bluuebunny/crossref_metadata_2025 huggingface dataset:
Low vulnerability of Arctic fox dens to climate change-related geohazards on Bylot Island, Nunavut, Canada
Authors: Lapierre Poulin Florence , Fortier Daniel , Berteaux Dominique
Published: February 2021

Climate change increases the risk of severe alterations to essential wildlife habitats. The Arctic fox (Vulpes lagopus (Linnaeus, 1758)) uses dens as shelters against cold temperatures and predators. These dens, needed for successful reproduction, are generally dug into the active layer on top of permafrost and reused across multiple generations. We assessed the vulnerability of Arctic fox dens to the increasing frequency of geohazards (thaw settlement, mass movements, and thermal erosion) that is arising from climate change. On Bylot Island (Nunavut, Canada) we developed, and calculated from field observations, a qualitative vulnerability index to geohazards for Arctic fox dens. Of the 106 dens studied, 14% were classified as highly vulnerable, whereas 17% and 69% had a moderate and low vulnerability, respectively. Vulnerability was not related to the probability of use for reproduction. Although climate change will likely impact Arctic fox reproductive dens, such impact is not a major threat to foxes of Bylot Island. Our research provides the first insights into the climate-related geohazards potentially affecting Arctic fox ecology in the next decades. The developed method is flexible and could be applied to other locations or other species that complete their life cycle in permafrost regions.
Microbial soil biodiversity in beech forests of European mountains
Authors: Dinca Lucian , Onet Aurelia , Samuel Alina Dora , Tognetti Roberto , Uhl Enno , Bosela Michal , Gömöryová Erika , Bielak Kamil , Skrzyszewski Jerzy , Hukić Emira , Zlatanov Tzvetan , de-Dios-García Javier , Tonon Giustino , Giammarchi Francesco , Svoboda Miroslav , Dobor Laura , Rolando Ludovica , Rauseo Jasmin , Pescatore Tanita , Garbini Gian Luigi , Visca Andrea , Patrolecco Luisa , Barra Caracciolo Anna , Grenni Paola
Published: February 2021

Fagus sylvatica L. is widely distributed across Europe thanks to its high adaptability in a wide variety of soils and climate. Microbial communities are essential for maintaining forest soil quality and are responsible for forest ecosystem functioning; the ability of soil microorganisms to respond to abiotic stressors (e.g., organic carbon losses, water scarcity, temperature changes) is crucial under ongoing environmental changes and also supports tree health. In this study, soil samples were collected from pure beech plots as part of the COST Action project CLIMO to find differences in microbial community characteristics and evaluate the effects of soil properties on microbial communities across gradients of elevation, latitude, and longitude. Positive relationships were found between organic carbon content and both microbial abundance and dehydrogenase activity. Dehydrogenase and catalase activities were elevation-correlated and microbial activities were longitude-correlated. In the most southern beech plot, the microbial community was abundant and displayed high activities. This shows that microbial communities could help tree populations to better adapt to predicted changes in environmental conditions in the future. We suggest that research into forest health and beech performance should also test soil microbial enzymatic activity, particularly under changing climate conditions, to assist in identifying adaptation strategies.
A benefit function for community detection based on edge and path of length two
Authors: Zhang Yaoyi , Huang Qingyu , Cao Guohai , Zhao Mengwei , Zhang Siyuan , Wu Yabo
Published: February 2021

In the field of community detection in complex networks, the most commonly used approach to this problem is the maximization of the benefit function known as “modularity”. In this study, it is found that the path of length two have the similar property as the edge, which is denser within communities and sparser between different communities. In order to take both edge and path of length two into consideration simultaneously, a self-loop is added to each node of the network and a novel benefit function has been defined. To divide the network into two communities, a second eigenvector method is proposed based on maximization of our new benefit function. Experimental results obtained by applying the method to karate club network and dolphin social network show the feasibility of our benefit function and the effectiveness of our algorithm.
A new probe of Gaussianity and isotropy with application to cosmic microwave background maps
Authors: Hamann J. , Le Gia Q. T. , Sloan I. H. , Wang Y. G. , Womersley R. S.
Published: February 2021

We introduce a new mathematical tool (a direction-dependent probe) to analyze the randomness of purported isotropic Gaussian random fields on the sphere. If the field is isotropic and Gaussian then the probe coefficients for a given direction should be realizations of uncorrelated scalar Gaussian random variables. To study the randomness of a field, we use the autocorrelation of the sequence of probe coefficients (which are just the Fourier coefficients [Formula: see text] if the [Formula: see text]-axis is taken in the probe direction). We introduce a particular function on the sphere (called the AC discrepancy) that accentuates the departure from Gaussianity and isotropy. We apply the probe to assess the full-sky cosmic microwave background (CMB) temperature maps produced by the Planck collaboration (PR2 2015 and PR3 2018), with special attention to the inpainted maps. We find that for some of the maps, there are many directions for which the departures are significant, especially near the galactic plane. We also look briefly at the noninpainted Planck maps, for which the computed AC discrepancy maps have a very different character, with features that are global rather than local.
A Combinatorial Characterization for Population Monotonic Allocations in Convex Independent Set Games
Authors: Liu Bin , Xiao Han , Fang Qizhi
Published: February 2021

Independent set games are cooperative games defined on graphs, where players are edges and the value of a coalition is the maximum size of independent sets in the subgraph defined by the coalition. In this paper, we study population monotonic allocation schemes for independent set games. For independent set games introduced by Deng et al. [X. Deng, T. Ibaraki and H. Nagamochi (1999). Algorithmic aspects of the core of combinatorial optimization games. Mathematics of Operations Research, 24(3), 751–766], we provide a combinatorial characterization for population monotonic allocation schemes in convex instances. For independent set games introduced by Xiao et al. [H. Xiao, Y. Wang and Q. Fang (2021). On the convexity of independent set games. Discrete Applied Mathematics, 291, 271–276], we prove the equivalence of convexity, population monotonicity and balancedness.
An elementary proof and detailed investigation of the bulk-boundary correspondence in the generic two-band model of Chern insulators
Authors: Chen Bo-Hung , Chiou Dah-Wei
Published: February 2021

With the inclusion of arbitrary long-range hopping and (pseudo)spin–orbit coupling amplitudes, we formulate a generic model that can describe any two-dimensional two-band bulk insulators, thus providing a simple framework to investigate arbitrary adiabatic deformations upon the systems of any arbitrary Chern numbers. Without appealing to advanced techniques beyond the standard methods of solving linear difference equations and applying Cauchy’s integral formula, we obtain a mathematically elementary yet rigorous proof of the bulk-boundary correspondence on a strip, which is robust against any adiabatic deformations upon the bulk Hamiltonian and any uniform edge perturbation along the edges. The elementary approach not only is more transparent about the underlying physics but also reveals various intriguing nontopological features of Chern insulators that have remained unnoticed or unclear so far. Particularly, if a certain condition is satisfied (as in most renowned models), the loci of edge bands in the energy spectrum and their (pseudo)spin polarizations can be largely inferred from the bulk Hamiltonian alone without invoking any numerical computation for the energy spectrum of a strip.
Underwater Image Enhancement with the Low-Rank Nonnegative Matrix Factorization Method
Authors: Liu Xiaopeng , Liu Cong , Liu Xiaochen
Published: February 2021

Due to the scattering and absorption effects in the undersea environment, underwater image enhancement is a challenging problem. To obtain the ground-truth data for training is also an open problem. So, the learning process is unavailable. In this paper, we propose a Low-Rank Nonnegative Matrix Factorization (LR-NMF) method, which only uses the degraded underwater image as input to generate the more clear and realistic image. According to the underwater image formation model, the degraded underwater image could be separated into three parts, the directed component, the back and forward scattering components. The latter two parts can be considered as scattering. The directed component is constrained to have a low rank. After that, the restored underwater image is obtained. The quantitative and qualitative analyses illustrate that the proposed method performed equivalent or better than the state-of-the-art methods. Yet, it’s simple to implement without the training process.
An evaluation of combined strategies for improving the performance of molecular docking
Authors: Xu Siqi , Wang Li , Pan Xianchao
Published: February 2021

Molecular docking is a fast and efficient computational method for the prediction of the binding mode and binding affinity between a ligand and a target protein at the atomic level. However, the performance of current docking programs is less than satisfactory. Herein, with a focus on free programs and scoring functions, the performances of LeDock and three standalone scoring functions were tested by 195 high-quality protein–ligand complexes. Results showed that the success rate for the best pose of the free available docking program LeDock achieved 89.20%, indicative of a strong sampling power. Based on the poses generated by LeDock, a comparative evaluation on other three non-commercial scoring functions, including DSX (DrugScore X), PoseScore and X-score was performed. Among all the evaluated scoring functions, DSX and X-score exhibited the best scoring power and ranking power, respectively. The performances of LeDock, DSX and X-score were similar in docking power test, which was much better than the PoseScore. Accordingly, it was suggested that the combination of pose sampling by LeDock with rescoring by DSX or X-score could improve the prediction accuracy of molecular docking and applied in the lead discovery.
Painlevé analysis, group invariant analysis, similarity reduction, exact solutions, and conservation laws of Mikhailov–Novikov–Wang equation
Authors: Ray S. Saha
Published: February 2021

In this paper, for the study of integrability, symmetry analysis, group invariant solutions and conservation laws, the Mikhailov–Novikov–Wang equation is considered. Firstly, Painlevé analysis is being employed to study the integrability properties for the considered equation so as to check the possibility that this equation passes the Painlevé test. Secondly, Lie group analysis is studied for finding the symmetries by using Lie classical group analysis method and to obtain its symmetry group, infinitesimal generator, Lie algebra commutation table, and similarity reductions. The vector fields and the symmetry reduction of this equation are calculated with the aid of Lie symmetry analysis. From the similarity reduction equation, some explicit exact solutions are derived. Finally, using the new conservation theorem proposed by Ibragimov [N. H. Ibragimov, A new conservation theorem, J. Math. Anal. Appl. 333 (2007) 311–328], the conservation laws of the aforesaid equation have been constructed.
Constraints on the Ricci dark energy cosmologies in Bianchi type I model
Authors: Hossienkhani H. , Azimi N. , Yousefi H.
Published: February 2021

The impact of anisotropy on the Ricci dark energy cosmologies is investigated where it is assumed that the geometry of the universe is described by Bianchi type I (BI) metric. The main goal is to determine the astrophysical constraints on the model by using the current available data as type Ia supernovae (SNIa), the Baryon Acoustic Oscillation (BAO), and the Hubble parameter [Formula: see text] data. In this regard, a maximum likelihood method is applied to constrain the cosmological parameters. Combining the data, it is found out that the allowed range for the density parameter of the model stands in [Formula: see text]. With the help of the Supernova Legacy Survey (SNLS) sample, we estimate the possible dipole anisotropy of the Ricci dark energy model. Then, by using a standard [Formula: see text] minimization method, it is realized that the transition epoch from early decelerated to current accelerated expansion occurs faster in Ricci dark energy model than [Formula: see text]CDM model. The results indicate that the BI model for the Ricci dark energy is consistent with the observational data.
A mathematical modeling of rabies with vaccination and culling
Authors: Thongtha Adison , Modnak Chairat
Published: February 2021

Rabies is a fatal contagious disease but preventable. It is a major public health problem in developing countries. Most of the rabies deaths around the world are caused by dog bites. If a person does not receive appropriate treatment after being exploded to rabies, the virus can damage the brain resulting in death. Since most of the deaths due to the transmission from dogs to humans, therefore, in this study, we will formulate a mathematical model that describes the dynamics of rabies virus transmission between dogs and humans. Also, we conduct both epidemic and endemic analysis. Optimal control theory is applied to seek cost-effective solutions for time-dependent vaccination and culling strategies against rabies outbreaks. Our results show that using vaccination during rabies outbreaks at the very beginning of the onset and culling infected dogs can reduce the number of infections significantly.
Adaptive energy consumption scheduling of multi-microgrid using whale optimization algorithm
Authors: Abedini Mohamad , Mostafai Mohamad
Published: February 2021

In this paper, we investigated the day-ahead scheduling of network consisting of several distributed generation sources and connected loads. This scheduling is an optimization problem that has two objective functions, namely, operating costs and the cost caused by the emission of pollutants. In this scheduling, while introducing a new structure for micro-grid utilization, the possibility of exchanging power among networks and exchanging power between networks and the upstream distribution network is provided. The uncertainty of distributed wind generation sources and solar units has been investigated using appropriate probabilistic distributions. Incent-driven load-responsiveness management programs have been used as to encourage subscribers to reduce their power consumption during high-load hours. Whale optimization algorithm has been used for scheduling of network.
Nanomedicine Technology and COVID-19 Outbreak: Applications and Challenges
Authors: Gupta Nitin , Bahl Shashi , Bagha Ashok Kumar , Vaid Supriya , Javaid Mohd , Haleem Abid
Published: February 2021

The coronavirus (COVID-19) pandemic is one of the biggest challenges in the field of healthcare. Nanomedicine is a developing area that has the potential to treat various diseases and control infections. Now, its applications are open for the treatment of COVID-19. We have studied relevant papers through Scopus, Google Scholar, Science Direct and ResearchGate on nanomedicine in context of COVID-19. This paper provides detailed information about nanomedicine in the context of healthcare. It further identifies the primary challenges faced in the current situation. This study provides details about the advancements in the area of nanomedicine in healthcare for fighting the COVID-19 pandemic. Finally, we have identified and discussed various significant applications of nanomedicine in solving challenges thrown by the COVID-19 pandemic. Researchers can work on developing applications of nanoparticles with the size of the novel Coronavirus. Nanomedicine is helpful to repair the cells of an infected patient the help of repair proteins. It also plays a vital role in testing medicine and helps many clinical trials get approval from healthcare agencies. In the future, nanomedicine will be helpful for fighting against this pandemic and creating advancements in healthcare.
Decentralized Financial Market Infrastructures: Evolution from Intermediated Structures to Decentralized Structures for Financial Agreements
Authors: Feenan Sara , Heller Daniel , Lipton Alexander , Morini Massimo , Ram Rhomaios , Sams Robert , Swanson Tim , Yong Stanley , Zalles Diana Barrero
Published: February 2021

Financial market infrastructures (FMIs) have evolved as core elements of highly intermediated financial markets partly due to the technological limitations of the time when they were first designed. Organizations and firms were unable to share records without having to entrust a single party to manage them; hence this phenomenon of intermediation has led to significant information silos. Simultaneously, it has driven the structure of business models, as well as regulatory supervision and oversight, in ways that furthered intermediation and also created a misalignment of incentives and risk taking between entities now categorized as systemically important financial institutions (SIFIs) and systemically important financial market infrastructures. Over time, this consolidation has led to highly concentrated FMIs and with it, concentrated risks. Some of these risks go beyond the credit risks of just one or two institutions, becoming instead systemic risks that are continuously monitored by regulatory bodies. Over the past decade, advances in public key cryptography, hash functions, virtualization, distributed consensus, multiparty computation, and peer-to-peer networking have led to experimentation around record sharing between erstwhile competitive firms. Over the past five years, a series of independent efforts has chaperoned regulatory requirements into a digital, automated state that enables secure information sharing in full compliance with the law, while simultaneously enabling market participants to mutualize infrastructure that would otherwise be run by a single trusted party. With these developments, many of the services that centralized intermediaries currently provide could potentially be replaced by decentralized infrastructures or decentralized financial market infrastructure (dFMI). dFMI also enables a change in business structure, where a re-alignment of incentives can take place such that those firms taking risks can fully bear the consequences of these risks.
Mafic rocks from the southern Alxa block of Northwest China and its geodynamic evolution in the Paleozoic
Authors: Zhang Liqi , Zhang Hongfei , Hawkesworth Chris , Luo Biji , Yang He
Published: February 2021

The southern margin of the Alxa Terrane is located between the North Qilian Orogenic Belt and the inner Alxa block, and Paleozoic mafic magmatism records the geodynamic evolution at different stages in the orogenic cycle. New zircon U−Pb ages and whole-rock geochemistry reveal three groups of mafic rocks in the southern margin of the Alxa block: (i)
c.
480 Ma Xijing gabbros, characterized by high Ba/Th and low Th/La ratios with low ε
Nd
(
t
) (−5.7 to −4.9) values, implying their derivation from enriched mantle metasomatized by slab-derived fluids; (ii)
c.
440 Ma Xijing and Jiling hornblende gabbros which have high Th/La and low Ba/Th ratios, suggesting that they were produced by partial melting of mantle modified by previously subducted sediments; (iii)
c.
250 Ma Xijing pyroxenites, which are cumulates with relatively high ε
Nd
(
t
) (+5.2 to  +  5.9), indicating that their host magmas were derived from relatively depleted mantle. Together with published results, these new data highlight that the
c.
480 and
c.
440 Ma mafic magmas were related to the northward subduction of the North Qilian oceanic slab and later post-collisional lithospheric delamination, respectively. The
c.
250 Ma Xijing pyroxenites were related to younger lithospheric extension in the development of the Central Asian Orogenic Belt in the Alxa block.

Supplementary material
: Supplementary tables A1–A7 are available at
https://doi.org/10.6084/m9.figshare.c.5287657
Binary Redox Couples for Highly Transparent and High-Voltage Dye-Sensitized Solar Cells
Authors: Yoo Kicheon , Deb Nath Narayan Chandra , Kang Hyeong Cheol , Muthu Senthilkumar , Lee Jae-Joon
Published: February 2021

The conventional iodine-based (I−/I3
−) electrolyte used in dye-sensitized solar cells (DSSCs) presents several limitations, such as ∼30% absorption of visible light in the wavelength range of 300–500 nm and a large potential difference between the Fermi level of I−/I3
− and the HOMO level of the dye. This has a negative impact on the characteristics of DSSC such as transparency and open circuit voltage (Voc). In the present work, a series of transparent electrolytes are prepared using various additives such as I2, LiI, guanidine thiocyanate/guanidine nitrate (GuSCN/GuNO3), and Br2 to obtain highly transparent and high voltage DSSCs. The results demonstrate that the usage of the optimized electrolyte consisting of 0.003 M Br2, 0.01 M LiI, and 0.1 M GuNO3, with the binary redox couple (I−, Br−)/(I3
−, I2Br−), contributes to an ∼25% increase in transmittance compared to that of the conventional electrolyte, while the concentration of I3
− is significantly reduced. Furthermore, the downward shift in the Fermi level of the binary redox system is shown to provide an ∼100 mV enhancement in the Voc of the DSSC compared with that of the conventional electrolyte based DSSC. In addition, the devices with the optimized binary redox system achieve a power conversion efficiency of ∼7.94% which is closely comparable to the performance of conventional (I−/I3
−) electrolyte-based DSSCs. Thus, the present study could provide immense insights toward the fabrication of high-voltage and transparent DSSCs for the application in transparent photovoltaic windows. Furthermore, by using a binary redox electrolyte, the DSSCs that operative under a 2000 lux compact fluorescent lamp (CFL) were also successfully fabricated and yielded a promising efficiency of 23.6%.
Composition Semigroups on Weighted Bergman Spaces Induced by Doubling Weights
Authors: Wu Fanglei
Published: February 2021

We prove that composition semigroups are strongly continuous on weighted Bergman spaces with doubling weights. Point spectra and compact resolvent operators of infinitesimal generators of composition semigroups are characterized.
Clinical Management of Hypodontia of Two Mandibular Incisors
Authors: Paduano Sergio , Barbara Lorenza , Aiello Domenico , Pellegrino Marianna , Festa Felice
Published: February 2021

This article presents the clinical management of a patient with bilateral congenitally missing mandibular incisors. This condition is relatively rare and always needs a careful diagnosis and treatment planning. The chosen treatment strategy for this patient included space closure by protraction of the mandibular posterior teeth and canine substitution of missing incisors. Furthermore, the problems arising from this treatment plan, such as premolar-protected occlusion and tooth size discrepancy, are discussed. From the case presented in this study, we can conclude that space closure may be considered an efficient treatment approach for achieving satisfactory functional and aesthetic results.
The Effects of Acupuncture on Pregnancy Outcomes of Recurrent Implantation Failure: A Systematic Review and Meta-Analysis
Authors: Li Menglin , Liu Yunyun , Wang Haoran , Zheng Shuzhen , Deng Yinhe , Li Yuemei
Published: February 2021

Objective. To systematically evaluate the efficacy and safety of acupuncture for patients with recurrent implantation failure (RIF) undergoing in vitro fertilization-embryo transfer (IVF-ET) and hopefully provide reliable guidance for clinicians and patients. Methods. Through searching domestic and foreign medical journals, the literature of randomized controlled trials (RCTs) of acupuncture for RIF undergoing IVF-ET was collected. RevMan 5.3 software was used for meta-analysis and Cochrane’s risk of bias assessment tool was used to evaluate the quality of the included studies. Results. Seven documents meeting the criteria were finally included. The results showed that the intervention group contributes more in outcomes including clinical pregnancy rate (RR = 1.90, 95% CI (1.51, 2.40),

P
<
0.05

), biochemical pregnancy rate (RR = 1.59, 95% CI (1.27, 1.99),

P
<
0.05

), embryo implantation rate (RR = 1.89, 95% CI (1.47, 2.45),

P
<
0.05

), and endometrial thickness (MD = 1.11, 95% CI (0.59, 1.63),

P
<
0.05

) when compared with the control group, and the difference is statistically significant. In terms of the number of embryo transfers and the type of endometrium, the difference between the acupuncture group and the control group was not statistically significant. Conclusion. Acupuncture therapy on patients with RIF can improve the pregnancy outcome of patients. It is a relatively effective treatment with satisfactory safety and suitable for clinical application. However, as the quality of the included studies is not good enough, the conclusion of this meta-analysis should be treated with caution. More double-blind RCTs equipped with high quality and large samples are expected for the improvement of the level of evidence.
The Hsp90 Inhibitor 17‐DMAG Attenuates Hyperglycemia‐Enhanced Hemorrhagic Transformation in Experimental Stroke
Authors: Zhang Jiaming , Wang Kai , Qi Jia , Cao Xiaodong , Wang Feng
Published: February 2021

Introduction. Hemorrhagic transformation (HT) is one of the most common complications of ischemic stroke which is exacerbated by hyperglycemia. Oxidative stress, inflammatory response, and matrix metalloproteinases (MMPs) have been evidenced to play a vital role in the pathophysiology of HT. Our previous study has reported that 17‐DMAG, an Hsp90 inhibitor, protects the brain against ischemic injury via inhibiting inflammation and reducing MMP‐9 after ischemia. However, whether 17‐DMAG would attenuate HT in hyperglycemic middle cerebral artery occlusion (MCAO) rats is still unknown. Methods. Acute hyperglycemia was induced by an injection of 50% dextrose. Rats were pretreated with 17‐DMAG before MCAO. Infarction volume, hemorrhagic volume neurological scores, expressions of inflammatory molecules and tight junction proteins, and activity of MMP‐2 and MMP‐9 were assessed 24 h after MCAO. Results. 17‐DMAG was found to reduce HT, improve neurological function, and inhibit expressions of inflammatory molecules and the activation of MMPs at 24 h after MCAO. Conclusion. These results implicated that Hsp90 could be a novel therapeutic target in HT following ischemic stroke.
Wireless Sensor Network Deployment in Cyberphysical Machine Tool System Based on Optimal Allocation of Memory Buffers
Authors: Zhou Xiaoyang
Published: February 2021

As an important direction of Industry 4.0, cyberphysical machine tool systems (CPMTS) can realize the deep integration and real‐time interaction of physical components and information to optimize manufacturing processes. Wireless sensor network (WSN), an important part of CPMTS, is responsible for data collection and transmission. However, in the process of data transmission, due to memory limitations and noise interference, unreasonable sensor distribution will affect the performance of CPMTS. At the same time, data accuracy will be affected due to the resource constraints of CPMTS. To solve the problems above, this paper firstly presented a single‐station transfer model to ensure the layout of sensors in each sink, which can meet the detection capability of fault/monitoring data. Then, by using fuzzy graphs, a multihop‐station transfer model and data‐collecting model are developed to describe the data flow and memory allocation in the wireless network. Taking noise interference and data position into consideration, a MILP problem is formulated and the optimization solution is obtained by using the “branch and bound” method. Finally, case studies about optimal sensor distribution on the single station and path optimization on the multihop station are presented to illustrate the proposed strategy. The case studies validated that the proposed sensor distribution in a single station can achieve higher detectability with fewer resources, and the optimization path strategy can achieve the best performance in two proposed experiments, compared to the shortest path and noninferior path strategies.
Hormone Replacement Therapy and Aging: A Potential Therapeutic Approach for Age‐Related Oxidative Stress and Cardiac Remodeling
Authors: Szabó Renáta , Hoffmann Alexandra , Börzsei Denise , Kupai Krisztina , Veszelka Médea , Berkó Anikó Magyariné , Pávó Imre , Gesztelyi Rudolf , Juhász Béla , Turcsán Zsolt , Pósa Anikó , Varga Csaba
Published: February 2021

Advanced age is an independent risk factor for cardiovascular diseases, which might be further exacerbated by estrogen deficiency. Hormone replacement therapy (HRT) decreases cardiovascular risks and events in postmenopausal women; however, its effects are not fully elucidated in older individuals. Thus, the aim of our study is to examine the impact of HRT on oxidant/antioxidant homeostasis and cardiac remodeling. In our experiment, control (fertile) and aging (~20‐month‐old) female Wistar rats were used. Aging rats were further divided into estrogen‐ (E2, 0.1 mg/kg/day per os) or raloxifene‐ (RAL, 1.0 mg/kg/day per os) treated subgroups. After 2 weeks of treatment, cardiac heme oxygenase (HO) activity, total glutathione (GSH) content, matrix metalloproteinase‐2 (MMP‐2) activity, and the concentrations of collagen type I and tissue inhibitor of metalloproteinase (TIMP‐2), as well as the infarct size, were determined. The aging process significantly decreased the antioxidant HO activity and GSH content, altered the MMP‐2/TIMP‐2 signaling, and resulted in an excessive collagen accumulation, which culminated in cardiovascular injury. However, 2 weeks of either E2 or RAL treatment enhanced the antioxidant defense mechanisms and attenuated cardiac remodeling related to aging. Our findings clearly show that 2‐week‐long HRT is a potential intervention to bias successful cardiovascular aging via reducing oxidative damage and cardiovascular dysfunction.
Gymnema inodorum (Lour.) Decne. Extract Alleviates Oxidative Stress and Inflammatory Mediators Produced by RAW264.7 Macrophages
Authors: Dunkhunthod Benjawan , Talabnin Chutima , Murphy Mark , Thumanu Kanjana , Sittisart Patcharawan , Eumkeb Griangsak
Published: February 2021

Gymnema inodorum (Lour.) Decne. (G. inodorum) is widely used in Northern Thai cuisine as local vegetables and commercial herb tea products. In the present study, G. inodorum extract (GIE) was evaluated for its antioxidant and anti‐inflammatory effects in LPS plus IFN‐γ‐induced RAW264.7 cells. Major compounds in GIE were evaluated using GC‐MS and found 16 volatile compounds presenting in the extract. GIE exhibited antioxidant activity by scavenging the intracellular reactive oxygen species (ROS) production and increasing superoxide dismutase 2 (SOD2) mRNA expression in LPS plus IFN‐γ‐induced RAW264.7 cells. GIE showed anti‐inflammatory activity through suppressing nitric oxide (NO), proinflammatory cytokine production interleukin 6 (IL‐6) and also downregulation of the expression of cyclooxygenase‐2 (COX‐2), inducible nitric oxide synthase (iNOS), and IL‐6 mRNA levels in LPS plus IFN‐γ‐induced RAW264.7 cells. Mechanism studies showed that GIE suppressed the NF‐κB p65 nuclear translocation and slightly decreased the phosphorylation of NF‐κB p65 (p‐NF‐κB p65) protein. Our studies applied the synchrotron radiation‐based FTIR microspectroscopy (SR‐FTIR), supported by multivariate analysis, to identify the FTIR spectral changes based on macromolecule alterations occurring in RAW264.7 cells. SR‐FTIR results demonstrated that the presence of LPS plus IFN‐γ in RAW264.7 cells associated with the increase of amide I/amide II ratio (contributing to the alteration of secondary protein structure) and lipid content, whereas glycogen and other carbohydrate content were decreased. These findings lead us to believe that GIE may prevent oxidative damage by scavenging intracellular ROS production and activating the antioxidant gene, SOD2, expression. Therefore, it is possible that the antioxidant properties of GIE could modulate the inflammation process by regulating the ROS levels, which lead to the suppression of proinflammatory cytokines and genes. Therefore, GIE could be developed into a novel antioxidant and anti‐inflammatory agent to treat and prevent diseases related to oxidative stress and inflammation.
The Dual Effects of Reactive Oxygen Species on the Mandibular Alveolar Bone Formation in SOD1 Knockout Mice: Promotion or Inhibition
Authors: Zhang Yunyan , Yang Yuzhi , Xu Mingxue , Zheng Jingwen , Xu Yuchan , Chen Guoqing , Guo Qiang , Tian Weidong , Guo Weihua
Published: February 2021

The status of reactive oxygen species (ROS) correlates closely with the normal development of the oral and maxillofacial tissues. Oxidative stress caused by ROS accumulation not only affects the development of enamel and dentin but also causes pathological changes in periodontal tissues (periodontal ligament and alveolar bone) that surround the root of the tooth. Although previous studies have shown that ROS accumulation plays a pathologic role in some oral and maxillofacial tissues, the effects of ROS on alveolar bone development remain unclear. In this study, we focused on mandibular alveolar bone development of mice deficient in superoxide dismutase1 (SOD1). Analyses were performed using microcomputerized tomography (micro‐CT), TRAP staining, immunohistochemical (IHC) staining, and enzyme‐linked immunosorbent assay (ELISA). We found for the first time that slightly higher ROS in mandibular alveolar bone of SOD1(‐/‐) mice at early ages (2‐4 months) caused a distinct enlargement in bone size and increased bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and expression of alkaline phosphatase (ALP), Runt‐related transcription factor 2 (Runx2), and osteopontin (OPN). With ROS accumulation to oxidative stress level, increased trabecular bone separation (Tb.Sp) and decreased expression of ALP, Runx2, and OPN were found in SOD1(‐/‐) mice at 6 months. Additionally, dosing with N‐acetylcysteine (NAC) effectively mitigated bone loss and normalized expression of ALP, Runx2, and OPN. These results indicate that redox imbalance caused by SOD1 deficiency has dual effects (promotion or inhibition) on mandibular alveolar bone development, which is closely related to the concentration of ROS and the stage of growth. We present a valuable model here for investigating the effects of ROS on mandibular alveolar bone formation and highlight important roles of ROS in regulating tissue development and pathological states, illustrating the complexity of the redox signal.
Cortisol Secretion and Subsequent Impaired Lymphopoiesis after Starvation Can Be Reduced by Moxibustion Treatment
Authors: Hwang Kyung Ho , Jang Kiyoung , Nam Sang-Yun , Kim Yong Ju
Published: February 2021

As a known steroid hormone, cortisol is involved in gluconeogenesis. Uninterrupted cortisol secretion has fatal effects, both physically and psychologically, because cortisol counteracts the immune response. Moxibustion (Mox) treatment is a traditional technique used in East Asia, which therapeutically transfers heat to certain points on the body surface. In the present study, the effect of Mox treatment on stress hormone secretion was investigated using a mouse model of starvation, in which Mox was applied on the Zhongwan acupoint (CV12). First, high cortisol levels induced by starvation were dose-dependently reduced by Mox treatment. In addition, the stress-induced decline in lymphoid progenitor cell production accompanied by altered cellularity in the thymus, bone marrow, and spleen was also significantly recovered by Mox treatment. Taken together, these findings indicated that Mox treatment reduces stress hormone secretion, which may rescue stress-induced lymphopoiesis impairment. These observations also suggested that enhanced resistance to stress may be one of the mechanisms underlying the immunomodulatory effects of Mox treatment.
YOLOv3-Litchi Detection Method of Densely Distributed Litchi in Large Vision Scenes
Authors: Wang Hongjun , Dong Lizhong , Zhou Hao , Luo Lufeng , Lin Guichao , Wu Jinlong , Tang Yunchao
Published: February 2021

Accurate and reliable fruit detection in the orchard environment is an important step for yield estimation and robotic harvesting. However, the existing detection methods often target large and relatively sparse fruits, but they cannot provide a good solution for small and densely distributed fruits. This paper proposes a YOLOv3-Litchi model based on YOLOv3 to detect densely distributed litchi fruits in large visual scenes. We adjusted the prediction scale and reduced the network layer to improve the detection ability of small and dense litchi fruits and ensure the detection speed. From flowering to 50 days after maturity, we collected a total of 266 images, including 16,000 fruits, and then used them to construct the litchi dataset. Then, the k-means++ algorithm is used to cluster the bounding boxes in the labeled data to determine the priori box size suitable for litchi detection. We trained an improved YOLOv3-Litchi model, tested its litchi detection performance, and compared YOLOv3-Litchi with YOLOv2, YOLOv3, and Faster R-CNN on the actual detection effect of litchi and used the F1 value and the average detection time as the assessed value. The test results show that the F1 of YOLOv3-Litchi is higher than that of YOLOv2 algorithm 0.1, higher than that of YOLOv3 algorithm 0.08, and higher than that of Faster R-CNN algorithm 0.05; the average detection time of YOLOv3-Litchi is 29.44 ms faster than that of YOLOv2 algorithm, 19.56 ms faster than that of YOLOv3 algorithm ms, and 607.06 ms faster than that of Faster R-CNN algorithm. And the detection speed of the improved model is faster. The proposed model remits optimal detection performance for small and dense fruits. The work presented here may provide a reference for further study on fruit-detection methods in natural environments.
Impact of Large-Scale Climate Indices on Meteorological Drought of Coastal Ghana
Authors: Addi Martin , Asare Kofi , Fosuhene Samuel Kofi , Ansah-Narh Theophilus , Aidoo Kenneth , Botchway Comfort Gyasiwaa
Published: February 2021

The devastating effects of drought on agriculture, water resources, and other socioeconomic activities have severe consequences on food security and water resource management. Understanding the mechanism that drives drought and predicting its variability is important for enhancing early warning and disaster risk management. In this study, meteorological droughts over six coastal synoptic stations were investigated using three-month Standardized Precipitation Index (SPI). The dry seasons of November-December-January (NDJ), December-January-February (DJF), and January-February-March (JFM) were the focal seasons for the study. Trends of dry seasons SPIs were evaluated using seasonal Mann–Kendall test. The relationship between drought SPI and ocean-atmosphere climate indices and their predictive ability were assessed using Pearson correlation and Akaike Information Criterion (AIC) stepwise regression method to select best climate indices at lagged timestep that fit the SPI. The SPI exhibited moderate to severe drought during the dry seasons. Accra exhibited a significant increasing SPI trend in JFM, NDJ, and DJF seasons. Besides, Saltpond during DJF, Tema, and Axim in NDJ season showed significant increasing trend of SPI. In recent years, SPIs in dry seasons are increasing, an indication of weak drought intensity, and the catchment areas are becoming wetter in the traditional dry seasons. Direct (inverse) relationship was established between dry seasons SPIs and Atlantic (equatorial Pacific) ocean's climate indices. The significant climate indices modulating drought SPIs at different time lags are a combination of either Nino 3.4, Nino 4, Nino 3, Nino 1 + 2, TNA, TSA, AMM, or AMO for a given station. The AIC stepwise regression model explained up to 48% of the variance in the drought SPI and indicates Nino 3.4, Nino 4, Nino 3, Nino 1 + 2, TNA, TSA, AMM, and AMO have great potential for seasonal drought prediction over Coastal Ghana.
Emergence of Enzalutamide Resistance in Prostate Cancer is Associated with BCL-2 and IKKB Dependencies
Authors: Liang Yi , Jeganathan Sujeeve , Marastoni Stefano , Sharp Adam , Figueiredo Ines , Marcellus Richard , Mawson Amanda , Shalev Zvi , Pesic Aleksandra , Sweet Joan , Guo Haiyang , Uehling David , Gurel Bora , Neeb Antje , He Housheng Hansen , Montgomery Bruce , Koritzinsky Marianne , Oakes Samantha , de Bono Johann S. , Gleave Martin , Zoubeidi Amina , Wouters Bradly G. , Joshua Anthony M.
Published: February 2021

Purpose:

Although enzalutamide (ENZ) has been widely used to treat de novo or castration-resistant metastatic prostate cancer, resistance develops and disease progression is ultimately inevitable. There are currently no approved targeted drugs to specifically delay or overcome ENZ resistance.

Experimental Design:

We selected several ENZ-resistant cell lines that replicated clinical characteristics of the majority of patients with ENZ-resistant disease. A high-throughput pharmacologic screen was utilized to identify compounds with greater cytotoxic effect for ENZ-resistant cell lines, compared with parental ENZ-sensitive cells. We validated the potential hits in vitro and in vivo, and used knockdown and overexpression assays to study the dependencies in ENZ-resistant prostate cancer.

Results:

ABT199 (BCL-2 inhibitor) and IMD0354 (IKKB inhibitor) were identified as potent and selective inhibitors of cell viability in ENZ-resistant cell lines in vitro and in vivo which were further validated using loss-of-function assays of BCL-2 and IKKB. Notably, we observed that overexpression of BCL-2 and IKKB in ENZ-sensitive cell lines was sufficient for the emergence of ENZ resistance. In addition, we confirmed that BCL-2 or IKKB inhibitors suppressed the development of ENZ resistance in xenografts. However, validation of both BCL-2 and IKKB in matched castration-sensitive/resistant clinical samples showed that, concurrent with the development of ENZ/abiraterone resistance in patients, only the protein levels of IKKB were increased.

Conclusions:

Our findings identify BCL-2 and IKKB dependencies in clinically relevant ENZ-resistant prostate cancer cells in vitro and in vivo, but indicate that IKKB upregulation appears to have greater relevance to the progression of human castrate-resistant prostate cancer.
Lipidome-based Targeting of STAT3-driven Breast Cancer Cells Using Poly-l-glutamic Acid–coated Layer-by-Layer Nanoparticles
Authors: Tošić Isidora , Heppler Lisa N. , Egusquiaguirre Susana P. , Boehnke Natalie , Correa Santiago , Costa Daniel F. , Moore Elizabeth A. Grossman , Pal Sharmistha , Richardson Douglas S. , Ivanov Alexander R. , Haas-Kogan Daphne A. , Nomura Daniel K. , Hammond Paula T. , Frank David A.
Published: February 2021

The oncogenic transcription factor STAT3 is aberrantly activated in 70% of breast cancers, including nearly all triple-negative breast cancers (TNBCs). Because STAT3 is difficult to target directly, we considered whether metabolic changes driven by activated STAT3 could provide a therapeutic opportunity. We found that STAT3 prominently modulated several lipid classes, with most profound effects on N-acyl taurine and arachidonic acid, both of which are involved in plasma membrane remodeling. To exploit these metabolic changes therapeutically, we screened a library of layer-by-layer (LbL) nanoparticles (NPs) differing in the surface layer that modulates interactivity with the cell membrane. We found that poly-l-glutamic acid (PLE)–coated NPs bind to STAT3-transformed breast cancer cells with 50% greater efficiency than to nontransformed cells, and the heightened PLE-NP binding to TNBC cells was attenuated by STAT3 inhibition. This effect was also observed in densely packed three-dimensional breast cancer organoids. As STAT3-transformed cells show greater resistance to cytotoxic agents, we evaluated whether enhanced targeted delivery via PLE-NPs would provide a therapeutic advantage. We found that cisplatin-loaded PLE-NPs induced apoptosis of STAT3-driven cells at lower doses compared with both unencapsulated cisplatin and cisplatin-loaded nontargeted NPs. In addition, because radiation is commonly used in breast cancer treatment, and may alter cellular lipid distribution, we analyzed its effect on PLE-NP–cell binding. Irradiation of cells enhanced the STAT3-targeting properties of PLE-NPs in a dose-dependent manner, suggesting potential synergies between these therapeutic modalities. These findings suggest that cellular lipid changes driven by activated STAT3 may be exploited therapeutically using unique LbL NPs.
Mapping Bone Surface Composition Using Real-Time Surface Tracked Micro-Raman Spectroscopy
Authors: Shah Furqan A. , Ruscsák Krisztina , Palmquist Anders
Published: February 2021

The surface of bone tells a story – one that is worth a thousand words – of how it is built and how it is repaired. Chemical (i.e., composition) and physical (i.e., morphology) characteristics of the bone surface are analogous to a historical record of osteogenesis and provide key insights into bone quality. Analysis of bone chemistry is of particular relevance to the advancement of human health, cell biology, anthropology/archaeology, and biomedical engineering. Although scanning electron microscopy remains a popular and versatile technique to image bone across multiple length scales, limited chemical information can be obtained. Micro-Raman spectroscopy is a valuable tool for nondestructive chemical/compositional analysis of bone. However, signal integrity losses occur frequently during wide-field mapping of non-planar surfaces. Samples for conventional Raman imaging are, therefore, rendered planar through polishing or sectioning to ensure uniform signal quality. Here, we demonstrate ν1 PO43- and ν1 CO32- peak intensity losses where the sample surface and the plane of focus are offset by over 1–2 μm when underfocused and 2–3 μm when overfocused at 0.5–1 s integration time (15 mW, 633 nm laser). A technique is described for mapping the composition of the inherently irregular/non-planar surface of bone. The challenge posed by the native topology characteristic of this unique biological system is circumvented via real-time focus-tracking based on laser focus optimization by continuous closed-loop feedback. At the surface of deproteinized and decellularized/defatted sheep tibial cortical bone, regions of interest up to 1 mm2 were scanned at micrometer and submicrometer resolution. Despite surface height deviations exceeding 100 μm, it is possible to seamlessly probe local gradients in organic and inorganic constituents of the extracellular matrix as markers of bone metabolism and bone turnover, blood vessels and osteocyte lacunae, and the rope-like mineralized bundles that comprise the mineral phase at the bone surface.