392 research outputs found
Effects of date palm fruit extracts on skin mucosal immunity, immune related genes expression and growth performance of common carp (Cyprinus carpio) fry
The aim of this study was to investigate the effects of date palm fruit extracts (DPFE) on skin mucosal immunity, immune related genes expression and growth performance of fry common carp (Cyprinus carpio). One hundred and twenty specimens (4.06 ± 0.13 g) were supplied and allocated into six aquaria; specimens in three aquaria were fed non-supplemented diet (control) while the fish in the other 3 aquaria were fed with DPFE at 200 ml kg-1. At the end of feeding trial (8 weeks) skin mucus immune parameters (total immunoglobulins, lysozyme, protease and alkaline phosphatase activity) and immune related gene expression (tumor necrosis factor α [tnfa], lysozyme [ly] and interleukin-1-beta, [il1b]) in the head-kidney were studied. The results revealed that feeding carp fry with 200 ml kg-1 DPFE remarkably elevated the three skin mucus immune parameters tested (P 0.05) compared to control fish (fed control diet). Furthermore, growth performance parameters were significantly improved in fry fed DPFE (P < 0.05). More studies are needed to understand different aspects of DPFE administration in fry mucosal immunity. © 2015 Elsevier Ltd
The Rural Digital Divide in the Face of the COVID-19 Pandemic in Europe-Recommendations from a Scoping Review
The COVID-19 pandemic has revealed the digital vulnerability of many citizens of the rural world. This article identifies and analyzes the proposals made by academic literature to overcome the digital divide in the European rural world for the five-year period 2016-2020. A scoping review has been carried out according to the PRISMA methodology in the two dimensions of the digital divide: access and connectivity, and use and exploitation. Online databases were used to identify scientific articles from which, after screening, 28 key documents were selected. The results update Salemink systematic review of articles published between 1991 and 2014 on digital and rural development in Western countries and it also intends to go beyond by extracting recommendations. A variety of political, social, educational, technical and economic issues has been exposed, with a common emphasis on the empowerment of rural populations. The findings provide actionable evidence and proposals to facilitate decision-making in current policy information to overcome rural digital divide. From them, seven recommendations that could have a wide and rapid impact to minimize the effects of the COVID-19 pandemic linked to the rural digital divide are synthesized. Three lines of action in the medium term are also proposed: the evaluation of national and regional public policies; the consideration of digital inclusion as a potential instrument to reduce rural depopulation; and the training in advanced digital skills to improve the social communication processes, considered key to promote empowerment and entrepreneurship
Propuesta de un modelo de Sistema Integrado de Gestión de la Información Documental para las organizaciones
Se presenta un modelo de sistema integrado de gestión de la información documental para las organizaciones con un enfoque de gestión orientado a procesos, basado en el análisis de la literatura científica y el estudio de caso de tres organizaciones empresariales. Se exponen los principios conceptuales y operativos que fundamentan el sistema de información. Se indican los objetivos, los componentes y la estructura de los subsistemas comunes a todo sistema integrado. Se describe la metodología de diseño, planificación y evaluación del sistema, compuesta de seis etapas. Se concluye que esta propuesta puede servir de base para la elaboración de unas directrices de aplicación en cualquier organización por parte de una institución normalizadora o reconocida como prescriptora por la profesión.
The aim is to elaborate a model of integrated management system of documents and information for organizations with an approach focused on processes. To achieve this target the study analyses the scientific literature and a case study of three corporations. The conceptual and operational principles of the information system are exposed. The objectives, components and subsystems structure commons to an integrated system are indicated. The six stages of the design, planning and assessment method are described. It concludes that this proposal can serves as a basis for some guidelines to any organization by a standardizing institution or accepted as prescriber by the profession
Topography of Cortical Activation Differs for Fundamental and Harmonic Frequencies of the Steady-State Visual-Evoked Responses. An EEG and PET H15 2 O Study
In humans, visual flicker stimuli of graded frequency (2--90 Hz) elicit
an electroencephalographic (EEG) steady-state visual-evoked response
(SSVER) with the same fundamental frequency as the stimulus
and, in addition, a series of harmonic responses. The fundamental
component of the SSVER is generated by increased synaptic activity
in primary visual cortex (V1). We set out to determine the cortical
origin of the harmonic responses in humans. For this purpose, we
recorded the SSVERs at 5 different frequencies (5, 10, 15, 25, and 40
Hz) and measured regional cerebral blood flow (rCBF) with positron
emission tomography-H15
2 O at rest and during visual stimulation at
the same frequencies. The rCBF contrast weighted by the amplitude
of the SSVERs first harmonics showed activation of a swath of cortex
perpendicular to V1, including mostly the inferior half of the parietooccipital
sulcus. This area overlapped minimally with the primary
visual cortex activated by the fundamental frequency. A different
method, estimating EEG cortical source current density with lowresolution
brain electromagnetic tomography, gave the same results.
Our finding suggests that the inferior portion of the banks of the
parieto-occipital sulci contains association visual cortex involved in
the procparieto-occipital sulcus
Molecular identification and characterization of haptoglobin in teleosts revealed an important role on fish viral infections
Haptoglobin (Hp) molecule has been cloned and characterized in two marine teleosts (gilthead seabream and European sea bass), obtaining putative proteins of 319 residues encoded by an ORF of 960 bp in both species. However, the matrix of similarity revealed low identities among bony fish species 78.9% (seabream-sea bass), 43% (seabream/seabass-zebrafish) and lower than 20% with sharks and human. The protein sequences showed a signal peptide from the position 1 to 23, a trypsin domain from 47 to 297, and several predicted disulfide bridges and glycosylation sites. The expression of hp transcript levels during ontogeny showed a progressive increase of expression in seabream whilst remained almost unaltered in sea bass. By tissues, this gene was found constitutively expressed with the highest levels on liver in both species. The main results on hp transcript levels showed the up-regulation in gilthead seabream suffering from naturally occurring lymphocystis disease; and the down-regulation and up-regulation after nodavirus infection in the resistant gilthead seabream and the susceptible European sea bass, respectively. These findings demonstrate for the first time an important role of haptoglobin against viral infections, operating differently in two of the most important marine farmed fish species.Postprint3,26
Fish granzymes and their role in the innate cell-mediated cytotoxicity against nodavirus-infected cells
Granzymes (Gzm) are granule-associated serine proteases, which are important effector molecules in cell-mediated cytotoxicity, classified by its proteolytic activity in: tryptase (GzmA and GzmK), Asp-ase (GzmB), Met-ase (GzmM) or chymase (others). In fish, even at gene level, very few studies have partially identified and characterize them. In this work we have identified the activity of these four granzymes, using colorimetric assays, in leucocytes from gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax), and how they are increased upon cytotoxic activity against nodavirus-infected tumor cells. The results also showed that GzmA was the most abundant and GzmB the lowest. Deeper characterization of the GzmB led us to identify that seabream leucocytes under cytotoxic response against nodavirus-infected cells showed significantly increased GzmB activity whilst this pattern failed to do so in sea bass leucocytes. Moreover, flow cytometry studies also suggested the presence of GzmB into the cytoplasm of effector cells. At gene level, seabream GzmB gene was found to be up-regulated in leucocytes under cytotoxic activity, mainly if the target cells were infected with nodavirus. These data will through some light in the importance of granzymes in the cytotoxic response of fish and their defense against nodavirus infection
Implications of granzyme B in the immune response of gilthead seabream against nodavirus (NNV)
Transcription of histones H1 and H2B is regulated by several immune stimuli in gilthead seabream and European sea bass
Histones (H1 to H4) are the primary proteins which mediate the folding of DNA into chromatin; however, and in addition to this function, histones have been also related to antimicrobial peptides (AMPs) activity in vertebrates, in fact, mammalian H1 is mobilized as part as the anti-viral immune response. In fish, histones with AMP activity have been isolated and characterized mainly from skin and gonads. One of most threatening pathogens for wild and cultured fish species nowadays is nodavirus (NNV), which target tissues are the brain and retina, but it is also able to colonize the gonad and display vertical transmission. Taking all this into account we have identified the h1 and h2b coding sequences in Eu- ropean sea bass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) fish species and studied their pattern of expression under naïve conditions and NNV in vivo infection. The data obtained prompted us to study their role on the immune response of gonad and head-kidney leucocytes upon viral (NNV), bacteria (Vibrio anguillarumor Photobacteriumdamselae), pathogen-associated molecular patterns (PAMPs) or mitogens stimulation. The h1 and h2b genes are expressed in a wide range of tissues and their expression is modify by infection or other immune stimuli, but further studies will be needed to determine the significance of these changes. These results suggest that h1 expression is related to the immune response against NNV in the brain, while h2b transcription seems to be more important in the head-kidney. Moreover, the potential role of histones as anti-viral agents is suggested and further characterization is in progress
The treatment with the probiotic Shewanella putrefaciens Pdp11 of sepecimens of Solea senegalensis exposed to high stocking densities to enhance their resistance to disease
Aquaculture industry exposes fish to acute stress events, such as high stocking density, and a link between
stress and higher susceptibility to diseases has been concluded. Several studies have demonstrated
increased stress tolerance of fish treated with probiotics, but the mechanisms involved have not
been elucidated. Shewanella putrefaciens Pdp11 is a strain isolated from healthy gilthead seabream
(Sparus aurata L.) and it is considered as probiotics. The aim of this study was to evaluate the effect of the
dietary administration of this probiotics on the stress tolerance of Solea senegalensis specimens farmed
under high stocking density (PHD) compared to a group fed a commercial diet and farmed under the
same conditions (CHD). In addition, during the experiment, a natural infectious outbreak due to Vibrio
species affected fish farmed under crowding conditions. Changes in the microbiota and histology of
intestine and in the transcription of immune response genes were evaluated at 19 and 30 days of the
experiment. Mortality was observed after 9 days of the beginning of the experiment in CHD and PHD
groups, it being higher in the CHD group. Fish farmed under crowding stress showed reduced expression
of genes at 19 day probiotic feeding. On the contrary, a significant increase in immune related gene
expression was detected in CHD fish at 30 day, whereas the gene expression in fish from PHD group was
very similar to that showed in specimens fed and farmed with the conventional conditions. In addition,
the dietary administration of S. putrefaciens Pdp11 produced an important modulation of the intestinal
microbiota, which was significantly correlated with the high number of goblet cells detected in fish fed
the probiotic diet.Postprin
Inactivated nervous necrosis virus (NNV) vaccine elicits antiviral activity and protection in the teleost European sea bass (Dicentrarchus labrax)
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