13 research outputs found
Anti-Apoptotic Machinery Protects the Necrotrophic Fungus Botrytis cinerea from Host-Induced Apoptotic-Like Cell Death during Plant Infection
Necrotrophic fungi are unable to occupy living plant cells. How such pathogens survive first contact with living host tissue and initiate infection is therefore unclear. Here, we show that the necrotrophic grey mold fungus Botrytis cinerea undergoes massive apoptotic-like programmed cell death (PCD) following germination on the host plant. Manipulation of an anti-apoptotic gene BcBIR1 modified fungal response to PCD-inducing conditions. As a consequence, strains with reduced sensitivity to PCD were hyper virulent, while strains in which PCD was over-stimulated showed reduced pathogenicity. Similarly, reduced levels of PCD in the fungus were recorded following infection of Arabidopsis mutants that show enhanced susceptibility to B. cinerea. When considered together, these results suggest that Botrytis PCD machinery is targeted by plant defense molecules, and that the fungal anti-apoptotic machinery is essential for overcoming this host-induced PCD and hence, for establishment of infection. As such, fungal PCD machinery represents a novel target for fungicides and antifungal drugs
Short- and long-term compressive strength of mortars modified with hardening accelerating admixtures
W artykule zaprezentowano wyniki badań wytrzymałości na ściskanie zapraw wykonanych z cementu portlandzkiego i cementu z dodatkiem mielonego granulowanego żużla wielkopiecowego. Zaprawy zostały poddane modyfikacji domieszkami przyspieszającymi twardnienie o różnych bazach chemicznych. Wytrzymałość na ściskanie badana była w terminach od 12 godzin do 360 dni. Zauważono, że efektywność działania domieszek jest wyższa dla cementu z dodatkiem żużla w terminie do 28 dni. Po tym terminie niektóre domieszki również korzystnie wpływają na wytrzymałość tych zapraw. Wykazano, że nie można jednoznacznie stwierdzić, że każda domieszka przyspieszająca powoduje obniżenie długoterminowej wytrzymałości na ściskanie zapraw wykonanych z niektórych rodzajów cementu. Zaprawy z cementu z dodatkiem MGŻW, modyfikowane domieszkami przyspieszającymi, osiągają wytrzymałość zbliżoną do końcowej już po 7 dniach, w czym upodabniają się (zachowując oczywiście skalę) do niemodyfikowanej zaprawy z CEM I 52,5R.This paper presents results of compressive strength tests for Portland cement mortars and mortars with addition of ground granulated blast furnace slag (GGBFS). Mortars were modified with usage of four different hardening accelerating admixtures. Compressive stress tests were conducted after 12 hours up to 360 days of curing. Effectiveness of those agents is higher for mortars made of cement with addition of GGBFS up to 28th day. After this term some of those admixtures have profitable influence also. It is shown that not every hardening accelerating admixture cause decline of long-term compressive strength of mortars made of some types of cement. Mortars with addition of GGBFS obtains compressive strength after 7 days of curing close to its final strength. It is similarity to CEM I 52,5R mortars without modification by admixtures (with notice to scale of phenomenon)
Compatibility of air-entraining and water-reducing admixture in case of cement based mixtures
Badania przeprowadzone przez autorów wykazały, że w przypadku konieczności upłynnienia uprzednio napowietrzonej
mieszanki cementowej, występuje problem zachowania odpowiedniego jej napowietrzenia. Większość spośród dostępnych
domieszek upłynniających powoduje znaczące zwiększenie napowietrzenia mieszanek betonowych. Analiza rezultatów
przeprowadzonych badań wykazała także, że na wielkość napowietrzenia mieszanek cementowych wpływa również
kolejność dozowania domieszek napowietrzającej i upłynniającej. Zatem kompatybilność takich domieszek z cementem,
ze względu na wymagane napowietrzenie i konsystencję mieszanki, zależy nie tylko od ich współdziałania, ale także
od procedury ich dozowania.Research conducted by the authors showed that if it is necessary to increase the degree of liquidity of previously aerated
a cementitious mixtures, there is the problem of maintaining their correct aeration. Most of the available water-reducing
admixtures cause a significant increase of air content of concrete mixtures. Analysis of the results of the research also
showed that the air content of cement mixes is influenced by the sequence of the dosing of air-entraining and waterreducing
admixtures. Thus, the compatibility of these admixtures with the cement, due to the required air entrainment and
consistency of the mixture, not only depends on their interaction, but also on the dosing procedure
Factors affecting the suitability of superplasticiser-amended cement for the encapsulation of radioactive waste
Drought-induced susceptibility for Cenangium ferruginosum leads to progression of Cenangium-dieback disease in Pinus koraiensis
Effect of vinyl acetate effluent in reducing heat of hydration of concrete
Waste generation especially in surface coating industries is a potential pollutant to the environment globally. Waste disposal in the form of recycling or reused has gained some recognition as a raw material in many kind of interested fields. This study is therefore, aimed at utilizing Vinyl acetate effluent generated from manufacturing process of paint as polymer modifier in concrete. The research highlights the influence of Vinyl acetate effluent on setting time and control of heat of hydration in concrete. Three specimens containing 0%, 2.5% and 5% of Vinyl acetate effluent by weight of cement were prepared in cubic moulds. The temperature rises due to heat of hydration in all mixes were recorded. Finding shows that incorporating Vinyl acetate effluent considerably delayed the setting time in cement paste and reduced the total temperature rise in polymer modified concrete. Therefore, addition of Vinyl acetate effluent polymer in concrete may improve the properties of concrete to some extent particularly in mass concrete production