CIMMYT's Formal Training Activities: Perceptions of Impact from Former Trainees, NARS Research Leaders, and CIMMYT Scientists

This report provides information on the impact of CIMMYT training, based on a set of background interviews with center staff, reviews of relevant data and documents provided by CIMMYT, and two surveys: one of research leaders in trainees’ countries of origin and one of participants in CIMMYT courses on maize and wheat improvement, quality protein maize, soil-borne pathogens of cereals, and maize stress breeding during 2002-04. Evidence indicates that training provided by CIMMYT not only furnishes new knowledge and skills, but results in new ways of thinking about research and new research partnerships, is often shared within trainees’ home institutions, and changes the way the institutions work. The evidence in this study establishes the existence of impact but does not support conclusions about its extent.Training programmes, Training courses, Education, Extension, Agricultural research, Diffusion of research, Evaluation, Research and Development/Tech Change/Emerging Technologies, C10, A50,

Hipercolesterolemia y el polimorfismo del gen SR-B1

Cardiovascular disease is the leading cause of death in the world. The onset of these cardiovascular diseases depends on genetic and environmental factors, where lipid abnormalities, especially dyslipidemia, have a high prevalence in adulthood related to increased obesity and metabolic syndrome. In this sense, the SR-B1 receptor plays an important role in the purification of cholesterol and the selective absorption of HDL located mainly in the liver and also in steroid tissues, by apo A-I, and cholesterol ester are transported in a selective to cells, Although the particle itself, even apo A-I, is not captured by the tissues, but about cholesterol leaving the cells through HDL, which is then carried to the liver for excretion by bile. The aim of this article is to review the current knowledge of the possible association between hypercholesterolemia and 3 polymorphisms (Single Nucleotide Polimorphism; SNP), of the SR-B1 or SCARB1 gene, located on chromosome 12: the SNP’s of exon 1, intron 5 and exon 8.Las enfermedades cardiovasculares son la primera causa de muerte alrededor del mundo. Su aparición depende de factores genéticos y ambientales, donde, las anomalías lipídicas, específicamente las dislipidemias, presentan elevada prevalencia en la edad adulta relacionadas al incremento de la obesidad y síndrome metabólico. En este sentido, el receptor SR-B1  lleva acabo un papel importante en la depuración del colesterol y la captación selectiva de lipoproteínas de alta densidad (HDL) localizadas mayoritariamente en el hígado y en tejidos esteroidogénicos, a través de la apolipoproteina-A (apo A-I) y el colesterol éster, se lleva de manera mas selectiva en las células, se sabe que la apo A-I, no es captada por parte de los tejidos, sino,  por el colesterol que sale de las células a través de la HDL, que enseguida es llevado hacia el hígado para su excreción mediante la bilis. El objetivo del presente artículo es revisar el conocimiento actual de la posible asociación entre la hipercolesterolemia y 3 polimorfismos (Single Nucleótide Polimorphism; SNP), del gen SR-B1 o SCARB1, localizado en el cromosoma 12: los SNP’s del exón 1, del intrón 5 y en el exón 8

Asociación de las dislipidemias con el SNP rs5888 (exón 8) del gen SR-B1

Cardiovascular diseases (CVD) are the leading cause of death from non-communicable diseases in the world, with dyslipidemia appearing as a frequent irregularity and main risk factor. The SCARB1 gene encodes the SR-B1 receptor, which is involved in cholesterol clearance and selective HDL uptake. SR-B1 overexpression decreases HDL-C and atherosclerosis, while its absence increases HDL-C and increases atherosclerosis. Aim. To identify the type of association of dyslipidemias with the rs5888 SNP of the SRB1 gene (exon 8) in an apparently healthy population from the state of Morelos, Mexico. Methodology. From a total of 258 samples, DNA was extracted for its purification and quantification, then exon 8 was genotyped using real-time PCR and using the applied biosystems software, genotypic associations (with SNPs and without SNPs) were performed using the Odds Ratio statistical test. Results. 72.87% of the studied population presented dyslipidemia, with hypoαlipoproteinemia being the most frequent, mostly in men (78.19%). A borderline protective association was found for hypoαlipoproteinemia in those with the rs5888 SNP and a risk association for hypercholesterolemia and hypertriglyceridemia, concluding that a change in the same gene may increase or decrease the probability of developing cardiovascular diseases.Las enfermedades cardiovasculares (ECV) son la primera causa de muerte de las enfermedades no transmisibles en el mundo, figurando las dislipidemias como una irregularidad frecuente y principal factor de riesgo. El gen SCARB1 codifica el receptor SR-B1, el cual participa en la depuración del colesterol y captación selectiva de HDL. La sobre expresión del SR-B1 disminuye el HDL-C y la aterosclerosis, mientras que su ausencia incrementa el HDL-C y eleva la aterosclerosis. Objetivo. Identificar el tipo de asociación de las dislipidemias con el SNP rs5888 del gen SRB1 (exón 8) en población aparentemente sana del estado de Morelos México. Metodología. De un total de 258 muestras, se extrajo ADN para su purificación y cuantificación, posteriormente se realizó la genotipificación del exón 8 mediante PCR en tiempo real y utilizando el software applied biosystems, las asociaciones genotípicas (con SNP y sin SNP) se realizaron por la prueba estadística de Razón de Momios. Resultados. El 72.87 % de la población estudiada presenta dislipidemias, siendo la hipoαlipoproteinemia la más frecuente, mayormente en hombres (78.19 %). Se encontró asociación protectora limítrofe para hipoαlipoproteinemia quienes presenten el SNP rs5888 y asociación de riesgo en hipercolesterolemia e hipertrigliceridemia, concluyendo que un cambio en el mismo gen, pueden aumentar o disminuir la probabilidad de desarrollar enfermedades cardiovasculares

Prospects for hydrogen storage in graphene

Hydrogen-based fuel cells are promising solutions for the efficient and clean delivery of electricity. Since hydrogen is an energy carrier, a key step for the development of a reliable hydrogen-based technology requires solving the issue of storage and transport of hydrogen. Several proposals based on the design of advanced materials such as metal hydrides and carbon structures have been made to overcome the limitations of the conventional solution of compressing or liquefying hydrogen in tanks. Nevertheless none of these systems are currently offering the required performances in terms of hydrogen storage capacity and control of adsorption/desorption processes. Therefore the problem of hydrogen storage remains so far unsolved and it continues to represent a significant bottleneck to the advancement and proliferation of fuel cell and hydrogen technologies. Recently, however, several studies on graphene, the one-atom-thick membrane of carbon atoms packed in a honeycomb lattice, have highlighted the potentialities of this material for hydrogen storage and raise new hopes for the development of an efficient solid-state hydrogen storage device. Here we review on-going efforts and studies on functionalized and nanostructured graphene for hydrogen storage and suggest possible developments for efficient storage/release of hydrogen at ambient conditions

Protein sequences bound to mineral surfaces persist into deep time.

Proteins persist longer in the fossil record than DNA, but the longevity, survival mechanisms and substrates remain contested. Here, we demonstrate the role of mineral binding in preserving the protein sequence in ostrich (Struthionidae) eggshell, including from the palaeontological sites of Laetoli (3.8 Ma) and Olduvai Gorge (1.3 Ma) in Tanzania. By tracking protein diagenesis back in time we find consistent patterns of preservation, demonstrating authenticity of the surviving sequences. Molecular dynamics simulations of struthiocalcin-1 and -2, the dominant proteins within the eggshell, reveal that distinct domains bind to the mineral surface. It is the domain with the strongest calculated binding energy to the calcite surface that is selectively preserved. Thermal age calculations demonstrate that the Laetoli and Olduvai peptides are 50 times older than any previously authenticated sequence (equivalent to ~16 Ma at a constant 10°C)

Spent Culture Medium from Virulent Borrelia burgdorferi Increases Permeability of Individually Perfused Microvessels of Rat Mesentery

Lyme disease is a common vector-borne disease caused by the spirochete Borrelia burgdorferi (Bb), which manifests as systemic and targeted tissue inflammation. Both in vitro and in vivo studies have shown that Bb-induced inflammation is primarily host-mediated, via cytokine or chemokine production that promotes leukocyte adhesion/migration. Whether Bb produces mediators that can directly alter the vascular permeability in vivo has not been investigated. The objective of the present study was to investigate if Bb produces a mediator(s) that can directly activate endothelial cells resulting in increases in permeability in intact microvessels in the absence of blood cells.The effects of cell-free, spent culture medium from virulent (B31-A3) and avirulent (B31-A) B. burgdorferi on microvessel permeability and endothelial calcium concentration, [Ca(2+)](i), were examined in individually perfused rat mesenteric venules. Microvessel permeability was determined by measuring hydraulic conductivity (Lp). Endothelial [Ca(2+)](i), a necessary signal initiating hyperpermeability, was measured in Fura-2 loaded microvessels. B31-A3 spent medium caused a rapid and transient increase in Lp and endothelial [Ca(2+)](i). Within 2-5 min, the mean peak Lp increased to 5.6+/-0.9 times the control, and endothelial [Ca(2+)](i) increased from 113+/-11 nM to a mean peak value of 324+/-35 nM. In contrast, neither endothelial [Ca(2+)](i) nor Lp was altered by B31-A spent medium.A mediator(s) produced by virulent Bb under culture conditions directly activates endothelial cells, resulting in increases in microvessel permeability. Most importantly, the production of this mediator is associated with Bb virulence and is likely produced by one or more of the 8 plasmid(s) missing from strain B31-A

Consensus guidelines for the definition of time-to-event end points in image-guided tumor ablation: results of the SIO and DATECAN initiative

International audienceThere is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue

Functional Analysis of the Borrelia burgdorferi bba64 Gene Product in Murine Infection via Tick Infestation

Borrelia burgdorferi, the causative agent of Lyme borreliosis, is transmitted to humans from the bite of Ixodes spp. ticks. During the borrelial tick-to-mammal life cycle, B. burgdorferi must adapt to many environmental changes by regulating several genes, including bba64. Our laboratory recently demonstrated that the bba64 gene product is necessary for mouse infectivity when B. burgdorferi is transmitted by an infected tick bite, but not via needle inoculation. In this study we investigated the phenotypic properties of a bba64 mutant strain, including 1) replication during tick engorgement, 2) migration into the nymphal salivary glands, 3) host transmission, and 4) susceptibility to the MyD88-dependent innate immune response. Results revealed that the bba64 mutant's attenuated infectivity by tick bite was not due to a growth defect inside an actively feeding nymphal tick, or failure to invade the salivary glands. These findings suggested there was either a lack of spirochete transmission to the host dermis or increased susceptibility to the host's innate immune response. Further experiments showed the bba64 mutant was not culturable from mouse skin taken at the nymphal bite site and was unable to establish infection in MyD88-deficient mice via tick infestation. Collectively, the results of this study indicate that BBA64 functions at the salivary gland-to-host delivery interface of vector transmission and is not involved in resistance to MyD88-mediated innate immunity