817 research outputs found

    Nove vrste - marikultura na istočnom Jadranu

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    As production of seabass and sea bream has expanded in the Mediterranean over the past decade, prices for each have fallen dramatically. The lower revenues that have resulted have forced some once-profitable producers out of business and made entry into the market by new producers much more difficult. This reality must be taken into account in formulating any successful national or enterprise-level development plan based on production of these “old” species. Introduction of “new” commercial species is one possible response, and several fish and invertebrates have received attention in this regard. Of the invertebrates, one echinoderm, the sea urchin Paracentrotus lividus, and two molluscs, the cuttlefish Sepia officinalis and the common octopus Octopus vulgaris, appear to have sufficient potential for Croatian mariculture to warrant closer examination of their advantages and disadvantages, and to invest the capital and effort on applied research to overcome the latter. In the case of the cephalopods, full commercialization of both cuttlefish and octopus is limited by availability of an economical crustacean feed for early stages. Further, although culture systems for cuttlefish are well established, a octopus grow-out system that satisfactorily reduces the animal’s natural agonistic tendencies while permitting unencumbered routine feeding and maintenance has yet to be identified. Commercial sea urchin cultivation is limited by several factors, including an efficient juvenile feed; but the quickest route to sea urchin commercialization is out-of-season gonad (roe) enhancement of natural stock, analogous to the way in which the successful Croatian tuna-ranching industry operates. The success of this ‘bulking’ process depends upon availability of an effective diet and a containment system that addresses the peculiarities of sea urchin behavior in captivity. Of the three species examined briefly here, cuttlefish can be commercialized the fastest. The next step in cuttlefish development is to operate pilot-scale production trials to evaluate its economic feasibility under Croatian conditions. ‘Bulking’ of sea urchin offers the next most promising new commercial opportunity and merits feed trials using at least one of several published feed formulations, perhaps followed by a diet of local macroalgae to ‘polish’ the product’s taste to market standards. Octopus now appears to be the least ready of the three. A positive step in its development in Croatia is to transfer the latest techniques on paralarval rearing, the better to be prepared to take full commercial advantage of further advances in this area as they become available.Radi povećane produkcije lubina i komarče na Mediteranu, u posljednjih deset godina njihova je cijena znatno pala. Smanjeni prihodi prisilili su mnoge proizvođače da napuste ovaj posao, a ulazak novih proizvođača na trĆŸiĆĄte postaje sve teĆŸi. Ova činjenica mora se uzeti u obzir pri izradi razvojnog plana koji se zasniva na produkciji starih vrsta u uzgoju, bilo to na nacionalnoj razini ili na razini poduzetniĆĄtva. Mogući odgovor na ovu problematiku je unos novih vrsta u uzgoj. Neke ribe i beskraljeĆŸnjaci već neko vrijeme privlače pozornost kao novi kandidati za akvakulturu. U skupini beskraljeĆŸnjaka pojavljuju se tri potencijalne vrste za uzgoj: morski jeĆŸinac, Paracentrotus lividus iz razreda Echinoidea, i dva pripadnika reda mekuĆĄaca, sipa Sepia officinalis i hobotnica Octopus vulgaris. Ove tri vrste imaju dovoljan potencijal da bi se omogućio detaljniji pregled prednosti i nedostataka njihova uzgoja, te investirao novac u primijenjena istraĆŸivanja kako bi se svladali nedostaci. Kod glavonoĆŸaca je limitirajući faktor komercijalne proizvodnje raspoloĆŸivost račića kojima se koristi kao hranom u ranim razvojnim fazama sipe i hobotnice. Iako je uzgojni sustav za sipu već poznat, za hobotnicu, onaj kojim bi se uspjeĆĄno reducirale njezine antagonističke tendencije i ujedno osigurala nesmetana hranidba i odrĆŸavanje, joĆĄ uvijek nije poznat. Pri komercijalnom uzgoju jeĆŸinaca prepoznato je nekoliko limitirajućih čimbenika, među kojima je nedovoljna količina hrane za mlađ. NajbrĆŸi put do komercijalizacije je izvansezonsko obogaćivanje gonada (ikre) prirodnih populacija, slično uspjeĆĄnom načinu uzgoja tuna u Hrvatskoj. Uspjeh metode tovljenja ovisi o raspoloĆŸivosti hrane i adekvatnoga uzgojnog sustava kojima se uzimaju u obzir behaviorističke karakteristike jeĆŸinca u zatočeniĆĄtvu. Od tri proučavane vrste, sipa ima najbrĆŸu mogućnost komercijalizacije. Da bi se procijenio potencijal njezina uzgoja, u Hrvatskoj je potrebno napraviti eksperimentalni dizajn proizvodnje. Sljedeća tehnologija obećavajuća za komercijalizaciju marikulture u Hrvatskoj jest kondicioniranje gonada jeĆŸinca, pri čemu valja ispitati uporabivost nekih od postojećih hranjiva, uz mogući dodatak lokalnih alga kako bi se usavrĆĄio okus proizvoda i zadovoljile trĆŸiĆĄne potrebe. Od tri spomenute vrste, hobotnica je najmanje pogodna za komercijalizaciju. U Hrvatskoj se trenutno mogu primijeniti dosadaĆĄnja znanja i tehnologije na ličinačkom uzgoju ove vrste kako bi bila spremna za daljnju komercijalizaciju, ali tek uz nove znanstvene spoznaje

    Future challenges in cephalopod research

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    We thank Anto®nio M. de Frias Martins, past President of the Unitas Malacologica and Peter Marko, President of the American Malacological Society for organizing the 2013 World Congress of Malacology, and the Cephalopod International Advisory Committee for endorsing a symposium held in honour of Malcolm R. Clarke. In particular, we would like to thank the many professional staff from the University of the Azores for their hospitality, organization, troubleshooting and warm welcome to the Azores. We also thank Malcolm Clarke’s widow, Dorothy, his daughter Zoe¹, Jose® N. Gomes-Pereira and numerous colleagues and friends of Malcolm’s from around the world for joining us at Ponta Delgada. We are grateful to Lyndsey Claro (Princeton University Press) for granting copyright permissions.Peer reviewedPublisher PD

    Editorial: Cephalopods in the Anthropocene: multiple challenges in a changing ocean

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    Editorial on the Research Topic Cephalopods in the Anthropocene: multiple challenges in a changing ocean.-- 4 pages, 1 figureThe Anthropocene describes the new geological epoch driven by humankind (Lewis and Maslin, 2015). Overfishing, pollution, and climate change are some of the unquestionable human-driven threats to ocean biodiversity (Pauly et al., 1998; Poloczanska et al., 2013; Steneck and Pauly, 2019; Sampaio et al., 2021) and within the notion of winners and losers of global change, there is evidence that some cephalopod populations may be benefiting from this changing ocean (Doubleday et al., 2016; Oesterwind et al., 2022). Within this context, this Research Topic (RT) aimed to compile the latest advances in cephalopod research, covering a wide range of disciplines, and encompassing different levels of biological organization (from molecules to ecosystems). Authors who contributed to the triennial Cephalopod International Advisory Council (CIAC) Meeting held in Sesimbra (Portugal), in April 2022, were especially encouraged to submit their findings here. CIAC 2022 provided a forum to discuss global issues related to human impacts while presenting the latest advances in cephalopod research. The meeting encompassed 90 oral presentations and 145 posters, grouped into eight topic sessions (Figure 1A), with 166 participants in person and 109 participants online, from 33 countries (Figure 1B)With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

    The significance of cephalopod beaks as a research tool: An update

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    The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960's, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed.info:eu-repo/semantics/publishedVersio

    Evidence for Transcript Networks Composed of Chimeric RNAs in Human Cells

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    The classic organization of a gene structure has followed the Jacob and Monod bacterial gene model proposed more than 50 years ago. Since then, empirical determinations of the complexity of the transcriptomes found in yeast to human has blurred the definition and physical boundaries of genes. Using multiple analysis approaches we have characterized individual gene boundaries mapping on human chromosomes 21 and 22. Analyses of the locations of the 5â€Č and 3â€Č transcriptional termini of 492 protein coding genes revealed that for 85% of these genes the boundaries extend beyond the current annotated termini, most often connecting with exons of transcripts from other well annotated genes. The biological and evolutionary importance of these chimeric transcripts is underscored by (1) the non-random interconnections of genes involved, (2) the greater phylogenetic depth of the genes involved in many chimeric interactions, (3) the coordination of the expression of connected genes and (4) the close in vivo and three dimensional proximity of the genomic regions being transcribed and contributing to parts of the chimeric RNAs. The non-random nature of the connection of the genes involved suggest that chimeric transcripts should not be studied in isolation, but together, as an RNA network

    The SPARC Toroidal Field Model Coil Program

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    The significance of cephalopod beaks as a research tool: An update

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    The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960’s, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed

    Measurement of differential cross sections for top quark pair production using the lepton plus jets final state in proton-proton collisions at 13 TeV

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    National Science Foundation (U.S.

    Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV

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    Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated tt‟\mathrm{t}\overline{\mathrm{t}} events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The heavy-flavour jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV)
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