Potential impacts of seasonal and altitudinal changes on enzymatic peat decomposition in the High Andean Paramo region of Ecuador.

The Andean Paramo is a vast ecosystem, characterized by distinct vegetational zones at several altitudinal levels with huge water storage and carbon fixation capacity within its peat-like andosols, due to a slow decomposition rate of organic matter. These characteristics become mutually related as enzymatic activities increase with temperature and are associated with oxygen penetration, restricting the activity of many hydrolytic enzymes according to the enzyme Latch Theory. This study describes the changing activity of sulfatase (Sulf), phosphatase (Phos), n-acetyl-glucosaminidase (N-Ac), cellobiohydrolase (Cellobio), ß-glucosidase (ß-Glu), and peroxidase (POX) on an altitudinal scale from 3600 to 4200 m, in rainy and dry seasons at 10 and 30 cm sampling depth, related to physical and chemical soil characteristics, like metals and organic elements. Linear fixed-effect models were established to analyze these environmental factors to determine distinct decomposition patterns. The data suggests a strong tendency towards decreasing enzyme activities at higher altitudes and in the dry season up to two-fold stronger activation for Sulf, Phos, Cellobio, and ß-Glu. Especially the lowest altitude showed considerably stronger activity of N-Ac, ß-Glu, and POX. Although sampling depth revealed significant differences for all hydrolases but Cellobio, it had minor effects on model outcomes. Further organic rather than physical or metal components of the soil explain the enzyme activity variations. Although the levels of phenols coincided mostly with the soil organic carbon content, there was no direct relation between hydrolases, POX activity, and phenolic substances. The outcome suggests that slight environmental changes with global warming might cause important changes in enzyme activities leading to increased organic matter decomposition at the borderline between the paramo region and downslope ecosystems. Expected extremer dry seasons could cause critical changes as aeration increases peat decomposition leading to a constant liberation of carbon stocks, which puts the paramo region and its ecosystem services in great danger.

Prospection of Psychrotrophic Filamentous Fungi Isolated from the High Andean Paramo Region of Northern Ecuador: Enzymatic Activity and Molecular Identification.

The isolation of filamentous fungal strains from remote habitats with extreme climatic conditions has led to the discovery of a series of enzymes with attractive properties that can be useful in various industrial applications. Among these, cold-adapted enzymes from fungi with psychrotrophic lifestyles are valuable agents in industrial processes aiming towards energy reduction. Out of eight strains isolated from soil of the paramo highlands of Ecuador, three were selected for further experimentation and identified as Cladosporium michoacanense, Cladosporium sp. (cladosporioides complex), and Didymella sp., this last being reported for the first time in this area. The secretion of seven enzymes, namely, endoglucanase, exoglucanase, ß-D-glucosidase, endo-1,4-ß-xylanase, ß-D-xylosidase, acid, and alkaline phosphatases, were analyzed under agitation and static conditions optimized for the growth period and incubation temperature. Cladosporium strains under agitation as well as incubation for 72 h mostly showed the substantial activation for endoglucanase reaching up to 4563 mU/mL and xylanase up to 3036 mU/mL. Meanwhile, other enzymatic levels varied enormously depending on growth and temperature. Didymella sp. showed the most robust activation at 8 °C for endoglucanase, ß-D-glucosidase, and xylanase, indicating an interesting profile for applications such as bioremediation and wastewater treatment processes under cold climatic conditions.

National and subnational coverage and inequalities in reproductive, maternal, newborn, child, and sanitary health interventions in Ecuador: a comparative study between 1994 and 2012.

BACKGROUND: Latin America (LA) has experienced constant economic and political crises that coincide with periods of greater inequality. Between 1996 and 2007 Ecuador went through one of the greatest political and socio-economic crises in Latin America, a product of neo-liberal economic growth strategies. Between 2007 and 2012 it regained political stability, promoted redistributive policies, and initiated greater social spending. To understand the possible influence on the political and economic context, we analyzed the coverage and inequalities in five Reproductive, Maternal, and Child Health (RMNCH) and two water and sanitation interventions using survey data from a broad time window (1994-2012), at a national and subnational level. METHODS: The series cross-sectional study used data from four representative national health surveys (1994, 1999, 2004 and 2012). Coverage of RMNCH and sanitary interventions were stratified by wealth quintiles (as a measure of the socio-economic level), urban-rural residence and the coverage for each province was mapped. Mean difference, Theil index and Variance-weighted least squares regression were calculated to indicate subnational and temporal changes. RESULTS: From 1994 to 2004, Ecuador evidenced large inequalities whose reduction becomes more evident in 2012. Coverage in RMNCH health service-related interventions showed a rather unequal distribution among the socioeconomic status and across provinces in 1994 and 2004, compared to 2012. Sanitary interventions on the contrary, showed the most unequal interventions, and failed to improve or even worsened in several provinces. While there is a temporary improvement also at the subnational level, in 2012 several provinces maintain low levels of coverage. CONCLUSIONS: The remarkable reduction of inequalities in coverage of RMNCH interventions in 2012 clearly coincides with periods of regained political stability, promoted redistributive policies, and greater social spending, different from the former neo-liberal reforms which is consistent with observations made in other Latin American countries. Territorial heterogeneity and great inequalities specially related with sanitation interventions persists. It is necessary to obtain high quality information with sharper geographic desegregation that allows to identify and understand local changes over time. This would help to prioritize intervention strategies, introduce multisectoral policies and investments that support local governments.

Differentiated NSC-34 motoneuron-like cells as experimental model for cholinergic neurodegeneration.

Alpha-motoneurons appear to be exceedingly affected in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). Morphological and physiological degeneration of this neuronal phenotype is typically characterized by a marked decrease of neuronal markers and by alterations of cholinergic metabolism such as reduced choline acetyltransferase (ChAT) expression. The motoneuron-like cell line NSC-34 is a hybrid cell line produced by fusion of neuroblastoma with mouse motoneuron-enriched primary spinal cord cells. In order to further establish this cell line as a valid model system to investigate cholinergic neurodegeneration, NSC-34 cells were differentiated by serum deprivation and additional treatment with all-trans retinoic acid (atRA). Cell maturation was characterized by neurite outgrowth and increased expression of neuronal and cholinergic markers, including MAP2, GAP-43 and ChAT. Subsequently, we used differentiated NSC-34 cells to study early degenerative responses following exposure to various neurotoxins (H2O2, TNF-α, and glutamate). Susceptibility to toxin-induced cell death was determined by means of morphological changes, expression of neuronal marker proteins, and the ratio of pro-(Bax) to anti-(Bcl-2) apoptotic proteins. NSC-34 cells respond to low doses of neurotoxins with increased cell death of remaining undifferentiated cells with no obvious adverse effects on differentiated cells. Thus, the different vulnerability of differentiated and undifferentiated NSC-34 cells to neurotoxins is a key characteristic of NSC-34 cells and has to be considered in neurotoxic studies. Nonetheless, application of atRA induced differentiation of NSC-34 cells and provides a suitable model to investigate molecular events linked to neurodegeneration of differentiated neurons.