1,555 research outputs found
Proceraea exoryxae sp. nov. (Annelida, Syllidae, Autolytinae), the first known polychaete miner tunneling into the tunic of an ascidian
Este artículo contiene 25 páginas, 1 tabla, 7 figuras.While studying organisms living in association with the solitary tunicate Phallusia
nigra (Ascidiacea, Ascidiidae) from a shallow fringing reef at Zeytouna Beach
(Egyptian Red Sea), one of the collected ascidians showed peculiar perforations
on its tunic. Once dissected, the perforations revealed to be the openings of
a network of galleries excavated in the inner tunic (atrium) by at least six individuals
of a polychaetous annelid. The worms belonged to the Autolytinae (Syllidae),
a subfamily that is well known to include specialized predators and/or symbionts,
mostly associated with cnidarians. The Red Sea worms are here described as
Proceraea exoryxae sp. nov., which are anatomically distinguished by the
combination of simple chaetae only in anterior chaetigers, and a unique trepan with
33 teeth in one outer ring where one large tooth alternates with one medium-sized
tricuspid tooth, and one inner ring with small teeth located just behind the large
teeth.Male and female epitokes were found together with atokous individuals within
galleries. Proceraea exoryxae sp. nov. constitutes the first known miner in the
Autolytinae and the second species in this taxon known to live symbiotically with
ascidians. The implications of finding this specialized parasite are discussed
considering that Phallusia nigra has been introduced worldwide, in tropical and
sub-tropical ecosystems, where it has the potential of becoming invasive.EC-R was supported by a Faculty Improvement Grant from the American University in
Cairo. DM was supported by research project MarSymBiomics (grant number
CTM2013-43287-P) funded by the Ministerio de Educacio´ n, Cultura y Deporte, and by
the Consolidated Research Group on Marine Benthic Ecology (grant number
2014SGR120) of the Age`ncia de Gestio´ d’Ajuts Universitaris i de Recerca of the Generalitat
de Catalunya.Peer reviewe
DISTRIBUCIÓN DEL RECURSO HÍDRICO DE LA MICROCUENCA LA QUIÑA, DEPARTAMENTO DE BOYACÀ, COLOMBIA
La presente investigación se realizó entre la Universidad de Pamplona y (CORPOCHIVOR), con el objeto es determinar la oferta y demanda hídrica de la microcuenca Q. La Quiña, departamento de Boyacá, para realizar la distribución de agua con base en los usos del recurso, teniendo en cuenta la normativa ambiental. Se aplicaron las metodologías citadas en la Resolución 865 del 22 de Julio 2004 y el Estudio Nacional del Agua (ENA) 2010 para determinar el índice de escasez de agua. La cartografía de la zona de estudio fue proporciona por el SIAT de CORPCHIVOR, y complementada con el levantamiento de información en campo. Los programas utilizados para la determinación de la ETP es el CROPWAT 8.0 (FAO) y para los análisis estadísticos el paquete Excel
An ACO-based Hyper-heuristic for Sequencing Many-objective Evolutionary Algorithms that Consider Different Ways to Incorporate the DM's Preferences
Many-objective optimization is an area of interest common to researchers, professionals, and practitioners because of its real-world implications. Preference incorporation into Multi-Objective Evolutionary Algorithms (MOEAs) is one of the current approaches to treat Many-Objective Optimization Problems (MaOPs). Some recent studies have focused on the advantages of embedding preference models based on interval outranking into MOEAs; several models have been proposed to achieve it. Since there are many factors influencing the choice of the best outranking model, there is no clear notion of which is the best model to incorporate the preferences of the decision maker into a particular problem. This paper proposes a hyper-heuristic algorithm—named HyperACO—that searches for the best combination of several interval outranking models embedded into MOEAs to solve MaOPs. HyperACO is able not only to select the most appropriate model but also to combine the already existing models to solve a specific MaOP correctly. The results obtained on the DTLZ and WFG test suites corroborate that HyperACO can hybridize MOEAs with a combined preference model that is suitable to the problem being solved. Performance comparisons with other state-of-the-art MOEAs and tests for statistical significance validate this conclusion
Identification and functional analysis of novel phosphorylation sites in the RNA surveillance protein Upf1.
One third of inherited genetic diseases are caused by mRNAs harboring premature termination codons as a result of nonsense mutations. These aberrant mRNAs are degraded by the Nonsense-Mediated mRNA Decay (NMD) pathway. A central component of the NMD pathway is Upf1, an RNA-dependent ATPase and helicase. Upf1 is a known phosphorylated protein, but only portions of this large protein have been examined for phosphorylation sites and the functional relevance of its phosphorylation has not been elucidated in Saccharomyces cerevisiae. Using tandem mass spectrometry analyses, we report the identification of 11 putative phosphorylated sites in S. cerevisiae Upf1. Five of these phosphorylated residues are located within the ATPase and helicase domains and are conserved in higher eukaryotes, suggesting a biological significance for their phosphorylation. Indeed, functional analysis demonstrated that a small carboxy-terminal motif harboring at least three phosphorylated amino acids is important for three Upf1 functions: ATPase activity, NMD activity and the ability to promote translation termination efficiency. We provide evidence that two tyrosines within this phospho-motif (Y-738 and Y-742) act redundantly to promote ATP hydrolysis, NMD efficiency and translation termination fidelity
Cell dedifferentiation and epithelial to mesenchymal transitions during intestinal regeneration in H. glaberrima
<p>Abstract</p> <p>Background</p> <p>Determining the type and source of cells involved in regenerative processes has been one of the most important goals of researchers in the field of regeneration biology. We have previously used several cellular markers to characterize the cells involved in the regeneration of the intestine in the sea cucumber <it>Holothuria glaberrima</it>.</p> <p>Results</p> <p>We have now obtained a monoclonal antibody that labels the mesothelium; the outer layer of the gut wall composed of peritoneocytes and myocytes. Using this antibody we studied the role of this tissue layer in the early stages of intestinal regeneration. We have now shown that the mesothelial cells of the mesentery, specifically the muscle component, undergo dedifferentiation from very early on in the regeneration process. Cell proliferation, on the other hand, increases much later, and mainly takes place in the mesothelium or coelomic epithelium of the regenerating intestinal rudiment. Moreover, we have found that the formation of the intestinal rudiment involves a novel regenerative mechanism where epithelial cells ingress into the connective tissue and acquire mesenchymal phenotypes.</p> <p>Conclusions</p> <p>Our results strongly suggest that the dedifferentiating mesothelium provides the initial source of cells for the formation of the intestinal rudiment. At later stages, cell proliferation supplies additional cells necessary for the increase in size of the regenerate. Our data also shows that the mechanism of epithelial to mesenchymal transition provides many of the connective tissue cells found in the regenerating intestine. These results present some new and important information as to the cellular basis of organ regeneration and in particular to the process of regeneration of visceral organs.</p
Establishing a governance threshold in small-scale fisheries to achieve sustainability
The lack of effective governance is a major concern in small-scale fisheries. The implementation of governance that encompasses the three pillars of sustainability (social, economic, and ecological) is still a worldwide challenge. We examined nine stalked barnacle fisheries (Pollicipes pollicipes) across Southwest Europe to better understand the relationship between governance elements and sustainability. Our results show that nested spatial scales of management, the access structure, co- management, and fisher’s participation in monitoring and surveillance promote sustainability. However, it is not the mere presence of these elements but their level of implementation that drives sustainability. Efforts should be placed in the accomplishment of a minimum combination of local scales of management, access rights through individual quotas, instructive-consultative co- management and functional participation. Surpassing this threshold in future governance structures will start to adequately promote social, economic and ecologically sustainability in small-scale fisheries
Situation, challenges, and SEOM recommendations for the future of undergraduate education in Oncology in Spain
Purpose The Spanish Society of Medical Oncology (SEOM, for its Spanish acronym) would like to attest to the relevance
of training in Oncology as part of the undergraduate education in Medicine program and issue recommendations to improve
said training, with the aim of responding better to the challenges that cancer poses to our society.
Materials and methods The curricula of 42 schools of medicine were reviewed with interviews with at least one teaching
medical oncologist from each faculty. The qualitative and opinion analysis was completed by means of an online questionnaire
targeting lecturers, resident tutors, and residents in Medical Oncology (MO), enabling the detection of needs and areas
for improvement at an organizational level and in terms of skill acquisition.
Results While the number of medical schools with a specific, mandatory program in MO has grown by up to 90%, it has
not been accompanied by an increase in independent programs. Instead, they largely consist of programs shared with other
specialties (61% of the medical faculties). In most of the undergraduate education programs, Oncology contents are fragmented
and approached from the perspective of each organ system.
Conclusions Despite the positive evolution in recent years, the heterogeneity in Oncology contents during undergraduate
education training continues to be remarkable. Cross-sectional programs with an integral vision, taught in the final years of
undergraduate medical education would be desirable. Among the recommendations for improvement of training in Medical
Oncology, the SEOM proposes that updated, theoretical content be incorporated and clinical practice in Medical Oncology departments be promotedThis study was funded as an unrestricted grant by Jansse
- …