Urban epidemiology of labor informality in Bogotá: A neighborhood interactions approach

Usando datos georreferenciados sobre mercado laboral para la ciudad de Bogotá, se desarrolla una estrategia empírica para identificar el efecto de la tasa de informalidad en el vecindario sobre la probabilidad individual de conseguir un trabajo informal. Se encuentra evidencia de la existencia de tales efectos del vecindario. Estos efectos funcionan de forma distinta para informalidad de trabajadores asalariados o independientes.Using geo-referenced data on labor outcomes for the city of Bogotá, we develop a strategy to identify the effect of the neighborhood informality rate on the individual probability of getting an informal job. We found evidence of the existence of such neighborhood effects. Those effects operate differently for salaried informality than for self-employed informality.CEIBA (Centro de Estudios Interdisciplinarios Básicos y Avanzados

Spin-orbit torque induced dipole skyrmion motion at room temperature

We demonstrate deterministic control of dipole-field-stabilized skyrmions by means of spin-orbit torques arising from heavy transition-metal seed layers. Experiments are performed on amorphous Fe/Gd multilayers that are patterned into wires and exhibit stripe domains and dipole skyrmions at room temperature. We show that while the domain walls and skyrmions are achiral on average due to lack of Dzyaloshinskii-Moriya interactions, the N\'eel-like closure domain walls at each surface are chiral and can couple to spin-orbit torques. The current-induced domain evolutions are reported for different magnetic phases, including disordered stripe domains, coexisting stripes and dipole skyrmions and a closed packed dipole skyrmion lattice. The magnetic textures exhibit motion under current excitations with a current density ~10^8 A/m2. By comparing the motion resulting from magnetic spin textures in Fe/Gd films with different heavy transition-metal interfaces, we confirm spin currents can be used to manipulate achiral dipole skyrmions via spin-orbit torques.Comment: 23 pages, 8 figure

Energy-efficient generation of skyrmion phases in Co/Ni/Pt-based multilayers using Joule heating

We have studied the effects of electrical current pulses on skyrmion formation in a series of Co/Ni/Pt-based multilayers. Transmission X-ray microscopy reveals that by applying electrical current pulses of duration and current density on the order of $\tau$=50 $\mu$s and j=1.7x10$^1$$^0$ A/m$^2$, respectively, in an applied magnetic field of $\mu$$_0$Hz=50 mT, stripe-to-skyrmion transformations are attained. The skyrmions remain stable across a wide range of magnetic fields, including zero field. The skyrmions then remain stable across a wide range of magnetic fields, including zero field. We primarily attribute the transformation to current-induced Joule heating on the order of ~125 K. Reducing the magnetic moment and perpendicular anisotropy using thin rare-earth spacers dramatically reduces the pulse duration, current density, and magnetic field necessary to 25 $\mu$s, 2.4x10$^9$ A/m$^2$, and 27 mT, respectively. These findings show that energetic inputs allow for the formation of skyrmion phases in a broad class of materials and that material properties can be tuned to yield more energy-efficient access to skyrmion phases.Comment: 32 pages, 7 figures, 9 supplemental figure

Targeted-pig trial on safety and immunogenicity of serum-derived extracellular vesicles enriched fractions obtained from Porcine Respiratory and Reproductive virus infections

The Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is the etiological agent of one of the most important swine diseases with a significant economic burden worldwide. Unfortunately, available vaccines are partially effective highlighting the need of novel approaches. Previously, antigenic viral proteins were described in serum-derived extracellular vesicles (EVs) from pigs previously infected with PRRSV. Here, a targeted-pig trial was designed to determine the safety and immunogenicity of such extracellular vesicles enriched fractions. Our results showed that immunizations with EV-enriched fractions from convalescence animals in combination with montanide is safe and free of virus as immunizations with up-to two milligrams of EV-enriched fractions did not induce clinical symptoms, adverse effects and detectable viral replication. In addition, this vaccine formulation was able to elicit specific humoral IgG immune response in vaccinated animals, albeit variably. Noticeably, sera from vaccinated animals was diagnosed negative when tested for PRRSV using a commercial ELISA test; thus, indicating that this new approach differentiates vaccinated from infected animals. Lastly, after priming animals with EV-enriched fractions from sera of convalescence animals and boosting them with synthetic viral peptides identified by mass spectrometry, a distinctive high and specific IFN-γ response was elicited. Altogether, our data strongly suggest the use of serum EV-enriched fractions as a novel vaccine strategy against PRRSV.Anti-CD9, Anti-CD63 and anti-CD81 antibodies were kindly donated by Francisco Sánchez-Madrid and Maria Yañez-Mo, Hospital de la Princesa, Madrid, Spain. The authors wish to particularly thank Glòria Abella for her collaboration in conducting the field study and to Marta Alcobé, Miriam Moron Font and Paula Crego Mendez for technical assistance. This study received support from Innovex Therapeutics S.L., Pinsos del Segre SA, Granja Casanyé, Grup de Sanejament Porci (GSP, Lleida, Spain) and the FEDER project (COMRDI16-1-0035-03). Sergio Montanter-Tarbes is an industrial doctorate awarded by the Government of Catalonia, Spain (No. 2014 DI 044). ISGlobal and IGTP are members of the CERCA Programme, Generalitat de Catalunya

Serum-derived exosomes from non-viremic animals previously exposed to the porcine respiratory and reproductive virus contain antigenic viral proteins

PRRSV is the etiological agent of one of the most important swine diseases with a significant economic burden worldwide and limitations in vaccinology. Exosomes are 30–100 nm vesicles of endocytic origin. Remarkably, immunizations with exosomes containing antigens from tumors or pathogens are capable of eliciting protective immune responses, albeit variably, in cancer and infectious diseases. Here we describe the isolation, molecular composition and immunogenicity of serum-derived exosomes from naïve animals, from PRRSV viremic animals and from animals previously PRRSV infected but already free of viruses (non viremic). Exosomes were isolated through size exclusion chromatography and characterized by different methodologies. Exosome-enriched fractions from naïve and natural infected animals contained classical tetraspanin exosomal markers (CD63 and CD81) and high concentrations of particles in the size-range of exosomes as detected by nanoparticle tracking analysis and cryo-TEM. NanoLC-MS/MS was used to identify viral antigens associated to exosomes. PRRSV-proteins were detected in serum samples from only viremic animals and from animals previously infected already free of viruses (non-viremic), but not in controls. Moreover, immune sera from pigs previously exposed to PRRSV specifically reacted against exosomes purified from non-viremic pig sera in a dose-dependent manner, a reactivity not detected when naïve sera was used in the assay. To facilitate future studies, a scaling-up process was implemented. To the best of our knowledge, this is the first molecular characterization of serum-derived exosomes from naïve pigs and pigs actively or previously infected with PRRSV. The presence of antigenic viral proteins in serum-derived exosomes free of virus, suggest their use as a novel vaccine approach against PRRSV.Anti‑ CD63 and anti‑ CD81 antibodies were kindly donated by Francisco Sánchez‑Madrid and Maria Yañez‑Mo, Hospital de la Princesa, Madrid, Spain. We thank Miriam Morón Font for technical assistance and Inés Lozano and Marta Monguió ‑Tortajada for valuable scientific discussions. SMT is supported by an Industrial PhD Fellowship from the government of Catalonia (AGAUR) as part of a collaborative agreement between INNOVEX THERAPEUTICS SL and the University of Lleida (Id No 2014 DI 044

Exosome based vaccines: pros and cons in the world of animal health

Due to the emergence of antibiotic resistance and new and more complex diseases that affect livestock animal health and food security, the control of epidemics has become a top priority worldwide. Vaccination represents the most important and cost‐effective measure to control infectious diseases in animal health, but it represents only 23% of the total global animal health market, highlighting the need to develop new vaccines. A recent strategy in animal health vaccination is the use of extracellular vesicles (EVs), lipid bilayer nanovesicles produced by almost all living cells, including both prokaryotes and eukaryotes. EVs have been evaluated as a prominent source of viral antigens to elicit specific immune responses and to develop new vaccination platforms as viruses and EVs share biogenesis pathways. Preliminary trials with lymphocytic choriomeningitis virus infection (LCMV), porcine reproductive and respiratory syndrome virus (PRRSV), and Marek's disease virus (MDV) have demonstrated that EVs have a role in the activation of cellular and antibody immune responses. Moreover, in parasitic diseases such as Eimeria (chickens) and Plasmodium yoelii (mice) protection has been achieved. Research into EVs is therefore opening an opportunity for new strategies to overcome old problems affecting food security, animal health, and emerging diseases. Here, we review different conventional approaches for vaccine design and compare them with examples of EV‐based vaccines that have already been tested in relation to animal health

Indicadores logísticos en la cadena de suministro como apoyo al modelo Scor

This paper has as its main objective of reviewing, analyzing and propose the use of indicators in different logistics processes  in the supply chain, which range from the supply, warehouse, production, customer service, among others. As a result of developing the document, supported by a previous research work called « Estrategias logísticas para el abastecimiento de las pymes del sector confección del municipio de Itagüí». We obtain indicators to measure the performance of the different logistics process in the supply chain, which becomes the basis to control the use of resources, monitoring compliance targets and identifying opportunities for improvement. The methodology used to determine the indicator was through analysis of professional literature and creation of proprietary indicators from standard reference models of some companies. Additionally, indicators are used to support measurement model SCOR supply chain, which becomes an added value to the academic and business.  Este artículo tiene como principal objetivo revisar, analizar y proponer el uso de indicadores en los diferentes procesos logísticos de la cadena de suministro, los cuales cubren desde el aprovisionamiento pasando por el almacenamiento, la producción, el servicio al cliente, entre otros. Como resultado del desarrollo de un trabajo de investigación llamado « Estrategias logísticas para el abastecimiento de las pymes del sector confección del municipio de Itagüí». Se concluye que los indicadores planteados permiten medir el desempeño de los diferentes procesos logísticos en la cadena de suministro, lo cual, se convierte en la base para control del uso de los recursos, seguimiento al cumplimiento de objetivos e identificación de oportunidades de mejoramiento. La metodología que se utilizó para definir los indicadores fue a través del análisis de bibliografía especializada y la creación de unos indicadores propios a partir de modelos de referencia estándar de algunas empresas. Adicionalmente, los indicadores que se presentan sirven de apoyo a la medición del modelo de cadena de suministro SCOR, lo cual, se convierte en un valor agregado para el ámbito académico y empresarial.   &nbsp

Key Gaps in the Knowledge of the Porcine Respiratory Reproductive Syndrome Virus (PRRSV)

The porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important swine diseases in the world. It is causing an enormous economic burden due to reproductive failure in sows and a complex respiratory syndrome in pigs of all ages, with mortality varying from 2 to 100% in the most extreme cases of emergent highly pathogenic strains. PRRSV displays complex interactions with the immune system and a high mutation rate, making the development, and implementation of control strategies a major challenge. In this review, the biology of the virus will be addressed focusing on newly discovered functions of non-structural proteins and novel dissemination mechanisms. Secondly, the role of different cell types and viral proteins will be reviewed in natural and vaccine-induced immune response together with the role of different immune evasion mechanisms focusing on those gaps of knowledge that are critical to generate more efficacious vaccines. Finally, novel strategies for antigen discovery and vaccine development will be discussed, in particular the use of exosomes (extracellular vesicles of endocytic origin). As nanocarriers of lipids, proteins and nucleic acids, exosomes have potential effects on cell activation, modulation of immune responses and antigen presentation. Thus, representing a novel vaccination approach against this devastating disease

Periodicity staircase in a Fe/Gd magnetic thin film

Presence of multiple competing periodicities may result in a system to go through states with modulated periodicities, an example of which is the self-similar staircase-like structure called the Devil's staircase. Herein we report on a novel staircase structure of domain periodicity in an amorphous and achiral Fe/Gd magnetic thin film wherein the reciprocal space wavevector \textbf{Q} due to the ordered stripe domains does not evolve continuously, rather exhibits a staircase structure. Resonant X-ray scattering experiments show jumps in the periodicity of the stripe domains as a function of an external magnetic field. When resolved in components, the step change along Q$_x$ was found to be an integral multiple of a minimum step height of 7 nm, which resembles closely to the exchange length of the system. Modeling the magnetic texture in the Fe/Gd thin film as an achiral spin arrangement, we have been able to reproduce the steps in the magnetization using a Landau-Lifshitz spin dynamics calculation. Our results indicate that anisotropy and not the dipolar interaction is the dominant cause for the staircase pattern, thereby revealing the effect of achiral magnetism.Comment: 9 pages, 5 figure