Study of metals in leached soils of a municipal dumpsite in Tampico, Tamaulipas, Mexico: preliminary results

The Zapote dumpsite measures 420000 m 2 and is 28 years old; an estimated 2.5 millions tons of waste have accumulated on the site (household waste, clinical waste, commercial waste). The thickness of the waste is 3 to 9 meters. Since operations began, no control regulations have existed on the residues received. The Zapote dumpsite is located within a salt-marsh between a system of channels and river lagoons of brackish water, located in a tropical sedimentary environment in the urban zone of Tampico, Tamaulipas, Mexico. Recently, the Zapote has been closed and work is presently underway in its rehabilitation since a geo-environmental perspective. The present investigation integrates information of preliminary results of metals (Pb, Ni, Cd, Cu, Mg, Fe and Al) contained in sediments that underlie the Zapote dumpsite. In laboratory research the metals of the sediment were correlated with the metals contained in samples of leachate from the Zapote dumpsite. The concentration of metals Pb, Ni, Cd, Cu, Mg, Fe and Al were analyzed in samples of sediments that underlie the body of the dumpsite in layers of 10 cm, reaching a depth of 1.5 m under the interface waste-soil. The results denote high concentrations of metals in layers that are in contact with waste that decreased until reaching 60 to 80 cm of depth. The proportions of the concentrations of metals studied in the soil are comparable with that leached, until layers of 60 to 80 cm of depth are reached, and are then lost in the deepest layers. The high plastic characteristics of clay layers have stood in the way of metallic contaminants in sub layers of the Zapote dumpsite. The results were correlated with metal concentrations of natural and anthropogenic sediments of the region

High proportion of cactus species threatened with extinction

This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.Consejo Nacional de Ciencia y Tecnologí

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

An unusual new species of Chusquea (Poaceae: Bambusoideae) from Mexico

Chusquea perotensis is described from Volcan Cofre de Perote. Although its spikelets are typical of Chusquea, this species is anomalous in having the internodes hollow with well defined cavities. Based on molecular and morphological data, C. perotensis is classified within Chusquea sect. Swallenochloa, and is considered a sister species of C. bilimekii, also from Mexico. Both species are rare and probably threatened in their fragile montane habitats. Keys, based on vegetative only and vegetative and flowering characters, to the species of Chusquea sect. Swallenochloa in Central America and Mexico are provided

Phoradendron robinsonii

Angiosperm

Phoradendron robinsonii

Angiosperm

Echeveria yalmanantlanensis (Crassulaceae): A new species from Cerro Grande, Sierra de Manantlán, western Mexico

Echeveria yalmanantlanensis, a new species from eastern Sierra de Manantlán, Biosphere Reserve, on the Jalisco-Colima border in western Mexico, is described and illustrated, and a table for comparison of morphologically related taxa is provided. This species belongs to series Valvatae, differing from the other members of the series by its acaulescent habit, shape and color of leaves and bracts, size of scape, bract pattern on scape, size and color of the corolla, habitat, and geographic distribution. There is support for the hypotheses that this species is endemic to the calcareous massif Cerro Grande and is already in danger of extinction. © 2012 The New York Botanical Garden

Echeveria munizii (Crassulaceae) a new species of epiphyte from tropical Volcán de Colima, Mexico

Echeveria yalmanantlanensis, a new species from eastern Sierra de Manantlán, Biosphere Reserve, on the Jalisco-Colima border in western Mexico, is described and illustrated, and a table for comparison of morphologically related taxa is provided. This species belongs to series Valvatae, differing from the other members of the series by its acaulescent habit, shape and color of leaves and bracts, size of scape, bract pattern on scape, size and color of the corolla, habitat, and geographic distribution. There is support for the hypotheses that this species is endemic to the calcareous massif Cerro Grande and is already in danger of extinction. " The New York Botanical Garden.",,,,,,"10.1007/s12228-012-9274-9",,,"http://hdl.handle.net/20.500.12104/40852","http://www.scopus.com/inward/record.url?eid=2-s2.0-84881611243&partnerID=40&md5=7634939a6ea1ceca2b4ba5c8f21f1a82",,,,,,"3",,"Brittonia",,"27

Agave temacapulinensis (Agavaceae), a new ditepalous species from the Los Altos Region, Jalisco, Mexico

Agave temacapulinensis A. Vázquez & Chazaro (Agavaceae) is described and illustrated from Jalisco, Mexico. The new species belongs to Agave L. subg. Agave and is a member of the Ditepalae group, sensu Gentry. It is related to A. wocomahi Gentry in terms of its rosette size, solitary habit in most cases, the smooth texture of the leaves, the red-tipped dimorphic tepals, and the deep floral tube. Agave temacapulinensis differs from A. wocomahi in having light gray, glaucous rosettes (vs. dark green to glaucous green); short acuminate leaves (vs. long acuminate); crenate margins (vs. straight to undulate) with smaller marginal teeth (8-10 mm vs. 10-20 mm); larger panicles (5.5-6.5 m vs. 3-5 m) with more lateral branches (16 to 18 vs. 8 to 15); and smaller seeds (5-6 Zapotitlán 3-4 mm vs. 7 Zapotitlán 4.5-5 mm)