Riboswitch RSthiT as a molecular tool in Lactococcus lactis

Previous RNA sequencing has allowed the identification of 129 long 5′ untranslated regions (UTRs) in the Lactococcus lactis MG1363 transcriptome. These sequences potentially harbor cis-acting riboswitches. One of the identified extended 5′ UTRs is a putative thiamine pyrophosphate (TPP) riboswitch. It is located immediately upstream of the thiamine transporter gene thiT (llmg_0334). To confirm this assumption, the 5′-UTR sequence was placed upstream of the gene encoding the superfolder green fluorescent protein (sfGFP), sfgfp, allowing the examination of the expression of sfGFP in the presence or absence of thiamine in the medium. The results show that this sequence indeed represents a thiamine-responsive TPP riboswitch. This RNA-based genetic control device was used to successfully restore the mutant phenotype of an L. lactis strain lacking the major autolysin gene, acmA. The L. lactis thiT TPP riboswitch (RS(thiT)) is a useful molecular genetic tool enabling the gradual downregulation of the expression of genes under its control by adjusting the thiamine concentration. IMPORTANCE The capacity of microbes with biotechnological importance to adapt to and survive under quickly changing industrial conditions depends on their ability to adequately control gene expression. Riboswitches are important RNA-based elements involved in rapid and precise gene regulation. Here, we present the identification of a natural thiamine-responsive riboswitch of Lactococcus lactis, a bacterium used worldwide in the production of dairy products. We used it to restore a genetic defect in an L. lactis mutant and show that it is a valuable addition to the ever-expanding L. lactis genetic toolbox

Comparative study of real-time pcr (Taqman probe and sybr green), serological techniques (elisa, ifa and dat) and clinical signs evaluation, for the diagnosis of canine leishmaniasis in experimentally infected dogs

Canine leishmaniasis (CanL) diagnosis is not fully resolved. Currently, two specific methodologies are in continuous development, the detection of the parasite DNA or RNA in target organs and the detection of specific antibodies against Leishmania sp. For a correct diagnosis, it has been shown that the joint use of this type of test is necessary. In this work, a Sybr Green and a TaqMan Probe based on real time PCRs (qPCR) was performed for the detection of Leishmania sp. in order to correlate the results with clinicopathological and serological evaluations (IFA, ELISA and DAT) to propose an optimal biological sample to be used to detect the parasite in both early and late stages of the infection. A total of four samples were processed: conjunctival swabs, popliteal lymph node aspirates, bone marrow aspirates, and peripheral blood from experimentally infected dogs belonging to a larger study. Our results indicated that a single non-invasive sample (conjunctival swab) and the application of both types of qPCR would be reliable for determining Leishmania infection as well as the disease stage in dogs, thus avoiding bone marrow, lymph node aspirate or blood samples collection. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/)

Software público, libre, abierto, gratuito, privativo y comercial para la innovación y mejora de la calidad en la docencia, investigación, gestión y asistencia

The public free software (now renamed as open software) is the basis of the open source software (OSS) project. This initiative promotes the use of open standards and platform-independent accessibility. Many OSS products are free or low cost, which allows their deployment even in the absence of large economic resources (developing countries, schools, etc.). Besides, their source code can be modified, adapted and optimized by anyone, since it is public. Nevertheless, the OSS may also have drawbacks. Thus, its development may not be as orderly and hierarchical as the privative software is, and may not have an appropriate funding. This may jeopardize the ease of use and coherence of the final product, increasing the transition, training and technical support costs. Besides, it must be taken into account that there is also commercial open software, as well as free privative software. In any case, the excellence of the software may be independent of such variables. Thus, the best strategy is the coexistence and free competition of all kinds of software. This will allow a quality improvement and an innovation enhancement, which will benefit the education, research, management and assistance at the university in particular and at the whole society in general.El software público libre es el fundamento del movimiento de software de fuente abierta (OSS). Éste puede facilitar el uso de estándares abiertos, con accesibilidad independiente de plataforma informática. El bajo coste o gratuidad de muchos productos OSS permite su implantación cuando los recursos económicos son escasos (países en desarrollo, escuelas, etc.). Además, su código se puede modificar, adaptar y mejorar por cualquiera, ya que es público. No obstante, el OSS también puede presentar inconvenientes. Así, su desarrollo puede no ser tan ordenado y jerárquico como el del software privativo y puede no tener una financiación apropiada. De este modo, puede verse comprometida la facilidad de uso y coherencia del producto final. Ello puede incrementar los costes de transición, entrenamiento y soporte técnico. Por otra parte, conviene recordar que existe software libre comercial y software privativo gratuito. En cualquier caso, la excelencia del software puede ser independiente de dichas variables. Por tanto, la mejor estrategia es la coexistencia y libre competencia de todo tipo de software. Así se puede conseguir una mejora de calidad y una potenciación de la innovación, que beneficie a la docencia, investigación, gestión y asistencia universitarias en particular, así como a la sociedad en general

¿Y dónde quedó el reactivo limitante? Algunas preconcepciones sobre reactivo limitante detectadas en alumnos de licenciatura

El trabajo que se presenta forma parte de un proyecto de investigación educativa cuyo énfasis se centra en conocer algunos factores importantes que interfieren la comprensión de la reacción química. En este caso abordamos las preconcepciones, sobre el reactivo limitante, de un grupo piloto de alumnos de licenciatura de la Facultad de Química (UNAM). Se presenta el análisis de las respuestas después de aplicar un cuestionario de opción múltiple, en el que se solicitaba la justificación de la opción elegida así como de las entrevistas realizadas

Factors affecting the big data adoption as a marketing tool in SMEs

The change brought by Big Data about the way to analyze the data is revolutionary. The technology related to Big Data supposes a before and after in the form of obtaining valuable information for the companies since it allows to manage a large volume of data, practically in real time and obtain a great volume of information that gives companies great competitive advantages. The objective of this work is evaluating the factors that affect the acceptance of this new technology by small and medium enterprises. To that end, the technology acceptance model called Unified Theory of Technology Adoption and Use of Technology (UTAUT) was adapted to the Big Data context to which an inhibitor was added: resistance to the use of new technologies. The structural model was assessed using Partial Least Squares (PLS) with an adequate global adjustment. Among the results, it stands out that a good infrastructure is more relevant for the use of Big Data than the difficulty of its use, accepting that it is necessary to make an effort in its implementation.Universidad Peruana de Ciencias Aplicadas, Universidad de la Costa, Fundación Universitaria Popayán, Corporación Universitaria Latinoamericana, Corporación Universitaria Reformada

AGRONOMIC EVALUATION AND CHEMICAL COMPOSITION OF AFRICAN STAR GRASS (Cynodon plectostachyus) IN THE SOUTHERN REGION OF THE STATE OF MEXICO

African Star Grass is one of the forage resources most commonly used by farmers in regions with warm-humid climates. This study was carried out to determine the nutritional and agronomic characteristics of African Star Grass (Cynodon plectostachyus) through the following variables: crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), organic matter digestibility (OMD), net forage accumulation (NFA), stem:leaf ratio, and live:dead matter ratio in the three pastures evaluated. The work took place from April 2007 to March 2008, with evaluations carried out on a monthly basis. The data were analyzed in a randomized block design in which the blocks were the pastures, and the treatments were the months of evaluation. There were no differences between the pastures evaluated for the NDF, ADF or OMD (P>0.05). Differences were found, however, in CP, while in the monthly evaluation, differences were found between the periods evaluated (P<0.05) for these variables. Differences were also found in the agronomic evaluation of pastures (P<0.05) among height of pasture, net forage accumulation (NFA), live matter, dead matter, leaf and stem, both among pastures and in the monthly evaluations. African Star Grass can therefore be considered a good choice for milk production systems in the southern region of the state of Mexico, due to its nutritional and agronomic characteristics

Biological activity of Ipomoea pauciflora Martens and Galeotti (Convolvulaceae) extracts and fractions on larvae of Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae)

Hexane, chloroform and methanol extracts of different parts of Ipomoea pauciflora were tested for their effects on the survival and development of Fall Armyworm (Spodoptera frugiperda), a Lepidoptera pest. For seven days, neonatal larvae (grown at 27 &#177; 2&#176;C with a 16: 8 (L: D) h photoperiod) were exposed to different concentrations of crude I. pauciflora extracts (ranging from 0 to 4 mg/ml) that were incorporated into an artificial diet. Surviving larvae were weighed at days 6, 9 and 13 and were maintained until moths emerged. Eleven of the 18 crude extracts showed more than 30% larval mortality. The highest mortality was produced by hexane and chloroform extracts of seeds at 4 mg/ml(96.9 and 93.8%, respectively), with LC50 values of 1.85 mg/ml and 0.54 mg/ml, respectively. Fractions of both seed extracts were isolated by gravity column chromatography over silica gel and analyzed for their active compounds. Eight fractions of the hexane extract and six fractions of the chloroform extract from I. pauciflora seeds, exhibited larvicidal effects at 1 mg/ml (mortality from 33.3 to 88.9% and from 47.2 to 77%, respectively). Changes in larval weight were observed as compared with the control group. Phytochemical analysis through GC-MS and H1 NMR revealed the presence of fatty acids and aldehydes in the active fractions. These results indicate that the bioactive extracts from the seed of I. pauciflora can induce lethal toxicity in S. frugiperda larvae or affect the weight of the surviving larvae

Aplicaciones en la región de Murcia de la información de ocupación de suelo en España (SIOSE)

Finalizadas las tareas del proyecto del Sistema de Información de Ocupación del Suelo en España (SIOSE), se plantea el aprovechamiento de la información obtenida de las múltiples bases de datos geográficas. En esta nueva fase, se ha propuesto desarrollar herramientas que faciliten la explotación de dichas bases de datos geográficas, mediante un conjunto de aplicaciones software. Además, y como un primer paso hacia la integración dentro de una infraestructura de datos espaciales (IDE) regional, ofrecer servicios basados en los estándares de publicación de información espacial en internet según el Open Geospatial Consortium (OGC), que permitan la visualización y consul- ta de los datos elaborados, con el objetivo de su difusión con el mayor grado posible.With the project completed, the information system of land use in Spain (SIOSE) takes the opportunity to use the information obtained from multiple geographic databases. In this new phase, it is proposed to develop tools that facilitate the work of these geographic databases through a set of software applications. In addition, as a first step towards integration into a regional spatial data infrastructure (SDI), providing standards-based services for spatial information published online by the Open Geospatial Consortium (OGC) which enable visualization and query the data produced with the aim of its distribution with the greatest possible degree

The effect of nutritional condition on the growth to post-flexion of bluefin tuna larvae under cultured condition

These findings indicate that protein synthesis increase in proportion to the flexion stage which is strongly associated with the development of the digestive system and therefore the increase in the nutritional condition. Ontogenetic differences in the RNA and DNA content will be discussed in more detail. Also, the pattern obtained for Atlantic bluefin tuna larva will be compared with those of other species