The mitochondrial permeability transition (MPT) is a death-inducing mechanism that collapses electrochemical gradients across inner mitochondrial membranes. Several studies in model plants have ...detailed potential MPT-dependent cell death upon abiotic stress in response to heat shock, ultraviolet radiation, heavy metal toxicity and waterlogging. However, the molecular specifics of the MPT and its possible role on plant cell death remain controversial. This review addresses previous and recent developments on the role(s) of the MPT in plants. Considering these advances, MPT targeting can constitute a plausible strategy to ameliorate cell death in plants upon abiotic stress.
•The mitochondrial permeability transition can induce cell death.•Current studies in plants suggest this transition shows species-specific characteristics.•Targeting mitochondrial permeability transition may protect plants from abiotic stress.
Opening of the mitochondrial permeability transition pore is the underlying cause of cellular dysfunction during diverse pathological situations. Although this bioenergetic entity has been studied ...extensively, its molecular componentry is constantly debated. Cyclophilin D is the only universally accepted modulator of this channel and its selective ligands have been proposed as therapeutic agents with the potential to regulate pore opening during disease.
This review aims to recapitulate known molecular determinants necessary for Cyclophilin D activity regulation and binding to proposed pore constituents thereby regulating the mitochondrial permeability transition pore.
While the main target of Cyclophilin D is still a matter of further research, permeability transition is finely regulated by post-translational modifications of this isomerase and its catalytic activity facilitates pore opening.
Complete elucidation of the molecular determinants required for Cyclophilin D-mediated control of the mitochondrial permeability transition pore will allow the rational design of therapies aiming to control disease phenotypes associated with the occurrence of this unselective channel. This article is part of a Special Issue entitled Proline-directed Foldases: Cell Signaling Catalysts and Drug Targets.
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•The mitochondrial permeability transition compromises cellular homeostasis.•Candidates thought to form the channel unit of the mitochondrial permeability transition pore have not ...passed loss-of-function genetic tests.•Alternative working models on the channel forming unit(s) of the mitochondrial permeability transition pore still await validation.•Future studies should follow standard guidelines to identify the channel-forming unit(s) of the mitochondrial permeability transition pore.
Mitochondria from different organisms can undergo a sudden process of inner membrane unselective leakiness to molecules known as the mitochondrial permeability transition (MPT). This process has been studied for nearly four decades and several proteins have been claimed to constitute, or at least regulate the usually inactive pore responsible for this transition. However, no protein candidate proposed as the actual pore-forming unit has passed rigorous gain- or loss-of-function genetic tests. Here we review evidence for -and against- putative channel-forming components of the MPT pore. We conclude that the structure of the MPT pore still remains largely undefined and suggest that future studies should follow established technical considerations to unambiguously consolidate the channel forming constituent(s) of the MPT pore.
Digital surface models (DSMs) extracted from 15 different stereo pairs attained by the combination of GeoEye-1 (GE1) and WorldView-2 (WV2) panchromatic very high resolution (VHR) satellite images are ...tested. Two of them are pure same-date along-track stereo pairs, one from each VHR satellite, whereas the rest are mixed multidate across-track ones. A quality assessment on the DSMs extracted from the aforementioned stereo pairs, involving both accuracy and completeness, is carried out. Several factors are tested such as sensor model used in the bundle adjustment, number of ground control points (GCPs), radiometric characteristics, satellite imaging geometry, time between acquisition dates, and target land cover. A highly accurate light detection and ranging elevation data is used as ground truth. Overall, 3-D rational functions refined by a zero-order polynomial adjustment by using 7 or 12 GCPs performed slightly better regarding both DSM vertical accuracy and completeness. In relation to the pure stereo pairs, the DSM extracted from the GE1 stereo pair attained better vertical accuracy over the whole study area (90th percentile linear error, LE90, of 2.04 m) but lower completeness (74.50%) than the WV2 one (2.56 m and 83.35%, respectively). The undergoing hypothesis is that the blurrier images from WV2 could have influenced in the improvement of the matching success rate while reducing the vertical accuracy of extracted points. When all the 15 stereo pairs are considered, the vertical accuracy mainly depends on the convergence angle. In addition, the temporal difference between acquisition dates turned out to be the most influential factor regarding completeness values.
Plastic-covered greenhouse (PCG) segmentation represents a significant challenge for object-based PCG mapping studies due to the spectral characteristics of these singular structures. Therefore, the ...assessment of PCG segmentation quality by employing a multiresolution segmentation algorithm (MRS) was addressed in this study. The structure of this work is composed of two differentiated phases. The first phase aimed at testing the performance of eight widely applied supervised segmentation metrics in order to find out which was the best metric for evaluating image segmentation quality over PCG land cover. The second phase focused on examining the effect of several factors (reflectance storage scale, image spatial resolution, shape parameter of MRS, study area, and image acquisition season) and their interactions on PCG segmentation quality through a full factorial analysis of variance (ANOVA) design. The analysis considered two different study areas (Almeria (Spain) and Antalya (Turkey)), seasons (winter and summer), image spatial resolution (high resolution and medium resolution), and reflectance storage scale (Percent and 16Bit formats). Regarding the results of the first phase, the Modified Euclidean Distance 2 (MED2) was found to be the best metric to evaluate PCG segmentation quality. The results coming from the second phase revealed that the most critical factor that affects MRS accuracy was the interaction between reflectance storage scale and shape parameter. Our results suggest that the Percent reflectance storage scale, with digital values ranging from 0 to 100, performed significantly better than the 16Bit reflectance storage scale (0 to 10,000), both in the visual interpretation of PCG segmentation quality and in the quantitative assessment of segmentation accuracy.
Plastic-covered greenhouses (PCG) have been extensively used in agricultural practices around the world. Remote sensing based on spectral indices is a key asset to monitor the spatial distribution of ...these structures on a large scale. The primary objective of this research was to conduct a comprehensive benchmarking of the available spectral indices based on Sentinel-2 data for large-scale PCG mapping. For that, eight PCG indices were thoroughly analyzed by systematically investigating their optimal thresholds in five study sites located in Almería (Spain), Antalya (Turkey), Agadir (Morocco), Weifang (China), and Nantong (China), including also different growing seasons. The experimental results demonstrated that the Plastic GreenHouse Index (PGHI) achieved the best PCG mapping accuracy in almost all study sites and growing seasons tested. From the visual analysis carried out on the PGHI mapping results, it was made out that the main misclassification between PCG and background classes took place in water bodies and industrial building land covers, particularly in the Weifang and Nantong study areas. Based on this fact, the original version of PGHI was modified by adding two processes aimed at masking water bodies and industrial buildings. This new composite index, called Improved PGHI (IPGHI), attained better accuracy results in all study sites, especially in Chinese PCG areas. The average F1 score calculated for all the study cases improved from 86.05% using PGHI to 90.51% applying IPGHI. The new approach provided a significant and robust improvement in PCG large-scale mapping for several types of PCG sites, even considering different growing seasons.
The total area of plastic-covered crops of 3019 million hectares has been increasing steadily around the world, particularly in the form of crops maintained under plastic-covered greenhouses to ...control their environmental conditions and their growth, thereby increasing production. This work analyzes the worldwide research dynamics on remote sensing-based mapping of agricultural greenhouses and plastic-mulched crops throughout the 21st century. In this way, a bibliometric analysis was carried out on a total of 107 publications based on the Scopus database. Different aspects of these publications were studied, such as type of publication, characteristics, categories and journal/conference name, countries, authors, and keywords. The results showed that “articles” were the type of document mostly found, while the number of published documents has exponentially increased over the last four years, growing from only one document published in 2001 to 22 in 2019. The main Scopus categories relating to the topic analyzed were Earth and Planetary Sciences (53%), Computer Science (30%), and Agricultural and Biological Sciences (28%). The most productive journal in this field was “Remote Sensing”, with 22 documents published, while China, Italy, Spain, USA, and Turkey were the five countries with the most publications. Among the main research institutions belonging to these five most productive countries, there were eight institutions from China, four from Italy, one from Spain, two from Turkey, and one from the USA. In conclusion, the evolution of the number of publications on Remote Sensing of Agricultural Greenhouses and Plastic-Mulched Farmland found throughout the period 2000–2019 allows us to classify the subject studied as an emerging research topic that is attracting an increasing level of interest worldwide, although its relative significance is still very limited within the remote sensing discipline. However, the growing demand for information on the arrangement and spatio-temporal dynamics of this increasingly important model of intensive agriculture is likely to drive this line of research in the coming years.
Vanadium compounds have been primarily investigated as potential therapeutic agents for the treatment of various major health issues, including cancer, atherosclerosis, and diabetes. The translation ...of vanadium-based compounds into clinical trials and ultimately into disease treatments remains hampered by the absence of a basic pharmacological and metabolic comprehension of such compounds. In this review, we examine the development of vanadium-containing compounds in biological systems regarding the role of the physiological environment, dosage, intracellular interactions, metabolic transformations, modulation of signaling pathways, toxicology, and transport and tissue distribution as well as therapeutic implications. From our point of view, the toxicological and pharmacological aspects in animal models and humans are not understood completely, and thus, we introduced them in a physiological environment and dosage context. Different transport proteins in blood plasma and mechanistic transport determinants are discussed. Furthermore, an overview of different vanadium species and the role of physiological factors (i.e., pH, redox conditions, concentration, and so on) are considered. Mechanistic specifications about different signaling pathways are discussed, particularly the phosphatases and kinases that are modulated dynamically by vanadium compounds because until now, the focus only has been on protein tyrosine phosphatase 1B as a vanadium target. Particular emphasis is laid on the therapeutic ability of vanadium-based compounds and their role for the treatment of diabetes mellitus, specifically on that of vanadate- and polioxovanadate-containing compounds. We aim at shedding light on the prevailing gaps between primary scientific data and information from animal models and human studies.
•High quality DSM and DTM from WV2 imagery over very dense greenhouse covered areas.•DSM/DTM are valuable to compute the height of all overlying objects on the terrain.•The normalized DSM could be ...used to complement spectral information in PCG mapping.
Agriculture under Plastic Covered Greenhouses (PCG) has represented a step forward in the evolution from traditional to industrial farming. However, PCG-based agricultural model has been also criticized for its associated environmental impact such as plastic waste, visual impact, soil pollution, biodiversity degradation and local runoff alteration. In this sense, timely and effective PCG mapping is the only way to help policy-makers in the definition of plans dealing with the trade-off between farmers’ profit and environmental impact for the remaining inhabitants.
This work proposes a methodological pipeline for producing high added value 3D geospatial products (Digital Surface Models (DSM) and Digital Terrain Models (DTM)) from VHR satellite imagery over PCG areas. The 3D information layer provided through the devised approach could be very valuable as a complement to the traditional 2D spectral information offered by VHR satellite imagery to improve PCG mapping over large areas.
This methodological approach has been tested in Almeria (Southern Spain) from a WorldView-2 VHR satellite stereo-pair. Once grid spacing format DSM and DTM were built, their vertical accuracy was assessed by means of lidar data provided by the Spanish Government (PNOA Programme).
Regarding DSM completeness results, the image matching method based on hierarchical semi-global matching yielded much better scores (98.87%) than the traditional image matching method based on area-based matching and cross-correlation threshold (86.65%) when they were tested on the study area with the highest concentration of PCG (around 85.65% of PCG land cover). However, both image matching methods yielded similar vertical accuracy results in relation to the finally interpolated DSM, with mean errors ranging from 0.01 to 0.35 m and random errors (standard deviation) between 0.56 and 0.82 m. The DTM error figures also showed no significant differences between both image matching methods, although being highly dependent on DSM-to-DTM filtering error, in turn closely related to greenhouse density and terrain complexity.
The mitochondrion relies on compartmentalization of certain enzymes, ions and metabolites for the sake of efficient metabolism. In order to fulfil its activities, a myriad of carriers are properly ...expressed, targeted and folded in the inner mitochondrial membrane. Among these carriers, the six-transmembrane-helix mitochondrial SLC25 (solute carrier family 25) proteins facilitate transport of solutes with disparate chemical identities across the inner mitochondrial membrane. Although their proper function replenishes building blocks needed for metabolic reactions, dysfunctional SLC25 proteins are involved in pathological states. It is the purpose of the present review to cover the current knowledge on the role of SLC25 transporters in health and disease.
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