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Los carnívoros silvestres son propensos a infectarse de enfermedades altamente virulentas y mortales que pueden extinguir poblaciones completas. ¿Podrían herramientas como los biosensores con nanopartículas, ayudar a detectar las enfermedades de este grupo de manera rápida y en campo?

The canine distemper virus (CDV) causes a common fatal disease in carnivores that has led to the local extinction of some species. Timely and effective monitoring and diagnosis of the spread of CDV are essential because these can contribute to containing and planning control strategies in early outbreak stages. The use of nanoparticle-based biosensors (NPs) is a novel alternative. A systematic analysis of NP design, use, and scope provides a clue on the potential application of this technology in CDV diagnosis and control. In this sense, the present paper outlines the most recent findings on the use of biosensors to diagnose canine distemper. We conducted a literature review of the use of biosensors to diagnose different viruses of human and zoonotic importance. Biosensors designed for the diagnosis and control of CDV were then searched and analyzed. Searches were conducted in scientific databases with the keywords "Canine Distemper Virus”, “nanoparticles”, and “biosensors”. No studies on wildlife were found. We found 50 studies addressing the development and application of virus biosensors in domestic animals and under laboratory conditions. The use of metallic NPs with optical properties — for example, gold NPs and quantum dots — have been the main systems for the design of biosensors used in CDV diagnosis and control. Future steps include the application of this technology in widely distributed wildlife species, e. g., coyote, by developing a device with a CDV-specific biosensor for in-situ detection, avoiding the need to capture individuals. Detecting CDV-infected populations in real-time will improve the management and containment of the disease to preserve the health of ecosystems.

Las evaluaciones estandarizadas en el ámbito educativo tienen una larga historia, que inicia a principios de siglo XX. El campo de la Psicología y de la Educación ha impactado enormemente el mundo educativo y, últimamente, ha servido para diseñar políticas públicas y para rendir cuentas a la sociedad. La principal característica de las pruebas estandarizadas es que pueden administrarse a una gran cantidad de personas, cuyas respuestas se califican de manera automática con dispositivos electrónicos. Su gran desventaja radica en que utilizan, principalmente, el formato de selección de respuestas que hace un tanto artificial la evaluación. A pesar de esta limitación, las evaluaciones estandarizadas se utilizan con una gran variedad de propósitos: desde la admisión a instituciones educativas hasta la evaluación de la calidad educativa de un país. A lo largo de su historia, las evaluaciones estandarizadas han sido objeto de críticas, algunas de ellas justas y otras no. Dada su importancia, el propósito de este texto es precisar lo que se entiende por evaluaciones estandarizadas de aprendizaje, describir su origen y evolución en el ámbito educativo, explicar sus principales usos y puntualizar las limitaciones y retos que tendrán.

Los debates en la literatura sobre políticas de ciencia, tecnología e innovación (CTI) argumentan la importancia de reconciliar la oferta y la demanda de conocimientos para enfrentar las desigualdades sociales. En este trabajo, problematizamos la oferta y la demanda de conocimientos científicos en el campo de la nanotecnología (NT) agrícola y alimentaria, en el contexto de un cambio en la concepción de la política de CTI que acompaña la llegada del nuevo gobierno federal en el año 2018. Para operacionalizar estas dimensiones, primero realizamos un mapeo de los proyectos de investigación aprobados por el Consejo Nacional de Ciencia y Tecnología en el periodo 2012-2019. Posteriormente, examinamos las demandas de investigación establecidas por el consejo en torno a los sistemas agroalimentarios. Con ello, discutimos las condiciones de posibilidad que tiene la NT agrícola y alimentaria para responder tales demandas. Concluimos que los cambios en la concepción de ciencia significan nuevas prioridades de investigación para los sistemas agroalimentarios del país, entre ellos, contribuir a la soberanía alimentaria y la sustitución de agroquímicos en el campo; pero más aún, plantean retos para reflexionar sobre: ¿cómo podemos hacer para que la NT agrícola y alimentaria contribuya a alcanzar una agricultura justa con los productores rurales y respetuosa con el ambiente?

Fluorescence resonance energy transfer (FRET) is a high-resolution technique that allows the characterization of spatial and temporal properties of biological structures and mechanisms. In this work, we developed an in silico single-molecule FRET methodology to study the dynamics of fluorophores inside lipid rafts. We monitored the fluorescence of a single acceptor molecule in the presence of several donor molecules. By looking at the average fluorescence, we selected events with single acceptor and donor molecules, and we used them to determine the raft size in the range of 5–16 nm. We conclude that our method is robust and insensitive to variations in the diffusion coefficient, donor density, or selected fluorescence threshold.

Vaccines have saved millions of humans and animals from deadly diseases. Many vaccines are still under development to fight against lethal diseases. Indeed, subunit vaccines are a versatile approach with several advantageous attributes, but they lack strong immunogenicity. Nanotechnology is an avenue to vaccine development because nanoparticles may serve as nanocarriers and adjuvants, which are critical aspects for oral vaccines. This review provides an update of oral organic nanovaccines, describing suitable nanomaterials for oral vaccine design and recent (last five-year view) oral nanovaccine developments to fight against those principal pathogens causing human and animal diseases.

Nanovaccine development is a growing research field in which the development of new carriers and bioconjugation approaches is a priority. In this sense, this report describes for the first time, the development of a novel conjugate that consists of gold nanoparticles (AuNPs) obtained by a one-step synthesis using an immunogenic peptide of the Lipopolysaccharide-assembly protein LptD from Vibrio parahaemolyticus bacteria as a reducing and capping agent. The resulting LptD@AuNPs compounds were fully characterized and the results showed the high capacity of the peptide to form complexes and reduce gold ions. The reaction yield estimated was higher than 83% and the chemical integrity of the peptide on the NP surface revealed a tyrosine amino acid bonding on the AuNP surface. Furthermore, the LptD@AuNP system showed high colloidal stability in a wide pH range (3–11 pH values), where the hydrodynamic diameter and Zeta potential behavior were strongly influenced by the functional groups of the antigenic peptide. The cytotoxicity assays showed that the obtained system is safe for mouse leukocytes, while immunized mice with LptD@AuNPs produced specific IgG antibodies. These encouraging results revealed the efficacy of some antigenic peptides as reducers and capping agents, in addition, opening the path to determine immunogenicity and immunoprotective efficacy of the LptD@AuNP system against the disease induced by Vibrio parahaemolyticus.

Using the Monte Carlo method the x-ray spectrum produced by 150keV electrons colliding with W, Rh and Mo targets were calculated. The x-ray spectra were calculated to 20, 50, and 100cm from the focal point. In order to analyze the effect of the filter, calculations were carried out with and without filter. The spectra were used to estimate the Kerma in air, the Ambient dose equivalent, and the Personal dose equivalent. The spectra were integrated in energy to obtain the total photon fluences. Calculated spectra depend on the type of target having the continuous spectrum due to bremsstrahlung and the characteristics x-rays. The Al filter eliminates the low-energy photons; however no effect is noticed when the photon energy is larger than 40keV. The largest effect of dose reduction due to the filter was noticed to 20cm for the Kerma in air.

Regardless the motivation terrorism is the most important risk for the national security in many countries. Attacks with explosives are the most common method used by terrorists. Therefore several procedures to detect explosives are utilized; among these methods are the use of neutrons and photons. In this study the Monte Carlo method an explosive detection system using a 241AmBe neutron source was designed. In the design light water, paraffin, polyethylene, and graphite were used as moderators. In the work the explosive RDX was used and the induced gamma rays due to neutron capture in the explosive was estimated using NaI(Tl) and HPGe detectors. When light water is used as moderator and HPGe as the detector the system has the best performance allowing distinguishing between the explosive and urea. For the final design the Ambient dose equivalent for neutrons and photons were estimated along the radial and axial axis.

Using Monte Carlo methods a heterogeneous subcritical nuclear reactor was designed. The reactor is a 110 cm-side cube with thorium-based molten salt as fuel, the moderator is graphite and the startup neutron source is 252 Cf. It has ducts to hold the source, the fuel and for irradiation. In the design the k eff was estimated, varying the ducts features and fuel. For the final design, with Th-based salt, the neutron spectra and the ambient dose equivalent due to neutrons, the neutron amplification and the reactor power, were estimated using fresh and burned fuel conditions.

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The aim of this study was to investigate the factors that govern the activity and selectivity of two potent antimicrobial peptides (AMPs) using lipid membrane models of bacterial, erythrocyte and fungal cells. These models were used in calcein liposome leakage experiments to explore peptide efficiency. The AMPs (Pin2 and its variant Pin2[GVG]) showed highest affinity towards the bacterial models in the nanomolar range, followed by the erythrocyte and fungal systems. The presence of sterols modulated the variant's selectivity, while the wild type was unaffected. Liposome leakage experiments with Fluorescein Isothiocyanate-dextran (FITC)-dextran conjugates indicated that pore size depended on peptide concentration. Dynamic Light Scattering revealed peptide aggregation in aqueous solution, and that aggregate size was related to activity. The interacting peptides did not alter liposome size, suggesting pore forming activity rather than detergent activity. Atomic Force Microscopy showed differential membrane absorption, being greater in the bacterial model compared to the mammalian model, and pore-like defects were observed. Electrophysiological assays with the Tip-Dip Patch Clamp method provided evidence of changes in the electrical resistance of the membrane. Membrane potential experiments showed that liposomes were also depolarized in the presence of the peptides. Both peptides increased the Laurdan Generalized Polarization of the bacterial model indicating increased viscosity, on the contrary, no effect was observed with the erythrocyte and the fungal models. Peptide membrane insertion and pore formation was corroborated with Langmuir Pressure-Area isotherms and Brewster Angle Microscopy. Finally, molecular dynamics simulations were used to get an insight into the molecular mechanism of action.

It is well to known that in different knowledge´s areas as research, application and development neutrons are involved either, whether as a product of secondary reactions or applied it to a specific purpose. The Bonner Sphere Spectrometer actually is widely used to detect neutrons using active or passive detectors in health physics and research arenas. The Monte Carlo Code in radiation transport is an effective way to predict absorbed dose distributions and neutron spectra. The aim of this work is design and build a spectrometer as a cubic moderators with the versatility to use passive and active detectors, using Monte Carlo Code to obtain the response matrix, compare the results with SEEB used by others authors. En diversas áreas del conocimiento como investigación, desarrollo o aplicación, los neutrones se encuentran inmersos ya sea como producto secundario de otras reacciones o aplicados con un propósito en particular. El espectrómetro de esferas Bonner es actualmente el sistema más empleado para determinar la energía de los neutrones, usando detectores activos o pasivos, en diferentes ámbitos como la nucleoelectricidad, los rayos cósmicos y la física médica. El uso del código Monte Carlo en el transporte de la radiación nos permite estimar de forma precisa dosis, fluencias y espectros. El objetivo de este trabajo es diseñar un espectrómetro con moderadores cúbicos con la versatilidad de poder emplear tanto detectores pasivos como activos, usando el Código Monte Carlo para obtener las matrices de respuesta, se compararán los resultados con los obtenidos con el SEEB empleado por otros autores.