Drugs, guns and early motherhood in Colombia

This paper examines the effect of violent crime on the prevalence of early motherhood in Colombia. To instrument for the predominance of violent crime I use geographical and temporal variation in drug trafficking networks. My results suggest that one standard deviation increase in the homicide rate induces a 2.55 percentage points increase in the probability of early motherhoo

Internal cocaine trafficking and armed violence in Colombia

This paper exploits time variation in international cocaine prices and potential trafficking within Colombia to estimate changes in municipality homicide rates

Liquidity constraints, opportunity cost and post-secondary education. Evidence from Colombia

We provide new and clear evidence about the importance of liquidity constraints for post-secondary vocational education. Using two discontinuities that are used to allocate seats in free vocational education and eligibility for educational grants, we exploit the relationship between OLS and IV estimates of returns to education to test for the presence of short run liquidity in the fashion of Card (2001). Eligibility to financial aid increases enrollment in vocational education between 8 to 13 percentage points. Furthermore, we find that when we instrument post-secondary schooling with eligibility for financial aid IV estimates are larger than OLS estimates, suggesting that compliers to this instrument are individuals with high returns to education but who were not enrolling in post-secondary education before due to liquidity constraints. However, when the instrument is not linked with the cost of education IV estimates are not significantly larger than OLS estimates. Our analysis focuses on access to free vocational education, hence our results shed lights on the importance of the opportunity cost.We thank the Jóvenes en Acción impact evaluation team in Econometría S.A. and SEI lead by Marta Isabel Gutierrez. We also want to thank the collaboration of the team in the government offices of DPS, SENA and JeA who provided the data and insights about the institutional context

Wooden-based materials: Eco-friendly materials for direct mass spectrometric analysis and microextraction

Lignocellulosic materials have arisen as a sustainable alternative in microextraction techniques during the last 10 years. As they are natural materials, their use fits into some of the principles of Green Analytical Chemistry. Their inherent porosity, narrow shape, and rigidity permit their use in ambient ionization mass spectrometry techniques. In particular, the combination of wooden-based materials and direct analysis gives birth to the so-called wooden-tip electrospray ionization mass spectrometry technique. This approach has been used for the direct analysis of complex samples, and as a streamlined tool for fingerprint quality analysis. Also, wooden-based materials can be superficially modified to boost the interaction with target compounds, allowing their isolation from complex samples. This review describes the potential and applicability of direct analysis using lignocellulosic materials, as well as other alternatives related to their use in microextraction

Contribución a la simulación virtual de parámetros de calidad acústica en espacios arquitectónicos. Aplicación del método de superficies de respuesta

El análisis acústico de espacios arquitectónicos ha sido ampliamente estudiado en los últimos años. Este análisis se ha enfocado desde diferentes puntos de vista, siendo la simulación uno de ellos. En salas de grandes dimensiones y en particular en aquellas que poseen un determinado valor patrimonial, es muy interesante conocer, además de las condiciones acústicas de la situación actual, las que resulten de futuras intervenciones que puedan conllevar un cambio de uso de dicho espacio. Para ello, es necesario disponer de un modelo fiable que permita prever la variación de estas condiciones ya que cualquier intervención tendente a mejorar su acústica es siempre costosa, tanto en presupuesto como en la posible alteración de la arquitectura interior. Por todo ello, la posibilidad de simular el efecto que pueda tener cualquier cambio en cuanto a las características geométricas de la sala o de los materiales que la componen cobra una especial relevancia. En general, los programas de simulación acústica (Odeon, Caat, etc.) trabajan sobre un modelo tridimensional de la sala y aplican unos valores de los coeficientes de absorción de los materiales de revestimiento, que se toman de la bibliografía o directamente de ensayos, cuando el caso lo permite. Como resultado de esta simulación, se obtienen los valores de los parámetros de calidad, tanto temporales como energéticos, siendo el más importante el tiempo de reverberación en función de la frecuencia (para cada octava o tercio de octava). Por otra parte, se realiza una medición "in situ" de estos parámetros cuyos valores suelen presentar diferencias respecto a los simulados. En estas condiciones se ajustan los resultados procedentes de la simulación a los medidos, hasta conseguir un determinado grado de coincidencia entre ellos. En la actualidad, este ajuste se realiza mediante un método iterativo, generalmente basado en la experiencia del operador, que introduce variaciones razonables de los valores de los coeficienteLlinares Millán, J. (2012). Contribución a la simulación virtual de parámetros de calidad acústica en espacios arquitectónicos. Aplicación del método de superficies de respuesta [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17938Palanci

Liquidity constraints in free post-secondary education: Evidence from Colombia

This paper provides evidence of the importance of liquidity constraints in a tuition-free post-secondary education setting in Colombia. We exploit exogenous variation in the relative cost of tuition-free vocational education from a nationwide cash transfer program. We show that eligibility for a USD 136 grant every other month increases enrollment by up to 12 percentage points. We also show that men with larger returns to education are more affected by the availability of grants, which is consistent with the presence of liquidity constraints. However, we do not find the same for women. This paper highlights the importance of non-tuition costs and discusses whether individuals under-invest in their human capital when free education is available

How do labels and vouchers shape unconditional cash transfers? Experimental evidence from Georgia

We implemented a randomized control trial in Georgia to study how labels and food vouchers affect household expenditure among low-income recipients of unconditional cash transfers. Households were randomly assigned to receive only an unconditional cash transfer, a label indicating an amount intended for children’s expenses in addition to the transfer, or a portion of the transfer as a food voucher usable exclusively at designated stores. We find that labelling increases the share of expenditure on children. Meanwhile, food vouchers reduce total consumption, this being likely due to the increased cost associated with shopping at voucher-accepting shops

The MAL proteolipid is necessary for the overall apical delivery of membrane proteins in the polarized epithelial Madin-Darby canine kidney and Fischer rat thyroid cell lines

The MAL proteolipid has been recently demonstrated as being necessary for correct apical sorting of the transmembrane influenza virus hemagglutinin (HA) in Madin-Darby canine kidney (MDCK) cells. The fact that, in contrast to MDCK cells, Fischer rat thyroid (FRT) cells target the majority of glycosylphosphatidylinositol (GPI)-anchored proteins to the basolateral membrane provides us with the opportunity to determine the role of MAL in apical transport of membrane proteins under conditions in which the majority of GPI-anchored proteins are (MDCK cells) or are not (FRT cells) targeted to the apical surface. Using an antisense oligonucleotide-based strategy to deplete endogenous MAL, we have observed that correct transport of apical transmembrane proteins associated (HA) or not (exogenous neurotrophin receptor and endogenous dipeptidyl peptidase IV) with lipid rafts, as well as that of the bulk of endogenous apical membrane, takes place in FRT cells by a pathway that requires normal MAL levels. Even transport of placental alkaline phosphatase, a GPI-anchored protein that is targeted apically in FRT cells, was dependent on normal MAL levels. Similarly, in addition to the reported effect of MAL on HA transport, depletion of MAL in MDCK cells caused a dramatic reduction in the apical delivery of the GPI-anchored gD1-DAF protein, neurotrophin receptor, and the bulk of membrane proteins. These results suggest that MAL is necessary for the overall apical transport of membrane proteins in polarized MDCK and FRT cellsThis work was supported by grants from the Dirección General de Enseñanza Superior (PM96-0004) and the Comunidad de Madrid (08.3/0020/1998). An institutional grant from the Fundación Ramón Areces to Centro de Biología Molecular "Severo Ochoa" is also acknowledged. F.M.-B, R.P., and J.M. are recipients of fellowships from the Comunidad de MadridPeer reviewe

Design Attributes Influencing the Success of Urban 3D Visualizations: Differences in Assessments According to Training and Intention

[EN] The graphic tools most widely used for communicating the design of future urban spaces are 3D visualizations. These virtual images allow graphic designers to manipulate conditions to embellish the final image they present. But, what design attributes are associated with positive assessments? This paper attempts to identify the key design attributes for a successful proposal and observes whether intention (assess the image versus assess the project) and observer training (architect versus non-architect) influence that relationship. A field study was carried out using assessments from 225 individuals. Results show that color, nature, and architecture are fundamental elements in successful proposals. Significant differences in assessments have also been observed according to the training and intentions of the assessorsThis work was supported by Ministerio de Economía y Competitividad (Spain) [grant no. TIN2013-45736-R].Llinares Millán, MDC.; Iñarra Abad, S.; Guixeres Provinciale, J. (2018). Design Attributes Influencing the Success of Urban 3D Visualizations: Differences in Assessments According to Training and Intention. Journal of Urban Technology. https://doi.org/10.1080/10630732.2018.1444873

Analysis and behavior of different materials in sustainable construction and their alternatives for the improvement of the environment

[EN] The construction sector is widely known for its growing activity and its impact on the environment. The use of different materials within the world of construction has evolved over the years. Thus, thanks to technology, it has been possible to achieve an improvement in the behaviour of certain materials in the world of construction. In this article, different materials from this sector are analysed in order to achieve an improvement and awareness towards a more sustainable construction. The focus has been on the study of the behaviour of these materials and their responses to the phases of construction. As analysed, it has been possible to demonstrate that the controlled evolution of certain materials such as the use of clinker or cementite, significantly improves the context of sustainable construction. On the other hand, by replacing cement by other materials such as fly ash or slag can improve the durability by 50% which is a high figure related to the sustainable point of view, thus can reduce the impact on the environment.This work was supported by the European Union under the project Green Cities for Climate and Water Resilience, Sustainable Economic Growth, Healthy Citizens and Environments with reference 730283 and the framework of Condereff project (Ref. PGI05560-Condereff) Construction & demolition waste management policies for improved resource efficiency.Cárcel-Carrasco, J.; Martínez-Corral, A.; Kaur, J.; Llinares Millán, J. (2021). Analysis and behavior of different materials in sustainable construction and their alternatives for the improvement of the environment. Área de Innovación y Desarrollo,S.L. 131-135. http://hdl.handle.net/10251/19065813113