Detección de marcadores microsatélites asociados con la resistencia al añublo bacterial de la yuca (Manihot esculenta Crantz) en Colombia

Una de las principales estrategias para el manejo del Añublo Bacterial de la Yuca (CBB), causado por Xanthomonas axonopodis pv. manihotis es el uso de resistencia varietal, que implica desarrollar variedades de yuca con resistencia genética duradera. Para tal fin, es necesario conocer los genes que dominan la resistencia a la enfermedad, detectando inicialmente marcadores moleculares asociados con la respuesta fenotipica de la planta, siendo este el principal objetivo del presente estudio. Inicialmente, se evaluó la reacción a CBB de 4 familias de yuca BCI (retrocruce 1), se seleccionó la más segregante bajo presión natural de inóculo en Villavicencio (Meta, Colombia) y se confirmó la respuesta a CBB en condiciones de invernadero en CIAT (Palmira, Valle). La familia GM 315 presentó la mejor segregación, siendo la más adecuada para buscar asociación entre su reacción fenotípica y la presencia de un marcador molecular. Para esto, se evaluaron 486 cebadores microsatélites mediante análisis de grupos segregantes (BSA), encontrándose que 17 de ellos mostraron polimorfismo entre los grupos contrastantes y solo uno de ellos, el cebador SSRY 65, mostró diferencias significativas entre individuos resistentes y susceptibles. Al evaluar este cebador en toda la familia segregante se encontró asociación entre su presencia y los individuos evaluados fenotípicamente como resistentes en campo e invernadero, con una probabilidad mínima de P=0,OOl5 y P=0,OO7 respectivamente, en una prueba de Chicuadrado de independencia. Adicionalmente, a partir de los resultados obtenidos en el análisis estadístico, se calcularon los valores predictivos, especificidad y sensibilidad del marcador SSRY 65. Con base en los valores predictivos positivos generados, es posible sugerir la utilización de este marcador en pruebas diagnósticas para detectar la presencia de una banda específica en individuos resistentes de familias genéticamente relacionadas con la familia GM 315. = A major strategy for managing Cassava Bacterial blight (CBB), caused by Xanthomonas axonopodis pv. manihotis, is to use varietal resistance, that is, to develop cassava varieties with lasting genetic resistance. A search for the genes that dominate resistance to the disease was initially conducted by seeking the molecular markers associated with the plant s phenotypic response to CBB. The response in four BC1 (backcross 1) cassava families was accordingly evaluated under natural disease pressure at Villavicencio (Meta, Colombia). The most segregating family was then selected, and its response to CBB was verified under greenhouse conditions at CIAT (Palmira, Valle). Family GM 315 presented the best segregation, so, it was the most suitable for seeking association between its phenotypic reaction and the presence of a molecular marker. Of 486 microsatellite primers evaluated by bulked segregant analysis (BSA), 17 showed polymorphism among contrasting groups. Only one primer, SSRY 65, showed significant differences between resistant and susceptible individuals. On evaluating this primer for the entire segregating family, an association was found between its presence and individuals evaluated phenotypically as resistant in the field and greenhouse (minimum P = 0.0015 and P = 0.007, respectively, in a chi-square test of independence). With the results of the statistical analysis, the predictive values, specificity, and sensibility of marker SSRY 65 were calculated. The positive predictive values generated indicate that this marker can be used in diagnostic tests to detect the presence of a specific band in resistant individuals of families genetically related to the GM 315 family

Two-wavelength switching with a distributed-feed back semiconductor optical amplifier (DFBSOA)

Switching of a signal beam by another control beam at different wavelength is demonstrated experimentally using the optical bistability occurring in a 1.55 mm-distributed feedback semiconductor optical amplifier (DFBSOA) working in reflection. Counterclockwise (S-shaped) and reverse (clockwise) bistability are observed in the output of the control and the signal beam respectively, as the power of the input control signal is increased. With this technique an optical signal can be set in either of the optical input wavelengths by appropriate choice of the powers of the input signals. The switching properties of the DFBSOA are studied experimentally as the applied bias current is increased from below to above threshold and for different levels of optical power in the signal beam and different wavelength detunings between both input signals. Higher on-off extinction ratios, wider bistable loops and lower input power requirements for switching are obtained when the DFBSOA is operated slightly above its threshold value

Boolean analysis identifies CD38 as a biomarker of aggressive localized prostate cancer.

The introduction of serum Prostate Specific Antigen (PSA) testing nearly 30 years ago has been associated with a significant shift towards localized disease and decreased deaths due to prostate cancer. Recognition that PSA testing has caused over diagnosis and over treatment of prostate cancer has generated considerable controversy over its value, and has spurred efforts to identify prognostic biomarkers to distinguish patients who need treatment from those that can be observed. Recent studies show that cancer is heterogeneous and forms a hierarchy of tumor cell populations. We developed a method of identifying prostate cancer differentiation states related to androgen signaling using Boolean logic. Using gene expression data, we identified two markers, CD38 and ARG2, that group prostate cancer into three differentiation states. Cancers with CD38-, ARG2- expression patterns, corresponding to an undifferentiated state, had significantly lower 10-year recurrence-free survival compared to the most differentiated group (CD38+ARG2+). We carried out immunohistochemical (IHC) staining for these two markers in a single institution (Stanford; n = 234) and multi-institution (Canary; n = 1326) cohorts. IHC staining for CD38 and ARG2 in the Stanford cohort demonstrated that combined expression of CD38 and ARG2 was prognostic. In the Canary cohort, low CD38 protein expression by IHC was significantly associated with recurrence-free survival (RFS), seminal vesicle invasion (SVI), extra-capsular extension (ECE) in univariable analysis. In multivariable analysis, ARG2 and CD38 IHC staining results were not independently associated with RFS, overall survival, or disease-specific survival after adjusting for other factors including SVI, ECE, Gleason score, pre-operative PSA, and surgical margins

Characterization, selection and micro-assembly of nanowire laser systems

Semiconductor nanowire (NW) lasers are a promising technology for the realization of coherent optical sources with ultrasmall footprint. To fully realize their potential in on-chip photonic systems, scalable methods are required for dealing with large populations of inhomogeneous devices that are typically randomly distributed on host substrates. In this work two complementary, high-throughput techniques are combined: the characterization of nanowire laser populations using automated optical microscopy, and a high-accuracy transfer-printing process with automatic device spatial registration and transfer. Here, a population of NW lasers is characterized, binned by threshold energy density, and subsequently printed in arrays onto a secondary substrate. Statistical analysis of the transferred and control devices shows that the transfer process does not incur measurable laser damage, and the threshold binning can be maintained. Analysis on the threshold and mode spectra of the device populations proves the potential for using NW lasers for integrated systems fabrication

The aryl hydrocarbon receptor ligand FICZ improves left ventricular remodeling and cardiac function at the onset of pressure overload-Induced heart failure in mice

Adverse ventricular remodeling is the heart’s response to damaging stimuli and is linked to heart failure and poor prognosis. Formyl-indolo [3,2-b] carbazole (FICZ) is an endogenous ligand for the aryl hydrocarbon receptor (AhR), through which it exerts pleiotropic effects including protection against inflammation, fibrosis, and oxidative stress. We evaluated the effect of AhR activation by FICZ on the adverse ventricular remodeling that occurs in the early phase of pressure overload in the murine heart induced by transverse aortic constriction (TAC). Cardiac structure and function were evaluated by cardiac magnetic resonance imaging (CMRI) before and 3 days after Sham or TAC surgery in mice treated with FICZ or with vehicle, and cardiac tissue was used for biochemical studies. CMRI analysis revealed that FICZ improved cardiac function and attenuated cardiac hypertrophy. These beneficial effects involved the inhibition of the hypertrophic calcineurin/NFAT pathway, transcriptional reduction in pro-fibrotic genes, and antioxidant effects mediated by the NRF2/NQO1 pathway. Overall, our findings provide new insight into the role of cardiac AhR signaling in the injured heart.This research was supported by Grants SAF2017-84777-R, funded by the Ministry of Economy and Competitiveness (MINECO) of Spain, PID2020-113238RB-I00 funded by the Ministry of Science and Innovation (MCIN)/AEI/ 10.13039/501100011033 of Spain and the “European Union Next GenerationEU/PRTR”; PI20/01482-1 funded by the Instituto de Salud Carlos III, CB16/11/00222 funded by the Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV) and a Grant (Proyectos 2021) financed by the Universidad Francisco de Vitoria

Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry

Rationale The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently the technique of choice for VOC analysis is gas chromatography-mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique has led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet-pump based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis. Methods Volatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis was used to differentiate between different classes of samples. Results The interface is shown to able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter-day reproducibility using an unsupervised principal component analysis model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 µg/ml and 1.316 µg/ml respectively, and then applied to measure indole in aged pork samples. Conclusions The methodology described has shown to be able to routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system is demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats

MoS₂ Thin Films for Photo-Voltaic Applications

The low dimensional chalcogenide materials with high band gap of ~1.8 eV, specially molybdenum di-sulfide (MoS2), have been brought much attention in the material science community for their usage as semiconducting materials to fabricate low scaled electronic devices with high throughput and reliability, this includes also photovoltaic applications. In this chapter, experimental data for MoS2 material towards developing the next generation of high-efficiency solar cells is presented, which includes fabrication of ~100 nm homogeneous thin film over silicon di-oxide (SiO2) by using radio frequency sputtering at 275 W at high vacuum~10−9 from commercial MoS2 99.9% purity target. The films were studied by means of scanning and transmission electron microscopy with energy disperse spectroscopy, grazing incident low angle x-ray scattering, Raman spectroscopy, atomic force microscopy, atom probe tomography, electrical transport using four-point probe resistivity measurement as well mechanical properties utilizing nano-indentation with continuous stiffness mode (CSM) approach. The experimental results indicate a vertical growth direction at (101)-MoS2 crystallites with stacking values of 7-laminates along the (002)-basal plane; principal Raman vibrations at E12g at 378 cm−1 and A1g at 407 cm−1. The hardness and elastic modulus values of H = 10.5 ± 0.1 GPa and E = 136 ± 2 GPa were estimated by CSM method from 0 to 90 nm of indenter penetration; as well transport measurements from −3.5 V to +3.5 V indicating linear Ohmic behavior