15 research outputs found

    Pathogenicity of Entomopathogenic Fungi on the Weevil of the Andes (Premnotrypes vorax Hustache) of the Potato (Solanum tuberosum L.) in Chimborazo Province, Ecuador

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    From thirty native isolates of entomopathogenic fungi, which were obtained from corpses of larvae and adults of Andean weevil (Premnotrypes vorax Hustache); two fungi with entomopathogenic characteristics were selected through laboratory tests, which will be used in a program of integrated management of this pest in the Ecuadorian inter-Andean region. The pathogenicity of the 30 isolates was determined by the mortality that they caused in larvae and adults and it was expressed in percentage; for this, a complete randomized design (CRD) was used. The LC50 and TL50 were determined by Probit analysis. The two selected isolates corresponded to: Metarhizium anisopliae (Metschnikoff 1879) Sorokin 1883 (A13) and  Beauveria bassiana (Bals.-Criv.) Vuill. 1912 (A21), which proved to be the best, because they caused the highest mortality in larvae of the fourth instar and adults of P. vorax. The Probit analysis showed that LC50 for A21 isolate (B. bassiana) in fourth instar larvae was obtained with a concentration of 1,75x109 spores/ml and 1,08x109 spores/ml for adults. Instead for A13 isolate (M. anisopliae), the LC50 was obtained with a concentration of 1,65x109 spores/ml for larvae and 2,42x109 spores/ml for adults. The LT50 for the selected isolates at the indicated concentrations, was 4,84 and 4,32 days for larvae with A13 and A21 isolates respectively, while, for adults, the shortest time was obtained with A21 isolate in 4.36 days, compared with A13 isolate, that delayed 20,70 days. The larval stage of P. vorax was the most susceptible to A13 isolate, on the other hand, larvae and adults were equally susceptible to A21 isolate at the indicated concentrations. According to the results obtained, the two selected isolates can be used as an alternative to the use of conventional agrochemicals, which will contribute to a more ecological production

    Teaching and learning musical instruments through ICT: the impact of the COVID-19 pandemic lockdown

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    The COVID-19 lockdown in education institutions required music teachers to use ICTto continue teaching. This research study, with the use of a Likert type online questionnaire, analyses the ICT activities carried out during this period and the learning conceptions they reflect. The questionnaire consisted of the description of activities which varied, depending on the learning promoted (reproductive or constructive), the learning outcomes (verbal, procedural, or attitudinal), the type of assessment to which the activities were directed, and the presence of cooperative activities. The teachers had to indicate the frequency with which they carried out these activities. The questionnaire was completed by 254 instrumental music teachers from different types of institutions and different levels. The main study outcome was that teachers used reproductive activities more frequently than constructive ones. We also found that most activities were those favouring verbal learning and assessment. The cooperative activities were the least frequent. Finally, through a cluster analysis, we identified three teaching profiles depending on the frequency and type of ICT used: Passive, Active, and Interpretative. The variable that produced the most consistent differences was previous ICT useThis work was supported by Ministerio de Ciencia e Innovacion of Spain (PID2020-114177RB-I00). Guadalupe Lopez- Iñiguez was also supported by the Senior Researcher grant “Expanding reflexivity of professional education in music in times of crises” awarded by the Jenny and Antti Wihuri Foundation in Finlan

    Toward integrated analysis of human impacts on forest biodiversity: lessons from Latin America.

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    Although sustainable forest management (SFM) has been widely adopted as a policy and management goal, high rates of forest loss and degradation are still occurring in many areas. Human activities such as logging, livestock husbandry, crop cultivation, infrastructural development, and use of fire are causing widespread loss of biodiversity, restricting progress toward SFM. In such situations, there is an urgent need for tools that can provide an integrated assessment of human impacts on forest biodiversity and that can support decision making related to forest use. This paper summarizes the experience gained by an international collaborative research effort spanning more than a decade, focusing on the tropical montane forests of Mexico and the temperate rain forests of southern South America, both of which are global conservation priorities. The lessons learned from this research are identified, specifically in relation to developing an integrated modeling framework for achieving SFM. Experience has highlighted a number of challenges that need to be overcome in such areas, including the lack of information regarding ecological processes and species characteristics and a lack of forest inventory data, which hinders model parameterization. Quantitative models are poorly developed for some ecological phenomena, such as edge effects and genetic diversity, limiting model integration. Establishment of participatory approaches to forest management is difficult, as a supportive institutional and policy environment is often lacking. However, experience to date suggests that the modeling toolkit approach suggested by Sturvetant et al. (2008) could be of value in such areas. Suggestions are made regarding desirable elements of such a toolkit to support participatory-research approaches in domains characterized by high uncertainty, including Bayesian Belief Networks, spatial multi-criteria analysis, and scenario planning.Most of the research described here was undertaken in three projects supported by the European Commission (INCO programme), namely SUCRE (ERBIC18CT970146), BIOCORES (ICA4- CT-2001-10095), and ReForLan (INCO-DEV-3 N° 032132), and three Darwin Initiative (DEFRA, UK Government) grants to the senior author. Additional funding was provided by a variety of sources within the partner countries. All sources of financial support are gratefully acknowledged

    Evidencia ultraestructural del nucléolo de Entamoeba histolytica

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    Although cell structure of Entamoeba histolytica is well known, the presence of nucleolar material has not been described with the electron microscope. Here we use light and electron microscopy cytochemical techniques to search for evidence1 of nucleolar material in this amoeba trophozoyte. Toluidine blue for RNA and silver staining for nucleolar organizer stain peripheral intranuclear material2. With the electron microscope, a3 similar material is fibro-granular and is contrasted with techniques for ribonucleoproteins and nucleolar organizer, but it is negative for DNA. These results show ultrastructural evidence for the presence of a peripheral and ring-shaped nucleolus4 in the nucleus of E. histolytica. It is suggested that this intranuclear organelle is a general feature in eukaryotes.Aunque la estructura celular de Entamoeba histolytica se conoce con detalle, no se ha descrito la presencia de material nucleolar con el microscopio electrĂłnico. En este trabajo utilizamos tĂ©cnicas citoquĂ­micas para microscopĂ­a de luz y electrĂłnica para evidenciar la presencia del nuclĂ©olo en trofozoitos de esta amiba. Con la tĂ©cnica de azul de toluidina para RNA y la tĂ©cnica de impregnaciĂłn argĂ©ntica para organizador nucleolar, se observa contraste de material intranuclear perifĂ©rico. Con el microscopio electrĂłnico, un  material similar de naturaleza fibro-granular se contrasta tambiĂ©n con las tĂ©cnicas para ribonucleoproteĂ­nas y para organizador nucleolar. Una zona similar es negativa cuando se aplican tĂ©cnicas para DNA. Estos resultados muestran evidencia ultraestructural de la presencia de un  nuclĂ©olo perifĂ©rico y anular en el nĂșcleo de E. histolytica. Se sugiere que este organelo intranuclear es un caracter general de los eucariontes

    EVIDENCIA ULTRAESTRUCTURAL DEL NUCLÉOLO DE Entamoeba histolytica

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    Aunque la estructura celular de Entamoeba histolytica se conoce con detalle, no se ha descrito la presencia de material nucleolar con el microscopio electrĂłnico. En este trabajo utilizamos tĂ©cnicas citoquĂ­micas para microscopĂ­a de luz y electrĂłnica para evidenciar la presencia del nuclĂ©olo en trofozoitos de esta amiba. Con la tĂ©cnica de azul de toluidina para RNA y la tĂ©cnica de impregnaciĂłn argĂ©ntica para organizador nucleolar, se observa contraste de material intranuclear perifĂ©rico. Con el microscopio electrĂłnico, un material similar de naturaleza fibro-granular se contrasta tambiĂ©n con las tĂ©cnicas para ribonucleoproteĂ­nas y para organizador nucleolar. Una zona similar es negativa cuando se aplican tĂ©cnicas para DNA. Estos resultados muestran evidencia ultraestructural de la presencia de un nuclĂ©olo perifĂ©rico y anular en el nĂșcleo de E. histolytica. Se sugiere que este organelo intranuclear es un caracter general de los eucariontes

    Race and sex differences in HDL peroxide content among American adults with and without type 2 diabetes

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    BackgroundHigh-density lipoprotein (HDL) plays a critical role in protection against atherosclerosic and cardiovascular disease (ASCVD). In addition to contributing to clearing excess vascular cholesterol, HDL particles exhibit antioxidative functions, helping to attenuate adverse effects of oxidized low-density lipoproteins. However, these beneficial properties can be undermined by oxidative stress, inflammation, and unhealthy lifestyles and diet, as well as influenced by race and sex. Thus, when assessing cardiovascular risk, it is important to consider multifactorial aspects of HDL, including antioxidant activity rather than just total amount and type of HDL-cholesterol (HDL-C) particles. Because prior research showed HDL peroxide content (HDLperox) can be inversely associated with normal anti-oxidant HDL activity, elevated HDLperox may serve as a bioindicator of HDL dysfunction.MethodsIn this study, data from a large national cohort of Americans was utilized to determine the impact of sex, race, and diabetes status on HDLperox in middle-aged and older adults. A previously developed cell-free fluorometric method was utilized to quantify HDLperox in serum depleted of apo-B containing lipoproteins.ResultsIn keeping with predictions, white men and diabetics exhibited HDLperox in the atypical upper range, suggestive of less functional HDL. White men had higher HDLperox levels than African American males (13.46 ± 6.10 vs. 10.88 ± 5.81, p < .001). There was also a significant main effect of type 2 diabetes (F(1,1901) = 14.9, p < .0001). Overall, African Americans evinced lower HDLperox levels, despite more obesity (10.3 ± 4.7 vs.11.81 ± 5.66 for Whites) suggesting that other aspects of lipid metabolism and psychosocial factors account for the higher prevalence of ASCVD in African Americans.ConclusionThis research helps to provide a more comprehensive understanding of HDL function in a racially and metabolically diverse adult population. HDLperox content was significantly different in adults with type 2 diabetes, and distinctive in nondiabetic White males, and suggests other processes account for the higher prevalence of ASCVD among African Americans

    Tripartite networks show that keystone species can multitask

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    Keystone species are disproportionately important for ecosystem functioning. While all species engage in multiple interaction types with other species, keystone species importance is often defined based on a single dimension of their Eltonian niche, that is, one type of interaction (e.g. keystone predator). It remains unclear whether the importance of keystone species is unidimensional or if it extends across interaction types. We conducted a meta-analysis of tripartite interaction networks examining whether species importance in one dimension of their niche is mirrored in other niche dimensions, and whether this is associated with interaction outcome, intimacy or species richness. We show that keystone species importance is positively associated across multiple ecological niche dimensions, independently of abundance, and find no evidence that multidimensionality of keystone species is influenced by the explanatory variables. We propose that the role of keystone species extends across multiple ecological niche dimensions, with important implications for ecosystem resilience and conservation. Read the free Plain Language Summary for this article on the Journal blog.Fil: TimĂłteo, SĂ©rgio. University Of Coimbra, Centre For Functional Ecology; PortugalFil: Albrecht, Jörg. Senckenberg BiodiversitĂ€t Und Klima Forschungszentrum; AlemaniaFil: Rumeu, Beatriz. Universidad de CĂĄdiz; EspañaFil: Norte, Ana C.. University Of Coimbra, Marine And Environmental Sciences Center; PortugalFil: Traveset, Anna. Consejo Superior de Investigaciones CientĂ­ficas. Instituto MediterrĂĄneo de Estudios Avanzados; EspañaFil: Frost, Carol M.. University of Alberta; CanadĂĄFil: Marchante, Elizabete. University Of Coimbra, Centre For Functional Ecology; PortugalFil: LĂłpez NĂșñez, Francisco A.. University Of Coimbra, Centre For Functional Ecology; PortugalFil: Peralta, Guadalupe. University of Canterbury; Nueva Zelanda. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Memmott, Jane. University Of Bristol; Reino UnidoFil: Olesen, Jens M.. University Aarhus; DinamarcaFil: Costa, JosĂ© M.. University Of Coimbra, Centre For Functional Ecology; PortugalFil: da Silva, LuĂ­s P.. Cibio - Centro de Investigação Em Biodiversidade E Recursos GenĂ©ticos; PortugalFil: Carvalheiro, LuĂ­sa G.. Universidade Federal de GoiĂĄs; Brasil. Universidade de Lisboa; PortugalFil: Correia, Marta. University Of Coimbra, Centre For Functional Ecology; PortugalFil: Staab, Michael. Universitat Technische Darmstadt; AlemaniaFil: BlĂŒthgen, Nico. Universitat Technische Darmstadt; AlemaniaFil: Farwig, Nina. Philipps-universitĂ€t Marburg; AlemaniaFil: HervĂ­as Parejo, Sandra. Consejo Superior de Investigaciones CientĂ­ficas. Instituto MediterrĂĄneo de Estudios Avanzados; EspañaFil: Mironov, Sergei. Zoological Institute Of The Russian Academy Of Sciences; RusiaFil: RodrĂ­guez EcheverrĂ­a, Susana. University Of Coimbra, Centre For Functional Ecology; PortugalFil: Heleno, Ruben. University Of Coimbra, Centre For Functional Ecology; Portuga
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