Genetic diversity of potato landraces from northwestern Argentina assessed with simple sequence repeats (SSRs)     

Verónica Nilda Ispizúa  Irma Rosana Guma  Sergio Feingold  Andrea Martina Clausen 《Genetic Resources and Crop Evolution》2007,54(8):1833-1848

Andean potato varieties are cultivated in the northwest of Argentina and constitute the most important staple food for the local farmers. The genetic diversity of 155 accessions conserved at the Genebank of Balcarce (INTA) was tested using four microsatellites. Three commercial potato varieties of Tuberosum group and one accession of Curtilobum group were used as outgroups. The presence of bands was scored for each microsatellite and for each accession and the data were analysed by principal coordinate analysis. The polymorphism information content was obtained for each molecular marker from banding patterns. Analysis of molecular variance was carried out with a variable number of accessions for each landrace, from different departments and sites within departments. More than one genotype was detected in the majority of the potato landraces. Some accessions within each landrace did not differentiate. AMOVA revealed that most of the genetic variation occurred among sites within departments and among local varieties. These findings are discussed considering the agricultural practices carried out in the Andean farming system.  相似文献   

Development of the Regional Policy Process for Air Pollution in South Asia,Southern Africa and Latin America     

Hicks  W. Kevin  Kuylenstierna  Johan C.I.  Mathur  Vikrom  Mazzucchelli  Sergio  Burijson  Viviana  Shrestha  Surendra  Iyngararasan  Mylvakanam  Simukanga  Stephen  Van Tienhoven  A. Mieke 《Water, air, and soil pollution》2001,130(1-4):211-216

Projections indicate that large increases in emissions may occur in developing countries during the next twenty to fifty years if current development patterns persist. This paper describes the development of co-operation regarding air pollution issues in three sub-regions of three continents. Experiences gained through activities within a programme on Regional Air Pollution in Developing Countries are used to illustrate progress. The sub-regional process in South Asia developed through a series of meetings that led to the Malé Declaration. In southern Africa a policy dialogue led to the Harare Resolution targeted towards progress in the SADC region. A policy dialogue in Buenos Aires concentrated on issues related to regional harmonisation of legal frameworks in the Mercosur region. In all regions the link between scientific information required to support decision making has been emphasised. The sub-regional policy processes are analysed in relation to availability of required scientific information and compared to the process that led to protocol development in Europe.  相似文献   

Heavy Metal Contamination in Sediments of Lake Nahuel Huapi,Nahuel Huapi National Park,Northern Patagonia,Argentina     

Ribeiro Guevara  Sergio  Massaferro  Julieta  Villarosa  Gustavo  Arribére  María  Rizzo  Andrea 《Water, air, and soil pollution》2002,137(1-4):21-44

Trace metals (Sb, As, Br, Cs, Co, Cr, Ag and Hg), rare earth elements (Ce, Eu, La, Lu, Sm, Tb and Yb), and Sc. were analysed in suspended load and in two sediment cores from Lake Nahuel Huapi, Nahuel Huapi National Park, Patagonia, Argentina, by using Instrumental Neutron Activation Analysis. The core activity profiles of ²¹⁰Pb and ¹³⁷Cs were measured to estimate the age of the sediments. Silver was enriched in the upper layers of both cores, and correlated with the strong growthof the population of Bariloche City in the last 50 yr. Concentrations are higher in the core sampled near Bariloche, andindicate some transport in the water body. Silver concentrationsmeasured in the suspended load were 4.58±0.36 and 3.46±0.40 μg g^-1 in the southern margin of the lake, near San Carlos de Bariloche City, whereas in the northern margin the concentrations were 1.68±0.18 and 1.88±0.23 μg g^-1. Concentration ratio for silver in suspended load and upper core layers were equal in both sampling points. These facts suggest that Ag contents correspond to inputs associated with human activities. Bromine concentrations show a strong increase abovebase line values, similar to silver. In contrast, caesium, chromium, and cobalt concentrations do not differ from base linevalues. The metalloids antimony and arsenic show little variationwith regard to base line concentration. Noticeable, the mercurycontents found in the suspended load.  相似文献   

Correction of ADA-SCID by stem cell gene therapy combined with nonmyeloablative conditioning     

Aiuti A  Slavin S  Aker M  Ficara F  Deola S  Mortellaro A  Morecki S  Andolfi G  Tabucchi A  Carlucci F  Marinello E  Cattaneo F  Vai S  Servida P  Miniero R  Roncarolo MG  Bordignon C 《Science (New York, N.Y.)》2002,296(5577):2410-2413

Hematopoietic stem cell (HSC) gene therapy for adenosine deaminase (ADA)-deficient severe combined immunodeficiency (SCID) has shown limited clinical efficacy because of the small proportion of engrafted genetically corrected HSCs. We describe an improved protocol for gene transfer into HSCs associated with nonmyeloablative conditioning. This protocol was used in two patients for whom enzyme replacement therapy was not available, which allowed the effect of gene therapy alone to be evaluated. Sustained engraftment of engineered HSCs with differentiation into multiple lineages resulted in increased lymphocyte counts, improved immune functions (including antigen-specific responses), and lower toxic metabolites. Both patients are currently at home and clinically well, with normal growth and development. These results indicate the safety and efficacy of HSC gene therapy combined with nonmyeloablative conditioning for the treatment of SCID.  相似文献   

Protecting invaders for profit     

Lambertucci SA  Speziale KL 《Science (New York, N.Y.)》2011,332(6025):35

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Cell biology. A one-sided signal     

Fairn GD  Grinstein S 《Science (New York, N.Y.)》2008,320(5875):458-460

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Phylogeny of the SARS coronavirus     

Eickmann M  Becker S  Klenk HD  Doerr HW  Stadler K  Censini S  Guidotti S  Masignani V  Scarselli M  Mora M  Donati C  Han JH  Song HC  Abrignani S  Covacci A  Rappuoli R 《Science (New York, N.Y.)》2003,302(5650):1504-1505

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Immunology. The tangled webs that neutrophils weave     

Lee WL  Grinstein S 《Science (New York, N.Y.)》2004,303(5663):1477-1478

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Acetylcholine-synthesizing T cells relay neural signals in a vagus nerve circuit     

Rosas-Ballina M  Olofsson PS  Ochani M  Valdés-Ferrer SI  Levine YA  Reardon C  Tusche MW  Pavlov VA  Andersson U  Chavan S  Mak TW  Tracey KJ 《Science (New York, N.Y.)》2011,334(6052):98-101

Neural circuits regulate cytokine production to prevent potentially damaging inflammation. A prototypical vagus nerve circuit, the inflammatory reflex, inhibits tumor necrosis factor-α production in spleen by a mechanism requiring acetylcholine signaling through the α7 nicotinic acetylcholine receptor expressed on cytokine-producing macrophages. Nerve fibers in spleen lack the enzymatic machinery necessary for acetylcholine production; therefore, how does this neural circuit terminate in cholinergic signaling? We identified an acetylcholine-producing, memory phenotype T cell population in mice that is integral to the inflammatory reflex. These acetylcholine-producing T cells are required for inhibition of cytokine production by vagus nerve stimulation. Thus, action potentials originating in the vagus nerve regulate T cells, which in turn produce the neurotransmitter, acetylcholine, required to control innate immune responses.  相似文献   

Looking back to see ahead: Farmer lessons and recommendations after 15 years of innovation and leadership in Güinope, Honduras     

Stephen Sherwood  Sergio Larrea 《Agriculture and Human Values》2001,18(2):195-208

Güinope, Honduras was the site of a highly acclaimed people-centered development project in the 1980s. The ACORDE/Ministry of Natural Resource/World Neighbors Integrated Development Program (IDP) was unique for its time, since rather than relying on technology transfer, it promoted innovation skills for local generation of responses to needs. Furthermore, it was one of the first efforts in Latin America to employ villagers as principal agents of change. Fifteen years after the inception of the IDP and ten years after its completion, the authors interviewed farmers in their fields and held a series of participatory workshops over eighteen months with ten outstanding farmers who had become project leaders. The leaders identified influential factors behind their involvement and produced recommendations for rural development interventions. Further, a generalized concept map typifying ideal characteristics for farmer promoters was constructed. Recommendations for development agencies centered on project design and implementation, demanding a methodology for strengthening local innovative capacities, participation, and control over resources. Ultimately, the leaders downplayed the role of technologies in rural development and called for special attention to enabling communities to confront external pressures, in particular recent government ``modernization' policies, that they felt threatened community livelihood. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献