Evaluación de técnicas de tinción para la observación de bandas de crecimiento en vértebras de elasmobranquios tropicales

The aim of this study was to assess the suitability of different vertebrae staining techniques for the visualization and counting of growth bands in tropical species of batoids (Narcine leoparda, Urotrygon aspidura, Hypanus longus, Potamotrygon magdalenae) and sharks (Alopias pelagicus, Carcharhinus falciformis, Sphyrna lewini, Sphyrna corona and Mustelus lunulatus). Different cutting thicknesses and staining protocols were tested, analysing the precision and bias of each combination to identify the most accurate technique for estimating age. Vertebral sections of 0.4 mm were more suitable for batoids, except for Narcine leoparda; for this species and for all the shark species assessed, sections of 0.5 mm are recommended. Different combinations of stain and exposure time were required to achieve the best visualizations of vertebral growth band pair for the shark and ray species. Intraspecific variation occurred among vertebrae size of batoids. Our results confirm the importance of defining a suitable species-specific protocol for sectioning and staining hard structures before carrying out an age and growth study to improve the reliability of the age estimates.El objetivo de este estudio fue evaluar la efectividad de diferentes técnicas de tinción de vértebras en la visualización y el conteo de bandas de crecimiento en especies tropicales de batoideos (Narcine leoparda, Urotrygon aspidura, Hypanus longus, Potamotrygon magdalenae) y tiburones (Alopias pelagicus, Carcharhinus falciformis, Sphyrna lewini, Sphyrna corona y Mustelus lunulatus). Se probaron diferentes espesores de corte y protocolos de tinción, analizando la precisión y el sesgo de cada combinación para identificar la técnica más precisa para estimar la edad. Las secciones vertebrales de 0,4 mm fueron más adecuadas para batoideos, excepto para Narcine leoparda; para esta especie y para todas las especies de tiburones evaluadas, se recomiendan secciones de 0,5 mm. Se identificaron diferentes combinaciones de tinción y tiempo de exposición para lograr las mejores visualizaciones de las bandas de crecimiento vertebral en las especies de tiburones y rayas. En los batoideos se identificó variación intraespecífica de acuerdo con el tamaño de las vértebras. Nuestros resultados confirman la importancia de definir un protocolo especie-específico adecuado para cortar y teñir las estructuras duras antes de realizar un estudio de edad y crecimiento y así incrementar la confiabilidad de las estimaciones de edad

Efectos De Un Compensador Serie Síncrono Estático (Sssc) En Un Sistema De Potencia

En este artículo se muestran los efectos de compensación de un SSSC instalado en un sistema de potencia para el estudio de estabilidad de pequeña señal. El sistema es modelado incluyendo el efecto del compensador serie, como también el modelo de una máquina síncrona conectada a un barraje infinito (SMIB, single machine infinite bus power system) a través de una línea de transmisión. Se muestran los resultados de los modelos lineal y no lineal para diferentes perturbaciones obtenidos a través de simulación en el Matlab

Use of elicitors as an approach for sustainable agriculture

Plant pathogens are responsible for large declines in agricultural production. Their control is carried out mainly by chemical and frequently proposed biological methods to reduce their environmental impact. On the other hand, plant-pathogen or microbe interactions generate multiple signals within plants activating defense mechanism, some of which can also be induced by elicitors (protective molecules). Elicitor-induced plant signaling serves as a guide to a series of intracellular events that end in activation of transduction cascades and hormonal pathways triggering induced resistance (IR) and consequently activation of plant immunity to environmental stresses. So, it is necessary to understand where and how elicitors act in cellular defense mechanism of crops, to improve protection and management for sustainable crop. Therefore this review focused on main topics that guide induced resistance and therefore activation of plant immune response.Keywords: Elicitors, defense mechanism, Immune response, Induced resistance, MAP

Reproducción experimental de cromatosis en conejos por medio del suministro de la planta mamei-tomatillo (Bunchosia pseudomitida).

Se realizaron dos experimentos que consistieron en el suministro de 5 a 20 gr diarios de la planta mamei-tomatillo o pateperro (Bunchosia pseudonitida) a 15 conejos con el fín de conocer los efectos que aquella puediera tener sobre éstos y establecer una posible relación con la cromatosis en bovinos y ovinos de los departamentos del Huila y Tolima(Colombia). Los conejos presentaron síntomas, signos y lesiones similares a los observados en casos de ocurrencia natural de Cromatosis tales como pigmentación rosada de los dientes y eliminación de orina pigmentada luego de consumo diario de 15 gr de planta verde por un período de 10 a 15 días. En animales con consumo mayor de 9 gr por período de 60 días, se observó pigmentación rosada en tejidos subcutáneos, fascias, superficies de músculos y órganos que tuviesen tejido elástico, además se estableció un retardo en el incremento de peso en los grupos de conejos que consumieron mayor cantidad de la planta en experimentación. Por los resultados obtenidos se deduce que la planta mamei-tomatillo o pateperro (Bunchosia pseudonitida) está directamente relacionada con la entidad patológica conocida como Cromatosis o vaca moradaCunicultura-Conejo (oryctolagus) - Oryctolagus Cuniculo

Incidence of complications in breast reconstruction with autologous tissue in a third level hospital

Background: The objective of this study is to analyze the incidence of complications after breast reconstruction with pedicled or free flaps at the hospital general de Mexico "Dr. Eduardo Liceaga”. Methods: A retrospective, single-center study, including 44 female patients, who underwent immediate or delayed breast reconstruction after breast cancer, between 2019 and 2020, and had at least a 2-year follow up, evaluating the association between patient risk factors (age, history of radiotherapy, presence of overweight or obesity and immediate or delayed reconstruction) with the presence of complications such as seroma, hematoma, wound infection or wound dehiscence. We analyzed data with SPSS software, v23.0. Results: There was no statistically significant difference for the presence of complications associated with risk factors studied. Conclusions: We need more prospective, multicenter studies, including larger sample and strict follow up of patients

Descriptive analysis of histological types in women undergoing post mastectomy breast reconstruction

Background: Breast cancer is a pathological entity that widely compromises the life and quality of life of affected women; in addition to the great affectation to the current health services. Therefore, maintaining an accurate and complete cancer registry program is one of the most important factors in implementing national cancer control programs and evaluating the results of screening, diagnosis, and treatment. Among the current limitations in the studies, there is a gap in the study of the population undergoing breast reconstruction. Methods: A retrospective study was carried out at hospital general de México “Dr. Eduardo Licéaga” with the information from the clinical records of the period 2019-2020. Patients undergoing breast reconstruction after mastectomy with histological report were included. Through non-probabilistic sampling, a population of 138 women was formed. For data analysis, frequencies and percentages were calculated for the qualitative variables; while for the quantitative variables, mean and standard deviation were calculated. Results: 138 women who underwent breast reconstruction were included, the mean age was 49.9±10.85 years, the mean BMI was 26.80±4.62 kg/m2, the secondary educational level predominated (34.8%), radiotherapy was applied to 34.1%, reconstruction was late in 75.4%, the most frequent reconstruction technique was TRAM flap (44.2%), the histological type of invasive ductal carcinoma predominated (68.1%). Conclusions: In women undergoing post-mastectomy breast reconstruction, the histological type of invasive ductal carcinoma predominates.

Analogies between geminivirus and oncovirus: Cell cycle regulation

Geminiviruses are a large family of plant viruses whose genome is composed of one or two circular and single strand of DNA. They replicate in the cell nucleus being Rep protein, the only viral protein necessary for their replication process. Geminiviruses as same as animal DNA oncoviruses, like SV40, adenovirus and papillomavirus, use the host replication machinery to replicate their DNA. Consequently, they alter host cell cycle regulation to create a suitable environment for their replication. One of the events involved in this alteration would be the inactivation of the retinoblastoma protein (pRb) that negatively regulates the G1/S transition in cells. The discovery of one homologue of the pRb in plants and the finding that Rep protein of some geminiviruses interacts with human retinoblastoma protein, as well as animal virus oncoproteins, is very interesting. This finding laid the groundwork for subsequent detection of analogies between geminiviruses and animal DNA tumor viruses, especially in their interaction with pRb. Moreover, the finding allowed the determination of how this interaction affects the regulation of the cell cycle in plants and animals. Accumulated knowledge generates new interesting questions and possible implications, and so, in this document, we dare to watch in that direction.Key words: Geminivirus, oncovirus, retinoblastoma protein, cell cycle regulation, endoreduplication

Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.

BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography

Evaluation of Moringa oleífera in the water treatment with high turbidity and organic

[ES] El presente trabajo evalúa la eficiencia del uso de la Moringa oleífera (M.O) como coagulante en el tratamiento de aguas de alta turbidez y carga orgánica. Inicialmente los resultados demostraron que el coagulante a base de las semillas de M.O pre-tratada con cloruro de sodio (NaCl 1.0 N) y usando una dosis de 0.74 g/L, alcanza remociones de 87.3% y 88.8% para turbidez y sólidos suspendidos totales (SST), asimismo valores de 25.9% y 26.3% para DBO5 y DQO respectivamente. En una segunda etapa, el coagulante, sometido a extracción Soxhlet y dosis de 0.5 g/L, muestran máximas eficiencia de 97.8%, 89.99%, 51.4% y 35.3% en la remoción de turbidez, SST, DQO y DBO5. Las más altas eficiencias obtenidas fueron alcanzadas mediante la previa extracción de aceites, grasas y otros componentes de la semilla de M.O. Estudios relacionados al reaprovechamiento de sub-productos de la extracción deben ser realizados.[EN] In this study, the removal efficiency of Moringa Oleifera (M.O) seed as coagulant in the treatment of highly loaded wastewater in terms of turbidity and organic matter was evaluated. Initially the results showed removals of 87.3% and 88.8% for turbidity and total suspended solids (TSS) and 25.9% and 26.3% for BOD5 and COD respectively, when the seeds of M.O were pre-treated with sodium chloride (NaCl 1.0 N) and used as coagulant at a dose of 0.74 g/L. In a second stage, the natural coagulants previously subjected to Soxhlet extraction were compared, the results showed maximum efficiency with 0.5 g/L of the seed of M.O, with values of 97.8%, 9.99%, 51.4% and 35.3% in the removal of turbidity, TSS, COD and BOD5, respectively. The highest efficiencies were achieved through the prior extraction of oils, fats and other components of the M.O seed. Studies related to the reuse of extraction by-products should be performed.Mejía Carrillo, PW.; Urquia Collantes, K.; Cabello Torres, RJ.; Valdiviezo Gonzales, LG. (2020). Evaluación de la Moringa oleifera en el tratamiento de aguas con alta turbidez y carga orgánica. Ingeniería del agua. 24(2):119-127. https://doi.org/10.4995/ia.2020.12274OJS119127242Adinolfi, M., Corsaro, M. M., Lanzetta, R., Parrilli, M., Folkard, G., Grant, W., Sutherland, J. 1994. Composition of the coagulant polysaccharide fraction from Strychnos potatorum seeds. Carbohydrate research, 263(1), 103-110. https://doi.org/10.1016/0008-6215(94)00149-9Amran, A., Syamimi Zaidi, N., Muda, K., Wai Loan, L. 2018. Effectiveness of Natural Coagulant in Coagulation Process: A Review. International Journal of Engineering & Technology, 7(3.9), 34. https://doi.org/10.14419/ijet.v7i3.9.15269Bongiovani, M. C., Camacho, F. P., Nishi, L., Coldebella, P. F., Valverde, K. C., Vieira, A. M., Bergamasco, R. 2014. Improvement of the coagulation/flocculation process using a combination of Moringa oleifera lam with anionic polymer in water treatment. Environmental Technology. 35(17), 2227-2236. https://doi.org/10.1080/09593330.2014.899398Camacho, F. P., Sousa, V. S., Bergamasco, R., Teixeira, M. R. 2017. The use of Moringa oleifera as a natural coagulant in surface water treatment. Chemical Engineering Journal. 313(1), 226-237. https://doi.org/10.1016/j.cej.2016.12.031Crapper, D. R., Krishnan, S. S., Dalton, A. J. 1973. Brain aluminum distribution in Alzheimer's disease and experimental neurofibrillary degeneration. Science, 180(4085), 511-513. https://doi.org/10.1126/science.180.4085.511Eman, N. A., Tan, C. S., Makky, E. A. 2014. Impact of Moringa oleifera Cake Residue Application on Waste Water Treatment: A Case Study. Journal of Water Resource and Protection, 6(7), 677-687. https://doi.org/10.4236/jwarp.2014.67065Fersi, C., Gamra, B., Bozrati, H., Gorgi, C., Irmani, A. 2018. Characterizing the performance of coagulation-flocculation using natural coagulants as pretreatment of tannery wastewater. Journal of Materials and Environmental Sciences, 9(8), 2379-2386. Obtenido de https://www.jmaterenvironsci.com/Document/vol9/vol9_N8/262-JMES-4022-Fersi.pdfFreitas, T. K. F. S., Almeida, C. A., Manholer, D. D., Geraldino, H. C. L., De Sousa, M. T. F., Garcia, J. C. 2018. Review of Utilization Plant-Based Coagulants as Alternatives to Textile Wastewater Treatment. In: Textile Science and Clothing Technology (MUTHU, S. ed.) Detox Fashion, Springer, Singapore, 27-47. https://doi.org/10.1007/978-981-10-4780-0_2Garcia-Fayos, B., Arnal, J.M.., Sancho, M., Rodrigo, I. 2016. Moringa oleifera for drinking water treatment: influence of the solvent and method used in oilextraction on the coagulant efficiency of the seed extract. Desalination and water treatment, 57(48-49), 23397-23404. https://doi.org/10.1080/19443994.2015.1137144Keogh, M. B., Elmusharaf, K., Borde, P., McGuigan, K.G. 2017. Evaluation of the natural coagulant Moringa oleifera as a pretreatment for SODIS in contaminated turbid water. Solar Energy, 158, 448-454. https://doi.org/10.1016/j.solener.2017.10.010Kristianto, H. (2017). The Potency of Indonesia Native Plants as Natural Coagulant: a Mini Review. Water Conservation Science and Engineering, 2(2), 51-60. https://doi.org/10.1007/s41101-017-0024-4Kumar, V., Othman, N., Asharuddin, S. 2017. Applications of Natural Coagulants to Treat Wastewater − A Review. MATEC web conferences, 103(06016), 1-9. https://doi.org/10.1051/matecconf/201710306016Kwaambwa, H. M., Rennie, A. R. 2011. Interactions of surfactants with a water treatment protein from Moringa oleifera seeds in solution studied by zeta-potential and light scattering measurements. Biopolymers, 97(4), 209-218. https://doi.org/10.1002/bip.22014Lee, C. S., Robinson, J., Chong, M. F. 2014. A review on application of flocculants in wastewater treatment. Process Safety and Environmental Protection, 92, 489-508. https://doi.org/10.1016/j.psep.2014.04.010Lédo, P. G., Lima, R. F., Paulo, J. B., Duarte, M. A. 2009. Estudio Comparativo de Sulfato de Aluminio y Semillas de Moringa oleifera para la Depuración de Aguas con Baja Turbiedad. Información Tecnológica, 20(5), 3-12. https://doi.org/10.4067/S0718-07642009000500002Liew, A. G., Noor, J. M., Muyibi, S.A., Fugara, A. M., Muhammed, T. A., Iyuke, S. E. 2006. Surface water clarification using M. oleifera seeds. International Journal of Environmental Studies, 63(2), 211-219. https://doi.org/10.1080/00207230500117670Macías, M. R., Domínguez, Y. D., Y., Muñoz, S.R., Alvarez, B.G., B., Santana E, F., García, D.T. 2017. Empleo de semillas de Moringa oleifera en el tratamiento de residuales líquidos. Ingeniería Hidráulica y Ambiental, 38(2), 87-101. Obtenido de http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S1680-03382017000200007&lng=es&tlng=es.Matilainen, A., Vepsäläinen, M., Sillanpää, M. 2010. Natural organic matter removal by coagulation during drinking water treatment: a review. Advances in Colloid and Interface Science, 159(2), 189-197. https://doi.org/10.1016/j.cis.2010.06.007MVCS. 2006. Reglamento Nacional de edificaciones, DS N° 011-2006- VIVIENDA: Ministerio de Vivienda Construcción y Saneamiento. Obtenido de http://www3.vivienda.gob.pe/Direcciones/Documentos/RNE_Actualizado_Solo_Saneamiento.pdfNdabigengesere, A., Narasiah, K. S. 1998. Quality of Water Treated by Coagulation Using Moringa oleifera Seeds. Water Research: 32(3), 781-791. https://doi.org/10.1016/S0043-1354(97)00295-9Nkurunziza, T., Nduwayezu, J. B., Banadda, E. N., Nhapi, I. 2009. The effect of turbidity levels and Moringa oleifera concentration on the effectiveness of coagulation in water treatment. Water Science & Technology, 59(8), 1551-1558. https://doi.org/10.2166/wst.2009.155Okuda, T., Baes, A. U., Nishijima, W., Okada, M. 1999. Improvement of extraction method of coagulation active components from Moringa oleifera seed. Water Research, 33(15), 3373-3378. https://doi.org/10.1016/S0043-1354(99)00046-9Petersen, H. H., Petersen, T. B., Enemark, H. L., Olsen, A., Dalsgaard, A. 2016. Removal of Cryptosporidium parvum oocysts in low quality water using Moringa oleifera seed extract as coagulant. Food and Waterborne Parasitology, 3, 1-8. https://doi.org/10.1016/j.fawpar.2016.03.002Pritchard, M., Craven, T., Mkandawire, T., Edmondson, A. S., O'neill, J. G. 2010. A comparison between Moringa oleifera and chemical coagulants in the purification of drinking water - An alternative sustainable solution for developing countries. Physics and Chemistry of the Earth, Parts A/B/C, 35(13-14), 798-805. https://doi.org/10.1016/j.pce.2010.07.014Sengul, A. B., Ersan, G., Tufekci, N. 2018. Removal of intra and extracellular microcystin by submerged ultrafiltration (UF) membrane combined with coagulation/flocculation and powdered activated carbon (PAC) adsorption. Journal of Hazard Materials. 343, 29-35, https://doi.org/10.1016/j.jhazmat.2017.09.018SUNASS. 2008. Estudio Diagnostico situacional de los sistemas de tratamiento de aguas residuales en las EPS del Perú y Propuestas de solución: Superintendencia Nacional de Servicios de Saneamiento. Obtenido de https://www.sunass.gob.pe/doc/Publicaciones/libro_ptar_gtz_sunass.pdfSUNASS. 2015. Diagnóstico de las plantas de tratamiento de aguas residuales en el ámbito de operación de las entidades prestadoras de servicios de saneamiento: Superintendencia Nacional de Servicios de Saneamiento Obtenido de https://www.sunass.gob.pe/doc/Publicaciones/libro_ptar_gtz_sunass.pdfChoumane, F.Z., Benguella, B., Maachou, B., Saadi, N. 2017. Valorisation of a bioflocculant and hydroxyapatites as coagulationflocculation adjuvants in wastewater treatment of the steppe in the wilaya of Saida (Algeria). Ecological Engineering, 107, 152-159. https://doi.org/10.1016/j.ecoleng.2017.07.01

Nondense mammographic area and risk of breast cancer

Introduction The mechanisms underlying the strong association between percentage dense area on a mammogram and the risk of breast cancer are unknown. We investigated separately the absolute dense area and the absolute nondense area on mammograms in relation to breast cancer risk. Methods We conducted a nested case-control study on prediagnostic mammographic density measurements and risk of breast cancer in the Nurses\u27 Health Study and the Nurses\u27 Health Study II. Premenopausal mammograms were available from 464 cases and 998 controls, and postmenopausal mammograms were available from 960 cases and 1,662 controls. We used a computer-assisted thresholding technique to measure mammographic density, and we used unconditional logistic regression to calculate OR and 95% CI data. Results Higher absolute dense area was associated with a greater risk of breast cancer among premenopausal women (ORtertile 3 vs 1 = 2.01, 95% CI = 1.45 to 2.77) and among postmenopausal women (ORquintile 5 vs 1 = 2.19, 95% CI = 1.65 to 2.89). However, increasing absolute nondense area was associated with a decreased risk of breast cancer among premenopausal women (ORtertile 3 vs 1 = 0.51, 95% CI = 0.36 to 0.72) and among postmenopausal women (ORquintile 5 vs 1 = 0.46, 95% CI = 0.34 to 0.62). These associations changed minimally when we included both absolute dense area and absolute nondense area in the same statistical model. As expected, the percentage dense area was the strongest risk factor for breast cancer in both groups. Conclusions Our results indicate that absolute dense area is independently and positively associated with breast cancer risk, whereas absolute nondense area is independently and inversely associated with breast cancer risk. Since adipose tissue is radiographically nondense, these results suggest that adipose breast tissue may have a protective role in breast carcinogenesis