770 research outputs found
Non-price Competition, Real Rigidities and Inflation Dynamics
In the last decade, the analytical progress achieved in the New Keynesian literature has been remarkable. Many of the early assumptions have been relaxed, leading to medium-scale macroeconomic models that are now able to capture many features of real-world data. Nevertheless, modern-day New Keynesian models still assume, as did their early counterparts, that firms compete in the market with no tools other than their relative prices. In particular, this literature has so far neglected the consequences of extending competition between firms to the non-price dimension. This paper tries to fill this gap by enriching the canonical New Keynesian framework to include both price and non-price competition. This has important consequences for the analysis of inflation dynamics, modifying in particular the inflation-marginal cost relationship. As a general result, we show that any activity by firms that boosts demand for their products, without directly affecting their prices, dampens the overall degree of real rigidities in price-setting.Non-price competition, inflation dynamics, real rigidity
The last fifteen years of stagnation in Italy: A Business Cycle Accounting Perspective
In this paper, we investigate possible sources of declining economic growth performance in Italy starting around the middle of the ’90s. A long-run data analysis suggests that the poor performance of the Italian economy cannot be ascribed to an unfortunate business cycle contingency. The rest of the euro area countries have shown better performance, and the macroeconomic data show that the Italian economy has not grown as rapidly as these other European economies. We investigate the sources of economic fluctuations in Italy by applying the Business Cycle Accounting procedure introduced by Chari, Kehoe and McGrattan (2007). We analyze the relative importance of efficiency, labor, investment and government wedges for business cycles in Italy over the 1982-2008 period. We find that different wedges have played different roles during the period, but the efficiency wedge is revealed to be the main factor responsible for the stagnation phase beginning around 1995. Our findings also show that the improvement in labor market distortions that occurred in Italy during the ’90s provided an alleviating effect, preventing an even stronger slowdown in per capita output growth.
Advertising, Labor Supply and the Aggregate Economy. A long run Analysis
This paper studies the influence of persuasive advertising in a neoclassical growth model with monopolistically competitive firms. Our findings show that advertising can significantly affect the stationary equilibrium of a model economy in which the labor supply is endogenous. In this case, for empirically plausible calibrations, we find that the equilibrium level of hours worked, GDP, and consumption increase with the amount of resources invested in advertising. These findings are consistent with a new stylized fact provided in this paper: over the past decade, per-capita advertising expenditures have been positively correlated with per-capita output, consumption and hours worked across OECD countries. Because of the connection between advertising and labor supply, we show that our model improves on its neoclassical counterpart in explaining both within-country and cross-country variability of hours worked per capita.Advertising, Labor Wedge, Labor supply, Economic Growth, Hours Worked.
Advertising and Business Cycle Fluctuations
This paper provides new empirical evidence for quarterly U.S. aggregate advertisingexpenditures, showing that advertising has a well defined pattern over the BusinessCycle. To understand this pattern we develop a general equilibrium model wheretargeted advertising increases the marginal utility of the advertised good. Advertisingintensity is endogenously determined by profit maximizing firms. We embed thisassumption into an otherwise standard model of the business cycle withmonopolistic competition. We find that advertising affects the aggregate dynamics ina relevant way, and it exacerbates the welfare costs of fluctuations for the consumer.Finally, we provide estimates of our setup using Bayesian techniques.Advertising, DSGE model, Business Cycle fluctuations, Bayesian
Cleaning up Disaster or Making More - A Look at Avenues of Relief for Those Devastated by the Clean-up Efforts of Hurricane Katrina
FROM ESSENTIALISM TO THE ESSENTIAL: PRAGMATICS AND MEANING OF PUNEÑO SIKURI PERFORMANCE IN LIMA
Cleaning up Disaster or Making More - A Look at Avenues of Relief for Those Devastated by the Clean-up Efforts of Hurricane Katrina
Engineering plasmonic nanomaterials for SERS applications
En conseqüència de les seves extraordinàries propietats, les nanopartícules d'or i plata s'han utilitzat en una varietat d'aplicacions, incloses les relacionades amb surface-enhanced Raman scattering (SERS) spectroscopy. La creixent ocupació d'aquesta tècnica com a eina analítica, va empènyer la investigació al studio de nous substrats SERS. Considerant aquestes dades, la thesis proposada té com a objectiu examinar estratègies per al disseny de nanomaterials nous i expandeix la molecular library de lligands de superfície per funcionalitzar les plataformes plasmòniques amb un enfocament especial a l'aplicació SERS.
Primer, es proposa un mètode per a la formació homogènia d'una capa de plata sobre nuclis d'or amb diferents característiques geomètriques a través d'un procés de cold nanowelding. solució. En particular, la investigació realitzada ha demostrat la forta implicació d'alguns paràmetres experimentals en la generació d'estructures bimetàl·liques d'Au/Ag que conserven la morfologia del substrat d'or original.
Segon, un nou derivat de azobenzè va ser proposat com a quimioreceptor eficaç i de baix cost per a la detecció SERS de tiols de baix pes molecular clínicament rellevants. Més concretament, els agregats de nanopartícules de plata col·loïdalment estables es van equipar amb el mercapte-azobenzè derivat que, en presència de biotíols, mostra importants alteracions espectrals SERS correlacionades quantitativament amb el trencament de l'enllaç diazo intervingut per molècules petites tiolades.
Finalment es va estudiar la producció d'una graded-index (GRIN) lens que es va obtenir mitjançant l'acoblament jeràrquic de nanopartícules d'or en un nucli micromètric de sílice amb l'objectiu d'examinar les propietats exòtiques òptiques relacionades amb la complexa arquitectura i que consisteixen en la capacitat del sistema de concentrar la llum al centre de la microesfera.Debido a sus extraordinarias propiedades, las nanopartículas de oro y plata se han utilizado en una variedad de aplicaciones, incluidas las que estan relacionada con surface-enhanced Raman scattering (SERS) spectroscopy. El creciente empleo de esta técnica como herramienta analítica, empujó la investigación en el studio de nuevos sustratos SERS. Considerando estos datos, la thesis propuesta tiene como objetivo examinar estrategias para el diseño de nanomateriales novedosos y expande la molecular library de ligandos de superficie para funcionalizar las plataformas plasmónicas con un enfoque especial en la aplicación SERS.
Primero, se propone un metodo para la formación homogenea de una capa de plata sobre núcleos de oro con diferentes características geométricas a través de un proceso de cold nanowelding- La nueva estrategia sintetica pretende superar las limitaciones identificadas en las reducciones químicas convencionales de sales metálicas en solución. En particular, la investigación realizada ha demostrado la fuerte implicación de algunos parámetros experimentales en la generación de estructuras bimetálicas de Au/Ag que conservan la morfología del sustrato de oro original.
Segundo, un nuevo derivado de azobenceno fue propuesto como quimiorreceptor eficaz y de bajo coste para la detección SERS de tioles de bajo peso molecular clínicamente relevantes. Más concretamente, los agregados de nanopartículas de plata coloidalmente estables se equiparon con el mercapto-azobenceno derivado que, en presencia de biotioles, muestra importantes alteraciones espectrales SERS correlacionadas cuantitativamente con la rotura del enlace diazo mediada por moléculas pequeñas tioladas.
Finalmente se estudió la producción de una graded-index (GRIN) lens que se obtuvo mediante el ensamblaje jerárquico de nanopartículas de oro en un núcleo micrométrico de sílice con el objetivo de examinar las propiedades exóticas ópticas relacionada con la compleja arquitectura y que consisten en la capacidad del sistema de concentrar la luz en el centro de la microesfera.Due to their exceptional properties, gold and silver nanoparticles have been used in a variety of applications, including those related to surface-enhanced Raman scattering (SERS) spectroscopy. In this regard, the increasing employment of this spectroscopic technique as an ultrasensitive analytical tool in a wide range of application fields, encouraged research in further improvements in the SERS substrates engineering. With these considerations in mind, the proposed dissertation aims to examine approaches for the design of novelty nanomaterials and expands the molecular library surface ligands that can decorate the plasmonic platforms with a special focus on SERS application.
First, the formation of a smooth silver layer onto gold cores with different geometrical features through a cold nanowelding process was proposed as a new synthetical approach that overcomes the issues identified in the conventional chemical reductions of metal salts in solution. In particular, the conducted research has demonstrated the strong implication of some experimental parameters in the generation of bimetallic Au/Ag structures that retain the original gold substrate morphology.
Secondly, a novel azobenzene derivative was synthesized as an efficient low-cost chemoreceptor for the SERS detection of clinically relevant low molecular weight thiols. More concretely, colloidally stable silver nanoparticle clusters were equipped with the obtained mercapto-azobenzene probe that, in the presence of biothiols, displays dramatic SERS spectral alterations quantitatively correlated to the small thiolated molecules-mediated breakage of the diazo bond.
The dissertation finally reports a study conducted on the production of a metallic metamaterial. The resulting hybrid graded-index (GRIN) lens was obtained through the hierarchical assembly of gold nanoparticles onto a micrometric core of silica with the aim to examine the exotic optical properties to concentrate the light at the center of the microsphere deriving from the complex architecture
The role of passive margins in the continental collision dynamics
I margini passivi, formati durante il processo di rifting, sono caratterizzati da una zona tra continente e oceano costituita da litosfera continentale assottigliata a seguito dell’estensione. La dinamica del rifting influenza le dimensioni e la geometria del margine passivo. Inoltre, i margini passivi denominati magma rich sono associati ad una elevata produzione di magma derivante dalla fusione del mantello e alla conseguente messa in posto di rocce mafiche intrusive ed estrusive, mentre questo non avviene nel caso di margini magma poor. Tutte queste differenze fanno sì che la geometria e la reologia dei margini passivi siano molto varie.
In questo progetto ho studiato come i diversi tipi di margini passivi, una volta arrivati alla zona di cerniera, influenzino la dinamica della subduzione e collisione continentale. In particolare, ho studiato la rottura dello slab in profondità e l’accrezione di crosta continentale alla placca sovrascorrente. Questi processi sono influenzati dalle caratteristiche del margine.
Ho quindi sviluppato dei modelli bidimensionali di subduzione modellando diversi tipi di margini passivi, utilizzando un codice di modellazione numerica ad elementi finiti (Citcom), per avere una migliore comprensione del processo di subduzione e di capire ed interpretare la geologia delle zone di collisione continentale.
I risultati mostrano che la presenza di margini passivi ha un impatto importante sul processo di subduzione. Si vede, infatti, che la variazione di profondità del break-off dello slab varia su 300 km, mentre quella del tempo relativo al break-off è di 50 Myr. I modelli che descrivono i margini magma poor, inoltre, sono consistenti con osservazioni geologiche che mostrano che parte del margine viene trasferito sulla placca sovrascorrente. Quelli che modellano i margini magma rich, invece, mostrano che il break-off avviene al di sopra del margine, in linea con le osservazioni che mostrano che è raro osservare margini di questo tipo in natura
The Role of Mindful Disposition in Exploring Teacher Effectiveness in an Arts Integrated School: An Embedded Mixed Method Design
Currently there is high pressure on teachers to demonstrate effectiveness through student outcome scores and observational criteria in classrooms (CO SB 10-191, 2010; Darling-Hammond et al., 2012). What is missing from the teacher effectiveness evaluation process is a voice of the teacher as a professional about their practice. One of the emerging research fields discussing the effects of the pressures on teachers (and students) is mindfulness (Albrecht et al., 2012; Jennings & Greenberg, 2009). This study serves to bring these two fields of research: teacher effectiveness evaluation and mindfulness in education together.
Three research questions guided this embedded mixed methods design study: 1) How do students respond on a standardized measure in a classroom instructed by a teacher with a mindful attention awareness disposition? 2) What forms of instruction are dominant in a classroom taught by a teacher who demonstrates a mindful attention awareness disposition? 3) What is the experience of teaching like for a teacher with a mindful attention awareness disposition? To respond to the questions the qualitative research method of Educational Criticism and Connoisseurship developed by Elliot Eisner (1998) was used. Educational criticism is comprised of four dimensions: description, interpretation, evaluation, and thematics. To also respond to question one a quantitative analysis of a 2x(2) mixed-design ANOVA to explore the differences in secondary student outcome data provided by the district was conducted looking at level of mindfulness of the teacher and scores over time.
The findings suggest that the seven attitudinal factors of mindfulness (Kabat-Zinn, 2005) are operationalized in the classrooms of teachers with high mindful attention awareness disposition. However, the teacher\u27s level of mindfulness had no significant effect on standardized student outcome data and there was no statistically significant interaction between teacher disposition and time. This suggests that the current model of standardization in measuring teacher effectiveness is not completely informing what we want to understand as in relationship to effective teaching in the classroom.
Mindfulness has been studied to show positive effects with teachers and students (Brown & Ryan, 2003; Harris et al., 2013; Weinstein, Brown & Ryan, 2009). This study introduces language to describe what mindful disposition looks like when operationalized in the classroom. This language can now be used in future research to support studies that look at the impact of mindfulness programs as well as utilized as reflective language for practitioners who are interested in mindfulness disposition and adding their voice to the discussion of teacher effectiveness evaluation.
keywords: mindful disposition, teacher effectivenes
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