4,121 research outputs found
The Hidden Increase in Wage Inequality: Skill-biased and Ability-biased Technological Change
This study provides strong evidence for an increase in wage inequality induced by skillbiased technological change in the UK manufacturing industry between 1991 and 2006. Using individual level data from the BHPS and industry level data from the OECD, wage regressions are estimated which identify the eff ect of innovative activity on wages – the personal innovation wage premium – for university and less educated workers. Innovative activity is defi ned by R&D expenditure and patent applications to measure innovation input and innovation output, respectively. Using diff erent estimation methods for panel data, such as Fixed eff ects, Random eff ects, Mundlak and Hausman- Taylor models, additionally to pooled OLS allows controlling for both industry-specifi c and individual ability. Using R&D expenditure as a measure for innovative activity additionally provides evidence for ability-biased technological change while patent applications do not support this hypothesis.Wage inequality; skill-biased technological change; ability-biased technological change; United Kingdom
Migration Magnet: The Role of Work Experience in Rural-Urban Wage Diff erentials in Mexico
This study estimates separate selectivity bias corrected wage equations for formal and informal workers in rural and urban Mexico using data from the Mexican Family Life Survey (MxFLS). We control for diff erent potential selection patterns using Probit and Multinominal logit models in the fi rst step in which health, personality traits and family characteristics serve as exclusion restrictions for working per se and working in the formal sector. Oaxaca-Blinder Decompositions show that rural-urban wage inequality in the formal and informal sector is determined by diff erences in observable human capital. In the informal sector, the wage diff erential is mainly explained by diff erences in returns to experience. Furthermore, we analyse rural-to-urban migrants‘ labour market performance. The fi ndings suggest that rural-to-urban migration will continue and the informal sector will further increase.Returns to experience; rural-urban wage diff erentials; informality; internal migration; Mexico
Bodies (that) Matter. The Role of Habit Formation for Identity
This paper will interpret Judith Butler’s theory of performativity and materialization as a theory of identity, and so put it into dialogue with a phenomenological account of habit formation. The goal is to argue that identity is developed already at a bodily level and that this takes place via the processes of habit formation. The constitution of subjectivity, in other words, requires at the most basic level some kind of bodily performativity. What follows intends to draw out the concept of ‘the body’ in Butler’s work, the role of which is surprisingly meagre given her clear favour of language signification in the elaboration of her theory of performativity. Alternatively, this paper will provide a phenomenology of habit formation that re-introduces the body not as thematic materiality, but as lived materiality. The body will therefore be conceived as something which is already skilful and creative, sensitive and vulnerable, and ultimately, as Butler anticipates, responsive to the intertwinement of individual and social aspects of identity formation. In this regard, I will argue for a performative theory of (bodily) habitual identity.
This paper will interpret Judith Butler’s theory of performativity and materialization as a theory of identity, and so put it into dialogue with a phenomenological account of habit formation. The goal is to argue that identity is developed already at a bodily level and that this takes place via the processes of habit formation. The constitution of subjectivity, in other words, requires at the most basic level some kind of bodily performativity. What follows intends to draw out the concept of ‘the body’ in Butler’s work, the role of which is surprisingly meagre given her clear favour of language signification in the elaboration of her theory of performativity. Alternatively, this paper will provide a phenomenology of habit formation that re-introduces the body not as thematic materiality, but as lived materiality. The body will therefore be conceived as something which is already skilful and creative, sensitive and vulnerable, and ultimately, as Butler anticipates, responsive to the intertwinement of individual and social aspects of identity formation. In this regard, I will argue for a performative theory of (bodily) habitual identity.
This paper will interpret Judith Butler’s theory of performativity and materialization as a theory of identity, and so put it into dialogue with a phenomenological account of habit formation. The goal is to argue that identity is developed already at a bodily level and that this takes place via the processes of habit formation. The constitution of subjectivity, in other words, requires at the most basic level some kind of bodily performativity. What follows intends to draw out the concept of ‘the body’ in Butler’s work, the role of which is surprisingly meagre given her clear favour of language signification in the elaboration of her theory of performativity. Alternatively, this paper will provide a phenomenology of habit formation that re-introduces the body not as thematic materiality, but as lived materiality. The body will therefore be conceived as something which is already skilful and creative, sensitive and vulnerable, and ultimately, as Butler anticipates, responsive to the intertwinement of individual an
Comparison of two sampling protocols and four home-range estimators using radio-tracking data from urban badgers Meles meles
Radio-telemetry is often the method of choice for studies of species whose behaviour is difficult to observe directly. However, considerable debate has ensued about the best way of deriving home-range estimates. In recent years, kernel estimators have become the most widely used method, together with the oldest and simplest method, the minimum convex polygon (MCP). More recently, it has been suggested that the local convex hull (LCH) might be more appropriate than kernel methods in cases where an animal’s home range includes a priori inaccessible areas. Yet another method, the Brownian bridge (BB), explicitly uses autocorrelated data to determine movement paths and, ultimately, home ranges or migration routes of animals. Whereas several studies have used simulation techniques to compare these different methods, few have used data from real animals. We used radio-telemetric data from urban badgers Meles meles to compare two sampling protocols (10-minute vs at least 30-minute inter-fix intervals) and four home-range estimators (MCP, fixed kernels (FK), LCH and BB). We used a multi-response permutation procedure and randomisation tests to compare overall patterns of fixes and degree of overlap of home ranges estimated using data from different sampling protocols, and a general linear model to compare the influence of sampling protocols and home-range estimator on the size of habitat patches. The shape of the estimated home ranges was influenced by sampling protocol in some cases. By contrast, the sizes and proportions of different habitats within home ranges were influenced by estimator type but not by sampling protocol. LCH performed consistently better than FK, and is especially appropriate for patchy study areas containing frequent no-go zones. However, we recommend using LCH in combination with other methods to estimate total range size, because LCH tended to produce smaller estimates than any other method. Results relating to BB are preliminary but suggest that this method is unsuitable for species in which range size is small compared to average travel speed.Marie-Curie Intra-European Fellowship (BSSUB - 24007); Defra WSC contract WM0304; Wildlife Biology granted the permit to upload the article to this repositor
A Variational Approach to Particles in Lipid Membranes
A variety of models for the membrane-mediated interaction of particles in
lipid membranes, mostly well-established in theoretical physics, is reviewed
from a mathematical perspective. We provide mathematically consistent
formulations in a variational framework, relate apparently different modelling
approaches in terms of successive approximation, and investigate existence and
uniqueness. Numerical computations illustrate that the new variational
formulations are directly accessible to effective numerical methods
Brief increases in corticosterone affect morphology, stress responses, and telomere length, but not post-fledging movements, in a wild songbird
Organisms are frequently exposed to challenges during development, such as
poor weather and food shortage. Such challenges can initiate the hormonal
stress response, which involves secretion of glucocorticoids. Although the
hormonal stress response helps organisms deal with challenges, long-term
exposure to high levels of glucocorticoids can have morphological, behavioral,
and physiological consequences, especially during development. Glucocorticoids
are also associated with reduced survival and telomere shortening. To
investigate whether brief, acute exposures to glucocorticoids can also produce
these phenotypic effects in free-living birds, we exposed wild tree swallow
(Tachycineta bicolor) nestlings to a brief exogenous dose of cort once per day
for five days and then measured their morphology, baseline and stress-induced
corticosterone levels, and telomere length. We also deployed radio tags on a
subset of nestlings, which allowed us to determine the age at which tagged
nestlings left the nest (fledged) and their pattern of presence and absence at
the natal site during the post-breeding period. Corticosterone-treated
nestlings had lower mass, higher baseline and stress-induced corticosterone,
and reduced telomeres; other metrics of morphology were affected weakly or not
at all. Our treatment resulted in no significant effect on survival to
fledging, fledge age, or age at first departure from the natal site, and we
found no negative effect of corticosterone on inter-annual return rate. These
results show that brief acute corticosterone exposure during development can
have measurable effects on phenotype in free-living tree swallows.
Corticosterone may therefore mediate correlations between rearing environment
and phenotype in developing organisms, even in the absence of prolonged
stressors.Comment: 35 pages, 4 figures, 1 appendi
Bartering with a Nation\u27s Health or Improving Access to Pharmaceuticals? The United States-Australia Free Trade Agreement
Providing access to affordable medicines and rewarding innovation produces a difficult tension in the global economy. Different nations deal with this tension differently, as illustrated by the United States-Australia Free Trade Agreement ( U.S.-Australia FTA ) negotiations. Both nations stood to benefit greatly from reduced or eliminated tariffs. During negotiations, both nations sought to capitalize on the opportunity to alter certain practices that hindered trade. One such practice was Australia\u27s fifty-five-year-old Pharmaceutical Benefits Scheme ( PBS ). The PBS controls prices for most medicines within Australia. Australian consumers are concerned that the U.S.-Australia FTA will adversely affect access to affordable medicines because free trade agreements are generally intended to remove tariffs as well as non-tariff barriers to trade between the parties. This agreement, however, leaves Australia\u27s subsidization program intact. Similar concerns have been raised before, specifically in Canada over the North American Free Trade Agreement ( NAFTA ). Canada, however, is still able to provide access to affordable, yet innovative drugs, even after NAFTA. Australia will be able to do the same well after the U.S.-Australia FTA is fully implemented. The provisions of the U.S.-Australia FITA are minor procedural changes and do not substantively change how the PBS operates
A GLOBAL DATABASE OF DOMESTIC AND INTERNATIONAL TOURIST NUMBERS AT NATIONAL AND SUBNATIONAL LEVEL
We present a new, global data base on tourist destinations. The data base differs from other data bases in that it includes both domestic and international tourists; and it contains data, for the most important destinations, data at national level as well as at lower administrative levels. Missing observations are interpolated using statistical models. The data are freely accessible on the internet.tourism, data
Layer-by-Layer Fabrication of Covalently Crosslinked and Reactive Polymer Multilayers Using Azlactone-Functionalized Copolymers: A Platform for the Design of Functional Biointerfaces
We report a method for modulating the physicochemical properties of surfaces that is based on the reactive layer-by-layer fabrication of covalently crosslinked thin films using azlactone-functionalized copolymers. We demonstrate that copolymers containing different molar ratios of methyl methacrylate (MMA) and 2-vinyl-4,4-dimethylazlactone (VDMA) can be alternately deposited with poly(ethyleneimine) to assemble covalently crosslinked thin films. Characterization using ellipsometry demonstrates that, in general, film growth and thickness decrease as the content of reactive, azlactone functionality in the copolymer used to assemble the film decreases. Reflective infrared spectroscopy experiments demonstrate that films fabricated from MMA:VDMA copolymers contain residual azlactone functionality and that these reactive groups can be exploited to modify film-coated surfaces. Fabricating films from MMA:VDMA copolymers containing different compositions permitted modulation of the density of reactive groups within the films and, thus, the extent to which the films are functionalized by exposure to small molecule amines. For example, functionalization of MMA:VDMA copolymer films with the small molecule D-glucamine resulted in films with water contact angles that varied with the composition of the copolymer used to fabricate the film (e.g., as the azlactone content in the film increased, glucamine-modified films became more hydrophilic). We demonstrate further that treatment of copolymer-containing films with glucamine resulted in changes in the numbers of mammalian cells that grow on the surfaces of the films. Our results suggest the basis of methods that could be used to modulate or tune the density of chemical and biological functionality presented on surfaces of interest in a variety of fundamental and applied contexts
Functionalization of Fibers Using Azlactone-Containing Polymers: Layer-by-Layer Fabrication of Reactive Thin Films on the Surfaces of Hair and Cellulose-Based Materials
We report an approach to the functionalization of fibers and fiber-based materials that is based on the deposition of reactive azlactone-functionalized polymers and the reactive layer-by-layer assembly of azlactone-containing thin films. We demonstrate (i) that the azlactone-functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) can be used to modify the surfaces of a model protein-based fiber (horsehair) and cellulose-based materials (e.g., cotton and paper), and (ii) that fibers functionalized in this manner can be used to support the fabrication of covalently cross-linked and reactive polymer multilayers assembled using PVDMA and poly(ethyleneimine) (PEI). The growth, chemical reactivity, and uniformity of films deposited on these substrates were characterized using fluorescence microscopy, confocal microscopy, and scanning electron microscopy (SEM). In addition to the direct functionalization of fibers, we demonstrate that the residual azlactone functionality in PVDMA-treated or film-coated fibers can be exploited to chemically modify the surface chemistry and physicochemical properties of fiber-based materials postfabrication using amine functionalized molecules. For example, we demonstrate that this approach permits control over the surface properties of paper (e.g., absorption of water) by simple postfabrication treatment of film-coated paper with the hydrophobic amine n-decylamine. The azlactone functionality present in these materials provides a platform for the modification of polymer-treated and film-coated fibers with a broad range of other chemical and biological species (e.g., enzymes, peptides, catalysts, etc.). The results of this investigation thus provide a basis for the functionalization of fibers and fiber-based materials (e.g., textile fabrics or nonwoven mats) of potential utility in a broad range of consumer, industrial, and biomedical contexts
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