Retardadores de crescimento no desenvolvimento e na qualidade ornamental de Zinnia elegans Jacq. 'Lilliput' envasada

As zínias têm grande potencial como plantas floríferas envasadas e representam rápida fonte de novidade para a floricultura com o auxílio de retardadores de crescimento. Avaliaram-se os efeitos de retardadores de crescimento no desenvolvimento e na produção de plantas envasadas de porte baixo, compactas e atrativas de 'Lilliput' Zinnia elegans, cultivar altamente ornamental, com sementes de baixo custo. O delineamento experimental foi em blocos casualizados, com dez tratamentos (controle e três concentrações de cada retardador: daminozide, paclobutrazol e chlormequat) e quatro repetições (dois vasos por unidade experimental, com uma planta por vaso de 0,6 L). Paclobutrazol (0,5; 0,75 e 1,0 mg i.a. por vaso) e chlormequat (1,0; 2,0 e 3,0 g L-1) foram aplicados ao substrato (40 mL por vaso), enquanto o daminozide (2,5; 3,75 e 5,0 g L-1) foi aplicado através de pulverização foliar (10 mL por vaso), no estádio de gema floral apical visível. Daminozide (2,5 e 3,75 g L-1), paclobutrazol (0,5; 0,75 e 1,0 mg i.a. por vaso) e 1,0 g L-1 de chlormequat reduziram significativamente a altura das plantas e o comprimento dos ramos laterais, sem afetar o diâmetro dos capítulos, atrasar o ciclo de produção e causar fitotoxicidade. Entretanto, as plantas não se apresentaram suficientemente baixas e compactas para atender às exigências de qualidade do mercado. Chlormequat (2,0 e 3,0 g L-1) causou fitotoxicidade e daminozide (5,0 g L-1) aumentou o ciclo de produção.Zinnias have good potential to be used as flowering, potted plants, being a quick source of novelty for the floriculture industry with the aid of growth retardants. This study evaluated the effect of growth retardants on development and production of short, compact and attractive plants of potted 'Lilliput' Zinnia elegans, a highly ornamental zinnia with low cost seeds. Trials were set up in randomized blocks, with ten treatments (control and three treatments of each retardant: daminozide, paclobutrazol and chlormequat) and four replications (two pots per experimental unit, with one plant per 0.6-L pot). Paclobutrazol (0.5, 0.75 and 1.0 mg a.i. per pot) and chlormequat (1.0, 2.0 and 3.0 g L-1) were applied as a single drench (40 mL per pot), and daminozide (2.5, 3.75 and 5.0 g L-1) as a single foliar spray to runoff (10 mL per pot), at apical flower bud stage. Daminozide (2.5 and 3.75 g L-1), paclobutrazol (0.5, 0.75 and 1.0 mg a.i. per pot) and chlormequat at 1.0 g L-1 significantly reduced plant height and side branches length, without affecting flower diameter, delaying production cycle and causing phytotoxicity symptoms. However, plants were not short and compact enough to meet market quality demand. Chlormequat (2.0 and 3.0 g L-1) caused phytotoxicity symptoms and daminozide (5.0 g L-1) delayed production cycle

Combination of contrast with stress echocardiography: A practical guide to methods and interpretation

Contrast echocardiography has an established role for enhancement of the right heart Doppler signals, the detection of intra-cardiac shunts, and most recently for left ventricular cavity opacification (LVO). The use of intravenously administered micro-bubbles to traverse the myocardial microcirculation in order to outline myocardial viability and perfusion has been the source of research studies for a number of years. Despite the enthusiasm of investigators, myocardial contrast echocardiography (MCE) has not attained routine clinical use and LV opacification during stress has been less widely adopted than the data would support. The purpose of this review is to facilitate an understanding of the involved imaging technologies that have made this technique more feasible for clinical practice, and to guide its introduction into the practice of the non-expert user

Protection of Melanized Cryptococcus neoformans from Lethal Dose Gamma Irradiation Involves Changes in Melanin's Chemical Structure and Paramagnetism

Certain fungi thrive in highly radioactive environments including the defunct Chernobyl nuclear reactor. Cryptococcus neoformans (C. neoformans), which uses L-3,4-dihydroxyphenylalanine (L-DOPA) to produce melanin, was used here to investigate how gamma radiation under aqueous aerobic conditions affects the properties of melanin, with the aim of gaining insight into its radioprotective role. Exposure of melanized fungal cell in aqueous suspensions to doses of γ-radiation capable of killing 50 to 80% of the cells did not lead to a detectable loss of melanin integrity according to EPR spectra of melanin radicals. Moreover, upon UV-visible (Xe-lamp) illumination of melanized cells, the increase in radical population was unchanged after γ-irradiation. Gamma-irradiation of frozen cell suspensions and storage of samples for several days at 77 K however, produced melanin modification noted by a reduced radical population and reduced photoresponse. More direct evidence for structural modification of melanin came from the detection of soluble products with absorbance maxima near 260 nm in supernatants collected after γ-irradiation of cells and cell-free melanin. These products, which include thiobarbituric acid (TBA)-reactive aldehydes, were also generated by Fenton reagent treatment of cells and cell-free melanin. In an assay of melanin integrity based on the metal (Bi+3) binding capacity of cells, no detectable loss in binding was detected after γ-irradiation. Our results show that melanin in C. neoformans cells is susceptible to some damage by hydroxyl radical formed in lethal radioactive aqueous environments and serves a protective role in melanized fungi that involves sacrificial breakdown

Rates of fixation by lightning of carbon and nitrogen in possible primitive atmospheres

A thermochemical-hydrodynamic model of the production of trace species by electrical discharges has been used to estimate the rates of fixation of C and N by lightning in the primitive atmosphere. Calculations for various possible mixtures of CH 4 , CO 2 , N 2 , H 2 , and H 2 O reveal that the prime species produced were probably HCN and NO and that the key parameter determining the rates of fixation was the ratio of C atoms to O atoms in the atmosphere. Atmospheres with C more abundant than O have large HCN fixation rates, in excess of 10 17 molecules J −1 , but small NO yields. However, when O is more abundant than C, the NO fixation rate approaches 10 17 molecules J −1 while the HCN yield is small. The implications for the evolution of life are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43346/1/11084_2004_Article_BF00931483.pd

Wplyw rodzaju podloza na plonowanie pomidora drobnoowocowego [Lycopersicon esculentum var.cerasiforme] w uprawie szklarniowej

Dwie odmiany pomidora drobnoowocowego (Conchita, Favorita) uprawiano na wełnie mineralnej i matach włókna kokosowego Cocovita w cyklu wiosenno-letnim i jesiennym w szklarni. Otrzymane wyniki wskazują, że wełna mineralna była lepszym podłożem w uprawie pomidora drobnoowocowego, zwłaszcza w cyklu wiosenno-letnim, gdzie plon handlowy owoców był istotnie wyższy niż z uprawy na włóknie kokosowym. Odmiana Conchita zdecydowanie gorzej plonowała na podłożu kokosowym, natomiast odmiana Favorita dała istotnie wyższy plon wczesny. Rodzaj podłoża nie miał istotnego wpływu na średnią liczbę owoców wiązanych przez roślinę pomidora. Niemniej jednak odmiana Favorita wiązała ich więcej w uprawie na włóknie kokosowym, szczególnie istotnie więcej w cyklu wiosenno-letnim. Natomiast liczba owoców w gronie była mniejsza u roślin uprawianych na włóknie kokosowym. Rodzaj podłoża, odmiana, sezon uprawy miały wpływ na średnia masę owoców.Two cultivars of cherry tomato (Conchita, Favorita) were grown on rock wool and coir straw slabs (Cocovita) in spring-summer and autumn cycles under glass. Obtained results showed that rockwool was a better growing medium for cherry tomato especially in spring-summer cycle when marketable yield of fruits was significantly higher than on coir straw. Conchita cv. explicitly yielded worse on coir straw than Favorita cv., which gave significantly higher early yield of fruits on this growing medium. Type of substrate did not have influence on the average number of fruits in tomato plant. Nevertheless, Favorita cv. set more fruits per one plant grown on coir straw especially significantly more in spring-summer cycle. Number of fruits per one truss was lower in plants grown on coir straw than on rockwool. Type of growing medium, cultivar, season of cultivation had influence on the mean weight of cherry tomato fruits