453 research outputs found
Tõrkeid taluv võrk, mis baseerub Linux süsteemil ja kasutab vana riistvara
Networking at enterprise level is fast, reliable,fault-tolerant, expensive
and usually includes a vendor lock-in. This thesis tries to take the good qualities
of the enterprise level networking and remove the negative side effects. One possible
way to solve the problem is to create a networking solution that uses obsolete
hardware and free software to neglect the negative properties of enterprise networking.
This kind of solution can be achieved without any need for more system
administration knowledge or know-how.
Moreover, the thesis conducts an analysis of the previous work done by other
people on fault tolerance in networking and offers the author’s own solution implementation.
The main result of this thesis is a low-cost solution to Internet service
provider and router failover. The tests that were carried out show that it is possible
to create a network that, even in the case of ISP and/or router failure, can
continue functioning at full speed without significant delays and without disrupting
the presently occurring data transmission. The thesis’s work uses computer
hardware that has been announced old by its previous owners and software that
is open source and readily deployable with a little skill.
From a theoretical point of view it should be acknowledged that the author
understands that software routing is not as good as hardware routing, however
the overall idea was to offer a solution which could theoretically perform as similar
as possible to the hardware routing
Report and genetic identification of Amyloodinium ocellatum in a sea bass (Dicentrarchus labrax) broodstock in Portugal
In this paper we report a case of amyloodiniosis in a sea bass (Dicentrarchus labrax) broodstock in Portugal. Microscopic examination of gill filaments showed the presence of trophonts while histological observation revealed gills epithelial hyperplasia, hypertrophy and lamellar fusion of secondary lamellae. The amplification and sequencing of the small subunit ribosomal RNA gene allowed the identification of the parasite as Amyloodinium ocellatum. It was also possible to amplify a partial sequence of ribosomal RNA from a Colpodellid, a predator of protists.This work was supported by DIVERSIAQUA and SAUDE&AQUA projects
[MAR2020 16-02-01-FMP-0066 and Mar2020 02.05.01-FEAMP-0009, respectively].
Márcio Moreira has a PhD grant from FCT - Foundation for Science and Technology
(SFRH/BD/118601/2016). This study also received Portuguese national funds from
FCT - Foundation for Science and Technology through project UID/Multi/04326/2019.info:eu-repo/semantics/publishedVersio
Selenium inclusion decreases oxidative stress indicators and muscle injuries in sea bass larvae fed high-DHA microdiets
The objective of the present study was to determine the effect of Se inclusion in high-DHA and vitamin E microdiets (5 g DHA/100 g dry weight and 300 mg vitamin E/100 g dry weight; 5 g DHA/100 g dry weight and 300 mg vitamin E/100 g dry weight supplemented with Se) in comparison with a control diet (1 g DHA/100 g dry weight and 150 mg vitamin E/100 g dry weight) on sea bass larval growth, survival, biochemical composition, malonaldehyde (MDA) content, muscle morphology and antioxidant enzymes (AOE), insulin-like growth factors (IGF) and myosin expression. For a given DHA and vitamin E dietary content, Se inclusion favoured larval total length and specific growth rate, and reduced the incidence of muscular lesions, MDA contents and AOE gene expression. In contrast, IGF gene expression was elevated in the 5/300 larvae, suggesting an increased muscle mitogenesis that was corroborated by the increase in mRNA copies of myosin heavy chain. The results of the present study denoted the beneficial effect of Se not only in preventing oxidative stress, as a glutathione peroxidase cofactor, but probably due to other as yet unknown physiological functions
Evaluation and comparison of trace metals accumulation in different tissues of potential bioindicator organisms: Macrobenthic filter feeders Styela plicata, sabella spallanzanii and Mytilus galloprovincialis
Trace metal concentrations were measured in different tissues of Sabella spallanzanii, Styela plicata and Mytilus galloprovincialis collected in Termini Imerese harbor, located in Sicily (Italy), in order to evaluate the potential use of these species as bioindicators. The higher bioaccumulation factors (BAFs) were calculated in tube of Sabella spallanzanii, except for As which shows the higher BAF in branchial crown of the same specie. Regarding the other species analyzed, higher BAFs were found in the digestive gland of Mytilus galloprovincialis. An exception is represented by Pb that is significantly more concentrated in branchial basket and tunic of Styela plicata. The BAFs here calculated, show that all the species analyzed are able to accumulate a certain amount of metals as a consequence of filter feeding mechanisms, and thus assess the suitability of the species Styela plicata, Sabella spallanzanii and Mytilus galloprovincialis as indicators of water quality. Particularly, the tube of Sabella spallanzanii is an important compartment in metal retention and the more suitable for the evaluation of the contamination caused by trace elements. This article is protected by copyright. All rights reserved
The role of melano‐macrophage aggregates in the storage of mercury and other metals: An example from yelloweye rockfish (Sebastes ruberrimus)
Melano‐macrophage aggregates, collections of specialized cells of the innate immune system of fish, are considered a general biomarker for contaminant toxicity. To elucidate further the relationship between macrophage aggregates and metals exposure, yelloweye rockfish (Sebastes ruberrimus), a long‐lived species, were sampled from the east and west coasts of Prince of Wales Island, Alaska. Metals concentrations in livers (inorganic Hg, methyl mercury, Se, Ni, Cd, Cu, Zn) and spleens (inorganic Hg and methyl mercury) were determined, as well as their correlations with melano‐macrophage aggregate area. Sections of liver tissue were analyzed by laser ablation‐inductively coupled plasma–mass spectrometry to determine how metals were spatially distributed between hepatocytes and macrophage aggregates. The concentration of inorganic Hg in whole tissue was the best predictor of macrophage area in yelloweye livers and spleens. Macrophage aggregates had higher relative concentrations than most metals compared with the surrounding hepatocytes. However, not all metals were accumulated to the same degree, as evidenced by differences in the ratios of metals in macrophages compared with hepatocytes. Laser ablation data were corroborated with the results of X‐ray synchrotron fluorescence imaging of a yelloweye liver section. Hepatic macrophage aggregates in yelloweye rockfish may play an important role in the detoxification and storage of Hg and other metals. Environ Toxicol Chem 2015;34:1918–1925. © 2015 SETACPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112257/1/etc3009.pd
Blood dynamics of mercury and selenium in northern elephant seals during the lactation period
The effects of reproduction and maternal investment (i.e., milk transfer) on trace element levels remain poorly understood in marine mammals. We examined the blood dynamics of mercury (Hg) and selenium (Se) during lactation in the northern elephant seal (Mirounga angustirostris), a top predator from the North Pacific Ocean. Total Hg and Se levels were measured in whole blood and milk of 10 mother-pup pairs on days 5 and 22 of lactation. Both Hg and Se were transferred to offspring through the milk. Results suggested that the maternal transfer of Se was prominent during lactation, whereas the Hg transfer was larger during gestation. The lactation period affected Hg and Se levels in the blood of elephant seal mothers and pups. Physiological processes and their relationship to body condition should be considered carefully when interpreting trace element levels in the framework of biomonitoring.Peer reviewe
Scanning electron microscopy and X-ray spectroscopy applied to mycelial phase of sporothrix schenckii
A review of the ecology, palaeontology and distribution of atlantid heteropods (Caenogastropoda: Pterotracheoidea: Atlantidae)
Fewer than 1% of marine gastropod species live a holoplanktic life. Of these, the shelled heteropods of the family Atlantidae are among the most poorly understood. The atlantids potentially make up an important part of the ocean zooplankton, composing up to 69% of shelled holoplanktic gastropods in the Late Pleistocene to Recent fossil record. They are also likely to be at high risk from current and future global changes, including anthropogenic ocean acidification. However, due to their small size (<12 mm), difficulty of sampling and complicated morphology, we still lack key information about atlantid taxonomy and ecology. This makes it difficult to understand how important they are in the ocean foodweb and how they will be affected by environmental change. Although many studies have been carried out on the atlantids, these have generally been broad and unconnected. Here, we draw together this previous research, summarizing what is currently known about atlantid taxonomy, palaeontology, ecology and biogeography, and aiming to provide a foundation for future research on this group. The data indicate complex behaviours involving seasonal and vertical migration, and demonstrate extended geographical ranges, with implications for understanding the role of atlantids in the ocean foodweb and their sensitivity to environmental changes. This review highlights the urgent need for further taxonomic research on the atlantids, including molecular analysis, and for improved sampling techniques
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