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Satellite passive microwaves reveal recent climate-induced carbon losses in African drylands

The African continent is facing one of the driest periods in the past three decades as well as continued deforestation. These disturbances threaten vegetation carbon (C) stocks and highlight the need for improved capabilities of monitoring large-scale aboveground carbon stock dynamics. Here we use a satellite dataset based on vegetation optical depth derived from low-frequency passive microwaves (

Woody plant cover estimation in drylands from Earth Observation based seasonal metrics

From in situ measured woody cover we develop a phenology driven model to estimate the canopy cover of woody species in the Sahelian drylands at 1km scale. The model estimates the total canopy cover of all woody phanerophytes and the concept is based on the significant difference in phenophases of dryland trees, shrubs and bushes as compared to that of the herbaceous plants. Whereas annual herbaceo

Global-scale mapping of changes in ecosystem functioning from earth observation-based trends in total and recurrent vegetation

Aim: To evaluate trend analysis of earth observation (EO) dense time series as a new way of describing and mapping changes in ecosystem functioning at regional to global scales. Spatio-temporal patterns of change covering 1982-2011 are discussed in the context of changes in land use and land cover (LULCC). Location: Global. Methods: This study takes advantage of the different phenological cycles o

A Routing Protocol for LoRA Mesh Networks

A limitation of current LoRa networks is their single-hop nature. This causes difficulties in areas with poor Internet access, such as remote rural areas, or challenging radio environments, for example in metropolitan areas, as the LoRa gateway must be placed at a location with backhaul access to the network server, but must nonetheless be reachable by all end devices. To facilitate these applicatA limitation of current LoRa networks is their single-hop nature. This causes difficulties in areas with poor Internet access, such as remote rural areas, or challenging radio environments, for example in metropolitan areas, as the LoRa gateway must be placed at a location with backhaul access to the network server, but must nonetheless be reachable by all end devices. To facilitate these applicat

Reduction of tree cover in West African woodlands and promotion in semi-arid farmlands

Woody vegetation in farmland acts as a carbon sink and provides ecosystem services for local people, but no macroscale assessments of the impact of management and climate on woody cover exist for drylands. Here we make use of very high spatial resolution satellite imagery to derive wall-to-wall woody cover patterns in tropical West African drylands. Our study reveals that mean woody cover in farml

Protecting Wireless Mesh Networks Against Adverse Weather Conditions

Adverse weather conditions can cause deterioration of wireless channels, leading to reduced link capacities. Unlike in other types of networks, in radio-based wireless mesh networks, the link capacities depend not only on the prevailing conditions, but also on interfering transmissions, as well as the transmission power and modulation and coding schemes used. This leads to increased difficulty in Adverse weather conditions can cause deterioration of wireless channels, leading to reduced link capacities. Unlike in other types of networks, in radio-based wireless mesh networks, the link capacities depend not only on the prevailing conditions, but also on interfering transmissions, as well as the transmission power and modulation and coding schemes used. This leads to increased difficulty in

Climate contributions to vegetation variations in Central Asian drylands : Pre- and post-USSR collapse

Central Asia comprises a large fraction of the world's drylands, known to be vulnerable to climate change. We analyzed the inter-annual trends and the impact of climate variability in the vegetation greenness for Central Asia from 1982 to 2011 using GIMMS3g normalized difference vegetation index (NDVI) data. In our study, most areas showed an increasing trend during 1982-1991, but experienced a si

Assessment of lactate production as a response to sustained intrapartum hypoxia in large-for-gestational-age newborns.

Introduction Lactate concentration in umbilical cord blood is an important measure of intrapartum anaerobic metabolism. The aim of the study was to compare lactate production of large‐for‐gestational‐age (LGA) fetuses against appropriate‐for‐gestational‐age (AGA) fetuses during hypoxia, in diabetic and non‐diabetic mothers. Material and methods A total of 17 358 validated paired arterial and ven