As evaporation of water is an energy-demanding process, increasing evapotranspiration rates decrease the surface temperature (Ts) of leaves and plants. Based on this principle, ground-based thermal ...remote sensing has become one of the most important methods for estimating evapotranspiration and drought stress and for irrigation. This paper reviews its application in agriculture. The review consists of four parts. First, the basics of thermal remote sensing are briefly reviewed. Second, the theoretical relation between Ts and the sensible and latent heat flux is elaborated. A modelling approach was used to evaluate the effect of weather conditions and leaf or vegetation properties on leaf and canopy temperature. Ts increases with increasing air temperature and incoming radiation and with decreasing wind speed and relative humidity. At the leaf level, the leaf angle and leaf dimension have a large influence on Ts; at the vegetation level, Ts is strongly impacted by the roughness length; hence, by canopy height and structure. In the third part, an overview of the different ground-based thermal remote sensing techniques and approaches used to estimate drought stress or evapotranspiration in agriculture is provided. Among other methods, stress time, stress degree day, crop water stress index (CWSI), and stomatal conductance index are discussed. The theoretical models are used to evaluate the performance and sensitivity of the most important methods, corroborating the literature data. In the fourth and final part, a critical view on the future and remaining challenges of ground-based thermal remote sensing is presented.
Response inhibition is crucial for mental and physical health but studies assessing the trainability of this type of inhibition are rare. Thirty‐nine children aged 10‐12 years and 46 adults aged ...18‐24 years were assigned to an adaptive go/no‐go inhibition training condition or an active control condition. Transfer of training effects to performance on tasks assessing response inhibition, interference control, working memory updating, task‐switching, and non‐verbal fluid intelligence were assessed during 3‐ and 6‐month follow‐up sessions and/or an immediate post‐training session. Significant training improvements and positive transfer effects to a similar response inhibition task with other stimuli were observed for both children and adults. Reliable albeit short‐lived transfer effects were only found for the children, specifically to working memory updating and task switching. These results suggest some potential for response‐inhibition training programs to enhance aspects of cognitive functioning in children but not adults.
A group of young adults and 10−12‐year old children were either trained on an adaptive multiple‐session response inhibition task or performed a control activity. The trained participants from both age groups displayed significant improvements during training and positive transfer to a similar inhibition task. Reliable, albeit short‐lived, transfer effects were only found for the children, specifically to working memory updating and task‐switching tasks.
Although 40% of the global population relies on traditional biomass use, mainly firewood and charcoal, for cooking, traditional biomass has received very little attention in the current biomass ...debate, because of its considered primitive and unsustainable nature. In this review, we discuss how the sustainability of household cooking in developing countries can be improved.
Indoor air pollution due to incomplete combustion of traditional biomass causes the death of 1.45 million people every year, mainly of women and children, who also carry the heavy burden of fuelwood collection. In addition, charcoal production and combustion is responsible for very high greenhouse gas emissions per unit of energy. On the other hand, fuelwood production and trade is of vital importance for local economies and serves as safety net for the poorest people. Moreover, fuelwood collection is not a driver of deforestation and global fuelwood shortage will not occur, despite local problems of fuelwood provision.
There are two distinct policy alternatives to increase the sustainability of cooking in developing countries. The first option is to climb the energy ladder and to switch from solid fuels to fossil fuels (LPG or kerosene), biogas or electricity. As this largely avoids the severe health damages of traditional biomass use, this option is considered the most desirable by numerous countries and by international organizations. However, as most developing countries are far away from meeting the necessary requirements, related to infrastructure, economics and local culture, expecting a large-scale switch to liquid fuels or electricity is unrealistic.
In that case, the second policy option, increasing the sustainability of the current traditional biomass system, must be considered. This can be realized by an integrated approach, in which national and regional fuelwood policies are adapted, improved systems for charcoal production are implied and improved stoves, in combination with chimneys, are distributed.
Remote sensing with unmanned aerial vehicles (UAVs) is a game-changer in precision agriculture. It offers unprecedented spectral, spatial, and temporal resolution, but can also provide detailed ...vegetation height data and multiangular observations. In this article, we review the progress of remote sensing with UAVs in drought stress, in weed and pathogen detection, in nutrient status and growth vigor assessment, and in yield prediction. To transfer this knowledge to everyday practice of precision agriculture, future research should focus on exploiting the complementarity of hyperspectral or multispectral data with thermal data, on integrating observations into robust transfer or growth models rather than linear regression models, and on combining UAV products with other spatially explicit information.
Drought stress detection with unmanned aerial vehicles (UAVs) relies mainly on thermal imagery.
Pathogen detection with UAVs is relatively premature, but fusion of thermal and hyperspectral data shows great potential.
Weed detection with UAVs based on object-based image analysis is in an advanced stage, and can be used for site-specific weed management.
Nutrient status assessment and yield prediction with UAVs are promising, but integration with models can improve its applicability.
Evaporation (E) and transpiration (T) respond differently
to ongoing changes in climate, atmospheric composition, and land use. It is
difficult to partition ecosystem-scale evapotranspiration (ET) ...measurements
into E and T, which makes it difficult to validate satellite data and land
surface models. Here, we review current progress in partitioning E and T and
provide a prospectus for how to improve theory and observations going
forward. Recent advancements in analytical techniques create new
opportunities for partitioning E and T at the ecosystem scale, but their
assumptions have yet to be fully tested. For example, many approaches to
partition E and T rely on the notion that plant canopy conductance and
ecosystem water use efficiency exhibit optimal responses to atmospheric
vapor pressure deficit (D). We use observations from 240 eddy covariance flux
towers to demonstrate that optimal ecosystem response to D is a reasonable
assumption, in agreement with recent studies, but more analysis is necessary
to determine the conditions for which this assumption holds. Another
critical assumption for many partitioning approaches is that ET can be
approximated as T during ideal transpiring conditions, which has been
challenged by observational studies. We demonstrate that T can exceed 95 %
of ET from certain ecosystems, but other ecosystems do not appear to reach
this value, which suggests that this assumption is ecosystem-dependent with
implications for partitioning. It is important to further improve approaches
for partitioning E and T, yet few multi-method comparisons have been
undertaken to date. Advances in our understanding of carbon–water coupling
at the stomatal, leaf, and canopy level open new perspectives on how to
quantify T via its strong coupling with photosynthesis. Photosynthesis can be
constrained at the ecosystem and global scales with emerging data sources
including solar-induced fluorescence, carbonyl sulfide flux measurements,
thermography, and more. Such comparisons would improve our mechanistic
understanding of ecosystem water fluxes and provide the observations
necessary to validate remote sensing algorithms and land surface models to
understand the changing global water cycle.
Previous research revealed associations between an individual's occupation and cognitive abilities. However, the underlying causal relation is not always clear and only few studies focused on a ...critical component of executive functioning, namely working memory updating (WMU). Study 1 examined whether restaurant ticket collectors (N = 53) have a better WMU ability compared to a group of security guards (N = 49) that was matched on relevant variables. Study 2 examined transfer effects of a computerized working memory training program in students. The program simulated elements of a restaurant ticket collector's daily work requirements. In Study 1, the ticket collectors performed better than the guards on WMU tasks. In Study 2, using an active control group (N = 33) as comparison, the trained students (N = 33) displayed beneficial training effects on transfer WMU tasks but not on general intelligence tasks. The results support the general notion of repeated experience with occupation‐specific demands affecting specific objectively‐assessed cognitive abilities.
Objectives Many employees with burnout report cognitive difficulties. However, the relation between burnout and cognitive functioning has hardly been empirically validated. Moreover, it is unknown ...whether the putative cognitive deficits in burnout are temporary or permanent. Therefore, the purpose of the study was to answer two related questions: (i) Is burnout associated with self-reported cognitive difficulties and with deficits in a specific and well-defined set of executive functions? (ii) Do these putative self-reported cognitive difficulties and deficits in executive functioning in burnout diminish after a 10-week period with cognitive behavioral therapy? Methods Sixteen employees with burnout were compared with sixteen matched healthy employees on selfreported cognitive difficulties and tests measuring the basic executive functions, namely, updating, inhibition, and switching, on two test occasions. The interval between the test occasions was ten weeks, during which the burnout individuals received cognitive behavioral therapy. Results On the first test occasion, and relative to healthy individuals, individuals with burnout reported more cognitive difficulties and showed deficits in the "updating" function. No group differences were found regarding the "inhibition" and "switching" functions, although individuals with burnout generally responded slower than healthy individuals on the latter test. Even though after the ten-week treatment period individuals with burnout revealed positive changes regarding burnout symptoms, general health, and self-reported cognitive difficulties, no evidence was found for improved cognitive test performance. Conclusions These findings suggest that either (i) burnout leads to permanent cognitive deficits, (ii) subjective burnout complaints reduce faster than deficits in cognitive test performance, or (iii) cognitive deficits are a cause rather than a consequence of burnout.
The capacity to switch between tasks is a central component of executive functioning. Previous studies assessing effects of task-switch training have revealed mixed results, both in terms of ...processes that may be improved and the extent of beneficial effects on non-trained tasks. These studies primarily used few training sessions, which may have limited training and transfer effects. Here, 31 students were trained for 21 days on a cued switching task. Both the trained group and an active control group (
n
= 29) performed a number of cognitive tasks before and after training. Training reduced both switch and mixing costs, which mostly reached an asymptote after approximately four to six training sessions, although there were residual costs at the end of training. The switch cost reduction was restricted to trials with a short cue–stimulus onset interval (CSI). Training benefitted performance on another switching task, reflecting near transfer. However, this benefit was limited to the switch cost and to trials with a short CSI. There were no beneficial effects on far-transfer tasks measuring interference control, response inhibition, working memory, and general IQ. The results suggest that the present extensive training protocol, implicating overtraining, specifically enhanced the efficiency of processes involved in preparing for the relevant upcoming task set and/or inhibition of the previous task set. However, the lack of beneficial far-transfer effects is in line with previous cognitive training studies employing fewer training sessions, suggesting that the extent of training is not critical for (not) finding transfer effects.
The development of UAVs and multispectral cameras has led to remote sensing applications with unprecedented spatial resolution. However, uncertainty remains on the radiometric calibration process for ...converting raw images to surface reflectance. Several calibration methods exist, but the advantages and disadvantages of each are not well understood. We performed an empirical analysis of five different methods for calibrating a 10-band multispectral camera, the MicaSense RedEdge MX Dual Camera System, by comparing multispectral images with spectrometer measurements taken in the field on the same day. Two datasets were collected, one in clear-sky and one in overcast conditions on the same field. We found that the empirical line method (ELM), using multiple radiometric reference targets imaged at mission altitude performed best in terms of bias and RMSE. However, two user-friendly commercial solutions relying on one single grey reference panel were only slightly less accurate and resulted in sufficiently accurate reflectance maps for most applications, particularly in clear-sky conditions. In overcast conditions, the increase in accuracy of more elaborate methods was higher. Incorporating measurements of an integrated downwelling light sensor (DLS2) did not improve the bias nor RMSE, even in overcast conditions. Ultimately, the choice of the calibration method depends on required accuracy, time constraints and flight conditions. When the more accurate ELM is not possible, commercial, user-friendly solutions like the ones offered by Agisoft Metashape and Pix4D can be good enough.
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