Extreme Shifts Research Articles

Mobile mecavision: automatic plant monitoring system as a precision agriculture solution in plant factories

Precision agriculture (PA) is an approach in farming systems based on information and technology to enhance agricultural production. PA is applied in plant factories to produce high-quality vegetables in a controlled environment by implementing an automatic crop growth monitoring system. Optimization of the observation process carried out with computer system techniques used in the monitoring process and assessment of the plant condition. Individual observation of cultivated plants requires a monitoring system and numerous equipment. Therefore, a monitoring system equipped with a mobile mechanism is needed to support the monitoring process of crops individually by a single observer. The objective of this study was to design and implement an automatic plant monitoring system based on mobile mechanisms and computer vision using simple equipment in plant factories. The Mobile Mecavision, a monitoring system consists of a mobility system and an image acquisition system controlled by Raspberry Pi. The components are A4988, NEMA 17, and Logitech C270 HD Webcam. The evaluation for system performance carried out using the extreme point shift system and t-test. The aspect of image functionality evaluated using the Structural Similarity Measure test and the result was obtained an image similarity value of 89% to 92% with a 90% level of confidence. The result of the performance test on the mobility aspect obtained that the system shifted numerically but not statistically. The overall performance of the system indicated that the monitoring system could be applied to monitor the crop growth in plant factories.

Effects of extreme temperature on China’s tea production

The production of tea (Camellia sinensis (L.) Kuntze), the world’s second most consumed beverage, is susceptible to extreme weather events. However, our understanding about the impacts of extreme temperatures and climate change on tea yields remains fairly limited. Here we quantify the historical and predict future fluctuations in tea yield caused by extreme temperatures in China, the largest tea producing country. We found that both heat and cold extremes were associated with significantly reduced tea yields. In the present climate, dominating cold extremes influence more than half of China’s tea production, with a maximum of 56.3% reduced annual production. In the near future, we predict positive net impacts of climate change on tea yield in all study regions at both the 1.5 °C and 2.0 °C global warming levels. Climate warming may diminish the negative impacts of cold extremes to 14%, especially at the current most affected northern tea growing regions (>28° N). However, new areas of yield reduction by intensified heat extremes will emerge, up to 14%–26% yield losses estimated at the Yangtze River (∼30° N) and southern China (<∼25° N) regions. Although the Paris Agreement targets limiting global warming to 1.5 °C, we expect up to 11%–24% heat-induced yield loss in Chongqing, Hunan, Anhui, and Zhejiang. Increasing heat extremes pose the most challenging changes for tea production in China. Therefore, addressing the regional difference of extreme temperature shifts is urgent for adapting tea production to climate change.

Predicting Extreme Daily Regime Shifts in Financial Time Series Exchange/Johannesburg Stock Exchange—All Share Index

During the past decades, seasonal autoregressive integrated moving average (SARIMA) had become one of a prevalent linear models in time series and forecasting. Empirical research advocated that forecasting with non-linear models can be an encouraging alternative to traditional linear models. Linear models are often compared to non-linear models with mixed conclusions in terms of superiority in forecasting performance. Therefore, the aim of this study is to build an early warning system (EWS) model for extreme daily losses for financial stock markets. A logistic model tree (LMT) is used in collaboration with a seasonal autoregressive integrated moving average-Markov-Switching exponential generalised autoregressive conditional heteroscedasticity-generalised extreme value distribution (SARIMA-MS-EGARCH-GEVD) estimates. A time series of the study is a five-day financial time series exchange/Johannesburg stock exchange-all share index (FTSE/JSE-ALSI) for the period of 4 January 2010 to 31 July 2020. The study is set into a two-stage framework. Firstly, SARIMA model is fitted to stock returns in order to obtain independently and identically distributed (i.i.d) residuals and fit the MS(k)-EGARCH(p,q)-GEVD to i.i.d residuals; while, in the second stage, we set-up an EWS model. The results of the estimated MS(2)-EGARCH(1,1) -GEVD revealed that the conditional distribution of returns is highly volatile giving the expected duration to approximately 36 months and 4 days in regime one and 58 months and 2 days in regime two. We further found that any degree losses above 25% implies that there will be no further losses. Using the seven statistical loss functions, the estimated SARIMA(2,1,0)×(2,1,0)240−MS(2)−EGARCH(1,1)−GEVD proved to be the most appropriate model for predicting extreme regimes losses as it was ranked at 71%. Finally, the results of EWS model exhibit reasonably an overall performance of 98%, sensitivity of 79.89% and specificity of 98.40% respectively. The model further indicated a success classification rate of 89% and a prediction rate of 95%. This is a promising technique for EWS. The findings also confirmed 63% and 51% of extreme losses for both training sample and validation sample to be correctly classified. The findings of this study are useful for decision makers and financial sector for future use and planning. Furthermore, a base for future researchers for conducting studies on emerging markets, have been contributed. These results are also important to risk managers and and investors.

Seasonal evolution differences of east Asian summer monsoon precipitation between Bølling-Allerød and younger Dryas periods

The rapid warming trend during the last deglaciation triggered significant global climate instabilities due to a complex non-linear response of the climate system to the gradual increase in insolation over the northern hemisphere. Although climate impacts can be detected globally, major regional imprints such as seasonal evolution and changes of the East Asian Summer Monsoon (EASM) during the last deglaciation are still poorly constrained due to a lack of comprehensive proxy data. In this study, we compare how the extreme climate shifts are linked to changes in EASM precipitation over China between the unusually warm Bolling-Allerod (BA) interstadial and the following strong cooling of the Younger Dryas (YD) stadial. Our analysis is based on the transient atmosphere-ocean simulations of TraCE-21ka, in addition to new results from high-resolution simulations of the CESM1 model for the BA and YD time slices. We find that the earlier onset and stronger intensity of the EASM in the BA interstadial lead to more precipitation in early summer (May–June) but drier conditions during mid-summer (July–August) over Southern China compared to a stadial climate during the YD episode. For Northern China, we find the opposite response. The insolation change in spring and the forced response of the atmospheric system are thought to be responsible for these differences. Relative to the YD episode, the hemispheric temperature gradient during the BA period is enhanced due to the asymmetric warming between the two hemispheres, leading to an intensified northward equatorial cross flow. Combined with a stronger sensible heating of the Tibetan Plateau in spring and the related earlier northward shift of the westerly jet, the early onset of the EASM is triggered. The latent heat release, which is accompanied by the onset of the EASM and the sudden increasing precipitation over Southern China in early summer, contributes to the westward shift of the Western Pacific Subtropical High (WPSH) and eastward movement of the South Asia High (SAH) in mid-summer. Under the above conditions, Southern China experiences a hot and dry climate, while Northern China receives more precipitation. Additionally, the La Nina-like pattern of the equatorial Pacific also partly contributes to the strong EASM in the warm period by influencing the WPSH location and Pacific-North American (PNA) teleconnection pattern.

Extreme High-velocity Outflows from High-redshift BOSS Quasars

Abstract It is common to assume that all narrow absorption lines (NALs) at extreme high-velocity shifts form in cosmologically intervening gas or galaxies unrelated to quasars. However, previous detailed studies of individual quasars have shown that some NALs at these large velocity shifts do form in high-speed quasar ejecta. We search for extreme high-velocity NAL outflows (with speeds ∼0.1c–0.2c) based on relationships with associated absorption lines (AALs) and broad absorption-line (BAL) outflows. We find that high-velocity NALs are strongly correlated with AALs, BALs, and radio loudness, indicating that a significant fraction of high-velocity systems are either ejected from the quasars or form in material swept up by the radio jets (and are not unrelated intervening gas). We also consider line-locked C iv doublets as another indicator of high-velocity NALs formed in outflows. The fact that line-locked NALs are highly ionized and correlated with BAL outflows and radio-loud quasars implies that physical line locking due to radiative forces is both common and real, which provides indirect evidence that a significant fraction of high-velocity NALs are intrinsic to quasars.

Extremal Shift Rule and Viability Property for Mean Field-Type Control Systems

We investigate when a mean field-type control system can fulfill a given constraint. Namely, given a closed set of probability measures on the torus, starting from any initial probability measure belonging to this set, does there exist a solution to the mean field control system remaining in it for any time? This property—the so-called viability property—is equivalently characterized through a property involving normals to the given set of probability measures. We prove that, if the Hamiltonian is nonpositive at any normal distribution to the given set, then the feedback strategy realizing the extremal shift rule provides the approximate viability. This implies the usual viability property. Conversely, the Hamiltonian is nonpositive at any normal distribution if the given set is viable. Our approach enables us to derive generalized feedback laws which ensure the trajectory to fulfill the constraint. This generalized feedback called here extremely shift rule is inspired by constructive motions developed by Krasovskii and Subbotin for differential games.

Sustainable Aqueous Phase Separation membranes prepared through mild pH shift induced polyelectrolyte complexation of PSS and PEI

pH shift induced Aqueous phase separation (APS) is a novel and more sustainable water-based approach to create microfiltration, ultrafiltration, and nanofiltration membranes. APS allows for control over membrane pore size and structure in ways analogous to traditional non-solvent induced phase separation (NIPS). Unfortunately, existing APS approaches require extreme pH shifts (from pH 14 to pH 1) to obtain successful membranes, limiting their applicability for large scale production. Here we demonstrate that APS membranes, with tunable pore sizes ranging from ~80 nm to dense nanofiltration type, can be prepared using a mild pH shift (pH 12 to pH 4) based on the complexation of poly(styrene sulfonate) (PSS) and branched polyethyleneimine (PEI) in acetate buffer coagulation baths. The molecular weight of PEI, the concentration and the pH value of the buffer solution, and the concentration of glutaraldehyde cross-linking agent were systematically varied to control and optimize the membrane fabrication conditions. It was found that tight nanofiltration membranes having a molecular weight cut-off of ~200 g mol−1 and excellent salt (97% MgCl2) and micropollutant retentions (~96%) could be prepared alongside ultra/microfiltration type membranes with an average pore size of ~60 nm. These results indicate that APS membranes with tunable pore sizes can be prepared under mild pH conditions with excellent control over separation properties.

Phase diagrams and microstructures of aqueous short alkyl chain polyethylene glycol ether carboxylate and carboxylic acid triblock surfactant solutions

HypothesisThe surfactant C8EO8CH2COOH (Akypo LF2) and its salts have a small hydrophobic and a significantly longer hydrophilic part. As a consequence, there must be a significant steric constraint, once these surfactant molecules form micelles. In addition, the partially charged headgroups should bring some additional fine-tuning via electrostatic interactions to this “essentially non-ionic” surfactant. ExperimentsPhase diagrams of binary mixtures of water and C8EO8CH2COOH are established over large concentration and temperature ranges, also at different pHs and in the presence of sodium and calcium ions. Surface tensions and osmotic pressures are measured to understand the systems. To evaluate the microstructures, also Dynamic Light Scattering and Small-Angle X-ray Scattering are performed. FindingsApart from the formation of coacervates at very low surfactant concentrations, spherical micelles persist over the whole concentration and temperature range and do not change in size and shape. At very high surfactant concentrations, above 60% by weight, where the headgroups are no longer fully hydrated, the standard core-shell structure of micelles vanishes and highly stabilized aggregates of 8–26 octyl chains are suspended in interdigitated polyoxyethylene layers and form an “osmotic brush”. When the acid is partially transformed to a sodium salt, the repulsion between the micelles increases, whereas bridging between micelles prevails, when the counterions are calcium cations. Remarkably, the negative charges of the headgroups are randomly distributed in the hydrophilic ethylene oxide shell. Altogether, a phase diagram without lyotropic liquid crystalline phases and an extreme shift of the cloud-point in temperature and composition is found, similar to the phase diagram of C8EO8OH already known in literature. The phase properties can be explained by the curvature and packing constraints together with the Lindemann rule applied to short hydrocarbon chains.

An Enormous Compensatory Hyperinflated Lung After Pneumonectomy: Pseudo-horseshoe Lung

Pneumonectomy causes a number of anatomical changes within the thoracic cavity to improve the diffusion capacity of the remaining lung. A 41-year-old female was admitted with the complaints of cough and purulent sputum for the last two weeks. Her past medical history revealed that she underwent left pneumonectomy for bronchiectasis at the age of 10 due to massive hemoptysis. Massive compensatory hyperinflation of the right lung, which was herniated anteriorly across the midline, and extreme mediastinal shift were observed in computed tomography which is called pseudo-horseshoe lung. Although post-pneumonectomy lung compensation can diminish by advanced age, clinicians should be aware that it can be observed in adult patients who had pneumonectomy at early ages.

Extreme evolutionary shifts in developmental timing establish the miniature Danionella as a novel model in the neurosciences

AbstractBackgroundSpecies of Danionella rank among the smallest of all vertebrates and their miniature size is correlated with an extreme case of progenesis, resulting in tiny, transparent sexually mature individuals. Progenesis has affected the entire skeleton of Danionella, in which 60 skeletal elements are absent, including some of the skull roofing bones. This lack of a skull roof combined with the presence of a fully formed hearing and sound producing apparatus has led to Danionella being used as an important model for neurophysiological studies.ResultsUsing both rank based and PGi analyses we investigate sequence heterochrony in the development of the skeleton of Danionella dracula and close relatives. Extreme heterochronic shifts affect the appearance of bony elements in Danionella dracula. This includes a delay in the appearance of most chondral skull bones, and a reduction or loss of dermal bones that would otherwise form the skull roof. In contrast, formation of the anterior region of the vertebral column, including the functionally important elements of the Weberian apparatus, is greatly accelerated.ConclusionsHere we show that the anatomical conditions that favor Danionella for brain research are the result of extreme heterochronic shifts that have acted differentially across the skeleton.

Regime Shifts in an Early Triassic Subtropical Ecosystem

The Early Triassic was one of the most remarkable time intervals in Earth History. To begin with, life on Earth had to face one of the largest subaerial volcanic degassing, the Siberian Traps, followed by a plethora of accompanying environmental hazards with pronounced and repeated climatic changes. These changes not only led to repeated and, for several marine nektonic clades, intense extinction events but also to significant changes in terrestrial ecosystems. The Early Triassic terrestrial ecosystems of the southern subtropical region (Pakistan) are not necessarily marked by abrupt extinction events but by extreme shifts in composition. Modern ecological theories describe such shifts as catastrophic regime shifts. Here, the applicability of modern ecological theories to these past events is tested. Abrupt shifts in ecosystems can occur when protracted changing abiotic drivers (e.g. climate) reach critical points (thresholds or tipping points) sometimes accentuated by stochastic events. Early Triassic terrestrial plant ecosystem changes stand out from the longer term paleobotanical records because changes of similar magnitude have not been observed for many millions of years before and after the Early Triassic. To date, these changes have been attributed to repeated severe environmental perturbations, but here an alternative explanation is tested: the initial environmental perturbations around the Permian–Triassic boundary interval are regarded here as a main cause for a massive loss in terrestrial ecosystem resilience with the effect that comparatively small-scale perturbations in the following ∼5 Ma lead to abrupt regime shifts in terrestrial ecosystems.

Seasonal temperature and rainfall extremes 1911–2017 for Northern Australian population centres: challenges for human activity

More than 40% of the human population reside in global tropical zones despite the extreme climates that frequently approach the upper thermotolerance levels for human physical activity and societal flourishing. Many of these regions also regularly subject resident populations to extreme weather events. Australia’s tropical regions experience exceptionally high climatic variability, making it one of the world’s most challenging for human settlements. Adaptation planning, project management and health protection agencies working at local scales require localized analysis on long-term climatic trends and projections. Utility of existing large-scale analyses is constrained by climatic heterogeneity across expansive national scales. Here we track historical changes in seasonal climatic extremes for seven key population centres across Australia’s north between the periods 1911–1940 and 1988–2017 as measured against the 1961–1990 period. Shifts in daily minimum temperature (20 °C or more), maximum temperature (10th, 90th and 95th percentiles), trends in heatwaves (5 days or longer) and in 1- and 3-day heavy rainfall events (95th and 98th percentiles) are provided. Results indicate the greatest warming has occurred during the Dry season and in coastal locations. Rainfall extremes demonstrate a pattern of marked spatial non-uniformity. This location-centred approach to identifying shifts in climatic extremes has wide applicability for adaptation planning across diverse global climatic regions.

Structural analysis of a new carotenoid-binding protein: the C-terminal domain homolog of the OCP

The Orange Carotenoid Protein (OCP) is a water-soluble protein that governs photoprotection in many cyanobacteria. The 35 kDa OCP is structurally and functionally modular, consisting of an N-terminal effector domain (NTD) and a C-terminal regulatory domain (CTD); a carotenoid spans the two domains. The CTD is a member of the ubiquitous Nuclear Transport Factor-2 (NTF2) superfamily (pfam02136). With the increasing availability of cyanobacterial genomes, bioinformatic analysis has revealed the existence of a new family of proteins, homologs to the CTD, the C-terminal domain-like carotenoid proteins (CCPs). Here we purify holo-CCP2 directly from cyanobacteria and establish that it natively binds canthaxanthin (CAN). We use small-angle X-ray scattering (SAXS) to characterize the structure of this carotenoprotein in two distinct oligomeric states. A single carotenoid molecule spans the two CCPs in the dimer. Our analysis with X-ray footprinting-mass spectrometry (XFMS) identifies critical residues for carotenoid binding that likely contribute to the extreme red shift (ca. 80 nm) of the absorption maximum of the carotenoid bound by the CCP2 dimer and a further 10 nm shift in the tetramer form. These data provide the first structural description of carotenoid binding by a protein consisting of only an NTF2 domain.

Manufacturing in the Time of COVID-19: An Assessment of Barriers and Enablers

Pandemics and other forms of epidemic outbreaks are a unique case of manufacturing risk typified by high uncertainty, increasing propagation, and long-term disruption to manufacturers, supply chain actors as well as the end-users and consumers. For manufacturing the COVID-19 disruption scope has been largely twofold; an endogenous disruption of manufacturing processes and systems as well as extreme shifts in demand and supply caused by exogenous supply chain disruption. Existing literature on disruptions in manufacturing suggests that pandemics are qualitatively different from typical disruptions. There is no literature available to manufacturing practitioners that identify the barriers and enablers of manufacturing resilience, especially with regards to pivoting of the manufacturing sector in response to a pandemic. This article draws on an extensive survey collected during the COVID-19 pandemic. The respondents were employees of manufacturing firms in all regions of the world who had engaged in manufacturing during the pandemic or had opted out from manufacturing due to various identified reasons. By collating their responses, we offer to practitioners and policymakers an analysis for identifying a best-practice framework for pivoting successfully as a response to major manufacturing disruptions.

The degree of spatial variation relative to temporal variation influences evolution of dispersal

In the face of ongoing global climate and land use change, organisms have multiple possibilities to cope with the modification of their environment. The two main possibilities are to either adapt locally or disperse to a more suitable habitat. The evolution of both local adaptation and dispersal interacts and can be influenced by the spatial and temporal variation (of e.g. temperature or precipitation). In an individual based model (IBM), we explore evolution of phenotypes in landscapes with varying degree of spatial relative to global temporal variation in order to examine its influence on the evolution of dispersal, niche optimum and niche width. The relationship between temporal and spatial variation did neither influence the evolution of local adaptation in the niche optimum nor of niche widths. Dispersal probability is highly influenced by the spatio‐temporal relationship: with increasing spatial variation, dispersal probability decreases. Additionally, the shape of the distribution of the trait values over patch attributes switches from hump‐ to U‐shaped. At low spatial variance more individuals emigrate from average habitats, at high spatial variance more from extreme habitats. The comparatively high dispersal probability in extreme patches of landscapes with a high spatial variation can be explained by evolutionary succession of two kinds of adaptive response. Early in the simulations, extreme patches in landscapes with a high spatial variability act as sink habitats, where population persistence depends on highly dispersive individuals with a wide niche. With ongoing evolution, local adaptation of the remaining individuals takes over, but simultaneously a possible bet‐hedging strategy promotes higher dispersal probabilities in those habitats. Here, in generations that experience extreme shifts from the temporal mean of the patch attribute, the expected fitness becomes higher for dispersing individuals than for philopatric individuals. This means that under certain circumstances, both local adaptation and high dispersal probability can be selected for for coping with the projected environmental changes in the future.

Abstract 466: Epigenetic drug profiling in diffuse intrinsic pontine glioma

Abstract Diffuse Intrinsic Pontine Glioma (DIPG) is a highly aggressive and universally fatal form of childhood brain cancer. As prognosis has improved little over the last 40 years, exploring alternate drug therapies remains paramount. Roughly 80% of DIPG patients harbor mutations that result in the substitution of a lysine for a methionine at position 27 of histone variants 3.1 and 3.3 (H3.1K27M and H3.3K27M). This hallmark mutation causes global epigenetic changes in DIPG patients by dysregulating methylation and acetylation of histones, thus making the epigenome a potential therapeutic target. We explored vulnerabilities in 10 DIPG models (8 of which were H3.3K27M and 2 of which were H3.1K27M) to HDAC inhibitors (TSA and Panobinostat) and an LSD1 inhibitor (SP2577) both alone and in combination using drug dose response assays. As expected, Panobinostat showed high potency in each DIPG cell line, with 7 of the 9 lines having IC50 values less than 10 nM. In contrast, all 10 lines had no response to SP2577 apart from cytotoxic reactions in higher concentration ranges. SP2577 will thus be interesting to test in combination with Panobinostat with the intention of increasing its sensitivity. We also evaluated the efficacy of epigenetic drugs when used in combination with drugs targeting transcriptional pathways including TGN1076, a novel reversible CDK7 inhibitor. We found that TGN1076 shows marginal synergy with TSA, an HDAC inhibitor, and good synergy with JQ1, a BET inhibitor in the cell line DIPG6. Though equilibrating the epigenome remains a necessary objective in DIPG research, elucidating the mechanisms underlying extreme epigenetic shifts could provide important insight into disease pathogenesis. For this reason, we also focused on the histone methyltransferase protein PRC2 which is commonly implicated in epigenetic dysregulation in DIPG. Because the catalytic subunit of PRC2, EZH1/2, is allosterically regulated by another subunit, EED, in a “write and read mechanism,” we are testing the efficacy of the drug EED226 which binds to EED and modulates the function of PRC2. Analyzing the effects of this drug alone and in combination will provide a novel approach to managing PRC2 dysregulation and will potentially reveal future therapeutic strategies. Through screening novel drugs and testing their efficacies in combination with drugs that are commercially available, we intend to provide future therapeutic options for DIPG patients. Citation Format: Hannah Tolson. Epigenetic drug profiling in diffuse intrinsic pontine glioma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 466.

Storing fish?: a dog\u2019s isotopic biography provides insight into Iron Age food preservation strategies in the Russian Arctic

Analysis of individual animal bodies can provide numerous useful insights in archeology, including how humans provisioned such animals, which in turn informs on a variety of other past behaviors such as human dietary patterns. In this study, we conducted stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of collagen and keratin from four types of tissues from a dog burial at the Ust’-Polui site in the Iamal region of Arctic Russia. Ust’-Polui is an Iron Age site located on the Lower Ob River, a major northern fishery characterized by extreme seasonal shifts in fish presence. During a 6-month period stretching over the coldest months of the year, fish are nearly entirely absent in the Lower Ob River. Despite this, the stable isotope compositions of the dog’s bone and dentine collagen and hair and nail keratin all indicate a monotonous diet focusing on local fish. This pattern indicates the dog was provisioned year-round with fish. This was likely accomplished by mass harvesting of fish using nets or traps. Such fish were then processed and frozen for consumption during the non-fishing season. These findings suggest that people in the Ust’-Polui region also relied to some extent on fish throughout the year. Stored fish likely provided a dietary buffer for uneven returns from reindeer and bird hunting, both of which also are well-evidenced at the site.

On the Theory of Positional Differential Games for Neutral-Type Systems

For a dynamical system whose motion is described by neutral-type differential equations in Hale’s form, we consider a minimax–maximin differential game with a quality index evaluating the motion history realized up to the terminal time. The control actions of the players are subject to geometric constraints. The game is formalized in classes of pure positional strategies with a memory of the motion history. It is proved that the game has a value and a saddle point. The proof is based on the choice of an appropriate Lyapunov–Krasovskii functional for the construction of control strategies by the method of an extremal shift to accompanying points.

Extreme warming and regime shift toward amplified variability in a far northern lake

AbstractMean annual air temperatures in the High Arctic are rising rapidly, with extreme warming events becoming increasingly common. Little is known, however, about the consequences of such events on the ice‐capped lakes that occur abundantly across this region. Here, we compared 2 years of high‐frequency monitoring data in Ward Hunt Lake in the Canadian High Arctic. One of the years included a period of anomalously warm conditions that allowed us to address the question of how loss of multi‐year ice cover affects the limnological properties of polar lakes. A mooring installed at the deepest point of the lake (9.7 m) recorded temperature, oxygen, chlorophyll a (Chl a) fluorescence, and underwater irradiance from July 2016 to July 2018, and an automated camera documented changes in ice cover. The complete loss of ice cover in summer 2016 resulted in full wind exposure and complete mixing of the water column. This mixing caused ventilation of lake water heat to the atmosphere and 4°C lower water temperatures than under ice‐covered conditions. There were also high values of Chl a fluorescence, elevated turbidity levels and large oxygen fluctuations throughout fall and winter. During the subsequent summer, the lake retained its ice cover and the water column remained stratified, with lower Chl a fluorescence and anoxic bottom waters. Extreme warming events are likely to shift polar lakes that were formerly capped by continuous thick ice to a regime of irregular ice loss and unstable limnological conditions that vary greatly from year to year.

Defensive manoeuvres of NHX1 and SOS1 co/overexpression in plant salt tolerance

Excessive accumulation of salts is one of the most important factors affecting the production quality of plants. The difficulty to develop salt stress tolerant crops has prevented the security of the global food system. The classical crop breeding approach that uses random mutagenesis/recombination is time-consuming in the face of an ever-increasing human population and extreme weather pattern shifts. Today, technologies introducing foreign genetic material into plants have the best potential to assist in crop breeding improvement due to its high efficiency, accuracy, low risk of off-target effects, and minimal labour compared to classical methods. The notion of Na+/H+ antiporters in this technology has increased rapidly in recent years with numerous successful examples. In the awe of rapidly developing modern techniques, which do not yet exist at the required scale to face the aforementioned challenges, the current knowledge of the co/overexpressing Na+/H+ antiporters NHX1 and SOS1 will be explored as a potential method to produce staple crops with greater resilience to over concentrated ions and abnormally high osmotic stress.