Search results for "Bulos"
showing 10 items of 48 documents
Preferential assimilation of seagrass detritus by two coexisting Mediterranean sea cucumbers: Holothuria polii and Holothuria tubulosa
2019
Abstract Holothuria polii and Holothuria tubulosa are two of the most commercially exploited sea cucumbers of the Mediterranean Sea. As deposit-feeders, they represent an important component of the benthic community. Hence, knowledge of their feeding behaviour is crucial for understanding their function in terms of benthic ecology and sediment dynamics. Using information obtained from stable isotope analysis, the food selectivity/assimilation, temporal variations in diet and trophic niche of H. polii and H. tubulosa were investigated. Analysis of carbon and nitrogen isotopic ratios in body wall tissue showed a preferential assimilation of seagrass detritus among multiple food sources, with …
Cytotoxic activity of Holothuria tubulosa (Echinodermata) coelomocytes.
2017
Abstract The immune system of marine invertebrates, in particular that of holothurians, still requires further study. Our research showed that coelomocyte cells contained in the coelomic fluid of the sea cucumber, Holothuria tubulosa, are able to lyse, in vitro, red blood cells in rabbits and sheep. A plaque-forming assay showed spherule cells to be the effector cells, able to release cytotoxic molecules after xenogenic cell contact. The coelomocyte lysate supernatant, analysed by polyacrylamide gel electrophoresis overlay technique, using rabbit and sheep erythrocytes, showed two different haemolytic protein patterns: one calcium dependent and the other calcium independent. The fractions o…
Cytotoxic Potential of the Coelomic Fluid Extracted from the Sea Cucumber Holothuria tubulosa against Triple-Negative MDA-MB231 Breast Cancer Cells
2019
Growing evidence has demonstrated that the extracts of different holothurian species exert beneficial effects on human health. Triple negative breast cancers (TNBC) are highly malignant tumors that present a poor prognosis due to the lack of effective targeted therapies. In the attempt to identify novel compounds that might counteract TNBC cell growth, we studied the effect of the exposure of the TNBC cell line MDA-MB231 to total and filtered aqueous extracts of the coelomic fluid obtained from the sea cucumber Holoturia tubulosa, a widespread species in the Mediterranean Sea. In particular, we examined cell viability and proliferative behaviour, cell cycle distribution, apoptosis, autophag…
Search for high energy cosmic muon neutrinos from variable gamma-ray sources and time calibration of the optical modules of the ANTARES telescope
2015
325 páginas. Tesis Doctoral del Departamento de Física Atómica, Molecular y Nuclear de la Universidad de Valencia y del Instituto de Física Corpuscular (IFIC).
Calvin-Benson Cycle
2015
A carbon dioxide fixation pathway where a molecule of CO2 condenses with a 5-C compound (ribulose 1,5-bisphosphate) to yield two molecules of a 3-C compound (3-phosphoglycerate). These 3-C molecules serve both as precursors for biosynthesis and, through a cyclic series of enzymatic reactions, to regenerate the 5-C molecule necessary for the first carboxylating step (Fig. 1). The pathway is present in several bacterial lineages (e.g., cyanobacteria), and its acquisition by eukaryotic cells (chloroplast in algae and plants) was through the endosymbiotic association with ancient cyanobacteria.
Tipología y patrones de los bulos difundidos durante la pandemia de la covid-19 sobre salud y nutrición
2022
This study aims to identify the typology and patterns of hoaxes related to health and nutrition disseminated during the first stage of the COVID-19 pandemic (March-November 2020). To do this, an exploratory quantitative study was carried out with two data types. The first data comes from studying 95 documents (scientific articles) found in the SCOPUS database through Boolean searches with the terms (dis)misinformation, hoax, health, and nutrition. A registration form was used for these documents, indicating the following items: a) topic of the article (health or nutrition); b) the type of wrong message (misinformation or hoax); c) the country in which the study was done; d) the type of part…
Echinoderm Antimicrobial Peptides
2016
Abstract Antimicrobial peptides (AMPs) are widely expressed in organisms and have been linked to innate and acquired immunity in vertebrates. These compounds are constitutively expressed from different cellular types to interact directly with infectious agents and/or modulate immunoreactions. In invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system, AMPs represent the major humoral defense system against infection, showing a diverse spectrum of action mechanisms, most of them related to plasma membrane disturbance and lethal alteration of microbial integrity. Here, we summarize the knowledge of AMPs in echinoderms as Strongylocins identified in the sea ur…
Structural and functional characterization of a transcription-enhancing sequence element in the rbcL gene of the Chlamydomonas chloroplast genome.
2002
The structure and function of a transcription-enhancing sequence element in the coding region of the Chlamydomonas reinhardtii rbcL gene was analyzed in Chlamydomonas chloroplast transformants in vivo. The enhancer sequence is contained within a DNA segment extending from position +108 to position +143, relative to the start site of rbcL gene transcription. The sequence remains functional when inverted or when placed 34 bp closer to or 87 bp further downstream of the basic rbcL promoter. However, it does not function from a site about 250 bp downstream of its original location. Besides promoting transcription initiation from the rbcL promoter, the element is able to augment transcription fr…
Short duplication in a cDNA clone of the rbcL gene from Picea abies.
1995
The plastidic rbcL gene encodes the LSU of Rubisco (EC 4.1.1.39), the enzyme that catalyzes CO, fixation during photosynthesis (Hallick and Bottomley, 1983). In higher plants the enzyme structure is commonly given as a hexadecameric structure composed of eight LSUs and eight small subunits. Nucleotide sequence data from the rbcL gene have been used extensively in studies of plant phylogeny and molecular evolution (Morden and Golden, 1991; Pasternak and Glick, 1992). To investigate the expression of the rbcL gene in damaged and undamaged Norway spruce trees (Picea abies), we have isolated a rbcL cDNA clone via reverse transcriptasePCR (Table I). Using the proofreading ability of the DNA poly…
Specific roles of 5′ RNA secondary structures in stabilizing transcripts in chloroplasts
2005
RNA secondary structures, e.g. stem-loops that are often found at the 5' and 3' ends of mRNAs, are in many cases known to be crucial for transcript stability but their role in prolonging the lifetime of transcripts remains elusive. In this study we show for an essential RNA-stabilizing stem-loop at the 5' end of rbcL gene transcripts in Chlamydomonas that it neither prevents ribonucleases from binding to the RNA nor impedes their movement along the RNA strand. The stem-loop has a formative function in that it mediates folding of a short sequence around its base into a specific RNA conformation, consisting of a helical and single-stranded region, i.e. the real structure required for longevit…