Chemical Modification of Starch with Synthetic

An alternative for solving the environmental pollution problems generated by conventional plastics, it is the chemical modifications graft-type of the starch with synthetic polymers of post-consumer and in situ polymerizations on the starch granules. The starch modified by this methodology allows to counteract the disadvantages of both polymers such as the little or no biodegradability of the synthetic polymer and the poor mechanical properties of the starch. In the present study, a review on the chemical modification of starch with synthetic polymers by grafting is carried out. Factors affecting the copolymerization reactions of starch-g-synthetic polymer were analyzed, for example, their chemical nature, solubility, size and length of polymer chains, temperature, catalyst and starch/amylose content, as well as their characterization chemistry and the potentials applications of this copolymer

Diversity of Copestylum Macquart, 1846 (Diptera, Syrphidae) associated to decaying cacti (Cactaceae Juss, 1789) in two Biosphere Reserves from central Mexico

El conocimiento de la biodiversidad de los sírfidos (Diptera: Syrphidae) en las zonas semiáridas de México, es muy limitado, sobre todo, al relacionado con las cactáceas en descomposición. Este estudio aporta un inventario faunístico de los sírfidos del género Copestylum asociados a los tejidos en descomposición de los cactus de matorrales crasicaules en dos Reservas de la Biosfera, “Barranca de Metztitlán” (RBBM) y “Tehuacán-Cuicatlán” (RBTC), ambas situadas en el centro de México. Se analiza la diversidad y composición de especies de sírfidos en ambas reservas y se documenta la especie de cactus a la que se asocian las larvas de estos dípteros durante la época de lluvias. El método de recolecta fue mediante búsqueda directa de estados inmaduros que se desarrollan en tejidos de cactáceas en descomposición. Se obtuvieron 137 ejemplares de sírfidos pertenecientes a 10 especies entre las dos reservas estudiadas. Los resultados indican que no existen diferencias significativas en la riqueza de especies entre ambas reservas, pero sí hay diferencia al comparar la diversidad de orden q2. En la RBBM, la especie dominante fue Copestylum latum, mientras que Copestylum posticum fue la especie dominante en la RBTC. La especie de cactus determina la segregación de sírfidos en cada reserva. En la RBBM, las especies de sírfidos se asociaron a las especies de cactus Isolatocereus dumortieri y Myrtillocactus geometrizans, mientras que, en la RBTC fueron Neobuxbaumia mezcalensis, Pachycereus hollianus y Myrtillocactus geometrizans.Biodiversity knowledge of syrphids (Diptera: Syrphidae) from the semiarid environments of Mexico is still limited; particularly, those associated to the decaying cactus. In this study, we provide an inventory of the syrphid species from two Biosphere Reserves in the semiarid zones of central Mexico. We compare the diversity and species composition of syrphids through both Biosphere Reserves and we documented the host cactus species of syrphids during the rainy season. Larvae were sampled by hand searching on decayed cacti tissues. We recorded a total of 137 individuals of syrphids and 10 species between the two studied Biosphere Reserves. Our results revealed that there are not significant differences in species richness between RBBM and RBTC but there were significant differences in species diversity of order q2. We found that Copestylum latum was the dominant syrphid at RBBM whereas Copestylum posticum was dominant across the RBTC. The cactus species is presumably determining the species segregation of syrphids. In the RBBM, syrphid were associated to the cacti Isolatocereus dumortieri and Myrtillocactus geometrizans; meanwhile, in the RBTC syrphids were associated to Neobuxbaumia mezcalensis, Pachycereus hollianus and Myrtillocactus geometrizans

Sceloporus smithi Hartweg and Oliver, 1937 (Squamata: Phrynosomatidae): distributional range extension and a new elevation record from Oaxaca, México

A male Sceloporus smithi was collected at Hierve El Agua, in the Municipality of San Lorenzo Albarradas, Oaxaca, México. This record extends the known distribution of the species by approximately 25 km N from the closest acknowledged locality and also represents a new upward elevational record. Even though the elevation at this site is almost 700 m higher than for previously documented localities, the subhumid forest and igneous rock association is similar to other inhabited localities at lower elevations

Primer registro de <i>Sceloporus serrifer</i> Cope 1866, (Squamata: Phrynosomatidae) para Quintana Roo, México

Se reporta por primera vez para el estado de Quintana Roo la presencia de la lagartija Sceloporus serrifer. Este hallazgo es importante ya que extiende el rango de distribución a 217 km de la localidad más cercana y amplia el rango de distribución de la especie dentro de la península de Yucatán, además, aumenta el número de especies de saurios presentes en este estado.Asociación Herpetológica Argentina (AHA

Primer registro de <i>Sceloporus serrifer</i> Cope 1866, (Squamata: Phrynosomatidae) para Quintana Roo, México

Se reporta por primera vez para el estado de Quintana Roo la presencia de la lagartija Sceloporus serrifer. Este hallazgo es importante ya que extiende el rango de distribución a 217 km de la localidad más cercana y amplia el rango de distribución de la especie dentro de la península de Yucatán, además, aumenta el número de especies de saurios presentes en este estado.Asociación Herpetológica Argentina (AHA

Primer registro de <i>Sceloporus serrifer</i> Cope 1866, (Squamata: Phrynosomatidae) para Quintana Roo, México

Se reporta por primera vez para el estado de Quintana Roo la presencia de la lagartija Sceloporus serrifer. Este hallazgo es importante ya que extiende el rango de distribución a 217 km de la localidad más cercana y amplia el rango de distribución de la especie dentro de la península de Yucatán, además, aumenta el número de especies de saurios presentes en este estado.Asociación Herpetológica Argentina (AHA

Effects of traditional agroecosystems and grazing areas on amphibian diversity in a region of central Mexico

Habitat loss or degradation due to land cover change is regarded as one of the main drivers of amphibian decline; therefore, it is imperative to assess the effects of land-cover change on this group of vertebrates. In this study, we analyze changes in alpha and beta diversity of amphibian communities found in five land-cover types: mountain cloud forest, tropical evergreen forest, shade coffee, milpa huasteca, and grazing areas; six samples sites were established for each land-cover type, separated at least one km away. The study was conducted in the northwest part of the state of Hidalgo, in a transition zone between the Sierra Madre Oriental and the Gulf of Mexico, which is a region rich in amphibian species. The results indicate that alpha diversity decreases with loss of canopy cover, this being high in mountain cloud forest, tropical evergreen forest, and Shade coffee, and low in milpa huasteca and grazing areas. The land-cover type with the highest species evenness was found in milpa huasteca and the lowest in. The highest beta diversity was observed among tropical evergreen forest and grazing areas. Mountain cloud forest contains both exclusive species and the highest number of species currently regarded as threatened by national and international conservation assessment systems. In order to preserve amphibian diversity in the study area it is vital to protect the last remnants of native vegetation, especially mountain cloud forest, but also including Shade coffee, since the latter habitat harbors amphibian diversity similar to that found in native forests. Finally, implementation of policies that both reduce Grazing areas and increase their productivity is also necessary, since these highly modified areas turn out to be the ones that affect amphibian diversity the most

Xenosaurus newmanorum Taylor, 1949 (Squamata: Xenosauridae): Occurrence in the state of Hidalgo, Mexico

Herein we report 22 individuals of Xenosaurus newmanorum representing a new state record for Hidalgo, Mexico from the Municipality of Pisaflores. Previously, this species was known only from the Municipality of Xilitla in San Luis Potosí. These new records extend the distribution of this species 13.6 km south of its previously known occurrence. We also compare total body and tail lengths for the lizards in addition to cloacal temperatures and several measurements associated with microhabitat characteristics, which are equivalent at all three sites. That microhabitat congruence suggests that its preservation is critical for protecting X. newmanorum from population decline

Preclinical Test of Dacomitinib, an Irreversible EGFR Inhibitor, Confirms Its Effectiveness for Glioblastoma.

Glioblastomas (GBM) are devastating tumors in which there has been little clinical improvement in the last decades. New molecularly directed therapies are under development. EGFR is one of the most promising targets, as this receptor is mutated and/or overexpressed in nearly half of the GBMs. However, the results obtained with first-generation tyrosine-kinase inhibitors have been disappointing with no clear predictive markers of tumor response. Here, we have tested the antitumoral efficacy of a second-generation inhibitor, dacomitinib (PF299804, Pfizer), that binds in an irreversible way to the receptor. Our results confirm that dacomitinib has an effect on cell viability, self-renewal, and proliferation in EGFR-amplified ± EGFRvIII GBM cells. Moreover, systemic administration of dacomitinib strongly impaired the in vivo tumor growth rate of these EGFR-amplified cell lines, with a decrease in the expression of stem cell-related markers. However, continuous administration of the compound was required to maintain the antitumor effect. The data presented here confirm that dacomitinib clearly affects receptor signaling in vivo and that its strong antitumoral effect is independent of the presence of mutant receptor isoforms although it could be affected by the PTEN status (as it is less effective in a PTEN-deleted GBM line). Dacomitinib is being tested in second line for EGFR-amplified GBMs. We hope that our results could help to select retrospectively molecular determinants of this response and to implement future trials with dacomitinib (alone or in combination with other inhibitors) in newly diagnosed GBMs.This work was supported by grants from the Fundación Mutua-madrileña (FMM2011/89) to J.M. Sepúlveda and from Ministerio de Economía y Competitividad, Fondo de Investigación Sanitaria (FIS): PI12/00775 to P. Sánchez-Gómez and PI13/01258 to A. Hernández-Laín, and from Ministerio de Economía y Competitividad, Red Temática de Investigación Cooperativa en Cancer (RTICC) (RD12/0036/0027) to J.M. Sepúlveda, P. Sánchez-Gómez, A. Pérez-Núñez and A. Hernández-Laín.S

Why is the egg retention in oviparous species a step to viviparity?: an example with lizards

Se presenta una revisión sobre las hipótesis ecológicas y fisiológicas en la transición de la oviparidad a la viviparidad usando como grupo modelo a las lagartijas (Squamata). Además, se incluyen ejemplos de especies de lagartijas que prueban la retención de los huevos en el oviducto durante el desarrollo embrionario prolongado en altas latitudes y ambientes templados de montaña. Las hipótesis ecológica y fisiológica indican que el clima frío favorece la retención del huevo por tiempos prolongados y la disminución de glándulas calcáreas, favoreciendo el paso evolutivo a la viviparidad en este grupo de vertebrados. Actualmente, hace falta estudios con especies ovíparas que habitan ambientes templados de altas latitudes (climas fríos) y de ambientes templados de montañas que presentan retención de huevos en estadios avanzados.A review on the ecological and physiological hypotheses in the transition from oviparity to viviparity is presented using lizards (Squamata) as a model group. In addition, examples of lizard species are included that test the retention of eggs in the oviduct during prolonged embryonic development in high latitudes and temperate mountain environments. The ecological and physiological hypotheses indicate that the cold climate favors the retention of the egg for long periods of time and the decrease in calcareous glands, favoring the evolutionary passage to viviparity in this group of vertebrates. To date, studies are needed with oviparous species that inhabit temperate environments at high latitudes (cold climates) and temperate mountain environments that present egg retention in advanced stages