1,672 research outputs found
Los pingüinos de la región de Magellanes
The Magellan region, including the Falkland Islands, is one of the world´s most important areas for seabirds, and especially penguins. World-wide there are 17 species of penguin; 7 of these regularly breed around the coastal waters of South America, and 5 within the Magellan region. These are the King Penguin (Aptenodytes patagonicus), Gentoo Penguin (Pygoscelis papua), Rockhopper Penguin (Eudyptes c. chrysocome), Macaroni Penguin (Eudyptes chrysolophus) and Magellanic Penguin (Spheniscus magellanicus). During the last five years, a review of the breeding populations of penguins within the Magellan region was conducted. This work included population censuses of all the surface breeding species throughout the Falkland Islands and southern South America. The results of this work are presented, along with other cited information, to provide a summary of the current knowledge of penguin populations within the Magellan region.La región de Magallanes, incluyendo las Islas Falkland, es un área muy importante para las aves marinas del mundo. Hay 17 especies de pingüinos; 7 crían en América del Sur y 5 crían en la región de Magallanes. Se trata de los Pingüino Rey (Aptenodytes patagonicus), Pingüino Papúa (Pygoscelis papua), Pingüino de Penacho Amarillo (Eudyptes c. chrysocome), Pingüino Macaroni (Eudyptes chrysolophus) y Pingüino de Magallanes (Spheniscus magellanicus). Durante los últimos 5 años investigamos las poblaciones de los pingüinos en la región de Magallanes. Esta investigación incluyó registros de todas las especies que crían sobre la tierra en las Islas Falkland y en el extremo meridional de América del Sur. Presentamos nuestros resultados con información de otra literatura citada para proporcionar un resumen del conocimiento sobre las poblaciones de los pingüinos en la región de Magallanes
Gluten Detection Methods and Their Critical Role in Assuring Safe Diets for Celiac Patients
Celiac disease, wheat sensitivity, and allergy represent three different reactions, which may occur in genetically predisposed individuals on the ingestion of wheat and derived products with various manifestations. Improvements in the disease diagnostics and understanding of disease etiology unveiled that these disorders are widespread around the globe affecting about 7% of the population. The only known treatment so far is a life-long gluten-free diet, which is almost impossible to follow because of the contamination of allegedly “gluten-free” products. Accidental contamination of inherently gluten-free products could take place at any level from field to shelf because of the ubiquity of these proteins/grains. Gluten contamination of allegedly “gluten-free” products is a constant threat to celiac patients and a major health concern. Several detection procedures have been proposed to determine the level of contamination in products for celiac patients. The present article aims to review the advantages and disadvantages of different gluten detection methods, with emphasis on the recent technology that allows identification of the immunogenic-gluten peptides without the use of antibodies. The possibility to detect gluten contamination by different approaches with similar or better detection efficiency in different raw and processed foods will guarantee the safety of the foods for celiac patients
A window into the human immune system:comprehensive characterization of the complexity of antibody complementary-determining regions in functional antibodies
The human immune system uses antibodies to neutralize foreign antigens. They are composed of heavy and light chains, both with constant and variable regions. The variable region has six hypervariable loops, also known as complementary-determining regions (CDRs) that determine antibody diversity and antigen specificity. Knowledge of their significance, and certain residues present in these areas, is vital for antibody therapeutics development. This study includes an analysis of more than 11,000 human antibody sequences from the International Immunogenetics information system (IMGT). The analysis included parameters such as length distribution, overall amino acid diversity, amino acid frequency per CDR and residue position within antibody chains. Overall, our findings confirm existing knowledge, such as CDRH3‘s high length diversity and amino acid variability, increased aromatic residue usage, particularly tyrosine, charged and polar residues like aspartic acid, serine, and the flexible residue glycine. Specific residue positions within each CDR influence these occurrences, implying a unique amino acid type distribution pattern. We compared amino acid type usage in CDRs and non-CDR regions, both in globular and transmembrane proteins, which revealed distinguishing features, such as increased frequency of tyrosine, serine, aspartic acid, and arginine. These findings should prove useful for future optimization, improvement of affinity, synthetic antibody library design, or the creation of antibodies de-novo in silico.</p
Carotenoid skin ornaments as flexible indicators of male foraging behavior in a marine predator: Variation among Mexican colonies of brown booby ( Sula leucogaster )
Carotenoid-dependent ornaments can reflect animals’ diet and foraging behaviors. However, this association should be spatially flexible and variable among populations to account for geographic variation in optimal foraging behaviors. We tested this hypothesis using populations of a marine predator (the brown booby, Sula leucogaster) that forage across a gradient in ocean depth in and near the Gulf of California. Specifically, we quantified green chroma for two skin traits (foot and gular color) and their relationship to foraging location and diet of males, as measured via global positioning system tracking and stable carbon isotope analysis of blood plasma. Our three focal colonies varied in which foraging attributes were linked to carotenoid-rich ornaments. For gular skin, our data showed a shift from a benthic prey-green skin association in the shallow waters in the north to a pelagic prey-green skin association in the deepest waters to the south. Mean foraging trip duration and distance of foraging site from coast also predicted skin coloration in some colonies. Finally, brown booby colonies varied in which trait (foot versus gular skin color) was associated with foraging metrics. Overall, our results indicate that male ornaments reflect quality of diet and foraging–information that may help females select mates who are adapted to local foraging conditions and therefore, are likely to provide better parental care. More broadly, our results stress that diet-dependent ornaments are closely linked to animals’ environments and that we cannot assume ornaments or ornament signal content are ubiquitous within species, even when ornaments appear similar among populations
ERP evidence suggests executive dysfunction in ecstasy polydrug users
Background: Deficits in executive functions such as access to semantic/long-term memory have been shown in ecstasy users in previous research. Equally, there have been many reports of equivocal findings in this area. The current study sought to further investigate behavioural and electro-physiological measures of this executive function in ecstasy users.
Method: Twenty ecstasy–polydrug users, 20 non-ecstasy–polydrug users and 20 drug-naïve controls were recruited. Participants completed background questionnaires about their drug use, sleep quality, fluid intelligence and mood state. Each individual also completed a semantic retrieval task whilst 64 channel Electroencephalography (EEG) measures were recorded.
Results: Analysis of Variance (ANOVA) revealed no between-group differences in behavioural performance on the task. Mixed ANOVA on event-related potential (ERP) components P2, N2 and P3 revealed significant between-group differences in the N2 component. Subsequent exploratory univariate ANOVAs on the N2 component revealed marginally significant between-group differences, generally showing greater negativity at occipito-parietal electrodes in ecstasy users compared to drug-naïve controls. Despite absence of behavioural differences, differences in N2 magnitude are evidence of abnormal executive functioning in ecstasy–polydrug users
Kinetic modelling of competition and depletion of shared miRNAs by competing endogenous RNAs
Non-conding RNAs play a key role in the post-transcriptional regulation of
mRNA translation and turnover in eukaryotes. miRNAs, in particular, interact
with their target RNAs through protein-mediated, sequence-specific binding,
giving rise to extended and highly heterogeneous miRNA-RNA interaction
networks. Within such networks, competition to bind miRNAs can generate an
effective positive coupling between their targets. Competing endogenous RNAs
(ceRNAs) can in turn regulate each other through miRNA-mediated crosstalk.
Albeit potentially weak, ceRNA interactions can occur both dynamically,
affecting e.g. the regulatory clock, and at stationarity, in which case ceRNA
networks as a whole can be implicated in the composition of the cell's
proteome. Many features of ceRNA interactions, including the conditions under
which they become significant, can be unraveled by mathematical and in silico
models. We review the understanding of the ceRNA effect obtained within such
frameworks, focusing on the methods employed to quantify it, its role in the
processing of gene expression noise, and how network topology can determine its
reach.Comment: review article, 29 pages, 7 figure
Actividad invernal de Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) en las Vegas del Guadiana (Extremadura)
[ESP] El trips F. occidentalis es capaz de reproducirse a lo largo de todo el año, sin periodo de diapausa invernal, en las regiones mediterráneas de la geografía peninsular, caracterizadas por inviernos temperados (cf. costas de Levante), precisamente donde más
problemas ocasiona, por si mismo o en conjunción con el TSWV. Al contrario, en las
regiones de clima continental, con inviernos rigurosos, son sólo los adultos diapausantes
los que perpetúan la especie (cf. centro peninsular). Para clarificar esta situación en las Vegas del Guadiana (Extremadura), con un clima transicional entre ambos extremos,
se estudió la actividad invernal de F. occidentalis durante los inviernos de
1995/1996 y 1996/1997. La dinámica poblacional se siguió mediante el muestreo sistemático de 30 brotes de alfalfa cada 1-2 semanas y extracción en embudo de Berlese-
Tullgren. Paralelamente, se efectuó un muestreo de la vegetación adventicia y un seguimiento del vuelo de los adultos con trampas cromáticas.
Se observó una situación antagónica entre ambos inviernos. Durante el invierno de
1995/1996, aunque F. occidentalis disminuyó sus efectivos, tuvo lugar una presencia
continuada de larvas, evidenciando que el trips no entró en diapausa y fue capaz de reproducirse.
Al contrario, durante el invierno de 1996/1997, F. occidentalis entró en
diapausa y detuvo su reproducción, detectándose larvas tan sólo muy esporádicamente.
La confrontación de las temperaturas de ambos inviernos con las del año medio, indica
que la situación más usual en las Vegas del Guadiana debe corresponderse con la observada
en 1996/1997, aunque la gran variabilidad térmica invernal interanual que caracteriza
a la zona, especialmente patente en los últimos años, también sugiere que la
reproducción invernal de F. occidentalis en las Vegas del Guadiana no debe ser infrecuente.
El trips se asoció a 10 de las 13 especies de malas hierbas invernales muestreadas,
que confirmaron su papel como reservorio potencial de insectación. El empleo de
trampas cromáticas no fue efectivo para el seguimiento de las poblaciones de adultos
durante el invierno.
Se sugiere que las temperaturas invernales pueden ser un factor determinante de la
irregular incidencia del complejo F. occidentalis-JSWW constatada en las Vegas del
Guadiana.
[ENG] The western flower thrips F. occidentalis does not enter in diapause and maintains its reproduction throughout the winter in temperate areas of Spain, precisely where more damage produces itself or together with the TSWV. In the contrary, in cold winter continental areas the thrips overwinters as diapausing adult. To clarify this situation in the Vegas del Guadiana, Extremadura, southwestern Spain, with a transitional climate between both extremes, the winter activity of F. occidentalis was studied during 1995/1996 and 1996/1997. Thrips population dynamic was monitored sampling systematically
30 lucerne shoots every 1-2 weeks and extracting thrips with a Berlese-Tullgren
funnel. Additionally, population dynamic was monitored on winter weeds and
with chromatic sticky traps.
An opposed situation was observed between both winters. During 1995/1996 winter,
even though F. occidentalis population was limited, larvae occurred throughout the
winter, pointing out that F. occidentalis did not enter in diapause and maintained reproduction.
In the contrary, during 1996/1997 winter, larvae were detected only very sporadically,
which suggests that thrips reproduction was stopped and adult diapause induced.
The comparison of temperatures of both winters with mean-year temperatures, indicates that the usual situation in the Vegas del Guadiana could be the observed during 1996/1997, even though the high winter thermic inter-annual variation that characterizes the region, specially in the last years, also suggests that thrips winter reproduction may be frequent. F. occidentalis occurred on 10 of 13 species of weeds sampled, which confirms their role as potential reservoir to infest crops. Sticky traps were no effective for monitoring adult populations during the winter.
It is suggested that winter temperature may be an important factor determining the
observed irregular incidence of the F. occidentalis-TSWV complex in the Vegas del
Guadiana
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