Phoma Macdonaldi na semenu i njen značaj u etiologiji crne pegavosti suncokreta

Phoma macdonaldi Boerema, teleomorph Leptosphaeria lindquistii Frezzi, is a widespread pathogen of sunflower. The aim of this research was to identify the presence of fungus P. macdonaldi in seed of different sunflower hybrids, as well as the correlation between seed and field infection. Phoma black stem assessment was performed on three hybrids grown in six localities in Serbia. Untreated and processed seeds of these hybrids were used in the seed health test. Severity of the disease did not differ between localities. Average disease index for hybrids H7, H9 and H19 was 14.01%, 13.25% and 11.83% respectively, and it shows that there are no significant differences in hybrid susceptibility. The index of disease indicates tolerance of these hybrids to Phoma black stem. Seed analysis showed the presence of fungi from the following genera: Phoma, Alternaria, Botrytis, Sclerotinia, Penicillium and Aspergillus. Seed infection with Phoma (of the untreated seeds) per hybrid ranged from 1.2–3.5%. There is no significant correlation between stem and seed infection.Phoma macdonaldi Boerema; teleomorf Leptosphaeria lindquistii Frezzi jedan je od najraširenijih patogena suncokreta. Cilj ovog istraživanja bio je da se utvrdi prisustvo gljive P. macdonaldi na semenu različitih hibrida suncokreta kao i korelacija između infekcije stabla u polju i infekcije semena. Procena inteziteta bolesti izvršena je na tri hibrida koja su gajena na šest lokaliteta. Za određivanje zdravstvenog stanja korišćeno je netretirano i dorađeno seme hibrida ispitivanih u polju. Intenzitet napada bolesti nije se značajno razlikovao među lokalitetima. Prosečan indeks oboljenja za hibride H7, H9 i H19 bio je 14,01%, 13,25% i 11,83% što pokazuje da ne postoje značajne razlike u osetljivosti hibrida prema crnoj pegavosti. Takođe, dobijeni indeks ukazuje na tolerantnost ispitivanih hibrida prema ovom prouzrokovaču bolesti. Analizom zdravstvenog stanja semena suncokreta utvrđeno je prisustvo gljiva iz sledećih rodova: Phoma, Alternaria, Botrytis, Sclerotinia, Penicillium i Aspergillus. Zaraženost semena gljivom P. macdonaldi utvrđena je na dorađenom i netretiranom semenu i kretala se od 1,2–3,5%. Nije utvrđena statistički značajna korelacija između infekcije stabla i semena u poljskim uslovima. Ovo se može objasniti niskim stepenom napada patogena i prisustvom simptoma samo na stablu, a ne na glavici suncokreta

Tidal energy machines: A comparative life cycle assessment

Marine energy in the UK is currently undergoing a period of exponential growth in terms of development and implementation. The current installed tidal energy capacity of around 4MW is expected to rise to provide up to 20% of the UK’s electricity demand by 2050 [5]. With this in mind, there is a huge range of energy devices, all seemingly promoted by their developers as the best method of extracting power from the ocean. Embodied energy is an important aspect of any power producing device or process, and is used to describe the amount of energy required to begin and maintain the process of energy generation. Until a device or process has generated this amount of energy it cannot be said to be a net contributor of energy. This work used Life Cycle Assessment to study four tidal energy devices, representing a cross section of the existing designs, and compares their embodied energy and carbon dioxide emissions. In order to ensure a fair comparison, a hypothetical installation site is used, with conditions typical of those found at potential array installation sites in the UK. The designs studied include a multi-blade turbine, two three blade horizontal axis turbine machines, and an Archimedes’ screw device. These machines were chosen to represent a cross section of device, foundation, installation and operation designs. They have all been developed to prototype stage, meaning that actual manufacturing data is available. Embodied energy is considered over the entire lifetime of each device, beginning with extraction of raw materials. Energy use from fabrication, transport, installation, lifetime maintenance, end-of-life decommissioning and recycling are all calculated, and compared to the energy generation from each device at the test site. Finally, the embodied energy; CO2 intensity; and energy payback periods are compared to those of conventional power generating systems as well as other renewable energy sources. A range of data sources are used. Embodied energy of steel has been provided by the World Steel Association. Of the four devices studied, all were found to achieve CO2 and energy payback within the first 12 years of their lifetime, and exhibited CO2 intensity of between 18 and 35 gCO2/kWh. This compares favourably to many current energy sources, and is likely to fall as technology improves, array size increases and industry experience progresses

On the Gold Standard for Security of Universal Steganography

While symmetric-key steganography is quite well understood both in the information-theoretic and in the computational setting, many fundamental questions about its public-key counterpart resist persistent attempts to solve them. The computational model for public-key steganography was proposed by von Ahn and Hopper in EUROCRYPT 2004. At TCC 2005, Backes and Cachin gave the first universal public-key stegosystem - i.e. one that works on all channels - achieving security against replayable chosen-covertext attacks (SS-RCCA) and asked whether security against non-replayable chosen-covertext attacks (SS-CCA) is achievable. Later, Hopper (ICALP 2005) provided such a stegosystem for every efficiently sampleable channel, but did not achieve universality. He posed the question whether universality and SS-CCA-security can be achieved simultaneously. No progress on this question has been achieved since more than a decade. In our work we solve Hopper's problem in a somehow complete manner: As our main positive result we design an SS-CCA-secure stegosystem that works for every memoryless channel. On the other hand, we prove that this result is the best possible in the context of universal steganography. We provide a family of 0-memoryless channels - where the already sent documents have only marginal influence on the current distribution - and prove that no SS-CCA-secure steganography for this family exists in the standard non-look-ahead model.Comment: EUROCRYPT 2018, llncs styl

Bounds on the deviation of a function from its averages

summary:Some generalizations of the Ostrowski inequality, the Milovanović-Pečarić-Fink inequality, the Dragomir-Agarwal inequality and the Hadamard inequality are given