La clase única en el aula multigrado: un reto para el maestro de Educación Primaria (Original).

The organization of the teaching-learning process through the single class as an expression of a process of appropriation of knowledge, needs sufficient pedagogical means that guarantee the orientation and preparation of the teachers, to organize the process considering the most current approaches and conceptions in the Spanish Language subject. The purpose of the work presented was to provide methodological suggestions for organizing and directing the Spanish Language class with a comprehensive approach and developer in the class group 3rd - 4th grade multigrade, contributed to solve the didactic needs of teachers of multigrade groups and their application it facilitated to elevate the quality of the class and better results were obtained in the learning of the comprehension and textual construction by the students, components checked with greater difficulty. In the research process methods, techniques and procedures were used at the theoretical, empirical and statistical level, such as analysis and synthesis, observation, documentary analysis, pedagogical tests, teacher interviews, observation of classes, making it possible to recommend methodological suggestions for the class as a valid option to apply in the different variants of the multigrade class group. These didactic suggestions with class models have been validated in rural schools in the municipality of San Luis and their validity was verified through systematic control and exchange with teachers.La organización del proceso de enseñanza aprendizaje a través de la clase única como expresión de un proceso de apropiación de conocimientos  necesita de suficientes medios pedagógicos que garanticen la orientación y preparación de los maestros, para organizar el proceso considerando los enfoques y concepciones más actuales en la asignatura Lengua Española.   El trabajo que se presenta tuvo como propósito aportar sugerencias metodológicas para organizar y dirigir la clase de Lengua Española con un enfoque integral y desarrollador en el grupo clase 3ro – 4to grado multigrado,  contribuyó a resolver necesidades didácticas de los maestros de  grupos multigrados; su aplicación facilitó elevar la calidad de la clase y se obtuvieron mejores resultados en el aprendizaje de la comprensión y construcción textual  por los alumnos, componentes comprobados con mayor dificultad. En el proceso investigativo se utilizaron métodos, técnicas y procedimientos del nivel teórico, del nivel empírico y estadístico, tales como el análisis y síntesis,  la observación, el análisis documental, prueba pedagógica, entrevista a maestros y observación a clases,  posibilitando recomendar las sugerencias metodológicas para la clase como una opción válida a aplicar en las variantes del grupo clase multigrado. Estas sugerencias didácticas con modelos de clases han sido validadas en escuelas rurales del municipio de San Luis  y se constató su validez mediante el control y el intercambio sistemático con los maestros.&nbsp

Response to a Salmonella Typhimurium challenge in piglets supplemented with protected sodium butyrate or Bacillus licheniformis : effects on performance, intestinal health and behavior

Salmonella spp. is one of the worldwide leading causes of food-borne illnesses for which the inclusion of probiotics or organic acids in animal feeds can be useful control methods. Experimental models are utilized to test the efficacy of strategies against pathogens, but they exhibit limitations which may preclude finding sensible evaluation parameters. The objective of this work is to evaluate the efficacy of 2 different feed additives; a Bacillus licheniformis based probiotic and a protected sodium butyrate (SB) salt, using an experimental model of salmonellosis and, second, to explore if behavior analysis can be used as a sensible evaluation tool for additives evaluation. A total of 78 piglets weaned at 24 d, 8.3 kg BW, were used. Seventy-two were placed in 3 rooms of 8 pens (3 animals/pen) with evenly distributed treatments (n = 8): CON, control group with plain diet; PRO, plain diet with 1 kg/t of Proporc (10 9 cfu of B. licheniformis /kg of feed), and BUT, plain diet with 3 kg/t of Gustor BP70 (2.1 g of partially protected SB salt/kg of feed). Remaining piglets (n = 6) were separated and used as a challenge negative control. The experiment lasted 16 d. After 1 wk of adaptation, animals were challenged with 5 × 10 8 cfu of Salmonella Typhimurium. One pig per pen was euthanized and sampled at d 4 and 8 post-inoculation (PI). There were no significant differences among treatments for ADFI, ADG, G:F, rectal temperature, fecal consistency, pH, ammonia, short-chain fatty acids and lactic acid concentrations, cytokine TNF-α, Pig-MAP acute-phase proteins and histological parameters. However, both products were equally able to reduce colonization and shedding of Salmonella (P = 0.016 for PRO and BUT vs. CON). In addition, PRO treatment had a positive effect on behavioral displays, particularly exploring (P < 0.05 vs. CON), feeding (P < 0.05 vs. CON and BUT) and other active behaviors (P < 0.05 vs. CON and BUT) in the morning period (0830 to 1030 h). In the afternoon (1400 to 1600 h), the challenge effect was most significant. Pigs were less active after the challenge (P < 0.001), with a decrease in positive contacts (P = 0.004), exploration (P < 0.001) and feeding behaviors (P < 0.001) on d 3 PI, in comparison with before the challenge. Accordingly, many lying conducts increased at d 3 PI (P < 0.05). In conclusion, both treatments had positive effects against Salmonella, and behavior analysis appears to be a sensible tool to be considered

Prebiotic and probiotic agents enhance antibody-based immune responses to Salmonella Typhimurium infection in pigs

Salmonellosis causes significant economic losses to the pig industry and contaminated pork products are an important source of Salmonella for humans. The EU ban on the use of antibiotic growth promoters in pig production, and the emergence of antibiotic resistance has meant there is a pressing need for alternative control strategies for pathogenic bacteria such as S. Typhimurium in pigs. Here, we determined the effects of prebiotic, probiotic and synbiotic diet regimes on antibody responses to oral Salmonella challenge of pigs. The data demonstrate that the inclusion of the probiotic Lactobacillus plantarum B2984 in the diet of piglets (∼1 × 1010 cfu/animal/day) enhanced serum IgM (P<0.001), IgG (P=0.001) and IgA (P=0.039) responses to S. Typhimurium infection including cross-reacting antibodies to S. Enteritidis. Similarly, inclusion of the prebiotic lactulose at 1% (w/w) of the feed on a daily basis in the diet enhanced serum IgM (P=0.010), IgG (P=0.004) and IgA (P=0.046) responses to S. Typhimurium infection and also cross-reacting antibodies to S. Enteritidis. Inclusion of both additives in the synbiotic diet also elicited an enhanced immune response with IgM (P=0.009) and IgG (P=0.046) levels being increased, however a significant interaction of the pre and probiotics was observed when considering the immune responses to S. Typhimurium (IgM P=0.004; IgG and IgA, P<0.001 for interaction). With respect to immune responses, the effects of pre or probiotic administration were the same or reduced in the synbiotic diet compared to when used in isolation. The data support the use of Lactobacillus plantarum B2984 or lactulose as strategies to contribute to the protection of weaned piglets from zoonotic bacterial pathogens, but caution must be taken when combining dietary supplements as combinations can interact

Congenital heart defects in human fetuses with extra cardiac defects

Introducción: las malformaciones cardiacas son los defectos congénitos más frecuentes en los seres humanos. Estas son alteraciones estructurales y funcionales del corazón, del sistema circulatorio y de los grandes vasos, que se desarrollan durante la embriogénesis cardiaca. Estos defectos repercuten en la calidad de vida de los pacientes y familiares, conocer mejor estos defectos permite su prevención, diagnóstico y tratamiento.Objetivo: identificar la asociación entre las cardiopatías congénitas y los defectos extra cardiacos, en fetos humanos.Métodos: se realizó una investigación observacional analítica y transversal en fetos humanos obtenidos a partir de interrupciones de embarazo realizadas por indicación de Genética Médica entre enero del 2019 y mayo del 2020 en Pinar del Río, Cuba. La muestra estuvo representada por 42 fetos, seleccionados a través de un muestreo no probabilístico de tipo intencional. La información se obtuvo de los informes de autopsias y las solicitudes de interrupción, a los datos obtenidos se les aplicaron estadística descriptiva e inferencial.Resultados: en el estudio se observó que la mayor parte de los fetos estudiados eran del sexo masculino; la comunicación interventricular fue el defecto cardiovascular más frecuente y que entre los defectos extra cardiacos, los de mayor incidencia fueron los del sistema Osteomioarticular, mostrando estos defectos una asociación significativa a la Comunicación interventricular. Conclusiones: en los fetos humanos, los defectos del sistema osteomioarticular se asocian a malformaciones cardiovasculares específicas.Introduction: cardiac malformations are the most frequent congenital defects in humans. These are structural and functional alterations of the heart, circulatory system and great vessels that develop during cardiac embryogenesis. These defects have an impact on the quality of life of patients and their families, and a better understanding of these defects allows their prevention, diagnosis and treatment.Objective: to identify the association between congenital heart disease and extracardiac defects in human fetuses.Methods: an analytical and cross-sectional observational research was carried out in human fetuses obtained from pregnancy terminations performed by indication of Medical Genetics between January 2019 and May 2020 in Pinar del Rio, Cuba. The sample was represented by 42 fetuses, selected through a non-probabilistic purposive sampling. The information was obtained from autopsy reports and requests for termination. Descriptive and inferential statistics were applied to the data obtained.Results: the study showed that most of the fetuses studied were male; ventricular septal defect was the most frequent cardiovascular defect and that among the extracardiac defects, those with the highest incidence were those of the osteomyoarticular system, showing a significant association with ventricular septal defect.Conclusions: in human fetuses, osteomyoarticular system defects are associated with specific cardiovascular malformations

CÉLULAS DENDRÍTICAS EN LA INMUNOPATOLOGÍA DEL VIRUS DE INMUNODEFICIENCIA HUMANA

En México, como en el resto de los países del mundo, el SIDA ha sido considerado como un serio problema de salud pública. El VIH-1 tiene la capacidad de infectar diversos tipos celulares: células T, macrófagos y células dendríticas (CD). Estas últimas, son cruciales en la defensa contra agentes infecciosos y juegan un papel importante en la patogénesis del virus, constituyen una de las primeras células en ser infectadas en mucosa periférica y están distribuidas en vagina,ectocervix y mucosa anal; permitiendo así el contacto con el VIH-1 durante la exposición sexual.Recientemente se ha demostrado que una proteína de membrana tipo II denominada DC-SIGN, participa en la unión del VIH-1 a las CD. Este receptor, es el responsable de mediar la infección a las células T a través de CD, utilizandolas como portadoras permitiendo que el virus tenga acceso a tejido linfático, su mayor sitio de replicación, contribuyendo de esta manera a la patogénesis del VIH/SIDA.Palabras clave: SIDA, VIH, Células dendríticas   AIDS, HIV, dendrtitic cel

DIVERSIDAD GENÉTICA DEL VIRUS DE INMUNODEFICIENCIA

El Síndrome de Inmunodeficiencia Adquirida (SIDA), es considerado como una pandemia que al igual que otras enfermedades requiere del diagnóstico, vigilancia y tratamiento efectivos. En México como en el resto de los países del mundo, el SIDA es considerado como un serio problema de salud pública, ya que a pesar de todos los esfuerzos que se han hecho para difundir los conocimientos de los aspectos epidemiológicos, de diagnóstico, tratamiento y prevención, el número de casos reales es mayor que el informado por las autoridades; por lo tanto, las consecuencias socioeconómicas son mucho más graves. El VIH-1, es un virus que experimenta una alta variación genética, ésta, causa cambios en el tropismo, virulencia y transmisión de la infección. Nuevas variantes y/o subtipos del VIH-1 se encuentran circulando con un amplio rango de propiedades de virulencia y transmisión que están surgiendo y dispersándose alrededor del mundo en una forma alarmante. El VIH-1 predominante en México es el subtipo B, pero esto no excluye la presencia de otros subtipos en el país, como es la presencia del Subtipo C detectado en un individuo sudafricano. Una adecuada vigilancia epidemiológica del VIH/SIDA incluyendo la identificación, caracterización y análisis de los subtipos predominantes en nuestro país deben ser llevadas a cabo en un esfuerzo para evaluar su diversidad genética y comprender mejor la problemática sobre su diseminación, definir los patrones de distribución geográfica, su epidemiología, sobre el desarrollo de antivirales y sobre todo el diseño de vacunas.Palabras clave: SIDA, VIH, subtipos y formas recombinantes circulantes (FRC).        AIDS, HIV, subtypes and Circulating Recombinant Forms(CRF

Effect of dietary vitamin D3 and 25-hydroxyvitamin D3 supplementation on plasma and milk 25-hydroxyvitamin D3 concentration in dairy cows

Milk enriched with vitamin D by supplementing dairy cow diets could provide a valuable dietary source of vitamin D, but information on the feasibility of this approach is limited. In the current study, the effects of supplementing dairy cows with either vitamin D3 or 25(OH) D3 over the transition/early lactation period on plasma and milk vitamin D concentrations were compared. Sixty dairy cows were randomly allocated to one of four dietary treatments from 14 days pre-calving to 56 days post-calving. Treatments were a control diet (Control) for both pre-calving and post-calving periods containing 0.625 mg/day vitamin D3; a pre-calving diet supplemented with 6 mg 25(OH) D3/day, but with a post-calving diet matching that of the control diet (25(OH) D3 pre-calving); the control diet pre-calving but with the post-calving diet supplemented with 2 mg vitamin D3/day (D3max), and the control diet pre-calving but with the post-calving diet supplemented with 1.5 mg 25(OH) D3/day (25(OH) D3 post-calving). No treatment effect on milk yield, composition or 25(OH) D3 concentration was observed. However there was an interaction of treatment and time for plasma 25(OH) D3 concentration; this increased within two weeks of supplementation for the 25(OH) D3 pre-calving treatment (peaking just after calving, 202 ng/ml), whereas that of the 25(OH) D3 post-calving group had a slower response following supplementation, continuing to increase at 56 days. There were correlations between plasma and milk 25(OH) D3 concentrations at days 4 and 14 of lactation, but not at later sampling times. The D3max treatment did not increase 25(OH) D3 concentration in plasma or milk. Overall, results from this study indicate that supplemental 25(OH) D3 is an effective means of enhancing dairy cow plasma 25(OH) D3 concentrations compared with vitamin D3 supplementation, but not necessarily milk concentrations

Optimization of Pathogenicity Tests for Selection of Native Isolates of Entomopathogenic Fungi Isolated from Citrusgrowing Areas of México on Adults ofDiaphorina citriKuwayama (Hemiptera: Liviidae)

Huanglonbing (HLB), es considerado una de las más letales enfermedades de los cítricos alrededor del mundo, y ha alcanzado las principales áreas de producción de limón Mexicano (Citrus latifolia Tanaka) en la costa del pacifico de México. Los productores han iniciado el uso de insecticidas para controlar las poblaciones del psílido asiático de los cítricos, Diaphorina citri Kuwayama (Hemiptera: Liviidae), el vector del patógeno ‘Candidatus Liberibacter asiaticus’ asociado con el HLB. Actualmente los costos de los insecticidas y los efectos secundarios de su uso son las principales preocupaciones, ya que podrían perjudicar la estrategia de manejo contra el vector; y por lo tanto, alternativas ecológicas y económicamente viables a los insecticidas convencionales serian necesarias a corto plazo. Por tanto, el objetivo de este estudio fue evaluar la patogenicidad de 27 aislados nativos y 3 cepas de hongos entomopatógenos para determinar su potencial como agentes de control biológico sobre Diaphorina citri usando 2 diferentes métodos de bioensayo. Los bioensayos fueron realizados bajo condiciones de laboratorio (26 ± 2 °C, 60 ± 5% H.R y 16:8 h L:O) mediante la exposición de insectos adultos a una concentración de 1 × 108 conidios por mililitro utilizando 2 diferentes métodos de aplicación, es decir, por asperjado de esporas en las plántulas de cítricos y por asperjado directo a los psílidos adultos. Los resultados mostraron que para el asperjado directo a los adultos los aislados HIB-24 (B. bassiana) y HIB-32 (I. fumosorosea) mostraron el mayor porcentaje de mortalidad (60.66%). Respecto al asperjado de plántulas el aislado HIB-19 (I. fumosorosea) mostró el mayor porcentaje de mortalidad (62.02%). Los resultados de este estudio demuestran el potencial para el uso de hongos entomopatógenos en el manejo de D. citri en México. ABSTRACT Huanglongbing (HLB), considered one of the most lethal diseases of citrus worldwide, has reached the main areas of Mexican lime (Citrus latifolia Tanaka) fruit production on the Pacific coast of México. Growers have initiated intensive use of insecticides in order to control populations of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), the vector of the pathogen, ‘Candidatus Liberibacter asiaticus’ associated with huanglongbing. Presently, costs of insecticides and the side effects of their use are major concerns, because they could impair the management strategy against the vector; and thus, ecologically and economically viable alternatives to conventional insecticides are required in the short term. Therefore the goal of this study was to evaluate the pathogenicity of 27 native isolates and 3 strains of entomopathogenic fungi and determine their potential as biological control agents of D. citri by using 2 different bioassay methods. Bioassays were performed under laboratory conditions (26 ± 2 °C, 60 ± 5% RH and 16:8 h L:D) by exposing adult insects to a concentration of 1 × 108 conidia per milliliter using 2 different application methods, i.e., spraying the spores onto the citrus seedlings and spraying the spores directly onto the adult psyllids. The results showed that by direct spraying the adults, HIB-24 (B. bassiana) and HIB-32 (I. fumosorosea) isolates showed the highest mortality (60.66%). Regarding spraying of the seedlings, HIB-19 (I. fumosorosea) showed the highest percentage of mortality (62.02%). The results from this study demonstrate potential for using entomopathogenic fungi in the management of D. citri in México