A shorter 146Sm half-life measured and implications for 146Sm-142Nd chronology in the solar system     

Kinoshita N  Paul M  Kashiv Y  Collon P  Deibel CM  DiGiovine B  Greene JP  Henderson DJ  Jiang CL  Marley ST  Nakanishi T  Pardo RC  Rehm KE  Robertson D  Scott R  Schmitt C  Tang XD  Vondrasek R  Yokoyama A 《Science (New York, N.Y.)》2012,335(6076):1614-1617

The extinct p-process nuclide (146)Sm serves as an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its α-decay daughter (142)Nd. Based on analyses of (146)Sm/(147)Sm α-activity and atom ratios, we determined the half-life of (146)Sm to be 68 ± 7 (1σ) million years, which is shorter than the currently used value of 103 ± 5 million years. This half-life value implies a higher initial (146)Sm abundance in the early solar system, ((146)Sm/(144)Sm)(0) = 0.0094 ± 0.0005 (2σ), than previously estimated. Terrestrial, lunar, and martian planetary silicate mantle differentiation events dated with (146)Sm-(142)Nd converge to a shorter time span and in general to earlier times, due to the combined effect of the new (146)Sm half-life and ((146)Sm/(144)Sm)(0) values.  相似文献   

Influence of oak wood on the aromatic composition and quality of wines with different tannin contents   总被引：3，自引：0，他引：3  

Díaz-Plaza EM  Reyero JR  Pardo F  Alonso GL  Salinas MR 《Journal of agricultural and food chemistry》2002,50(9):2622-2626

The aromatic compounds associated with aging in wood have been studied in Monastrell wines containing different quantities of tannin. Analyses were carried out before and after a six month period in wooden barrels (225 L) of American and French (Allier) medium-toasted oak. Three classes of wine were made: one from a free-run must; one to which enological tannin was added; and one to which was added the wine obtained by pressing the grape pomaces. The aromas were determined by GC-MS, and the quality was evaluated by a group of expert tasters. The aromatic compounds, some of which came from the wines themselves and others which came from the wood, all increased in concentration by the end of the aging process. The ratio between cis- and trans-whiskylactone contents in wines reflected the different types of oak wood used. The note "vanilla" used by the tasters is probably not totally due to the presence of vanillin. The wines of best quality were those with a natural tannin content which had been aged in American oak, whereas the wines to which enological tannin had been added but aged in the same wood were considered the worst. An equalizing effect on the sensorial wines qualities was seen to result from the use of French oak. The furfural, eugenol, and cis-, and in some cases trans-, whiskylactone contents identified the wines from the different classes of wood. The wood from which the barrels were made had a greater effect on wines differentiation than the tannin content.  相似文献   

Morphological and pathogenic characterization of Corynespora cassiicola isolates reveals specific genotypic interactions in soybean     

María Laura Toulet  Diego A. Neira  Marcela Escobar  E. Mariano Pardo  Marta E. Arias  Leonardo Daniel Ploper  Björn Welin  Atilio Pedro Castagnaro  Nadia Regina Chalfoun 《Plant pathology》2022,71(4):843-859

Soybean target spot, caused by the fungus Corynespora cassiicola, is an important disease in northwestern Argentina (NWA). A cultural, morphological, and virulence characterization of 24 C. cassiicola isolates from different geographic localities in NWA was performed. The isolates were classified into five different cultural phenotypes, one of which has not been previously described. The ribosomal DNA internal transcribed spacer region sequence from five representative isolates (587 bp) exhibited 100% identity with C. cassiicola. A high variability of conidial morphology was observed among isolates, but no correlation with cultural phenotype was observed. When the soybean cultivar A 8000 RG was challenged with the 24 isolates, different degrees of virulence were observed, ranging from highly virulent to nonvirulent. No association of virulence with cultural or morphological characters was observed, but a relationship with geographical origin was demonstrated. Histopathological studies were performed on a nonvirulent and a highly virulent isolate. Microscopic observations of infected tissues of the former showed low mycelium development restricted to the upper epidermis, a thickening of the cuticle and primary wall of subepidermal cells, and accumulation of callose in phloematic vessels. In tissue infected with the latter, there was abundant mycelium development accompanied by cellular disorganization in mesophyll cells. Pathological challenges of isolates on nine different cultivars indicated that the degree of virulence of isolates depends on the plant genotype, demonstrating that the C. cassiicola–soybean interaction is highly specific. Understanding the genetic basis of this interaction will provide new information for better disease management and breeding strategies.  相似文献   

Patterns of nitrate loss from a chronosequence of clear-cut watersheds     

L. H. Pardo  C. T. Driscoll  G. E. Likens 《Water, air, and soil pollution》1995,85(3):1659-1664

Three clear-cuts at the Hubbard Brook Experimental Forest (NH) have resulted in a chronosequence of forest watersheds in close proximity. Following clear-cutting, the stands, now 12, 21, 27, and 78 years old, have different species composition, nutrient capital, and biogeochemistry. In this study, we compared seasonal patterns of NO₃ ^– in streamwater, changes in N capital, and N retention in watersheds of differing stand age. All of the watersheds showed elevated losses of NO₃ ^–, H⁺ and nutrient cations (Ca²⁺, Mg²⁺, K⁺) during the first few years following clear-cutting. Increased retention of N occurred during vegetation regrowth compared to the reference watershed (W6). Nitrate concentrations were low during the summer growing season, increased in the late fall and peaked in March during spring snowmelt. Concentrations of NO₃ ^– were lower in the regrowing watersheds than in W6 during all months. In W6, there was considerable year-to-year variability in N retention, which was not initially observed in the manipulated watersheds. However, two cut watersheds exhibited higher export of NO₃ ^– in 1989 and 1990, corresponding to a 10-year high value in annual NO₃ ^– loss in W6. These results demonstrate the importance of land use and cutting history in assessments of N saturation and loss from forest watersheds.  相似文献   

Use of pyloroplasty (Y-U) to treat presumed delayed gastric emptying in a cheetah (Acinonyx jubatus).     

D L Neiffer  A D Pardo  E C Klein 《Journal of zoo and wildlife medicine》2000,31(4):552-557

A 4-yr-old cheetah (Acinonyx jubatus) with a 2-yr history of chronic intermittent vomiting and spiral bacteria-associated gastritis presented with dramatically increased vomiting frequency and marked intermittent abdominal distention. Physical examination revealed loss of muscle mass and poor fur coat quality. Contrast radiography was consistent with delayed gastric emptying due to presumed gastric outlet obstruction. Both Y-U pyloroplasty and incisional gastropexy were performed, and no subsequent vomiting has been observed for 3 yr with the exception of three episodes during the immediate postoperative period. The cause of delayed gastric emptying was not determined, although a gastric motility disorder associated with gastric bacterial infection and elevated gastrin levels was suspected.  相似文献   

Relation of peel damage in citrus fruit to wind climate in orchard and its control     

Alfredo Gravina  José Cataldo  Giuliana Gambetta  Elisa Pardo  Cecilia Fornero  Sebastián Galiger  Rodolfo Pienika 《Scientia Horticulturae》2011

Peel damage originated by wind is the main abiotic cause of citrus fruit discards for export in Uruguay. Natural windbreaks such as Eucalyptus and Casuarinas have not been effective in reducing it. This research was carried out during three years in a citrus orchard situated in the coastal plain of Uruguay (35° SL). The purpose of this work was to study wind climate inside the orchard, fruit seasonal sensitivity, basal leaf effect on the onset and evolution of peel damage, and the efficiency of artificial windbreaks to reduce fruit discard of ‘Ellendale’ tangor. Average wind velocity in the orchard did not exceed 5 m s⁻¹. First peel scars were evident two weeks after petal fall and damaged fruit percentage importantly increased during the first stage of fruit growth. Low energy vortexes caused almost permanent friction between basal leaves and the developing fruitlets growing in their axil. Removal of the basal leaf decreased significantly wind damaged fruit. Natural wind flow modification through the use of semi-porous artificial windbreak nets (5 cm by 10 cm mesh) modified low energy vortexes and increased significantly the percentage of export quality fruit. We conclude that this type of net is more efficient than natural windbreaks or classical nets to reduce wind damage in citrus fruit.  相似文献   

Lysosomal stability during phagocytosis of Aspergillus flavus spores by alveolar macrophages of cortisone-treated mice   总被引：8，自引：0，他引：8  

L Merkow  M Pardo  S M Epstein  E Verney  H Sidransky 《Science (New York, N.Y.)》1968,160(823):79-81

Control mice and those treated with cortisone were exposed to aerosols of viable spores of Aspergillus flavus. Fifteen to 20 minutes later, animals were killed, and alveolar macrophages were obtained by tracheobronchial lavage. Electron-microscopic examination of these cells revealed that, whereas the lysosomes of control macrophages showed extensive attraction and fusion with the phagocytic membranes surrounding spores, the lysosomes of macrophages from animals treated with cortisone revealed little, if any, interaction. This diminished lysosomal response in forming phagocytic vacuoles may be important in the subsequent development of hyphal bronchopneumonia which frequently, occurs in cortisonetreated mice exposed to spores of A. flavus.  相似文献   

Energy audit of irrigation networks     

Miguel A. Pardo  Juan Manzano  Enrique Cabrera  Jorge García-Serra 《Biosystems Engineering》2013,115(1):89-101

  相似文献   

A proposal to define vulnerability of cetacean areas to human development: variables and analysis procedures applied to the Gulf of California     

Priscilla Cubero‐Pardo  Carl Donovan  Jorge Urbán‐Ramírez 《水产资源保护:海洋与淡水生态系统》2011,21(5):433-447

Validation of molecular markers for pathogen resistance in potato     

Raquel Lopez‐Pardo  Leire Barandalla  Enrique Ritter  Jose I. Ruiz de Galarreta 《Plant Breeding》2013,132(3):246-251

DNA markers have a large potential to improve efficiency and precision of conventional plant breeding programmes based on marker‐assisted selection (MAS). In our study, we have evaluated the predictive abilities of the SCAR marker RYSC3 and the CAPS marker GP122₅₆₄ with regard to the PVY resistance genes Ry_adg and Ry_sto, respectively, and of marker TG689 linked to H1 conferring resistance to Globodera rostochiensis and marker HC associated with high levels of G. pallida resistance. The evaluations were made in 28 cultivars and accessions and in 219 progeny genotypes descending from ten different crosses. We observed in all evaluated cultivars and accessions the expected marker patterns according to their phenotypic classification into resistant and susceptible genotypes. However, in part considerable discrepancies were observed when analysing progeny of controlled crosses involving these resistance sources, particularly with respect to H1. Based on these results, practical aspects for the efficient implementation of marker‐assisted selection are discussed, which consider the genetic origin of the material, costs aspects and methodology applied.  相似文献