The failure of Viking Lander thermal volatilization (TV) (without or with thermal degradation)-gas chromatography (GC)-MS experiments to detect organics suggests chemical rather than biological interpretations for the reactivity of the martian soil. Here, we report that TV-GC-MS may be blind to low levels of organics on astrobiology ͉ detection of organics ͉ search for martian life ͉ extreme environments ͉ deserts

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A paleoclimate reconstruction for the Holocene based upon variations of δ18O in a U–Th dated stalagmite from southwestern Mexico is presented. Our results indicate that the arrival of moisture to the area has been strongly linked to the input of glacial meltwaters into the North Atlantic throughout the Holocene. The record also suggests a complex interplay between Caribbean and Pacific moisture sources, modulated by the North Atlantic SST and the position of the ITCZ, where Pacific moisture becomes increasingly more influential through ENSO since ~ 4.3 ka. The interruption of stalagmite growth during the largest climatic anomalies of the Holocene (10.3 and 8.2 ka) is evidenced by the presence of hiatuses, which suggest a severe disruption in the arrival of moisture to the area. The δ18O record presented here has important implications for understanding the evolution of the North American Monsoon and climate in southwestern Mexico, as it represents one of the most detailed archives of climate variability for the area spanning most of the Holocene.

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On a global basis, nearly 42% of tropical land area is classified as tropical deciduous forest (TDF) (Murphy and Lugo 1986). Currently, this ecosystem has very high deforestation rates; and its conversion to cattle pasture may result in losses of soil organic matter, decreases in soil fertility, and increases in CO flux to the atmosphere. The soil organic matter turnover rate in a TDF after pasture conversion was estimated in Mexico by determining natural abundances ofC. Changes in these values would be induced by vegetation changes from the C (forest) to the C (pasture) photosynthetic pathway. The rate of loss of remnant forest-soil organic matter (fSOM) was 2.9 t ha year in 7-year-old pasture and decreased to 0.66 t ha year by year 11. For up to 3 years, net fSOM level increased in pastures; this increment can be attributed to decomposition of remnant forest roots. The sand-associated SOM fraction was the most and the silt-associated fraction the least depleted. TDF conversion to pasture results in extremely high rates of loss of remnant fSOM that are higher than any reported for any tropical forest.

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Wellness is a term often used to talk about optimal health as "dynamic balance of physical, emotional, social, spiritual, and intellectual health." While healthcare is a term about care offered to patients for improving their health. We use both terms, as well as the Business Model Canvas (BMC) methodology, to design a digital ecosystem model for healthcare and wellness called DE4HW; the model considers economic, technological, and legal asymmetries, which are present on e-services beyond geographical regions. BMC methodology was embedded into the global project strategy called: IBOT (Initiate, Build, Operate and Transfer); it is a methodology to establish a functional, integrated national telemedicine network and virtual education network; of which we took its phases rationale. The results in this work illustrate the design of DE4HW model, into the first phase of IBOT, enriched with the BMC, which enables us to define actors, their interactions, rules and protocols, in order to build DE4HW, while IBOT strategy manages the project goal, up to the transfer phase, where an integral service platform of healthcare and wellness is turned over to stakeholders.