bluuebunny/crossref_metadata_2025 huggingface dataset:
Sigma Metric Evaluation of Drugs in a Clinical Laboratory: Importance of Choosing Appropriate Total Allowable Error and a Troubleshooting Roadmap
Authors: Sharma Lokesh Kumar , Datta Rashmi Rasi , Sharma Neera
Published: May 2021

Objectives Stringent quality control is an essential requisite of diagnostic laboratories to deliver consistent results. Measures used to assess the performance of a clinical chemistry laboratory are internal quality control and external quality assurance scheme (EQAS). However, the number of errors cannot be measured by the above but can be quantified by sigma metrics. The sigma scale varies from 0 to 6 with “6” being the ideal goal, which is calculated by using total allowable error (TEa), bias, and precision. However, there is no proper consensus for setting a TEa goal, and influence of this limiting factor during routine laboratory practice and sigma calculation has not been adequately determined. The study evaluates the impact of the choice of TEa value on sigma score derivation and also describes a detailed structured approach (followed by the study laboratory) to determine the potential causes of errors causing poor sigma score.

Materials and Methods The study was conducted at a clinical biochemistry laboratory of a central government tertiary care hospital. Internal and external quality control data were evaluated for a period of 5 months from October 2019 to February 2020. Three drugs (carbamazepine, phenytoin, and valproate) were evaluated on the sigma scale using two different TEa values to determine significant difference, if any.

Statistical Analysis Bias was calculated using the following formula: Bias% = (laboratory EQAS result − peer group mean) × 100 / peer group mean Peer group mean sigma metric was calculated using the standard equation: Sigma value = TEa − bias / coefficient of variation (CV)%.

Results Impressive sigma scores (> 3 sigma) for two out of three drugs were obtained with TEa value 25, while with TEa value 15, sigma score was distinctly dissimilar and warranted root cause analysis and corrective action plans to be implemented for both valproate and carbamazepine.

Conclusions The current study evidently recognizes that distinctly different sigma values can be obtained, depending on the TEa values selected, and using the same bias and precision values in the sigma equation. The laboratories should thereby choose appropriate TEa goals and make judicious use of sigma metric as a quality improvement tool.
The Pediatric Spine
Authors: Colafati Giovanna Stefania , Marrazzo Antonio , Cirillo Marco , d'Angelo Paola , Barbuti Domenico , Tanturri de Horatio Laura , Tomà Paolo , Bartoloni Alessandra
Published: May 2021

The spine, a frequently investigated site in children, has a complex development in relation to both nervous and bone/cartilaginous structures and shows several particular features in children compared with adults. We report the main normal variants and pathologies of the pediatric spine, from the prenatal period to adolescence, focusing on a multimodality imaging approach.
Calcium Channels Genes and Their Epilepsy Phenotypes
Authors: Pulvirenti Giulio , Caccamo Martina , Lo Bianco Manuela , Mazzurco Marina , Praticò Elena R. , Giallongo Alessandro , Gangi Gloria , Zanghì Antonio , Falsaperla Raffaele
Published: May 2021

Calcium (Ca2+) channel gene mutations play an important role in the pathogenesis of neurological episodic disorders like epilepsy. CACNA1A and CACNA1H genes are involved in the synthesis of calcium channels. Mutations in the α1A subunit of the P/Q type voltage-gated calcium channel gene (CACNA1A) located in 19p13.13, which encodes for the transmembrane pore-forming subunit of CAV2.1 voltage-dependent calcium channel, have been correlated to a large clinical spectrum of epilepsy such as idiopathic genetic epilepsy, early infantile epilepsy, and febrile seizures. Moreover, CACNA1A mutations have been demonstrated to be involved in spinocerebellar ataxia type 6, familiar hemiplegic migraine, episodic ataxia type 2, early-onset encephalopathy, and hemiconvulsion–hemiplegia epilepsy syndrome. This wide phenotype heterogeneity associated with CACNA1A mutations is correlated to different clinical and electrophysiological manifestations. CACNA1H gene, located in 16p13.3, encodes the α1H subunit of T-type calcium channel, expressing the transmembrane pore-forming subunit Cav3.2. Despite data still remain controversial, it has been identified as an important gene whose mutations seem strictly related to the pathogenesis of childhood absence epilepsy and other generalized epilepsies. The studied variants are mainly gain-of-function, hence responsible for an increase in neuronal susceptibility to seizures. CACNA1H mutations have also been associated with autism spectrum disorder and other behavior disorders. More recently, also amyotrophic lateral sclerosis has been related to CACNA1H alterations. The aim of this review, other than describe the CACNA1A and CACNA1H gene functions, is to identify mutations reported in literature and to analyze their possible correlations with specific epileptic disorders, purposing to guide an appropriate medical treatment recommendation.
Phosphor-free InGaN nanopillar white LEDs by random clustering of mono-sized nanospheres
Authors: Fu Wai Yuen , Choi Hoi Wai
Published: May 2021

Nanosphere lithography with mono-sized nanospheres has been employed as a patterning tool of nanostructuring to achieve phosphor-free white-light emission in this study. Nanostructuring of InGaN/GaN quantum wells induces spectral blue shift due to strain relaxation, the extent of which depends on the sizes of the nanopillars. Nano-clusters of various sizes are formed as a result of random clustering of the mono-sized nanospheres, so that the clusters emit at different wavelengths as they are strain-relaxed to different levels. A Monte Carlo simulation has been employed to simulate the clustering patterns, while molecular dynamics and k·p Schrödinger calculations have been carried out to identify the appropriate nano-cluster distribution for phosphor-free white-light emission. The fabricated device achieves a color rendering index (CRI) of about 76 with an overall luminous efficacy of 2.6 lm/W under DC operation and 11.0 lm/W under pulsed operation.
Coherent phonon-mediated dynamics for an addressable transducer of coupled micro-mechanical resonators
Authors: Gong Zhi-Cheng , Fu Hao , Mao Tian-Hua , Yuan Quan , Shen Cheng-Yu , Sun Chang-Pu , Li Yong , Cao Geng-Yu
Published: May 2021

We present coherent phonon-mediated dynamics for addressable motion transfer in a scalable mechanical transducer consisting of three nearest-neighboring coupled micro-cantilevers. To connect two distant cantilevers without direct interaction, two parametric pumps are applied to couple the cantilevers to an intermediate mechanical mode simultaneously. We demonstrate that the distant cantilevers can be coherently coupled even when the intermediate mode is effectively decoupled as a result of two-pump on-resonance coupling. The phonon-mediated coupling is controlled for long-range transferring of both iterating and intra-mode motions while avoid unwanted exciting of the intermediate mode.
Impurity effects on trapped electron modes in tokamak plasmas with inverted electron density profile
Authors: Zhang X. R. , Dong J. Q. , Du H. R. , Liu J. Y. , Shen Y. , Li J. , Han M. K. , Wang F. , Dai S. Y. , Sang C. F. , Wang Z. X.
Published: May 2021

Impurity effects on trapped electron modes (TEMs) in tokamak plasmas with inverted electron density profile (IEDP) are numerically investigated with a gyrokinetic integral eigenmode equation. It is found that different from the negative gradient of normal electron density profile, the positive gradient of the IEDP has a stabilizing effect on TEM in the presence of impurity ions. The electron temperature gradient threshold for TEM excitation increases not only with the increasing absolute value of IEDP but also with increasing impurity content. Furthermore, the effects of different impurity species and different impurity peaking profiles on TEMs with the IEDP are analyzed in detail. It is shown that there is a transition point of impurity density profile, on both sides of which the impurity has opposite effects on TEM. The dependence of such a transition point on electron temperature and density gradients is obtained numerically. Besides, the synergistic effects of ion temperature gradient and impurity density gradient are studied, in which a similar transition point of the ion temperature gradient is also identified in the case of outwardly peaked impurity density profile. In addition, impurity effects on the characteristics of mode structure and on the radial transport coefficients in positive and negative magnetic shear regions are discussed as well based on quasi-linear mixing length estimation.
Strong interlayer charge transfer due to exciton condensation in an electrically isolated GaAs quantum well bilayer
Authors: Jang Joonho , Yoo Heun Mo , Pfeiffer L. N. , West K. W. , Baldwin K. W. , Ashoori Raymond C.
Published: May 2021

We introduce a design of electrically isolated “floating” bilayer GaAs quantum wells (QW), in which application of a large gating voltage controllably and highly reproducibly induces charges that remain trapped in the bilayer after removal of the gating voltage. At smaller gate voltages, the bilayer is fully electrically isolated from external electrodes by thick insulating barriers. This design permits full control of the total and differential densities of two coupled 2D electron systems. The floating bilayer design provides a unique approach for studying systems inaccessible by simple transport measurements. It also provides the ability to measure the charge transfer between the layers, even when the in-plane resistivities of the 2D systems diverge. We measure the capacitance and inter-layer tunneling spectra of the QW bilayer with independent control of the top and bottom layer electron densities. Our measurements display strongly enhanced inter-layer tunneling current at vT=1, a signature of exciton condensation of a strongly interlayer-correlated bilayer system. With fully tunable densities of individual layers, the floating bilayer QW system provides a versatile platform to access previously unavailable information on the quantum phases in electron bilayer systems.
Molecular diffusion analysis of dynamic blood flow and plasma separation driven by self-powered microfluidic devices
Authors: Woo Sung Oh , Oh Myungkeun , Nietfeld Kyle , Boehler Bailey , Choi Yongki
Published: May 2021

Integration of microfluidic devices with pressure-driven, self-powered fluid flow propulsion methods has provided a very effective solution for on-chip, droplet blood testing applications. However, precise understanding of the physical process governing fluid dynamics in polydimethylsiloxane (PDMS)-based microfluidic devices remains unclear. Here, we propose a pressure-driven diffusion model using Fick's law and the ideal gas law, the results of which agree well with the experimental fluid dynamics observed in our vacuum pocket-assisted, self-powered microfluidic devices. Notably, this model enables us to precisely tune the flow rate by adjusting two geometrical parameters of the vacuum pocket. By linking the self-powered fluid flow propulsion method to the sedimentation, we also show that direct plasma separation from a drop of whole blood can be achieved using only a simple construction without the need for external power sources, connectors, or a complex operational procedure. Finally, the potential of the vacuum pocket, along with a removable vacuum battery to be integrated with non-PDMS microfluidic devices to drive and control the fluid flow, is demonstrated.
Two-dimensional vibrational–electronic spectra with semiclassical mechanics
Authors: Polley Kritanjan , Loring Roger F.
Published: May 2021

Two-dimensional vibrational–electronic (2DVE) spectra probe the effects on vibronic spectra of initial vibrational excitation in an electronic ground state. The optimized mean trajectory (OMT) approximation is a semiclassical method for computing nonlinear spectra from response functions. Ensembles of classical trajectories are subject to semiclassical quantization conditions, with the radiation–matter interaction inducing discontinuous transitions. This approach has been previously applied to two-dimensional infrared and electronic spectra and is extended here to 2DVE spectra. For a system including excitonic coupling, vibronic coupling, and interaction of a chromophore vibration with a resonant environment, the OMT method is shown to well approximate exact quantum dynamics.
Numerical investigation of single- and two-phase flow in porous media with a bifurcated fracture
Authors: Zhu Zhengwen , Liu Jianjun , Liu Hejuan , Wu Mingyang , Song Zhenlong
Published: May 2021

Considering that fractures arising from fracturing systems have bifurcation characteristics, mathematical models for single- and two-phase flow in porous media with a bifurcated fracture (BFPM) were established. The phase-field method was adopted to trace the oil–water interface, and the influence of fracture morphology, boundary conditions, gravity, and wettability on imbibition in BFPM was discussed. The results are as follows: (1) during single-phase flow in BFPM, the velocity in the bifurcated fracture was several orders of magnitude greater than that in the matrix. (2) Imbibition in BFPM includes countercurrent imbibition and the combination of co-current and countercurrent imbibition. The bifurcated fracture produces an increase in matrix pores that participate in imbibition, thus increasing the oil recovery factor by approximately 30% during simulation. (3) Closing an outlet of the bifurcated fracture has minimal effect on imbibition during the early stage (approximately the first 6 s) and an inhibitory effect during the middle and late stages (after 6 s), which leads to a decrease in oil recovery factor. (4) When the surface tension value is low (0.1 and 1 mN/m), disregarding the effect of gravity during imbibition results in an overestimated oil recovery factor value, while a large surface tension value (20 and 25 mN/m) produces the opposite effect. (5) Similar to the laws followed in porous media with pure pores and a single fracture, improving BFPM wettability increases the oil recovery factor value. This study can provide guidance for the production of low-permeability reservoirs.
Making quantitative biomicrofluidics from microbore tubing and 3D-printed adapters
Authors: Kabandana Giraso Keza Monia , Ratajczak Adam Michael , Chen Chengpeng
Published: May 2021

Microfluidic technology has tremendously facilitated the development of in vitro cell cultures and studies. Conventionally, microfluidic devices are fabricated with extensive facilities by well-trained researchers, which hinder the widespread adoption of the technology for broader applications. Enlightened by the fact that low-cost microbore tubing is a natural microfluidic channel, we developed a series of adaptors in a toolkit that can twine, connect, organize, and configure the tubing to produce functional microfluidic units. Three subsets of the toolkit were thoroughly developed: the tubing and scoring tools, the flow adaptors, and the 3D cell culture suite. To demonstrate the usefulness and versatility of the toolkit, we assembled a microfluidic device and successfully applied it for 3D macrophage cultures, flow-based stimulation, and automated near real-time quantitation with new knowledge generated. Overall, we present a new technology that allows simple, fast, and robust assembly of customizable and scalable microfluidic devices with minimal facilities, which is broadly applicable to research that needs or could be enhanced by microfluidics.
Optical Communication
Authors: Elliott Barry
Published: May 2021

Optical Communication is a foundational reference covering the principles and applications of optics. The book offers a broad understanding of optics basics, the physics and mathematics behind the transmission of light, the devices that affect the passage of light, and the practical applications of optical theory in communications. It covers theoretical and practical applications of optical technology. The book demonstrates how the physics of optics translates into applications in telecommunications, optical communications in free space, and other media.

This book:Offers a practical guide to optics and its applications in communications complementing existing works on its theory.Addresses the work of international standards bodies such as the ITU and ISO in aligning the physics behind the subject and the availability of standard products that can implement modern high-speed communications networks.Provides introductory concepts for those new to the field as well as students and professionals.

This book is suitable for physicists, engineers, technicians, and chemists. Undergraduate students or anyone in the optical field who may need a grounding in associated applications or an early introduction to the field will find this book a valuable reference.
The Transmission of Light and the Electromagnetic Spectrum
Authors: Elliott Barry
Published: May 2021

Light, like all its counterparts across the electromagnetic spectrum, has a wave-particle duality, that is, it has the properties of a wave and a particle, and the particles we call photons. It suits us when we are considering the subject of communications to usually think of light as a wave, which leads to an easier understanding of the properties of reflection, refraction and polarization. Considering light in its particle form has more benefit when we look at the subject of producing light in LEDs and lasers. In this chapter we looks at the basics of light transmission including the units and parameters of measurement and the upper speed limit of light. We shall also try to define the upper and lower limits of the electromagnetic spectrum and focus on the radio and optical ‘windows’ that allow for communications. In particular we look at the spectral response of four media, air, water, plastic and glass and identify the ‘bands’ of lowest attenuation, in the infra-red and visible light spectrum, that allow for successful communications links.
Encoding Information onto Light
Authors: Elliott Barry
Published: May 2021

To make use of optical fibre communications channels we must encode useful information onto an optical carrier and successfully decode it at the receiving end. This can be done in either an analog or digital format although digital codes now represent the vast majority of applications. The advantages of digitizing a signal are principally that it becomes infinitely reproducible without errors and becomes subject to easy storage and manipulation. In this chapter we consider the parameters that we can vary to encode information onto a light wave such as amplitude, wavelength, phase and polarization. There are many different ways of modulating a signal but we shall focus on the three types most often seen in optical links and they are Non Return to Zero, NRZ, Pulse Amplitude Modulation, PAM, and Quadrature Amplitude Modulation. QAM. Using complex codes to squeeze more data into a limited bandwidth is always going to be limited by noise. Ethernet dominates local area networks, LANs, and now overlaps significantly with the traditional world of telecommunications. The principal optical interfaces used with Ethernet are reviewed and summarised and in particular where the latest high speed links are moving to more sophisticated protocols such as PAM and QAM.
The components of optical communications
Authors: Elliott Barry
Published: May 2021

We have encountered many of the components of optical communications in earlier chapters. In Chapter 3 we encountered Faraday isolators; in Chapter 4 diffraction gratings which are used in wavelength division multiplexing devices, in Chapter 5 GRIN and Fresnel lenses plus splitters and couplers. In Chapter 6 we looked at the active components of LEDs and lasers and in Chapter 8 we looked at optical fibres. In this chapter we will consider some of the other optical components that are essential to a practical and working optical communication system. There are optical connectors and splices, patch panels and cables and an essential device called an Erbium Doped Fibre Amplifier, or EDFA for short. EDFAs, isolators/circulators, Bragg gratings and MEMs, Micro-Electro Mechanical Systems, all contribute to the essential requirement of wavelength division multiplexing, but without the accompanying array of connectors, splices and cables the optical communication system would not be complete or usable.
Inoculum effect of antimicrobial peptides
Authors: Loffredo Maria Rosa , Savini Filippo , Bobone Sara , Casciaro Bruno , Franzyk Henrik , Mangoni Maria Luisa , Stella Lorenzo
Published: May 2021

Significance

Bacterial drug resistance is a crucial threat to global health, and antimicrobials with novel mechanisms of action are urgently needed. Antimicrobial peptides are natural molecules that kill bacteria mostly by perturbing their membranes, and they constitute promising compounds for fighting resistant microbes. Their activity is normally tested under standardized conditions of bacterial density. However, the bacterial load in clinically relevant infections varies by many orders of magnitude. Here, we show that the minimum peptide concentration needed for bacterial growth inhibition can vary by more than 100-fold with an increase in the density of cells in the initial inoculum of the assay (a phenomenon termed the “inoculum effect”). These findings question the utility of the currently used activity screening assays.
Structure of Ycf1p reveals the transmembrane domain TMD0 and the regulatory region of ABCC transporters
Authors: Bickers Sarah C. , Benlekbir Samir , Rubinstein John L. , Kanelis Voula
Published: May 2021

Significance

The Ycf1p structure provides an atomic model for the TMD0 domain of ABCC transporters and for two segments of the regulatory (R) region that links NBD1 to TMD2. The orientation of TMD0 in Ycf1p differs from that seen in SUR1, the regulatory ABCC protein in K
ATP
channels, demonstrating flexibility in TMD0/ABC core contacts. The structure suggests how posttranslational modifications of the R region modulate ABC protein activity and provides a mechanistic understanding of several diseases that occur due to mutation of human homologs of Ycf1p.
Flexoelectricity in soft elastomers and the molecular mechanisms underpinning the design and emergence of giant flexoelectricity
Authors: Grasinger Matthew , Mozaffari Kosar , Sharma Pradeep
Published: May 2021

Significance

The molecular-scale phenomena that lead to the emergence of the flexoelectric effect in elastomers are not well understood. We present a molecular-to-continuum scale theory and show it to be valid for common types of elastomers. We unravel a mechanism for achieving giant flexoelectricity—which finds support in prior experimental results. The multiscale theory is then leveraged for material design and we propose specific modalities for 1) the emergence of piezoelectricity, 2) tuning the direction of flexoelectricity, and 3) flexoelectricity which is invariant with respect to spurious deformations. These developments may pave the way for the future development of efficient soft energy harvesters, sensors, and actuators, and may prove useful for high-degree-of-freedom soft robots and artificial muscles.
Triphasia trifolia (limeberry).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro
Published: May 2021

T. trifolia is an aggressive invasive plant with the capacity to grow in sunny open areas as well as in shaded areas beneath the canopy forest (Daley et al., 2012). It is a woody shrub classified as a "weed" and included in the Global Compendium of Weeds (Randall, 2012). T. trifolia spreads by seeds that can be easily dispersed by animals, mainly by birds, facilitating the invasion of this species into native forests. Seeds have high germination rates under natural conditions and grow forming dense-spiny thickets in the understory of the forest (Clark, 2003; Daley et al., 2012). For example, vegetation surveys performed in the understory of secondary forests on the islands of St. Croix (US Virgin Islands) have showed stem counts for this species exceeding 38,000 stems per hectare (Clark, 2003).
Imperata cylindrica (cogon grass).
Authors: Parker Chris
Published: May 2021

I. cylindrica is a serious weed not only in crops but also in natural areas, causing serious economic and environmental damage. The ability of I. cylindrica to effectively compete for water and nutrients, spread and persist through the production of seeds and rhizomes that can survive a wide range of environmental conditions, and its allelopathic effects and pyrogenic nature, allow it to exclude native plant species and other desirable plants and dominate large areas of land.
Melinis minutiflora (molasses grass).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro
Published: May 2021

M. minutiflora is a grass which is used widely as a fodder species for livestock and for its ability to grow well on poor soils, but which is also strongly invasive. It has been introduced intentionally around the world, and also probably accidentally as a seed contaminant. It is difficult to eradicate when present, and poses a threat to agriculture and the environment. This species is highly invasive and grows forming dense mats that exclude native species, alter successional processes, reduce native tree and grass regeneration, and increase intensity and frequency of fires (Hoffmann et al., 2004).
Xanthomonas campestris pv. campestris (black rot).
Authors: Mortensen Carmen Nieves
Published: May 2021

Black rot is considered the most important worldwide disease of crucifers. The disease is known to exist in the cool coastal climates of northern Europe and North America but was seldom a problem there until the 1990s. Its potential for crop damage is also considered low in New Zealand, and parts of Australia. In many regions of Central and Eastern Europe, Central Asia (Kazakhstan), China, tropical and subtropical regions of Asia, Africa and South America where brassicas are common and cultivated without crop rotation, black rot is always present. Seed production in those regions is commonly associated with high levels of seedborne Xcc (Williams, 1980). Even minor, visually undetectable development of black rot may considerably increase damage to plants by soft rot caused by Erwinia carotovora, Pseudomonas spp. and other opportunistic pathogens (Djalilov et al., 1989).
Heterodera ustinovi (grass cyst nematode).
Authors: Powers Thomas
Published: May 2021

There is limited evidence available to suggest that H. ustinovi is invasive. The identical COI halpotypes shared between the USA and Europe most likely represent recent introductions. The small amount of genetic information from North America suggests that H. ustinovi is widespread in the south west (Arizona), midwest (Ohio) and New England states, with little genetic differentiation. H. ustinovi has not been found on any plant species in the USA other than introduced Agrostis species and in turf/golf course settings. A lot of nematodes are transported in turf from turf farms. The initial discovery on native Agrostis in the Ukraine would suggest a potential native parasite existing on a native plant species, but, there are very few of samples on which to base these comparisons.
Statistical mechanics of Floquet quantum matter: exact and emergent conservation laws
Authors: Haldar Asmi , Das Arnab
Published: May 2021

Equilibrium statistical mechanics rests on the assumption of chaotic dynamics of a system modulo the conservation laws of local observables: extremization of entropy immediately gives Gibbs’ ensemble (GE) for energy conserving systems and a generalized version of it (GGE) when the number of local conserved quantities is more than one. Through the last decade, statistical mechanics has been extended to describe the late-time behaviour of periodically driven (Floquet) quantum matter starting from a generic state. The structure built on the fundamental assumptions of ergodicity and identification of the relevant conservation laws in this inherently non-equilibrium setting. More recently, it has been shown that the statistical mechanics of Floquet systems has a much richer structure due to the existence of emergent conservation laws: these are approximate but stable conservation laws arising due to the drive, and are not present in the undriven system. Extensive numerical and analytical results support perpetual stability of these emergent (though approximate) conservation laws, probably even in the thermodynamic limit. This banks on the recent finding of a sharp threshold for Floquet thermalization in clean, interacting non-integrable Floquet systems. This indicates to the possibility of stable Floquet phases of matter in disorder-free systems. This review intends to give a self-contained theoretical overview of these developments for a broad physics audience. We conclude by briefly surveying the current experimental scenario.
Controlling adhesion using AC electric fields across fluid films
Authors: Perez-Martinez Carla S , Groves Timothy S , Perkin Susan
Published: May 2021

We demonstrate reversible and switchable actuation using AC electric fields to bring two surfaces separated by a thin film of ionic fluid in and out of adhesive contact. Using a surface force balance we apply electric fields normal to a crossed-cylinder contact and measure directly the adhesive force and surface separation with sub-molecular resolution. Taking advantage of the oscillatory structural force acting between the surfaces across the fluid, which we show to be unaffected by the AC field, we pick between the distinct (quantized) adhesive states through precise tuning of the field. This proof-of-concept indicates exquisite control of surface interactions using an external field.
Buckling without bending morphogenesis: nonlinearities, spatial confinement, and branching hierarchies
Authors: Gandikota M C , Schwarz J M
Published: May 2021

During morphogenesis, a featureless convex cerebellum develops folds. As it does so, the cortex thickness is thinnest at the crest (gyri) and thickest at the trough (sulci) of the folds. This observation cannot be simply explained by elastic theories of buckling. A recent minimal model explained this phenomenon by modeling the developing cortex as a growing fluid under the constraints of radially spanning elastic fibers, a plia membrane and a nongrowing sub-cortex (Engstrom et al 2019 Phys. Rev. X 8 041053). In this minimal buckling without bending morphogenesis (BWBM) model, the elastic fibers were assumed to act linearly with strain. Here, we explore how nonlinear elasticity influences shape development within BWBM. The nonlinear elasticity generates a quadratic nonlinearity in the differential equation governing the system’s shape and leads to sharper troughs and wider crests, which is an identifying characteristic of cerebellar folds at later stages in development. As developing organs are typically not in isolation, we also explore the effects of steric confinement, and observe flattening of the crests. Finally, as a paradigmatic example, we propose a hierarchical version of BWBM from which a novel mechanism of branching morphogenesis naturally emerges to qualitatively predict later stages of the morphology of the developing cerebellum.
Nonlinear electric conductivity and THz-induced charge transport in graphene
Authors: Sato Shunsuke A , Rubio Angel
Published: May 2021

Based on the quantum master equation approach, the nonlinear electric conductivity of graphene is investigated under static electric fields for various chemical potential shifts. The simulation results show that, as the field strength increases, the effective conductivity is firstly suppressed, reflecting the depletion of effective carriers due to the large displacement in the Brillouin zone caused by the strong field. Then, as the field strength exceeds 1 MV m−1, the effective conductivity increases, overcoming the carrier depletion via the Landau–Zener tunneling process. Based on the nonlinear behavior of the conductivity, the charge transport induced by few-cycle THz pulses is studied to elucidate the ultrafast control of electric current in matter.
Structural, surface morphology and radiation shielding properties of barium ferrite powder
Authors: Ali Atif Mossad , Issa Shams A M , Algarni H , Tekin H O , Zakaly Hesham M H , Sayed M A , Rashad M
Published: May 2021

In this study, Barium ferrite (BaFe12O19) was prepared in powder form using the sol-gel method. Next, structural, surface morphology, and radiation shielding properties of Barium ferrite compound were determined using experimental and simulation methods. The structural and surface morphology were characterised using x-ray diffraction (XRD) and the scanning electron microscope (SEM). The formation of hexagonal structure has been verified by XRD patterns for synthesised pure BaFe12O19. The amplitude of XRD peaks declines as the FWHM rises, indicating that crystallinity has degraded and crystallite size has decreased. SEM images provide accurate representations of surfaces. The topography of the surface is characterized by the presence of several spherical granules. Additionally, the mean diameter of the spherical granules was determined to be approximately 30 nm using the histogram. Moreover, FLUKA simulation code was used to calculate some radiation shielding parameters such as linear attenuation coefficients (4.639, 0.554, 0.336 and 0.2013 cm−1), mass attenuation coefficients (0.8787, 0.1049, 0.0686 and 0.0381 cm2 g−1), half value layers (0.1494, 1.2512, 2.0629 and 3.4434 cm) and mean free path values (0.21554, 1.8051, 2.9762and 4.9677 cm) against 0.81, 0.356, 0.911 and 2.614 MeV photon energies, respectively. The results showed that synthesized Barium ferrite has good surface renditions and distinguished spherical granules along with promising gamma-ray attenuation properties.
Universal time delay in static spherically symmetric spacetimes for null and timelike signals *
Authors: Liu Haotian , Jia Junji
Published: May 2021

A perturbative method of computing the total travel time of both null and lightlike rays in arbitrary static spherically symmetric spacetimes in the weak field limit is proposed. The resultant total time takes a quasi-series form of the impact parameter. The coefficient of this series at a certain order n is shown to be determined by the asymptotic expansion of the metric functions to the order

. For the leading order(s), the time delay, as well as the difference between the time delays of two types of relativistic signals, is shown to take a universal form for all SSS spacetimes. This universal form depends on the mass M and a post-Newtonian parameter

of the spacetime. The analytical result is numerically verified using the central black hole of galaxy M87 as the gravitational lensing center.
Impact of lepton p

T
threshold on charge asymmetry predictions for inclusive W boson production in pp collisions at 13 TeV
Authors: Ocalan Kadir
Published: May 2021

This paper presents the impact of the lepton transverse momentum

threshold on the

boson charge asymmetry predictions in perturbative QCD for the inclusive

production in proton-proton (

) collisions. The predictions are obtained at various low-

thresholds

20, 25, 30, and 40 GeV in a fiducial region encompassing both the central and forward detector acceptances in terms of the lepton pseudorapidity

. The predicted distributions for the lepton charge asymmetry, which is defined by

(

), at the next-to-next-to-leading order (NNLO) accuracy are compared with the CMS and LHCb data at 8 TeV center-of-mass collision energy. The 8 TeV predictions reproduce the data fairly well within the quoted uncertainties. The predictions from the CT14 parton distribution function (PDF) model are in a slightly better agreement with the data over the other PDF sets that are tested. The 13 TeV predictions using various

thresholds are reported for

and the charge asymmetries that are defined in terms of the differential cross sections in bins of the

boson rapidity

(

) and transverse momentum

(

). The NNLO predictions for the

,

, and

distributions are assessed to be in close correlation with the

value. The

and

distributions are particularly shown to be more correlated at a higher

threshold. The

distributions are also reported from the merged predictions with improved accuracy by the inclusion of the next-to-next-to-next-to-leading logarithm (N3LL) corrections, i.e., at NNLO+N3LL. The predicted distributions from various

thresholds represent a finer probe in terms of the capability to provide more constraints on the ratio of

and

quark distribution functions in the parton momentum fraction range

.
Costs of avoiding net negative emissions under a carbon budget
Authors: van der Wijst Kaj-Ivar , Hof Andries F , van Vuuren Detlef P
Published: May 2021

The 2 °C and 1.5 °C temperature targets of the Paris Agreement can be interpreted as targets never to be exceeded, or as end-of-century targets. Recent literature proposes to move away from the latter, in favour of avoiding a temperature overshoot and the associated net negative emissions. To inform this discussion, we investigate under which conditions avoiding an overshoot is economically attractive. We show that some form of overshoot is attractive under a wide range of assumptions, even when considering the extra damages due to additional climate change in the optimisation process. For medium assumptions regarding mitigation costs and climate damages, avoiding net negative emissions leads to an increase in total costs until 2100 of 5% to 14%. However, avoiding overshoot only leads to some additional costs when mitigation costs are low, damages are high and when using a low discount rate. Finally, if damages are not fully reversible, avoiding net negative emissions can even become attractive. Under these conditions, avoiding overshoot may be justified, especially when non-monetary risks are considered.
Contrasting the role of human- and lightning-caused wildfires on future fire regimes on a Central Oregon landscape
Authors: Barros Ana M G , Day Michelle A , Preisler Haiganoush K , Abatzoglou John T , Krawchuk Meg A , Houtman Rachel , Ager Alan A
Published: May 2021

Climate change is expected to increase fire activity in many regions of the globe, but the relative role of human vs. lightning-caused ignitions on future fire regimes is unclear. We developed statistical models that account for the spatiotemporal ignition patterns by cause in the eastern slopes of the Cascades in Oregon, USA. Projected changes in energy release component from a suite of climate models were used with our model to quantify changes in frequency and extent of human and lightning-caused fires and record-breaking events based on sizes of individual fires between contemporary (2006 −2015) and mid-century conditions (2031–2060). No significant change was projected for the number of human-caused fire ignitions, but we projected a 14% reduction in lightning-caused ignitions under future conditions. Mean fire sizes were 31% and 22% larger under future conditions (2031–2060) for human and lightning-caused ignitions, respectively. All but one climate model projected increased frequency of record-breaking events relative to the contemporary period, with the largest future fires being about twice the size of those of the contemporary period. This work contributes to understanding the role of lightning- and human-caused fires on future fire regimes and can help inform successful adaptation strategies in this landscape.
Long-term trends of satellite-based fine-mode aerosol optical depth over the Seto Inland Sea, Japan, over two decades (2001–2020)
Authors: Itahashi Syuichi , Sakurai Tatsuya , Shimadera Hikari , Araki Shin , Hayami Hiroshi
Published: May 2021

Air pollution over the Seto Inland Sea (SIS) is among the most severe of any region in Japan and is considered to be affected by both long-range and local pollution. To unravel the long-term trends of aerosol pollution over this region, in this study, measurements from the moderate resolution imaging spectroradiometer instrument onboard the Terra satellite were analyzed over two decades, from 2001 to 2020. Fine-mode aerosol optical depth (AODf) was calculated to estimate the amount of aerosol produced by anthropogenic emissions. The results showed that the AODf over the SIS increased from 2001 to 2004, had a flat trend from 2005 to 2009, and decreased from 2010 to 2020. To clarify the impact of long-range transport from the Asian continent to the SIS, the AODf over the Yellow Sea was also investigated and was found to increase and level off during the 2000s, after which it decreased, especially after 2014. This decrease can be attributed to emission regulations in China. The above analysis suggests that the aerosol pollution status in the SIS during the late 2010s was similar to that during the early 2000s. Over the SIS, the lowest AODf value was found in 2020, with the values in January–March and June–July approximately 30% and 30%–60% lower than the average values during the same periods in 2018–2019, respectively. The reduction found in January–March could be related to the decline in the long-range transport with restrictions on human activity due to the COVID-19 pandemic. Meanwhile, the reduction during June–July could be related to the decline of local emission sources. Considering the large SO2 decline in 2020, regulations on SO2 emitted from ships that started from 1 January 2020 are one possible factor for the improvement of aerosol pollution over the SIS in 2020.
Mapping the maximum extents of urban green spaces in 1039 cities using dense satellite images
Authors: Huang Conghong , Yang Jun , Clinton Nicholas , Yu Le , Huang Huabing , Dronova Iryna , Jin Jing
Published: May 2021

Spatial data of urban green spaces (UGS) are critical for cities worldwide to evaluate their progress towards achieving the urban sustainable development goals on UGS. However, UGS maps at the global scale with acceptable accuracies are not readily available. In this study, we mapped UGS of all 1039 mid- and large-sized cities across the globe in 2015 with dense remote sensing data (i.e. 51 494 Landsat images) and Google Earth Engine (GEE) platform. Also, we quantified the spatial distribution and accessibility of UGS within the cities. By combining the greenest pixel compositing method and the percentile-based image compositing method, we were able to obtain the maximum extent of UGS in cities while better differentiating UGS from other vegetation such as croplands. The mean overall classification accuracy reached 89.26% (SD = 3.26%), which was higher than existing global land cover products. Our maps showed that the mean UGS coverage in 1039 cities was 38.46% (SD = 20.27%), while the mean UGS accessibility was 82.67% (SD = 22.89%). However, there was a distinctive spatial equity issue as cities in high-income countries had higher coverage and better accessibility than cities in low-income countries. Besides developing a protocol for large-scale UGS mapping, our study results provide key baseline information to support international endeavors to fulfill the relevant urban sustainable development goals.
Effectiveness and impact studies of mangrove rehabilitation in the northern coast of West Java: A case study in Karawang Regency
Authors: Amin M A Al , Mulyana D , Damar A , Budiman M A K , Kamsari
Published: May 2021

Plenty of mangrove rehabilitation programs have been implemented on the northern coast of Java, including in Karawang Regency, both by the community and private companies’ participation through Corporate Social Responsibility (CSR). Over ten years, millions of mangrove plants have been planted. However, the results and impacts on the ecology and socio-economy have not been widely evaluated. An assessment and evaluation of the mangrove rehabilitation were carried out to determine the mangrove rehabilitation program’s results and effectiveness. This paper aims to determine rehabilitation’s condition and its impact on ecology and socio-economic surrounding the rehabilitation area. Mangrove rehabilitation activities at the northern coast of Karawang Regency have been provided new evidence that planting mangroves for rehabilitation purposes can not be seen as tree planting activities only. However, the impact and multiplier effects of its extraordinary benefits have not been paid much attention. Rehabilitation results have provided significant results, seen from the increase in the mangrove area, ecosystem quality, and positive impacts on ecology and significant socio-economic impacts indirect impacts, secondary impacts or cumulative impacts. It is necessary to develop and utilize rehabilitation results through a good socio-economic and institutional development approach to impact the community positively.
Study on zooplankton diversity aquatic ecobiology of Batang Toru River, North Sumatera, Indonesia
Authors: Asriansyah A , Wildan D M , Pratiwi N T M , Simanjuntak C P H , Sulistiono  , Hestirianoto T , Shafrudin D , Nugroho T
Published: May 2021

The Batang Toru River is a fairly long river, flowing from the North Tapanuli region and emptying into the Indian Ocean (South Tapanuli Regency). Increased deforestation in the Batang Toru River area has increased the potential for decreasing water quality of the Batang Toru River. The purpose of this study was to determine the condition of the water quality of the Batang Toru River. This research was conducted for 3 months (April, July, October), in the Batang Toru River and its surroundings (14 observation stations scattered from the area near the upstream to the coast). The data analysis used in this research is the analysis of the abundance and composition of the types of phytoplankton, the Diversity Index (H’), the Evennes Index (E), and the Dominance Index (C). Based on the research results, zooplankton in these waters consist of Six Phylum of zooplankton, such as Ciliophora (4 genera), Amoebozoa (2 genera), Cercozoa (1 genera), Rotifera (9 genera), Arthopoda (3 genera), and Annelida (2 genera). Diversity, Evenness, and Dominance Indices were around 0.349-1.847, 0.503-0.994 and 0.240-0.802. Based on the index value, it can be concluded that the Batang Toru River is classified as experiencing moderate ecological pressure.
Review: DNA metabarcoding approach for fisheries management
Authors: Ayu I P , Wardiatno Y , Butet N A , Madduppa H
Published: May 2021

Increased publications on meta-barcoding promote interests in studies associated with fisheries biodiversity, diet, and biomonitoring. These studies primarily concentrated on an ecosystem that has implications for fisheries management with complex interpretation. Various theories have arisen to describe the interactions among aquatic species and eventually contribute to the roles they play in ecology. Identifying organisms is also a prerequisite for answering questions in the field of ecology, which shows that reliable and accurate knowledge is important and desirable. Therefore, as a modern molecular technique, metabarcoding provides a realistic approach that lets ecologists analyze organisms in complex environmental samples and rapidly solve the problem associated with the food web in the coral reef ecosystem. This research explores the use of metabarcoding in fisheries management research and highlights the drawback and value of the future process.