bluuebunny/crossref_metadata_2025 huggingface dataset:
Stage‐structured ontogeny in resource populations generates non‐additive stabilizing and de‐stabilizing forces in populations and communities
Authors: Glaum Paul , Vandermeer John
Published: April 2021

Demographic heterogeneity influences how populations respond to density dependent intraspecific competition and trophic interactions. Distinct stages across an organism's development, or ontogeny, are an important example of demographic heterogeneity. In consumer populations, ontogenetic stage structure has been shown to produce categorical differences in population dynamics, community dynamics and even species coexistence compared to models lacking explicit ontogeny. The study of consumer–resource interactions must also consider the ontogenetic stage structure of the resource itself, particularly plants, given their fundamental role at the basis of terrestrial food webs. We incorporate distinct ontogenetic stages of plants into an adaptable multi‐stage consumer–resource modeling framework that facilitates studying how stage specific consumers shape trophic dynamics at low trophic levels. We describe the role of density dependent demographic rates in mediating the dynamics of stage‐structured plant populations. We then investigate how these demographic rates interact with consumer pressure to influence stability and coexistence in multiple stage‐specific consumer–resource interactions. Results detail how density dependent effects across distinct ontogenetic stages in plant development produce non‐additivity in the drivers of dynamic stability both in single populations and in consumer–resource settings, challenging the ubiquity of certain traditional ecological dynamic paradigms. We also find categorical differences in the population variability induced by herbivores consuming separate plant stages. Consumer–resource models, such as plant–herbivore interactions, often average out demographic heterogeneity in populations. Here, we show that explicitly including plant demographic heterogeneity through ontogeny yields distinct dynamic expectations for both plants and herbivores compared to traditional consumer–resource formulations. Our results indicate that efforts to understand the demographic effect of herbivores on plant populations may need to also consider the effects of plant demographics on herbivores and the reciprocal relationship between them.
GTR1 and GTR2 transporters differentially regulate tissue‐specific glucosinolate contents and defence responses in the oilseed crop Brassica juncea
Authors: Nambiar Deepti M. , Kumari Juhi , Augustine Rehna , Kumar Pawan , Bajpai Prabodh K. , Bisht Naveen C.
Published: April 2021

GTR1 and GTR2 transporters are components of the source to sink translocation network of glucosinolates, which are major defence metabolites in the Brassicaceae. These transporters can be genetically manipulated for reduction of seed‐glucosinolates without inhibiting glucosinolate biosynthesis, thereby maintaining the inherent defence potential of plants. However, the different roles of GTRs in influencing tissue‐specific distribution of glucosinolates in agriculturally important Brassica crops are yet unknown. Here, we report functional characterization of two groups of glucosinolate transporters (GTR1 and GTR2) from Brassica juncea based on gene expression data, biochemical analysis, gene‐complementation studies in GTR‐deficient mutants and RNAi‐based knockdown followed by insect feeding experiments. Although both GTRs showed ubiquitous expression patterns and broad substrate specificity, the single‐gene knockdown lines displayed different phenotypes. The GTR2‐knockdown plants showed a significant reduction of glucosinolates in seeds and a higher accumulation in leaves and pods, while the GTR1‐knockdown plants displayed a smaller reduction of glucosinolates in seeds and significantly lower glucosinolate levels in leaves. Consequently, knockdown of GTR2 resulted in higher resistance towards the generalist pest, Spodoptera litura. Overall, our study highlights the distinctive roles of B. juncea GTRs in tissue‐specific accumulation of glucosinolates and the potential for manipulating GTR2 for enhanced nutrition and plant defence.
The chaperone‐like protein Cdc48 regulates ubiquitin‐proteasome system in plants
Authors: Rosnoblet Claire , Chatelain Pauline , Klinguer Agnès , Bègue Hervé , Winckler Pascale , Pichereaux Carole , Wendehenne David
Published: April 2021

The degradation of misfolded proteins is mainly mediated by the ubiquitin‐proteasome system (UPS). UPS can be assisted by the protein Cdc48 but the relationship between UPS and Cdc48 in plants has been poorly investigated. Here, we analysed the regulation of UPS by Cdc48 in tobacco thanks to two independent cell lines overexpressing Cdc48 constitutively and plant leaves overexpressing Cdc48 transiently. In the cell lines, the accumulation of ubiquitinated proteins was affected both quantitatively and qualitatively and the number of proteasomal subunits was modified, while proteolytic activities were unchanged. Similarly, the over‐expression of Cdc48 in planta impacted the accumulation of ubiquitinated proteins. A similar process occurred in leaves overexpressing transiently Rpn3, a proteasome subunit. Cdc48 being involved in plant immunity, its regulation of UPS was also investigated in response to cryptogein, an elicitor of immune responses. In the cell lines stably overexpressing Cdc48 and in leaves transiently overexpressing Cdc48 and/or Rpn3, cryptogein triggered a premature cell death while no increase of the proteasomal activity occurred. Overall, this study highlights a role for Cdc48 in ubiquitin homeostasis and confirms its involvement, as well as that of Rpn3, in the processes underlying the hypersensitive response.
Secular trends in muscular fitness from 1983 to 2014 among Slovenian children and adolescents
Authors: Đurić Saša , Sember Vedrana , Starc Gregor , Sorić Maroje , Kovač Marjeta , Jurak Gregor
Published: April 2021

Low physical fitness has been found to be associated with many chronic diseases and medical conditions. Knowledge of secular trends in physical fitness is important to initiate countermeasures for addressing negative trends. The aim of this study was to analyze secular trends in health‐related muscular fitness in Slovenian children and adolescents between 1983 and 2014. Data were collected as part of “The Analysis of Children's Development in Slovenia (ACDSi)” study in 1983, 1993/94, 2003/04, and 2013/14. Anthropometry (body weight, height, BMI, and triceps skinfold) and muscular fitness (standing long jump, bent‐arm hang, and sit‐ups 60 s test) of 18730 (9168 female) students from primary and secondary schools were recorded. The secular trend was analyzed considering anthropometry. The results showed that anthropometric measures had an increasing trend and overall muscular fitness had a decreasing trend. Leg muscle power decreased over the decades in all age groups (relative difference between −1.5% and −2.6%), being more pronounced in boys. Arm muscle strength decreased in two younger age groups (range −21.1% to −42.7%, 6–10, and 11–14 years), but not in the oldest group (15–19 years), where the increase occurred in both genders (0.4% to 9.3%). In terms of decades, the largest negative changes (−30.1%) occurred from 1993/94 to 2003/04 and the smallest changes (−4.2%) from 2003/04 to 2013/14. The overall trend in repetitive core strength surprisingly increased (1.1% to 18.3%). There is a need to promote healthy lifestyles, raise parental awareness and use all government resources to redirect the negative trend in physical fitness.
Impact of Performance‐Based Financing on effective coverage for curative child health services in Burkina Faso: Evidence from a quasi‐experimental design
Authors: Koulidiati Jean‐Louis , De Allegri Manuela , Lohmann Julia , Hillebrecht Michael , Kiendrebeogo Joel Arthur , Hamadou Saidou , Hien Hervé , Robyn Paul Jacob , Brenner Stephan
Published: April 2021

Objective

To evaluate the impact of Performance‐Based Financing (PBF) on effective coverage of child curative health services in primary healthcare facilities in Burkina Faso.

Methods

An impact evaluation of a PBF pilot programme, using an experiment nested within a quasi‐experimental design, was carried out in 12 intervention and 12 comparison districts in six regions of Burkina Faso. Across the 24 districts, primary healthcare facilities (537 both at baseline and endline) and households (baseline = 7978 endline = 7898) were surveyed. Within these households, 12 350 and 15 021 under‐five‐year‐olds caretakers were interviewed at baseline and endline respectively. Linking service quality to service utilisation, we used difference‐in‐differences to estimate the impact of PBF on effective coverage of curative child health services.

Results

Our study failed to detect any effect of PBF on effective coverage. Looking specifically into quality of care indicators, we detected a positive effect of PBF on structural elements of quality of care related to general service readiness, but not on the overall facility quality score, capturing both service readiness and the content of childcare.

Conclusion

The current study makes a unique contribution to PBF literature, as this is the first study assessing PBF impact on effective coverage for curative child health services in low‐income settings. The absence of any significant effects of PBF on effective coverage suggests that PBF programmes require a stronger design focus on quality of care elements especially when implemented in a context of free healthcare policy.
Dynamic Modulus of Staggered Nanocomposites With Different Distributions of Platelets Considering the Interface Stress Effect
Authors: Chao Cezhou , Guo Hanlin , Yan Peng , Dong Leiting
Published: April 2021

Biological staggered composites, like bone, nacre, and dentin, possess the superior capacity of energy dissipation than that of conventional materials. In these nanocomposites, different staggered microstructures are widely observed, for example, symmetric staggered structures with regular platelet layouts and asymmetric staggered structures with offset and stairwise platelet layouts. In addition, the thickness of platelets in these biological materials is at the nanoscale, and the distance between the adjacent ends of platelets is large enough in staggered structures, which indicates the interface effect and tension region (TR) cannot be ignored in staggered nanocomposites. In order to investigate the possible synergistic effect of the platelet layouts, interface effects, and tension region on the dynamic properties of the nanocomposites, a generalized tension-shear chain model (TSCM) with TR is proposed. According to the analytical solutions derived, the staggered nanocomposites with optimal structures can be designed to obtain superior energy dissipation capacity. Considering different loading frequencies in natural environment, the optimal dynamic properties of nacre can be achieved with a regular staggering platelet distribution, while the optimal dynamic properties of bone can be achieved when the number of periodic stairwise staggering platelets is appropriately smaller. These optimal platelet layouts in nacre and bone are consistent with the experimental results reported in many literatures. Therefore, the energy dissipation capacity of staggered nanocomposites can be highly improved, based on the profound understanding of the damping mechanism in biological nanocomposites.
Numerical Simulation of a Three-Dimensional Axisymmetric Hill: Performance Evaluation of Hybrid RANS–LES Models
Authors: Jamal Tausif , Chitta Varun , Walters D. Keith
Published: April 2021

Computational fluid dynamics (CFD) simulation of flow over a three-dimensional (3D) axisymmetric hill presents a unique set of challenges for turbulence modeling. The flow past the crest of the hill is characterized by boundary layer separation, complex vortical structures, and unsteady wake flow. As a result, traditional eddy-viscosity Reynolds-averaged Navier–Stokes (RANS) models have been found to perform poorly for this benchmark test case. Recent studies have focused on the use of large eddy simulation (LES) and hybrid RANS–LES (HRL) methods to improve accuracy. In this study, several different HRL models are investigated, and results from the different models are evaluated relative to each other, to an eddy-viscosity RANS model, and to previously documented high-fidelity LESs and experimental data. Results obtained from the simulations in terms of mean flow statistics, surface pressure distribution, and turbulence characteristics are presented and discussed in detail. Results indicate that eddy-viscosity based HRL models can improve predictions over comparable eddy-viscosity based RANS models such as the shear stress transport (SST) k–ω model used in this study, but only when the development of turbulent velocity fluctuations in the separated shear layer and recirculation region are well resolved.
The Differences in Reading Schematic Drawings of Mechanisms by Expert and Naive Mechanical Designers
Authors: Waldron M. B. , Waldron K. J. , Abdelhamied K.
Published: April 2021

In order to better understand the conceptual design process and to be able to design better computer aids for conceptual design, a qualitative as well as quantitative body of knowledge must be generated regarding the conceptual design process. This paper is a step in that direction. Results on the knowledge and reasoning used by 15 mechanical engineering designers of different levels of expertise in interpreting 8 mechanical engineering drawings are reported. The results partially support the theory that expert designers recognize drawings from knowledge and experience based on functions they have encountered. In addition, two types of reasoning strategies have been identified and studied; namely: forward and inverse reasoning. Inverse reasoning was used more often and more successfully by expert designers.
A Natural Language Approach to Feature Based Modeling
Authors: Gandhi A. , Myklebust A.
Published: April 2021

Traditionally design geometries are represented using orthographic views which require a human being to interpret them and recognize geometric features to evaluate the design. Solid modeling systems have made the task somewhat easier, but they often require tedious and complex operations using simple geometric primitives to create a model assembly. This has led to investigation of modeling systems which allow the creation of assemblies the way engineers conceive them — as features.

To be able to efficiently describe models in terms of features, a rich set of feature descriptors is necessary. An exhaustive study of English words describing form, shape, feature, shape altering transformations and surface conditions was done to establish a wide vocabulary for feature based description.

Classification based on topology and form was done and constraint relations were implemented to differentiate between features. A feature is created from a topological group and a constraint relation. Points are then computed which will be interpolated by uniform rational B-Splines patches. Control points needed to compute the patches are computed from the interpolation points by an inverse relation.

A designer-oriented modeling language, based on simple English syntax, was devised to specify procedures to be executed by the modeler in order to create features using minimal user input.
Pattern Matching Synthesis As an Automated Approach to Mechanism Design
Authors: Hoeltzel D. A. , Chieng W.-H.
Published: April 2021

A new knowledge-based approach for the synthesis of mechanisms, referred to as Pattern Matching Synthesis, has been developed based on committee machine and Hopfield neural network models of pattern matching applied to coupler curves. Computational tests performed on a dimensionally parameterized four bar mechanism have yielded 15 distinct coupler curve groups (patterns) from a total of 356 generated coupler curves.

This innovative approach represents a first step toward the automation of mapping structure-to-function in mechanism design based on the application of artificial intelligence programming techniques.
A Reference Point Algorithm for Planar Path Planning Strategies
Authors: Natarajan R. , Naganathan N. G.
Published: April 2021

This paper presents a simple and efficient algorithm to find a collision free path for a convex polygonal object moving amidst fixed convex polygonal obstacles. Given the initial and the final positions and orientations of the object, the positions and the orientations of the obstacles, the algorithm traces a collision free path. The algorithm identifies reference points at the centroids of these polygonal entities, configures potential candidate obstacles for collision, analyzes the type of collision, and devises a simple method to avoid the obstacles. The reference points help in locating potential obstacles for collision in an environment where large number of obstacles affect computational efficiency and real time implementation. In addition, the computational complexity is found to vary linearly as the number of obstacles increases in the environment. This algorithm is capable of running in real time.
Parameter Sensitivity Analysis in Two-Level Design Optimization
Authors: Li W.-C. , Azarm S.
Published: April 2021

Parameter sensitivity analysis of a two-level design optimization problem can be decomposed into two levels. In the first-level, the sensitivities of the subproblems are calculated separately. In the second-level, the sensitivities obtained for the first-level subproblems are co-ordinated to obtain the overall sensitivity information. Using this approach, we can not only obtain the overall effect that a small change in a parameter has on the optimum solution of a problem (or system) but also its local effects on the subproblems (or subsystems). A simple two-bar truss example demonstrates the approach.
A Hybrid Variable Metric Update for the Recursive Quadratic Programming Method
Authors: Beltracchi T. J. , Gabriele G. A.
Published: April 2021

The Recursive Quadratic Programming (RQP) method has been shown to be one of the most effective and efficient algorithms for solving engineering optimization problems. The RQP method uses variable metric updates to build approximations of the Hessian of the Lagrangian. If the approximation of the Hessian of the Lagrangian converges to the true Hessian of the Lagrangian, then the RQP method converges quadratically. The convergence of the Hessian approximation is affected by the choice of the variable metric update. Most of the research that has been performed with the RQP method uses the Broyden Fletcher Shanno (BFS) or Symmetric Rank One (SR1) variable metric update. The SR1 update has been shown to yield better estimates of the Hessian of the Lagrangian than those found when the BFS update is used, though there are cases where the SR1 update becomes unstable. This paper describes a hybrid variable metric update that is shown to yield good approximations of the Hessian of the Lagrangian. The hybrid update combines the best features of the SRI and BFS updates and is more stable than the SR1 update. Testing of the method shows that the efficiency of the RQP method is not affected by the new update, but more accurate Hessian approximations are produced. This should increase the accuracy of the solutions and provide more reliable information for post optimality analyses, such as parameter sensitivity studies.
Optimum Design of Crown Brakes
Authors: Elbella A. , Seireg A.
Published: April 2021

The use of crown brakes with heat input from both the inner and outer surfaces has been suggested as a means of improving the performance of frictional brakes. This paper presents an algorithm for the design of the optimal thermal load sharing and configuration of the rotor for brakes with different ratios of inner to outer radius. Several illustrative examples are considered and the results show that significant improvement in the performance and weight of the brake rotor can be achieved by this approach.
The Determination of the Probabilistic Properties of Velocities and Accelerations in Kinematic Chains With Uncertainty
Authors: Lee S. J. , Gilmore B. J.
Published: April 2021

A probabilistic model and methods to determine the means and variances of the velocity and acceleration of stochastically-defined planar pin jointed kinematic chains are presented. The presented model considers the effect of tolerances on link length and radial clearance and uncertainty of pin location as a net effect on the link’s effective length. The determination of the mean values and variances of the output variables requires the calculation of sensitivities of secondary variables with respect to the random variables. It is shown that this computation is straightforward and can be accomplished by a conventional kinematic analysis package. Thus, the concepts of tolerance and clearance have been captured by the model and analysis. The only input data is the nominal linkage model and statistical information. The “effective link length” model is shown to be applicable to both analytical solution and Monte Carlo simulation. The results from both methods are compared. This paper solves the higher-order kinematics problem for the probabilistic design analysis of stochastically defined mechanisms.
Robust Mechanical Design Through Minimum Sensitivity
Authors: Belegundu A. D. , Zhang S.
Published: April 2021

The problem of designing mechanical systems or components under uncertainty is considered. The basic idea is to ensure quality control at the design stage by minimizing sensitivity of the response to uncertain variables by proper selection of design variables. This formulation is applied to the design of a brass sleeve which is press fitted over a steel shaft in an uncertain thermal environment. The contact pressure is determined using finite element analysis. By optimizing the shape of the sleeve, the sensitivity of contact pressure with respect to operating temperature is reduced. The minimum sensitivity approach offers a straightforward procedure for robust design and can be implemented in a general manner. It is shown that reduction in sensitivity leads to increase in probability of safety.
A Multi-Objective Design Tree Approach for Optimization Under Uncertainty
Authors: Sandgren E.
Published: April 2021

A means of including uncertainty in the design process is presented. A design tree structure is developed which considers both geometric and topological change as well as material and manufacturing considerations. The design tree is evaluated by formulating and solving a multi-objective nonlinear goal programming problem. This allows for the inclusion of both hard and soft constraint specifications. Design sensitivities with respect to uncertain parameters are included as goals which enables the issue of latitude to be considered as part of the process. An example involving the design of a welded beam structure is presented with uncertainty in both loading condition and material properties. Various alternative designs are considered.
Inverse Dynamic Models Used for Force Control of Compliant, Closed-Chain Mechanisms
Authors: Manko D. J. , Whittaker W. L.
Published: April 2021

A general inverse dynamic model is presented that is applicable to mechanisms incorporating member, joint and base compliance. Previous approaches for defining inverse dynamic models of compliant mechanisms have been approximations or limited to simple mechanism geometries and open-chain mechanisms. Hence, the motivation for a more general approach. Inverse dynamic equations for compliant mechanisms modeled with and without constraint equations are shown to be solvable sets of differential/algebraic equations (DAE’s); relevant characteristics and solutions of DAE systems are discussed. An important application for inverse dynamic models of compliant mechanisms is model-based force control of closed-chain mechanisms. The formulation and solution procedures discussed in this paper have been successfully applied to model legged locomotion on natural terrain.
Implicit Numerical Integration of Constrained Equations of Motion via Generalized Coordinate Partitioning
Authors: Haug E. J. , Yen J.
Published: April 2021

An implicit, stiffly stable numerical integration algorithm is developed and demonstrated for automated simulation of multibody dynamic systems. The concept of generalized coordinate partitioning is used to parameterize the constraint set with independent generalized coordinates. A stiffly stable, backward difference numerical integration algorithm is applied to determine independent generalized coordinates and velocities. Dependent generalized coordinates, velocities, and accelerations, as well as Lagrange multipliers that account for constraints, are explicitly retained in the formulation to satisfy all of the governing kinematic and dynamic equations. The algorithm is shown to be valid and accurate, both theoretically and through solution of a numerical example.
Synthesis of Geometric Primary Circles of Externally Meshed Skew-Axes Gears
Authors: Abadjiev V. , Petrova D.
Published: April 2021

What are considered are geometric primary circles of gears which transform rotations between fixed skewed axes with a constant speed ratio. These imaginary circles differ from the pitch ones of the gears with parallel or intersecting axes. It seems they are used succeessfully for the first time as a start point in designing hyperbolic gears. Both the diameters and the mutual position parameters of the geometric primary circles are needed when gear over-alls and mounting distances as well as teeth geometry are determined.
A New Probabilistic Method for the Performance Evaluation of Manipulators: Part I — Methodology
Authors: Rastegar J. , Singh J. R.
Published: April 2021

A totally new probabilistic method is introduced which can be used to obtain a global map of the distribution of the velocity and force transmission characteristics of robotic manipulators. The method yields the global distributions of volumes of the velocity and force ellipsoids, the eigenvectors, the eigenvalues, and the condition numbers. It utilizes the most basic definition of the properties of the mapping functions between the joint coordinates and the Cartesian (task) coordinates. The method is extremely simple, numerical in nature, and readily implementable on a computer. It requires very simple and limited analytical formulations. No inverse calculations are involved. The method furnishes a very simple and effective tool for solving a number of synthesis, performance evaluation, and task planning problems. In Part II of this paper, the method is utilized for optimal positioning of task spaces within workspaces of manipulators. Several examples are presented.
Comparison of Methods for Determining Screw Parameters of Finite Rigid Body Motion From Initial and Final Position Data
Authors: Fenton R. G. , Shi X.
Published: April 2021

Five methods for determining the screw parameters of finite rigid body motion using position data of three non-collinear points are compared on the basis of their efficiency, accuracy, and sensitivity to data error. It is found that the method based on Rodrigues’ Formula (Bottema & Roth’s method) is the most efficient. Angeles’ method and Laub & Shiflett’s method provide approximately the same level of accuracy, which is superior to that of the other methods. In terms of sensitivity, Bottema & Roth’s method is preferable On the basis of this study it is recommended that Bottema & Roth’s method to be used if uncertainty exists in the data since it can provide a solution efficiently, accurately, and it is the least sensitive to data error.
Electrical characterization of gate stack charge traps in floating body gate-all-around field-effect-transistors
Authors: Nguyen Manh-Cuong , Nguyen An Hoang-Thuy , Yim Jiyong , Nguyen Anh-Duy , Kim Mingyu , Kim Jeonghan , Beak Jongyeon , Choi Rino
Published: April 2021

Individual charge traps in the gate stack of gate-all-around field-effect-transistors have been identified from their random telegraph noise (RTN) characteristics in the time and frequency domains. The energy level and depth location of the corresponding charge traps were extracted from capture/emission time constant and corner frequency. The charge traps were determined to be the excited states of oxygen vacancies in the dielectric located 3 nm away from the interface. Both the time domain and frequency domain RTN measurements lead to an identical result.
Southern Ocean anthropogenic carbon sink constrained by sea surface salinity
Authors: Terhaar Jens , Frölicher Thomas L. , Joos Fortunat
Published: April 2021

Observed sea surface salinity constrains past and future anthropogenic carbon uptake in the Southern Ocean.
Strain-driven autonomous control of cation distribution for artificial ferroelectrics
Authors: Sohn Changhee , Gao Xiang , Vasudevan Rama K. , Neumayer Sabine M. , Balke Nina , Ok Jong Mok , Lee Dongkyu , Skoropata Elizabeth , Jeong Hu Young , Kim Young-Min , Lee Ho Nyung
Published: April 2021

Strain provides autonomous control of atomic building blocks for the synthesis of functional materials.
Increasing Pleistocene permafrost persistence and carbon cycle conundrums inferred from Canadian speleothems
Authors: Biller-Celander Nicole , Shakun Jeremy D. , McGee David , Wong Corinne I. , Reyes Alberto V. , Hardt Ben , Tal Irit , Ford Derek C. , Lauriol Bernard
Published: April 2021

Permafrost thaw decreased over the Pleistocene yet had little apparent effect on interglacial greenhouse gas concentrations.
Hard questions for soft robotics
Authors: Hawkes Elliot W. , Majidi Carmel , Tolley Michael T.
Published: April 2021

How can the field of soft robotics have impact in the next decade?
External Evaluation of Two Pediatric Population Pharmacokinetics Models of Oral Trimethoprim and Sulfamethoxazole
Authors: Wu Yi Shuan S. , Cohen-Wolkowiez Michael , Hornik Christoph P. , Gerhart Jacqueline G. , Autmizguine Julie , Cobbaert Marjan , Gonzalez Daniel
Published: April 2021

The antibiotic combination trimethoprim (TMP)-sulfamethoxazole (SMX) has a broad spectrum of activity and is used for the treatment of numerous infections, but pediatric pharmacokinetic (PK) data are limited. We previously published population PK (popPK) models of oral TMP-SMX in pediatric patients based on sparse opportunistically collected data (POPS study) (J.
Recombinant Herpesvirus Vectors: Durable Immune Responses and Durable Protection against Simian Immunodeficiency Virus SIVmac239 Acquisition
Authors: Castro Isabelle M. , Ricciardi Michael J. , Gonzalez-Nieto Lucas , Rakasz Eva G. , Lifson Jeffrey D. , Desrosiers Ronald C. , Watkins David I. , Martins Mauricio A.
Published: April 2021

We report on the long-term follow-up of a group of rhesus macaques (RMs) that received an AIDS vaccine regimen and were subsequently protected against rectal acquisition of simian immunodeficiency virus (SIV) infection. The vaccination regimen employed included a live recombinant herpesvirus vector that establishes persistent infection in RMs.
Lost Small Envelope Protein Expression from Naturally Occurring PreS1 Deletion Mutants of Hepatitis B Virus Is Often Accompanied by Increased HBx and Core Protein Expression as Well as Genome Replication
Authors: Fu Shuwen , Zhang Jing , Yuan Quan , Wang Qianru , Deng Qiang , Li Jisu , Xia Ningshao , Wang Yongxiang , Wen Yumei , Tong Shuping
Published: April 2021

Expression of hepatitis B e antigen (HBeAg) and overproduction of HBsAg by wild-type HBV are implicated in the induction of immune tolerance to achieve chronic infection. How HBV survives the subsequent immune clearance phase remains incompletely understood.
Inhibitors of Coronavirus 3CL Proteases Protect Cells from Protease-Mediated Cytotoxicity
Authors: Resnick Samuel J. , Iketani Sho , Hong Seo Jung , Zask Arie , Liu Hengrui , Kim Sungsoo , Melore Schuyler , Lin Fang-Yu , Nair Manoj S. , Huang Yaoxing , Lee Sumin , Tay Nicholas E. S. , Rovis Tomislav , Yang Hee Won , Xing Li , Stockwell Brent R. , Ho David D. , Chavez Alejandro
Published: April 2021

Multiple coronavirus pandemics have occurred over the last 2 decades. This has highlighted a need to be proactive in the development of therapeutics that can be readily deployed in the case of future coronavirus pandemics.
Draft Genome Sequences of Three Strains of Campylobacter jejuni Isolated from Patients with Guillain-Barré Syndrome in Bangladesh
Authors: Islam Zhahirul , Nabila Fahmida Habib , Asad Asaduzzaman , Begum Ruma , Jahan Israt , Hayat Shoma , Endtz Hubert P.
Published: April 2021

Campylobacter jejuni
is the pathogen most commonly associated with Guillain-Barré syndrome (GBS). The present work describes the draft genome sequences of 3
C. jejuni
strains, BD39, BD67, and BD75, isolated from stool specimens of
C. jejuni
-triggered patients with GBS using Illumina technologies.
Draft Genome Sequence of Clostridium beijerinckii Strain mbf-VZ-132, Isolated from an Environmental Soil Sample
Authors: Thieme Nils , Liebl Wolfgang , Zverlov Vladimir V.
Published: April 2021

Clostridium beijerinckii
strain mbf-VZ-132 was isolated from soil in Freising-Weihenstephan (Bavaria, Germany). The 16S rRNA gene sequence showed a 99.9% sequence identity to
Clostridium diolis
DSM 15410, which was recently reclassified as
C. beijerinckii
. In this study, we present the draft genome sequence of
C. beijerinckii
mbf-VZ-132, based on PacBio sequencing.
NanH Is Produced by Sporulating Cultures of Clostridium perfringens Type F Food Poisoning Strains and Enhances the Cytotoxicity of C. perfringens Enterotoxin
Authors: Li Jihong , McClane Bruce A.
Published: April 2021

Clostridium perfringens
type F strains cause the second most common bacterial foodborne illness in the United States.
C. perfringens
enterotoxin (CPE) is responsible for the diarrhea and cramping symptoms of this food poisoning (FP). Previous studies showed that NanI sialidase can enhance CPE activity
in vitro
.
Laryngotracheal and pharyngoesophageal traumatic injuries from US military operations in Iraq and Afghanistan, 2003–2017
Authors: Coulter Michael , Mickelson R C , Dye J L , Myers E E , Ambrosio A A
Published: April 2021

Introduction

Laryngotracheal and pharyngo-oesophageal trauma present military providers with especially difficult, life-threatening challenges. Although effective treatment strategies are crucial, there is no clear consensus. This study of combat injuries from Iraq and Afghanistan describes initial treatment outcomes.

Methods

US service members who sustained ‘laryngotracheal’ and ‘pharyngoesophageal’ injuries while deployed in military operations from 2003 to 2017 were identified from the Expeditionary Medical Encounter Database. Those with inhalation or ingestion injuries and an Injury Severity Score (ISS) <16 were excluded. Data on demographics, survival, mechanism and type of injury and diagnostic and therapeutic intervention were recorded.

Results

A total of 111 service members met inclusion criteria. Nearly one-third (32.4%) were killed in action (KIA) or died of wounds (DoW). Fatality was not significantly associated with age, theatre of operation, type of injury or mechanism of injury, but was associated with a higher ISS and those in the Marines. Although survival rates were not significantly different, the frequency of these injuries decreased after the introduction of cervical collar protection in 2007. Of those who DoW or survived, 41.1% required a surgical airway. Tracheobronchoscopy was performed in 25.6%, oesophagoscopy in 20.0% and oesophagram in 6.7%. Of the 85 with penetrating neck injuries, 43 (50.6%) underwent neck exploration, in which 31 (72.1%) required intervention.

Conclusions

Severe laryngotracheal and pharyngo-oesophageal injuries have a high fatality rate and demand prompt treatment from skilled providers. Further work will elucidate preventive measures and clear management algorithms to optimise outcomes.
Transcatheter mitral valve repair: an overview of current and future devices
Authors: De Backer Ole , Wong Ivan , Taramasso Maurizio , Maisano Francesco , Franzen Olaf , Søndergaard Lars
Published: April 2021

The field of transcatheter mitral valve repair (TMVr) for mitral regurgitation (MR) is rapidly evolving. Besides the well-established transcatheter mitral edge-to-edge repair approach, there is also growing evidence for therapeutic strategies targeting the mitral annulus and mitral valve chordae. A patient-tailored approach, careful patient selection and an experienced interventional team is crucial in order to optimise procedural and clinical outcomes. With further data from ongoing clinical trials to be expected, consensus in the Heart Team is needed to address these complexities and determine the most appropriate TMVr therapy, either single or combined, for patients with severe MR.
ELECTRONIC AND OPTICAL MODIFICATION OF ORGANIC-HYBRID PEROVSKITES
Authors: KAFFAH SILMI , DIGUNA LINA JAYA , ABU BAKAR SURIANI , BIROWOSUTO MUHAMMAD DANANG , ARRAMEL
Published: April 2021

Renewed interest has brought significant attention to tune coherently the electronic and optical properties of hybrid organic–inorganic perovskites (HOIPs) in recent years. Tailoring the intimate structure–property relationship is a primary target toward the advancement of light-harvesting technologies. These constructive progresses are expected to promote staggering endeavors within the solar cells community that needs to be revisited. Several considerations and strategies are introduced mainly to illustrate the importance of structural stability, interfacial alignment, and photo-generated carriers extraction across the perovskite heterostructures. Here, we review recent strides of such vast compelling diversity in order to shed some light on the interplay of the interfacial chemistry, photophysics, and light-emitting properties of HOIPs via molecular engineering or doping approach. In addition, we outline several fundamental knowledge processes across the role of charge transfer, charge carrier extraction, passivation agent, bandgap, and emission tunability at two-dimensional (2D) level of HOIPs/molecule heterointerfaces. An extensive range of the relevant work is illustrated to embrace new research directions for employing organic molecules as targeted active layer in perovskite-based devices. Ultimately, we address important insights related to the physical phenomena at the active molecules/perovskites interfaces that deserve careful considerations. This review specifically outlines a comprehensive overview of surface-based interactions that fundamentally challenges the delicate balance between organic materials and perovskites, which promotes bright future of desired practical applications.
Porphyrin-based MOFs as heterogeneous photocatalysts for the eradication of organic pollutants and toxins
Authors: Harvey Pierre D.
Published: April 2021

Water and air pollution are among the major environmental challenges of this era. Waste management, economic sustainable development and renewable energy are unavoidable concomitant considerations. Over the past five years, nanosized metal-organic frameworks (nano-MOFs) have been developed for the elimination of pollutants in wet media and air-born toxins using the highly efficient reactive oxygen species (ROS) of type I (H2O2, •OH, O[Formula: see text] and of type II (1O[Formula: see text]. The ROS are catalytically and efficiently generated through photosensitization, and porphyrins and metalloporphyrins are pigments of choice for this purpose. This short review summarizes the fundamentals of ROS generation by porphyrin-based nano-MOFs (mainly through the formation of ROS type II) and their composites (leading to ROS type I), which includes energy and electron transfer processes, and their applications in these environmental issues.
Quantitative Detection of Trace Copper by Using Graphene Oxide and X-Ray Fluorescence Spectroscopy
Authors: Liu Jia-Hui , Zhu Junhao , Wang Na , He Fei , He Luanying , Song Haihong , Dong Yiyang , Zhang Li , Wang Shihui
Published: April 2021

The X-ray fluorescence spectroscopy (XRF) has been widely applied on the analysis of elements. The traditional sample preparation needs a large sample weight and high temperature/pressure. To overcome these drawbacks, we used graphene oxide (GO) as a matrix for the carry of trace metal (copper was used as a model) and constructed a sandwich-layered GO which carried trace copper nanomembrane (SL-GO-Cu). After the optimization of filter membranes, nanomembrane composition and GO content in the bottom layer of SL-GO-Cu, the limit of detection (LOD) of SL-GO-Cu achieves 2.99 [Formula: see text]g/g. The LOD is ca. 1/3 or 1/1923 of the traditional melt pellets of trace CuO (MPT-Cu) and tabletting pellets of trace CuO (TPT-Cu) methods, respectively. The SL-GO-Cu is independent of CuO size, but varies with different Cu compounds. Recoveries of all the SL-GO-Cu samples prepared above are higher than 94% and do not show significant difference. In summary, the SL-GO-Cu is a promising method for the efficient and economical determination of trace elements.
Uniquely colorable graphs with equal chromatic and game chromatic numbers
Authors: Matsumoto Naoki
Published: April 2021

In this paper, we characterize uniquely colorable graphs with equal chromatic and game chromatic numbers.
Additive manufacturing of hydroxyapatite and its composite materials: A review
Authors: Yan Chunze , Ma Gao , Chen Annan , Chen Ying , Wu Jiamin , Wang Wei , Yang Shoufeng , Shi Yusheng
Published: April 2021

Hydroxyapatite (HA) is a promising biomaterial for tissue engineering scaffolds due to its similar performance and composition to natural bone. However, the brittleness and poor toughness of pure HA limit its clinical application. Therefore, a lot of HA composites have been prepared to improve their mechanical performance. Fabricating complex and customized tissue engineering HA scaffolds have a very high requirement for manufacturing processes. It is difficult to fabricate ideal HA porous structures for artificial bone implants using traditional manufacturing processes, such as plasma spraying–sintering, and injection forming. Additive manufacturing (AM) could make three-dimensional physical parts with complex structures directly from computer-aided-design (CAD) models in a layer-by-layer way, and therefore show unique advantages in fabricating bone tissue engineering scaffolds with complex external shape and internal microporous structures. This paper reviews the state of the art for the preparation and AM process of HA and its composite materials, and raises the prospects for this research field.
Computational Design of a Potential Therapeutic Peptide Against Spike Protein of SARS-CoV-2
Authors: Alibakhshi Abbas , Ahangarzadeh Shahrzad , Beikmohammadi Leila , Soltanmohammadi Behnoush , Bahrami Armina Alagheband , Ranjbar Mohammad Mehdi , Mohammadi Elmira
Published: April 2021

SARS-CoV-2 entrance to the host cells is started by the interaction between receptor binding domain (RBD) of the spike (S) protein on the virus with the angiotensin-converting enzyme 2 (ACE2) receptor which is very important in the onset of viral infection. Interference with this interaction can be a promising way to prevent Covid-19 infection. In this study, a novel potential therapeutic peptide was designed in silico based on the key interacting amino acids of ACE2 against SARS-CoV-2 S protein. In our computational analysis, a peptide consisting of residues 19–48 of ACE2 was chosen as the wild-type peptide. Based on this peptide, six mutant peptides (Mu_P1-6) were designed and then assessed in term of interaction with S protein. The result of protein-peptide docking by HADDOCK web server and then immunological analysis by SVMTriP epitope prediction tool leads to choose Mu_P3 as the best mutant. Molecular dynamics simulations of wild-type peptide-S protein complex and Mu_P3-S protein complex, showed Mu_P3 has better interaction with S protein than wild type peptide (interaction energies [Formula: see text] vs. [Formula: see text] (kJ/mol)) which can be a potential therapeutic peptide for Covid-19 pandemic.
A Famine of Riches in Scholarly Publication
Authors: Stafford Tom
Published: April 2021

I have been editing for a while. Long enough to have witnessed the evolution from pre-digital journals to the post-digital pure play. I negotiated and obtained the first online review system for this fine journal, back in 2006 when I was building my first proposal to edit The DATA BASE for Advances in Information Systems. I felt at the time that I might be a tad late coming to the digital field, seeing that the association I belonged to had already launched two digital pure-play publications which appeared to be destined for notice.
Understanding Customers' Continuance Intention
Authors: Kaba Bangaly
Published: April 2021

The purpose of this study is to understand the difference between Internet users' continuing use behavior in the context of digital inequality. Data were collected through a survey of Internet users in the Ivory Coast. The structural equation modeling technique was used to test the research hypothesis. This study showed empirically that concern over information and communication technologies (ICT) access as an explanation for digital inequality should be toned down. This research suggests emphasizing alternative factors to explain Internet sustained use intention by underprivileged individuals, including normative beliefs. The results will help internet service providers, governments, and international aid agencies to better understand users' behaviors or reactions to ICT available to them. This understanding provides a foundational platform upon which viable and effective information technology-enabled solutions and policies can be conceptualized and implemented. This study is one of the few that integrate three salient beliefs to differentiate ICT use continuance intention in the context of digital inequality.
The Philosopher's Corner
Authors: Mendling Jan , Berente Nicholas , Seidel Stefan , Grisold Thomas
Published: April 2021

In an effort to contribute to the recent debate around epistemological and methodological anarchism inspired by the thinking of Paul Feyerabend, we reflect on Habermas's pragmatist perspective of social science. We argue that the information systems field instantiates a sort of pluralism that goes beyond the relativistic conclusions of Feyerabend. This is evident through the different traditions of research into business processes and organizational routines. There is a healthy diversity of epistemological and methodological approaches in this research. Accompanying this diversity is an openness to novelty and change. Yet, at the same time, this does not necessitate the abandonment of rigor and a cumulative tradition implied by "anything goes." Anything does not go, and that's a good thing. There is not a singular, hegemonic approach to what constitutes strong information systems research, but neither have we devolved into anarchy.
Language support for parallel and distributed computing
Authors: Chard Kyle , Muns James , Wai Richard , Taft S. Tucker
Published: April 2021

Language constructs that support parallel computing are relatively well recognized at this point, with features such as parallel loops (optionally with reduction operators), divide-and-conquer parallelism, and general parallel blocks. But what language features would make distributed computing safer and more productive? Is it helpful to be able to specify on what node a computation should take place, and on what node data should reside, or is that overspecification? We don't normally expect a user of a parallel programming language to specify what core is used for a given iteration of a loop, nor which data should be moved into which core's cache. Generally the compiler and the run-time manage the allocation of cores, and the hardware worries about the cache. But in a distributed world, communication costs can easily outweigh computation costs in a poorly designed application. This panel will discuss various language features, some of which already exist to support parallel computing, and how they could be enhanced or generalized to support distributed computing safely and efficiently.