235 research outputs found

    Spindle-E acts antivirally against alphaviruses in mosquito cells

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    Mosquitoes transmit several human- and animal-pathogenic alphaviruses (Togaviridae family). In alphavirus-infected mosquito cells two different types of virus-specific small RNAs are produced as part of the RNA interference response: short-interfering (si)RNAs and PIWI-interacting (pi)RNAs. The siRNA pathway is generally thought to be the main antiviral pathway. Although an antiviral activity has been suggested for the piRNA pathway its role in host defences is not clear. Knock down of key proteins of the piRNA pathway (Ago3 and Piwi5) in Aedes aegypti-derived cells reduced the production of alphavirus chikungunya virus (CHIKV)-specific piRNAs but had no effect on virus replication. In contrast, knock down of the siRNA pathway key protein Ago2 resulted in an increase in virus replication. Similar results were obtained when expression of Piwi4 was silenced. Knock down of the helicase Spindle-E (SpnE), an essential co-factor of the piRNA pathway in Drosophila melanogaster, resulted in increased virus replication indicating that SpnE acts as an antiviral against alphaviruses such as CHIKV and the related Semliki Forest virus (SFV). Surprisingly, this effect was found to be independent of the siRNA and piRNA pathways in Ae. aegypti cells and specific for alphaviruses. This suggests a small RNA-independent antiviral function for this protein in mosquitoes

    Estilos de vida en relación a la alimentación y hábitos alimentarios dentro y

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    Lobos, G (Lobos, German). Univ Talca, Fac Ciencias Empresariales, Escuela Ingn Comercial, Talca, ChileResumen Objetivo: Distinguir tipologías de consumidores en base a su estilo de vida en relación a la alimentación en las principales comunas de la Región Metropolitana de Santiago, Chile, y caracterizarlas según sus hábitos de consumo de alimentos dentro y fuera del hogar, características sociodemográficas y su nivel de satisfacción con su alimentación. Material y método: Se aplicó un cuestionario estructurado a una muestra de 951 personas en las principales comunas de la Región Metropolitana de Santiago (más de 100.000 habitantes). El instrumento de recogida de información incluyó una adaptación del cuestionario de estilos de vida en relación a la alimentación (FRL) y la escala SWFL (Satisfaction with Food-related Life). Se consultaron los hábitos de consumo de alimentos dentro y fuera del hogar y variables de clasificación sociodemográfica de los encuestados. Resultados: Mediante análisis cluster se distinguieron cinco tipologías con diferencias significativas en los cinco componentes obtenidos del FRL, con análisis factorial de componentes principales. Las tipologías presentaron distinto perfil de género, edad y nivel socioeconómico y difirieron en los puntajes obtenidos en la SWFL. Se diferenciaron en la frecuencia en que la persona almuerza, toma once y cena en su hogar. Respecto a las comidas fuera del hogar, las tipologías se distinguieron según la frecuencia de comidas en restaurantes, locales de comida rápida y en la compra de comida preparada. Conclusiones: Un estilo de vida en relación a la alimentación con baja implicación y disfrute de los alimentos se asocia con un mayor nivel socioeconómico y menor edad de las personas. Adicionalmente, se asocia con comportamientos alimentarios poco saludables y no beneficiosos para las personas, como una mayor frecuencia de comidas en restaurantes y de compra de comida preparada, junto a una menor frecuencia de comidas en el hogar, lo que estaría influyendo en un nivel inferior de satisfacción con la alimentación

    Разработка информационных систем управления рисками для предметных областей

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    This paper is about specifics of developing risk management information system in construction company and advertising business

    Preferencias hacia carne de cordero en supermercados de Temuco, región de la Araucanía, Chile

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    Lobos, G (Lobos, German). Univ Talca, Escuela Ingn Comercial, Talca, ChileThe low levels of consumption of lamb meat in Chile suggest the need for studies on consumer preferences in order to orient production. A study with this object was carried out to evaluate preferences for various cuts, breeds, state (fresh or frozen) and price of lamb's meat among supermarket buyers in Temuco, Chile, and the existence of different market segments, through a survey of 400 persons. Using a fractional factorial design for conjoint analysis, it was determined that the state of the meat was more important than the cut, the price and the breed, with a preference for meat in half carcasses and quarters, Araucano lamb, fresh, at a medium price level. Four consumer segments were distinguished by analysis of hierarchic conglomerates. The majority group (47.7%) was sensitive to the state and the cut, with preference for meat in quarters, fresh, Texel breed. The second group (25.3%) was sensitive to the breed, presenting the strongest preferences for meat in whole carcass, fresh, Araucano lamb. The third group (14.3%) was sensitive to the price, preferred meat in quarters, fresh, Araucano lamb. The minority group (12.7%) was sensitive to the state and price, preferring meat in quarters, Texel breed, and was the only group which preferred frozen meat and would pay a higher price. The segments were distinguished by age, ethnic origin and satisfaction with food-related life. Thus the commercialisation strategy for lamb in supermarkets in Temuco should concentrate principally on the sale of fresh meat cut in quarter

    The Relation between Attitudes toward Functional Foods and Satisfaction with Food-Related Life

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    Purpose – To assess the effect of attitudes towards functional foods (FF) on university students’ satisfaction with food-related life and to distinguish student typologies, considering that the attitudes towards FF are not homogeneous among consumers. Design/methodology - A survey was applied to 372 university students (mean age=20.4 years, SD=2.4) in southern Chile. The questionnaire included the Attitudes towards Functional Foods (AFF) questionnaire and the Satisfaction with Food-related Life (SWFL) scale, questions about consumption and knowledge about FF and socio-demographic characteristics. Findings – Using Confirmatory Factor Analysis (CFA) and Structural Equation Modelling, it was found that attitudes toward functional foods directly and significantly influence students’ satisfaction with food-related life. A cluster analysis applied to the Z-scores from the factors obtained by the CFA classified three typologies: Positive towards FF (36.3%), moderately positive towards FF (43.0%) and negative towards FF (20.7%). The positive towards FF type had a significantly greater SWFL score than the negative towards FF type. The types differ according to consumption and knowledge about FF. Research limitations/implications – This study was conducted in the context of only one country in South America. Originality/value – This study is the first that assesses the effect of AFF on satisfaction with food-related life in a sample of university students. Fostering positive attitudes towards FF will allow for a growth in the degree of satisfaction with food-related life of university students with features similar to those of the study sample

    Antiviral RNA interference activity in cells of the predatory mosquito, Toxorhynchites amboinensis

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    Arthropod vectors control the replication of arboviruses through their innate antiviral immune responses. In particular, the RNA interference (RNAi) pathways are of notable significance for the control of viral infections. Although much has been done to understand the role of RNAi in vector populations, little is known about its importance in non-vector mosquito species. In this study, we investigated the presence of an RNAi response in Toxorhynchites amboinensis, which is a non-blood feeding species proposed as a biological control agent against pest mosquitoes. Using a derived cell line (TRA-171), we demonstrate that these mosquitoes possess a functional RNAi response that is active against a mosquito-borne alphavirus, Semliki Forest virus. As observed in vector mosquito species, small RNAs are produced that target viral sequences. The size and characteristics of these small RNAs indicate that both the siRNA and piRNA pathways are induced in response to infection. Taken together, this data suggests that Tx. amboinensis are able to control viral infections in a similar way to natural arbovirus vector mosquito species. Understanding their ability to manage arboviral infections will be advantageous when assessing these and similar species as biological control agents

    Delaying academic tasks and feeling bad about it

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    Abstract. Procrastination is the irrational delay of an intended task and is common among students. A delay can only be defined as procrastination when it is voluntary, the action was intended but not implemented, and the delay is accompanied by subjective discomfort. Established scales of procrastination cover mainly behavioral aspects but have neglected the emotional aspect. This inaccuracy concerning the construct validity might entail misconceptions of procrastination. Accordingly, we developed and validated the Behavioral and Emotional Academic Procrastination Scale (BEPS), which covers all aspects of the definition of procrastination. The 6-item scale measuring self-reported academic procrastination was tested in three studies. Study 1 (N = 239) evaluated the psychometric qualities of the BEPS, indicating good item characteristics and internal consistency. Study 2 (N = 1,441) used confirmatory factor analysis and revealed two correlated factors: one covering the behavioral aspect and the other reflecting the emotional aspect. Measurement invariance was shown through longitudinal and multigroup confirmatory factor analyses. Study 3 (N = 234) provided evidence for the scale’s convergent validity through correlations with established procrastination scales, self-efficacy, and neuroticism. The BEPS thus economically operationalizes all characteristics of academic procrastination and appears to be a reliable and valid self-report measure

    Antiviral RNAi response in Culex quinquefasciatus-derived HSU cells

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    Culex spp. mosquitoes are important vectors of viruses, such as West Nile virus, Eastern equine encephalitis virus and Rift valley fever virus. However, their interactions with innate antiviral immunity, especially RNA interference (RNAi), are not well known. Most research on RNAi pathways in mosquitoes is focused on the tropical vector mosquito Aedes aegypti. Here, we investigated the production of arbovirus-specific small RNAs in Cx. quinquefasciatus-derived HSU cells. Furthermore, by silencing RNAi-related proteins, we investigated the antiviral role of these proteins for two different arboviruses: Semliki Forest virus (SFV) and Bunyamwera orthobunyavirus (BUNV). Our results showed an expansion of Ago2 and Piwi6 in Cx. quinquefasciatus compared to Ae. aegypti. While silencing Ago2a and Ago2b increased BUNV replication, only Ago2b showed antiviral activity against SFV. Our results suggest differences in the function of Cx. quinquefasciatus and Ae. aegypti RNAi proteins and highlight the virus-specific function of these proteins in Cx. quinquefasciatus

    Schmallenberg virus pathogenesis, tropism and interaction with the innate immune system of the host

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    Schmallenberg virus (SBV) is an emerging orthobunyavirus of ruminants associated with outbreaks of congenital malformations in aborted and stillborn animals. Since its discovery in November 2011, SBV has spread very rapidly to many European countries. Here, we developed molecular and serological tools, and an experimental in vivo model as a platform to study SBV pathogenesis, tropism and virus-host cell interactions. Using a synthetic biology approach, we developed a reverse genetics system for the rapid rescue and genetic manipulation of SBV. We showed that SBV has a wide tropism in cell culture and “synthetic” SBV replicates in vitro as efficiently as wild type virus. We developed an experimental mouse model to study SBV infection and showed that this virus replicates abundantly in neurons where it causes cerebral malacia and vacuolation of the cerebral cortex. These virus-induced acute lesions are useful in understanding the progression from vacuolation to porencephaly and extensive tissue destruction, often observed in aborted lambs and calves in naturally occurring Schmallenberg cases. Indeed, we detected high levels of SBV antigens in the neurons of the gray matter of brain and spinal cord of naturally affected lambs and calves, suggesting that muscular hypoplasia observed in SBV-infected lambs is mostly secondary to central nervous system damage. Finally, we investigated the molecular determinants of SBV virulence. Interestingly, we found a biological SBV clone that after passage in cell culture displays increased virulence in mice. We also found that a SBV deletion mutant of the non-structural NSs protein (SBVΔNSs) is less virulent in mice than wild type SBV. Attenuation of SBV virulence depends on the inability of SBVΔNSs to block IFN synthesis in virus infected cells. In conclusion, this work provides a useful experimental framework to study the biology and pathogenesis of SBV
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