The Potential of the Synthetic Strigolactone Analogue GR24 for the Maintenance of Photosynthesis and Yield in Winter Wheat under Drought: Investigations on the Mechanisms of Action and Delivery Modes

Strigolactones (SLs) have been implicated in many plant biological and physiological processes, including the responses to abiotic stresses such as drought, in concert with other phytohormones. While it is now clear that exogenous SLs may help plants to survive in harsh environmental condition, the best, most effective protocols for treatment have not been defined yet, and the mechanisms of action are far from being fully understood. In the set of experiments reported here, we contrasted two application methods for treatment with a synthetic analog of SL, GR24. A number of morphometric, physiological and biochemical parameters were measured following foliar application of GR24 or application in the residual irrigation water in winter wheat plants under irrigated and drought stress conditions. Depending on the concentration and the method of GR24 application, differentiated photosynthesis and transpiration rate, stomatal conductance, leaf water potential, antioxidant enzyme activities and yield in drought conditions were observed. We present evidence that different methods of GR24 application led to increased photosynthesis and yield under stress by a combination of drought tolerance and escape factors, which should be considered for future research exploring the potential of this new family of bioactive molecules for practical applications.

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Propolis Extract and Its Bioactive Compounds—From Traditional to Modern Extraction Technologies

Molecules ◽

10.3390/molecules26102930 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2930

Author(s):

Jelena Šuran ◽

Ivica Cepanec ◽

Tomislav Mašek ◽

Božo Radić ◽

Saša Radić ◽

...

Keyword(s):

Antimicrobial Activity ◽

Geographical Origin ◽

Research Area ◽

Mechanisms Of Action ◽

Bioactive Molecules ◽

Erk Pathway ◽

Pharmacological Effects ◽

Propolis Extract ◽

Open Research ◽

Antioxidant Mechanisms

Propolis is a honeybee product known for its antioxidant, anti-inflammatory, anticancer, and antimicrobial effects. It is rich in bioactive molecules whose content varies depending on the botanical and geographical origin of propolis. These bioactive molecules have been studied individually and as a part of propolis extracts, as they can be used as representative markers for propolis standardization. Here, we compare the pharmacological effects of representative polyphenols and whole propolis extracts. Based on the literature data, polyphenols and extracts act by suppressing similar targets, from pro-inflammatory TNF/NF-κB to the pro-proliferative MAPK/ERK pathway. In addition, they activate similar antioxidant mechanisms of action, like Nrf2-ARE intracellular antioxidant pathway, and they all have antimicrobial activity. These similarities do not imply that we should attribute the action of propolis solely to the most representative compounds. Moreover, its pharmacological effects will depend on the efficacy of these compounds’ extraction. Thus, we also give an overview of different propolis extraction technologies, from traditional to modern ones, which are environmentally friendlier. These technologies belong to an open research area that needs further effective solutions in terms of well-standardized liquid and solid extracts, which would be reliable in their pharmacological effects, environmentally friendly, and sustainable for production.

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A Survey on Deep Learning Based Methods and Datasets for Monocular 3D Object Detection

Electronics ◽

10.3390/electronics10040517 ◽

2021 ◽

Vol 10 (4) ◽

pp. 517

Author(s):

Seong-heum Kim ◽

Youngbae Hwang

Keyword(s):

Deep Learning ◽

Object Detection ◽

Low Cost ◽

Detection Methods ◽

Future Research ◽

3D Object ◽

Practical Applications ◽

Depth Sensors ◽

Significant Research ◽

3D Object Detection

Owing to recent advancements in deep learning methods and relevant databases, it is becoming increasingly easier to recognize 3D objects using only RGB images from single viewpoints. This study investigates the major breakthroughs and current progress in deep learning-based monocular 3D object detection. For relatively low-cost data acquisition systems without depth sensors or cameras at multiple viewpoints, we first consider existing databases with 2D RGB photos and their relevant attributes. Based on this simple sensor modality for practical applications, deep learning-based monocular 3D object detection methods that overcome significant research challenges are categorized and summarized. We present the key concepts and detailed descriptions of representative single-stage and multiple-stage detection solutions. In addition, we discuss the effectiveness of the detection models on their baseline benchmarks. Finally, we explore several directions for future research on monocular 3D object detection.

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The Bioactive Potential of Trawl Discard: Case Study from a Crinoid Bed Off Blanes (North-Western Mediterranean)

Marine Drugs ◽

10.3390/md19020083 ◽

2021 ◽

Vol 19 (2) ◽

pp. 83

Author(s):

Alfredo García-de-Vinuesa ◽

Montserrat Demestre ◽

Arnau Carreño ◽

Josep Lloret

Keyword(s):

Bioactive Compounds ◽

Fish Habitat ◽

Antibacterial Properties ◽

Marine Species ◽

Western Mediterranean ◽

Bioactive Molecules ◽

Added Value ◽

Future Research ◽

Trawl Survey ◽

Bioactive Potential

Although knowledge of the bioactive compounds produced by species inhabiting coastal waters is increasing, little is known about the bioactive potential produced by marine species occupying deeper habitats with high biodiversity and productivity. Here, we investigate about the bioactive potential of molecules produced by species that inhabit the crinoid beds, a poorly known essential fish habitat affected by trawling, wherein large amounts of commercial and noncommercial species are discarded. Based on a trawl survey conducted in 2019, 14% of the 64 species discarded on crinoid beds produce molecules with some type of bioactive potential, including; soft corals (Alcyonium palmatum); tunicates (Ascidia mentula); bony fish, such as horse mackerel (Trachurus trachurus); European hake (Merluccius merluccius); and chondrichthyans, such as small-spotted catshark (Scyliorhinus canicula). In addition, 16% of the discarded species had congeneric species that produce compounds with bioactive potential, indicating that such species might also possess similar types of bioactive molecules. Molecules with antioxidant, antitumour, antihypertensive, and antibacterial properties were the most frequent, which could provide the basis for future research aiming to discover new marine-based drugs and compounds for other human uses. Among all species or genera that produce compounds with bioactive potential, 68% presented medium or high vulnerability to trawling. Results show that the discarded catch contains many species, which produce different bioactive compounds that represent an added-value resource. These results highlight the importance of manage properly crinoid beds, to ensure that species that produce molecules with bioactive potential inhabiting these habitats are protected.

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Plant-Derived Anticancer Compounds as New Perspectives in Drug Discovery and Alternative Therapy

Molecules ◽

10.3390/molecules26041109 ◽

2021 ◽

Vol 26 (4) ◽

pp. 1109

Author(s):

Cristina Adriana Dehelean ◽

Iasmina Marcovici ◽

Codruta Soica ◽

Marius Mioc ◽

Dorina Coricovac ◽

...

Keyword(s):

Targeted Delivery ◽

Alternative Therapy ◽

Natural Compounds ◽

Mechanisms Of Action ◽

Chemotherapeutic Agents ◽

Biologically Active ◽

Bioactive Molecules ◽

Multi Drug Resistance ◽

Chemopreventive Agents ◽

Pharmaceutical Agents

Despite the recent advances in the field of chemically synthetized pharmaceutical agents, nature remains the main supplier of bioactive molecules. The research of natural products is a valuable approach for the discovery and development of novel biologically active compounds possessing unique structures and mechanisms of action. Although their use belongs to the traditional treatment regimes, plant-derived compounds still cover a large portion of the current-day pharmaceutical agents. Their medical importance is well recognized in the field of oncology, especially as an alternative to the limitations of conventional chemotherapy (severe side effects and inefficacy due to the occurrence of multi-drug resistance). This review offers a comprehensive perspective of the first blockbuster chemotherapeutic agents of natural origin’s (e.g. taxol, vincristine, doxorubicin) mechanism of action using 3D representation. In addition is portrayed the step-by-step evolution from preclinical to clinical evaluation of the most recently studied natural compounds with potent antitumor activity (e.g. resveratrol, curcumin, betulinic acid, etc.) in terms of anticancer mechanisms of action and the possible indications as chemotherapeutic or chemopreventive agents and sensitizers. Finally, this review describes several efficient platforms for the encapsulation and targeted delivery of natural compounds in cancer treatment

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Distributed Ledger Technology Applications in Food Supply Chains: A Review of Challenges and Future Research Directions

Sustainability ◽

10.3390/su13084206 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4206

Author(s):

Jamilya Nurgazina ◽

Udsanee Pakdeetrakulwong ◽

Thomas Moser ◽

Gerald Reiner

Keyword(s):

Supply Chains ◽

Food Supply ◽

Information Exchange ◽

Security And Privacy ◽

Future Research ◽

Research Directions ◽

Practical Applications ◽

Food Supply Chains ◽

Distributed Ledger ◽

Future Research Directions

The lack of transparency and traceability in food supply chains (FSCs) is raising concerns among consumers and stakeholders about food information credibility, food quality, and safety. Insufficient records, a lack of digitalization and standardization of processes, and information exchange are some of the most critical challenges, which can be tackled with disruptive technologies, such as the Internet of Things (IoT), blockchain, and distributed ledger technologies (DLTs). Studies provide evidence that novel technological and sustainable practices in FSCs are necessary. This paper aims to describe current practical applications of DLTs and IoT in FSCs, investigating the challenges of implementation, and potentials for future research directions, thus contributing to achievement of the United Nations’ Sustainable Development Goals (SDGs). Within a systematic literature review, the content of 69 academic publications was analyzed, describing aspects of implementation and measures to address the challenges of scalability, security, and privacy of DLT, and IoT solutions. The challenges of high costs, standardization, regulation, interoperability, and energy consumption of DLT solutions were also classified as highly relevant, but were not widely addressed in literature. The application of DLTs in FSCs can potentially contribute to 6 strategic SDGs, providing synergies and possibilities for more sustainable, traceable, and transparent FSCs.

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Hierarchical Reinforcement Learning

ACM Computing Surveys ◽

10.1145/3453160 ◽

2021 ◽

Vol 54 (5) ◽

pp. 1-35

Author(s):

Shubham Pateria ◽

Budhitama Subagdja ◽

Ah-hwee Tan ◽

Chai Quek

Keyword(s):

Reinforcement Learning ◽

Future Research ◽

Comprehensive Overview ◽

Open Problems ◽

Practical Applications ◽

Hierarchical Reinforcement Learning ◽

The Past ◽

Agent Learning ◽

Multi Agent ◽

Supplementary Material

Hierarchical Reinforcement Learning (HRL) enables autonomous decomposition of challenging long-horizon decision-making tasks into simpler subtasks. During the past years, the landscape of HRL research has grown profoundly, resulting in copious approaches. A comprehensive overview of this vast landscape is necessary to study HRL in an organized manner. We provide a survey of the diverse HRL approaches concerning the challenges of learning hierarchical policies, subtask discovery, transfer learning, and multi-agent learning using HRL. The survey is presented according to a novel taxonomy of the approaches. Based on the survey, a set of important open problems is proposed to motivate the future research in HRL. Furthermore, we outline a few suitable task domains for evaluating the HRL approaches and a few interesting examples of the practical applications of HRL in the Supplementary Material.

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Alleviation of drought stress in winter wheat by late foliar application of zinc, boron, and manganese

Journal of Plant Nutrition and Soil Science ◽

10.1002/jpln.201100141 ◽

2012 ◽

Vol 175 (1) ◽

pp. 142-151 ◽

Cited By ~ 49

Author(s):

Md. Rezaul Karim ◽

Yue-Qiang Zhang ◽

Rong-Rong Zhao ◽

Xin-Ping Chen ◽

Fu-Suo Zhang ◽

...

Keyword(s):

Drought Stress ◽

Winter Wheat ◽

Foliar Application

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Inorganic nanomaterial lubricant additives for base fluids, to improve tribological performance: Recent developments

Friction ◽

10.1007/s40544-021-0511-7 ◽

2021 ◽

Author(s):

Junhai Wang ◽

Weipeng Zhuang ◽

Wenfeng Liang ◽

Tingting Yan ◽

Ting Li ◽

...

Keyword(s):

Metal Oxides ◽

Metallic Nanoparticles ◽

Carbon Nanomaterials ◽

Hexagonal Boron Nitride ◽

Tribological Performance ◽

Inorganic Nanoparticles ◽

Future Research ◽

Graphene Oxides ◽

Practical Applications ◽

Nano Additives

AbstractIn this paper, we review recent research developments regarding the tribological performances of a series of inorganic nano-additives in lubricating fluids. First, we examine several basic types of inorganic nanomaterials, including metallic nanoparticles, metal oxides, carbon nanomaterials, and “other” nanomaterials. More specifically, the metallic nanoparticles we examine include silver, copper, nickel, molybdenum, and tungsten nanoparticles; the metal oxides include CuO, ZnO, Fe3O4, TiO2, ZrO2, Al2O3, and several double-metal oxides; the carbon nanomaterials include fullerene, carbon quantum dots, carbon nanotubes, graphene, graphene oxides, graphite, and diamond; and the “other” nanomaterials include metal sulfides, rare-earth compounds, layered double hydroxides, clay minerals, hexagonal boron nitride, black phosphorus, and nanocomposites. Second, we summarize the lubrication mechanisms of these nano-additives and identify the factors affecting their tribological performance. Finally, we briefly discuss the challenges faced by inorganic nanoparticles in lubrication applications and discuss future research directions. This review offers new perspectives to improve our understanding of inorganic nano-additives in tribology, as well as several new approaches to expand their practical applications.

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Introduction and Preliminary Investigation of Buoyancy Assisted Robots That Are Cheap, Safe, and Will Never Fall Down

10.1115/detc2021-70631 ◽

2021 ◽

Author(s):

Matthew David Williams ◽

Dennis Hong

Keyword(s):

Genetic Algorithm ◽

Preliminary Analysis ◽

Preliminary Investigation ◽

Research Work ◽

Legged Robots ◽

Dynamical Analysis ◽

Future Research ◽

The Novel ◽

Drag Forces ◽

New Family

Abstract We introduce and define a new family of mobile robots called BAR (Buoyancy Assisted Robots) that are cheap, safe, and will never fall down. BARs utilize buoyancy from lighter-than-air gases as a way to support the weight of the robot for locomotion. A new BAR robot named BLAIR (Buoyant Legged Actuated Inverted Robot) whose buoyancy is greater than its weight is also presented in this paper. BLAIRs can walk “upside-down” on the ceiling, providing unique advantages that no other robot platforms can. Unlike other legged robots, the mechanics of how BARs walk is fundamentally different. We also perform a preliminary investigation for BARs. This includes comparing safety, cost, and energy consumption with other commercially available robots. Additionally, the preliminary investigation also includes analyzing previous works relating to BARs. A dynamical analysis is performed on the novel robot BLAIR. This is presented to show the impacts of buoyant and drag forces on BLAIRs. Preliminary analysis with the prevalence of drag is presented with simulations using a genetic algorithm and simulations. Results show that BARs with different mechanisms prefer different styles of walking gaits such as prancing or skipping. This work lays the foundation for future research work on the gaits for BARs.

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Application of natural and synthetic polyamines as growth regulators to improve the freezing tolerance of winter wheat (Triticum aestivum L.)

Acta Agronomica Hungarica ◽

10.1556/aagr.60.2012.1.1 ◽

2012 ◽

Vol 60 (1) ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

D. Todorova ◽

I. Sergiev ◽

V. Alexieva

Keyword(s):

Winter Wheat ◽

Foliar Application ◽

Normal Growth ◽

Triticum Aestivum L ◽

Growth Conditions ◽

Freezing Stress ◽

Preliminary Treatment ◽

Fresh Weight ◽

Soil Culture ◽

Weight Losses

Wheat cultivars were grown as soil culture under normal growth conditions. Twoweek- old seedlings were exposed to 4°C for 6 h and then transferred to −12°C for 24 h in the dark. Twenty-four hours before freezing stress, some of the plants were sprayed with aqueous solutions of spermine, spermidine, putrescine, 1,3-diaminopropane (1,3-DAP) and diethylenetriamine (DETA). The data showed that freezing stress caused a decrease in the fresh weight, chlorophyll content and plant survival rate, accompanied by a simultaneous accumulation of free proline and the enhanced leakage of electrolytes. Preliminary treatment with polyamines caused a decline in electrolyte leakage and a considerable augmentation in proline quantity, indicating that the compounds are capable of preventing frost injury. Additionally, the foliar application of polyamines retarded the destruction of chlorophyll, and lessened fresh weight losses due to freezing stress. The synthetic triamine DETA was the most effective, having the most pronounced action in all the experiments, followed by the tetraamine spermine. The application of polyamines to wheat crops could be a promising approach for improving plant growth under unfavourable growth conditions, including freezing temperatures. The results demonstrate that treatment with polyamines could protect winter wheat by reducing the stress injuries caused by subzero temperatures.

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