54 research outputs found

    New Mediterranean Biodiversity Records (April 2015)

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    The Collective Article ‘New Mediterranean Biodiversity Records’ of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided in two parts, for records of native and alien species respectively. The new records of native fish species include: the slender sunfish Ranzania laevis and the scalloped ribbonfish Zu cristatus in Calabria; the Azores rockling Gaidropsarus granti in Calabria and Sicily; the agujon needlefish Tylosu¬rus acus imperialis in the Northern Aegean; and the amphibious behaviour of Gouania willdenowi in Southern Turkey. As regards molluscs, the interesting findings include Ischnochiton usticensis in Calabria and Thordisa filix in the bay of Piran (Slovenia). The stomatopod Parasquilla ferussaci was collected from Lesvos island (Greece); the isopod Anilocra frontalis was observed parasit¬izing the alien Pteragogus trispilus in the Rhodes area. The asteroid Tethyaster subinermis and the butterfly ray Gymnura altavela were reported from several localities in the Greek Ionian and Aegean Seas.The new records of alien species include: the antenna codlet Bregmaceros atlanticus in Saronikos Gulf; three new fish records and two decapods from Egypt; the establishment of the two spot cardinal fish Cheilodipterus novemstriatus and the first record of the marble shrimp Saron marmoratus in semi-dark caves along the Lebanese coastline; the finding of Lagocephalus sceleratus, Sargocentron rubrum, Fistularia commersonii and Stephanolepis diaspros around Lipsi island (Aegean Sea, Greece); the decapod Penaeus Hathor in Aegean waters; the decapod Penaeus aztecus and the nudibranch Melibe viridis in the Dodecanese islands; the finding of Pinctada imbricata radiate in the Mar Grande of Taranto (Ionian Sea, Italy) and the Maliakos Gulf (Greece)

    Calculation of the relative metastabilities of proteins in subcellular compartments of Saccharomyces cerevisiae

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    [abridged] Background: The distribution of chemical species in an open system at metastable equilibrium can be expressed as a function of environmental variables which can include temperature, oxidation-reduction potential and others. Calculations of metastable equilibrium for various model systems were used to characterize chemical transformations among proteins and groups of proteins found in different compartments of yeast cells. Results: With increasing oxygen fugacity, the relative metastability fields of model proteins for major subcellular compartments go as mitochondrion, endoplasmic reticulum, cytoplasm, nucleus. In a metastable equilibrium setting at relatively high oxygen fugacity, proteins making up actin are predominant, but those constituting the microtubule occur with a low chemical activity. A reaction sequence involving the microtubule and spindle pole proteins was predicted by combining the known intercompartmental interactions with a hypothetical program of oxygen fugacity changes in the local environment. In further calculations, the most-abundant proteins within compartments generally occur in relative abundances that only weakly correspond to a metastable equilibrium distribution. However, physiological populations of proteins that form complexes often show an overall positive or negative correlation with the relative abundances of proteins in metastable assemblages. Conclusions: This study explored the outlines of a thermodynamic description of chemical transformations among interacting proteins in yeast cells. The results suggest that these methods can be used to measure the degree of departure of a natural biochemical process or population from a local minimum in Gibbs energy.Comment: 32 pages, 7 figures; supporting information is available at http://www.chnosz.net/yeas

    Effect of Virulence Factors on the Photodynamic Inactivation of Cryptococcus neoformans

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    Opportunistic fungal pathogens may cause an array of superficial infections or serious invasive infections, especially in immunocompromised patients. Cryptococcus neoformans is a pathogen causing cryptococcosis in HIV/AIDS patients, but treatment is limited due to the relative lack of potent antifungal agents. Photodynamic inactivation (PDI) uses the combination of non-toxic dyes called photosensitizers and harmless visible light, which produces singlet oxygen and other reactive oxygen species that produce cell inactivation and death. We report the use of five structurally unrelated photosensitizers (methylene blue, Rose Bengal, selenium derivative of a Nile blue dye, a cationic fullerene and a conjugate between poly-L-lysine and chlorin(e6)) combined with appropriate wavelengths of light to inactivate C. neoformans. Mutants lacking capsule and laccase, and culture conditions that favoured melanin production were used to probe the mechanisms of PDI and the effect of virulence factors. The presence of cell wall, laccase and melanin tended to protect against PDI, but the choice of the appropriate photosensitizers and dosimetry was able to overcome this resistance.Fundação de Amparo à Pesquisa do Estado de São Paulo (2010/13313–9

    Degradation attacks on Passive Optical Networks

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    Passive Optical Networks (PONs) are a promising candidate to solve the last-mile problem in access networks. By using optical fibers, PONs can offer to the subscribers higher capacity than other traditional access technologies, such as xDSL or Cable-TV, at a lower cost than FTTx solutions. As for any other access-network technology, security is a very important issue. PONs have very specific security requirements because (i) the downstream transmission channel is inherently broadcast, and (ii) malicious transmissions in the upstream channel can not be easily detected and prevented. This paper shows that malicious upstream transmissions can be used to conduct very intrusive degradation attacks upon the upstream traffic and quantifies the decrement of the upstream throughput over a PON under different scenarios of degradation attack. Further, the paper considers how the effect of a degradation attack carried on at the physical layer is greatly amplified by the TCP congestion control algorithm resulting in a strong degradation with little effort by the attacker. The attacker could then exploit bandwidth sharing mechanisms to gain an unfair amount of bandwidth. We also propose a possible mitigation strategy that pinpoints the attacker and re-establishes fairness in terms of throughput per ONU

    Competition Law in Kosovo: Problems and Challenges

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    Competition Law is an important aspect of free market economy. It determines the functioning of the economic system based on the free market principles of supply and demand. Competition law is in the initial stage of its implementation in the Republic of Kosovo. Its development began in 2004 with the adoption of Kosovo’s Law on Competition, the country’s very first law passed to regulate the legal basis of free market competition. The Law on Competition of 2004 had many shortcomings both with respect to its content and implementation. New legislation was thus passed in 2010 under the name the Law on the Protection of Competition. The latter act is in force now along with an Amendment that entered into force in early 2014. Taken in its entirety, Kosovo’s competition law meets the standards and is in accordance with EU legislation. Kosovo, although it is only in the initial stage of its contractual relations with the EU, has aligned most of its laws with the requirements of EU legislation. Kosovo is Europe’s youngest country and as such, it has various problems when it comes to the functioning of the rule of law. This paper will discuss several topics related to the development of competition law in Kosovo including: the political, legal and economical situation in the field of competition law; the legal bases for the protection of competition in Kosovo; the Kosovo Competition Authority and the insufficiency in its capacities to combat competition law infringements; legal provisions on restrictive practices and merger control. The paper also includes comprehensive conclusions. A number of competition cases deal with by the Kosovo Competition Authority will be mentioned throughout the paper

    Substitued (E)-b-(benzoyl)acrylic acids suppressed survival of neoplastic human HeLa cells

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    The bacteriostatic activity of some of alkyl substituted (E)-b-(benzoyl)acrylic acids was shown earlier. The aim of this study was to investigate the antiproliferative action of 19 alkyl-, or halogeno-, or methoxy-, or acetamido- substituted (E)-b-(benzoyl)acrylic acids, against human cervix carcinoma, HeLa, cells. Target HeLa cells were continuously treated with increasing concentrations of substituted (E)-b-(benzoyl)acrylic acids during two days. The MTT test was used for assessment of the antiproliferative action of this group of compounds. Treatment of HeLa cells with 4-methyl-, 4-fluoro-, 4-chloro-, 4-bromo- and 4-methoxy- derivatives of (E)-b-(benzoyl) acrylic acid leads to the expression of cytostatic activity against HeLa cells (IC50 were in the range from 31-40 µM). Their antiproliferative action was less than that of the basic compound (E)-b-(benzoyl)acrylic acid whose IC50 was 28.5 µM. The 3,4-dimethyl-, 2,4-dimethyl- and 2,5-dimethyl- derivatives as well as the 4-ethyl- and 3,4-dichloro- and 2,4-dichloro-derivatives, have stronger cytostatic activity than the correspoding monosubstituted and parent compound. Their IC50 were 18.5 µM; 17.5 µM; 17.0 mM; 17.5 µM; 22.0 µM and 18 µM, respectively. The 4-iso-propyl- and 4-n-butyl-derivatives exerted higher cytostatic activity than the compounds with a lower number of methylene -CH2- groups in the substitutent. Their IC50 were 14.5 µM and 6.5 µM respectively. The 2,5-di-iso-propyl- and 4-tert-butyl-derivatives expressed the most strong antiproliferative action against the investigated HeLa cells, IC50 being 4.5 µM and 5.5 µM, respectively. The investigated compounds affected the survival of HeLa cells, expressing a strong structure-activity relationship of the Hansch type

    Sharing a host plant (wheat [Triticum aestivum]) increases the fitness of Fusarium graminiearum and the severity of fusarium head blight but reduces the fitness of grain aphids (Sitobion avenae)

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    We hypothesized that interactions between fusarium head blight-causing pathogens and herbivores are likely to occur because they share wheat as a host plant. Our aim was to investigate the interactions between the grain aphid, Sitobion avenae, and Fusarium graminearum on wheat ears and the role that host volatile chemicals play in mediating interactions. Wheat ears were treated with aphids and F. graminearum inoculum, together or separately, and disease progress was monitored by visual assessment and by quantification of pathogen DNA and mycotoxins. Plants exposed to both aphids and F. graminearum inoculum showed accelerated disease progression, with a 2-fold increase in disease severity and 5-fold increase in mycotoxin accumulation over those of plants treated only with F. graminearum. Furthermore, the longer the period of aphid colonization of the host prior to inoculation with F. graminearum, the greater the amount of pathogen DNA that accumulated. Headspace samples of plant volatiles were collected for use in aphid olfactometer assays and were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-coupled electroantennography. Disease-induced plant volatiles were repellent to aphids, and 2-pentadecanone was the key semiochemical underpinning the repellent effect. We measured aphid survival and fecundity on infected wheat ears and found that both were markedly reduced on infected ears. Thus, interactions between F. graminearum and grain aphids on wheat ears benefit the pathogen at the expense of the pest. Our findings have important consequences for disease epidemiology, because we show increased spread and development of host disease, together with greater disease severity and greater accumulation of pathogen DNA and mycotoxin, when aphids are present
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