An Empirical Analysis of Mark-ups in the Argentine Manufacturing Sector

In this paper, we estimate mark-ups with plant level production data for Argentina from a structural model of cost-minimizing producers, as proposed by De Loecker and Warzynski (2012). We explore systematic differences across industries and plants. Our main findings are that mark-ups are higher in capital-intensive industries, and for plants that are more productive, larger, and more capital-intensive. Our findings are consistent with theories that predict larger mark-ups for more efficient firms and for higher quality products.Fil: Brambilla, María Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas; ArgentinaFil: Tortarolo, Darío. Berkeley University; Estados Unidos. Universidad Nacional de La Plata; Argentin

Female labor supply and fertility : Causal evidence for Latin America

In this paper I study the causal relationship between fertility and female labor supply using census data from 14 Latin American countries and the U.S. over the span of three decades (1980, 1990 and 2000). Parental preferences for a gender-balanced family (mixed-sex children) is exploited as a source of exogenous variation in fertility. Although OLS estimates suggest a statistically signi cant negative relationship in the 39 censuses used, instrumental variables approach fails to identify a causal e ect in most of them. The average e ect of moving from a family with two children to more than two is statistically zero for the group of compliers. Considering a pool of married women from Latin America over the span of three decades, a negative causal e ect is found. In any case, despite having a highly accurate rst-stage and indirect evidence consistent with the internal validity of the instrument, the analysis of the quality of the instrument reveals a weak explanatory power of sibling sex composition on fertility. The noisy and imprecise IV estimates for Latin America in the second-stage can be attributed to the problem of weak instruments.Centro de Estudios Distributivos, Laborales y Sociales (CEDLAS

Fertilidad y oferta de trabajo femenino. Relación causal para América Latina

This paper studies the causal relationship between fertility and female labor supply using census data from 14 Latin American countries and the U.S. over three decades (1980, 1990 and 2000). Parental preferences for a gender-balanced family is exploited as a source of exogenous variation. Although OLS estimates suggest a negative relationship, instrumental variables fails to identify a causal effect in most countries. When considering a pool of married women, a negative causal effect is found. In any case, despite having a highly accurate first-stage, the analysis of the quality of the instrument reveals a weak explanatory power of sibling sex composition on fertility.Este artículo estudia la relación causal entre fertilidad y oferta de trabajo femenino usando datos censales de 14 países de Latinoamérica y EE.UU en un período de tres décadas (1980s, 1990s y 2000s). La preferencia de los padres por una estructura familiar balanceada (en términos de género) se utiliza como fuente de variación exógena. Aunque las estimaciones de MCO sugieren una relación negativa, el método de variables instrumentales no identifica un efecto para la mayor parte de los países. Considerando las mujeres casadas se obtiene un efecto negativo. El análisis de la calidad del instrumento revela un débil poder explicativo del género sobre la fertilidad

Laser Scanning Microscopy with SPAD Array Detector: Towards a New Class of Fluorescence Microscopy Techniques

Laser scanning microscopy is one of the most common architectures in fluorescence microscopy. In a nutshell: the objective lens focuses the laser beam(s) and generates an effective excitation spot which is scanned on the sample; for each pixel, the fluorescent image is projected into a single-element detector, which \u2013 typically \u2013 spatially and temporally integrates the fluorescent light along its sensitive area and the pixel dwell-time, thus providing a single-intensity value per pixel. Notably, the integration performed by the single-element detector hinders any additional information potentially encoded in the dynamic and image of the fluorescent spot. To address this limitation, we recently upgraded the detection unit of a laser scanning microscope, replacing the single-element detector with a novel SPAD (single photon avalanche diode) array detector. We have shown at first that the additional spatial information allows to overcome the trade-off between resolution and signal-to-noise ratio proper of confocal microscopy: indeed, this architecture represents the natural implementation of image scanning microscopy (ISM). We then exploited the single-photon-timing ability of the SPAD array detector elements to combine ISM with fluorescence lifetime imaging: the results show higher resolution and better lifetime accuracy with respect to the confocal counterpart. Moreover, we explored the combination of our ISM platform with stimulated emission depletion (STED) microscopy, to mitigate the non-negligible chance of photo-damaging a sample. Lastly, we showed how the SPAD array-based microscope can be used in the context of single-molecule/particle tracking (SMT or SPT) and spectroscopy. Indeed, we implemented a real-time, feedback based SMT architecture which can potentially correlate the dynamics of a bio-molecule with its structural changes and micro-environment, taking advantage of the time-resolved spectroscopy ability of the novel detector. We believe that this novel laser scanning microscopy architecture has everything in its favour to substitute current single-element detector approaches; it will enable for a new class of fluorescence microscopy techniques capable of investigating complex living biological samples with unprecedented spatial and temporal characteristics and augmented information content

Role of excitotoxicity in the degeneration of motor neurones in ALS

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder involving selective degeneration of motor neurones. In a proportion of patients, ALS is caused by mutations in copper/zinc superoxide dismutase (SOD1), and mice expressing these mutants develop a syndrome that resembles human ALS. Using SOD1G93A transgenic mice, the role of glutamate-mediated toxicity and related intracellular pathways in motor neurone death has been investigated. GluR2 AMPA receptor subunits were decreased in spinal motor neurones of SOD1G93A mice before symptom onset. Since GluR2-lacking receptors are highly permeable to Ca2+, a known trigger of excitotoxic neuronal death, this phenomenon may have a pathogenic role. In support of this, treatment with an AMPA antagonist, ZK-187638, ameliorated motor symptoms and prolonged the survival of SOD1G93A mice. GluR2-lacking receptors are also permeable to zinc, which can be highly toxic. In situ hybridisation showed low expression of the zinc extruder ZnT-1 on motor neurones, which may contribute to their vulnerability to excitotoxicity. Expression of glutamate transporters on astrocytes may also contribute to excitotoxic motor neurone death. In transgenic mice and in astrocytes transfected with SOD1G93A, immunocytochemistry. Western blotting, in situ hybridisation and RT-PCR revealed down-regulation of GLT-1 protein, but not mRNA in astrocytes. However, the time-course in mice suggests that GLT-1 downregulation is not a primary pathological event. Activation of p38MAPK, a kinase putatively involved in glutamate mediated neurotoxicity, was observed in motor neurones at the onset of the disease, but SB 239063, a p38MAPK inhibitor, did not ameliorate motor dysfunction or survival of SOD1G93A mice. Altogether the results suggest that AMPA receptor mediated excitotoxicity is a primary cause of motor neurone degeneration in ALS. These observations may contribute to the development of new therapeutic strategies for this devastating disease