Venezuela's Growth Experience

The standard of living, measured as gross domestic product (GDP) per capita, increased dramatically in Venezuela relative to that of the United States from 20 percent in 1920 to 90 percent in 1958, but since then has collapsed to around 30 percent nowadays. What explains these remarkable growth and collapse episodes? Using a standard development accounting framework, we show that the growth episode is mainly accounted for by an increase in capital accumulation and knowledge transfer associated with the foreign direct investment in the booming oil industry. The collapse episode is accounted for equally by a fall in total factor productivity and in capital accumulation. We analyze Venezuela during the collapse episode in the context of a model of heterogeneous production units were policies and institutions favour unproductive in detriment of more productive activities. These policies generate misallocation, lower TFP, and a decline in capital accumulation. We show in the context of an heterogeneous-establishment growth model that distortionary policies can explain between 80 to 95 percent of the current differences in TFP, capital accumulation, and income per capita between Venezuela and the United States.Productivity, physical capital, misallocation, policies

Towards a single-photon energy-sensitive pixel readout chip: pixel level ADCs and digital readout circuitry

Unlike conventional CMOS imaging, a single\ud photon imager detects each individual photon impinging on\ud a detector, accumulating the number of photons during a\ud certain time window and not the charge generated by the all\ud the photons hitting the detector during said time window.\ud The latest developments in the semiconductor industry\ud are allowing faster and more complex chips to be designed\ud and manufactured. With these developments in mind we are\ud working towards the next step in single photon X-ray imaging:\ud energy sensitive pixel readout chips. The goal is not only\ud to detect and count individual photons, but also to measure\ud the charge deposited in the detector by each photon, and\ud consequently determine its energy. Basically, we are aiming\ud at a spectrometer-in-a-pixel, or a “color X-ray camera”.\ud The approach we have followed towards this goal is the\ud design of small analog-to-digital-converters at the pixel level,\ud together with a very fast digital readout from the pixels to\ud the periphery of the chip, where the data will be transmitted\ud off-chip.\ud We will present here the design and measurement on prototype\ud chips of two different 4-bit pixel level ADCs. The\ud ADCs are optimized for very small area and low power, with\ud a resolution of 4-bits and a sample rate of 1 Msample/s. The\ud readout architecture is based around current-mode sense\ud amplifiers and asynchronous token-passing between the pixels.\ud This is done in order to achieve event-by-event readout\ud and, consequently, on-line imaging. We need to read eventby-\ud event (photon-by-photon), because we cannot have memory\ud on the pixels due to obvious size constraints. We use\ud current-mode sense amplifiers because they perform very\ud well in similar applications as very fast static-RAM readout

Anomalously large capacitance of a plane capacitor with a two-dimensional electron gas

In electronic devices where a two-dimensional electron gas (2DEG) comprises one or both sides of a plane capacitor, the resulting capacitance $C$ can be larger than the "geometric capacitance" $C_g$ determined by the physical separation $d$ between electrodes. This larger capacitance is known to result from the Coulomb correlations between individual electrons within the low density 2DEG, which lead to a negative thermodynamic density of states (negative compressibility). Experiments on such systems generally operate in the regime where the average spacing between electrons $n^{-1/2}$ in the 2DEG is smaller than $d$, and these experiments observe $C > C_g$ by only a few percent. A recent experiment [1], however, has observed $C$ larger than $C_g$ by almost 40% while operating in the regime $nd^2 << 1$. In this paper we argue that at $nd^2 << 1$ correlations between the electronic charge of opposite electrodes become important. We develop a theory of the capacitance for the full range of $nd^2$. We show that, in the absence of disorder, the capacitance can be $4d/a$ times larger than the geometric value, where $a << d$ is the electron Bohr radius. Our results compare favorably with the experiment of Ref. [1] without the use of adjustable parameters.Comment: 8 pages, 6 figures; revised discussion of the zero density limit; some typos fixe

Venezuela’s Growth Experience

The standard of living, measured as gross domestic product (GDP) per capita, increased dramatically in Venezuela relative to that of the United States from 20 percent in 1920 to 90 percent in 1958, but since then has collapsed to around 30 percent nowadays. What explains these remarkable growth and collapse episodes? Using a standard development accounting framework, we show that the growth episode is mainly accounted for by an increase in capital accumulation and knowledge transfer associated with the foreign direct investment in the booming oil industry. The collapse episode is accounted for equally by a fall in total factor productivity and in capital accumulation. We analyze Venezuela during the collapse episode in the context of a model of heterogeneous production units were policies and institutions favour unproductive in detriment of more productive activities. These policies generate misallocation, lower TFP, and a decline in capital accumulation. We show in the context of an heterogeneous-establishment growth model that distortionary policies can explain a large portion of the current differences in TFP, capital accumulation, and income per capita between Venezuela and the United States.Productivity, physical capital, misallocation, policies

Los depósitos lacustres del Terciario de Bicorp (Valencia)

La Cuenca de Bicorp pertenece al conjunto de cuencas sinorogénicas del Terciario de la província de Valencia. Está emplazada en el sector sur de la zoia de transición entre la cadena  ibérica y las Béticas. La Cuenca de Bicorp es una cuenca continental emplazada sobre un substrato mesozoico formado por materiales triásicos, jurásicos y cretácicos. Sus limites norte y sur son dos fallas normales de orientación ENE-WSW, las cuales actuaron sinsedimentariamente. Los depósitos de la Cuenca de Bicorp tienen un espesor máximo de 450 metros. La base de la serie está formada por materiales de origen aluvial, mientras que el resto lo constituyen facies lacustres. En los depósitos lacustres pueden reconocerse cuatro unidades formadas, desde la base hacia el techo, por: a) margas carbonosas grises, b) calizas laminadas y margas con lignito, c) yesos seleniticos y d) alternancias de calizas y pelitas laminadas bituminosas. De estas unidades la que posee los depósitos de mayor potencia y extensión areal, es la formada por las alternancias de calizas y pelitas bituminosas. Estos son los materiales que caracterizan mejor la serie de la cuenca lacustre de Bicorp. Las alternancias de calizas y pelitas bituminosas están organizadas en secuencias, estrato- y granocrecientes hacia el techo, que se repiten cíclicamente. Cada secuencia está formada por un término superior de calizas y otro inferior de pelitas bituminosas. Las calizas están compuestas, en su mayor parte, por restos esqueléticos de invertebrados acuáticos, y presentan en su techo evidencias de emersión subarea (grietas de desecación, huellas de vertebrados terrestres...). Las pelitas bituminosas se caracterizan por su alto contenido en materia orgánica y por tener una laminación continua milimétrica. Sus características son indicativas de haber sido formadas en un ambiente sin el contenido de oxigeno necesario para permitir la presencia de fauna bentónica en el fondo. En su conjunto, los depósitos de la Cuenca de Bicorp son representativos de un ambiente lacustre salino con unestado permanente de estratificación de sus aguas y con un epilimnion oxigenado y un hipolimnion anóxico

A MegaCam Survey of Outer Halo Satellites. VII. A Single S\'ersic Index v/s Effective Radius Relation for Milky Way Outer Halo Satellites

In this work we use structural properties of Milky Way's outer halo ($R_G > 25\,\mathrm{kpc}$) satellites (dwarf spheroidal galaxies, ultra-faint dwarf galaxies and globular clusters) derived from deep, wide-field and homogeneous data, to present evidence of a correlation in the S\'ersic index v/s effective radius plane followed by a large fraction of outer halo globular clusters and satellite dwarf galaxies. We show that this correlation can be entirely reproduced by fitting empirical relations in the central surface brightness v/s absolute magnitude and S\'ersic index v/s absolute magnitude parameter spaces, and by assuming the existence of two types of outer halo globular clusters: one of high surface brightness (HSB group), with properties similar to inner halo clusters; and another of low surface brightness (LSB group), which share characteristics with dwarf spheroidal and ultra-faint dwarf galaxies. Given the similarities of LSB clusters with dwarf spheroidal and ultra-faint dwarf galaxies, we discuss the possibility that outer halo clusters also originated inside dark matter halos and that tidal forces from different galaxy host's potentials are responsible for the different properties between HSB and LSB clusters.Comment: 20 pages, 9 figures, 3 table

Knowledge About the Human Papillomavirus Vaccine Among Employees at a Tertiary Cancer Center: Room for Improvement

Introduction: The human papillomavirus (HPV) vaccine is recommended by the U.S. Centers for Disease Control and Prevention for routine vaccination of boys and girls to protect against HPV-related cancers and genital warts. To meet the Healthy People 2020 target for HPV vaccination, health care providers must understand the importance of strongly recommending the HPV vaccine to all eligible adolescents. We sought to determine HPV vaccination patterns among employees at a tertiary cancer center and their children and attitudes regarding HPV vaccination among the employees. Methods: All employees at a tertiary cancer center were invited to participate in a cross-sectional survey administered online during July and August 2015. The survey included questions about HPV vaccination of participants and their children, including reasons why vaccine-eligible employees and children had not been vaccinated. Results: Of those eligible, 13% of male and 33% of female employees and 44% of daughters and 24% of sons of employees had completed the vaccine series. The main reasons for not completing the series or not having one’s son completing the series were not knowing that the vaccine was needed and vaccine not recommended by a health care provider. The main reasons for not having one’s daughter complete the series were the two aforementioned reasons and daughter not yet sexually active. Conclusion: Opportunities exist to educate health care workers about the benefits of the HPV vaccine and to increase the number of providers who recommend HPV vaccination to their patients

Changes in volatile compounds during ripening of Chorizo de Pamplona elaborated with Lactobacillus plantarum and Staphylococcus carnosus.

The ripening of chorizo de Pamplona was followed through the changes of the volatile compounds extracted by a simultaneous destilation-extraction with dichloromethane. An increase of the number and concentration of compounds was detected during the maturation, ranging from 63 compounds (10.26 mg dodecane/g dry matter) to 98 substances (223.16 mg of dodecane/g dry matter) identified in the mixing and in the final product, respectively. Acids showed the highest increase during the ripening, reaching 90% of the total amount of compounds at the end of the process, followed by esters and aldehydes. Short chain fatty acids, which contributed to the typical organoleptic charac teristics of dry fermented sausages, became apparent from the 21st day and accounted for only 1.3 mg of the total of acids in final product (202 mg dodecane/g dry matter). Sulphur compounds decreased slightly during the ripening, a result of the decrease in the content of the disulphide di- 2-propenyl, a compound originated from garlic

Combining social-based data mining techniques to extract collective trends from twitter

Social Networks have become an important environment for Collective Trends extraction. The interactions amongst users provide information of their preferences and relationships. This information can be used to measure the influence of ideas, or opinions, and how they are spread within the Network. Currently, one of the most relevant and popular Social Networks is Twitter. This Social Network was created to share comments and opinions. The information provided by users is especially useful in different fields and research areas such as marketing. This data is presented as short text strings containing different ideas expressed by real people. With this representation, different Data Mining techniques (such as classification or clustering) will be used for knowledge extraction to distinguish the meaning of the opinions. Complex Network techniques are also helpful to discover influential actors and study the information propagation inside the Social Network. This work is focused on how clustering and classification techniques can be combined to extract collective knowledge from Twitter. In an initial phase, clustering techniques are applied to extract the main topics from the user opinions. Later, the collective knowledge extracted is used to relabel the dataset according to the clusters obtained to improve the classification results. Finally, these results are compared against a dataset which has been manually labelled by human experts to analyse the accuracy of the proposed method.The preparation of this manuscript has been supported by the Spanish Ministry of Science and Innovation under the following projects: TIN2010-19872 and ECO2011-30105 (National Plan for Research, Development and Innovation), as well as the Multidisciplinary Project of Universidad Autónoma de Madrid (CEMU2012-034). The authors thank Ana M. Díaz-Martín and Mercedes Rozano for the manual classification of the Tweets