127 research outputs found

    CHR11, a chromatin-remodeling factor essential for nuclear proliferation during female gametogenesis in Arabidopsis thaliana

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    Chromatin-remodeling factors regulate the establishment of transcriptional programs during plant development. Although 42 genes encoding members of the SWI2/SNF2 family have been identified in Arabidopsis thaliana, < 10 have been assigned a precise function on the basis of a mutant phenotype, and none have been shown to play a specific role during the gametophytic phase of the plant life cycle. A. thaliana chromatin-remodeling protein 11 (CHR11) encodes an imitation of switch (ISWI)-like chromatin-remodeling protein abundantly expressed during female gametogenesis and embryogenesis in Arabidopsis. To determine the function of CHR11 in wild-type plants, we introduced a hairpin construct leading to the production of double-stranded RNA, which specifically degraded the endogenous CHR11 mRNA by RNA interference (RNAi). Transcription of the RNAi-inducing hairpin RNA was driven by either a constitutive cauliflower mosaic virus 35S promoter (CaMV35S) acting at most stages of the sporophytic phase or a newly identified specific promoter acting at the onset of the female gametophytic phase (pFM1). All adult trans-formants that constitutively lacked sporophytic CHR11 activity showed reduced plant height and small cotyledonary embryos with limited cell expansion. In contrast, RNAi lines in which CHR11 was specifically silenced at the onset of female gametogenesis (megagametogenesis) had normal height and embryo size but had defective female gametophytes arrested before the completion of the mitotic haploid nuclear divisions. These results show that CHR11 is essential for haploid nuclear proliferation during megagametogenesis and cell expansion during the sporophytic phase, demonstrating the functional versatility of SW12/SNF2 chromatin-remodeling factors during both generations of the plant life cycle

    Spermatozoa Obtained From Alpaca vas deferens. Effects of Seminal Plasma Added at Post-thawing

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    The viscous seminal plasma (SP) is currently a major impediment to the handling of ejaculate and the development of some biotechnologies in South American camelids. The vas deferens-collected spermatozoa of alpacas is a useful technique to avoid this problem. On the other hand, SP contains a large protein component that has been implicated in the function of spermatozoa within the female reproductive tract. In this sense, the low fertility achieved using transcervical insemination with frozen-thawed spermatozoa in alpacas could be improved by adding SP. This study aimed to evaluate the effect of the whole SP on some in vitro parameters of alpaca spermatozoa after the freezing-thawing-process and the fertility after artificial insemination. It would contribute to a better understanding of the interaction between thawed sperm cells and SP. Spermatozoa were obtained by surgically diverted vas deferens. The samples were diluted with a Tris-based extender, packaged in straws, and frozen. At thawing, each straw was divided into two post-thawing conditions: with the addition of 10% of PBS (control) or with 10% SP (treatment). The sperm cells were evaluated using dynamic parameters, sperm cell morphology, and morphometry. Fertility was assessed by an artificial insemination trial. All in vitro parameters were analyzed by ANOVA. A heterogeneity test was scheduled for the fertility trial. After the freezing-thawing process, motility and plasma membrane functionality was improved when SP was added. No differences were found for post-thaw viability between the control and treatment samples. The percentage of normal cells was higher with SP at post-thawing, and a decrease of the presence of bent tailed spermatozoa with a droplet in the SP group was observed. The length of the head spermatozoa was 3.4% higher in the samples with PBS compared to those in which SP was added. Females pregnant at day 25 post-insemination were 0/12 (with SP inside the straw) and 1/10 (without SP inside the straw). In conclusion, the presence of 10% SP at post-thawing improves sperm cells' motility, functionality, and morphology, indicating that it would be beneficial to improve the frozen-thawed alpaca's physiology spermatozoa. More fertility trials must be developed to increase this knowledge

    Niveles de glucosa y triglicéridos en plasma seminal y motilidad espermática en COBAYOS alimentadas con 10% más en energÍa digestible

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    The objective the study was to determine the levels of glucose and triglycerides in seminal plasma of 10 guinea pigs, which were fed for a period of 2 months with a diet containing 10% more ED. The level of glucose found in seminal plasma was 11.59 ± 0.5 mg/dL and triglyceride value was 55.95 ± 3.2 mg/dL, while the motility was 97% on average. We conclude that in guinea pigs the levels both glucose and triglycerides were increased by major level of ED in feed, but the spermatic motility was not.El objetivo del presente estudio fue determinar los niveles de los componentes energéticos (glucosa y triglicéridos) en el plasma seminal y la motilidad espermática de 10 cobayos, los cuales fueron alimentados por un período de 2 meses con una dieta 10% mayor en energía digestible (ED). El nivel de glucosa encontrado en plasma seminal fue de 11.59 ± 0.5 mg/dL y el valor de triglicéridos fue de 55.95 ± 3.2 mg/dL, mientras que la motilidad promedio fue de 95%. Concluimos que en cobayos los niveles de glucosa y triglicéridos se incrementan al aumentar el nivel de ED en dieta sin producir alteraciones en la motilidad espermática

    Efecto de la suplementación de proteína y energía sobre la producción láctea, densidad, sólidos totales, grasa y nitrógeno ureico en la leche de vacas Brown Swiss en condiciones hipobáricas naturales

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    This study aimed to determine the effect of the energy / protein ratio of supplementary feed rations (RAS) on the production and characteristics of milk under natural hypobaric conditions (4300 m altitude in Puno, Peru). A total of 24 Brown Swiss cows in first and second third of lactation were distributed in three RAS with three ratios of metabolizable energy / protein (RAS1: 17.0 kcal/g; RAS2: 14.2 kcal/g; RAS3: 12.4 kcal/g) and as a protein source three levels of hydrolysed sheep and alpaca skins – Pioval-2® (0, 3 and 6%, respectively) and three levels of extruded whole soymeal (0, 10 and 25%, respectively). The cows were grazing on alfalfa associated with rye grass and supplemented with oat silage. Daily milk yield (DMY) was recorded for 45 days, as well as density (DE), total solids (TS), fat (FA) and milk urea nitrogen (MUN) at 0, 15, 30 and 45 days. The RAS did not affect the DMY (17.7, 18.8 and 19.0 kg/day) or the DE (1,031, 1,031 and 1,030 g/l, respectively) of the milk. RAS2 increased the TS and FA (13.0%, 4.2%) in relation to RAS1 (12.4%, 3.8%) and RAS3: 12.2%, 3.9%) (p &lt;0.01) in milk, respectively. The decrease of the energy / protein fraction in the rations increased proportionally the MUN (RAS1: 28.9; RAS2: 32.3; RAS3: 36.8 mg/dl; p&lt;0.001). In conclusion, the increase in the energy / protein fraction of the concentrate ration did not affect milk yield or milk density but improved the total solids and fat content; while the reduction of the energy / protein ratio in the ration consistently increased the urea nitrogen in the milk.El estudio tuvo como objetivo determinar el efecto de la ratio energía / proteína de las raciones alimenticias suplementarias (RAS) sobre la producción y características de la leche en condiciones hipobáricas naturales (4300 m de altitud en Puno, Perú). Se distribuyeron al azar 24 vacas Brown Swiss de primer y segundo tercio de lactación en tres RAS con tres ratios de energía metabolizable / proteína (RAS1: 17.0 kcal/g; RAS2: 14.2 kcal/g; RAS3: 12.4 kcal/g) y como fuente de proteína tres niveles de harina hidrolizada de pieles de ovino y alpaca – Pioval-2® (0, 3 y 6%, respectivamente) y tres niveles de harina de soya integral extruida (0, 10 y 25%, respectivamente). Las vacas estaban al pastoreo sobre cultivo de alfalfa asociado a rye grass y recibieron ensilado de avena. Se determinó la producción diaria de leche (PDL) durante 45 días, así como la densidad (DE), sólidos totales (ST), grasa (GR) y nitrógeno ureico en la leche (NUL) a los 0, 15, 30 y 45 días. Las RAS no afectaron la PDL (17.7, 18.8 y 19.0 kg/día) ni la DE (1,031, 1,031 y 1,030 g/l, respectivamente) de la leche. La RAS2 incrementó los ST y GR (13.0%, 4.2%) con relación a RAS1 (12.4%, 3.8%) y RAS3: 12.2%, 3.9%) (p&lt;0.01) en la leche, respectivamente. Con la disminución de la fracción energía / proteína en las raciones el NUL aumentó proporcionalmente (RAS1: 28.9; RAS2: 32.3; RAS3: 36.8 mg/dl; p&lt;0.001). En conclusión, el aumento de la fracción energía / proteína de la ración de concentrado no afectó la producción ni la densidad de la leche, pero mejoró el contenido de sólidos totales y grasa; mientras que la reducción de la ratio energía / proteína en la ración incrementó consistentemente el nitrógeno ureico en la leche

    MEDIDAS DE BIOSEGURIDAD DURANTE LA CONFECCION DE MODELOS DENTALES Y PERCEPCIÓN DE RIESGO EN ESTUDIANTES DE ODONTOLOGÍA

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    Objetivo: Relacionar las medidas de bioseguridad durante la confección de modelos dentales y la percepción de riesgo en estudiantes de odontología de la “Universidad Andina Néstor Cáceres Velásquez”. Materiales y métodos: Investigación analítica, transversal, prospectivo y observacional se aplicó a 60 estudiantes clínicos, seleccionados según criterios de selección muestreo no probabilístico, se aplicó las técnicas de observación y entrevista, mediante una ficha de observación y cuestionario con la escala de Likert, ambas validadas por juicio de expertos. Se contrasto la hipótesis con la prueba de chi cuadrado fue obtenida mediante el uso del programa estadístico SPSS versión 23, con significancia 0.05. Resultados: de 60 clínicos: el 46.60% percibió riesgo alto y ninguno aplico de forma aplicaron en forma regular, y el 23.30% clínicos aplicaron de forma adecuada las conductas esenciales de bioseguridad. Conclusión: la percepción de riesgo se relaciona altamente significativa con las conductas esenciales de bioseguridad durante la confección de los modelos dentales (p=0.0

    Returning to the Past to Rethink Socio-Political Antagonisms: Mapping Today’s Situation in Regards to Popular Insurrections

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    This article seeks to elaborate a map or cartogram based on a number of protests and social mobilizations that took place in different parts of the world -mainly in Latin America, but also in Europe and Asia. Beyond the data and figures available from various sources, which never speak for themselves, an interpretation is proposed here to reveal the meaning of these events. In other words, by displaying a map of these social movements, the authors propose not only the visualization of a collection of data, but also an illumination of these events in the light of history. From there, the authors offer hypothetical predictions. These predictions allow the authors to consider the lessons that, sometimes, seem to be forgotten or are not learned yet

    Some color in the desert: description of a new species of Liolaemus (Iguania: Liolaemidae) from southern Peru, and its conservation status.

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    The desert of southern Peru and northern Chile is an area with a high degree of endemismin squamate reptiles. In this work, an endemic new species is described in the genus Liolaemus with a restricted geographical distribution on the western slopes of the La Caldera batholith in the Department of Arequipa, southern Peru, that inhabits the Desert province of southern Peru, between 1,800 and 2,756 m asl. The new species is characterized by a unique combination of morphological and molecular characters that distinguish it from all other Liolaemus species, and it is included in the L. reichei clade within the L. montanus group. Evidence presented shows that the category of threat corresponds to Endangered under the IUCN Red List criteriaFil: Huamani Valderrama, Ling. Universidad Nacional de San Agustín. Facultad de Ciencias Biológicas. Departamento Académico de Biología. Museo de Historia Natural; PerúFil: Quiroz, Aarón J.. Universidad Nacional de San Agustín. Facultad de Ciencias Biológicas. Departamento Académico de Biología. Museo de Historia Natural; PerúFil: Gutierrez, Roberto C.. Universidad Nacional de San Agustín. Facultad de Ciencias Biológicas. Departamento Académico de Biología. Museo de Historia Natural; PerúFil: Aguilar Kiriguin, Alvaro. Universidad Nacional de San Agustín. Facultad de Ciencias Biológicas. Departamento Académico de Biología. Museo de Historia Natural; PerúFil: Huanca Mamani, Wilson. Universidad de Tarapacá; ChileFil: Valladares Faúndez, Pablo. Universidad de Tarapaca.; ChileFil: Cerdeña, José. Universidad Nacional de San Agustín. Facultad de Ciencias Biológicas. Departamento Académico de Biología. Museo de Historia Natural; PerúFil: Chaparro, Juan C,. Museo de Biodiversidad del Perú; PerúFil: Abdala, Cristian Simón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin

    Profiling of polar ionogenic metabolites in Polish wines by capillary electrophoresis-mass spectrometry

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    The composition of wine is determined by a complex interaction between environmental factors, genetic factors (i.e., grape varieties), and winemaking practices (including technology and storage). Metabolomics using NMR spectroscopy, GC-MS, and/or LC-MS has shown to be a useful approach for assessing the origin, authenticity, and quality of various wines. Nonetheless, the use of additional analytical techniques with complementary separation mechanisms may aid in the deeper understanding of wine's metabolic processes. In this study, we demonstrate that CE-MS is a very suitable approach for the efficient profiling of polar ionogenic metabolites in wines. Without using any sample preparation or derivatization, wine was analyzed using a 10-min CE-MS workflow with interday RSD values for 31 polar and charged metabolites below 3.8% and 23% for migration times and peak areas, respectively. The utility of this workflow for the global profiling of polar ionogenic metabolites in wine was evaluated by analyzing different cool-climate Polish wine samples.Analytical BioScience

    Analisi del reddito di aziende sud americane con allevamento di alpaca e lama

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    L'Altiplano del Perù e della Bolivia, collocato tra 3.800 e 5.000 metri sul livello del mare, si estende per oltre 180.000 chilometri quadrati ed è una eco-regione unica dove sono presenti i più importanti allevamenti di alpaca e lama. Molti studi hanno trattato l'ecosistema e lo sfruttamento agricolo, la genetica del bestiame, i sistemi di coltivazione e di allevamento e lo sviluppo e le condizioni socio-culturali. Pochi, invece, sono gli studi economici delle aziende di allevamento dei camelidi (Westreicher et al., 2006). Obiettivo di questo studio, che fa parte di una ricerca più ampia finalizzata al miglioramento del reddito degli allevatori andini, consiste nell'esame del reddito e del costo di produzione di otto gruppi di aziende del Perù e della Bolivia con allevamento di alpaca e lama per la produzione di fibra e carne: cinque imprese private e tre comunità rurali

    An endemic and endangered new species of the lizard liolaemus montanus group from southwestern peru (Iguania: Liolaemidae), with a key for the species of the l. reichei clade

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    The southwestern Andes of Peru harbor a hidden taxonomic diversity of reptiles. We describe a new species of Liolaemus Wiegmann (Iguania: Liolaemidae) from xerophytic environments of the southwestern slopes of the Andes of Peru, 2,400– 2,900 m asl. The new species, previously considered to be a population of L. insolitus Cei, exhibits unique diagnostic characters of morphology, scalation and color pattern, and molecular evidence that suggest that it belongs in the Liolaemus montanus species group and the L. reichei clade. Moreover, the species is endemic to the eastern slopes of La Caldera batholith in the Department of Arequipa, southern Peru. We also provide information on the conservation status of the species and suggest it be included in the IUCN red list of the threatened species as endangered (EN). A key for the species of the L. reichei clade is provided.Fil: Quiroz, Aarón J.. Universidad Nacional de San Agustin de Arequipa; PerúFil: Huamaní Valderrama, Ling. Universidad Nacional de San Agustin de Arequipa; PerúFil: Gutiérrez, Roberto C.. Universidad Nacional de San Agustin de Arequipa, Museo de Historia Natural; PerúFil: Aguilar Kirigin, Alvaro Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: López Tejeda, Evaristo Luciano. Universidad Nacional de San Agustin de Arequipa; PerúFil: Lazo Rivera, Ana. Universidad Nacional de San Agustin de Arequipa; PerúFil: Huanca Mamani, Wilson. Universidad de Tarapacá; ChileFil: Valladares Faúndez, Pablo. Universidad de Tarapacá; ChileFil: Morrone, Juan José. Universidad Nacional Autónoma de México; MéxicoFil: Cerdeña, José. No especifíca;Fil: Chaparro, Juan C.. No especifíca;Fil: Abdala, Cristian Simón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin
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