611 research outputs found
Patrón espacial de la variación molecular de Apis mellifera en Gran Canaria y la Gomera (Islas Canarias)
Las islas del Archipiélago Canario presentan condiciones ambientales variables según
su altitud, latitud y longitud, lo cual influye en la distribución de los organismos. En
relación con la abeja de la miel (Apis mellifera L.), estudios previas realizados por De la
Rúa et a I. ( 1998) Y por Padilla-Álvarez et al. (1998), sugieren la existencia en las Islas
Canarias de poblaciones que han evolucionado de una forma relativamente aislada y
que se han adaptado en cada isla a unas determinadas condiciones ambientales. Las
abejas canarias fueron incluí das en un sublinaje de distribución atlántica (AIII) del
linaje evolutivo africano, en el cual se circunscriben las poblaciones de abejas de los
Archipiélagos Maearonésicos (Islas Azores, Madeira, Islas Salvajes, Islas Canarias y
Cabo Verde) y de Portugal. En el presente trabajo se presentan los resultados del estudio
de la variabilidad molecular al nivel mitocondrial (ADNmt), de las poblaciones de
abejas de la miel en las islas canarias de Gran Canaria y La Gomera mediante el análisis
de la región intergénica del ADNmt comprendida entre los genes del ARN transferente
de la leucina (ARNtleu) y la subunidad II de la citocromo oxidasa (cox2). Este
marcador es adecuado para estimar la diversidad genética y los patrones de
diferenciación espacial, en relación con la variedad ambiental existente en las islas de
Gran Canaria y La Gomera
The atlantic side of the iberian peninsula: a hot-spot of novel maternal honey bee diversity
The Iberian Peninsula harbors one the highest mitocondrial DNA (mtDNA) diversity ever reported for honey bee subspecies. This finding is explained not only by the co-occurrence of two divergent evolutionary lineages, western European (lineage M) and African (lineage A), but also by the higher variability of African and western European haplotypes. Indeed, over 36 haplotypes of western European and African ancestry, which form complex networks, have been reported for this area of the honey bee natural range. While studies on the diversity patterns of central and Mediterranean Iberian populations are abundant, the genetic composition of populations inhabiting the Atlantic side was until recently virtually unknown. Using the popular DraI test (PCR amplification and restriction of the intergenic tRNAleu-coxII region) we performed a fine scale genetic survey of the honey bee populations from Portugal. Adding to the 24 previously described African haplotypes, of which 17 are found in the Iberian Peninsula, 13 unreported haplotypes of African ancestry were found in our survey, which represent an addition of 54% of new variation. The fragment sizes ranged from approximately 800 to 1200 bp and the restriction length of the new haplotypes were very distinct from those reported in the literature. To further confirm the novelty of these haplotypes, we sequenced the aforementioned mtDNA region. Herein we present a phylogenetic analysis of these novel haplotypes
“Aging in Displacement: Urban Revitalization and Puerto Rican Elderhood in Chicago”
Displacement has marked the individual and collective lives of Puerto Ricans in Chicago, especially those who migrated in the 1950s and 1960s. For these older persons, the arrival of the gentry and the yuppies of yesterday, the hipsters of today, and the disappearance of familiar faces in their current neighborhoods are not new phenomena, but rather parts of a profoundly familiar process. They came of age in displacement. Today some Puerto Rican older adults have achieved housing security and are able to age in place because they live in low-income senior housing. Yet a sense of displacement still looms large in their daily lives with the upscaling of and new-build gentrification in their current neighborhood. This work sheds light on the meaning of place for older adult Puerto Ricans who have experienced what psychiatrist and urban studies scholar Mindy T. Fullilove calls a history of “serial displacement.” Through life history narratives and ethnographic snapshots, this paper highlights the neglected reality of “aging in displacement,” or the experience of growing up and growing older in a context of repeated socio-spatial dislocation and how individual and collective life histories of community upheaval texture the spatial and social meanings of place
Polymorphisms in cytochrome P450 versus cline distribution of evolutionary lineages in Apis mellifera iberiensis
Honey bees (Apis mellifera) are the most prominent and economically important pollinator species worldwide. However, the reported decline of its populations in several regions of the world over the last decades is of concern. The causes are manifold, including the spread of pathogens and parasites, malnutrition and habitat loss, climate change and xenobiotics, especially pesticides. Among the main mechanisms used by insects to cope with the adverse effects of xenobiotics is the metabolic resistance mediated mainly by three superfamilies of enzymes: the cytochrome P450 monooxygenases, the glutathione transferases and the carboxylesterases.
We hypothesize that the genetic background influences the sensitivity to pesticides or detoxification capacity of different honey bee populations, ecotypes and subspecies. The Iberian Peninsula provides an interesting scenario to study the genetic variability of the cytochrome P450 genes given the co-occurrence of two clinally distributed evolutionary lineages, as a result of secondary contact.
In this study, the genetic variability of six genes of the cytochrome P450 superfamily (CYP6AS3, CYP6AS4, CYP6AS5, CYP6AS7, CYP6AS12 and CYP6AS17) was analyzed in the Iberian honey bee (Apis mellifera iberiensis) to provide more information on the mechanisms of resistance to xenobiotics and to identify the genetic variation involved in local adaptation. Genomic signal of selective sweeps was detected in three genes, of which CYP6AS5 presents the highest number of point mutations under selection, being proposed as a candidate gene to perform gene expression studies. We discuss the correlation between the variability of P450 genes and the distribution of the evolutionary lineages in the Iberian Peninsula. The identification of polymorphisms in these genes promises to shed light on the relationship between diversity and xenobiotic tolerance of A. m. iberiensis.info:eu-repo/semantics/publishedVersio
Creating functional nanostructures: Encapsulation of caffeine into α-lactalbumin nanotubes
This work evaluated the stability and functionality of nanotubes obtained from α-lactalbumin (α-LA). α-LA nanotubes' structure was highly stable during a freeze-drying process but not after grinding. The ability of α-LA nanotubes to encapsulate caffeine, used as a model molecule, was evaluated. α-La nanotubes were highly effective for this purpose as encapsulation efficiency (%EE) was near 100% and loading capacity (%LC) near 10% at 1.5/20 and 2/20 ratios (caffeine/α-LA, w/w). α-LA nanotubes' structure was not affected by the presence of caffeine. Also, in general, refrigeration temperatures and neutral or alkaline conditions, under which the adverse effect of chelating agents was prevented, helped to stabilise α-LA nanotubes' structure and maintain caffeine encapsulated. At 8 °C and pH 7.5, in the presence of 75 μg mL− 1 of EDTA, > 50% of the caffeine remained encapsulated into α-LA nanotubes.Clara Fuciños gratefully acknowledge her Post-Doctoral grant (I2C 2014) from Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia, Spain). Pablo Fuciños gratefully acknowledges his Marie Curie COFUND Postdoctoral Research Fellowship (Project No: 600375. NanoTRAINforGrowth - INL Fellowship programme in nanotechnologies for biomedical, environment and food applications). This study was supported by the Fundação para a Ciência e a Tecnologia (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)
Las prácticas de enseñanza de los docentes de Matemática en la educación secundaria
El artículo presenta los resultados de la investigación llevada a cabo desde la Universidad Católica de Córdoba entre 2016 y 2018 con el propósito de caracterizar cómo son las prácticas de enseñanza de los docentes de Matemática en la educación secundaria, a partir de la observación de sus clases; estos resultados están organizados en diez aspectos seleccionados como descriptores privilegiados, cada uno de los cuales está representado por porcentajes de preeminencia y por testimonios que operan como estampas.PALABRAS CLAVE: Prácticas de enseñanza; Didáctica de la Matemática; Enseñanza de la Matemática; Enseñanza en la escuela secundaria; Didáctica específica de la Matemática; Didáctica Específica de la Educación Secundaria.Teaching practices of mathematics teachers in secondary educationABSTRACTThe article presents the results of the research carried out from the Catholic University of Córdoba between 2016 and 2018 with the purpose of characterizing the teaching practices of Mathematics teachers in Middle and High School, based on observation of their classes; these results are organized into ten selected aspects as privileged descriptors, each of which is represented by percentages of preeminence and by testimonies that operate as stamps.KEYWORDS: Teaching practices; Teaching of Mathematics; Teaching in Middle and High School; Specific Didactics of the Mathematics; Specific Didactics of Middle and High School.
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