Search

Objetivo. Estudiar la diversidad de cicadellidae en el cultivo de maíz y determinar la efectividad de insecticidas sistémicos para prevenir el daño por achaparramiento. Materiales y métodos. El experimento se realizó en un cultivo de maíz criollo variedad Nal-Tel en Conkal, Yucatán. Se realizaron recolectas de cicadellidae mediante red de golpeo en tres sitios: plantas de maíz, bordes del cultivo y área con gramíneas adyacente al cultivo. Los ejemplares se identificación mediante claves taxonómicas por morfología. Se evaluaron cuatro tratamientos insecticidas: flonicamid, pymetrozina, ciantraniliprole y flupiradifurone en el cultivo para controlar las poblaciones de cicadellidae y prevenir daño por achaparramiento. Resultados. Se recolectaron un total de 1 556 individuos, incluidos en 37 especies de cicadellidae. Las especies con mayor abundancia relativa en las plantas de maíz fueron Empoasca sp. (22.44%), Ponana citrina (14.67%) y Dalbulus maidis (10.73%); en los bordes del cultivo fueron Hortensia similis (28.42%), Empoasca sp. (14.74%) y Ponana citrina (14.74%); en área con gramíneas adyacente al cultivo destacan Hortensia similis (49.64%), Draeculacephala soluta (35.32%), Empoasca sp. (4.63%). En las plantas de maíz, la aplicación de los insecticidas flonicamid, pymetrozina y ciantraniliprole suprimió en más del 50% la densidad poblacional de cicadellidae y entre 25-35% la incidencia de plantas con síntomas de achaparramiento del maíz. Conclusión. La diversidad de cicadellidae en el cultivo de maíz incluyó 37 especies. Los insecticidas sistémicos evaluados tuvieron efectos significativos en la supresión poblacional de cicadellidae y de la incidencia de plantas con síntomas de achaparramiento del maíz.

La familia Calliphoridae es un componente integral de la estimación del intervalo post mortem (IPM) debido a su desarrollada capacidad para detectar la descomposición de cadáveres a grandes distancias y la habilidad para colonizarlos a diferentes temperaturas en diversas áreas geográficas. Se reportan cuatro primeros registros de la familia Calliphoridae para la entomofauna de Yucatán, México: Chrysomya putoria Wiedemann, Chrysomya rufifacies Macquart, Lucilia cuprina Wiedemanny y L. sericata Meigen. Se incluye una clave de identificación e ilustraciones para las nueve especies presentes en el estado y comentarios sobre su distribución.

Background. The use of biostimulants is an alternative to improve the growth and productivity of horticultural crops. Objective. To evaluate the effect of three biostimulants (seaweed extracts, humic acids and amino acids) on the plant growth, foliar characteristics, and population density of Bemisia tabaci in habanero pepper plants (Capsicum chinense). Methodology. The biostimulants were applied to the plant growth substrate in seedling and in pot plants. The response variables were plant growth, leaf thickness and toughness, leaf area and population density of B. tabaci. Results. Humic acids promoted the number of leaves and stem thickness in seedlings. The thickness of the leaves was stimulated by seaweed extract and humic acids and the leaf area by amino acids. The biostimulants had no effect on the response of the plants to the population density of B. tabaci. Implication. The use of biostimulants in habanero pepper plants could enhance plant growth in specific growth phases. Conclusion. The use of biostimulants in habanero pepper plants did not show consistent effects on plant growth promotion in habanero pepper. There were no effects of the biostimulants on the induction of plant defense to B. tabaci in habanero pepper.

Se presenta un trabajo de diseño y construcción de un prototipo para la enseñanza de la física utilizado en una práctica de laboratorio en formación docente en la Universidad Nacional de General Sarmiento dentro de una asignatura que promueve el armado de dispositivos para la experimentación. Se detallan aspectos constructivos que pueden facilitar replicarlo bajo ciertas consideraciones. El prototipo fue armado con elementos accesibles y a través de operaciones básicas de taller. Se muestran los resultados de su implementación con un análisis técnico didáctico y de su puesta a prueba en una práctica real abordando contenidos de la física

Copyright of Agrociencia is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

IntroductionGlobal HIV infections due to HIV-1 recombinants are increasing and impede prevention and treatment efforts. Key populations suffer most new HIV infections, but their role in the spread of HIV-1 recombinants is unknown. We conducted a global analysis of the associations between key populations and HIV-1 recombinants.MethodsWe searched PubMed, EMBASE, CINAHL, and Global Health for HIV-1 subtyping studies published from 1/1/1990 to 31/12/2015. Unpublished data was collected through a global survey. We included studies with HIV-1 subtyping data of key populations collected during 1990-2015. Key populations assessed were heterosexual people (HET), men who have sex with men (MSM), people who inject drugs (PWID), vertical transmissions (VERT), commercial sex workers (CSW), and transfusion-associated infections (BLOOD). Logistic regression was used to determine associations of key populations with HIV-1 recombinants. Subgroup analyses were performed for circulating recombinant forms (CRFs), unique recombinant forms (URFs), regions, and time periods.ResultsEight hundred and eighty five datasets including 77,284 participants from 83 countries were included. Globally, PWID were associated with the greatest odds of recombinants and CRFs (OR 2.6 [95% CI 2.46–2.74] and 2.99 [2.83–3.16]), compared to HET. CSW were associated with increased odds of recombinants and URFs (1.59 [1.44–1.75] and 3.61 [3.15–4.13]). VERT and BLOOD were associated with decreased odds of recombinants (0.58 [0.54–0.63] and 0.43 [0.33–0.56]). MSM were associated with increased odds of recombinants in 2010–2015 (1.43 [1.35–1.51]). Subgroup analyses supported our main findings.DiscussionAs PWID, CSW, and MSM are associated with HIV-1 recombinants, increased preventative measures and HIV-1 molecular surveillance are crucial within these key populations.Systematic review registrationPROSPERO [CRD42017067164].

Background. The fall armyworm Spodoptera frugiperda is one of the most damaging pests of maize in tropical areas. Objective. To evaluate the damage caused by S. frugiperda and the leaf morphological traits in 15 populations of maize landrace. Methodology. The leaf damage caused by S. frugiperda and four-leaf morphological traits (leaf blade thickness, leaf blade hardness, specific leaf area and trichome density) were evaluated at 20, 30 and 40 days after emergence (DAE) in two seasons, dry (March and April) and rainy (June and July). Spearman correlation between the degree of leaf damage and each leaf morphological trait was also evaluated. Results. Maize populations showed differential response to the damage caused by S. frugiperda among seasons and evaluating date. The leaf morphological traits were different between seasons and among evaluating dates. The trichome density had intermediate negative correlation with the level of leaf damage in rainy season (rs = − 0.32, p < 0.001). Implications. The lower leaf damage may be indicator of resistance against S. frugiperda. Conclusion. The population 2020−M62 had low susceptibility to S. frugiperda, this population may be candidate for maize breeding program.

Background: Combined antiretroviral treatment (cART) for HIV infection is highly effective in controlling viral replication. However, it cannot achieve a sterilizing cure. Several strategies have been proposed to achieve a functional cure, some of them based on immune-mediated clearing of persistently infected cells. Here, we aimed at identifying factors related to CD8TC and CD4TC quality before cART initiation that associate with the persistence of CD8TC antiviral response after cART, inflammation levels, and the size of the viral reservoir. Methods: Samples from 25 persons living with HIV were obtained before and after (15 months) cART initiation. Phenotype and functionality of bulk and HIV-specific T cells were assayed by flow cytometry ex vivo or after expansion in pre-cART or post-cART samples, respectively. Cell-Associated (CA) HIV DNA (total and integrated) and RNA (unspliced [US] and multiple spliced [MS]) were quantitated by real-time PCR on post-cART samples. Post-cART plasma levels of CXCL10 (IP-10), soluble CD14 (sCD14) and soluble CD163 (sCD163) were measured by ELISA. Results: Pre-cART phenotype of CD8TCs and magnitude and phenotype of HIV-specific response correlated with the phenotype and functionality of CD8TCs post-cART. Moreover, the phenotype of the CD8TCs pre-cART correlated with markers of HIV persistence and inflammation post-cART. Finally, exhaustion and differentiation of CD4TCs pre-cART were associated with the composition of the HIV reservoir post-cART and the level of inflammation. Conclusions: Overall, this work provides data to help understand and identify parameters that could be used as markers in the development of immune-based functional HIV cure strategies.