Nursery pre‐treatment positively affects reintroduced plant performance via plant pre‐conditioning,but not via maternal effects

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Global drivers of reef fish growth

Few studies have attempted to understand how fish growth scales at community and macroecological levels. This study evaluated the drivers of reef fish growth across a large gradient of environmental variables and a range of morphological and behavioural traits. We compiled Von Bertalanffy Growth parameters for reef fishes and standardized K relative to species maximum sizes, obtaining K_max. We then modelled the response of K_max to body size, diet, body shape, position relative to the reef, schooling behaviour, sea surface temperature, pelagic net primary productivity and ageing method, while accounting for phylogenetic structure in the data. The final model explained 61.5% of the variation in K_max and contained size, temperature, diet, method and position. Body size explained 64% of the modelled K_max variability, while the other variables explained between 6% (temperature) and 2.5% (position). K_max steadily decreased with body size and increased with temperature. All else being equal, herbivores/macroalgivores and pelagic reef fishes had higher growth rates than the other groups. Moreover, length–frequency ageing tended to overestimate K_max compared to other methods (e.g. otolith's rings). Our results are consistent with (a) metabolic theory that predicts body size and temperature dependence of physiological rates; and (b) ecological theory that implies influence of resource availability and acquisition on growth. At last, we use machine learning to accurately predict growth coefficients for combinations of traits and environmental settings. Our study helps to bridge the gap between individual and community growth patterns, providing insights into the role of fish growth in the ecosystem process of biomass accumulation.     

Enhanced Heavy Metal Phytoextraction from Marine Dredged Sediments Comparing Conventional Chelating Agents (Citric Acid and EDTA) with Humic Substances

Metal (Cu, Mn, Ni, Zn, Fe) concentrations in marine sediment and zooplankton were investigated in Izmir Bay of the Eastern Aegean Sea, Turkey. The study aimed to assess the levels of metal in different environmental compartments of the Izmir Bay. Metal concentrations in the sediment (dry weight) ranged between 4.26–70.8 μg g^?1 for Cu, 233–923 μg g^?1 for Mn, 14.9–127 μg g^?1 for Ni, 25.6–295 μg g^?1 for Zn, 12,404–76,899 μg g^?1 for Fe and 38,226–91,532 μg g^?1 for Al in the Izmir Bay. Maximum metal concentrations in zooplankton were observed during summer season in the inner bay. Significant relationships existed between the concentrations of certain metals (Al, Fe, Mn and Ni) in sediment, suggesting similar sources and/or similar geochemical processes controlling such metals. Higher concentrations of Cu, Zn and percent organic matter contents were found in the middle-inner bays sediments. Based on the correlation matrix obtained for metal data, organic matter was found to be the dominant factor controlling Cu and Zn distributions in the sediment. In general, mean Cu and Zn levels in the bay were above background concentrations in Mediterranean sediments. Zooplankton metal concentrations were similar to sediment distributions.     

Silicon and salicylic acid in the physiology and yield of cotton

Silicon (Si) and salicylic acid (SA) foliar applications can benefit cotton yield especially if there is stress during cultivation. The objective of this study was to evaluate the foliar application of Si and SA on the photosynthetic variables and cotton yield. The experimental design used was randomized complete block, constituted by Si foliar application in potassium and sodium balanced silicate form (0 and 3.6?g L^?1 of Si) and SA (0 and 210?mg L^?1). The treatments were applied in three leaf sprays during the reproductive stage that coincided with water stress in tillage. Therefore, the Si foliar application associated with SA favors the physiological variables, increasing the photosynthesis, stomatal conductance and water use efficiency reflecting on the increase of cotton yield.     

Viral reinfection affecting bulb production in garlic after seven years of cultivation under field conditions

Six sequential field experiments were conducted from 1999 to 2002 to evaluate virus reinfection in garlic cv. Amarante and its effect on bulb production. The treatments in the year 1999 were: T₁ – virus-free garlic-seed obtained by thermotherapy and meristem-tip culture and indexed for virus by immuno-sorbent electron microscopy (ISEM) under its first field cycle; T₂, T₃ and T₄ – garlic-seed in the second, third and fourth field cycles, respectively; and C – standard garlic-seed from the grower (with no control of virus infection) as a control. In the years 2000 to 2002, a new plot of virus-free seed was added to the experiment and cloves from the previous treatments were again grown under field conditions. In the fourth year of experiments, the treatments comprised T₁ (virus-free garlic seeds under the first field cycle) to T₇ (garlic-seed in the sixth field cycle) and C. Two experiments were conducted in the years 1999 and 2000, at two locations and in the years 2001 and 2002 only one experiment per year at one location. The combined analysis of variance for all experiments indicated a significant difference between the treatments for plant height and yield. The bulbs were classified into commercial classes according the Brazilian regulation and the commercial classes 4–7 were 72 %, 60%, 59%, 53% and 35% of the total number of bulbs harvested, from T₁ to T₅, respectively. Virus reinfection at the end of the second field cycle, determined by serology using antisera against the most common viruses of garlic in Brazil reached 83%. Treatments T₁–T₇ yielded 118%, 79%, 57%, 51%, 39%, 33% and 31% higher than the control.     

Reorganisation of wood production for improved performance: a swiss forest district case study

An extremely fragmented timber supply, high harvesting costs, low profitability, high subsidies and insufficient competitiveness characterise forest enterprises in Switzerland. In a case study using a forest district in the state of Solothurn as an example, it was sought to identify strengths and weaknesses of wood production and to formulate possible improvement opportunities. The results indicate that there is considerable potential for industry rationalisation. The greatest handicaps are the small sized forest holdings, excessive numbers of staff, insufficient use of modern harvesting technology and costly business administration. The most eminent of the proposed improvement measures are those which aim to increase concentration of timber supplies and reduce production costs. These include greater centralising of timber sales as well as planning and steering of production, making full use of modern harvesting systems, reducing transaction costs, supporting administration, planning and steering of wood production with modern information technology and reducing input on stand tending. In principle, amelioration can be best achieved by close cooperation with neighbours or even merger of enterprises. Consequently, there is a need for related business tasks to be combined in functions. The paramount prerequisite for success is the willingness and readiness of all affected stakeholders to make changes. The situation described is typical for Swiss forestry and the proposed solutions could well be used as models for a wide range of Swiss forest districts.     

Hybridization despite elaborate courtship behavior and female choice in Neotropical tree frogs

The mechanisms of hybridization can be elucidated by analyzing genotypes as well as phenotypes that could act as premating barriers, as the reproductive interactions among heterospecifics can alter the evolutionary history of species. In frogs, hybrids typically occur among species that reproduce explosively (in dense aggregations) with few opportunities for mate selection but are rare in species with elaborate courtship behaviors that may prevent erroneous mating. Using 21 microsatellite markers, we examined hybridization in the prolonged-breeding tree frogs Bokermannohyla ibitiguara and B. sazimai sampled within a contact zone in the Brazilian savanna (72 tadpoles; 74 adults). We also compared acoustic and morphological data. We confirmed both parental species genetically; STRUCTURE results confirmed 14 hybrids, 11 of which were second-generation according to NEWHYBRIDS, all with intermediate values of genetic dissimilarities compared to the parentals. Morphological and acoustic analyses revealed that hybrids showed variable but not necessarily intermediate phenotypes. Moreover, 2 hybrids exhibited call types different from parentals. The reproduction of B. ibitiguara involves territorial and aggressive males, elaborate courtships with acoustic and tactile stimuli, choosy females, and opportunistic strategies. Our study uncovers a rare case of viable hybridization among closely related frogs with such a combination of complex courtship behaviors and mate choice. We discuss the likely directionality and mechanisms behind this phenomenon, and highlight the importance of investigating hybridization even in species that show elaborate reproduction and female choice to advance our understanding of animal diversification.     

Granulomatous nephritis in psittacines associated with parasitism by the trematode Paratanaisia spp

Trematodes belonging to the family Eucotylidae are parasites of the kidney and ureter, and affect several bird species. However, psittacines have not been identified as hosts of these parasites. Three birds, an adult female blue and gold macaw (Ara ararauna), an adult female blue-winged macaw (Propyrrhura maracana) and an adult male white-eared parakeet (Pyrrhura leucotis) were admitted at the Veterinary Hospital of the Funda??o Zoo-Botanica de Belo Horizonte, Brazil (FZB/BH). All three birds had severe dehydration and cachexia. The blue and gold macaw presented with dyspnea, apathy, and incoordination. Blood cell counts indicated discrete anemia and leucopenia. Blood biochemistry revealed significant increase in levels of uric acid (61 mg/dl) and blood urea nitrogen (22 mg/dl). The bird died within 24 h after admission. The other two birds were admitted with similar clinical signs, but died prior to a complete clinical examination. At the necropsy, in all the three birds, the kidneys were enlarged with brown-yellowish discoloration and irregular cortical surface. On the cut surface, there was a brown-yellowish material with few visible parasites flowing out of the parenchyma. When fragments of the kidneys were placed in 10% formalin, a large number of trematodes came out of the renal parenchyma. The parasites were identified as Paratanaisia robusta infecting all three birds, and P. bragai infecting the blue-winged macaw and the white-eared parakeet. Histologically, there was an interstitial, multifocal to coalescent, lymphoplasmacytic infiltrate with some epithelioid macrophages, and a few heterophils, characterizing a granulomatous nephritis. Adult worms and eggs were observed within dilated tubules and in the renal pelvis. In the blue and gold macaw, some parasite eggs were located interstitially associated with an intense adjacent granulomatous reaction.     

Anticancer activities of two sesquiterpene lactones, millerenolide and thieleanin isolated from Viguiera sylvatica and Decachaeta thieleana

The present study was carried out in order to examine the anticancer properties of two sesquiterpene lactones, millerenolide and thieleanin, isolated from Viguiera sylvatica and Decachaeta thieleana, against cell lines in vitro, and on the growth B16/BL6 melanoma tumors in C57BL/6 mice. Millerenolide and thieleanin showed a similar pattern of cytotoxicity with the greatest effect on viability being evident with A549 human lung cancer cells (IC(50) - 40 and 32 microM respectively), and with the 3T3/HER2 cell line which are 3T3 mouse fibroblasts transfected with the HER2 oncogene (IC(50) - 16 and 28 microM respectively). The parent 3T3 cells and the B16/BL6 mouse melanoma cells were less sensitive to these compounds, with thieleanin showing an IC(50) with B16/BL6 greater than the highest dose tested (203 microM). Treatment with millerenolide (8 mg/kg, i.p. on days 0, 2 and 4 post-inoculation) significantly inhibited the growth of subcutaneous B16/BL6 tumors in C57BL/6 mice, (50% inhibition at day 25, P=0.015), as well as retarding the appearance of detectable tumor (millerenolide - day 15.2+/-0.4 vs control - day 12.8+/-0.5, mean+/-SEM, P=0.011). In contrast, treatment with thieleanin (8 mg/kg every other day up to the day of kill) neither retarded the appearance of the tumor nor its growth.     

Phytotoxic effect of culture filtrate from Fusarium subglutinans the causal agent of fusariose of pineapple (Ananas comosus (L.) Merr

Two pineapple varieties differing in resistance to fusariose were examined for the phytotoxic effect of Fusarium subglutinans culture filtrate. The cultivars were Perolera (more resistant to pathovars of Fusarium subglutinans) and Smooth Cayenne (more susceptible). The phytotoxic effect of culture filtrate was assessed in tissue culture pineapple plantlets (by electrolyte leakage and placing the culture filtrate on wound leaf segments) and callus (inhibition of growth). Smooth Cayenne proved to be the most sensitive cultivar in each test, whereas Perolera showed resistance to the culture filtrate and its callus grew in the presence of high concentrations of culture filtrate that were completely toxic to Smooth Cayenne. These results show that plants can display cellular resistance to the culture filtrate. This revised version was published online in August 2006 with corrections to the Cover Date.