275 research outputs found
Strain-controlled band engineering and self-doping in ultrathin LaNiO films
We report on a systematic study of the temperature-dependent Hall coefficient
and thermoelectric power in ultra-thin metallic LaNiO films that reveal a
strain-induced, self-doping carrier transition that is inaccessible in the
bulk. As the film strain varies from compressive to tensile at fixed
composition and stoichiometry, the transport coefficients evolve in a manner
strikingly similar to those of bulk hole-doped superconducting cuprates with
varying doping level. Density functional calculations reveal that the
strain-induced changes in the transport properties are due to self-doping in
the low-energy electronic band structure. The results imply that thin-film
epitaxy can serve as a new means to achieve hole-doping in other (negative)
charge-transfer gap transition metal oxides without resorting to chemical
substitution
Consumption responses to a large shock to financial wealth: evidence from Italy
We estimate marginal propensities to consume from wealth shocks for Italian households early in the Great Recession. Large asset-price shocks in 2007-2008 underpin instrumental variables. A euro fall in risky financial wealth resulted in cuts in annual total (non-durable) consumption of 8.5-9 (5.5-5.7) cents. We find small effects on food spending. Counterfactuals indicate financial-wealth effects were relatively important for consumption falls in Italy in 2007/08. The estimated effects are consistent with a simulated lifecycle model that captures the wealth shock. Also consistent with the model are findings of stronger wealth effects for agents who were pessimistic about stock returns
Electronic properties of bulk and thin film SrRuO: a search for the metal-insulator transition
We calculate the properties of the 4 ferromagnet SrRuO in bulk and
thin film form with the aim of understanding the experimentally observed metal
to insulator transition at reduced thickness. Although the spatial extent of
the 4 orbitals is quite large, many experimental results have suggested that
electron-electron correlations play an important role in determining this
material's electronic structure. In order to investigate the importance of
correlation, we use two approaches which go beyond the conventional local
density approximation to density functional theory (DFT): the local spin
density approximation + Hubbard (LSDA+) and the pseudopotential
self-interaction correction (pseudo-SIC) methods. We find that the details of
the electronic structure predicted with the LSDA do not agree with the
experimental spectroscopic data for bulk and thin film SrRuO. Improvement
is found by including electron-electron correlations, and we suggest that bulk
orthorhombic SrRuO is a {\it weakly strongly-correlated} ferromagnet whose
electronic structure is best described by a 0.6 eV on-site Hubbard term, or
equivalently with corrections for the self-interaction error. We also perform
{\it ab initio} transport calculations that confirm that SrRuO has a
negative spin polarization at the Fermi level, due to the position of the
minority Ru 4 band center. Even with correlations included in our
calculations we are unable to reproduce the experimentally observed
metal-insulator transition, suggesting that the electronic behavior of
SrRuO ultra-thin films might be dominated by extrinsic factors such as
surface disorder and defects.Comment: 15 pages, 12 figures, 3 table
Carrier-mediated magnetoelectricity in complex oxide heterostructures
While tremendous success has been achieved to date in creating both single
phase and composite magnetoelectric materials, the quintessential
electric-field control of magnetism remains elusive. In this work, we
demonstrate a linear magnetoelectric effect which arises from a novel
carrier-mediated mechanism, and is a universal feature of the interface between
a dielectric and a spin-polarized metal. Using first-principles density
functional calculations, we illustrate this effect at the SrRuO/SrTiO
interface and describe its origin. To formally quantify the magnetic response
of such an interface to an applied electric field, we introduce and define the
concept of spin capacitance. In addition to its magnetoelectric and spin
capacitive behavior, the interface displays a spatial coexistence of magnetism
and dielectric polarization suggesting a route to a new type of interfacial
multiferroic
The road to partnerships in practice:Practical wisdom as an alternative to managerialism in NGO partnerships
Worker remittances and the global preconditions of ‘smart development’
With the growing environmental crisis affecting our globe, ideas to weigh economic or social progress by the ‘energy input’ necessary to achieve it are increasingly gaining acceptance. This question is intriguing and is being dealt with by a growing number of studies, focusing on the environmental price of human progress. Even more intriguing, however, is the question of which factors of social organization contribute to a responsible use of the resources of our planet to achieve a given social result (‘smart development’). In this essay, we present the first systematic study on how migration – or rather, more concretely, received worker remittances per GDP – helps the nations of our globe to enjoy social and economic progress at a relatively small environmental price. We look at the effects of migration on the balance sheets of societal accounting, based on the ‘ecological price’ of the combined performance of democracy, economic growth, gender equality, human development, research and development, and social cohesion. Feminism in power, economic freedom, population density, the UNDP education index as well as the receipt of worker remittances all significantly contribute towards a ‘smart overall development’, while high military expenditures and a high world economic openness are a bottleneck for ‘smart overall development’
Towards the Physical Map of the Trypanosoma cruzi Nuclear Genome: Construction of YAC and BAC Libraries of the Reference Clone T. cruzi CL-Brener
Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas diseaseInstituto de Investigaciones en IngenierÃa Genética y BiologÃa MolecularEscola Paulista de MedicinaCBMUniversidade de São PauloUniversidade Federal do Rio de JaneiroIPBUniversidad Central de VenezuelaUSBInstituto Oswaldo CruzCEPHUNIFESP, EPMSciEL
Seeking legitimacy through CSR: Institutional Pressures and Corporate Responses of Multinationals in Sri Lanka
Arguably, the corporate social responsibility (CSR) practices of multinational enterprises (MNEs) are influenced by a wide range of both internal and external factors. Perhaps most critical among the exogenous forces operating on MNEs are those exerted by state and other key institutional actors in host countries. Crucially, academic research conducted to date offers little data about how MNEs use their CSR activities to strategically manage their relationship with those actors in order to gain legitimisation advantages in host countries. This paper addresses that gap by exploring interactions between external institutional pressures and firm-level CSR activities, which take the form of community initiatives, to examine how MNEs develop their legitimacy-seeking policies and practices. In focusing on a developing country, Sri Lanka, this paper provides valuable insights into how MNEs instrumentally utilise community initiatives in a country where relationship-building with governmental and other powerful non-governmental actors can be vitally important for the long-term viability of the business. Drawing on neo-institutional theory and CSR literature, this paper examines and contributes to the embryonic but emerging debate about the instrumental and political implications of CSR. The evidence presented and discussed here reveals the extent to which, and the reasons why, MNEs engage in complex legitimacy-seeking relationships with Sri Lankan institutions
- …