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Search Results: 1 - 10 of 1812 matches for " Gabriele Procaccini "
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Copepod Population-Specific Response to a Toxic Diatom Diet
Chiara Lauritano, Ylenia Carotenuto, Antonio Miralto, Gabriele Procaccini, Adrianna Ianora
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0047262
Abstract: Diatoms are key phytoplankton organisms and one of the main primary producers in aquatic ecosystems. However, many diatom species produce a series of secondary metabolites, collectively termed oxylipins, that disrupt development in the offspring of grazers, such as copepods, that feed on these unicellular algae. We hypothesized that different populations of copepods may deal differently with the same oxylipin-producing diatom diet. Here we provide comparative studies of expression level analyses of selected genes of interest for three Calanus helgolandicus populations (North Sea, Atlantic Ocean and Mediterranean Sea) exposed to the same strain of the oxylipin-producing diatom Skeletonema marinoi using as control algae the flagellate Rhodomonas baltica. Expression levels of detoxification enzymes and stress proteins (e.g. glutathione S-transferase, glutathione synthase, superoxide dismutase, catalase, aldehyde dehydrogenases and heat shock proteins) and proteins involved in apoptosis regulation and cell cycle progression were analyzed in copepods after both 24 and 48 hours of feeding on the diatom or on a control diet. Strong differences occurred among copepod populations, with the Mediterranean population of C. helgolandicus being more susceptible to the toxic diet compared to the others. This study opens new perspectives for understanding copepod population-specific responses to diatom toxins and may help in underpinning the cellular mechanisms underlying copepod toxicity during diatom blooms.
An integration of historical records and genetic data to the assessment of global distribution and population structure in Octopus vulgaris
Daniele De Luca,Gaetano Catanese,Gabriele Procaccini,Graziano Fiorito
Frontiers in Ecology and Evolution , 2014, DOI: 10.3389/fevo.2014.00055
Abstract: The common octopus (Octopus vulgaris Cuvier, 1797) is one of the most widely distributed species belonging to the genus Octopus as well as an important commercially harvested species and a model organism for behavioral biology of invertebrates. It has been described for the first time in the Mediterranean Sea but it is considered a cosmopolitan species inhabiting the temperate and tropical seas of the northern and southern hemispheres. In the last few years, several species previously considered as O. vulgaris have been recognized as new species, limiting the distributional range of “vulgaris” and reinforcing the thesis of a species complex. Where it is an important fishery resource, numerous studies have been conducted in order to define its genetic structure with the purpose of managing different stocks. However, many locations are still poorly investigated from this point of view and others are under taxonomic revision to exclude or confirm its occurrence. Here we provide a summary of the current status of knowledge on distribution and genetic structure in this species in the different oceanic regions.
Molecular Evidence of the Toxic Effects of Diatom Diets on Gene Expression Patterns in Copepods
Chiara Lauritano, Marco Borra, Ylenia Carotenuto, Elio Biffali, Antonio Miralto, Gabriele Procaccini, Adrianna Ianora
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0026850
Abstract: Background Diatoms are dominant photosynthetic organisms in the world's oceans and are considered essential in the transfer of energy through marine food chains. However, these unicellular plants at times produce secondary metabolites such as polyunsaturated aldehydes and other products deriving from the oxidation of fatty acids that are collectively termed oxylipins. These cytotoxic compounds are responsible for growth inhibition and teratogenic activity, potentially sabotaging future generations of grazers by inducing poor recruitment in marine organisms such as crustacean copepods. Principal Findings Here we show that two days of feeding on a strong oxylipin-producing diatom (Skeletonema marinoi) is sufficient to inhibit a series of genes involved in aldehyde detoxification, apoptosis, cytoskeleton structure and stress response in the copepod Calanus helgolandicus. Of the 18 transcripts analyzed by RT-qPCR at least 50% were strongly down-regulated (aldehyde dehydrogenase 9, 8 and 6, cellular apoptosis susceptibility and inhibitor of apoptosis IAP proteins, heat shock protein 40, alpha- and beta-tubulins) compared to animals fed on a weak oxylipin-producing diet (Chaetoceros socialis) which showed no changes in gene expression profiles. Conclusions Our results provide molecular evidence of the toxic effects of strong oxylipin-producing diatoms on grazers, showing that primary defense systems that should be activated to protect copepods against toxic algae can be inhibited. On the other hand other classical detoxification genes (glutathione S-transferase, superoxide dismutase, catalase, cytochrome P450) were not affected possibly due to short exposure times. Given the importance of diatom blooms in nutrient-rich aquatic environments these results offer a plausible explanation for the inefficient use of a potentially valuable food resource, the spring diatom bloom, by some copepod species.
Back to the sea twice: identifying candidate plant genes for molecular evolution to marine life
Lothar Wissler, Francisco M Codo?er, Jenny Gu, Thorsten BH Reusch, Jeanine L Olsen, Gabriele Procaccini, Erich Bornberg-Bauer
BMC Evolutionary Biology , 2011, DOI: 10.1186/1471-2148-11-8
Abstract: In our study, we provide the first quantitative perspective on molecular adaptations in two seagrass species. By constructing orthologous gene clusters shared between two seagrasses (Z. marina and P. oceanica) and eight distantly related terrestrial angiosperm species, 51 genes could be identified with detection of positive selection along the seagrass branches of the phylogenetic tree. Characterization of these positively selected genes using KEGG pathways and the Gene Ontology uncovered that these genes are mostly involved in translation, metabolism, and photosynthesis.These results provide first insights into which seagrass genes have diverged from their terrestrial counterparts via an initial aquatic stage characteristic of the order and to the derived fully-marine stage characteristic of seagrasses. We discuss how adaptive changes in these processes may have contributed to the evolution towards an aquatic and marine existence.Lambers and co-authors summarized the uniqueness of seagrasses as follows: "Aquatic angiosperms are perhaps comparable to whales: They returned to the water, preserving some features of terrestrial organisms" [1]. The monocotyledonous seagrasses represent, in fact, a polyphyletic group of plants that can live underwater in fully marine environments. At least three independent seagrass lineages, but no other angiosperm species, have evolved to a life in the marine environment [2,3].Seagrasses consist of about 60 species, most of which superficially resemble terrestrial grasses of the family Poaceae in that they have long, narrow leaves and grow in large meadows. Seagrasses belong to the order of Alismatales which includes 11 families of aquatic-freshwater species and 4 families that are fully marine. The marine families include the Posidoniaceae, Zosteraceae, Hydrocharitaceae, and Cymodoceaceae, and have originated in the Cretaceous period [2]. Phylogenetic analysis of members of the entire order, based on the plastid gene encoding for RuBi
A Sieve for Prime Based on Extension Form of Not Prime  [PDF]
Gabriele Martino
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.31014
Abstract:

This paper will illustrate two versions of an algorithm for finding prime number up to N, which give the first version complexity

\"\" (1)

where c1, c2 are constants, and N is the input dimension, and gives a better result for the second version. The method is based on an equation that expresses the behavior of not prime numbers. With this equation it is possible to construct a fast iteration to verify if the not prime number is generated by a prime and with which parameters. The second method differs because it does not pass other times over a number that has been previously evaluated as not prime. This is possible for a recurrence of not prime number that is (mod 3) = 0. The complexity in this case is better than the first. The comparison is made most with Mathematics than by computer calculation as the number N should be very big to appreciate the difference between the two versions. Anyway the second version results better. The algorithms have been

Primality Test  [PDF]
Gabriele Martino
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.31009
Abstract:

In this paper we will give an algorithm that in the worst case solve the question about the primality of a number in \"\" but that gives better result if the number is not prime (constant operation). Firstly, we will introduce an equation on which are based not prime numbers. With this equation it is possible to deduce the prime number that generates a not prime number and to establish an equation in which if exists a certain integer the number is not prime and therefore vice versa to deduce if it is prime.

Solving a Traveling Salesman Problem with a Flower Structure  [PDF]
Gabriele Martino
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.27079
Abstract:

This works aims to give an answer to the problem P = NP? The result is positive with the criteria that solve the Traveling Salesman Problem in polynomial cost of the input size and a proof is given. This problem gets a solution because a polyhedron, with a cut flower looking, is introduced instead of graph (e.g. tree).

On the Fractal Design in Human Brain and Nervous Tissue  [PDF]
Gabriele A. Losa
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.512165
Abstract:


Digital imaging techniques have enabled to gain insight into complex structure-functional processes involved in the neo-cortex maturation and in brain development, already recognized in anatomical and histological preparations. Despite such a refined technical progress most diagnostic records sound still elusive and unreliable because of use of conventional morphometric approaches based on a unique scale of measure, inadequate for investigating irregular cellular components and structures which shape nervous and brain tissues. Instead, these could be efficiently analyzed by adopting principles and methodologies derived from the Fractal Geometry. Through his masterpiece, The Fractal Geometry of Nature [1], Benoît Mandelbrot has provided a novel epistemological framework for interpreting the real life and the natural world as they are, preventing whatever approximation or subjective sight. Founded upon a body of well-defined laws and coherent principles, the Fractal Geometry is a powerful tool for recognizing and quantitatively describing a good many kinds of complex shapes, living forms, organized patterns, and morphologic features long range correlated with a broad network of functional interactions and metabolic processes that contribute to building up adaptive responses making life sustainable. Scale free dynamics characterized biological systems which develop through the iteration of single generators on different scales thus preserving proper self-similar traits. In the last decades several studies have contributed to showing how relevant may be the recognition of fractal properties for a better understanding of brain and nervous tissues either in healthy conditions or in altered and pathological states.


Applications of Fractional Calculus to Newtonian Mechanics  [PDF]
Gabriele U. Varieschi
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.66105
Abstract: We investigate some basic applications of Fractional Calculus (FC) to Newtonian mechanics. After a brief review of FC, we consider a possible generalization of Newton’s second law of motion and apply it to the case of a body subject to a constant force. In our second application of FC to Newtonian gravity, we consider a generalized fractional gravitational potential and derive the related circular orbital velocities. This analysis might be used as a tool to model galactic rotation curves, in view of the dark matter problem. Both applications have a pedagogical value in connecting fractional calculus to standard mechanics and can be used as a starting point for a more advanced treatment of fractional mechanics.
Dissecting the Specificity of Protein-Protein Interaction in Bacterial Two-Component Signaling: Orphans and Crosstalks
Andrea Procaccini,Bryan Lunt,Hendrik Szurmant,Terence Hwa,Martin Weigt
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0019729
Abstract: Predictive understanding of the myriads of signal transduction pathways in a cell is an outstanding challenge of systems biology. Such pathways are primarily mediated by specific but transient protein-protein interactions, which are difficult to study experimentally. In this study, we dissect the specificity of protein-protein interactions governing two-component signaling (TCS) systems ubiquitously used in bacteria. Exploiting the large number of sequenced bacterial genomes and an operon structure which packages many pairs of interacting TCS proteins together, we developed a computational approach to extract a molecular interaction code capturing the preferences of a small but critical number of directly interacting residue pairs. This code is found to reflect physical interaction mechanisms, with the strongest signal coming from charged amino acids. It is used to predict the specificity of TCS interaction: Our results compare favorably to most available experimental results, including the prediction of 7 (out of 8 known) interaction partners of orphan signaling proteins in Caulobacter crescentus. Surveying among the available bacterial genomes, our results suggest 15~25% of the TCS proteins could participate in out-of-operon “crosstalks”. Additionally, we predict clusters of crosstalking candidates, expanding from the anecdotally known examples in model organisms. The tools and results presented here can be used to guide experimental studies towards a system-level understanding of two-component signaling.
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