A Petunia homeodomain-leucine zipper protein, PhHD-Zip, plays an important role in flower senescence.

Flower senescence is initiated by developmental and environmental signals, and regulated by gene transcription. A homeodomain-leucine zipper transcription factor, PhHD-Zip, is up-regulated during petunia flower senescence. Virus-induced gene silencing of PhHD-Zip extended flower life by 20% both in unpollinated and pollinated flowers. Silencing PhHD-Zip also dramatically reduced ethylene production and the abundance of transcripts of genes involved in ethylene (ACS, ACO), and ABA (NCED) biosynthesis. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was also dramatically reduced in the silenced flowers. Over-expression of PhHD-Zip accelerated petunia flower senescence. Furthermore, PhHD-Zip transcript abundance in petunia flowers was increased by application of hormones (ethylene, ABA) and abiotic stresses (dehydration, NaCl and cold). Our results suggest that PhHD-Zip plays an important role in regulating petunia flower senescence

Landscapes to Learnscapes: Exploring Schoolyard-based Education

This thesis explores schoolyard-based education as a viable and necessary method for rectifying the shortcomings within the American public school system and the Nature-deficit Disorder epidemic. We argue that schoolyard-based education should be fully integrated into the school system, not in the sole form of popularized school gardens, but as a standard teaching method. We show this using extensive research and a case study of three elementary schools in Claremont, California

Rhynchomeliola Speg., un viejo género nuevo para Argentina

Al estudiar los micromicetes asociados a plantas nativas de los bosques andinopatagónicos, se coleccionaron ejemplares de dos especies de Rhynchomeliola Speg.: R. lomatiae S. Lee & Joanne E. Taylor creciendo sobre hojas de Lomatia ferruginea (Proteaceae), y R. usteriana (Speg.) Arx & Müller asociado a corteza de Nothofagus pumilio (Nothofagaceae). Rhynchomeliola es un género de posición incierta que reúne pocas especies, mayormente folícolas y tropicales, caracterizadas por poseer ascomas periteciales no estromáticos, de cuellos largos y delgados. En Sudamérica este género solo se conocía en Brasil, siendo esta la primera cita del mismo para Argentina. Asimismo este es el primer hallazgo de R. lomatiae desde su descripción original de material herborizado de Lomatia polymorpha proveniente de Australia. El descubrimiento de R. usteriana sobre corteza representa la primera descripción de una especie del género sobre un sustrato lignificado, y sustentaría el rechazo del hábito como carácter válido para distinguir Rhynchomeliola respecto del género afín Rhynchostoma P. Karst. Se proveen descripciones e ilustraciones completas de las especies encontradas, así como de los tipos de las especies descriptas por Spegazzini.During a survey of the micromycetes growing on native plants from the Patagonian Andean forests, two species of Rhynchomeliola Speg. were found: R. lomatiae S. Lee & Joanne E. Taylor growing on leaves of Lomatia ferruginea (Proteaceae), and R. usteriana (Speg.) Arx & Müller growing on bark of Nothofagus pumilio (Nothofagaceae). Rhynchomeliola is a small genus of long-necked, non stromatic, perithecial fungi which comprises nine species that are mostly tropical and foliicolous. In South America this genus was known only from Brazil. Rhynchomeliola lomatiae is recorded for the first time since its original description from herbarium material of Lomatia polymorpha in Australia. The finding of R. usteriana growing on bark is the first record of a Rhynchomeliola species on a lignified substrate and supports the rejection of the habit as a useful character to distinguish the genus from the morphologically akin Rhynchostoma P. Karst. Full descriptions and illustrations of the recorded species are provided along with those of the type materials of the species described by Spegazzini.Fil: Bianchinotti, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Sanchez, Romina Magali. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Rajchenberg, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentin

Contributo alla flora del Parco Nazionale della Majella

Viene presentato un ulteriore contributo alla ricca flora del Parco Nazionale della Majella. In particolare, 15 nuove entità vengono segnalate per la prima volta ed una viene confermata nell’area protetta. Per altre entità, rare sul territorio regionale, vengono segnalate nuove stazioni all’interno del Parco. Il contributo conferma come la ricerca sul campo sia di fondamentale importanza per approfondire le conoscenze sul patrimonio naturale, anche nel caso di territori abbastanza ben conosciuti come quello del Parco Nazionale della Majella.A further contribution to the rich flora of the Majella National Park is presented. In particular, 15 entities are reported for the first time and one is confirmed in the protected area. New localities are also indicated, inside the Park, for some plant species that are very rare in the Abruzzo region. It is confirmed that field research is of crucial importance in expanding our knowledge of the natural heritage, even in a fairly well known territory as that of the Majella National Park

Ecological conditions of the nordpatagonic native forest in an Andean basin of southern Chile (43°30' - 44°00'S)

Analizamos en una cuenca andino-patagónica de Chile meridional, la intensa degradación de los ecosistemas forestales constatada en la cuenca superior del río Palena (43° 30' - 44° 00' S). Extensivos incendios producidos en la montaña andina, entre los años 1930 a 1955 iniciaron la alteración y retrocesodel bosque nativo con predominio de Nothofagus. La erosión y la activa dinámica geomorfológica de la cordillera (derrumbes, deslizamientos, rodados), ha contribuido también de modo importante en la pérdida de los árboles. La quema del bosque con el objeto de obtener espacios para praderas junto con laextracción de leña, constituyen el factor antrópico constante en el desarrollo de este proceso. Actualmente se observa, sólo en algunos sectores, una lenta y dificultosa regeneración de especies leñosas, la que va acompañada por la intrusión de arbustos exóticos.We analyzed in a Chilean Andean southern basin, the intensive degradation of the forest ecosystems in the upper basin of the Palena river (43° 30' -44°00'S) Extensive fire forest produced dunng 1930 to 1955 in the Andean mountain, generated the impact of the native forest wich is predominantly Nothofagus.The erosion and the intense geomorphic dynamic of the mountain (landslide, landslipping) have also contributed to the destruction of the tres. The controlled fire forest in order to obtain room for prairies along with the wood log extraction, are the constant anthropogenic factor in the development of this process. In the days it isrecognized, in just few places, a slow and difficult regeneration of wood species,wich is accompany with exotic bushes

Systematic list of Chilean Curculionoidea species (Insecta: Coleoptera), with its synonymy

Se entrega una lista sistemática actualizada de las especies de Curculionoidea registradas como presentes en Chile, incluyendo su sinonimia. Para cada una de las especies se agrega su distribución geográfica a nivel mundial por países y en algunos casos se agregan datos biológicos, nuevos o ya conocidos. En relación a su distribución en Chile, se indica su presencia a nivel de las actuales provincias administrativas. En el caso de especies compartidas con Argentina, se señala también su distribución en ese país por provincias o territorio. Se registra por primera vez la presencia en Chile del Nemonychidae Rhynchitomacer nigritus Kuschel, 1954 y de los Curculionidae Cylydrorhinus marinus (Burmeister, 1879) y Stenopelmus brunneus (Hustache, 1939). Se citan 171 géneros con 525 especies.An updated systematic list of the species of Curculionoidea recorded as present in Chile, with their synonymy, is provided. For each species, the worldwide distribution by countries is given, and in some cases, new or already known biological information is also presented. Regarding their distribution in Chile, the presence in the current administrative provinces is given. For those species shared with Argentina, their distribution in that country by provinces or territory is also indicated. First records in Chile are reported for the Nemonychidae Rhynchitomacer nigritus Kuschel, 1954 and for the Curculionidae Cylydrorhinus marinus (Burmeister, 1879) and Stenopelmus brunneus (Hustache, 1939). 171 genera and 525 species are cited.Fil: Elgueta, Mario. Museo Nacional de Historia Natural; ChileFil: Marvaldi, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Quality of mortality statistics in Chile, 1997-2003

Nunez, M.L. Departamento de Salud Pública, Facultad de Ciencias de la Salud, Universidad de Talca. Icaza, M.G.Instituto de Matemática y Física, Universidad de Talca.Death certification is the basis for the study of mortality patterns and the identification of leading causes of death. These data are used for planning health policies and prevention programs. Aim: To evaluate the quality of mortality statistics in Chile from 1997 and 2003. Material and methods: Mortality data from 1997 to 2003 available at the Chilean Ministry of Health was used. Quality of information was evaluated using the percentage of certifications done by physicians and ill-defined causes of death according to rural or urban residence, medical services, age and gender. Results: Death certification done by physicians increased from 97.6% to 99.0% in the studied period. The greatest increase was observed in rural areas, from 89.9% to 94,8%. There was a steady reduction in the percentage of ill-defined causes of deaths, from 4.7% in 1997 to 2.8% in 2003. The percentage of ill-defined causes had a great variation among the different medical services. The variation went from 1.5% in Magallanes to 13.7% in Araucania Sur. There was an inverse linear correlation between death certification by physicians and ill-defined conditions. Conclusions: Quality of Chilean mortality statistics has improved over time. Nevertheless, there is still space for enhancement for the appropriate use of this information

Un saber geográfico en acción: Hans Steffen y el litigio patagónico 1892-1902

This article examines the work of Hans Steffen as geographer of the government of Chile between 1892 and 1902 in the litigation against Argentina for the delimitation of Patagonia. This conflict confronted two scientific criteria to address the political boundaries: the division of water, or "divortium aquarum" defended by Chile and the notion of the highest peaks of the range, or "main chain", supported by Argentina. Here we analyze how Steffen prepared the Chilean position, from his explorations and studies, and for the Court of Arbitration in London, where both views were defended

Hahb-4, a homeobox-leucine zipper gene potentially involved in abscisic acid-dependent responses to water stress in sunflower

The nucleotide sequence data reported will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession numbers AF339748 and AF339749.Homeodomain-leucine zipper proteins constitute a family of transcription factors found only in plants. We have characterized a full-length cDNA encoding the sunflower homeobox-leucine zipper protein Hahb-4 (Helianthus annuus homeo box-4). The complete cDNA is 674 base pairs long and contains an open reading frame of 177 amino acids that belongs to the Hd-Zip I subfamily. Northern blot and RNAse A protection analysis show that the expression of Hahb-4 is rapidly, strongly and reversibly induced by water deficit in whole seedlings, roots, stems and leaves. A similar fast induction of Hahb-4 expression is observed when seedlings are subjected to a treatment with the hormone abscisic acid (ABA). Nuclei prepared from seedlings treated with ABA or subjected to water stress show a significant increase of protein(s) that specifically bind the sequence 5′-CAAT(A/T)ATTG-3′, recognized in vitro by Hahb-4, suggesting that an active protein is synthesized in response to these treatments. The promoter region of the Hahb-4 gene contains sequences that fit the consensus for a G-box present in some ABA responsive elements (ABREs). We propose that Hahb-4 may function in signalling cascade(s) that control(s) a subset of the ABAmediated responses of sunflower to water stress.This work was supported by grants from CONICET, ANPCyT, Fundación Antorchas (Argentina) and Universidad Nacional del Litoral. R.L.C. and D.H.G. are members of CONICET; G.M.G. is a fellow of the same Institution. The laboratory work of J.J. and C.A. was also supported by grants BIO99-794 (from the Spanish Comisión Interministerial de Ciencia y Tecnología) and CVI 148 (from Plan Andaluz de Investigación).Peer reviewe

Trapping and Characterization of a Reaction Intermediate in Carbapenem Hydrolysis by \u3cem\u3eB. cereus\u3c/em\u3e Metallo-β-lactamase

Metallo-β-lactamases hydrolyze most β-lactam antibiotics. The lack of a successful inhibitor for them is related to the previous failure to characterize a reaction intermediate with a clinically useful substrate. Stopped-flow experiments together with rapid freeze−quench EPR and Raman spectroscopies were used to characterize the reaction of Co(II)−BcII with imipenem. These studies show that Co(II)−BcII is able to hydrolyze imipenem in both the mono- and dinuclear forms. In contrast to the situation met for penicillin, the species that accumulates during turnover is an enzyme−intermediate adduct in which the β-lactam bond has already been cleaved. This intermediate is a metal-bound anionic species with a novel resonant structure that is stabilized by the metal ion at the DCH or Zn2 site. This species has been characterized based on its spectroscopic features. This represents a novel, previously unforeseen intermediate that is related to the chemical nature of carbapenems, as confirmed by the finding of a similar intermediate for meropenem. Since carbapenems are the only substrates cleaved by B1, B2, and B3 lactamases, identification of this intermediate could be exploited as a first step toward the design of transition-state-based inhibitors for all three classes of metallo-β-lactamases