermal Tolerance of Intertidal Barnacle, Balanus Glandula." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/331.

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As a unique habitat that encompasses steep environmental gradients, it is important to evaluate threats posed to the intertidal zone by rapid climate change. It is thought that intertidal ectotherms are living close to their physiological limit; therefore slight changes in temperature could result in high levels of mortality. Past studies on intertidal species measured thermal tolerance under constant temperatures, neglecting to consider the impacts of natural variation in field temperatures. I conducted a study on the barnacle, Balanus glandula, to assess if a variable thermal environment would alter thermal tolerance. Barnacles were acclimated in an intertidal mesocosm to either daily cold (maximum 20.4◦C), daily warm (maximum 26.5◦C), or variable (two days cold, two days warm) low-tide temperatures. I measured each barnacle’s critical thermal maximum (CTmax) by increasing air temperature 6◦C/hour and identifying the point at which the barnacle ceased to function. Barnacles exposed to any warm temperatures demonstrated an increased thermal tolerance, suggesting that this population of barnacles is capable of shifting their thermal maximum. Furthermore, acclimation to thermal heterogeneity raised thermal maximum, reinforcing the need for future thermal tolerance studies to incorporate biologically-relevant thermal regimes in laboratory experiments. These results demonstrate that B. glandula in the field are well-adapted for increasing air temperatures.
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Chelova, Mariya. "Divided we stand." Doctoral thesis, Humboldt-Universität zu Berlin, Philosophische Fakultät III, 2012. http://dx.doi.org/10.18452/16563.

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Nach dem Zusammenbruch der Sowjetunion stellte der Aufbau eines unabhängigen Staates und einer unabhängigen Nation eine große Herausforderung für die Regierenden der fünfzehn ehemaligen Sowjetrepubliken dar Zwanzig Jahre später, pendelt der Typus, der aus jenen Prozessen hervorgegangenen politischen Regime, zwischen Demokratie und Autokratie. Diese Dissertation konzentriert sich auf die Grauzone zwischen diesen beiden Idealtypen, d.h. auf ‚hybride Regime‘, verstanden als Staaten, die nachweislich freie und faire Wahlen einerseits mit einem autokratischen Regierungsstil andererseits kombinieren. Unter den ehemaligen Sowjetrepubliken sind dies Georgien, Moldawien und die Ukraine. Die zentrale Frage der Arbeit lautet, welche Faktoren die Funktionstüchtigkeit dieser Regime gewährleistet. Es zeigt sich, dass die drei genannten Länder ethnisch stark heterogen sind relative arme Volkswirtschaften mit sehr schwachem Wachstum sind. Es wird argumentiert, dass es diese beiden Strukturmerkmale sind, die das Handeln der heimischen Eliten wesentlich determinieren und die, zusammen mit den durch internationale Geldgeber gesetzten Anreizen, die Dauerhaftigkeit dieser hybriden Regime bedingen. Dagegen steht die politische Polarisierung im Kern des Erklärungsmodells dieser Dissertation. Im Detail sieht das Erklärungsmodell vor, dass sie diesen Einfluss vermittelt durch das Moment der politischen Polarisierung ausüben. Ethnische Spaltungen spiegeln sich in polarisierten politischen Gruppierungen wieder und sind dadurch für einen hochgradig kompetitiven Charakter von Wahlen verantwortlich. Die heimischen Eliten betonen ethnische Antagonismen in ihren Wahlkämpfen und auch die internationalen Geldgeber schüren eine bereits latent konfliktreiche Atmosphäre. Dieses Verhaltensschema sichert den Fortbestand der hybriden Regime in Moldawien und der Ukraine. Die Abwesenheit von Polarisierung, die auf einer leicht entflammbaren Fragen basiert, resultiert in einem Mangel an Kompetitivität.
In the aftermath of the breakdown of the Soviet Union, the leadership in the fifteen former republics found themselves challenged by complex processes of independent state- and nation-building. Twenty years later, the political regimes that emerged vary from democracies to autocracies. This dissertation focuses on the grey zone in between the pure types. Conceptualizing hybrid regimes as the ones that combine holding of free and fair, recognized elections, and autocratic governance, it asks the question of what keeps the former viable. This research singles out Georgia, Moldova and Ukraine as the countries with hybrid regimes. It shows that the three are highly ethnically heterogeneous and have relatively poor, very low-growing economies. This dissertation argues that these structural conditions are responsible for the actions of the domestic elites, which together with the incentives that the international donors provide the domestic elites with make hybrid regimes permanent. The political polarization is at the core of the explanatory account this dissertation presents. Ethnic divisions, reflected in political polarization are responsible for emergence of regimes with competitive elections. The elites emphasize the divisive issues in their campaigning, while the donors support the already thriving competitive environment. This keeps competitive hybrid regimes in Moldova and Ukraine viable. Absence of polarization based on easily inflammable issues results in the lack of competitiveness. However, an absence of divisiveness produces orientation on one vector of donors (the West). The stimulation of reform and praise for achievement in governance that the donors provide keep the non-competitive hybrid regime in Georgia afloat.
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Leale, Alanna M. "The Emergence, Maintenance and Demise of Diversity in a Spatially Variable Antibiotic Regime." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36689.

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Antimicrobial resistance is a serious and imminent threat to human health, though its rise may be controlled with improved stewardship strategies that limit the emergence and spread of resistant strains. Motivated by theoretical models from population genetics and ecology, my M.Sc. experimentally evaluates how varying drug availability in either time or space impacts the prevalence of resistance in a population. By experimentally evolving Pseudomonas aeruginosa under different antibiotic selection regimes in vitro, I show that spatial, but not temporal, drug free refuges delay the fixation of resistance by promoting the coexistence of sensitive and resistant genotypes. Second, I establish that this polymorphism is underlain by a trade-off between resistance and growth rate in the absence of antibiotic that underpins the maintenance of diversity through negative frequency dependent selection. Third, I demonstrate that spatially varied drug selection cannot prevent the fixation of resistance because continued selection leads to the evolution of resistant types that pay smaller costs of resistance and gradually displace sensitive strains. These results provide insight into the fate of diversity under long-term selection and highlight the value of incorporating the principles of evolutionary ecology into antimicrobial resistance stewardship.
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Alvarez, Martinez José Manuel. "Foam-flow behavior in porous media : effects of flow regime and porous-medium heterogeneity /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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Walker, Scott. "Does Cultural Heterogeneity Lead to Lower Levels of Regime Respect for Basic Human Rights?" Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3303/.

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This dissertation is a cross-national investigation of the relationship between cultural heterogeneity and regimes' respect for basic human rights. The quantitative human rights literature has not yet addressed the question of whether high levels of cultural diversity are beneficial or harmful. My research addresses this gap. I address the debate between those who argue that diversity is negatively related to basic human rights protection and those who argue it is likely to improve respect for these rights. Ultimately, I propose that regimes in diverse countries will be less likely to provide an adequate level of subsistence (otherwise known as basic human needs) and security rights (also known as integrity of the person rights) to their citizens than regimes in more homogeneous countries. Using a data set of 106 non-OECD countries for the years 1983 and 1993, I employ bivariate, linear multivariate regression, and causal modeling techniques to test whether higher levels of ethnolinguistic and religious diversity are associated with less regime respect for subsistence and security rights. The analysis reveals that higher levels of cultural diversity do appear to lead to lower respect for subsistence rights. However, counter to the hypothesized relationship, high levels of diversity appear to be compatible with high levels of respect for security rights.
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Earon, Robert. "Water supply in hard rock coastal regions : The effect of heterogeneity and kinematic porosity." Licentiate thesis, KTH, Mark- och vattenteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143647.

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Water resources in hard rock terrain are difficult to characterize due to heterogeneity and anisotropy in the fracture network, low porosities and limited recharge volumes available during the summer season. Three methods were developed and evaluated in order to assist in water supply planning. A groundwater resources potential index was estimated using multivariate statistics, where physical and geological variables were classified using Analysis of Variance and Fisher's Least Significant Difference tests according to their effect on hydraulic properties. Principal component analysis was used to assign weights to the different classed variables. Classes and weights were used to produce an index referred to as groundwater resources potential (GRP), which correlated significantly with well data. Nearly 80% of the wells with less than median specific capacity values also had GRP values at those locations of zero or lower. Non-stationary variance was observed in specific capacity sub-samples taken from the Geological Survey of Sweden's well archive, despite homogeneous geology and topography. Spatial statistical analyses showed that spatial correlations were weak in well archive samples, implying that regional approximations based on sparse point data are highly error prone. Kinematic porosity estimated using superficial fracture measurements correlated significantly with well archive data. However, low correlation coefficients indicated that well data is likely not a suitable method for predicting water supply characteristics. This approach is an efficient method which shows promise in preliminary estimations of groundwater storage in heterogenic terrains. A groundwater balance model which describes seasonal groundwater storage changes was created in order to better approximate the groundwater situation often found in Swedish urbanized and semi-urbanized hard rock terrains. The model was based on a water budget approach at the pixel scale, and allows for approximation of well extraction which is not uniformly distributed in space. The model showed that in specific regions groundwater extraction may lead to severe decreases in groundwater level, where these impacts may not otherwise be expected. Dry season modelling with 10% increased evapotranspiration showed that in several areas groundwater reservoir depletion may be influenced by more than 50%.

QC 20140331

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Nowotny, Klaus, and Dieter Pennerstorfer. "Network migration: do neighbouring regions matter?" Routledge by Taylor & Francis Group, 2019. http://dx.doi.org/10.1080/00343404.2017.1380305.

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This paper analyses the role of the spatial structure of migrant networks in the location decision of migrants to the European Union at the regional level. Using a random parameters logit specification, a significant positive effect of migrant networks in neighbouring regions on migrants' location decisions is found. Although this spatial spillover effect is smaller than the effect of networks in the host regions, omitting to control for this spatial dependence results in a 40% overestimation of the effect of regional migrant networks on the location decision of newly arriving migrants.
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Nguyen, David. "The geography of firm internationalisation in Germany : exploring domestic and foreign heterogeneity across regions and sectors." Thesis, London School of Economics and Political Science (University of London), 2017. http://etheses.lse.ac.uk/3671/.

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The present thesis explores the internationalisation of firms in relation to regionsector characteristics. We focus on outward investment by German firms and classify the heterogeneity across firms, regions and sectors, as well as foreign destinations. The thesis is structured in 5 chapters: a general introduction, followed by 3 empirical chapters and a final conclusion. In the introductory chapter we provide a general conceptual framework and selective review of the literature. Our starting point is that internationalisation is heterogenous across firms as it requires ownership advantages. However, the source of these is less explored and we discuss how regional factors such as the proximity to MNEs can influence foreign expansions. Conceptually we rely on spillover and competition effects and put forward that MNEs can act as catalysts for internationalising domestic firms. Chapter 2 analyses the propensity of German firms to be active as outward investors, exploring and qualifying the heterogeneity across firms, regions and sectors. We find that different forms of proximity matter for the intensive and extensive margins of outward investment by German firms. First, region-sector co-location with MNEs is more important than regional co-location. This lends support to the notion of technological proximity as a facilitator of spillovers. Second, the association between region-sector proximity and the propensity of firms to invest abroad is larger at finer spatial scales. This hints to the tacitness of some knowledge and information about internationalisation processes, as these types of effects and externalities mainly arise between spatially proximate firms. Third, region-sector proximity is shown to matter most when the firm and the proximate MNE are both German-owned. It highlights a potential role of cultural proximity and regional embeddedness for positive externalities or feedback loops to occur. Chapter 3 enquires how destination-specific ties available in the home region in Germany can be leveraged by the internationalising firm when making location decisions abroad. We provide empirical evidence on this by using data on inward and outward investment linkages and migrant networks between a German region and foreign destination. Our findings also reveal that those matter more for likely first-time investors, while within business group experience is not shown to play a role. Using a mixed logit model we further highlight significant heterogeneity across firms in their directionality of outward investments. Larger firms are found to be able to expand to more distant foreign destinations while smaller firms mainly choose European locations. Chapter 4 turns our focus to whole sectors and compares their domestic and global geography. To do so we use detailed geocoded data on the global locations of German manufacturing firms. We reveal that also at the global level there is considerable heterogeneity in the spatial pattern across sectors. The concentration ’intensity’ is also generally higher than at the domestic level and the level of technology in a sector plays a key role for its pattern. While at the domestic level high-tech sectors are found to be the most concentrated, at the global level it is rather low and medium-low tech sectors. At the same time, firms in medium-high tech sectors are the least concentrated in both. As they are often referred to as the ’backbone’ of the German economy, we see potential implications for territorial cohesion and regional disparities.
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Lipinski, Victor Mendes. "ESTRUTURA ESPACIAL DE COMUNIDADES DE ANUROS DE DUAS REGIÕES FISIOGRÁFICAS DO BIOMA PAMPA." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/5299.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
In this study, we sampled two anuran communities in two physiographic regions of the Pampa biome, Serra do Sudeste and Depressão Central, were made monthly campaigns during the period between September 2011 and August 2012 where there were registered 25 species of frogs. Scinax granulatus, Physalaemus gracilis e Pseudis minuta were the most abundant species in the Serra do Sudeste, while Dendropsophus minutus, D. sanborni and Scinax squalirostris were the most abundant of the Depressão Central. We recorded 15 species of frogs in the larval stage and four reproductive modes classified as generalists. Ordination analysis showed a segregation among the two physiographic regions, related to anurofauna with a difference of 65% between them. The influence of environmental descriptors and physicochemical variables of water in the structure of the two communities showed that the set of variables, pH, number of extracts of emergent vegetation and temperature were important in structuring the community of Depressão Central, as dissolved oxygen, electrical conductivity number of extracts of emergent vegetation, hydroperiod and percentage of vegetation cover were important factors structuring the community of Serra do Sudeste. However the abundance and richness of the Serra do Sudeste community showed no significant relation with the variables tested and the distance between the puddles did not influence the structure of both communities.
Neste estudo, foram amostradas duas comunidades de anuros em duas regiões fisiográficas do bioma Pampa, a Serra do Sudeste e a Depressão Central, nestas, foram realizadas campanhas mensais durante o período de setembro de 2011 a agosto de 2012 onde foram registradas 25 espécies de anuros. Scinax granulatus, Physalaemus gracilis e Pseudis minuta foram as espécies mais abundantes na Serra do Sudeste, enquanto Dendropsophus minutus, D. sanborni e Scinax squalirostris foram as mais abundantes da Depressão Central. Foram registrados 15 espécies de anuros em estágio larval e quatro modos reprodutivos generalistas. A análise de ordenação mostrou uma segregação quanto a anurofauna das duas regiões fisiográficas e uma diferença de 65% entre elas. A influência dos descritores ambientais e das variáveis físico-químicas da água na estrutura das duas comunidades mostrou que o conjunto de variáveis, pH, número de extratos de vegetação emergente e temperatura foram importantes na estruturação da comunidade da Depressão Central, já o oxigênio dissolvido, condutividade elétrica número de extratos de vegetação emergente, hidroperíodo e porcentagem de cobertura vegetal foram importantes estruturadores da comunidade da Serra do Sudeste. A abundância e a riqueza de anuros da Serra do Sudeste não apresentou relação significativa com as variáveis testadas e a distância entre as poças não influenciou na estrutura das mesmas.
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Belhadj, Aram. "L'intégration monétaire et les pays émergents : application au Maghreb." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE0501.

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Cette thèse s’intéresse à l’option de création d’une union monétaire entre les trois pays du Maghreb, àsavoir l’Algérie, le Maroc et la Tunisie. Elle essaye de répondre aux interrogations suivantes : quelles sont lescaractéristiques des régimes monétaires des pays du Maghreb et comment leurs choix sont-ils justifiés ? Les structures et lesinstitutions de ces pays les rendent-ils éligibles à une union monétaire ? Quelles conséquences macroéconomiques ces payspourront-ils supporter s’ils décident de créer cette union ? Existe-t-il des régimes monétaires alternatifs plus appropriés leursfacilitant in fine la transition vers l’étape ultime de l’intégration monétaire ?Afin de répondre à ces questions, nous avons opté pour la présentation de quatre chapitres. Nous avons décritdans un premier chapitre les fondements théoriques de l’intégration monétaire à travers l’étude de la théorie desZones Monétaires Optimales (ZMO), ses développements, ses lacunes, ses prolongements et ses applicationsempiriques. Nous avons tenté dans un deuxième chapitre de spécifier les mécanismes structurels et institutionnelssusceptibles de garantir la viabilité du processus d’intégration monétaire et de faire recours à quelques expérienceshistoriques. Nous avons essayé dans un troisième chapitre de décrire les régimes monétaires pratiqués par lespays du Maghreb et d’expliquer l’origine de leur hétérogénéité avant d’expliciter les possibilités de création d’uneZMO en présence de cette hétérogénéité. Enfin, nous avons cherché dans un quatrième chapitre à évaluer lesconséquences de la création d’une union monétaire entre les trois pays. Nous avons aussi proposé les régimesmonétaires envisageables qui leur permettent in fine une transition réussie vers cette union monétaire.Nos principaux résultats montrent que la création d’une union monétaire -et son corollaire la mise en place d’unerègle monétaire commune- n’est pas bénéfique, surtout pour l’Algérie du fait que la variabilité de l’inflation et del’activité est beaucoup plus importante qu’au Maroc ou en Tunisie. D’autre part, il a été convenu quel’harmonisation des cibles d’inflation dans le cadre d’un taux de change quasi-flexible ou l’instauration simultanéed’une caisse d’émission pourraient être des régimes monétaires appropriés permettant à ces trois pays unetransition réussie vers l’unification monétaire
This thesis focuses on the option of the launching of a monetary union across three Maghreb Countries, notablyAlgeria, Morocco and Tunisia. It tries to answer the following questions: What are the characteristics of monetaryregimes in the Maghreb Countries and what are the underlying factors for their choices? Do the countries’ structures andinstitutions constitute a favourable environment for the creation of a monetary union between these countries? What would bethe macroeconomic consequences for these countries if they decided to create a monetary union? Are there any alternativemonetary regimes which would enable them to move toward the final steps of monetary integration in a more appropriate way?In order to answer these questions, we opted for a presentation of four chapters. In a first chapter, we describedthe theoretical foundations of monetary integration through the study of Optimum Currency Area Theory (OCA),their theoretical developments, their drawbacks, their extensions and their empirical applications. We tried in asecond chapter to present the structural and institutional mechanisms that insure the viability of the monetaryintegration process and to recourse to some historical experiences. We attempted in a third chapter to describe themonetary regimes currently in use in the Maghreb Countries and to explain the origin of their heterogeneity beforeanalyzing the possibility of setting up an OCA in this context of heterogeneity. Finally, in a fourth chapter, weassessed the consequences of the creation of a monetary union across the three countries. We also suggest possiblemonetary regimes which, in fine, might allow these countries to successfully move toward monetary union.Our main results show that the creation of a monetary union –and its corollary the implementation of a commonmonetary rule- is not beneficial, especially for Algeria where the variability of inflation and activity is moreimportant than in Morocco and Tunisia. On the other hand, we came to the conclusion that the harmonization ofinflation targets within a quasi-flexible exchange rate or the simultaneous setting up of a currency board in thesecountries could represent an appropriate monetary regime which would allow a safe move to monetary union
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Книги з теми "Heterogeneity of regimes"

1

Eaton, Kent. Introduction. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198800576.003.0001.

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In addition to conceptualizing the two types of subnational policy challenges that are examined in the book, this introductory chapter explores the distinctive possibilities and limitations of subnational neoliberalism and subnational statism as two prominent types of subnational policy regimes. It also examines the causes that have made subnational policy challenges more common around the world today and specifically within Latin America, including globalization, democratization, decentralization, party system collapse, and indigenous mobilization. Next, the chapter assesses the importance of the shift toward greater territorial heterogeneity by analyzing the possible advantages and disadvantages of this shift, including when it results in cases of policy regime juxtaposition. The chapter ends with a brief overview of the theoretical framework, which stresses the importance of structural, institutional, and coalitional factors to explain variation in the success of subnational policy challenges.
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2

Spectroscopic evidence against nitric accide trlhydrate in polar stratospheric clouds. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1995.

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3

Kotagal, Vikas, and Praveen Dayalu. Parkinson Syndromes. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0005.

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Progressive supranuclear palsy (PSP) is a neurodegenerative condition characterized by axial motor features, oculomotor abnormalities, and cognitive dysfunction. PSP is characterized by progressive tau deposition with neuronal loss in cortical and subcortical regions. The underlying etiology of PSP may reflect complex gene-environment interactions, though genetic heterogeneity in the microtubule-associated protein tau (MAPT) gene can confer increased risk. Clinical care of patients with PSP focuses on minimizing motor and non-motor morbidity using available symptomatic therapies.
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4

Gao, Yanhong, and Deliang Chen. Modeling of Regional Climate over the Tibetan Plateau. Oxford University Press, 2017. http://dx.doi.org/10.1093/acrefore/9780190228620.013.591.

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The modeling of climate over the Tibetan Plateau (TP) started with the introduction of Global Climate Models (GCMs) in the 1950s. Since then, GCMs have been developed to simulate atmospheric dynamics and eventually the climate system. As the highest and widest international plateau, the strong orographic forcing caused by the TP and its impact on general circulation rather than regional climate was initially the focus. Later, with growing awareness of the incapability of GCMs to depict regional or local-scale atmospheric processes over the heterogeneous ground, coupled with the importance of this information for local decision-making, regional climate models (RCMs) were established in the 1970s. Dynamic and thermodynamic influences of the TP on the East and South Asia summer monsoon have since been widely investigated by model. Besides the heterogeneity in topography, impacts of land cover heterogeneity and change on regional climate were widely modeled through sensitivity experiments.In recent decades, the TP has experienced a greater warming than the global average and those for similar latitudes. GCMs project a global pattern where the wet gets wetter and the dry gets drier. The climate regime over the TP covers the extreme arid regions from the northwest to the semi-humid region in the southeast. The increased warming over the TP compared to the global average raises a number of questions. What are the regional dryness/wetness changes over the TP? What is the mechanism of the responses of regional changes to global warming? To answer these questions, several dynamical downscaling models (DDMs) using RCMs focusing on the TP have recently been conducted and high-resolution data sets generated. All DDM studies demonstrated that this process-based approach, despite its limitations, can improve understandings of the processes that lead to precipitation on the TP. Observation and global land data assimilation systems both present more wetting in the northwestern arid/semi-arid regions than the southeastern humid/semi-humid regions. The DDM was found to better capture the observed elevation dependent warming over the TP. In addition, the long-term high-resolution climate simulation was found to better capture the spatial pattern of precipitation and P-E (precipitation minus evapotranspiration) changes than the best available global reanalysis. This facilitates new and substantial findings regarding the role of dynamical, thermodynamics, and transient eddies in P-E changes reflected in observed changes in major river basins fed by runoff from the TP. The DDM was found to add value regarding snowfall retrieval, precipitation frequency, and orographic precipitation.Although these advantages in the DDM over the TP are evidenced, there are unavoidable facts to be aware of. Firstly, there are still many discrepancies that exist in the up-to-date models. Any uncertainty in the model’s physics or in the land information from remote sensing and the forcing could result in uncertainties in simulation results. Secondly, the question remains of what is the appropriate resolution for resolving the TP’s heterogeneity. Thirdly, it is a challenge to include human activities in the climate models, although this is deemed necessary for future earth science. All-embracing further efforts are expected to improve regional climate models over the TP.
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5

Samuels, Jack, Marco A. Grados, Elizabeth Planalp, and O. Joseph Bienvenu. Genetic Understanding of OCD and Spectrum Disorders. Edited by Gail Steketee. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780195376210.013.0025.

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This chapter reviews the evidence for the genetic etiology of OCD and spectrum conditions. A genetic basis is supported by the familial aggregation of OCD; evidence for involvement of genes of major effect in segregation analyses; and higher concordance for OCD in identical than non-identical twins. Recent studies also support linkage of OCD to specific chromosomal regions and association of OCD with specific genetic polymorphisms. However, specific genes causing OCD have not yet been firmly established. The search for genes is complicated by the clinical and etiologic heterogeneity of OCD, as well as the possibility of gene–gene and gene–environmental interactions. Despite this complexity, developments in molecular and statistical genetics, and further refinement of the phenotype hold promise for further deepening our genetic understanding of OCD and spectrum disorders in the coming decade.
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6

Zhou, Juan, and William W. Seeley. Brain Circuits. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190233563.003.0007.

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Each neurodegenerative disease is defined by selectively vulnerable neurons, regions, networks, and functions, as well as genetic risk factors. In the past decade, new network-sensitive neuroimaging methods have made it possible to test the notion of network-based degeneration in living humans. This chapter focuses on two common causes of dementia, Alzheimer’s disease (AD) and frontotemporal dementia (FTD), but uses these diseases to illustrate class-wide neurodegeneration principles whenever possible. It first introduces two key concepts of neurodegenerative disease selective vulnerability: onset and progression. In parallel, it addresses two distinct but related observations about neurodegenerative disease: clinico-anatomical convergence and phenotypic heterogeneity. It then examines disease onset and models of progression in more detail, based on available neuroimaging evidence. Finally, it touches on the most important frontiers in the field of network-based neurodegeneration.
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López-Calvo, Ignacio, ed. A History of Chilean Literature. Cambridge University Press, 2021. http://dx.doi.org/10.1017/9781108766616.

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This book covers the full range and diversity of Chilean literature from the times of the Spanish conquest to the present. By emphasizing transnational, hemispheric, and global approaches to Chilean literature, it reflects the relevance of themes such as neoliberalism, migration and exile, as well as subfields like ethnic studies, and gender and sexuality studies. It showcases the diversity of Chilean literature throughout all periods, regions, ethnocultural groups and social classes, all the while foregrounding its regional variations. Unlike previous literary histories, it maps a rich heterogeneity by including works by Chileans of indigenous, African, Jewish, Arab, Asian, and Croatian ancestries, as well as studies of literature by LGTBQ authors and Chilean Americans. Ambitious and authoritative, this book is essential reading for scholars of Chilean Literature, Latin American Literature, the Global South, and World Literature.
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Operskalski, Joachim T., and Aron K. Barbey. Cognitive Neuroscience of Causal Reasoning. Edited by Michael R. Waldmann. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199399550.013.16.

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The era of functional neuroimaging promised to shed light on dark corners of the brain’s inner workings, breathing new life into subfields of psychology beset by controversy. Although revelations from neuroscience provide the foundation for current views on many aspects of human cognition, there continue to be areas of study in which a mismatch between the questions asked by psychologists and neuroscientists renders the implications of neuroscience research unclear. Causal reasoning is one such topic, for which decades of cognitive neuroscience findings have revealed a heterogeneity of participating brain regions and networks across different experimental paradigms. This chapter discusses (i) three cognitive and computational models of causal reasoning (mental models, causal models, and force composition theory), (ii) experimental findings on causal judgment and reasoning using cognitive neuroscience methods, and (iii) the need for a multidisciplinary approach to understanding the nature and mechanisms of causal reasoning.
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9

Carpentier, Chloé, Luis Royuela, Linda Montanari, and Philip Davis. The Global Epidemiology of Drug Use in Prison. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199374847.003.0002.

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This chapter provides an overview of drug use in prison. It is centered on illicit drug use in Europe, where the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) has been collecting aggregated data from various sources for 15 years. It also reviews, based on published literature, data from the four other global regions. A total of 59 studies from 31 countries in the five world regions were included for analysis. Results show that the prevalence of drug use varies greatly between studies. Lifetime prevalence of any illicit drug use in prison ranges between 2% to 76% worldwide with, in most cases, cannabis being the most frequently reported substance. More recent (past-month) illicit drug use is reported by <1% to 65% of inmates, while <1% to 39% report injecting illicit drugs during their stay in prison. Alcohol use in prison is reported in a few studies only, varying between 2% to 77% while the prevalence of current tobacco smoking ranges between 4% to 90%. In general, available data are scarce and patchy, especially outside Europe, with large variations in methodology relating to sampling strategy and measurement. This heterogeneity hampers comparison and may, in part, account for the wide range of prevalence estimates. Comparable methods and measures of drug use and its consequences in prison populations are needed to facilitate international comparisons and provide the sound information needed for development and implementation of drug interventions in various prison settings across the globe.
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Frosio, Giancarlo, ed. Oxford Handbook of Online Intermediary Liability. Oxford University Press, 2020. http://dx.doi.org/10.1093/oxfordhb/9780198837138.001.0001.

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The theoretical—and market—background against which the intermediary liability debate developed has changed considerably since the first appearance of online intermediaries almost two decades ago. These changes have been reflected—or will soon most likely be reflected—in changing policy approaches. The role of Online Service Providers (OSPs) is unprecedented for their capacity to influence the informational environment and users’ interactions within it. The ethical implications of OSPs’ role in contemporary information societies are raising unprecedented social challenges. The decisions made by these platforms increasingly shape contemporary life. Therefore, whether and when access providers and communications platforms such as Google, Twitter, and Facebook are liable for their users’ online activities is a key factor that affects innovation and fundamental rights. There are emerging legal, policy, and ethical issues facing online intermediaries that have so far received various inconsistent answers even within the same jurisdiction. To better understand the heterogeneity of the international online intermediary liability regime, The Oxford Handbook of Online Intermediary Liability is designed to provide a comprehensive, authoritative, and ‘state-of-the-art’ discussion of this topic. This book will review fundamental legal issues in online intermediary liability, while also describing advances in intermediary liability theory and identifying recent policy trends.
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Частини книг з теми "Heterogeneity of regimes"

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Bhimji, Fazila. "Heterogeneity and the Dynamics of Tent Protests and Squatting: The Refugee Movement at Oranienplatz." In Border Regimes, Racialisation Processes and Resistance in Germany, 49–63. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-49320-2_3.

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2

Krebs, Stefan, and Heike Weber. "Rethinking the History of Repair:." In The Persistence of Technology, 27–48. Bielefeld, Germany: transcript Verlag, 2021. http://dx.doi.org/10.14361/9783839447413-003.

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Stefan Krebs and Heike Weber historicise the concept of "repairing things" with a view to broadening and redefining the emphasis of current debates on repair as a "new social movement" and the emergence of a "repair society". These current discourses often lack a sense of the long history of repairing things which saw ups and downs in cultures of repair and self-repair. The chapter charts out the heterogeneity and interrelatedness of the actors involved in repair over time. It draws on examples from Western Europe and North America to highlight some important moments in the history of repair, the intrinsic links between professional and DIY repair practices, discourses on the "lifespan" of things, and changing disposal regimes.
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3

Lindhé, Magnus, and Karl Henrik Johansson. "A Formation Control Algorithm using Voronoi Regions." In Taming Heterogeneity and Complexity of Embedded Control, 419–34. Newport Beach, CA USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9780470612217.ch24.

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4

Popov, Valentin L. "Adhesion Hysteresis Due to Chemical Heterogeneity." In Springer Tracts in Mechanical Engineering, 473–83. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60124-9_20.

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AbstractAccording the JKR theory of adhesivecontact, changes of the contact configuration after formation of the adhesive neck and before detaching are completely reversible. This means, that after formation of the initial contact, the force-distance dependencies should coincide, independently of the direction of the process (indentation or pull-off). In the majority of real systems, this invariance is not observed. The reasons for this may be either plastic deformation in the contacting bodies or surface roughness. One further mechanism of irreversibility (and corresponding energy dissipation) may be chemical heterogeneity of the contact interface leading to the spatial dependence of the specific work of adhesion. In the present paper, this “chemical” mechanism is analyzed on a simple example of an axisymmetric contact (with axisymmetric heterogeneity). It is shown that in the asymptotic case of a “microscopic heterogeneity”, the system follows, during both indentation and pull-off, JKR curves, however, corresponding to different specific surface energies. After the turning point of the movement, the contact area first does not change and the transition from one JKR curve to the other occurs via a linear dependency of the force on indentation depth. The macroscopic behavior is not sensitive to the absolute and relative widths of the regions with different surface energy but depends mainly on the values of the specific surface energy.
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5

Graaff, Thomas de, Daniel Arribas-Bel, and Ceren Ozgen. "Demographic Aging and Employment Dynamics in German Regions: Modeling Regional Heterogeneity." In Advances in Spatial Science, 211–31. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-68563-2_11.

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6

Shafer, Sarah L., Patrick J. Bartlein, and Cathy Whitlock. "Understanding the Spatial Heterogeneity of Global Environmental Change in Mountain Regions." In Advances in Global Change Research, 21–30. Dordrecht: Springer Netherlands, 2005. http://dx.doi.org/10.1007/1-4020-3508-x_3.

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7

Levin, Edward D., Brandon J. Hall, and Amir H. Rezvani. "Heterogeneity Across Brain Regions and Neurotransmitter Interactions with Nicotinic Effects on Memory Function." In The Neurobiology and Genetics of Nicotine and Tobacco, 87–101. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-13665-3_4.

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8

Wei, Jun. "Sustainable Performance of Rural Banking: A Heterogeneity Study in the Coastal Regions of China." In IEIS 2021, 16–23. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-8660-3_3.

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9

Vermersch, P., B. Frigard, A. Wattez, and A. Delacourte. "Distribution of Tau-PHF in Brodmann Areas Reveals a Heterogeneity of the Degenerating Process in Rostro-Caudal Regions and as a Function of Age." In Research and Perspectives in Alzheimer’s Disease, 156–67. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-46776-9_16.

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Doan, Petra L., and Ozlem Atalay. "After the Life of LGBTQ Spaces: Learning from Atlanta and Istanbul." In The Life and Afterlife of Gay Neighborhoods, 261–85. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-66073-4_12.

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AbstractMany gay villages (or “gayborhoods”) arose in the wake of the gay liberation movement attracted a good deal of academic research within the last 40 years. Unfortunately, this hyper focus on certain spaces often populated by white gay men has frequently eclipsed research on other types of LGBTQ areas as well as other geographies beyond the global north. This chapter aims to address this gap, taking an ordinary cities perspective (Robinson, 2006) and asking how we can develop models that are conceptually useful for understanding the life of a more diverse array of LGBTQ spaces across the globe. To answer this question we avoid linear models of change by developing a new model based on a conceptual framework derived from physics: centripetal and centrifugal forces. The advantage of this model is its explicit recognition of the ways that social, economic, and political forces and their manifestations influence queer spaces. We use two cases from relatively under-studied regions; Atlanta and Istanbul to illustrate the utility of this framework. The “in-betweenness” of these cities, linking south and north as well as west and east, makes them a haven for queers and others fleeing the conservative surroundings in the search for more attractive and welcoming places for marginalized LGBTQ individuals. This chapter draws on the authors’ lived experiences, prior research, and additional interviews to conduct a relational reading of queer spaces with emphasis on the ways that LGBTQ people circulate and congregate in a wider range of urban areas. This comparative strategy and relational reading of queer spaces expands the narrow focus from normalized narratives of gayborhoods to a broader “analysis of the heterogeneity and multiplicity of metropolitan modernities” (Roy 2009, p. 821) of queer spaces.
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Тези доповідей конференцій з теми "Heterogeneity of regimes"

1

L'Heureux, Elizabeth. "Scattering regimes and the influence of heterogeneity on the seismic detection of mineral exploration targets." In SEG Technical Program Expanded Abstracts 2006. Society of Exploration Geophysicists, 2006. http://dx.doi.org/10.1190/1.2372477.

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2

Bhate, D., D. Chan, G. Subbarayan, T. C. Chiu, V. Gupta, and D. Edwards. "Constitutive Behavior of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu Alloys at Creep and Low Strain Rate Regimes." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-44151.

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Constitutive models for SnAgCu solder alloys are of great interest at the present. Commonly, constitutive models that have been successfully used in the past for Sn-Pb solders are used to describe the behavior of SnAgCu solder alloys. Two issues in the modeling of lead-free solders demand careful attention: (i) Lead-free solders show significantly different creep strain evolution with time, stress and temperature, and the assumption of evolution to steady state creep nearly instantaneously may not be valid in SnAgCu alloys and (ii) Models derived from bulk sample test data may not be reliable when predicting deformation behavior at the solder interconnection level for lead-free solders due to the differences in the inherent microstructures at these different scales. In addition, the building of valid constitutive models from test data derived from tests on solder joints must deconvolute the effects of joint geometry and its influence on stress heterogeneity. Such issues have often received insufficient attention in prior constitutive modeling efforts. In this study all of the above issues are addressed in developing constitutive models of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys, which represent the extremes of Ag composition that have been mooted at the present time. The results of monotonic testing are reported for strain rates ranging from 4.02E-6 to 2.40E-3 s−1. The creep behavior at stress levels ranging from 7.8 to 52 MPa are also described. Both types of tests were performed at temperatures of 25°C, 75°C and 125°C. The popular Anand model and the classical time-hardening creep model are fit to the data and the experimentally obtained model parameters are reported. The test data are compared against other reported data in the literature and conclusions are drawn on the plausible sources of error in the data reported in the prior literature.
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3

Ogbeiwi, Precious, and Karl Stephen. "Modelling and Upscaling Unstable Miscible Displacement Processes: Characterisation of Physical Instabilities." In SPE Europec featured at 82nd EAGE Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205117-ms.

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Abstract The compositional simulations are required to model CO2 flooding are computationally expensive particularly for fine-gridded models that have high resolutions, and many components. Upscaling procedures can be used in the subsurface flow models to reduce the high computation requirements of the fine grid simulations and accurately model miscible CO2 flooding. However, the effects of physical instabilities are often not well represented and captured by the upscaling procedures. This paper presents an approach for upscaling of miscible displacements is presented which adequately represents physical instabilities such as viscous and heterogeneity induced fingering on coarser grids using pseudoisation techniques. The approach was applied to compositional numerical simulations of two-dimensional reservoir models with a focus on CO2 injection. Our approach is based on the pseudoisation of relative permeability and the application of transport coefficients to upscale viscous fingering and heterogeneity-induced channelling in a multi-contact miscible CO2 injection. Pseudo-relative permeability curves were computed using a pseudoisation technique and applied in combination with transport coefficients to upscale the behaviour of fine-scale miscible CO2 flood simulations to coarser scales. The accuracy of the results of the pseudoisation procedures were assessed by applying statistical analysis to compare them to the results of the fine grid simulations. It is observed from the results that the coarse models provide accurate predictions of the miscible displacement process and that the fingering regimes are adequately captured in the coarse models. The study presents a framework that can be employed to represent the dynamics of physical instabilities associated with miscible CO2 displacements in upscaled coarser grid reservoir models.
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4

Ibrahim, Ahmed Farid, Mazher Ibrahim, Matt Sinkey, Thomas Johnston, and Wes Johnson. "Unique Fall Off Signatures for Stage Fracture Characterization, Actual Field Cases." In SPE Western Regional Meeting. SPE, 2021. http://dx.doi.org/10.2118/200887-ms.

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Abstract Multistage hydraulic fracturing is the common stimulation technique for shale formations. The treatment design, formation in-situ stress, and reservoir heterogeneity govern the fracture network propagation. Different techniques have been used to evaluate the fracture geometry and the completion efficiency including Chemical Tracers, Microseismic, Fiber Optics, and Production Logs. Most of these methods are post-fracture as well as time and cost intensive processes. The current study presents the use of fall-off data during and after stage fracturing to characterize producing surface area, permeability, and fracture conductivity. Shut-in data (15-30 minutes) was collected after each stage was completed. The fall-off data was processed first to remove the noise and water hammer effects. Log-Log derivative diagnostic plots were used to define the flow regime and the data were then matched with an analytical model to calculate producing surface area, permeability, and fracture conductivity. Diagnostic plots showed a unique signature of flow regimes. A long period of a spherical flow regime with negative half-slope was observed as an indication for limited entry flow either vertically or horizontally. A positive half-slope derivative represents a linear flow regime in an infinitely conductive tensile fracture. The quarter-slope derivative was observed in a bilinear flow regime that represents a finite conductivity fracture system. An extended radial flow regime was observed with zero slope derivative which represents a highly shear fractured network around the wellbore. For a long fall-off period, formation recharge may appear with a slope between unit and 1.5 slopes derivative, especially in over-pressured dry gas reservoirs. Analyzing fall-off data after stages are completed provides a free and real-time investigation method to estimate the fracture geometry and a measure of completion efficiency. Knowing the stage properties allows the reservoir engineer to build a simulation model to forecast the well performance and improve the well spacing.
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5

Ren, Bo, Jerry Jensen, Larry Lake, Ian Duncan, and Frank Male. "Analysis of Vertical Permeability and Its Influence on CO2 EOR and Storage in a Carbonate Reservoir." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205995-ms.

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Abstract The objective of this study is to improve understanding of the geostatistics of vertical (bed-normal) permeability (kz) and its influence on reservoir performance during CO2 enhanced oil recovery (EOR) and storage. kz is scrutinized far less often than horizontal permeability (kx, ky) in most geological and reservoir modeling. However, our work indicates that it is equally important to understand kz characteristics to better evaluate their influence on CO2 EOR and storage performance prediction. We conducted this study on about 9,000 whole-core triaxial permeability (kx, ky, kz) measurements from 42 wells in a San Andres carbonate reservoir. We analyzed kz data, including heterogeneity, correlation, and sample sufficiency measures. We analyzed wells with the largest and smallest fractions of points with kz &gt; kmax = max(kx, ky), to explore geological factors that coincided with large kz. We quantified these geological effects through conditional probabilities on potential permeability barriers (e.g., stylolites). Every well had at least some whole-cores where kz &gt; kmax. This is a statistically justifiable result; only where Prob(kz &gt; kmax) is statistically different from 1/3 are core samples non-isotropic. In conventional core data interpretation, however, modelers usually assume kz is less than kmax. For the well with the smallest fraction (11%) of cores where kz &gt; kmax, the cumulative distribution functions differ and coincides with the presence of stylolites. We found that kz is about twice as variable as kx in many wells. This makes kz more difficult to interpret because it was (and usually is) heavily undersampled. To understand the influence of kz heterogeneity on CO2 flow, we built a series of flow simulation models that captured these geostatistical characteristics of permeability, while considering kz realizations, flow regimes (e.g., buoyant flow), CO2 injection strategies, and reservoir heterogeneity. CO2 flow simulations showed that, for viscous flow, assuming variable kx similar to the reservoir along with a constant kz/kx = 0.1 yields a close (within 0.5%) cumulative oil production to the simulation case with both kx and kz as uncorrelated variables. However, for buoyant flow, oil production differs by 10% (at 2.0 hydrocarbon pore volume HCPV of CO2 injected) between the two cases. Such flows could occur for small CO2 injection rates and long injection times, in interwell regions, and/or with vertically permeable conduits. Our geostatistical characterization demonstrates the controls on kz in a carbonate reservoir and how to improve conventional interpretation practices. This study can help CO2 EOR and storage operators refine injection development programs, particularly for reservoirs where buoyant flow exists. More broadly, the findings potentially apply to other similar subsurface buoyancy-driven flow displacements, including hydrogen storage, geothermal production, and aquifer CO2 sequestration.
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6

Sirat, Manhal, Mujahed Ahmed, and Xing Zhang. "Predicting Hydraulic Fracturing in a Carbonate Gas Reservoir in Abu Dhabi Using 1D Mechanical Earth Model: Uncertainty and Constraints." In SPE Middle East Unconventional Resources Conference and Exhibition. SPE, 2015. http://dx.doi.org/10.2118/spe-172942-ms.

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Abstract In-situ stress state plays an important role in controlling fracture growth and containment in hydraulic fracturing managements. It is evident that the mechanical properties, existing stress regime and the natural fracture network of its reservoir rocks and the surrounding formations mainly control the geometry, size and containments of produced hydraulic fractures. Furthermore, the three principal in situ stresses' axes swap directions and magnitudes at different depths giving rise to identifying different mechanical bedrocks with corresponding stress regimes at different depths. Hence predicting the hydro-fractures can be theoretically achieved once all the above data are available. This is particularly difficult in unconventional and tight carbonate reservoirs, where heterogeneity and highly stress variation, in terms of magnitude and orientation, are expected. To optimize the field development plan (FDP) of a tight carbonate gas reservoir in Abu Dhabi, 1D Mechanical Earth Models (MEMs), involving generating the three principal in-situ stresses' profiles and mechanical property characterization with depth, have been constructed for four vertical wells. The results reveal the swap of stress magnitudes at different mechanical layers, which controls the dimension and orientation of the produced hydro-fractures. Predicted containment of the Hydro-fractures within the specific zones is likely with inevitable high uncertainty when the stress contrast between Sv, SHmax with Shmin respectively as well as Young's modulus and Poisson's Ratio variations cannot be estimated accurately. The uncertainty associated with this analysis is mainly related to the lacking of the calibration of the stress profiles of the 1D MEMs with minifrac and/or XLOT data, and both mechanical and elastic properties with rock mechanic testing results. This study investigates the uncertainty in predicting hydraulic fracture containment due to lacking such calibration, which highlights that a complete suite of data, including calibration of 1D MEMs, is crucial in hydraulic fracture treatment.
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7

Heidari, Mohammad, Christopher Istchenko, William Bailey, and Terry Stone. "Use of Horizontal Drift-Flux Models For Simulating Wellbore Flow in SAGD Operations." In SPE Reservoir Simulation Conference. SPE, 2021. http://dx.doi.org/10.2118/203955-ms.

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Abstract The paper examines new horizontal drift-flux correlations for their ability to accurately model phase flow rates and pressure drops in horizontal and undulating wells that are part of a Steam-Assisted Gravity Drainage (SAGD) field operation. Pressure profiles within each well correlate to the overall performance of the pair. SAGD is a low-pressure process that is sensitive to reservoir heterogeneity and other factors, hence accurate simulation of in situ wellbore pressures is critical for both mitigating uneven steam chamber evolution and optimizing wellbore design and operation. Recently published horizontal drift-flux correlations have been implemented in a commercial thermal reservoir simulator with a multi-segment well model. Valid for horizontally drilled wells with undulations, they complement previously reported drift-flux models developed for vertical and inclined wells down to approximately 5 degrees from horizontal. The formulation of these correlations has a high degree of nonlinearity. These models are tested in simulations of SAGD field operations. First, an overview of drift-flux models is discussed. This differentiates those based on vertical flow with gravity segregation to those that model horizontal flow with stratified and slug flow regimes. Second, the most recent and significant drift-flux correlation by Bailey et al. (2018, and hereafter referred to as Bailey-Tang-Stone) was robustly designed to be used in the well model of a reservoir simulator, can handle all inclination angles and was optimized to experimental data from the largest available databases to date. This and earlier drift-flux models are reviewed as to their strengths and weaknesses. Third, governing equations and implementation details are given of the Bailey-Tang-Stone model. Fourth, six case studies are presented that illustrate homogeneous and drift-flux flow model differences for various well scenarios.
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8

Moroshkina, Marina V. "Heterogeneity Of Russian Regions Production And Investment Potential." In Conference on Land Economy and Rural Studies Essentials. European Publisher, 2021. http://dx.doi.org/10.15405/epsbs.2021.07.69.

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9

Amiri, E. A., and J. R. Craig. "Effect of Soil Thermal Heterogeneity on Permafrost Evolution." In 18th International Conference on Cold Regions Engineering and 8th Canadian Permafrost Conference. Reston, VA: American Society of Civil Engineers, 2019. http://dx.doi.org/10.1061/9780784482599.057.

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10

Fan, Qingduan, and Zengrong Liu. "Phase Synchronization Based on Regions Heterogeneity in Suprachiasmatic Nucleus." In 2015 International Industrial Informatics and Computer Engineering Conference. Paris, France: Atlantis Press, 2015. http://dx.doi.org/10.2991/iiicec-15.2015.160.

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Звіти організацій з теми "Heterogeneity of regimes"

1

Zhang, Renduo, and David Russo. Scale-dependency and spatial variability of soil hydraulic properties. United States Department of Agriculture, November 2004. http://dx.doi.org/10.32747/2004.7587220.bard.

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Water resources assessment and protection requires quantitative descriptions of field-scale water flow and contaminant transport through the subsurface, which, in turn, require reliable information about soil hydraulic properties. However, much is still unknown concerning hydraulic properties and flow behavior in heterogeneous soils. Especially, relationships of hydraulic properties changing with measured scales are poorly understood. Soil hydraulic properties are usually measured at a small scale and used for quantifying flow and transport in large scales, which causes misleading results. Therefore, determination of scale-dependent and spatial variability of soil hydraulic properties provides the essential information for quantifying water flow and chemical transport through the subsurface, which are the key processes for detection of potential agricultural/industrial contaminants, reduction of agricultural chemical movement, improvement of soil and water quality, and increase of agricultural productivity. The original research objectives of this project were: 1. to measure soil hydraulic properties at different locations and different scales at large fields; 2. to develop scale-dependent relationships of soil hydraulic properties; and 3. to determine spatial variability and heterogeneity of soil hydraulic properties as a function of measurement scales. The US investigators conducted field and lab experiments to measure soil hydraulic properties at different locations and different scales. Based on the field and lab experiments, a well-structured database of soil physical and hydraulic properties was developed. The database was used to study scale-dependency, spatial variability, and heterogeneity of soil hydraulic properties. An improved method was developed for calculating hydraulic properties based on infiltration data from the disc infiltrometer. Compared with the other methods, the proposed method provided more accurate and stable estimations of the hydraulic conductivity and macroscopic capillary length, using infiltration data collected atshort experiment periods. We also developed scale-dependent relationships of soil hydraulic properties using the fractal and geostatistical characterization. The research effort of the Israeli research team concentrates on tasks along the second objective. The main accomplishment of this effort is that we succeed to derive first-order, upscaled (block effective) conductivity tensor, K'ᵢⱼ, and time-dependent dispersion tensor, D'ᵢⱼ, i,j=1,2,3, for steady-state flow in three-dimensional, partially saturated, heterogeneous formations, for length-scales comparable with those of the formation heterogeneity. Numerical simulations designed to test the applicability of the upscaling methodology to more general situations involving complex, transient flow regimes originating from periodic rain/irrigation events and water uptake by plant roots suggested that even in this complicated case, the upscaling methodology essentially compensated for the loss of sub-grid-scale variations of the velocity field caused by coarse discretization of the flow domain. These results have significant implications with respect to the development of field-scale solute transport models capable of simulating complex real-world scenarios in the subsurface, and, in turn, are essential for the assessment of the threat posed by contamination from agricultural and/or industrial sources.
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2

Spitzer, Sonja, Vanessa di Lego, Angela Greulich, and Raya Muttarak. A demographic perspective on human wellbeing: Concepts, measurement and population heterogeneity. Verlag der Österreichischen Akademie der Wissenschaften, September 2021. http://dx.doi.org/10.1553/populationyearbook2021.int01.

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This introduction to the 2021 special issue of the Vienna Yearbook of Population Research explores demographic perspectives on human wellbeing across time and space. While the idea of relating demographic parameters to wellbeing has been around for a while, a more concrete research agenda on this topic has only recently gained momentum. Reviewing the research presented in this volume, we show how existing theoretical concepts and methodological tools in demography can be used to make substantial advances in the study of wellbeing. We also touch upon the many challenges researchers face in defining and measuring wellbeing, with the most important debate being about whether the focus should be on objective or subjective measures. The studies discussed here define wellbeing as health and mortality; as income, education or other resources; as happiness or life satisfaction; or as a combination thereof. They cover wellbeing in historical and contemporary populations in high- and low-income countries, and also point out important barriers to research on wellbeing, including the lack of good quality data in many regions. Finally, we highlight the value of considering population heterogeneities when studying wellbeing in order to identify population subgroups who are likely to fall behind, which can have important policy implications.
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3

Reiter, Claudia, and Sonja Spitzer. Well-being in Europe: decompositions by country and gender for the population aged 50+. Verlag der Österreichischen Akademie der Wissenschaften, March 2021. http://dx.doi.org/10.1553/populationyearbook2021.res4.1.

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The well-being of older Europeans is of increasing importance given the substantialageing of the population. This paper comprehensively analyses well-being forthe population aged 50+ in 26 European countries, using the newly proposedindicator “Years of Good Life” (YoGL), which measures the remaining yearsof life that an individual can expect to live in a “good” state. The indicatorenables the decomposition of well-being into various dimensions, thereby revealingimportant heterogeneities between regions and genders. Results show that numbersof YoGL at age 50 vary considerably between European countries. They are highestin Northern and Western European countries and lowest in Central and EasternEuropean countries, where many “good” years are lost due to low life satisfaction.Interestingly, the high life expectancy levels in Southern Europe do not translate intohigher numbers of YoGL, mainly due to the low levels of physical and cognitivehealth in this region. While women and men can expect to have similar numbersof YoGL, women are likely to spend a smaller proportion of their longer remaininglifetime in a good state. These results demonstrate the importance of using wellbeingindicators that consider population heterogeneity when measuring humanwell-being, especially for older populations.
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Buathong, Thananon, Anna Dimitrova, Paolo Miguel M. Vicerra, and Montakarn Chimmamee. Years of Good Life: An illustration of a new well-being indicator using data for Thailand. Verlag der Österreichischen Akademie der Wissenschaften, August 2021. http://dx.doi.org/10.1553/populationyearbook2021.dat.1.

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While Thailand has achieved high levels of economic growth in recent decades, poverty at the local level has been increasing. Indicators of human development at the national level often mask the differences in well-being across communities. When responding to the need for sustainable development research, the heterogeneity of a population should be emphasised to ensure that no one is left behind. The Years of Good Life (YoGL) is a well-being indicator that demonstrates the similarities and differences between subpopulations in a given sociocultural context over time. The data used in this analysis were collected from Chiang Rai and Kalasin, which are provinces located in regions of Thailand with high poverty rates. Our main results indicate that the remaining years of good life (free from physical and cognitive limitations, out of poverty and satisfied with life) at age 20 among the sample population were 26 years for women and 28 years for men. The results varied depending on the indicators applied in each dimension of YoGL. Our analysis of the YoGL constituents indicated that cognitive functioning was the dimension that decreased the years of good life the most in the main specification. This study demonstrates the applicability of the YoGL methodology in investigating the wellbeing of subpopulations.
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5

Applebaum, Shalom W., Lawrence I. Gilbert, and Daniel Segal. Biochemical and Molecular Analysis of Juvenile Hormone Synthesis and its Regulation in the Mediterranean Fruit Fly (Ceratitis capitata). United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7570564.bard.

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Original Objectives and revisions: (1) "To determine the biosynthetic pathway of JHB3 in the adult C. capitata CA in order to establish parameters for the future choice and synthesis of suitable inhibitors". Modified: to determine the pattern of FR-7 biosynthesis during normal reproductive maturation, and identify enzymes potentially involved in its synthesis. (2) "To correlate allatal epoxidase activity to the biosynthesis of JHB3 at different stages of reproductive maturation/vitellogenesis and evaluate the hypothesis that a specific JH-epoxidase may be rate limiting". Modified: to study the effects of epoxidase inhibitors on the pattern of allatal JH biosynthesis in vitro and on female reproduction in vive. (3) "To probe and clone the gene homologous to ap from C. capitata, determine its exon-intron organization, sequence it and demonstrate its spatial and temporal expression in larvae, pupae and adults." The "Medfly" (Ceratitis capitata) is a serious polyphagous fruit pest, widely distributed in subtropical regions. Damage is caused by oviposition and subsequent development of larvae. JH's are dominant gonadotropic factors in insects. In the higher Diptera, to which the Medfly belongs, JHB3 is a major homolog. It comprises 95% of the total JH produced in vitro in D. melanogaster, with JH-III found as a minor component. The biosynthesis of both JH-III and JHB3 is dependent on epoxidation of double bonds in the JH molecule. The specificity of such epoxidases is unknown. The male accessory gland D. melanogaster produces a Sex Peptide, transferred to the female during copulation. SP reduces female receptivity while activating specific JH biosynthesis in vitro and inducing oviposition in vive. It also reduces pheromone production and activates CA of the moth Helicoverpa armigera. In a previous study, mutants of the apterous (ap) gene of D. melanogaster were analyzed. This gene induces previteilogenic arrest which can be rescued by external application of JH. Considerable progress has been made in recombinant DNA technology of the Medfly. When fully operative, it might be possible to effectively transfer D. melanogaster endocrine gene-lesions into the Medfly as a strategy for their genetic control. A marked heterogeneity in the pattern of JH homologs produced by Medfly CA was observed. Contrary to the anticipated biosynthesis of JHB;, significant amounts of an unknown JH-like compound, of unknown structure and provisionally termed FR-7, were produced, in addition to significant amounts of JH-III and JHB3. Inhibitors of monooxygenases, devised for their effects on ecdysteroid biosynthesis, affect Medfly JH biosynthesis but do not reduce egg deposition. FR-7 was isolated from incubation media of Medfly CA and examined by various MS procedures, but its structure is not yet resolved. MS analysis is being done in collaboration with Professor R.R.W. Rickards of the Australian National University in Canberra, Australia. A homologue of the ap gene of D. melanogaster exists in the Medfly. LIM domains and the homeo-domain, important for the function of the D. melanogaster ap gene, are conserved here too. Attempts to clone the complete gene were unsuccessful. Due to the complexity of JH homologs, presence of related FR-7 in the biosynthetic products of Medfly CA and lack of reduction in eggs deposited in the presence of monooxygenase inhibitors, inhibition of epoxidases is not a feasible alternative to control Medfly reproduction, and raises questions which cannot be resolved within the current dogma of hormonal control of reproduction in Diptera. The Medfly ap gene has similar domains to the D. melanogaster ap gene. Although mutant ap genes are involved in JH deficiency, ap is a questionable candidate for an endocrine lesion, especially since the D. melanogoster gene functions is a transcription factor.
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