bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Monogamy of Spatio-Temporal Correlations and the Black Hole Information Loss Paradox
Authors: Marletto Chiara , Vedral Vlatko , Virzì Salvatore , Rebufello Enrico , Avella Alessio , Piacentini Fabrizio , Gramegna Marco , Degiovanni Ivo Pietro , Genovese Marco
Published: February 2020

Pseudo-density matrices are a generalisation of quantum states and do not obey monogamy of quantum correlations. Could this be the solution to the paradox of information loss during the evaporation of a black hole? In this paper we discuss this possibility, providing a theoretical proposal to extend quantum theory with these pseudo-states to describe the statistics arising in black-hole evaporation. We also provide an experimental demonstration of this theoretical proposal, using a simulation in optical regime, that tomographically reproduces the correlations of the pseudo-density matrix describing this physical phenomenon.
Numerical Simulation on Convection and Thermal Radiation of Casson Fluid in an Enclosure with Entropy Generation
Authors: Alzahrani A. K. , Sivasankaran S. , Bhuvaneswari M.
Published: February 2020

The goal of the current numerical simulation is to explore the impact of aspect ratio, thermal radiation, and entropy generation on buoyant induced convection in a rectangular box filled with Casson fluid. The vertical boundaries of the box are maintained with different constant thermal distribution. Thermal insulation is executed on horizontal boundaries. The solution is obtained by a finite volume-based iterative method. The results are explored over a range of radiation parameter, Casson fluid parameter, aspect ratio, and Grashof number. The impact of entropy generation is also examined in detail. Thermal stratification occurs for greater values of Casson liquid parameters in the presence of radiation. The kinetic energy grows on rising the values of Casson liquid and radiation parameters. The thermal energy transport declines on growing the values of radiation parameter and it enhances on rising the Casson fluid parameter.
Challenges of Electronic Reverse Auctions in Construction Industry—A Review
Authors: Hanák Tomáš , Marović Ivan , Jajac Nikša
Published: February 2020

The innovation of construction procurement by means of electronic reverse auctions is a controversial subject of discussion among both researchers and practitioners. This paper consolidates and critically discusses current knowledge concerning the adoption and use of electronic reverse auctions in the light of specific features of the construction industry. A systematic literature review has been employed to select papers indexed in Scopus and Web of Science databases. The findings of the study indicate that studies are addressing especially five main areas, i.e., suitability of electronic reverse auction (eRA) for construction tenders, related drivers and barriers, ethical considerations, savings potential and bidding behavior, and bid distribution. Accordingly, the authors are suggesting three directions in which future research should focus on mutual interaction of electronic reverse auctions and long-term effects on construction project outcomes.
Highly Stable All-Fiber-Ring Short-Cavity Continuously Tuned Swept Source
Authors: Yang Zhiwei , Wu Xu , Ouyang Deqin , Sun Huibin , Ruan Shuangchen
Published: February 2020

In this study, we present a swept source that can intelligently control its sweeping speed while satisfying the commercial stability and miniaturization standards. The source’s central wavelength of the output spectrum is 1300 nm and spectral width is greater than 100 nm. Meanwhile, the scan frequency can be adjusted to range from 20 to 100 kHz, and the stability degree of the optical capacity is less than 0.34%. Additionally, this study establishes a numerical model for the swept-source optical coherence tomography (SS–OCT) system and introduces a numerical simulation of the signal produced during the OCT imaging process. The simulation results are helpful to guide the design and construction of the future OCT systems.
Cell ID and Angle of Departure Estimation for Millimeter-wave Cellular Systems in Line-of-Sight Dominant Conditions Using Zadoff-Chu Sequence Based Beam Weight
Authors: Kim Yeong Jun , Cho Yong Soo
Published: February 2020

Millimeter-wave (mmWave) bands is considered for fifth-generation (5G) cellular systems because abundant spectrum is available for mobile broadband communications. In mmWave communication systems, accurate beamforming is important to compensate for high attenuation in the mmWave frequency band and to extend the transmission range. However, with the existing beamformers in mmWave cellular systems, the mobile station (MS) cannot identify the source (base station; BS) of the received beam because there are many neighboring BSs transmitting their training signals, requiring a large overhead. This paper proposes a new beam weight generation method for transmitting (Tx) beamformers at the BS in mmWave cellular systems during a beam training period. Beam weights are generated for Tx beamformers at neighboring BSs, so that a mobile station (MS) can estimate the source (cell ID; CID) and angle of departure (AoD) for each BS in multi-cell environments. A CID and AoD estimation method for mmWave cellular systems in a line-of-sight (LOS) dominant condition is presented using the beam weights generated by Zadoff-Chu sequence. A simulation is conducted in a LOS dominant condition to show that the performances of CID detection and AoD estimation are similar for both the proposed and conventional methods. In the conventional methods, the DFT-based beamforming weight is used for Tx beamformer at the BS and orthogonal matching pursuit (OMP) algorithm is used for AoD estimation at the MS. The proposed method significantly reduces the processing time (1.6–6.25%) required for beam training compared to the conventional method.
Optimization of β-galactosidase Production by Batch Cultures of Lactobacillus leichmannii 313 (ATCC 7830™)
Authors: Deng Yongjin , Xu Min , Ji Dawei , Agyei Dominic
Published: February 2020

The endoenzyme β-galactosidase (β-d-galactoside galactohydrolase; EC 3.2.1.23) has been used at industrial scales for the preparation of lactose-free milk and for the conversion of lactose to galacto-oligosaccharides (GOS) prebiotics. In this study, using Plackett–Burman (PB) design and the response surface methodology (RSM), the batch growth conditions for the production of β-galactosidase in DeMan-Rogosa-Sharpe (MRS) media have been studied and optimized for Lactobacillus leichmannii 313 (ATCC 7830™) for the first time. The incubation temperature (30  <  T  <  55 °C), starting pH (5.5  <  pH  <  7.5), and carbon source (glucose, lactose, galactose, fructose, and sucrose) were selected as the significant variables for optimization. The maximum crude β-galactosidase production (measured by specific activity) was 4.5 U/mg proteins and was obtained after 12 h of fermentation. The results of the PB design and further optimization by RSM showed that the initial pH of 7.0 and 15.29 g/L of lactose were the levels that gave the optimum observed and predicted β-galactosidase activities of 23.13 U/mg and 23.40 U/mg, respectively. Through RSM optimization, β-galactosidase production increased significantly (over five-fold) in optimized medium (23.13 U/mg), compared with unoptimized medium (4.5 U/mg). Moreover, the crude enzyme obtained was able to hydrolyze lactose and also produce galacto-oligosaccharides. Because its ability to produce β-galactosidase was significantly improved through optimization by RSM, L. leichmannii 313 can serve as a potential source of β-galactosidase for food applications at an industrial scale.
A Blockchain based PKI Validation System based on Rare Events Management
Authors: Talamo Maurizio , Arcieri Franco , Dimitri Andrea , Schunck Christian H.
Published: February 2020

Public key infrastructures (PKIs) are the cornerstone for the security of the communication layer of online services relying on certificate-based authentication, such as e-commerce, e-government, online banking, cloud services, and many others. A PKI is an infrastructure based on a hierarchical model, but the use of PKIs in non-hierarchical contexts has exposed them to many types of attacks. Here, we discuss weaknesses exploited in past attacks and we propose a solution based on an original consensus algorithm developed for use on blockchain technology. In this implementation we retain the full functionality around X.509 certificates, i.e., for the triad (server name, server address, X.509 server certificate), and demonstrate a mechanism for obtaining fast consensus. The main properties of the solution are that a consensus may be reached even when not all members of the involved PKI participate in a transaction, and that no advanced trust agreement among PKIs is needed. The proposed solution is able to detect PKI attacks and can distinguish errors from attacks, allowing precise management of anomalies.
Fibrous Material Science: Extensive and Persistent
Authors: Clift Martin J. D.
Published: February 2020

It is my absolute pleasure to take up the position of Editor-in-Chief (EiC) of <ext-link ext-link-type="uri" xlink:href="https://www [...]
Metachronal Swimming with Rigid Arms near Boundaries
Authors: Hayashi Rintaro , Takagi Daisuke
Published: February 2020

Various organisms such as crustaceans use their appendages for locomotion. If they are close to a confining boundary then viscous as opposed to inertial effects can play a central role in governing the dynamics. To study the minimal ingredients needed for swimming without inertia, we built an experimental system featuring a robot equipped with a pair of rigid slender arms with negligible inertia. Our results show that directing the arms to oscillate about the same time-averaged orientation produces no net displacement of the robot each cycle, regardless of any phase delay between the oscillating arms. The robot is able to swim if the arms oscillate asynchronously around distinct orientations. The measured displacement over time matches well with a mathematical model based on slender-body theory for Stokes flow. Near a confining boundary, the robot with no net displacement every cycle showed similar behavior, while the swimming robot increased in speed closer to the boundary.
Breaking the Kolmogorov Barrier in Model Reduction of Fluid Flows
Authors: Ahmed Shady E. , San Omer
Published: February 2020

Turbulence modeling has been always a challenge, given the degree of underlying spatial and temporal complexity. In this paper, we propose the use of a partitioned reduced order modeling (ROM) approach for efficient and effective approximation of turbulent flows. A piecewise linear subspace is tailored to capture the fine flow details in addition to the larger scales. We test the partitioned ROM for a decaying two-dimensional (2D) turbulent flow, known as 2D Kraichnan turbulence. The flow is initiated using an array of random vortices, corresponding to an arbitrary energy spectrum. We show that partitioning produces more accurate and stable results than standard ROM based on a global application of modal decomposition techniques. We also demonstrate the predictive capability of partitioned ROM through an energy spectrum analysis, where the recovered energy spectrum significantly converges to the full order model’s statistics with increased partitioning. Although the proposed approach incurs increased memory requirements to store the local basis functions for each partition, we emphasize that it permits the construction of more compact ROMs (i.e., of smaller dimension) with comparable accuracy, which in turn significantly reduces the online computational burden. Therefore, we consider that partitioning acts as a converter which reduces the cost of online deployment at the expense of offline and memory costs. Finally, we investigate the application of closure modeling to account for the effects of modal truncation on ROM dynamics. We illustrate that closure techniques can help to stabilize the results in the inertial range, but over-stabilization might take place in the dissipative range.
Cascading Dynamics of the Hydrologic Cycle in California Explored through Observations and Model Simulations
Authors: Massoud Elias , Turmon Michael , Reager John , Hobbs Jonathan , Liu Zhen , David Cédric H.
Published: February 2020

As drought occurs in a region it can have cascading effects through the water cycle. In this study, we explore the temporal co-evolution of various components of the hydrologic cycle in California from 2002 to 2018. We combine information from the Gravity Recovery and Climate Experiment (GRACE) satellites, the North American Land Data Assimilation System (NLDAS) suite of models, and the California Department of Water Resources (DWR) reservoir levels to analyze dynamics of Total Water Storage (TWS), soil moisture, snow pack, large reservoir storage, and ultimately, groundwater. For TWS, a trend of −2 cm/yr is observed during the entire time period of our analysis; however, this rate increases to about −5 cm/yr during drought periods (2006−2010 and 2012−2016). Results indicate that the majority of the loss in TWS is caused by groundwater depletion. Using proper error accounting, we are able to identify the start, the peak, and the ending of the drought periods for each individual water state variable in the study domain. We show that snow and soil moisture are impacted earlier and recover faster than surface water and groundwater. The annual and year-to-year dynamics shown in our results portray a clear cascading effect of the hydrologic cycle on the scale of 8−16 months.
Somatic Narratives about Illness. Biometric Visualization of Diseased and Disabled Bodies in Art and Science Projects
Authors: Twardoch-Raś Ewelina
Published: February 2020

This article proposes investigating how the problem of chronic and deadly diseases and bodily injuries is explored in selected contemporary artistic projects based on biometric technologies and medical imaging. All of the projects that will be analysed use specific medical tools and methods (e.g., roentgenography or bio-tracking) to provide detailed, affective images of disability and illness. Nonetheless, these projects were created as pieces of art that combine visual and verbal elements: photographs, collages, and other illustrated stories (e.g., “biometric diaries” or open-source art). On the one hand, they show the “inner” and often invisible face of illness and suffering, but on the other hand they also raise questions related to algorithmic reductionism and politicization of such forms of representation of disease. This article will focus on artistic projects created by Diane Covert, Salvatore Iaconesi and Laurie Frick. It refers to the ‘ethos of health’ and the conception of ethopolitics (Nicolas Rose) to show the place in contemporary biopolitical society of illness (Thomas Lemke), which can be seen as an exceptional form of the body’s condition. Moreover, it considers the problem of the politicization of the biological body and affective experiences (Britta Timm Knudsen and Carsten Stage) and the category of untold histories explored by Joanne Garde-Hansen and Kristyn Gorton.
Market Orientation and Marketing Innovation Activities in the Czech Manufacturing Sector
Authors: Vokoun Marek , Píchová Romana
Published: February 2020

Market competition drives organizations to higher efficiency. This paper analyses the relationship between the prevailing organization’s market orientation and marketing innovation activities. The sample of organizations consists of business enterprises from the manufacturing sector in the Czech economy. Data come from the Community Innovation Survey in 2014 and are analyzed using the innovation process econometric modeling. This innovation survey covers the period of a 3 year J-curve of real GDP growth. Czechia is one of the most open economies in the world and has one of the largest shares of exports and imports to GDP. This paper evaluates four types of marketing innovation activities (design, pricing, placing and promotion methods) at the enterprise level as a factor of marketing capability. The analyzed sample consists of observations about new-to-the-market innovators and enterprises that did not engage in new-to-the-market innovation activities in the last three years. The second group are considered to be lower-level innovators, i.e., adaptors to technological change. This paper explores the relationship between local, national, European and World market orientation in addition to an enterprise’s marketing innovation activities. The results suggest that not all types of marketing innovations are dependent on market orientation, while some have indirect positive and negative effects. Feedback and the future effects of marketing innovation activities are present at the enterprise level. Results also suggest that the marketing innovations of innovators form the manufacturing sector while they are dependent upon the strategies of enterprises to enter new geographical markets and gain the motivation to unlock new (hidden) demand.
Modeling the Optimal Baseline for a Spaceborne Bistatic SAR System to Generate DEMs
Authors: Li Shijin , Zhang Shubi , Li Tao , Gao Yandong , Chen Qianfu , Zhang Xiang
Published: February 2020

Interferometric synthetic aperture radar (InSAR) is one of the best methods for obtaining digital elevation models (DEMs). However, the problem of the uncertainty of DEM accuracy affected by the perpendicular baseline still persists, which should be as long as possible to ensure the sensitivity of the phase to the height measurement, and as small as possible to ensure a high spatial coherence. Moreover, the baseline configuration design of bistatic SAR system lacks a more detailed model for reference to generate high-precision DEM. Therefore, in this paper, the optimal baseline is modeled to maximize the accuracy of height measurement. First, we analyze the influence of system parameters on the height measurement accuracy, and a propagation model from the parameter estimation error to the elevation error is derived. Then, the phase unwrapping error (PUE) that considers the spatial baseline coherence, terrain slope and phase unwrapping effectiveness is modeled and analyzed after interferometric phase simulation and adaptive unscented Kalman filter phase unwrapping. Combining the relationship between the height error and the PUE, the optimal baseline model is obtained by statistical analysis. Finally, weighted averages are used to calculate the average slope of the complex terrain and the validity and reliability of the proposed optimal baseline model are verified by two examples of complex terrains with uniformly and nonuniformly distributed positive and negative slope angles. Moreover, the optimal baseline ranges of different terrain types are also derived for reference.
Research on an Urban Building Area Extraction Method with High-Resolution PolSAR Imaging Based on Adaptive Neighborhood Selection Neighborhoods for Preserving Embedding
Authors: Cheng Bo , Cui Shiai , Ma Xiaoxiao , Liang Chenbin
Published: February 2020

Feature extraction of an urban area is one of the most important directions of polarimetric synthetic aperture radar (PolSAR) applications. A high-resolution PolSAR image has the characteristics of high dimensions and nonlinearity. Therefore, to find intrinsic features for target recognition, a building area extraction method for PolSAR images based on the Adaptive Neighborhoods selection Neighborhood Preserving Embedding (ANSNPE) algorithm is proposed. First, 52 features are extracted by using the Gray level co-occurrence matrix (GLCM) and five polarization decomposition methods. The feature set is divided into 20 dimensions, 36 dimensions, and 52 dimensions. Next, the ANSNPE algorithm is applied to the training samples, and the projection matrix is obtained for the test image to extract the new features. Lastly, the Support Vector machine (SVM) classifier and post processing are used to extract the building area, and the accuracy is evaluated. Comparative experiments are conducted using Radarsat-2, and the results show that the ANSNPE algorithm could effectively extract the building area and that it had a better generalization ability; the projection matrix is obtained using the training data and could be directly applied to the new sample, and the building area extraction accuracy is above 80%. The combination of polarization and texture features provide a wealth of information that is more conducive to the extraction of building areas.
Propolis Consumption Reduces Nosema ceranae Infection of European Honey Bees (Apis mellifera)
Authors: Mura Alessandra , Pusceddu Michelina , Theodorou Panagiotis , Angioni Alberto , Floris Ignazio , Paxton Robert J. , Satta Alberto
Published: February 2020

Nosema ceranae is a widespread obligate intracellular parasite of the ventriculus of many species of honey bee (Apis), including the Western honey bee Apis mellifera, in which it may lead to colony death. It can be controlled in A. mellifera by feeding the antibiotic fumagillin to a colony, though this product is toxic to humans and its use has now been banned in many countries, so in beekeeping, there exists a need for alternative and safe products effective against N. ceranae. Honeybees produce propolis from resinous substances collected from plants and use it to protect their nest from parasites and pathogens; propolis is thought to decrease the microbial load of the hive. We hypothesized that propolis might also reduce N. ceranae infection of individual bees and that they might consume propolis as a form of self-medication. To test these hypotheses, we evaluated the effects of an ethanolic extract of propolis administered orally on the longevity and spore load of experimentally N. ceranae-infected worker bees and also tested whether infected bees were more attracted to, and consumed a greater proportion of, a diet containing propolis in comparison to uninfected bees. Propolis extracts and ethanol (solvent control) increased the lifespan of N. ceranae-infected bees, but only propolis extract significantly reduced spore load. Our propolis extract primarily contained derivatives of caffeic acid, ferulic acid, ellagic acid and quercetin. Choice, scan sampling and food consumption tests did not reveal any preference of N. ceranae-infected bees for commercial candy containing propolis. Our research supports the hypothesis that propolis represents an effective and safe product to control N. ceranae but worker bees seem not to use it to self-medicate when infected with this pathogen.
An Animal Study to Compare Hepatoprotective Effects Between Fermented Rice Bran and Fermented Rice Germ and Soybean in a Sprague-Dawley Rat Model of Alcohol-Induced Hepatic Injury
Authors: Ahn Hee-Young , Cho Young-Su
Published: February 2020

We compared hepatoprotective effects between fermented rice bran (FRB) and fermented rice germ and soybean (FRS) in a Sprague-Dawley (SD) rat model of alcohol-induced hepatic injury (AIHI). To establish an SD rat model of AIHI, the SD rats were given 30% ethanol or water without ethanol treatment. Then, they were given 30% ethanol followed by FRB or FRS at concentrations of 15% or 30%. Our results indicate that the FRB might be more effective in lowering serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), malondialdehyde (MDA) levels in the serum and liver mitochondria, serum triglyceride levels and ALDH levels at a concentration of 15%, serum levels of lactate dehydrogenase (LDH), GSH levels at a concentration of 30% and MDA levels in the liver homogenate and microsome, and hepatic triglyceride levels at both concentrations as compared with the FRS. It can therefore be concluded that FRB might also be considered as an alternative to FRS in improving the AIHI.
Relationship between Sunspot Numbers and Mean Annual Precipitation: Application of Cross-Wavelet Transform—A Case Study
Authors: Nazari-Sharabian Mohammad , Karakouzian Moses
Published: February 2020

Observations show that the Sun, which is the primary source of energy for the Earth’s climate system, is a variable star. In order to understand the influence of solar variability on the Earth’s climate, knowledge of solar variability and solar–terrestrial interactions is required. Knowledge of the Sun’s cyclic behavior can be used for future prediction purposes on Earth. In this study, the possible connection between sunspot numbers (SSN) as a proxy for the 11-year solar cycle and mean annual precipitation (MAP) in Iran were investigated, with the motivation of contributing to the controversial issue of the relationship between SSN and MAP. Nine locations throughout Iran were selected, representing different climatic conditions in the country. Cross-wavelet transform (XWT) analysis was employed to investigate the temporal relationship between cyclicities in SSN and MAP. Results indicated that a distinct 8–12-year correlation exists between the two time series of SSN and MAP, and peaks in precipitation mostly occur one to three years after the SSN maxima. The findings of this study can be beneficial for policymakers, to consider future potential droughts and wet years based on sunspot activities, so that water resources can be more properly managed.
Effect of Progressive Fatigue on Session RPE
Authors: Fusco Andrea , Sustercich William , Edgerton Keegan , Cortis Cristina , Jaime Salvador J. , Mikat Richard P. , Porcari John P. , Foster Carl
Published: February 2020

Rating of perceived exertion (RPE) and session RPE (sRPE) are reliable tools for predicting exercise intensity and are alternatives to more technological and physiological measurements, such as blood lactate (HLa) concentration, oxygen consumption and heart rate (HR). As sRPE may also convey some insights into accumulated fatigue, the purpose of this study was to examine the effects of progressive fatigue in response to heavier-than-normal training on sRPE, with absolute training intensity held constant, and determine its validity as marker of fatigue. Twelve young adults performed eight interval workouts over a two-week period. The percentage of maximal HR (%HRmax), HLa, RPE and sRPE were measured for each session. The HLa/RPE ratio was calculated as an index of fatigue. Multilevel regression analysis showed significant differences for %HRmax (p = 0.004), HLa concentration (p = 0.0001), RPE (p < 0.0001), HLa/RPE ratio (p = 0.0002) and sRPE (p < 0.0001) across sessions. Non-linear regression analysis revealed a very large negative relationship between HLa/RPE ratio and sRPE (r = −0.70, p < 0.0001). These results support the hypothesis that sRPE is a sensitive tool that provides information on accumulated fatigue, in addition to training intensity. Exercise scientists without access to HLa measurements may now be able to gain insights into accumulated fatigue during periods of increased training by using sRPE.
The Effects of Using Partial or Uncorrected Correlation Matrices When Comparing Network and Latent Variable Models
Authors: McFarland Dennis
Published: February 2020

Network models of the WAIS-IV based on regularized partial correlation matrices have been reported to outperform latent variable models based on uncorrected correlation matrices. The present study sought to compare network and latent variable models using both partial and uncorrected correlation matrices with both types of models. The results show that a network model provided better fit to matrices of partial correlations but latent variable models provided better fit to matrices of full correlations. This result is due to the fact that the use of partial correlations removes most of the covariance common to WAIS-IV tests. Modeling should be based on uncorrected correlations since these represent the majority of shared variance between WAIS-IV test scores.
Selective Laser Melting: Materials and Applications
Authors: Prashanth Konda Gokuldoss
Published: February 2020

Additive manufacturing (AM) is one of the emerging manufacturing techniques of immense engineering and scientific importance and is regarded as the technique of the future [...]
Collective Action Dilemma after China’s Forest Tenure Reform: Operationalizing Forest Devolution in a Rapidly Changing Society
Authors: Yiwen Zhang , Kant Shashi , Long Hexing
Published: February 2020

Devolution is a promising tool to enhance forest management. The literature has discussed many factors that affect the outcomes of forest devolution policies; however, insufficient attention has been paid to the role of exogenous socio-economic changes. Using the longitudinal case study method, we focus on how socio-economic changes affect the effectiveness of forest devolution policies using a case from Southeast China. We find that in this case, although forest devolution succeeded in granting farmers sufficient forest rights, it failed to incentivize farmers to contribute to managing forests because of the dramatic changes in socio-economic contexts. Economic development and outmigration reduced farmers’ dependence on forest income, elevated the costs of silvicultural operations, and posed market risks, thereby reducing farmers’ enthusiasm about managing forests; outmigration also weakened community leadership and impeded the collective action of making forest investments. Eventually, socio-economic changes compromised the positive stimulus caused by forest devolution and contributed to the collective action dilemma of managing forests after the reform. We argue that operationalizing forest devolution in developing countries needs to consider the exogenous socio-economic changes that may enhance or counteract the effects of devolution policies, and that more autonomy should be granted to communities to make policies adaptative to their local socio-economic dynamics.
Modeling Y-Linked Pedigrees through Branching Processes
Authors: González Miguel , Gutiérrez Cristina , Martínez Rodrigo
Published: February 2020

A multidimensional two-sex branching process is introduced to model the evolution of a pedigree originating from the mutation of an allele of a Y-linked gene in a monogamous population. The study of the extinction of the mutant allele and the analysis of the dominant allele in the pedigree is addressed on the basis of the classical theory of multi-type branching processes. The asymptotic behavior of the number of couples of different types in the pedigree is also derived. Finally, using the estimates of the mean growth rates of the allele and its mutation provided by a Gibbs sampler, a real Y-linked pedigree associated with hearing loss is analyzed, concluding that this mutation will persist in the population although without dominating the pedigree.
The Marine-Derived Triterpenoid Frondoside A Inhibits Thrombus Formation
Authors: Ampofo Emmanuel , Später Thomas , Nalbach Lisa , Menger Michael D. , Laschke Matthias W.
Published: February 2020

Background: The marine-derived triterpenoid frondoside A inhibits the phosphatidylinositol-3-kinase (PI3K) pathway in cancer cells. Because this pathway is also crucially involved in platelet activation, we studied the effect of frondoside A on thrombus formation. Methods: Frondoside A effects on platelet viability, surface adhesion molecule expression, and intracellular signaling were analyzed by flow cytometry and Western blot. The effect of frondoside A was analyzed by photochemically induced thrombus formation in the mouse dorsal skinfold chamber model and by tail vein bleeding. Results: Concentrations of up to 15 µM frondoside A did not affect the viability of platelets, but reduced their surface expression of P-selectin (CD62P) and the activation of glycoprotein (GP)IIb/IIIa after agonist stimulation. Additional mechanistic analyses revealed that this was mediated by downregulation of PI3K-dependent Akt and extracellular-stimuli-responsive kinase (ERK) phosphorylation. Frondoside A significantly prolonged the complete vessel occlusion time in the mouse dorsal skinfold chamber model of photochemically induced thrombus formation and also the tail vein bleeding time when compared to vehicle-treated controls. Conclusion: Our findings demonstrated that frondoside A inhibits agonist-induced CD62P expression and activation of GPIIb/IIIa. Moreover, frondoside A suppresses thrombus formation. Therefore, this marine-derived triterpenoid may serve as a lead compound for the development of novel antithrombotic drugs.
Investigating the Antiparasitic Potential of the Marine Sesquiterpene Avarone, Its Reduced Form Avarol, and the Novel Semisynthetic Thiazinoquinone Analogue Thiazoavarone
Authors: Imperatore Concetta , Gimmelli Roberto , Persico Marco , Casertano Marcello , Guidi Alessandra , Saccoccia Fulvio , Ruberti Giovina , Luciano Paolo , Aiello Anna , Parapini Silvia , Avunduk Sibel , Basilico Nicoletta , Fattorusso Caterina , Menna Marialuisa
Published: February 2020

The chemical analysis of the sponge Dysidea avara afforded the known sesquiterpene quinone avarone, along with its reduced form avarol. To further explore the role of the thiazinoquinone scaffold as an antiplasmodial, antileishmanial and antischistosomal agent, we converted the quinone avarone into the thiazinoquinone derivative thiazoavarone. The semisynthetic compound, as well as the natural metabolites avarone and avarol, were pharmacologically investigated in order to assess their antiparasitic properties against sexual and asexual stages of Plasmodium falciparum, larval and adult developmental stages of Schistosoma mansoni (eggs included), and also against promastigotes and amastigotes of Leishmania infantum and Leishmania tropica. Furthermore, in depth computational studies including density functional theory (DFT) calculations were performed. A toxic semiquinone radical species which can be produced starting both from quinone- and hydroquinone-based compounds could mediate the anti-parasitic effects of the tested compounds.
Synthesis and Biological Evaluation of Four New Ricinoleic Acid-Derived 1-O-alkylglycerols
Authors: Momha René , Kuete Victor , Pagès Jean-Marie , Pegnyemb Dieudonné , Mosset Paul
Published: February 2020

A series of novel substituted 1-O-alkylglycerols (AKGs) containing methoxy (8), gem-difluoro (9), azide (10) and hydroxy (11) group at 12 position in the alkyl chain were synthesized from commercially available ricinoleic acid (12). The structures of these new synthesized AKGs were established by NMR experiments as well as from the HRMS and elementary analysis data. The antimicrobial activities of the studied AKGs 8–11 were evaluated, respectively, and all compounds exhibited antimicrobial activity to different extents alone and also when combined with some commonly used antibiotics (gentamicin, tetracycline, ciprofloxacin and ampicillin). AKG 11 was viewed as a lead compound for this series as it exhibited significantly higher antimicrobial activity than compounds 8–10.
The Biological and Chemical Diversity of Tetramic Acid Compounds from Marine-Derived Microorganisms
Authors: Jiang Minghua , Chen Senhua , Li Jing , Liu Lan
Published: February 2020

Tetramic acid (pyrrolidine-2,4-dione) compounds, isolated from a variety of marine and terrestrial organisms, have attracted considerable attention for their diverse, challenging structural complexity and promising bioactivities. In the past decade, marine-derived microorganisms have become great repositories of novel tetramic acids. Here, we discuss the biological activities of 277 tetramic acids of eight classifications (simple 3-acyl tetramic acids, 3-oligoenoyltetramic acids, 3-decalinoyltetramic acid, 3-spirotetramic acids, macrocyclic tetramic acids, N-acylated tetramic acids, α-cyclopiazonic acid-type tetramic acids, and other tetramic acids) from marine-derived microbes, including fungi, actinobacteria, bacteria, and cyanobacteria, as reported in 195 research studies up to 2019.
Understanding the Performance of a Novel Direct Compression Excipient Comprising Roller Compacted Chitin
Authors: Abu Fara Deeb , Al-Hmoud Linda , Rashid Iyad , Chowdhry Babur Z. , Badwan Adnan
Published: February 2020

Chitin has been investigated in the context of finding new excipients suitable for direct compression, when subjected to roller compaction. Ball milling was concurrently carried out to compare effects from different energy or stress-inducing techniques. Samples of chitin powders (raw, processed, dried and humidified) were compared for variations in morphology, X-ray diffraction patterns, densities, FT-IR, flowability, compressibility and compactibility. Results confirmed the suitability of roller compaction to convert the fluffy powder of raw chitin to a bulky material with improved flow. X-ray powder diffraction studies showed that, in contrast to the high decrease in crystallinity upon ball milling, roller compaction manifested a slight deformation in the crystal lattice. Moreover, the new excipient showed high resistance to compression, due to the high compactibility of the granules formed. This was correlated to the significant extent of plastic deformation compared to the raw and ball milled forms of chitin. On the other hand, drying and humidification of raw and processed materials presented no added value to the compressibility and compactibility of the directly compressed excipient. Finally, compacted chitin showed direct compression similarity with microcrystalline cellulose when formulated with metronidazole (200 mg) without affecting the immediate drug release action of the drug.
Preliminary Results of an Exercise Program After Laparoscopic Resective Colorectal Cancer Surgery in Non-Metastatic Adenocarcinoma: A Pilot Study of a Randomized Control Trial
Authors: Mascherini Gabriele , Ringressi Maria Novella , Castizo-Olier Jorge , Badicu Georgian , Irurtia Alfredo , Stefani Laura , Galanti Giorgio , Taddei Antonio
Published: February 2020

Background and objectives: Performing physical exercise after a colorectal cancer diagnosis is associated with lower mortality related to the tumor itself. In order to improve physical recovery after elective surgery, there are no specific exercise protocols after discharge from the hospital. The purpose of this study is to show the preliminary results of an exercise program after colorectal cancer surgery. Materials and Methods: Six patients with non-metastatic colorectal adenocarcinoma addressed to respective laparoscopic were randomly assigned to a mixed supervised/home-based exercise program for six months and compared to a control group without exercise. To assess the effectiveness of the program, functional and body composition parameters were evaluated. Results: Three months after surgery, the exercise group increased flexibility (p <0.01, ES = 0.33), strength of lower limbs (p <0.01, ES = 0.42) and aerobic capacity (p <0.01, ES = 0.28). After surgery, the six patients experienced a significant reduction in body mass index (BMI) and free fat mass. More specifically, fat mass reached the lowest values, with a concomitant increase in cell mass after six months (p <0.01, ES = 0.33). This did not occur in the control group. Conclusions: Colorectal cancer treatment induces a reduction in physical function, particularly during the first six months after treatment. A mixed exercise approach appears promising in countering this process after colorectal cancer surgery.
Hybrid Phosphate-Alumina Iron-Based Core-Shell Soft Magnetic Composites Fabricated by Sol-Gel Method and Ball Milling Method
Authors: Pan Yifan , Qian Liwei , Wang Xiang , Peng Jingguang , Lu Wei
Published: February 2020

Novel Fe-based soft magnetic composites (SMCs) with hybrid phosphate-alumina layers were prepared by both sol–gel and ball-milling methods. The effects of the fabrication methods and the addition of Al2O3 particles on the microstructure and the soft magnetic performance of SMCs were studied. The formation of the hybrid phosphate-Al2O3 shell not only leads to the decrease of the total core loss, but also results in the reduction of the permeability and saturation magnetization. However, the degree of decrease caused by the different methods were not identical. The sample with 8% Al2O3 prepared by the sol–gel method showed the best magnetic performance, exhibiting a high-amplitude permeability (μa) of 85.14 and a low total core loss (Ps) of 202.3 W/kg at 50 mT and 100 kHz. The hysteresis loss factor and the eddy current loss factor were obtained by loss separation. The results showed that the samples with the same Al2O3 content prepared by different methods exhibited almost the same total core loss. However, the contribution of the hysteresis loss and the eddy current loss showed an obvious difference in behavior because of the change of the particle shapes and the refinement of the particle size during the ball-milling process.
Study of the Environmental Implications of Using Metal Powder in Additive Manufacturing and Its Handling
Authors: Arrizubieta Jon Iñaki , Ukar Olatz , Ostolaza Marta , Mugica Arantza
Published: February 2020

Additive Manufacturing, AM, is considered to be environmentally friendly when compared to conventional manufacturing processes. Most researchers focus on resource consumption when performing the corresponding Life Cycle Analysis, LCA, of AM. To that end, the sustainability of AM is compared to processes like milling. Nevertheless, factors such as resource use, pollution, and the effects of AM on human health and society should be also taken into account before determining its environmental impact. In addition, in powder-based AM, handling the powder becomes an issue to be addressed, considering both the operator´s health and the subsequent management of the powder used. In view of these requirements, the fundamentals of the different powder-based AM processes were studied and special attention paid to the health risks derived from the high concentrations of certain chemical compounds existing in the typically employed materials. A review of previous work related to the environmental impact of AM is presented, highlighting the gaps found and the areas where deeper research is required. Finally, the implications of the reuse of metallic powder and the procedures to be followed for the disposal of waste are studied.
Optical Trapping and Manipulating with a Silica Microring Resonator in a Self-Locked Scheme
Authors: Ho Victor W. L. , Chang Yao , Liu Yang , Zhang Chi , Li Yuhua , Davidson Roy R. , Little Brent E. , Wang Guanghui , Chu Sai T.
Published: February 2020

Based on the gradient force of evanescent waves in silica waveguides and add-drop micro-ring resonators, the optical trapping and manipulation of micro size particles is demonstrated in a self-locked scheme that maintains the on-resonance system even if there is a change in the ambient temperature or environment. The proposed configuration allows the trapping of particles in the high Q resonator without the need for a precise wavelength adjustment of the input signal. On the one hand, a silicon dioxide waveguide having a lower refractive index and relatively larger dimensions facilitates the coupling of the laser with a single-mode fiber. Furthermore, the experimental design of the self-locked scheme reduces the sensitivity of the ring to the environment. This combination can trap the micro size particles with a high stability while manipulating them with high accuracy.
Salmonella Extracellular Polymeric Substances Modulate Innate Phagocyte Activity and Enhance Tolerance of Biofilm-Associated Bacteria to Oxidative Stress
Authors: Hahn Mark M. , Gunn John S.
Published: February 2020

Salmonella enterica serovar Typhi causes 14.3 million acute cases of typhoid fever that are responsible for 136,000 deaths each year. Chronic infections occur in 3%–5% of those infected and S. Typhi persists primarily in the gallbladder by forming biofilms on cholesterol gallstones, but how these bacterial communities evade host immunity is not known. Salmonella biofilms produce several extracellular polymeric substances (EPSs) during chronic infection, which are hypothesized to prevent pathogen clearance either by protecting biofilm-associated bacteria from direct humoral attack or by modulating innate phagocyte interaction with biofilms. Using wild-type and EPS-deficient planktonic and biofilm Salmonella, the direct attack hypothesis was tested by challenging biofilms with human serum and antimicrobial peptides. Biofilms were found to be tolerant to these molecules, but these phenotypes were independent of the tested EPSs. By examining macrophage and neutrophil responses, new roles for biofilm-associated capsular polysaccharides and slime polysaccharides were identified. The S. Typhi Vi antigen was found to modulate innate immunity by reducing macrophage nitric oxide production and neutrophil reactive oxygen species (ROS) production. The slime polysaccharides colanic acid and cellulose were found to be immune-stimulating and represent a key difference between non-typhoidal serovars and typhoidal serovars, which do not express colanic acid. Furthermore, biofilm tolerance to the exogenously-supplied ROS intermediates hydrogen peroxide (H2O2) and hypochlorite (ClO−) indicated an additional role of the capsular polysaccharides for both serovars in recalcitrance to H2O2 but not ClO−, providing new understanding of the stalemate that arises during chronic infections and offering new directions for mechanistic and clinical studies.
Cuminal Inhibits Trichothecium roseum Growth by Triggering Cell Starvation: Transcriptome and Proteome Analysis
Authors: Zhang Zhong , Zhang Wenting , Bi Yang , Han Ye , Zong Yuanyuan , Prusky Dov
Published: February 2020

Trichothecium roseum is a harmful postharvest fungus causing serious damage, together with the secretion of insidious mycotoxins, on apples, melons, and other important fruits. Cuminal, a predominant component of Cuminum cyminum essential oil has proven to successfully inhibit the growth of T. roseum in vitro and in vivo. Electron microscopic observations revealed cuminal exposure impaired the fungal morphology and ultrastructure, particularly the plasmalemma. Transcriptome and proteome analysis was used to investigate the responses of T. roseum to exposure of cuminal. In total, 2825 differentially expressed transcripts (1516 up and 1309 down) and 225 differentially expressed proteins (90 up and 135 down) were determined. Overall, notable parts of these differentially expressed genes functionally belong to subcellular localities of the membrane system and cytosol, along with ribosomes, mitochondria and peroxisomes. According to the localization analysis and the biological annotation of these genes, carbohydrate and lipids metabolism, redox homeostasis, and asexual reproduction were among the most enriched gene ontology (GO) terms. Biological pathway enrichment analysis showed that lipids and amino acid degradation, ATP-binding cassette transporters, membrane reconstitution, mRNA surveillance pathway and peroxisome were elevated, whereas secondary metabolite biosynthesis, cell cycle, and glycolysis/gluconeogenesis were down regulated. Further integrated omics analysis showed that cuminal exposure first impaired the polarity of the cytoplasmic membrane and then triggered the reconstitution and dysfunction of fungal plasmalemma, resulting in handicapped nutrient procurement of the cells. Consequently, fungal cells showed starvation stress with limited carbohydrate metabolism, resulting a metabolic shift to catabolism of the cell’s own components in response to the stress. Additionally, these predicaments brought about oxidative stress, which, in collaboration with the starvation, damaged certain critical organelles such as mitochondria. Such degeneration, accompanied by energy deficiency, suppressed the biosynthesis of essential proteins and inhibited fungal growth.