This paper presents a fast algorithm for restoring video sequences. The proposed algorithm, as opposed to existing methods, does not consider video restoration as a sequence of image restoration ...problems. Rather, it treats a video sequence as a space-time volume and poses a space-time total variation regularization to enhance the smoothness of the solution. The optimization problem is solved by transforming the original unconstrained minimization problem to an equivalent constrained minimization problem. An augmented Lagrangian method is used to handle the constraints, and an alternating direction method is used to iteratively find solutions to the subproblems. The proposed algorithm has a wide range of applications, including video deblurring and denoising, video disparity refinement, and hot-air turbulence effect reduction.
The Paris Agreement calls for global warming to be limited to 1.5-2 °C. For the first time, this study investigates how different regional heatwave characteristics (intensity, frequency and duration) ...are projected to change relative to increasing global warming thresholds. Increases in heatwave days between 4-34 extra days per season are projected per °C of global warming. Some tropical regions could experience up to 120 extra heatwave days/season if 5 °C is reached. Increases in heatwave intensity are generally 0.5-1.5 °C above a given global warming threshold, however are higher over the Mediterranean and Central Asian regions. Between warming thresholds of 1.5 °C and 2.5 °C, the return intervals of intense heatwaves reduce by 2-3 fold. Heatwave duration is projected to increase by 2-10 days/°C, with larger changes over lower latitudes. Analysis of two climate model ensembles indicate that variation in the rate of heatwave changes is dependent on physical differences between different climate models, however internal climate variability bears considerable influence on the expected range of regional heatwave changes per warming threshold. The results of this study reiterate the potential for disastrous consequences associated with regional heatwaves if global mean warming is not limited to 2 degrees.
Employees often self-initiate changes to their jobs, a process referred to as job crafting, yet we know little about why and how they initiate such changes. In this paper, we introduce and test an ...extended framework for job crafting, incorporating individuals' needs and regulatory focus. Our theoretical model posits that individual needs provide employees with the motivation to engage in distinct job-crafting strategies-task, relationship, skill, and cognitive crafting-and that work-related regulatory focus will be associated with promotion- or prevention-oriented forms of these strategies. Across three independent studies and using distinct research designs (Study 1: N = 421 employees; Study 2: N = 144, using experience sampling data; Study 3: N = 388, using a lagged study design), our findings suggest that distinct job-crafting strategies, and their promotion- and prevention-oriented forms, can be meaningfully distinguished and that individual needs (for autonomy, competence, and relatedness) at work differentially shape job-crafting strategies. We also find that promotion- and prevention-oriented forms of job-crafting vary in their relationship with innovative work performance, and we find partial support for work-related regulatory focus strengthening the indirect effect of individual needs on innovative work performance via corresponding forms of job crafting. Our findings suggest that both individual needs and work-related regulatory focus are related to why and how employees will choose to craft their jobs, as well as to the consequences job crafting will have in organizations.
Our 2006 Journal of International Business Studies article, "A Quarter Century of Culture's Consequences: A Review of the Empirical Research Incorporating Hofstede's Cultural Values Framework," ...provided a comprehensive review of 180 empirical journal articles and edited volume chapters published between 1980 and June 2002 that incorporated Hofstede's cross-cultural values framework. We examined empirical research that positioned culture as either a main or moderating effect. The review attempted to make sense of the almost quarter century of research examining the impact of culture at the individual, group/organization, and country levels. In the present commentary, we provide: (a) a summary of the progress that has been made in the intervening decade, and most importantly, (b) a new set of recommendations for the next decade to guide those wishing to study the role of national culture in organizations.
Ferroptosis is a cell death pathway characterized by iron-dependent accumulation of reactive oxygen species (ROS) within the cell. The combination of siramesine, a lysosome disruptor, and lapatinib, ...a dual tyrosine kinase inhibitor, has been shown to synergistically induce cell death in breast cancer cells mediated by ferroptosis. These treatments also induce autophagy but its role in this synergistic cell death is unclear. In this study, we determined that siramesine and lapatinib initially induced ferroptosis but changes to an autophagy induced cell death after 24 hours. Furthermore, we found that intracellular iron level increased in a time dependent manner following treatment accompanied by an increase in ROS. Using the iron chelator deferoxamine (DFO) or the ROS scavenger alpha-tocopherol decreased both autophagy flux and cell death. We further discovered that decreased expression of the iron storage protein, ferritin was partially dependent upon autophagy degradation. In contrast, the expression of transferrin, which is responsible for the transport of iron into cells, is increased following treatment with lapatinib alone or in combination with siramesine. This indicates that ferroptosis and autophagy induced cell death occur independently but both are mediated by iron dependent ROS generation in breast cancer cells.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We developed a model illuminating team knowledge exchange processes as a key link between organizational diversity climate and the effectiveness of multicultural teams (MCTs). Our analysis is based ...on 143 in-depth interviews and extensive observations of team interactions that occurred in 48 teams from 11 companies. Our findings revealed that teams that oscillated between assertive and cooperative knowledge exchange processes were more effective. We also found such dual processes were more prevalent in organizations that had an engagement-focused diversity climate characterized by utilization of diversity to inform and enhance work processes based on the assumption that cultural differences give rise to different knowledge, insights, and alternative views. Based on our findings we developed specific propositions about optimizing MCT knowledge-exchange processes to guide future research and practice.
Within a fully cosmological hydrodynamical simulation, we form a galaxy which rotates at 140 km s−1, and it is characterized by two loose spiral arms and a bar, indicative of a Hubble-type SBc/d ...galaxy. We show that our simulated galaxy has no classical bulge, with a pure disc profile at z = 1, well after the major merging activity has ended. A long-lived bar subsequently forms, resulting in the formation of a secularly formed 'pseudo-'bulge, with the final bulge-to-total light ratio of 0.21. We show that the majority of gas which loses angular momentum and falls to the central region of the galaxy during the merging epoch is blown back into the hot halo, with much of it returning later to form stars in the disc. We propose that this mechanism of redistribution of angular momentum via a galactic fountain, when coupled with the results from our previous study which showed why gas outflows are biased to have low angular momentum, can solve the angular momentum/bulgeless disc problem of the cold dark matter paradigm.
Starvation is the most extensively studied condition that induces autophagy. Previous studies have demonstrated that starvation-induced autophagy is regulated by reactive oxygen species (ROS) such as ...superoxide (O2−) but the source for ROS under starvation conditions and the downstream signaling pathways regulating autophagy are unclear. In this study, a cervical cancer HeLa cell line was generated that was deficient in mitochondrial electron transport chain (mETC) (HeLa ρ° cells). This resulted in endogenous levels of O2− being significantly reduced and failed to be induced under starvation of glucose, L-glutamine, pyruvate, and serum (GP) or of amino acids and serum (AA) compared to wild type (wt) HeLa cells. In contrast, H2O2 production failed to increase under GP starvation in both wild type and ρ° cells whereas it increased in wt cells but not in ρ° cells under AA starvation. GP or AA starvation induced autophagy was blocked in ρ° cells as determined by the amount of autophagosomes and autolysosomes. Autophagy is regulated by 5′ adenosine monophosphate-activated protein kinase (AMPK) activation and AMPK is activated under starvation conditions. We demonstrate that ρ° cells and HeLa cells over expressing manganese-superoxide dismutase 2 (SOD2) cells fail to activate AMPK activation following starvation. This indicates that mitochondrial ROS might regulate AMPK activation. In addition, inhibiting AMPK activation either by siRNA or compound C resulted in reduced autophagy during starvation. Using a ROS scavenger NAC, AMPK activation is reduced under starvation condition and mTOR signaling is increased. Taken together, mitochondria-generated ROS induces autophagy mediated by the AMPK pathway under starvation conditions.
► Reactive oxygen species (ROS) induces autophagy. ► Mitochondrial generated ROS mediates starvation induced autophagy. ► ROS induces autophagy through activation of AMPK. ► ROS regulates the AMPK/mTOR pathway.
Ferroptosis is an iron-dependent, oxidative cell death, and is distinct from apoptosis, necrosis and autophagy. In this study, we demonstrated that lysosome disrupting agent, siramesine and a ...tyrosine kinase inhibitor, lapatinib synergistically induced cell death and reactive oxygen species (ROS) in MDA MB 231, MCF-7, ZR-75 and SKBr3 breast cancer cells over a 24 h time course. Furthermore, the iron chelator deferoxamine (DFO) significantly reduced cytosolic ROS and cell death following treatment with siramesine and lapatinib. Furthermore, we determined that FeCl3 levels were elevated in cells treated with siramesine and lapatinib indicating an iron-dependent cell death, ferroptosis. To confirm this, we treated cells with a potent inhibitor of ferroptosis, ferrastatin-1 that effectively inhibited cell death following siramesine and lapatinib treatment. The increase levels of iron could be due to changes in iron transport. We found that the expression of transferrin, which is responsible for the transport of iron into cells, is increased following treatment with lapatinib alone or in combination with siramesine. Knocking down of transferrin resulted in decreased cell death and ROS after treatment. In addition, ferroportin-1 (FPN) is an iron transport protein, responsible for removal of iron from cells. We found its expression is decreased after treatment with siramesine alone or in combination with lapatinib. Overexpression FPN resulted in decreased ROS and cell death whereas knockdown of FPN increased cell death after siramesine and lapatinib treatment. This indicates a novel induction of ferroptosis through altered iron regulation by treating breast cancer cells with a lysosome disruptor and a tyrosine kinase inhibitor.
This paper makes an investigation of the dehazing effects on image and video coding for surveillance systems. The goal is to achieve good dehazed images and videos at the receiver while sustaining ...low bitrates (using compression) in the transmission pipeline. At first, this paper proposes a novel method for single-image dehazing, which is used for the investigation. It operates at a faster speed than current methods and can avoid halo effects by using the median operation. We then consider the dehazing effects in compression by investigating the coding artifacts and motion estimation in cases of applying any dehazing method before or after compression. We conclude that better dehazing performance with fewer artifacts and better coding efficiency is achieved when the dehazing is applied before compression. Simulations for Joint Photographers Expert Group images in addition to subjective and objective tests with H.264 compressed sequences validate our conclusion.
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