Fire Emissions and Carbon Uptake in Severely Burned Lenga Beech (Nothofagus pumilio) Forests of Patagonia, Argentina

Los incendios forestales son reconocidos como fuentes de emisión de CO2 y otros gases de efecto invernadero (GHG) que, alterando la dinámica del intercambio entre el carbono (C) terrestre y el atmosférico, influencian el clima global. En la región central de la Patagonia Andina Argentina, incendios de características severas han afectado los bosques de lenga (Nothofagus pumilio Poepp. & Endl. Krasser), incrementando de esa manera las emisiones de CO2 a la atmósfera y alterando asimismo sus patrones sucesionales. En este estudio, determinamos las emisiones y el secuestro de C en tres rodales, quemados en 1976 (Lago Guacho), 1983 (La Torta), y 2008 (la Colisión). La estructura forestal, y los compartimientos de biomasa aérea y broza fueron cuantificados en cada rodal quemado y en sus adyacentes sin quemar. El stock de C y de otros GHG (CO2 , CO, CH4 , NO2 , NOx y Ce) emitidos por cada incendio, el CO2 capturado y el C anual incorporado a la biomasa fueron determinados en base a las guías propuestas por el Panel Internacional para el Cambio Climático. El carbono total (biomasa aérea más radical) antes de los incendios fue de 301,8 Mg C ha-1 para La Colisión, 258,13 Mg C ha-1 para La Torta, y 270,7 Mg C ha-1 para Lago Guacho, mientras que las pérdidas de C debido a los incendios fueron de 104,6 Mg C ha-1, 90,7 Mg C ha-1, and 94,7 Mg C ha-1 para cada uno de los sitios, respectivamente. Diferencias en la estructura forestal y en la biomasa de cada sitio previo a los incendios explican los valores de emisión de CO2 y otros GHG observados después de éstos. Al presente, el balance de C es negativo en los tres sitios. Sin ninguna acción de restauración activa y usando las tasas actuales de crecimiento para cada sitio, el tiempo estimado de recuperación del C perdido es de 105,5 años para La Colisión, 94,2 años para La Torta, y 150,2 años para Lago Guacho. Mediante el uso de tasas de captura de C variables (que decrecen a medida que la sucesión avanza), el tiempo de recuperación sería de 182 años para La Colisión, 154 años para La Torta, y 162 para Lago Guacho. El ambiente post-incendio y las condiciones de cada sitio parecen tener una mayor influencia en la recuperación de la vegetación que los efectos primarios del fuego. Tareas de restauración activas aparecen como necesarias para incrementar la tasa de recuperación del C post-fuego y ayudar a re-establecer el paisaje original en bosques de lenga.Forest wildfires are recognized as sources of CO2 and other greenhouse gases (GHG) that, altering the dynamics between terrestrial and atmospheric carbon (C) exchange, influence global climate. In central Andean Patagonia, Argentina, severe wildfires affect temperate lenga beech (Nothofagus pumilio Poepp. & Endl. Krasser) forests, thereby increasing atmospheric CO2 emissions and changing natural succession paths. In this study, we determined fire emissions and C uptake in three lenga beech forests stands burned in 1976 (Lago Guacho site), 1983 (La Torta site), and 2008 (La Colisión site). Forest structure and aboveground biomass and litter compartments in burned and adjacent unburned stands were quantified for each fire. Carbon stocks and GHG (CO2 , CO, CH4 , NO2 , NOx and Ce) released by the fires, CO2 removals, and mean annual C uptake were determined by following the International Panel of Climate Change guidelines. Total (aboveground plus root) C stock before fires was 301.8 Mg C ha-1 for La Colisión, 258.13 Mg C ha-1 for La Torta, and 270.7 Mg C ha-1 for Lago Guacho, while C losses due to the fires were 104.6 Mg C ha-1, 90.7 Mg C ha-1, and 94.7 Mg C ha-1 for the three sites, respectively. Differences in pre-fire forest structures and biomass explained the values observed in CO2 and other GHG emissions after the fires. Currently, the C balance is negative for the three sites. Without any active restoration and using actual growth rates for each site, the estimated C recovery time is 105.5 yr for La Colisión, 94.2 yr for La Torta, and 150.2 yr for Lago Guacho. By using variable rates of C uptake (which decrease as early succession proceeds), this recovery time will take 182 yr for La Colisión, 154 for La Torta, and 162 yr for Lago Guacho. Post-fire environmental and site conditions appeared to have a greater influence in forest recovery than primary fire effects. Active restoration activities may be necessary to increase C recovery rates and help to re-establish former lenga beech forest landscapes.Fil: Bertolin, María Lila. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Urretavizcaya, María Florencia. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Defossé, Guillermo Emilio. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Universidad Nacional de la Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A Peculiar New Pampatheriidae (Mammalia: Xenarthra: Cingulata) from the Pleistocene of Argentina and Comments on Pampatheriidae Diversity.

Pampatheriidae are a group of cingulates native to South American that are known from the middle Miocene to the lower Holocene. Two genera have been recognized between the lower Pleistocene and the lower Holocene: Pampatherium Gervais and Ameghino (Ensenadan, Bonaerian and Lujanian, lower Pleistocene-lower Holocene) and Holmesina Simpson (Blancan, Irvingtonian, upper Pliocene-lower Holocene). They have been mainly differentiated by their osteoderm morphology and cranio-dental characters. These taxa had a wide latitudinal distribution, extending from the southern part of South America (Península Valdés, Argentina) to North America (Florida, USA). In this contribution, we describe a new genus and species of Pampatheriidae for the lower and middle Pleistocene of Buenos Aires Province and for the upper Pleistocene of Santa Fe Province (Argentina).The new taxon is represented by disarticulated osteoderms, one skull element, two thoracic vertebrae and a right femur and patella. It has extremely complex osteoderm ornamentations and particular morphological characters of the cranial element and femur that are not found in any other species of the family. This new taxon, recorded in the lower-middle Pleistocene (Ensenadan Stage/Age) and in the upper Pleistocene-early Holocene (Lujanian Stage/Age), is incorporated to the Pleistocene mammal assemblage of South America. Finally, the Pampatheriidae diversity is greater during the Lujanian Stage/Age than the Ensenadan Stage/Age

Quantification of BSA-loaded chitosan/oligonucleotide nanoparticles using reverse-phase high-performance liquid chromatography

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Therapeutic proteins are administered subcutaneously because of their instability in the gastrointestinal tract. Current research suggests that polymeric-based nanoparticles, microparticles and liposomes are ideal nanocarriers to encapsulate proteins for disease management. In order to develop a successful drug delivery system, it is crucial to determine drug release profile and stability. However, the non-active excipients in polymeric formulations can influence the quantification of proteins in analytical techniques. This study investigated the effect of nine common polymers on quantification of bovine serum albumin (BSA) using RP-HPLC method. The technique offers advantages such as short analytical time, high accuracy and selectivity. In the meantime, the technique can be employed to separate proteins including BSA, insulin and pigment epithelium-derived factor (PEDF). Furthermore, the RP-HPLC method was applied to quantify the drug release pattern of a novel BSA-loaded nanoparticulate formulation in simulated gastric and intestinal fluids. The nanoparticles were formulated by natural polymer (chitosan) and oligonucleotide (Dz13Scr) using complex coacervation. The prepared particles were found to have small size (337.87 nm), low polydispersity index (0.338) and be positively charged (10.23 mV). The in vitro drug release patterns were characterised using the validated RP-HPLC method over 12 h. [Figure not available: see fulltext.]