bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlations between Grain Angle Meter Readings and Bending Properties of Mill-Run Southern Pine Lumber
Authors: Anderson Guangmei Cao , Owens Frank C. , Franca Frederico , Ross Robert J. , Shmulsky Rubin
Published: August 2021

Metriguard's grain angle meter (Model 511) measures grain angle in wood by assessing permittivity. This study evaluates the correlations between grain angle meter readings and bending properties of 1,400 kiln-dried 2 by 4 specimens of southern pine (Pinus spp.) lumber and considers its utility for providing supplementary data for predicting the strength of lumber. The results showed that in mill-run lumber, the correlation between grain angle and modulus of rupture (MOR) was −0.420. In addition, in graded lumber, the correlation between grain angle and MOR got progressively stronger as the grade went down. With a few technical modifications, applying this device in a mill production setting could prove useful for supplementing other nondestructive methods for assessing bending strength in lumber.
Perspectives on Ash Wood Utilization and Marketing in Anticipation of Emerald Ash Borer in Minnesota
Authors: Russell Matthew B. , Ring Elizabeth C.
Published: August 2021

The emerald ash borer will likely impact over four million acres of Minnesota's forests in the next 10 years. This study surveyed forest products company representatives and other natural resource professionals to understand their perspectives on the current and future use of ash in wood markets. Survey respondents indicated they were only slightly optimistic that there will be new and emerging ash markets to support the large volume of ash wood potentially available in the next 10 years; however, new technologies such as torrefaction and heat treatments were noted as potential new markets for the species.
Nondestructive Evaluation of Red Oak and White Oak Species
Authors: Turkot Cristian Grecca , Seale Roy Daniel , Entsminger Edward D. , França Frederico José Nistal , Shmulsky Rubin
Published: August 2021

The objective of this article is to evaluate the relationship between the dynamic modulus of elasticity (MOEd), which was obtained with acoustic-based nondestructive testing (NDT) methods, and static bending properties of two domestic hardwood oak species. The mechanical properties were conducted using static modulus of elasticity (MOE) and modulus of rupture (MOR) in radial and tangential directions. Mechanical tests were performed according to ASTM D143 on small clear, defect-free specimens from the two tree species: red oak (Quercus rubra) and white oak (Quercus alba). The MOEd was determined by two NDT methods and three longitudinal vibration methods based on the fast Fourier transform. The destructive strength values obtained in this study were within the expected range for these species. The MOE was best predicted by NDT methods for both species but also had a strong capability to predict MOR.
A Specialized Data Crawler for Cross-Laminated Timber Information Resources
Authors: Thomas Ed , Espinoza Omar , Bora Rahul , Buehlmann Urs
Published: August 2021

The Internet is composed of more than 6.2 billion Web pages and grows larger every day. As the number of links and specialty subject areas grows, it becomes ever more difficult to find pertinent information. For some subject areas, special-purpose data crawlers continually search the Internet for specific information; examples include real estate, air travel, auto sales, and others. The use of such special-purpose data crawlers (i.e., targeted crawlers and knowledge databases) also allows the collection and analysis of agricultural and forestry data. Such single-purpose crawlers can search for hundreds of key words and use machine learning to determine if what is found is relevant. In this article, we examine the design and data return of such a specialty knowledge database and crawler system developed to find information related to cross-laminated timber (CLT). Our search engine uses intelligent software to locate and update pertinent references related to CLT as well as to categorize information with respect to common application and interest areas. At the time of this publication, the CLT knowledge database has cataloged nearly 3,000 publications regarding various aspects of CLT.
Utilization of Ground Peanut Husk as an Alternative Fiber Material for Particleboard
Authors: Newton Jacob Allen , Morrell Jeffery J.
Published: August 2021

The potential for using peanut (Arachis hypogaea) husks as an alternative fiber for particleboard production was examined at five different levels of melamine-urea-formaldehyde resin (MUF). The resulting panels were evaluated for moisture absorption, thickness swell, flexural properties (modulus of rupture [MOR] and modulus of elasticity [MOE]) and internal bond (IB) strength. MOR, MOE and IB values of panels containing ≥6 percent resin met or exceeded American National Standards Institute standards for multiple grades of particleboard although they were weaker than previous reports of commercially produced wood particleboards. Moisture uptake and thickness swell also improved markedly at resin levels >6 percent. The results suggest that peanut husks are an attractive alternative fiber source in combination with the MUF resin system.
Fourier-Transform Infrared Spectroscopy Analysis of the Changes in Chemical Composition of Wooden Components in the Ancient Building of Xichuan Guild Hall
Authors: Yang Yan , Sun He , Li Bin , Wang Aifeng , Zhao Rui , Wang Wei , He Yiming , Yang Shuang , Han Yanxia , Sun Wenye
Published: August 2021

In order to investigate the decay mechanism in red oak (Quercus rubra) and Schima (Schima spp.) wood in the ancient building of Xichuan Guild Hall, the changes in chemical composition were determined using Fourier-Transform Infrared Spectroscopy. The results were as follows: (1) The absorption peak intensities that represented the structural contribution of carbohydrates, and the crystallinity index of the cellulose in the red oak components, decreased noticeably by 55.70 percent in H1039/H1508, and 26.85 percent in H1370/H2900; while those of lignin were increased as a result of the brown rot process. These changes indicated that the brown-rot fungi had stronger degradation effects on hemicellulose and cellulose over lignin. (2) The absorption peak intensities of the carbohydrates (a part of the lignin) and the crystallinity index of the cellulose decreased noticeably by 22.50 percent in H1039/H1508, 25.00 percent in H1508/H1735, and 21.74 percent in H1429/H897 after white rot in the Schima wood components. These findings indicated that not only cellulose and hemicellulose but also lignin were attacked by white-rot fungi. By comparison, the extent of fungal damage in the wood components was lower in the Schima wood components than that in the red oak components.
Influence of Adding Lignin and Wood as Reactive Fillers on the Properties of Lightweight Wood–Polyurethane Composite Foams
Authors: Luo Shupin , Gao Li , Guo Wenjing
Published: August 2021

In this study, bio-based rigid polyurethane (PU) composite foams were prepared by a free-rising method, with the addition of wood particles (10 and 20 weight percent by the foam mass) and kraft lignin (5 and 10 weight percent by the polyol mass) as reactive reinforcing fillers. The resultant PU composites were evaluated for chemical structure, density, morphology, compressive properties, water uptake, and thermal stability. Fourier-transform infrared analysis confirmed the formation of characteristic urethane bonds in all foam samples. The foaming process was slowed down by the incorporation of lignin and wood particles. The apparent density of lignin-incorporated wood–PU composite foam ranged between 77 and 105 g/cm3. Compared with the neat PU foam, addition of wood particle resulted in decreased compressive properties and increased water uptake of the foams, whereas incorporation of lignin had a positive effect on the compressive properties and water resistance. In general, the PU foam sample with the incorporation of only 5 percent lignin (PUL5) exhibited the optimal physical–mechanical properties, with the compressive strength increased by 74 percent and 24-hour water uptake decreased by 28 percent compared with the control PU foam. Thermogravimetric analysis showed that the incorporation of lignin and wood particles did not significantly affect the thermal degradation pattern of foam but rather increased the mass of char residue.
Comparing Wood versus Concrete: An Explorative Study of Municipal Civil Servants' Beliefs About Multistory Building Materials in Finland
Authors: Franzini Florencia , Berghäll Sami , Toppinen Anne , Toivonen Ritva
Published: August 2021

The rising interest in wooden multistory buildings (WMSB) has led to multiple studies investigating how construction professionals perceive different structural frame materials. These investigations, however, exclude viewpoints from public employees (i.e., civil servants), who are central to driving the implementation of WMSB. This study is part of a broader inquiry to examine perceptions from Finnish civil servants who are responsible for municipal land-use planning and development. To this end, a questionnaire applying the theory of planned behavior was designed. Civil servants were asked to evaluate how strongly they believe WMSB possess 16 attributes in comparison to concrete multistory buildings (CMSB). The attributes constitute statements concerning various economic, social, and environmental impacts of multistory buildings, as well as technical properties. Responses (N = 273) indicate that WMSB are believed to possess positive environmental attributes and to support economic development. In contrast, CMSB are regarded to have lower construction and maintenance cost and to be less susceptible to fire. Furthermore, exogenous factors, like demographics, previous experience, and social environments, were significantly correlated to respondents' beliefs. Especially prominent was the relationship between profession and beliefs about technical and environmental attributes. Future research should focus on determining whether the set of attributes assessed in this study are relevant to the implementation of multistory building projects within Finnish municipalities.
Yellow Pine Small Clear Flexural Properties across Five Decades
Authors: França Frederico José Nistal , Shmulsky Rubin , Ratcliff J. Tedrick , Farber Benjamin , Senalik C. Adam , Ross Robert J. , Seale R. Daniel
Published: August 2021

When discussing structural southern yellow pine lumber, questions frequently are asked regarding changes over time. This is a significant area of discussion given that structural lumber properties (i.e., design values) were changed around 2012. Climate change, forest management, genetics, processing, and others are listed among the many possible contributing factors. Of interest are these questions: (1) Are changes in bending properties permanent at some fundamental level, or are they somewhat dynamic and responsive to controllable factors? (2) To what degree have the basic southern pine wood mechanical properties changed over time? Related thereto, this research examines the bending properties of small clear pine specimens from three samples. Sample 1 was pulled from a production-weighted sample of in-grade parent lumber. Sample 2 was pulled from commercially available molding and millwork. Sample 3 was pulled from data from the U.S. Department of Agriculture Forestry Products Laboratory from the early to mid-1960s. The flexural properties of small clear specimens among the three samples showed some statistically significant differences. However, there was no clear trend regarding these differences. These results appear to support the notion that while the variability of pine's flexural properties is significant and that while many changes in forest management and production have occurred over the past five decades, the basic density and bending strength of clear southern pine appear generally stable over time.
Steaming and Heating Dipteryx panamensis Logs from Fast-Grown Plantations: Reduction of Growth Strain and Effects on Quality
Authors: Moya Roger , Tenorio Carolina , Torres Juan David Conde
Published: August 2021

Steaming and heating as pretreatments before log sawing reduce the negative effects of growth strain (GS). The object of this work was to study the reduction of GS in logs of Dipteryx panamensis from a fast-growth plantation using steaming and heating treatments and evaluate the effects on the lumber quality. According to the results, the maximum temperature in the center of the log was approximately 90°C after 24 hours for both treatments. GS decreased after heating and steaming. The average value of GS for three treatments was 2,085.61 microdeformation units (με) before the treatment, decreasing to average value to1,692.14 με after the treatments. This reduction in turn produced a reduction of crook due to sawing measured in logs and semilogs and a decrease in the values and incidence of crook, bow, twist, and split. Similarly, color parameters (L*, a*, and b*) were statistically affected by the treatment, except for parameter L* in sapwood. In general, wood darkening was observed. Lastly, both treatments applied to D. panamensis logs showed few differences in GS, in crook due to sawing measured in logs and semilogs, and in the values and incidence of crook, bow, twist, and split. Therefore, both treatments achieved GS reduction in D. panamensis lumber.
Seventy-five Years of Research in Wood Preservation and Deterioration
Authors: Barnes H. M.
Published: August 2021

Seventy-five years of research in wood protection at the Forest Products Lab at Mississippi State University are described. A history of wood protection is presented along with an overview of the facilities supporting the research. Program objectives are presented along with the personnel responsible for building the program. A brief presentation of research areas is given followed by some program metrics.
Failure Analysis of Bamboo Bolt Connection in Uniaxial Tension by FEM by Considering Fiber Direction
Authors: Ramful Raviduth
Published: August 2021

Full-culm bamboo has been used for millennia in construction. Specific connections are normally required to suit its unique morphology and nonuniform structure. Presently, the use of full-culm bamboo is limited in the construction industry as a result of a lack of information and test standards about the use and evaluation of full-culm connections. This study aims to further explore this area by investigating the failure modes in bamboo bolt connections in uniaxial tension by considering fiber direction in finite element analysis. Three types of bolt configurations of varying permutations, namely, single, dual, and orthogonal, were investigated. An orthotropic material was used as a constitutive model in finite element formulation to capture the inhomogeneity prevailing in bamboo culm. From the strain-field analysis of a hollow-inhomogeneous model representing bamboo, shear-out failure was dominant, as a localized area equivalent to the bolt diameter was affected due to high material orthotropy with high axial strength but weak radial and tangential strength. Bearing failure is assumed to precede shear-out failure at the bolt–bamboo contact interface, as the embedding strength was affected by localized strain concentration. The strain distribution in various bolt arrangements was found to vary between bolted connections of inhomogeneous-hollow geometry of bamboo and the ones of inhomogeneous-solid geometry representing timber. The observation in this study highlights the need for alternative design criteria to specifically assess the damage mechanism in bamboo connections.
Competitiveness of Timber Floor Elements: An Assessment of Structural Properties, Production, Costs, and Carbon Emissions
Authors: Nesheim Sveinung , Malo Kjell Arne , Labonnote Nathalie
Published: August 2021

As long-spanning timber floor elements attempt to achieve a meaningful market share, proof of serviceability continues to be a demanding task as international consensus remains unsettled. Initiatives to improve vibration levels are achievable, but a lack of confidence in the market is resulting in increases in margins for both manufacturers and contractors. State-of-the-art concrete alternatives are offered at less than half the price, and even though timber floors offer reduced completion costs and low carbon emissions, the market is continuously reserved. Cost reductions for timber floor elements to competitive levels must be pursued throughout the product details and in the stages of manufacturing. As new wood products are introduced to the market, solution space is increased to levels that demand computerized optimization models, which require accurate expenditure predictions. To meet this challenge, a method called item-driven activity-based consumption (IDABC) has been developed and presented in this study. The method establishes an accurate relationship between product specifications and overall resource consumption linked to finished manufactured products. In addition to production time, method outcomes include cost distributions, including labor costs, and carbon emissions for both accrued materials and production-line activities. A novel approach to resource estimation linked to assembly friendliness is also presented. IDABC has been applied to a timber component and assembly line operated by a major manufacturer in Norway and demonstrates good agreement with empirical data.
Borate and Quaternary Ammonia Dip Diffusion to Treat Fungal Pathogens of Metrosideros polymorpha Wood
Authors: Hughes Marc A. , Morrell Jeffrey J. , Cappellazzi Jed , Mackey Bruce , Juzwik Jennifer , Keith Lisa M.
Published: August 2021

Rapid Ohia Death is a major concern for the viability of ohia (Metrosideros polymorpha) in Hawaii and has led to restrictions on log movement. The potential for using disodium octaborate tetrahydrate (DOT) and didecyl dimethyl ammonium chloride (DDAC) dip diffusion treatments to control the two causal fungi (Ceratocystis lukuohia and Ceratocystis huliohia) was investigated. A 10 percent boric acid equivalent dip diffusion treatment killed the pathogens in 0.5-cm-thick disks obtained from 4.0- to 5.0-cm-diameter limbs of naturally colonized trees. DOT tended to diffuse more consistently in 50- to 60-cm-long bolts of small (4.0 to 9.0 cm) and large (9.1 to 17.0 cm) diameter healthy ohia compared with those bolts naturally infected by C. lukuohia. Diffusion periods longer than 6 weeks resulted in deeper penetration. Immersion (24 h) of logs (1.3 m long; 9 to 17 cm diameter) from C. lukuohia artificially inoculated trees in two forest locations in a 15 percent DOT/1 percent DDAC solution and storage for 10 weeks before evaluation resulted in incomplete elimination of the pathogen and lower boron concentrations in the inner sapwood than outer. Further investigations are needed to explore using either higher boron concentrations or longer diffusion periods to deliver fungicidal concentrations of boron deeper within the wood matrix.
The Effect of Variables on Laboratory Termite Testing: Part 4—Test Block Species, Size, and Test Photoperiod
Authors: Lindsey G. B. , Amburgey T. L. , Barnes H. M.
Published: August 2021

The objective of this study was to determine the impact on termite feeding of wood sample size and species and test photoperiod in standard tests. Native species (Reticulitermes flavipes) and introduced species (Coptotermes formosanus) were tested in an American Wood-Preservers' Association E1 standard laboratory test. For testing involving treated wood, southern yellow pine was determined to be preferable to spruce based on its treatability and availability. Test blocks of 25 by 25 by 6 mm were deemed adequate for testing, with large blocks presenting difficulty with retrieval of termites to determine mortality and smaller blocks being consumed too rapidly by the termites in the test. Photoperiod comparisons were not significantly different for R. flavipes; however, C. formosanus indicated a preference for 100 percent darkness. Therefore, the recommendation is to maintain tests using each species in a 100 percent dark environment.
Biological Durability of Cross-Laminated Timber— The State of Things
Authors: Udele Kenneth E. , Morrell Jeffrey J. , Sinha Arijit
Published: August 2021

Cross laminated timber (CLT) is a mass timber product that is gaining popularity in construction within North America. CLT is made up of wood, a building material of biological origin. Therefore, these materials are at a risk of decay upon intrusion of moisture, a situation that could lead to loss of confidence in the material. Ensuring durability and optimum performance of building elements throughout their expected service life will require an understanding of the potential for decay and the possible consequences. This paper reviews the various possibilities of moisture intrusion in CLT, their potential effects on the physical and mechanical properties of CLT, and ultimately the associated biological decay risks. The paper concludes by enumerating variables that are critical and should be evaluated to completely understand decay in CLT panels, stemming from a thorough review of previous studies and methods used to evaluate decay in mass timber.
Love It or Leave It: What Do Millennials Really Think of Wood Products?
Authors: Montague Iris , Stout Kassandra , Shmulsky Rubin
Published: August 2021

In the past, the wood products industry has often struggled with effectively marketing products to the public. With the increase of globalization and wood substitutions, the industry may need new ways to attract customers. Targeting younger customers who have recently joined the buyer's market may be a way to increase the industry's market share and customer base. A study was conducted to understand the millennial generation's (individuals born from 1980 to 2000) knowledge and perception of wood products. In 2018, an online survey was distributed to over 1,500 millennial-aged individuals and 1,479 usable survey responses were returned. Results indicate that respondents have a favorable perception of wood products and that there is potential to change uncertain or negative perceptions by providing informative facts about wood products. Approximately 71 percent of millennials indicated paper and pulp to be the most popular wood product, followed by lumber (51%) Responses also showed that 84 percent of respondents perceived wood as beautiful and 54 percent indicated it appealed to their sense of style. In terms of strength and durability, 46 percent of the respondents did not perceive wood to be as strong as steel. They were unaware of cross-laminated timber (74%) and its structural benefits and did not feel it was a safe product to use in tall buildings (54%). Millennial females and all millennials ages 18–20 held particularly stronger attitudes about wood products. The information gained from this research can be valuable when developing strategies to promote products and attract new customers.
GLOBAL OVERVIEW OF HYDROPONICS: NUTRIENT FILM TECHNIQUE
Authors: Silva Marina Galdez de Castro , Hüther Cristina Moll , Ramos Bruno Bernardo , Araújo Patrícia da Silva , Hamacher Leonardo da Silva , Pereira Carlos Rodrigues
Published: August 2021

Hydroponics is a cultivation technique without soil. There are several modalities for the system and among them is the Nutrient Film Technique (NFT), which consists of using channels to circulate a nutrient solution intermittently. Due to the existence of risks of soil and water contamination in metropolitan areas, hydroponics is a potential alternative to conventional production. Therefore, the present work sought to verify the current study of knowledge of the NFT hydroponic system in the international literature and the performance of the countries on it. For this, a bibliographic survey was carried out from 2010 to 2019 on the international research bases Science Direct, Portal de Periódicos da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Scielo using the search terms “Hydroponics” and “Nutrient Film Technique Hydroponics”. An increase in the number of studies was observed in the last four years of the analyzed period, that is, from 2016 to 2019, thus representing an increase in interest in hydroponics, especially the NFT type. This increase may be related to the efficiency and ease of handling this model, gains in productivity and the potential that this technique has for reducing the carbon footprint. Thus, Nutrient Film Technique is of great value in urban agriculture, especially in Brazil – its greatest representative –, with the potential to grow a lot in the future, due to its numerous benefits.
Sabry Musa's Lord of the Spinach Field (1987): A Critique of Post-Colonial Utopianism
Authors: Alkhayat Marwa Essam Eldin Fahmy
Published: August 2021

The present study examines the aesthetic features of Sabry Musa's Lord of the Spinach Field (1987) through Karl-Heinz Bohrer's “Utopia of the Subject” to foreground Homo's quest for a wished-for yet unattainable reality. Post-Colonial Utopianism depicts man's inner turmoil to force an act of willful rethinking to enhance the “anticipatory consciousness” of a better life, a point interrogated within Ernst Bloch's Principle of Hope to propose the concept of the “Not-Yet-Become”: the not realized futuristic reality. Therefore, the interest is in utopia/dystopia historicities as analytical markers of historical inquiry to analyze specific space/time coordinates; post-colonial pitfalls of a technoscience dystopia. As such, the remarkable characteristic of Post-Colonial Utopianism is critique, and “Subjective Utopia” strives to achieve a breach in the teleological ideology of historical structures; thereby, transformation is the central aesthetic strategy of post-colonial critique.
Algorithmic work coordination and workers' voice in the COVID-19 pandemic: The case of Foodora/Lieferando
Authors: Schreyer Jasmin
Published: August 2021

The COVID-19 pandemic exacerbates the conflictual nature of work in the digital platform economy as if it were ignited under a magnifying glass. In this context, this article focuses on the logic of control of algorithmic labour coordination, adopting a qualitative case study approach. In a situation in which the technical infrastructure of online platforms generally impedes labour protests, it examines the case of Lieferando (formerly Foodora) in Germany, where, unusually, the on-demand workforce is employed. It concludes that in this situation, the algorithmic management of Lieferando facilitates labour protests because of a lack of communication between employer and worker. Furthermore, in the COVID-19 pandemic, institutionalised relationships function as a countervailing power to that of the employer, forcing it to act.
To exploit and dispossess: The twofold logic of platform capitalism
Authors: Fagioli Andrea
Published: August 2021

This paper addresses the relation between capital and digital labour in the context of so-called platform capitalism. Based on the taxonomy proposed by A. Casilli - on-demand labour, crowdwork or microwork, and social media labour - I argue that the concept of exploitation is not sufficient to fully account for the logic of platform capitalism, as it only makes up one of its dimensions. The other central dimension is that which targets data capture, which I call, using Harvey's term, ‘dispossession’. Far from proposing a fixed delimitation of the concept of labour, I argue that the two dimensions operate together and, in many cases, it is difficult to isolate them, but they do demand the invention of different political strategies.
Arizona Thoracic Society Supports Mandatory Vaccination of Healthcare Workers
Authors:   Arizona Thoracic Society, Robbins Richard
Published: August 2021

No abstract available. Article truncated after 150 words. I watched much of the past year and a half of the COVID-19 pandemic in horror listening to the TV pundits and politicians argue against wearing masks, receiving vaccinations, and in general, undermining the safety and freedoms of all Americans. Nothing is done to regulate commentator or politician disinformation under the excuse that these pundits have the right of free speech as a fundamental liberty. Fundamental liberties are freedoms the population is entitled to fully enjoy without government intrusion. Nevertheless, the proper exercise of these liberties, taken in conjunction with the need for public order, national security, the preservation of moral values, as well as respect for the rights of one’s fellowman—all of this necessarily entails that some restrictions be placed upon these liberties (1). Only the freedom of thought, conscience and opinion are subject to no real restriction. Each and every person is free to think what he …
Unveiling osteosarcoma responses to DAPT combined with cisplatin by using confocal Raman microscopy
Authors: Li Jie , Li Jing , Wang Haifeng , Qin Jie , Zeng Haishan , Wang Kaige , Wang Shuang
Published: August 2021

The aim of this study was to clarify the dose- and time-dependent effect of the γ-secretase inhibitor (DAPT) combined with cisplatin on osteosarcoma (OS) cells, evaluated by confocal Raman microspectral imaging (CRMI) technology. The intracellular composition significantly changed after combined drug action compared with the sole cisplatin treatment, proving the synergistic effect of DAPT combined with cisplatin on OS cells. The principal component analysis-linear discriminant analysis revealed the main compositional variations by distinguishing spectral characteristics. K-means cluster and univariate imaging were used to visualize the changes in subcellular morphology and biochemical distribution. The results showed that the increase of the DAPT dose and cisplatin treatment time in the combination treatment induced the division of the nucleus in OS cells, and other organelles also showed significant physiological changes compared with the effect of sole cisplatin treatment. After understanding the cellular response to the combined drug treatment at a molecular level, the achieved results provide an experimental fact for developing suitable individualized tumor treatment protocols.
Dimensioning access link capacity for time-varying traffic with mixed packet streams and circuit connections
Authors: Shao Junyi , Zhang Shuai , Sun Weiqiang , Hu Weisheng
Published: August 2021

Access links that connect cloud data centers or enterprise networks to public networks are important parts of the network infrastructure and make up considerable portions of overall network expenditures. When a customer network is connected to an overlaid elastic optical network, determining the capacity of the access link is difficult. Furthermore, access links carry mixed packet streams and circuit connections, each with different performance requirements. Additionally, traffic loads are time-varying and often exhibit diurnal patterns. In this study, we formulate the access link capacity dimensioning problem as an optimization problem with a nested dynamic constraint satisfaction subproblem. Instead of using hard performance measures, such as packet delays and blocking probabilities, we use the probability of fulfillment with regard to different traffic arrival rates as the performance measure and the performance–cost ratio as our optimization objective. Numerical results suggest that a 7.5% to 19.47% cost savings can be achieved if resources are shared between packet streams and circuit connections. And if resource preemptions are allowed, the delay performance for packet streams can be improved by 12% with more frequent preemptions. Our study provides useful insights into the planning and operation of access links.
Polarization-sensitive imaging based on incoherent holography
Authors: Sheng Wei , Liu Youwen , Yang Haoyu , Shi Yaoyao , Wang Jiming
Published: August 2021

The polarization-sensitive imaging technology is proposed based on incoherent holography. The distribution of state of polarization (SoP) of the object light field can be reconstructed by measuring the phase difference and amplitude ratio of two components of the Jones vector on the basis of incoherent self-interference theory and the accurate point spread function (PSF) of the incoherent holographic system. In the analysis of Fresnel diffraction, we develop a new method to greatly simplify the calculation of the accurate PSF by means of imaging property of lens and symbolic mathematics tools. In the recording process, we utilize the automation of phase shift, photography, and synthesization of color hologram to greatly shorten the total recording time of a group of phase-shifted holograms. The experimental results show that the proposed technology can accurately realize polarization-sensitive imaging and it is much simpler for complete linearly polarized light.
Theoretical realization of single-mode fiber integrated metalens for beam collimating
Authors: Ye Huapeng , Sun Qian , Guo Zhenghao , Hou Yang , Wen Feng , Yuan Dong , Qin Fei , Zhou Guofu
Published: August 2021

Optical fiber facet has rapidly emerged as a powerful light-coupling platform for integrating metasurfaces with miniaturized footprint and multifarious functionalities, through direct lithographic patterning or decal transfer. However, the fiber integrated metasurfaces investigated so far have been usually limited to high refractive index (RI) materials, thus leading to severe impedance mismatch at the fiber/metasurface interface and low efficiency. Here we report a single-mode fiber (SMF) integrated metalens based on low-RI material. We theoretically show that the highly divergent beam at the cleaved SMF is fully collimated by the metalens consisting of elliptical nanoposts with uniform height but varied width and length. The spatial wavefront of the transmitted light at the end facet of the light waveguide is properly modulated by the metasurface while maintaining an efficiency beyond 95% in the simulation. This study demonstrates a roadmap to design highly efficient SMF integrated metasurface based on low-RI material and may find applications in biomedical and optical imaging.
CDDA: extension and analysis of the discrete dipole approximation for chiral systems
Authors: Rosales S. A. , Albella P. , González F. , Gutiérrez Y. , Moreno F.
Published: August 2021

Discrete dipole approximation (DDA) is a computational method broadly used to solve light scattering problems. In this work, we propose an extension of DDA that we call Chiral-DDA (CDDA), to study light-chiral matter interactions with the capability of describing the underlying physics behind. Here, CDDA is used to solve and analyze the interaction of a nanoantenna (either metallic or dielectric) with a chiral molecule located in its near field at different positions. Our method allowed to relate near field interactions with far field spectral response of the system, elucidating the role that the nanoantenna electric and magnetic polarizabilities play in the coupling with a chiral molecule. In general, this is not straightforward with other methods. We believe that CDDA has the potential to help researchers revealing some of the still unclear mechanisms responsible for the chiral signal enhancements induced by nanoantennas.
Quadratic phase coding for SNR improvement in time-expanded phase-sensitive OTDR
Authors: Soriano-Amat Miguel , Martins Hugo F. , Durán Vicente , Martin-Lopez Sonia , Gonzalez-Herraez Miguel , Fernández-Ruiz María R.
Published: August 2021

Time-expanded phase-sensitive optical time-domain reflectometry (

T
E

−
Φ

O
T
D
R

) is a dual-comb-based distributed optical fiber sensing technique capable of providing centimeter scale resolution while maintaining a remarkably low (MHz) detection bandwidth. Random spectral phase coding of the dual combs involved in the fiber interrogation process has been proposed as a means of increasing the signal-to-noise ratio (SNR) of the sensor. In this Letter, we present a specific spectral phase coding methodology capable of further enlarging the SNR of

T
E

−
Φ

O
T
D
R

. This approach is based on the use of a quadratic spectral phase to precisely control the peak power of the comb signals. As a result, an SNR improvement of up to 8 dB has been experimentally attained with respect to that based on the random phase coding previously reported.
Efficient four-way vertical coupler array for chip-scale space-division-multiplexing applications
Authors: Luo Haozhi , Chen Lifeng , Yu Siyuan , Cai Xinlun
Published: August 2021

We propose and demonstrate a three-dimensional nano-printed four-channel vertical coupler array on the silicon-on-insulator platform for efficient chip-to-multicore fiber coupling. The proposed structure provides less than 1 dB loss in a single lane and around 2–4 dB loss in multicore fiber coupling, over 100 nm 1 dB bandwidth, and large 1 dB misalignment tolerances of more than 5 µm in the

x
y

plane and 20 µm in the

z

direction. The device shows great promise for photonic integrated devices for space-division-multiplexing technology based on multicore fiber.
Integration of a physiologically-based pharmacokinetic model with a whole-body, organ-resolved genome-scale model for characterization of ethanol and acetaldehyde metabolism
Authors: Zhu Leo , Pei William , Thiele Ines , Mahadevan Radhakrishnan
Published: August 2021

Ethanol is one of the most widely used recreational substances in the world and due to its ubiquitous use, ethanol abuse has been the cause of over 3.3 million deaths each year. In addition to its effects, ethanol’s primary metabolite, acetaldehyde, is a carcinogen that can cause symptoms of facial flushing, headaches, and nausea. How strongly ethanol or acetaldehyde affects an individual depends highly on the genetic polymorphisms of certain genes. In particular, the genetic polymorphisms of mitochondrial aldehyde dehydrogenase, ALDH2, play a large role in the metabolism of acetaldehyde. Thus, it is important to characterize how genetic variations can lead to different exposures and responses to ethanol and acetaldehyde. While the pharmacokinetics of ethanol metabolism through alcohol dehydrogenase have been thoroughly explored in previous studies, in this paper, we combined a base physiologically-based pharmacokinetic (PBPK) model with a whole-body genome-scale model (WBM) to gain further insight into the effect of other less explored processes and genetic variations on ethanol metabolism. This combined model was fit to clinical data and used to show the effect of alcohol concentrations, organ damage, ALDH2 enzyme polymorphisms, and ALDH2-inhibiting drug disulfiram on ethanol and acetaldehyde exposure. Through estimating the reaction rates of auxiliary processes with dynamic Flux Balance Analysis, The PBPK-WBM was able to navigate around a lack of kinetic constants traditionally associated with PK modelling and demonstrate the compensatory effects of the body in response to decreased liver enzyme expression. Additionally, the model demonstrated that acetaldehyde exposure increased with higher dosages of disulfiram and decreased ALDH2 efficiency, and that moderate consumption rates of ethanol could lead to unexpected accumulations in acetaldehyde. This modelling framework combines the comprehensive steady-state analyses from genome-scale models with the dynamics of traditional PK models to create a highly personalized form of PBPK modelling that can push the boundaries of precision medicine.
An auxin signaling network translates low-sugar-state input into compensated cell enlargement in the fugu5 cotyledon
Authors: Tabeta Hiromitsu , Watanabe Shunsuke , Fukuda Keita , Gunji Shizuka , Asaoka Mariko , Hirai Masami Yokota , Seo Mitsunori , Tsukaya Hirokazu , Ferjani Ali
Published: August 2021

In plants, the effective mobilization of seed nutrient reserves is crucial during germination and for seedling establishment. The Arabidopsis H+-PPase-loss-of-function fugu5 mutants exhibit a reduced number of cells in the cotyledons. This leads to enhanced post-mitotic cell expansion, also known as compensated cell enlargement (CCE). While decreased cell numbers have been ascribed to reduced gluconeogenesis from triacylglycerol, the molecular mechanisms underlying CCE remain ill-known. Given the role of indole 3-butyric acid (IBA) in cotyledon development, and because CCE in fugu5 is specifically and completely cancelled by ech2, which shows defective IBA-to-indoleacetic acid (IAA) conversion, IBA has emerged as a potential regulator of CCE. Here, to further illuminate the regulatory role of IBA in CCE, we used a series of high-order mutants that harbored a specific defect in IBA-to-IAA conversion, IBA efflux, IAA signaling, or vacuolar type H+-ATPase (V-ATPase) activity and analyzed the genetic interaction with fugu5–1. We found that while CCE in fugu5 was promoted by IBA, defects in IBA-to-IAA conversion, IAA response, or the V-ATPase activity alone cancelled CCE. Consistently, endogenous IAA in fugu5 reached a level 2.2-fold higher than the WT in 1-week-old seedlings. Finally, the above findings were validated in icl–2, mls–2, pck1–2 and ibr10 mutants, in which CCE was triggered by low sugar contents. This provides a scenario in which following seed germination, the low-sugar-state triggers IAA synthesis, leading to CCE through the activation of the V-ATPase. These findings illustrate how fine-tuning cell and organ size regulation depend on interplays between metabolism and IAA levels in plants.
Rubicon prevents autophagic degradation of GATA4 to promote Sertoli cell function
Authors: Yamamuro Tadashi , Nakamura Shuhei , Yamano Yu , Endo Tsutomu , Yanagawa Kyosuke , Tokumura Ayaka , Matsumura Takafumi , Kobayashi Kiyonori , Mori Hideto , Enokidani Yusuke , Yoshida Gota , Imoto Hitomi , Kawabata Tsuyoshi , Hamasaki Maho , Kuma Akiko , Kuribayashi Sohei , Takezawa Kentaro , Okada Yuki , Ozawa Manabu , Fukuhara Shinichiro , Shinohara Takashi , Ikawa Masahito , Yoshimori Tamotsu
Published: August 2021

Autophagy degrades unnecessary proteins or damaged organelles to maintain cellular function. Therefore, autophagy has a preventive role against various diseases including hepatic disorders, neurodegenerative diseases, and cancer. Although autophagy in germ cells or Sertoli cells is known to be required for spermatogenesis and male fertility, it remains poorly understood how autophagy participates in spermatogenesis. We found that systemic knockout mice of Rubicon, a negative regulator of autophagy, exhibited a substantial reduction in testicular weight, spermatogenesis, and male fertility, associated with upregulation of autophagy. Rubicon-null mice also had lower levels of mRNAs of Sertoli cell–related genes in testis. Importantly, Rubicon knockout in Sertoli cells, but not in germ cells, caused a defect in spermatogenesis and germline stem cell maintenance in mice, indicating a critical role of Rubicon in Sertoli cells. In mechanistic terms, genetic loss of Rubicon promoted autophagic degradation of GATA4, a transcription factor that is essential for Sertoli cell function. Furthermore, androgen antagonists caused a significant decrease in the levels of Rubicon and GATA4 in testis, accompanied by elevated autophagy. Collectively, we propose that Rubicon promotes Sertoli cell function by preventing autophagic degradation of GATA4, and that this mechanism could be regulated by androgens.
Forecasting of phenotypic and genetic outcomes of experimental evolution in Pseudomonas protegens
Authors: Pentz Jennifer T. , Lind Peter A.
Published: August 2021

Experimental evolution with microbes is often highly repeatable under identical conditions, suggesting the possibility to predict short-term evolution. However, it is not clear to what degree evolutionary forecasts can be extended to related species in non-identical environments, which would allow testing of general predictive models and fundamental biological assumptions. To develop an extended model system for evolutionary forecasting, we used previous data and models of the genotype-to-phenotype map from the wrinkly spreader system in Pseudomonas fluorescens SBW25 to make predictions of evolutionary outcomes on different biological levels for Pseudomonas protegens Pf-5. In addition to sequence divergence (78% amino acid and 81% nucleotide identity) for the genes targeted by mutations, these species also differ in the inability of Pf-5 to make cellulose, which is the main structural basis for the adaptive phenotype in SBW25. The experimental conditions were changed compared to the SBW25 system to test if forecasts were extendable to a non-identical environment. Forty-three mutants with increased ability to colonize the air-liquid interface were isolated, and the majority had reduced motility and was partly dependent on the Pel exopolysaccharide as a structural component. Most (38/43) mutations are expected to disrupt negative regulation of the same three diguanylate cyclases as in SBW25, with a smaller number of mutations in promoter regions, including an uncharacterized polysaccharide synthase operon. A mathematical model developed for SBW25 predicted the order of the three main pathways and the genes targeted by mutations, but differences in fitness between mutants and mutational biases also appear to influence outcomes. Mutated regions in proteins could be predicted in most cases (16/22), but parallelism at the nucleotide level was low and mutational hot spot sites were not conserved. This study demonstrates the potential of short-term evolutionary forecasting in experimental populations and provides testable predictions for evolutionary outcomes in other Pseudomonas species.
Recovery from heat shock requires the microRNA pathway in Caenorhabditis elegans
Authors: Pagliuso Delaney C. , Bodas Devavrat M. , Pasquinelli Amy E.
Published: August 2021

The heat shock response (HSR) is a highly conserved cellular process that promotes survival during stress. A hallmark of the HSR is the rapid induction of heat shock proteins (HSPs), such as HSP-70, by transcriptional activation. Once the stress is alleviated, HSPs return to near basal levels through incompletely understood mechanisms. Here, we show that the microRNA pathway acts during heat shock recovery inCaenorhabditis elegans. Depletion of the miRNA Argonaute, Argonaute Like Gene 1 (ALG-1), after an episode of heat shock resulted in decreased survival and perdurance of highhsp-70levels. We present evidence that regulation ofhsp-70is dependent on miR-85 and sequences in thehsp-703’UTR that contain target sites for this miRNA. Regulation ofhsp-70by the miRNA pathway was found to be particularly important during recovery from HS, as animals that lacked miR-85 or its target sites in thehsp-703’UTR overexpressed HSP-70 and exhibited reduced viability. In summary, our findings show that down-regulation ofhsp-70by miR-85 after HS promotes survival, highlighting a previously unappreciated role for the miRNA pathway during recovery from stress.