Ferroptosis is a novel form of programmed cell death in which the accumulation of intracellular iron promotes lipid peroxidation, leading to cell death. Recently, the induction of autophagy has been ...suggested during ferroptosis. However, this relationship between autophagy and ferroptosis is still controversial and the autophagy-inducing mediator remains unknown. In this study, we confirmed that autophagy is indeed induced by the ferroptosis inducer erastin. Furthermore, we show that autophagy leads to iron-dependent ferroptosis by degradation of ferritin and induction of transferrin receptor 1 (TfR1) expression, using wild-type and autophagy-deficient cells, BECN1
and LC3B
. Consistently, autophagy deficiency caused depletion of intracellular iron and reduced lipid peroxidation, resulting in cell survival during erastin-induced ferroptosis. We further identified that autophagy was triggered by erastin-induced reactive oxygen species (ROS) in ferroptosis. These data provide evidence that ROS-induced autophagy is a key regulator of ferritin degradation and TfR1 expression during ferroptosis. Our study thus contributes toward our understanding of the ferroptotic processes and also helps resolve some of the controversies associated with this phenomenon.
Retail inventory shrinkage, resulting primarily from employee theft and shoplifting, costs retailers nearly $70 billion annually. With brick‐and‐mortar retailers today confronting increased ...competition and low future growth expectations, reducing inventory shrinkage is becoming even more critical to becoming profitable. This paper analyzes a unique dataset that combines both primary survey and objective archival data from a Fortune 500 retailer to test a theoretical model associating retail inventory shrinkage, the capacity of a retail store to sense weak security breach signals, centralization of decision making, and formalization of security breach management. The analysis builds on insights from high reliability organization theory and the literature on organizational structure. Results reveal that as a retail store increases its capacity to sense weak security breach signals, it observes decreases in store‐level inventory shrinkage, with this negative association amplified (dampened) when the retail store has formalized procedures and protocols for managing security breaches (has centralized decision making within the retail store). Moreover, while the establishment of formalized procedures and protocols for managing security breaches bolsters the capacity of a retail store to sense weak security breach signals, centralizing decision making has the opposite effect. Our findings contribute to the retail operations literature by introducing a new store‐level organizational capability to guard against theft‐based retail inventory shrinkage and by offering novel insights into how and why organizational structure at the level of a retail store deters or facilitates the capacity to sense weak security breach signals. From a practical perspective, these findings advise retailers to develop the capability to become aware of and to mitigate security breaches. Further, to support this capacity, retailers are urged to decentralize decision making to retail store personnel and to invest in formalizing procedures and protocols for managing security breaches in order to deter retail thefts that shrink retail store inventory.
Recently, a new seeding growth approach for perovskite thin films is reported to significantly enhance the device performance of perovskite solar cells. This work unveils the intermediate structures ...and the corresponding growth kinetics during conversion to perovskite crystal thin films assisted by seeding PbS nanocrystals (NCs), using time‐resolved grazing‐incidence X‐ray scattering. Through analyses of time‐resolved crystal formation kinetics obtained from synchrotron X‐rays with a fast subsecond probing time resolution, an important “catalytic” role of the seed‐like PbS NCs is clearly elucidated. The perovskite precursor‐capped PbS NCs are found to not only accelerate the nucleation of a highly oriented intermediate phase, but also catalyze the conversion of the intermediate phase into perovskite crystals with a reduced activation energy Ea = 47 (±5) kJ mol−1, compared to 145 (±38) kJ mol−1 for the pristine perovskite thin film. The reduced Ea is attributed to a designated crystal lattice alignment of the perovskite nanocrystals with perovskite cubic crystals; the pivotal heterointerface alignment of the perovskite crystals coordinated by the Pb NCs leads to an improved film surface morphology with less pinholes and enhanced crystal texture and thermal stability. These together contribute to the significantly improved photovoltaic performance of the corresponding devices.
Time‐resolved grazing‐incidence X‐ray scattering reveals cascade effects of PbS nanocrystals seeded in perovskite thin films. During annealing, PbS nanocrystals accelerate the nucleation of a highly oriented intermediate phase L1 through capped organic perovskite precursors, and subsequently catalyze the L1‐to‐perovskite conversion via lattice anchoring alignment with the cubic lattice of the perovskite, leading to improved crystal grain connectivity, texture, and thermal stability.
Past research has proven the significant effects of game-based learning on learning motivation and academic performance, and described the key factors in game-based design. Nonetheless, research on ...the correlations among learning motivation, cognitive load, learning anxiety and academic performance in gamified learning environments has been minimal. This study, therefore, aims to develop a Gamification Software Engineering Education Learning System (GSEELS) and evaluate the effects of gamification, learning motivation, cognitive load and learning anxiety on academic performance. By applying Structural Equation Modeling (SEM) to the empirical research, the questionnaire contains: 1. a Gamification Learning Scale; 2. a Learning Motivation Scale; 3. a Cognitive Load Scale; 4. a Learning Anxiety Scale; and 5. an Academic Performance Scale. A total of 107 undergraduates in two classes participated in this study. The Structural Equation Modeling (SEM) analysis includes the path directions and relationship between descriptive statistics, measurement model, structural model evaluation and five variables. The research results support all nine hypotheses, and the research findings also show the effects of cognitive load on learning anxiety, with strong learning motivation resulting from a low learning anxiety. As a result, it is further proven in this study that a well-designed GSEELS would affect student learning motivation and academic performance. Finally, the relationship model between gamification learning, learning motivation, cognitive load, learning anxiety and academic performance is elucidated, and four suggestions are proffered for instructors of software engineering education courses and for further research, so as to assist instructors in the application of favorable gamification teaching strategies.
The problem of output feedback sliding mode control for sampled-data systems in the presence of external disturbances is considered. The proposed output feedback control strategy helps obtain a quasi ...sliding mode with an O(T 3 ) boundary layer, where T is the sampling period. This outperforms the O(T 2 ) result induced by the one-step delayed disturbance approximation method. The proposed scheme is applicable to linear systems which are relative degree one and minimum phase. An example is given to illustrate the efficacy of the new method.
In animal cells, formation of the cytokinetic furrow requires activation of the GTPase RhoA by the guanine nucleotide exchange factor Ect2. How Ect2, which is associated with the spindle midzone, ...controls RhoA activity at the equatorial cortex during anaphase is not understood. Here, we show that Ect2 concentrates at the equatorial membrane during cytokinesis in live cells. Ect2 membrane association requires a pleckstrin homology domain and a polybasic cluster that bind to phosphoinositide lipids. Both guanine nucleotide exchange function and membrane targeting of Ect2 are essential for RhoA activation and cleavage furrow formation in human cells. Membrane localization of Ect2 is spatially confined to the equator by centralspindlin, Ect2's spindle midzone anchor complex, and is temporally coordinated with chromosome segregation through the activation state of CDK1. We propose that targeting of Ect2 to the equatorial membrane represents a key step in the delivery of the cytokinetic signal to the cortex.
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► Live-cell imaging reveals equatorial membrane localization of Ect2 at cytokinesis ► Membrane association of Ect2 requires a pleckstrin domain and polybasic cluster ► GEF activity and membrane targeting of Ect2 control cleavage furrow formation ► Central spindlin and CDK1 activity control Ect2 membrane targeting in space and time
Secondary exposure to e‐cigarette aerosol (passive vaping) will soon become a pressing public health issue in the world. Yet, the current knowledge about respiratory depositions of e‐cigarette ...aerosol through passive vaping in human airways is limited due to critical weaknesses of traditional experimental methods. To fill in this important knowledge gap, this study proposed a special approach involving an upgraded Mobile Aerosol Lung Deposition Apparatus (MALDA) that consists of a set of human airway replicas including a head airway, tracheobronchial airways down to the 11th lung generation, and a representative alveolar section. In addition to the comprehensive coverage of human airways, the MALDA is easily transportable for providing efficient estimations of aerosol respiratory deposition. In this study, the MALDA was first evaluated in the laboratory and then applied to estimate the respiratory deposition associated with passive vaping in an indoor real‐life setting. The results showed that the respiratory deposition data aligned closely with the conventional respiratory deposition curves not only in the head‐to‐TB region but also in the alveolar region. The strengths of MALDA demonstrate great promise for a wide variety of applications in real‐life settings that could provide crucial information for future public health and indoor air quality studies.
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