Reactions at interfaces as a source of sulfate formation in sea-salt particles   总被引：1，自引：0，他引：1  

Laskin A  Gaspar DJ  Wang W  Hunt SW  Cowin JP  Colson SD  Finlayson-Pitts BJ 《Science (New York, N.Y.)》2003,301(5631):340-344

Understanding the formation of sulfate particles in the troposphere is critical because of their health effects and their direct and indirect effects on radiative forcing, and hence on climate. Laboratory studies of the chemical and physical changes in sodium chloride, the major component of sea-salt particles, show that sodium hydroxide is generated upon reaction of deliquesced sodium chloride particles with gas-phase hydroxide. The increase in alkalinity will lead to an increase in the uptake and oxidation of sulfur dioxide to sulfate in sea-salt particles. This chemistry is missing from current models but is consistent with a number of previously unexplained field study observations.  相似文献   

Biometrics,Testosterone, Cortisol and Antler Growth Cycle in Iberian Red Deer Stags (Cervus elaphus hispanicus)     

E Gaspar‐López  T Landete‐Castillejos  JA Estevez  F Ceacero  L Gallego  AJ García 《Reproduction in domestic animals》2010,45(2):243-249

In this article, we aimed to describe the changes related to mating season in red deer, especially those related to antler growth, body condition score, testosterone and cortisol. Antler growth was studied in 17 Iberian red deer males, including body weight, antler length, biometric measures and testosterone and cortisol determination during 15 months. Body weight, body condition score, thoracic perimeter (TP), neck perimeter (NL) and testicular diameter (TD) showed the highest values immediately before mating season (autumn), decreased during it and remained constant at winter. Antler growth lasted 158 days and produced antlers with a final length of 80.8 ± 2.0 cm. Testosterone and cortisol showed seasonal changes with maximum values at September and May, respectively. Final antler size was related positively to cranial longitude, TP, NL, TD and body weight at casting time. No relationship between weight loss during precedent mating season and current antler size was found, but spring recovery weight was positively related to final antler size. Final length was related to the descent in testosterone values during previous mating season and to body weight before it. Spring recovery weight was related to relative weight loss during previous mating season. These results suggest that there is no relationship between the reproductive effort performed during one season and the next year size of the antler. In contrast, antler size was positively related to spring recovery weight, in the sense that those deer that recover a higher percentage of body weight at the early stages of antler growth develop higher antlers.  相似文献   

Methods of adding micronutrients to a NPK formulation and maize development     

Gustavo Alves Santos  Gaspar Henrique Korndörfer  Hamilton Seron Pereira 《Journal of plant nutrition》2016,39(9):1266-1282

Micronutrients are essential for plant development; however, micronutrient content in soil often is not sufficient. This study compared availability of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in the soil and their effect in developing maize plants, supplied from a physical mixture of nitrogen, phosphorus, and potassium (NPK) granules and micronutrients or from a granulated mixture of NPK coated with these micronutrients. The experiment was conducted in a greenhouse, with a Rhodic Acrustox soil and the formulation 4-30-10 [nitrogen-phosphorus pentoxide-potassium oxide (N-P₂O₅-K₂O)] with 0.1% B, 0.2% Cu, 0.2% Mn, and 0.3% Zn. A randomized block design with four replicates was used and the NPK formula doses used were 0, 150, 300, 600, 1200, and 2400 kg/ha. Coated NPK increased Zn levels in soil in 0.5 mg/dm³ in relation to its initial content, also causing an increase in plant dry matter. Compared with mixture, this increase was more than three times greater. Cu and Zn accumulation and Zn absorption were greater when their supply was made via coated granules. The larger dose of B via coated granules resulted in a greater B accumulation in comparison to the mixture. No differences were observed for the other variables when comparing both sources. Coating NPK granules with micronutrients was better than the mixture when comparing B, Cu, and Zn concentrations in the soil. Dry matter production of maize shoots and the accumulation of B, Mn, Cu, and Zn in it was greater when the fertilizer was coated with micronutrients.  相似文献   

Phytophthora ×alni and Phytophthora lacustris associated with common alder decline in Central Portugal          下载免费PDF全文

M. Kanoun‐Boulé  T. Vasconcelos  J. Gaspar  S. Vieira  C. Dias‐Ferreira  C. Husson 《Forest Pathology》2016,46(2):174-176

Since the early 1990s, an emerging disease induced by the highly aggressive oomycete Phytophthora ×alni has caused widespread alder decline across Europe. In parallel, P. lacustris, a recently described species associated with riparian habitats, has been subject of increasing interest. A field survey conducted in 2014 showed high mortality rates in alder stands located in the riparian gallery along two rivers in Central Portugal. The pathogens isolated from necrotic alder stem base during this study were identified as P. ×alni and P. lacustris. This paper is the first to report the occurrence of P. lacustris in Portugal and presents the first finding of P. ×alni affecting mature trees in natural ecosystems located in Central Portugal.  相似文献   

Fate of 210Pbex fallout in soil under forest and scrub of the central Spanish Pre‐Pyrenees          下载免费PDF全文

L. Gaspar  R. Webster  A. Navas 《European Journal of Soil Science》2017,68(3):259-269

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Effect of dietary seaweed supplementation on growth performance,antioxidant and immune responses in European seabass (Dicentrarchus labrax) subjected to rearing temperature and salinity oscillations     

Lobo  Gaspar  Pereira  Luís F.  Gonçalves  José F. M.  Peixoto  Maria J.  Ozório  Rodrigo O. A. 《International Aquatic Research》2018,10(4):321-331

The current study evaluated the effects of dietary seaweed supplementation in European seabass juveniles (Dicentrarchus labrax) subjected to rearing temperature and salinity oscillations, simulating natural variations in pond aquaculture conditions. Two experimental diets where formulated: a control diet (CTRL) with no supplementation and one supplemented with 7.5% seaweed mix (SW 2.5% Fucus sp., 2.5% Gracilaria sp. and 2.5% Ulva sp.). Seabass from both dietary groups (40.7 g initial body weight) was subjected to either combined salinity and temperature oscillations, or to fixed conditions. Growth performance, innate immune, and oxidative stress responses were evaluated. Results showed that seaweed supplementation had no significant effect on the analyzed parameters. However, environmental oscillations revealed significant effects on growth performance and oxidative stress response. Fish subjected to salinity and temperature oscillations had a significantly lower weight gain and daily growth index than those subjected to fixed conditions, regardless of dietary treatment. Total glutathione, oxidized glutathione, and catalase increased in fish subjected to oscillatory conditions. Lysozyme and peroxidase were not influenced by either diet or environmental conditions. In conclusion, this particular dietary seaweed mix supplementation did not mitigate the negative effects of environmental oscillations on growth performance and innate immune responses in European seabass.

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Peroxidase and isoperoxidase changes in relation to root initiation of Asparagus cultured in vitro     

P. Van Hoof  Th. Gaspar 《Scientia Horticulturae》1976,4(1):27-31

Rhizogenesis of Asparagus stem segments in vitro is accompanied by a decrease in total peroxidase activity. The activity of the two extreme anodic isoperoxidases increases while that of the four most cathodic ones decreases. These biochemical events take place in the upper part of the cutting as well as in the rooting region.Cuttings from Asparagus plants which root more easily than others can be distinguished by their higher peroxidase activity in parallel with a greater activity in their anodic (the two extreme ones) and cathodic (the four extreme ones) isoperoxidases.It is suggested that this type of peroxidase analysis may be used as a test for the selection of mother plants with a high root-forming ability.  相似文献   

Does selecting for improved growth affect wood quality of Pinus pinaster in Portugal?     

Maria João Gaspar  José Luís Lousada  José Carlos Rodrigues  Alexandre Aguiar  Maria Helena Almeida 《Forest Ecology and Management》2009

The selection criteria for the first generations in the Portuguese Pinus pinaster improvement program have been the growth rate and form traits. In this work we study the consequences of this selection on wood quality traits. This study assesses genetic and phenotypic correlation between growth, wood density components, lignin content and mechanical traits (radial modulus of elasticity and radial modulus of rupture) of 46 half sib families from a progeny trail located in Leiria, Portugal, originated from seed collected in a clonal seed orchard. A total of 552 seventeen-years-old trees (about half of full rotation age) were sampled at 2 m height. Height measured at 12 years old presented a higher genetic control (h² = 0.34) relatively to DBH, measured at 12 and 17 years old respectively (h² = 0.17 and h² = 0.15). The results of this study also showed that DBH growth is more dependent on latewood components than earlywood components and that higher growth in Mediterranean regions can be due to an increase of the period of latewood formation. Further, we can conclude genetic selection based on growth will not result in a decrease of wood density, will not affect the occurrence of spiral grain, and is possible to obtain an increase in the radial modulus of elasticity. The present study also showed that it is possible to select for increased growth with lower lignin proportion. Results also suggest that selection for growth at 12 years will probably not affect negatively the wood properties at 17 years.  相似文献   

Yield determination in triticale as affected by radiation in different development phases   总被引：4，自引：0，他引：4  

Gaspar Estrada-Campuzano  Daniel J. Miralles  Gustavo A. Slafer 《European Journal of Agronomy》2008,28(4):597-605

The critical period for grain yield determination has not been determined for triticale. We aimed to identify it, determining the relative importance of both the major yield components and the dry matter acquisition by the spikes at anthesis. A field experiment was carried out with two triticales, differing in tillering capacity, subjected to shading treatments at five different timings from early tillering to maturity. Results showed that reductions in grain yield were more significant when shading was imposed during 3 weeks before and 1 week after anthesis. Reductions in grain yield by shading treatments were associated with lower number of grains per m² more than with changes in the average grain weight. Reductions in grains per m² were due to reductions in the number of fertile florets per spike, affecting grains per spike. The assimilate acquisition by the spikes during the critical period was a key determinant of floret survival. Grain number per m² was related with photothermal quotient during 30 days before anthesis and spike dry weight at anthesis, though the goodness of the prediction compared with wheat, was lowered by poorer grain setting percentage.  相似文献   

Economic and management characterization of dehesa farms: implications for their sustainability     

P. Gaspar  F. J. Mesías  M. Escribano  A. Rodriguez de Ledesma  F. Pulido 《Agroforestry Systems》2007,71(3):151-162

Dehesa agroforestry systems occupy around 6 million ha in the Iberian Peninsula. Their economic and environmental sustainability depends on the maintenance of the extensive livestock farms which created this typical ecosystem. This work analyzes dehesa farms in the Extremadura region (SW Spain) using technical and economic indicators of 69 randomly selected holdings. Principal component analysis (PCA) allowed us to establish a valid model explaining 65.8% of the variance. The two principal components having most weight were Iberian pig production (explaining 20% of the variance of the model), and which ruminant species were raised on the farm (15% of the variance). A cluster analysis distinguished five types of farms: sheep farms at high and low stocking rates, beef cattle farms, wooded farms with mixed livestock, and farms with a high level of cropping activity. The most profitable farms were those with either high overall livestock density or a high level of Iberian pig production. While high stocking density has historically attracted high levels of subsidy, production of Iberian pigs was profitable because of the high value of the product. In the light of CAP reform, Iberian pig production seems the most readily sustainable type of farming for the dehesa system.

F. J. MesíasEmail:

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