Diagnosis for ecological intensification of maize-based smallholder farming systems in the Costa Chica, Mexico

Enhanced utilization of ecological processes for food and feed production as part of the notion of ecological intensification starts from location-specific knowledge of production constraints. A diagnostic systems approach which combined social-economic and production ecological methods at farm and field level was developed and applied to diagnose extent and causes of the perceived low productivity of maize-based smallholder systems in two communities of the Costa Chica in South West Mexico. Social-economic and production ecological surveys were applied and complemented with model-based calculations. The results demonstrated that current nutrient management of crops has promoted nutrition imbalances, resulting in K- and, less surprisingly N-limited production conditions, reflected in low yields of the major crops maize and roselle and low resource use efficiencies. Production on moderate to steep slopes was estimated to result in considerable losses of soil and organic matter. Poor crop production, lack of specific animal fodder production systems and strong dependence on animal grazing within communal areas limited recycling of nutrients through manure. In combination with low prices for the roselle cash crop, farmers are caught in a vicious cycle of cash shortage and resource decline. The production ecological findings complemented farmers opinions by providing more insight in background and extent of livelihood constraints. Changing fertilizer subsidies and rethinking animal fodder production as well as use of communal lands requires targeting both formal and informal governance structures. The methodology has broader applicability in smallholder systems in view of its low demand on capital intensive resource

Exploring the potential for improved internal nutrient cycling in dairy farming systems, using an eco-mathematical model

Nutrient management at Dutch dairy farms is changing rapidly from strong reliance on external inputs to more prudent utilization of internal resources. This paper explores opportunities and constraints arising from this shift towards eco-technological management. A mathematical model of inorganic and organic nitrogen (N) flows in a dairy farming system was formulated based on ecological concepts, integrating processes of nutrient input, recycling, immobilization and mineralization. Recycling is defined as the mineralization of N within the year of its incorporation into herbage, which occurs through release from faeces, animal urine and non-harvested biomass. We simulated changes in inorganic and organic N per hectare, and the consequent emission (E), mineralization (MS) and recycling (R) of N for different initial amounts of inorganic and organic N. Results demonstrate that in the long term, the system evolves to equilibrium amounts of inorganic and organic N, which are strongly determined by the imposed management practices, such as fertilizer input and grassland management. In the short term, moving away from the equilibrium is possible for particular initial amounts of inorganic and organic N. In the equilibrium state, E was reduced by lowering inorganic fertilizer input rate, increasing grassland productivity and improving animal N conversion efficiency, i.e., only by production-related parameters. Only in the short term E was affected by adjustments in quality-related parameters: lower N content, lower digestibility of herbage, reduced degradability of non-harvested biomass and faeces, and parameters determining the functioning of soil biota (degradation rate, efficiency, C/N ratio). Qualityrelated parameters had no effect on internal nutrient cycling in the equilibrium state, because adjustments in MS were completely compensated by changes in R. A comparison of farming systems demonstrated that farming systems can be designed in such a way that improvement of internal nutrient cycling supports the same production with lower inputs and lower emissions

Multicentric validation of proteomic biomarkers in urine specific for diabetic nephropathy

Background: Urine proteome analysis is rapidly emerging as a tool for diagnosis and prognosis in disease states. For diagnosis of diabetic nephropathy (DN), urinary proteome analysis was successfully applied in a pilot study. The validity of the previously established proteomic biomarkers with respect to the diagnostic and prognostic potential was assessed on a separate set of patients recruited at three different European centers. In this case-control study of 148 Caucasian patients with diabetes mellitus type 2 and duration >= 5 years, cases of DN were defined as albuminuria >300 mg/d and diabetic retinopathy (n = 66). Controls were matched for gender and diabetes duration (n = 82). Methodology/Principal Findings: Proteome analysis was performed blinded using high-resolution capillary electrophoresis coupled with mass spectrometry (CE-MS). Data were evaluated employing the previously developed model for DN. Upon unblinding, the model for DN showed 93.8% sensitivity and 91.4% specificity, with an AUC of 0.948 (95% CI 0.898-0.978). Of 65 previously identified peptides, 60 were significantly different between cases and controls of this study. In <10% of cases and controls classification by proteome analysis not entirely resulted in the expected clinical outcome. Analysis of patient's subsequent clinical course revealed later progression to DN in some of the false positive classified DN control patients. Conclusions: These data provide the first independent confirmation that profiling of the urinary proteome by CE-MS can adequately identify subjects with DN, supporting the generalizability of this approach. The data further establish urinary collagen fragments as biomarkers for diabetes-induced renal damage that may serve as earlier and more specific biomarkers than the currently used urinary albumin

Back to the people:The role of community-based responses in shaping landscape trajectories in Oaxaca, Mexico

Land use change results from top-down drivers, such as policies, trade, and migration. Land use change may also result from community-based responses. In Mexico, rural communities govern most of the country's forests. This study aimed to assess how socio-economic and biophysical factors affected the landscape trajectories of rural communities in southern Mexico. It also aimed at evaluating the role of communities in landscape change. Land use change of 63 rural communities was analyzed for the years 1987 and 2017. Four land uses were distinguished: forest, shrubland, agriculture, and bare soil. Five groups of communities were identified according to their socio-economic and biophysical factors. Two groups located in areas with high slopes and elevated marginalization index values showed deforestation patterns. Two other groups, consisting of more than half of the municipalities assessed, showed reforestation trends. The final group did not reveal major changes in land use. Two municipalities with reforestation trends were selected for an in-depth analysis of how community-based responses impacted natural resource management and conservation. Through local assemblies, the population voted for regulations that increased the forest area and reduced the bare soil. There was no evidence that these regulations affected croplands. These results show how a combination of socio-economic and biophysical factors can affect landscape change, but it also shows the often overlooked role of communities as a relevant bottom-up driver of change.</p

The importance of the traditional milpa in food security and nutritional self-sufficiency in the highlands of Oaxaca, Mexico

Around 30% of global food is produced by smallholder farmers, yet they constitute the most food-insecure group. In Mexico, food self-sufficiency is declining. Rural policies in the country have stimulated the production of cash crops to the detriment of the traditional intercropping system, the milpa. Such a decline may have negative consequences for the food security of subsistence farmers. This study aimed to assess changes in nutritional self-sufficiency over the last 30 years and the role of milpa systems in food security for two communities in the highlands of Oaxaca, Mexico. The study used satellite images, censuses, and field data to estimate food production. Three cropping systems, monoculture of maize, monoculture of common bean, and the milpa were compared in terms of nutrients and vitamins produced. Furthermore, a household typology was developed for each community to contrast nutritional self-sufficiency levels between the different household types. Results showed that the milpa produced more volume of food per area compared to the other systems. The milpa also produced all the nutrients and vitamins (except for B12) required to feed at least 2 persons ha-1. Monocultures of maize lacked vitamins A, B9, B12, and C, and the common bean lacked vitamins A, B12, and C. While farmers recognized the importance of the milpa, they preferred monocultures due to the reduced labor demands of this system. Households that obtained most of their income from off-farm activities had the lowest nutritional self-sufficiency. Enhancing nutritional self-sufficiency through crop diversification has the potential to not only improve the nutrition of subsistence farmers, but also to enhance ecosystem service provision, promote biodiversity conservation and restoration, and improve resilience to climate change.</p

Longitudinal analysis of household types and livelihood trajectories in Oaxaca, Mexico

In Mexico, a political shift to fit into neoliberal directives since the 80s has brought several consequences to rural households and their trajectories. This study focused on the relation between drivers of change and household trajectory. The study was carried out in Santa Catarina Tayata, in the state of Oaxaca, Mexico. 44 household heads were interviewed to recall their production system and economic activities at significant moments. The results were summarized as variables describing the socio-economic and agronomic situation of households over three decades: 1988-1997, 1998-2007, and 2008-2017. Household types were identified for each decade. Three household types were distinguishable in the first two decades, and five in the last decade. Drivers of change such as international markets, land tenure, government support, and migration were connected to household trajectories. Results showed that household type diversity increased, while half of the households changed types at one point according to different strategies. Changes in land tenure in the study area in the early 2000s were attributable to the PROCEDE national program, which acted to lift restrictions on land tenure, facilitating the buying and selling of land. The implementation of PROCEDE resulted in fewer households relying on borrowed or rented land while allowing others to expand their land and form a new household type. A migration process enabled some households to invest in land or animal production as a “step up” strategy. The majority of households that received agriculture-related subsidies tended to engage solely in agricultural activities. Half of the households that did not benefit from subsidies engaged in off-farm to diversify their income, suggesting that the type of governmental support can have an impact on farming activities. Household types that had more animal production or larger areas did not tend to engage in off-farm activities because of high demands for labor in their production systems. This type of study can be used to monitor policy impact and households’ strategic responses, to arrive at better articulation of policy objectives and policy impact while considering household type diversity.</p

Renal Effects of Aliskiren Compared With and in Combination With Irbesartan in Patients With Type 2 Diabetes, Hypertension, and Albuminuria

Objective: We investigated if the antiproteinuric effect of the direct renin inhibitor aliskiren is comparable to irbesartan, and the effect of the combination. Research Design and Methods: Double-blind, randomized, cross-over trial. After a one-month washout period 26 patients with type 2 diabetes, hypertension and albuminuria (>100mg/day) were randomized to four 2-month treatment periods in random order with placebo, aliskiren 300 mg once daily, irbesartan 300 mg once daily or the combination using identical doses. Patients received furosemide in a stable dose throughout the study. Primary endpoint was change in albuminuria. Secondary measures included change in 24h blood pressure (24h BP) and glomerular filtration rate (GFR). Results: Placebo geometric mean albuminuria was 258 mg/day (range 84-2361), mean 24h BP was 140/73 (SD 15/8) mmHg, GFR was 89 (SD 27) ml/min/1.73 m(2). Aliskiren treatment reduced albuminuria by 48% (95% confidence interval 27-62) compared to placebo (p<0.001), not significantly different from irbesartan treatment (58% (42-70) (p<0.001 vs. placebo)). Combination treatment reduced albuminuria by 71% (59-79), more than either monotherapy (p<0.001 and p=0.028). Fractional clearances of albumin were significantly reduced (46, 56 and 67% reduction vs. placebo). 24h BP was reduced 3/4 mmHg by aliskiren (NS/p=0.009), 12/5 mmHg by irbesartan (p<0.001/p=0.002) and 10/6 mmHg by the combination (p=0.001/p<0.001). GFR was significantly reduced 4.6 (0.3, 8.8) ml/min/1.73m(2) by aliskiren, 8.0 (3.6, 12.3) ml/min/1.73m(2) by irbesartan and 11.7 (7.4, 15.9) ml/min/1.73m(2) by the combination. Conclusions: Combining aliskiren and irbesartan is more antiproteinuric in type 2 diabetic patients with albuminuria as compared to monotherapy

YKL-40, a Marker of Inflammation and Endothelial Dysfunction, Is Elevated in Patients With Type 1 Diabetes and Increases With Levels of Albuminuria

OBJECTIVE—The inflammation marker YKL-40 is elevated in patients with type 2 diabetes and is associated with atherosclerosis and increased cardiovascular mortality. In the present study, YKL-40 levels were examined in patients with type 1 diabetes with increasing levels of albuminuria, known to be associated with an increased risk of cardiovascular disease