Abstract Microbial adaptations to extreme environments can lead to biotechnological applications. This study aimed to evaluate the resistance of Antarctic Cladosporium to adverse conditions (temperature, salinity, UV radiation, and nutrients) and refine their taxonomy. Sequencing and phylogenetic analysis using ITS-act markers resulted in a more accurate taxonomic identification, revealing the presence of five different species, belonging to the complexes C. cladosporioides and C. sphaerospermum. The growth at different temperatures indicates that the soil isolates LAMAI 564 and 1800 (phylogenetically closely related) and LAMAI 2541 are psychrophilic, while the other isolates are psychrotolerant. The fungi isolated from the saline samples LAMAI 595, 616, and 1369 showed better growth results at higher salinity (15%). The fungi most resistant to UV radiation were isolated from terrestrial and marine samples (LAMAI 595, 616, 1800, and 564). LAMAI 595 and 616 (phylogenetically closely related and isolated from the same kind of sample) showed the capacity of nutritional versatility, growing well in both rich and poor-nutrient media. The fungus LAMAI 595 was the most promising for biotechnological application, exceeding the other isolates in the harsh conditions studied. The resistance of the Antarctic Cladosporium to adverse conditions opens new perspectives in the field of applied microbiology of extremophiles. applications temperature, temperature (temperature nutrients taxonomy ITSact ITS act identification species C sphaerospermum 56 180 phylogenetically 254 psychrophilic psychrotolerant 136 15%. 15 15% . (15%) 564. 564) 59 61 sample versatility poornutrient poor nutrient media application studied extremophiles 5 18 25 13 1 (15% 6 2 (15 (1 (

Abstract Objective: The purpose of this study is to develop an agrotourism plan along with its value chain, focusing on Finca Saquifrancia. Methodology: The adopted methodology was characterized as a bibliographic research, combined with a field study, of a descriptive nature and with a nonexperimental cross-sectional design. Result: The structure of agrarian tourism was based on three essential components: the provision of accommodation, agricultural production, and industrial activity. This approach took into account the dynamics of the market, the service offerings, and the proposed activities. The successful integration of tourism into economic, social, cultural, and environmental contexts requires effective planning and management. Limitations: The farm is in a situation where it faces significant restrictions in the promotion of its tourism services, specifically in the agrotourism sector, which represents an emerging and expanding market segment. Conclusion: As a result of this structure, the agroindustrial estate has promoted the development of agrotourism in the region, offering an innovative proposal and achieving significant progress in its organizational structure.

Resumen Objetivo: El propósito de este estudio consiste en la elaboración de un plan agroturístico junto con su cadena de valor, focalizado en la Finca Saquifrancia. Metodología: La metodología adoptada se caracterizó por ser una investigación de enfoque bibliográfico, combinada con un estudio de campo, de carácter descriptivo y con un diseño transversal no experimental. Resultado: La estructura del turismo agrario se basó en tres componentes esenciales: la provisión de alojamiento, la producción agrícola y la actividad industrial. Este enfoque tuvo en cuenta la dinámica del mercado, la oferta de servicios y las actividades propuestas. La integración exitosa del turismo en los ámbitos económico, social, cultural y medioambiental demanda una planificación y gestión efectiva. Limitaciones: La finca se encuentra en una situación en la que se enfrenta a restricciones significativas en la promoción de sus servicios turísticos, específicamente en el sector del agroturismo, que representa un segmento de mercado emergente y en expansión. Conclusión: A raíz de esta estructura, la finca agroindustrial ha impulsado el desarrollo del agroturismo en la región, aportando una propuesta innovadora y logrando un progreso significativo en su estructura organizacional.

Resumen El patrimonio cultural inmaterial forma parte de la herencia de nuestros antepasados, que comprende: costumbres, tradiciones, prácticas y técnicas, que a través del tiempo han sido transmitidas de generación en generación, conformado por la autenticidad y creatividad de un pueblo. Actualmente el patrimonio cultural en la ciudad de Riobamba es de gran valor histórico y artístico, por lo que cabe mencionar que existen fiestas más destacadas que otras, pero al alcance no es suficiente para fortalecer y promocionar el patrimonio cultural existente. El objetivo de la presente investigación es analizar la incidencia del patrimonio cultural inmaterial en el desarrollo turístico en la ciudad de Riobamba, visualizado como una estrategia de conservación y difusión. La investigación es mixta, descriptivo y correlacional, las mismas que dieron como resultado que en promedio el 52,94% de los técnicos del Gobierno Autónomo Descentralizado del cantón Riobamba, coinciden estar de acuerdo en que se debe fortalecer la promoción turística del patrimonio cultural inmaterial a través de la comunicación digital. Por otro lado, con el 47,26% de la población riobambeña, muestran interés en que se implemente una guía digital cultural para promocionar el desarrollo turístico de la localidad. De acuerdo al cálculo del chi cuadrado de la hipótesis general se obtuvo como resultado el valor de 0.000 lo que confirma que existe una influencia significativa del patrimonio cultural inmaterial en el desarrollo turístico en la ciudad de Riobamba, provincia de Chimborazo.

Abstract The intangible cultural heritage is part of the heritage of our ancestors, which includes: customs, traditions, practices and techniques, which over time have been transmitted from generation to generation, shaped by the authenticity and creativity of a people. Currently the cultural heritage in the city of Riobamba is of great historical and artistic value, so it is worth mentioning that there are more outstanding festivals than others, but the scope is not enough to strengthen and promote the existing cultural heritage. The objective of this research is to analyze the impact of intangible cultural heritage on tourism development in the city of Riobamba, visualized as a conservation and dissemination strategy. The research is mixed, descriptive and correlational, which resulted in an average of 52.94% of the technicians of the Decentralized Autonomous Government of the canton of Riobamba, agree that tourism promotion of intangible cultural heritage should be strengthened through digital communication. On the other hand, with 47.26% of the population of Riobamba, they show interest in the implementation of a cultural digital guide to promote tourism development in the town. According to the calculation of the chi-square of the general hypothesis, a value of 0.000 was obtained, which confirms that there is a significant influence of the intangible cultural heritage on tourism development in the city of Riobamba, province of Chimborazo.

Resumen Al no existir metodologías estandarizadas para el diseño del fluido de perforación en función de caracterización de la roca, revisión de fluidos de pozos de referencia, interacción roca-fluido, nuestro objetivo es obtener la mejor formulación en cada sección, que es específica para cada campo, la que debe ser compatible con las formaciones en las que se están perforando. Metodológicamente se describen los pasos para obtener la mejor formulación compatible con las formaciones en las que se están perforando; caracteriza las rocas de las formaciones geológicas como son: terciario indiferenciado, Orteguaza, Tiyuyacu, Tena y Napo, distribuidas en tres secciones 16”, 12 ¼” y 8 ½”, mediante parámetros: tiempo de succión capilar, capacidad de intercambio catiónico, erosión/dispersión, acreción e hinchamiento lineal, los mismos proporcionan información de reactividad de la formación, posterior selección de formulaciones en pozos de referencia y evaluación en pruebas de interacción roca fluido. Los resultados establecieron un parámetro para evaluar y categorizar el desempeño de la prueba según la contribución al desempeño del fluido, la tecnología, la precisión y la repetibilidad de la prueba, siendo 1 la menor prioridad y 3 la mayor prioridad.

Abstract As there are no standardized methodologies for drilling fluid design based on rock characterization, reference well fluid review, rock-fluid interaction, our goal is to obtain the best formulation in each section, which is specific to each field, which must be compatible with the formations being drilled. Methodologically, the steps to obtain the best formulation compatible with the formations in which they are drilling are described; characterizes the rocks of geological formations such as: undifferentiated tertiary, Orteguaza, Tiyuyacu, Tena and Napo, distributed in three sections 16”, 12 ¼” and 8 ½”, through parameters: capillary suction time, cation exchange capacity, erosion /dispersion, accretion and linear swelling, they provide information on the reactivity of the formation, subsequent selection of formulations in reference wells and evaluation in rock-fluid interaction tests. The results established a parameter to evaluate and rank test performance based on contribution to fluid performance, technology, accuracy, and test repeatability, with 1 being the lowest priority and 3 being the highest priority.

Resumen: Analizamos el predicamento del desarrollo sustentable y regenerativo enmarcado en la experiencia globalizante del cambio global, con la gran aceleración de las últimas décadas. Con el fin de plantear opciones prácticas de adaptación al cambio climático y de incrementar la resiliencia, se presenta el caso del Chimborazo como referente global para incorporar la transdisciplinariedad de la montología, presentada como la ciencia convergente de las montañas, consideradas como híbridos de naturaleza y cultura. En la Reserva de Producción Faunística de Chimborazo, los objetivos de conservación y las prácticas de manejo del área protegida se han ceñido a los paradigmas antiguos de naturaleza prístina, en vez de reflejar la realidad de un sistema socioecológico productivo de data ancestral. Presentamos argumentos para reformular el status quo con la noética y la consiliencia de los nuevos paradigmas inclusivos, como la historicidad, la transgresividad y la referencialidad del estudio de montañas. Así reclamamos la necesidad de asignar al paisaje montano del Chimborazo con una nueva categoría; sea geoparque, reserva de la biosfera o sitio mundial de patrimonio mixto (natural y cultural).

Abstract: We analyze the predicament of sustainable and regenerative development, framed in the planetary experience of global change, within the great acceleration of recent decades. In order to propose practical options for adaptation to climate change and increase resilience, the case of Mt. Chimborazo is presented as a badge referent to incorporate the transdisciplinarity of montology, presented as the convergent science of mountains, considered as hybrid of nature and culture. In the Chimborazo Faunal Production Reserve, the conservation objectives and management practices of the mountain protected area have adhered to the old paradigms of pristine nature, instead of reflecting the reality of a productive socio-ecological system of ancestral data. We present the argument in favor of reformulating status quo with noetics and the consilience of the new inclusive paradigms, such as the historicity, the transgressiveness and the referentiality of the study of mountains. Thus, we claim the need of assigning Chimborazo mountainscape a newer category, whether geopark, biosphere reserve, or mixed (natural-cultural) world heritage site.

Abstract Background: Acidophilic microorganisms like Leptospirillum sp. CF 1 thrive in environments with extremely low pH and high concentrations of dissolved heavy metals that can induce the generation of reactive oxygen species (ROS). Several hypothetical genes and proteins from Leptospirillum sp. CF 1 are known to be up regulated under oxidative stress conditions. Results: In the present work, the function of hypothetical gene ABH19_09590 from Leptospirillum sp. CF 1 was studied. Heterologous expression of this gene in Escherichia coli led to an increase in the ability to grow under oxidant conditions with 5 mM K2CrO4 or 5 mM H2O2. Similarly, a significant reduction in ROS production in E. coli transformed with a plasmid carrying ABH19_09590 was observed after exposure to these oxidative stress elicitors for 30 min, compared to a strain complemented with the empty vector. A co transcriptional study using RT PCR showed that ABH19_09590 is contained in an operon, here named the “och” operon, that also contains ABH19_09585, ABH19_09595 and ABH19_09600 genes. The expression of the och operon was significantly up regulated in Leptospirillum sp. CF 1 exposed to 5 mM K2CrO4 for 15 and 30 min. Genes of this operon potentially encode a NADH:ubiquinone oxidoreductase, a CXXC motif containing protein likely involved in thiol/disulfide exchange, a hypothetical protein, and a di hydroxy acid dehydratase. A comparative genomic analysis revealed that the och operon is a characteristic genetic determinant of the Leptospirillum genus that is not present in other acidophiles. Conclusions: Altogether, these results suggest that the och operon plays a protective role against chromate and hydrogen peroxide and is an important mechanism required to face polyextremophilic conditions in acid environments.

Abstract Three reproductive protocols were evaluated: 1) PG: injection of PGF2α on d-50 postpartum and insemination (AI) based on estrus detection. 2) OVS (Ovsynch: d 0, GnRH; d 7, PGF2α; d 9, GnRH; d 10, AI); 3) ROV (GnRH + Ovsynch: d- 7, GnRH; d 0, GnRH; d 7 PGF2α; d 9, GnRB; d 10, AI). In addition, the effect of somatotropin (bST) to AI, on fertility at first postpartum service (FERT), and pregnancy rate at 99 d postpartum (PP) FERT was similar in ROV and OVS (36.2 vs 36.6 %) (P>0.05); and higher than PG (27.3 %) (P<0.05). Likewise, FERT was similar with and without bST (36.2 vs 30.6 %, P>0.05). PG and without bST (22.5 %) was lower than OVS with (38.5 %) and without bST (33.7 %), as well as than ROV with (37.0 %) and without bST (36.1 %), and PG with bST (32.9 %). The pregnancy rate at 99 d was: OVS (60.6 %); ROV (54.3 %), higher than PG group (46.8 %) (P>0.05). OVS with (64.7 %) and without bST (56.5 %) and ROV without bST were higher than PG without bST (41.1 %, P<0.05). In conclusion, GnRH before Ovsynch (ROV) and bST at AI did not increase fertility at the first service in Holstein cows under heat stress. OVS and ROV increased fertility of first service postpartum and pregnancy rate to 99 d postpartum. Somatotropin increased fertility of first postpartum service only in PG treated cows.

Resumen: Tres protocolos reproductivos fueron evaluados: 1) PG: inyección de PGF2α en el día 50 posparto e inseminación (IA) en base a detección del estro. 2) OVS (Ovsynch: día 0, GnRH; día 7, PGF2α; día 9, GnRH; día 10, IA); y 3) ROV (GnRH + Ovsynch: día- 7, GnRH; día 0, GnRH; día 7, PGF2α; día 9, GnRH; día 10, IA). Además, el efecto de la somatotropina (bST) a la IA, sobre la fertilidad al primer servicio posparto (FERT), y la tasa de preñez a 99 días posparto (PP). FERT fue similar en ROV y OVS (36.2 vs 36.6 %) (P>0.05); y mayor a PG (27.3 %) (P<0.05). Igualmente, FERT fue similar con bST y sin bST (36.2 vs 30.6 %, P>0.05). PG y sin bST (22.5 %) fue menor que OVS con (38.5 %), y sin bST (33.7 %); y que ROV con bST (37.0 %) y sin bST (36.1 %); y PG con bST (32.9 %) (P<0.05). La tasa de preñez a 99 días PP fue: OVS (60.6 %); ROV (54.3 %), superior al grupo PG (46.8 %) (P<0.05). OVS con bST (64.7 %), y sin bST (56.5 %), y ROV sin bST fueron mayores que PG sin bST (41.1 %, P<0.05). En conclusión, GnRH previo al Ovsynch (ROV) y la bST al momento de la IA no incrementaron la fertilidad del primer servicio en vacas Holstein en estrés calórico. OVS y ROV incrementaron la fertilidad del primer servicio posparto y la tasa de preñez a 99 días posparto. La somatotropina incrementó la fertilidad del primer servicio posparto solo en vacas tratadas con PG.

Abstract Background: Pectinase enzymes catalyze the breakdown of pectin, a key component of the plant cell wall. At industrial level, pectinases are used in diverse applications, especially in food-processing industry. Currently, most of the industrial pectinases have optimal activity at mesophilic temperatures. On the contrary, very little is known about the pectinolytic activities from organisms from cold climates such as Antarctica. In this work, 27 filamentous fungi isolated from marine sponges collected in King George Island, Antarctica, were screened as new source of cold-active pectinases. Results: In semi-quantitative plate assays, 8 out 27 of these isolates showed pectinolytic activities at 15 °C and one of them, Geomyces sp. strain F09-T3-2, showed the highest production of pectinases in liquid medium containing pectin as sole carbon source. More interesting, Geomyces sp. F09-T3-2 showed optimal pectinolytic activity at 30 °C, 10 °C under the temperature of currently available commercial mesophilic pectinases. Conclusion: Filamentous fungi associated with Antarctic marine sponges are a promising source of pectinolytic activity. In particular, pectinases from Geomyces sp. F09-T3-2 may be potentially suitable for biotechnological applications needing cold-active pectinases. To the best of our knowledge, this is the first report describing the production of pectinolytic activity from filamentous fungi from any environment in Antarctica.

OBJETIVO: O objetivo deste estudo foi avaliar a eficácia da irrigação ultrassônica passiva (IUP), utilizando os fluxos intermitente ou contínuo, e da irrigação manual convencional (IMC) na limpeza de canais radiculares, principal e laterais simulados.MATERIAL E MÉTODO: Os canais radiculares de 24 dentes artificiais foram preparados e os canais laterais foram confeccionados nos terços médio e apical. Os espécimes foram divididos em três grupos: G1- IMC, G2- IUP 1 (fluxo intermitente) e G3- IUP 2 (fluxo contínuo). Os canais radiculares foram preenchidos com uma solução de contraste e as raízes foram radiografadas antes e após a irrigação. As imagens digitais foram importadas para o programa Image Tool 3.0 e as áreas do canal totalmente preenchidas com o contraste, e após a irrigação, com remanescente do contraste, foram mensuradas para obtenção de dados percentuais. A análise estatística entre os grupos foi realizada por meio dos testes ANOVA e Tuckey.RESULTADO: No terço apical, os grupos G2 e G3 (IUP) mostraram melhor limpeza do que o grupo G1 (IMC) (p<0.05). Não houve diferenças estatisticamente significantes entre os grupos G2 e G3 (p>0.05).CONCLUSÃO: Irrigação ultrassônica passiva com fluxo intermitente promoveu melhor limpeza dos canais laterais simulados do que a irrigação manual convencional no terço apical do canal radicular. Não houve diferenças entre os grupos no canal principal e no terço médio.

OBJECTIVE: To evaluate the efficacy of passive ultrasonic irrigation (PUI) using intermittent or continuous flushing and conventional manual irrigation (CMI) on the cleaning of main and simulated lateral root canals.MATERIAL AND METHOD: The root canals of 24 artificial teeth were prepared and simulated lateral canals were made in the medium and apical thirds of the root. The specimens were divided into three groups: G1- CMI, G2- PUI 1 (intermittent flushing) and G3- PUI 2 (continuous flushing). Root canals were filled with contrast solution and the roots were radiographed pre- and post-irrigation. The digital images were transferred to Image Tool 3.0 software and the areas of root canal completely filled with contrast, and after irrigation with contrast remnant, were measured to obtain percentage data. Statistical analysis between groups was performed by ANOVA and Tukey tests.RESULT: In the apical third, G2 and G3 (PUI) groups showed higher percentage of cleaning than G1 (CMI) (p<0.05).CONCLUSION: Passive ultrasonic irrigation using intermittent flushing promoted a higher cleaning of simulated lateral canals than conventional manual irrigation in the apical third. There were no differences between groups in the main root canal and the middle third.

Evaluation of the second stage of labor is still subjective. Translabial intrapartum ultrasound is an objective evaluation tool of progression of the various stages of childbirth. Objectives: To determine the usefulness of translabial intrapartum ultrasound study in determining duration of the second stage of labor. Design: Observational, prospective and relationship study. Setting: Honorio Delgado Regional Hospital, Arequipa, Peru. Participants: Women in the second stage of labor. Interventions: From April through July 2012 53 patients in second stage of labor and who delivered vaginally underwent translabial ultrasound assessment of variety of position, direction, and angle of progression of the cephalic descent and its relation with duration of the second stage. Main outcome measures: Relation of cephalic descent and duration of the second stage. Results: There was a significant statistical relation (P < 0.05) between progression of the cephalic descent angle and duration of the second stage. According to simple linear regression, a greater progression angle predicted less duration of the second stage of labor. There was also statistically significant relationship (P < 0.05) between duration and direction of the cephalic descent. Finally, the relationship between time and the variety of presentation was statistically significant (P < 0.05). Conclusions: Determination of the range of position, angle of progression and direction of the cephalic descent by using translabial ultrasound was useful to determine the duration of the second stage.

La evaluación del periodo expulsivo del trabajo de parto sigue siendo subjetiva. La ecografía intraparto por vía translabial es una herramienta de evaluación objetiva de la progresión de las diferentes etapas del parto. Objetivos: Determinar la utilidad de la ecografía intraparto por vía translabial en la determinación de la duración del periodo expulsivo del trabajo de parto. Diseño: Estudio de tipo observacional, prospectivo y de relación. Institución: Hospital Regional Honorio Delgado, Lima, Perú. Participantes: Gestantes en periodo expulsivo del trabajo de parto. Intervenciones: Desde abril a julio del 2012, a 53 pacientes en periodo expulsivo y cuyo parto terminó por vía vaginal, se les realizó evaluación ecográfica translabial de la variedad de posición, dirección y ángulo de progresión del descenso cefálico, y se relacionó con la duración del periodo expulsivo. Se efectuó regresión lineal simple para asociar cuantitativamente el tiempo de duración del periodo expulsivo con el ángulo de progresión del descenso cefálico, y la prueba chi2 de independencia para asociar cualitativamente el tiempo, la dirección del descenso cefálico y la variedad de posición. Principales medidas de resultados: Relación de las modificaciones del ángulo de progresión del descenso cefálico y la duración del periodo expulsivo. Resultados: Se encontró relación estadística significativa (p<0,05) entre el ángulo de progresión del descenso cefálico y el tiempo de duración del periodo expulsivo. Según la regresión lineal simple, a mayor ángulo de progresión menor fue la duración del periodo expulsivo. Además, entre el tiempo y la dirección del descenso cefálico, hubo relación estadísticamente significativa (p<0,05). Finalmente, la relación entre el tiempo y la variedad de presentación fue estadísticamente significativa (p<0,05). Conclusiones: La determinación de la variedad de posición, ángulo de progresión y dirección del descenso cefálico mediante ecografía translabial resultarían útiles para determinar la duración del periodo expulsivo.

The gametogenic cycle of the black clam Chione fluctifraga of northwestern Mexico, collected from March 2009 through February 2010, was studied using conventional histological techniques and oocyte modal analysis. A condition index was also determined. Clams exhibited a semi-annual gametogenic cycle. The species generated the first oocyte cohort in spring (April) started its vitellogenic growth and remained continuous over 9 months until early winter (December). A resting period occurs in winter. Clams released gametes continuously throughout the reproductive period, but the main spawning occurred during the warmest period (>28°C). Gametogenic activity seemed to be strongly regulated by water temperature. The average growth rate of oocyte cohorts was calculated (0.41 ± 0.10 µm day_1), with the most rapid growth (0.67 µm day_1) from September through October. The condition index was higher in summer, but other peaks occurred in winter, producing accumulation of nutrients from increased phytoplankton biomass. The female:male ratio was 1:1.3; no hermaphrodites were detected. A reproductive classification is proposed. These results can help regulate exploitation and establish off-limit periods for this clam in the Gulf of California.

El ciclo gametogénico de la almeja negra Chione fluctifraga en el noroeste de México fue estudiado mediante técnicas histológicas convencionales y distribuciones de talla de ovocitos (análisis modal) durante marzo 2009-febrero 2010. Adicionalmente se determinó un índice de condición general. Las almejas presentaron un ciclo gametogénico semianual. La especie inició la formación de la primera cohorte ovocitaria en primavera (abril) comenzando así su crecimiento vitelogénico que se mantuvo continuo durante 9 meses hasta finales de otoño (diciembre), para posteriormente pasar a un periodo de reposo durante invierno. Las almejas liberaron constantemente gametos al medio pero presentaron los principales desoves durante el periodo más cálido (>28°C). La actividad gametogénica pareció estar fuertemente controlada por la temperatura del agua. Se calculó la tasa promedio de crecimiento de las cohortes ovocitarias (0,41 ± 0,10 µm día-1) registrándose un máximo de 0,67 µm día-1 entre septiembre-octubre. El índice de condición (IC) fue mayor en verano, aunque otro pico ocurrió en invierno produciéndose una acumulación de nutrientes a partir de un incremento de biomasa de fitoplancton. La proporción de sexos (hembra: macho) fue 1:1,3 y no se encontraron almejas hermafroditas. Se propone una escala reproductiva para la especie. Estos resultados pueden contribuir en las regulaciones de explotación y establecimiento de vedas biológicas del recurso en el Golfo de California.

Dens invaginatus, also known as "dens in dente", is a developmental dental anomaly resulting in an invagination of the enamel organ into the dental papilla. These cases present technical difficulties to the root canal treatment. Apexification using an apical plug of mineral trioxide aggregate (MTA) has been indicated as an alternative to long-term intracanal use of calcium hydroxide in immature permanent teeth. It is considered as a simple and rapid technique. This paper reports a case of Oehlers' Type 1 dens invaginatus in an immature permanent maxillary right lateral incisor, which presented pulp necrosis secondary to dental trauma and was treated by apexification with white MTA apical plugging followed by conventional root canal therapy. The operative procedures are described and the technique is discussed. The physical and biological properties of MTA, associated with appropriate instrumentation and obturation techniques, make this material an excellent option in the endodontic therapy of immature permanent teeth with dens invaginatus.

Introduction: No studies were encountered determining changes of the pulmonary artery trunk flow velocity waveform with the use of corticosteroids. Objectives: To determine the effect of antenatal corticosteroids on the pulmonary artery trunk acceleration time/systolic ejection time index (AT/ET index) in preterm fetal pregnancies and to correlate a possible variation in the AT/ET ratio with the induction of lung maturity. Design: Descriptive, prospective, longitudinal study. Setting: Hospital Regional Honorio Delgado, Arequipa, Peru. Participants: Preterm fetuses. Interventions: Fetuses had ultrasound evaluation with biometry and measurement of the pulmonary artery trunk blood flow by using pulsed Doppler, before and after administration of corticosteroids for fetal lung maturity. Results used descriptive statistics and were compared by paired tests and correlation tests. Main outcome measures: Variation of the fetal pulmonary artery trunk AT/ET index by use of corticosteroids. Results: We studied 35 pregnant women with mean age 27.2 years, mean gestational age 33.1 weeks. Mortality of preterm infants was 11.4% of all births. AT/ET index following corticosteroids administration rose from 0.26 to 0.29 (p <0.05). AT/ET index increase in relation to baseline below 20% was associated with need for neonatal intubation, cardiac massage, drugs use, congenital pneumonia, need of ICU admission, mechanical ventilation, and mortality. Conclusions: Preterm pulmonary artery trunk flow AT/ET ratio increased significantly with the administration of antenatal steroids, and its elevation above 20% from baseline diminished the presence of important complications in the preterm newborn.

Introducción: No se cuenta con estudios de las modificaciones de la onda de velocidad de flujo del tronco de la arteria pulmonar por el uso de corticoides. Objetivos: Evaluar el efecto del uso de corticoides prenatales sobre la medida del índice Doppler tiempo de aceleración/tiempo de eyección sistólico (TA/TE) en el flujo del tronco de la arteria pulmonar fetal en el embarazo pretérmino, y correlacionar una posible variación en el índice TA/TE con la inducción de madurez pulmonar fetal. Diseño: Estudio descriptivo, prospectivo y longitudinal. Institución: Hospital Regional Honorio Delgado, Arequipa, Perú. Participantes: Fetos pretérmino. Intervenciones: Evaluación ultrasonográfica obstétrica con biometría fetal y medición del flujo sanguíneo en el tronco de la arteria pulmonar fetal, usando el Doppler pulsado, antes y después de la administración de corticoides para maduración pulmonar fetal. Se muestra los resultados mediante estadística descriptiva y se los compara mediante pruebas pareadas y con pruebas de correlación. Principales medidas de resultados: Variación del índice TA/TE del tronco de la arteria pulmonar por el uso de corticoides. Resultados: Se evaluó 35 gestantes con edad promedio 27,2 años, edad gestacional promedio 33,1 semanas. El índice TA/TE luego de la administración de corticoides se elevó de 0,26 a 0,29 (p < 0,05). El incremento del índice TA/TE en relación a la basal inferior al 20% se encontró en la necesidad de intubación del neonato, de realización de masaje cardiaco, administración de medicamentos, presentación de neumonía congénita, necesidad de admisión en UCI y ventilación mecánica, así como con mortalidad de los neonatos. Conclusiones: La medición del índice TA/TE en el flujo del tronco de la arteria pulmonar fetal en el embarazo pretérmino aumenta significativamente con la administración de corticoides prenatales, y su elevación por encima de 20% en relación a la medición basal disminuye la presencia de complicaciones importantes en el recién nacido pretérmino.

Animal products traceability has acquired considerable importance as a security measure in EEC member countries since the food crisis of the mid-nineties. This has led to reinforcing the capacity to manage cattle product quality, with traceability emerging as the main tool to prevent risks to product security and quality as demanded by consumers in developed countries. The practical application of a traceability system for beef, based on molecular markers requires the election of a panel of microsatellites, as well as the optimization of methods of sampling and DNA analysis. In this work, a traceability system for beef based on a panel of 10 microsatellites markers was implemented. Different biological samples were evaluated, such as hair, blood, tissue and meat. Hair samples were the most suitable because they are easy to obtain and to manipulate, and have a low storage cost; whereas in the food processing chain, meat samples were the most suitable due to the facility of obtaining from the maturation room. The traceability system was evaluated in a meat processing plant, confirming traceability of 150 samples of hair with their respective meat counterparts with a 100% of certainty, demonstrating the reliability of the developed method. The implemented system is an important contribution since it allows for ensuring the quality of animal products, and can be used as a tool to certify conventional traceability systems. This would allow for increasing the competitiveness of this sector and generating greater confidence among consumers.

La trazabilidad de productos de origen animal ha adquirido gran relevancia como un elemento de seguridad ante las crisis alimentarias ocurridas a partir de mediados de los noventa en países de la Comunidad Europea. Esto ha reforzado la gestión de calidad en productos pecuarios, surgiendo la trazabilidad como la principal herramienta para disminuir los riesgos de seguridad y calidad de los productos que demandan los consumidores de países desarrollados. La aplicación práctica de un sistema de trazabilidad de la carne bovina basado en marcadores moleculares, requiere la elección de microsatélites y optimizar los métodos de muestreo y análisis de ADN. En este trabajo se implementó un sistema de trazabilidad de carne bovina basado en un panel de 10 marcadores microsatélites. Se evaluaron diferentes muestras biológicas como pelo, sangre, tejido y carne de la canal, encontrándose que las muestras de pelo fueron las más idóneas por su facilidad de obtención, manipulación y costo de almacenamiento, mientras que la carne de la canal fue la contramuestra más adecuada, pudiendo obtenerse fácilmente en el frigorífico. El sistema se evaluó en una planta de procesamiento de carne, confirmando con un 100% de certeza la trazabilidad de 150 muestras de pelo con sus respectivas canales, demostrando la confiabilidad del método desarrollado. El sistema evaluado puede ser un importante aporte al sector pecuario del país pues permite garantizar el origen de los productos bovinos y puede ser utilizado como herramienta certificadora de la trazabilidad convencional, aumentando la competitividad y generando mayor confianza en el consumidor.

The expression of the acetyl xylan esterase II (axeII) gene from Penicillium purpurogenum is repressed by glucose and induced by xylan, as well as to a small degree by xylose and xylitol. This gene is expressed at neutral pH, but not under alkaline or acidic conditions, in agreement with previous findings for other xylanolytic genes of this organism. This is the first report showing pH regulation of an axe gene.