bluuebunny/crossref_metadata_2025 huggingface dataset:
Propagation of short pulse through arbitrary relaxing media with resonant properties. New approach
Authors: Maksimov German A. , Larichev Vladimir A.
Published: July 2002

The new analytical representation of the fundamental solution (Green’s function) describing the short pulse propagation in a medium with a single process of resonant relaxation is presented in the report. This analytical solution is based on the generalized local response function of linear media [V. A. Larichev and G. A. Maksimov, Acoust. Phys. 44, No. 46, 709–716 (1998)]. It contains well-known Lorentz and Ziner models of relaxing media, like particular cases. The changing of the pulse shape at propagation, described by the obtained solution, shows a variety of forms of pulse propagation and general lows of pulse dynamics beginning from pure relaxation behavior and up to the resonant one. [Work supported by ISTC in Moscow.]
Grouping and adaptation in modulation detection interference
Authors: Oxenham Andrew J. , Dau Torsten
Published: July 2002

Modulation detection interference (MDI) can be reduced by gating the masker and signal carriers asynchronously, possibly due to grouping effects. However, as both carriers are generally modulated throughout their presentation, two other factors may also play a role: First, the response to modulation may adapt, thereby reducing the effective masker modulation depth prior to signal presentation. Second, analogous to intensity perception, a dynamic change in modulation depth (increment detection) may be easier to detect than an overall difference across two presentations (level discrimination). A MDI paradigm with 1- and 4.3-kHz carriers was used. The 16-Hz sinusoidal signal modulation was masked by noise modulation with a passband from 8 to 24 Hz. In one experiment, the gating synchrony of carrier and modulator were independently varied. In another experiment, both masker and signal modulated a single 4.3-kHz carrier, with gating synchrony between masker and signal varied. Results suggest that the asynchronous gating of either the carriers or modulators alone is not sufficient to produce a release from MDI. Thresholds were higher for the single carrier than for the two carriers, and gating the masker modulation on prior to the signal did not improve performance. [Supported by NIDCD and Max Kade Foundation.]
Coincidence network for estimating tone frequency from firing-rate wavelength
Authors: Thongprasirt Rachod , Wilson Timothy A.
Published: July 2002

A signal-processing auditory model was constructed. It was composed of four stages: the cochlear-filtering stage, the transduction stage, the neural-adaptation stage, and the spike-generation stage. A linear fourth-order gammatone filter with traveling-wave delay was used in the cochlear-filtering stage. The output from the neural adaptation was the rate of spike generation. The cochlear wavelength was defined as the distance between successive peaks of the cochlear traveling wave. It was shown that for a given tone input there is an approximately linear relationship between the cochlear wavelength and the peak location of the cochlear traveling wave. Furthermore, this linear relationship still holds, within the low-frequency range, between the firing-rate wavelength and its peak location. A simple coincidence-counting network was constructed to estimate the input frequency in the low-frequency range. Each coincidence element had inputs from two different places along the cochlear length. Its output was then processed by another neural level. The results of the frequency estimation will be presented.
Acoustic wave reflection from a rough surface over a random fluid half-space
Authors: Liu Jin-Yuan
Published: July 2002

Plane-wave reflection from a rough surface overlying a fluid half-space with a sound-speed distribution subject to random perturbation is considered. A theory based upon a boundary perturbation method in conjunction with a formulation derived from Green’s function for the coherent field in the random medium has been applied to a typical oceanic environment to study its effects on the plane-wave reflection. By considering the coherent field itself, it may be obtained straightforwardly through a procedure consistent with the formalisms currently employed in rough surface scattering. The results show that both the rough surface and medium inhomogeneities may reduce the plane-wave reflection; however, the characteristics of the curves representing their effects are different, enabling us to identify the dominant scattering mechanism. The results for the coherent reflection due to individual scattering mechanism are compatible to those found in the existing literature. [Work supported by NSC of Taiwan, R.O.C.]
Multiple Doppler shifts in the field scattered from an object moving in a horizontally stratified waveguide
Authors: Lai Yisan , Makris Nicholas C.
Published: July 2002

A method is developed to solve the problem of bistatic scattering from a horizontally moving object in a horizontally stratified waveguide. The target motion induces both frequency and wave-number shifts in the scattered field. For long-range propagation in a waveguide, the incident field can be decomposed into a discrete set of plane waves that propagates at the equivalent angles of the trapped modes. Doppler effects in the scattered field depend on the direction of the incident and scattered field with respect to the direction of motion. Each incident mode contributes a number of Doppler-shifted scattered components. For a monochromatic source that excites N incident modes in the waveguide, there will be roughly N2 distinct harmonic components in the scattered field. The effect of these multiple Doppler shifts on the scattered field will be illustrated through a number of canonical examples.
Six-year records of low-frequency ambient sound in the North Pacific
Authors: Andrew Rex K. , Howe Bruce M. , Mercer James A.
Published: July 2002

Spectra of ambient sound have been collected over the past 6 years at 13 locations around the North Pacific. Data were collected on single hydrophones for 3 min every 6 min and power spectra in 1-Hz bands from 0–500 Hz were calculated. Results from this 6-year data set are presented including probability statistics (e.g., the fraction of time a sound level is exceeded), whale, ship, and wind statistics, and long-term trends. These results build on those presented previously for 2 years [Curtis et al., J. Acoust. Soc. Am. 106, 3189–3200 (1999)]. [Work supported by Ocean Acoustics, ONR.]
Kinetics of Stress Relaxation in Metals
Authors: Wilson J. F. , Wilson N. K.
Published: July 2002

The phenomenon of stress relaxation, the time decrease of internal stress due to localized flow in a solid under constant uniaxial strain, is viewed in terms of present kinetic theories and available data for metals. Rate equations for shear flow, derived from molecular models of liquids and gases, are reviewed briefly. Combined with the theory of elasticity, these equations are shown to be identical to the classical Maxwell model and to the empirical logarithmic form in limiting cases for stress relaxation in solids. Without reference to the specific details of the localized flow, the general equations are found to correlate uniaxial data for many types of steels, copper, aluminum, magnesium, and lead for various temperatures and stress levels. In all of the data, one characteristic controlling reaction is found, and in some cases a secondary reaction dependent upon the level of the uniaxial prestress is also found. For nonaging metals, the data fit equations in which the relaxation stress approaches zero asymptotically in time. A simple modification of the rate equations is made so that an age-hardening metal can approach a nonzero stress during relaxation. Prestress is used as a controlling variable in correlating data for uniaxial stress relaxation. Apparent heats and entropies of activation are calculated for Inconel and copper at elevated temperatures. For nearly all metals, the apparent free energy of activation for the controlling reaction in the relaxation process decreases slightly as the prestress is increased.
A Relationship between Molecular Weight Distribution and Non-Newtonian Flow for Polyisobutenes
Authors: Porter Roger S. , Cantow Manfred J. R. , Johnson Julian F.
Published: July 2002

In recent years it has been demonstrated widely that relationships do exist between molecular weight distribution and the non-Newtonian flow of linear amorphous polymers. Variations in distribution cause marked deviations from general reduced variable curves for non-Newtonian flow. This conclusion means that reduced variables must involve more than a single molecular weight average. This complexity has been evaluated in this study by equating shear relaxation spectra for polymer solutions to their respective molecular weight distributions. Molecular weight distributions have been generated by column fractionation, measured by gel permeation chromatography, and expressed in terms of their standard deviations. The distributions, expressed in the common form of Mw/Mn, ranged from 3.07 to 1.01. The procedure has been successfully applied to non-Newtonian flow curves for concentrated solutions of polyisobutenes. This new relationship may be suitable for expressing the non-Newtonian flow of other linear amorphous polymers. A general approach of this type is of value for predicting and tailoring the flow properties of polymers.
Theoretical Analysis of Pressure Drop in the Laminar Flow of Fluid in a Coiled Pipe
Authors: Larrain J. , Bonilla C. F.
Published: July 2002

A series solution with terms depending on the curvature of the pipe is presented for the coiling effect. Because of its slow convergence the series is most useful only at Dean numbers below about 16. However, this is the normal range for viscometry with coiled capillaries. Theoretical analysis is also appropriate in this range because as the excess pressure drop due to coiling decreases it is more difficult to measure accurately by experiment. A previously unreported finding is made, that at very low flows all coiled capillaries yield a lower pressure drop than a straight capillary of the same axial length. However, this does not detract from the utility of coiled capillaries for high precision viscometry.
Accounting for lubricant shear thinning in the design of short journal bearings
Authors: Rastogi A. , Gupta R. K.
Published: July 2002

Equations are derived for analyzing the flow of inelastic, non-Newtonian lubricants in short journal bearings. A realistic bearing geometry is used along with the power-law fluid model to study the influence of lubricant shear thinning on the load-bearing capacity under isothermal conditions. The results are useful for designing journal bearings to achieve desired values of the friction coefficient or the minimum oil film thickness for steady as well as time-varying loads. These results show that the idea of using the viscosity corresponding to the shear rate in the bearing for evaluating engine oil flow characteristics is a reasonable one.
Single-point correction for parallel disks rheometry
Authors: Carvalho M. S. , Padmanabhan M. , Macosko C. W.
Published: July 2002

The nonhomogeneous nature of the flow in the parallel disks rheometer necessitates the differentiation of the measured quantities (torque and normal force) with respect to the shear rate at the disk rim. Commercial instruments do not calculate true material functions online, rather they report apparent Newtonian values, i.e., ones obtained assuming the material functions are constants. In this work, we present a single-point correction technique to obtain approximate values for material functions without numerical differentiation. The advantage of the single-point correction method is that it gives more accurate results than the apparent Newtonian values and it takes less time than numerical differentiation. This can, therefore, be useful in quality control laboratories and for process-line measurements where reasonably accurate data are needed in a short time. A single-point correction is applied to the parallel disks device for the shear viscosity and a new correction method for the normal stress coefficients is also developed. The accuracy of these approximate methods is tested with experimental results for a polymer melt and a polymer solution. The correction for both shear viscosity η and normal stress coefficient Ψ≡Ψ1−Ψ2 avoids the numerical differentiation of the data and can be easily implemented in software that provide online material functions.
Piston-driven flow of highly concentrated suspensions
Authors: Lukner Ralf B. , Bonnecaze Roger T.
Published: July 2002

The piston-driven flow of highly concentrated suspensions (55% or 59% by volume solids) of dense spheres was investigated as a function of piston speed, liquid viscosity, particle material, and particle size. The drag of the suspension was found to be independent of piston speed for 0.5 and 1.4 mm glass or PMMA spheres in liquids with viscosities from 1 to 641 cP. For suspensions prepared from 55 000 cP liquids, the drag was piston speed dependent. In the speed-independent range, the drag decreased with increasing liquid viscosity and was significantly larger than that predicted by existing models for suspensions. In the speed-dependent range, the drag increased with viscosity. A macroscopic model based on lubricated frictional contacts between the particles and the wall was successfully applied to correlate the shear-rate independent data for suspensions prepared from liquids with viscosities from 1 to 641 cP. It was possible to estimate the drag of the suspensions prepared from 1.4 mm spheres by using tabulated friction coefficients and the macroscopic model. Results from flow visualization confirmed the presence of significant wall slip and the presence of fountain flow.
A material system with integrated fault diagnosis and feedback controlled self‐healing
Authors: Kuponu Oluwafemi Sedoten , Kadirkamanathan Visakan , Bhattacharya Bishakh , Pope Simon Alexander
Published: June 2022

Two significant drawbacks of current self‐healing materials are that they are: (1) Passive and as such do not guarantee a match between the healing and damage rate; (2) Not monitored during and after healing, so that the performance of the healed material is not known without retrospective offline testing. As a consequence their application is currently limited in some sectors, such as the aerospace sector where high performance needs to be guaranteed within strict guidelines. This article proposes the first active self‐healing material that integrates with control and fault diagnosis to provide a system with a desired healing response. A fault diagnosis algorithm using supervised regression is used to estimate the measure of damage. Then based on this estimate, adaptive feedback control is used to ensure a match between the healing response and the damage rate, while taking into account the nonlinear system dynamics and uncertainty. The system is demonstrated in simulation using a self‐healing material based on piezoelectricity and electrolysis. This shows the ability of the integrated subsystems to tackle these two significant drawbacks of most current self‐healing systems and will benefit applications with strict performance requirements, or systems operating under harsh conditions or that are remotely accessed.
Improve the Photocatalytic Hydrogen Production Using ZnS@ZnO Twin‐Junction Structure with Isoelectronic Traps
Authors: Li Zehan , Huang Meiling , Li Yanlu , Ai Zizheng , Zhang Kang , Yao Xiaogang , Kong Zhen , Shao Yongliang , Wu Yongzhong , Hao Xiaopeng
Published: June 2022

The effective separation of carriers with prolonged lifetime is important to improve the activity of photocatalytic water splitting hydrogen production. In this work, the separation of electron‐hole pairs is achieved by ZnS@ZnO twin‐junction with isoelectronic traps, with which the corresponding doubled fluorescence lifetime is achieved. The existence of isoelectronic traps is further confirmed by the first principles calculations that prove the coincidence between impurity level position and Fermi level. The all‐important role of isoelectronic traps has almost never been mentioned and demonstrated in photocatalysis so far. Moreover, it is favorable for photocatalysis that the migration direction of carriers in II‐type ZnS@ZnO is consistent with the trapped behavior under the effect of isoelectronic traps, which shows a leading H2 production activity of 1628 µmol h‐1 g‐1 under simulated sunlight. What's more, the impurity levels formed by sulfur in the middle part ZnO1‐xSx enable visible light to be absorbed, neither ZnS nor ZnO would otherwise absorb visible light, and the H2 production activity reaches 380 µmol h‐1 g‐1. This will provide guidance to construct composite structure for wide bandgap semiconductors in the future.
Chemical Control Over Optical Trapping Force at an Interface
Authors: Bresolí‐Obach Roger , Nonell Santi , Masuhara Hiroshi , Hofkens Johan
Published: June 2022

So far, the optical trapping potential is controlled by tuning the physical conditions of the system. Herein, for the first time, an approach, in which the induced optical force or optical potential is controlled, by an external chemical stimulus, is reported. The key to realize this is to design an optical trapping condition in conjunction with resonant excitation, the so‐called optical resonance effect (ORE). For this purpose, phenalenone, a well‐known triplet photosensitizer, is embedded inside polystyrene particles. The optical resonance effect is achieved through a two‐laser system: a 405 nm widefield laser to excite the phenalenone molecules to T1 state and a 488 nm trapping laser to induce the T1–Tn–T1 resonance cycle. Thus, the triplet state is mainly responsible for the optical force enhancement. Since oxygen is an excellent triplet quencher, the triplet populations, and hence, the optical force is controlled by changing the dissolved oxygen concentration. The results presented here pave the way to chemically control the optical force through ORE with promising applications in several research fields ranging from physics to biology.
Overlooked tools for studying soil nitrogen depolymerization: Aminopeptidase assays using nitroanilide substrates
Authors: Margenot Andrew J , Daughtridge Rachel C
Published: June 2022

Aminopeptidases are one of the extracellular hydrolytic enzymes that catalyze organic nitrogen (N) depolymerization and are commonly assayed using fluorogenic substrates. However, chromogenic substrates based on para‐nitroaniline (pNA) developed for the study of aminopeptidases in the 1960s have been underutilized. To gauge the use of pNA substrates to assay soil aminopeptidases, a systematic literature review was conducted. We identified 61 studies that were nearly all limited to measuring leucine and/or glycine aminopeptidases, despite the commercial availability of at least six other aminopeptidase‐specific pNA substrates. Assay parameters of scale (slurry vs. direct incubations), matrix type, buffer pH, substrate concentration, assay duration and temperature, termination, and colorimetry indicated a lack of standardization and a confusion of pNA with pNP substrates despite important differences in abiotic hydrolysis and absorbance maxima. Future studies should systematically evaluate and standardize these parameters and assess the sensitivity of other amino acid‐specific aminopeptidases to carbon (C), N, and sulfur (S) cycling.
Drug‐induced vasculitis: Thiazide or the COVID‐19 vaccine, which one is guilty? A case report and literature review
Authors: Hekmat Manoochehr , Jafari Naeini Sepideh , Abbasi Zahra , Dadkhahfar Sahar
Published: June 2022

A middle‐aged woman with a history of COVID‐19 vaccine administration and valve replacement surgery was admitted with bilateral palpable purpuric lesions in the lower extremities and headache. Based on the initial diagnosis of vasculitis, corticosteroid therapy was initiated, which led to the resolution of skin lesions.
Towards equitable public sector plant breeding in the United States
Authors: Brzozowski Lauren , Hanson Solveig , Jannink Jean‐Luc , Meints Brigid , Moore Virginia , Tufan Hale , Villwock Seren
Published: June 2022

Plant breeding is central to agriculture and shifts in plant breeding practices (e.g., hybrid development) and selection goals (e.g., response to synthetic fertilizer) have catalyzed monumental and persistent changes in agricultural production systems of all scales with social, political, economic, and environmental repercussions. Although plant breeders are largely trained in the sciences of biology, genetics, and statistics, we posit an ethical imperative to examine the degree of equity with which the benefits of new research and plant cultivars are distributed. In the United States, the history of plant breeding parallels the colonial history of agriculture, which compels reflection by current plant breeders about their role in shaping our agricultural system. In this perspective essay, we examine longstanding ideas about equitable food systems through the lens of public plant breeding in the United States. We propose a framework for equitable plant breeding with respect to both its process and outcomes, and we intend for the ideas presented herein to catalyze reflection, discussions, and actions as the plant breeding community seeks greater equity in the food and seed systems our work supports.
The role of microtopography and resident species in post‐disturbance recovery of arid habitats in Hawaiʻi
Authors: Yelenik Stephanie , Rose Eli , Cordell Susan , Victoria Michelle , Kellner James R.
Published: June 2022

Habitat‐suitability indices (HSI) have been employed in restoration to identify optimal sites for planting native species. Often, HSI are based on abiotic variables and do not include biotic interactions, even though similar abiotic conditions can favor both native and nonnative species. Biotic interactions such as competition may be especially important in invader‐dominated habitats because invasive species often have fast growth rates and can exploit resources quickly. In this study, we test the utility of an HSI of microtopography derived from airborne LiDAR to predict post‐disturbance recovery and native planting success in native shrub‐dominated and nonnative, invasive grass‐dominated dryland habitats in Hawaiʻi. The HSI uses high‐resolution digital terrain models to classify sites' microtopography as high, medium, or low suitability, based on wind exposure and topographic position. We used a split‐plot before‐after‐control‐impact design to implement a disturbance experiment within native shrub (Dodonaea viscosa) and nonnative, invasive grass (Cenchrus clandestinus)‐dominated ecosystems across three microtopography categories. In contrast to previous studies using the same HSI, we found that microtopography was a poor predictor of pre‐disturbance conditions for soil nutrients, organic matter content, or foliar C:N, within both Dodonaea and Cenchrus vegetation types. In invader‐dominated Cenchrus plots, microtopography helped predict cover, but not as expected (i.e., highest cover would be in high‐suitability plots): D. viscosa had the greatest cover in low‐suitability and C. clandestinus had the greatest cover in medium‐suitability plots. Similarly, in native‐dominated Dodonaea plots, microtopography was a poor predictor of D. viscosa, C. clandestinus, and total plant cover. Although we found some evidence that microtopography helped inform post‐disturbance plant recovery of D. viscosa and total plant cover, vegetation type was a more important predictor. Important for considering the success of plantings, percent cover of D. viscosa decreased while percent cover of C. clandestinus increased within both vegetation types 20 months after disturbance. Our results are evidence that HSIs based on topographic features may prove most useful for choosing planting sites in harsh habitats or those already dominated by native species. In more productive habitats, competition from resident species may offset any benefits gained from “better” suitability sites.
Can Sphagnum removal reverse the undesired succession of rich fens under different alkalinity and fertility levels?
Authors: Singh Patrícia , Hájková Petra , Jiroušek Martin , Lizoňová Zuzana , Peterka Tomáš , Plesková Zuzana , Šímová Anna , Šmerdová Eva , Štechová Táňa , Hájek Michal
Published: June 2022

An undesired succession of rich fens leads to the formation of dense Sphagnum carpets that outcompete brown mosses and some vascular plants, resulting in biodiversity loss in fen habitats of high conservation importance. Small‐scale Sphagnum removal is a rarely implemented conservational measure, whose success may depend on soil alkalinity and fertility (i.e., nutrient availability). Therefore, characterizing the effects of pH and fertility levels would potentially allow for the development of better Sphagnum removal strategies. Two experiments were conducted across 24 rich fens of different alkalinity and fertility located in an area of ~32,000 km2 spanning from the Bohemian Massif to the Western Carpathians (Europe). We hypothesized that high alkalinity and low fertility support the restoration of rich fen vegetation after Sphagnum removal. Our study focused on four different Sphagnum groups. In Experiment 1, the treatment plots remained unfenced. In Experiment 2, the treatment plots were fenced off and target brown mosses were transplanted from the surroundings to overcome dispersal limitations. A repeated‐measures design was used, with vegetation composition recorded over a 5‐year period. High alkalinity rather than fertility facilitated species richness and the appearance of target brown mosses. High alkalinity generally hindered Sphagnum recovery, whereas high fertility supported the recurrence of S. teres and S. recurvum agg. Under high pH conditions, enhanced fertility further correlated with the spread of nonsphagnaceous generalist bryophytes of low conservation value. Despite sustaining a significant overall reduction, all Sphagnum taxa began to recover throughout the experiment, albeit less obviously in fens with S. warnstorfii. Sphagnum removal may reverse biodiversity loss and allow for the restoration of brown mosses in rich fens where Sphagnum cover had increased due to slight eutrophication, acidification, or a decrease in the water table. In alkaline and nutrient‐poor conditions (e.g., S. warnstorfii fens), the effect is evident and long lasting and the intervention may not be extensive. In fens dominated by S. teres or S. recurvum agg., repeated or large‐scale removal may be needed if high nutrient availability (potassium, phosphorus) or low alkalinity supports Sphagnum recolonization. Treatment plots with S. subgenus Sphagnum exhibited the least promising brown‐moss restoration prospects.
Mixture Toxicity of Herbicides with Dissimilar Modes of Action to Myriophyllum spicatum
Authors: Fusilero Abegail , De Rop Jasmine , Spanoghe Pieter , Arts Gertie H. P. , De Schamphelaere Karel A. C.
Published: June 2022

Considering the vital role of rooted macrophytes in the aquatic ecosystem, validating assumptions on the interactive effects of herbicides with different modes of action at an environmentally relevant mixture ratio is necessary. We investigated the effects of diflufenican (a carotenoid biosynthesis inhibitor) and iodosulfuron-methyl-sodium (IMS; an acetolactate synthase inhibitor) in a 14-day growth inhibition experiment with Myriophyllum spicatum, wherein single compounds and their combination were tested in parallel (n = 84). The assessment was done using three different methods: significance testing, model deviation ratio (MDR), and mixture interaction factor (MIF). Interactions relative to both concentration addition and independent action were assessed via significance testing. This revealed that diflufenican and IMS acted antagonistically relative to both models for fresh weight and total shoot length (p < 0.05) and that there was slight synergism for the number of side shoots (p < 0.001) relative to concentration addition. The MDR and MIF can only assess interactions relative to the concentration addition model. According to MDR, the mixture appeared to show no interaction (neither antagonistic nor synergistic), whereas the MIF method revealed that the compounds acted antagonistically for fresh weight and that there was a slight synergism for total shoot length and number of side shoots. We conclude that inferences about mixture toxicity interactions are method- and endpoint-dependent, which can have implications for regulatory mixtures assessment. Environ Toxicol Chem 2022;41:2209–2220. © 2022 SETAC
Key state‐level policy elements governing pharmacist collaborative practice
Authors:   American College of Clinical Pharmacy
Published: June 2022

The American College of Clinical Pharmacy previously published a white paper in 2015, “Collaborative Drug Therapy Management and Comprehensive Medication Management,” as well as position statements on collaborative drug therapy management (CDTM) in 1997 and 2003. Although significant federal and state legislation addressing collaborative practice has evolved and expanded throughout the United States since then, variability in state‐level policy remains a barrier for effective collaborative practice. Collaborative practice facilitates the delivery of comprehensive medication management by clinical pharmacists and enhances team‐based care. State governments are the primary entities that determine the scope of practice for health professionals. As such, state‐level policy plays a crucial role in enabling or impeding the implementation of advanced pharmacist services and effective CDTM. Almost all states currently enable pharmacist prescriptive authority in some form. In 2017, the National Alliance of State Pharmacy Associations and the National Association of Boards of Pharmacy issued joint recommendations outlining model elements of state policies for statewide protocol authority and pharmacist prescribing.
Persistence phenomena of classical solutions to a fractional Keller–Segel model with time‐space dependent logistic source
Authors: Zhang Weiyi , Liu Zuhan , Zhou Ling
Published: June 2022

In this paper, we consider the following fractional parabolic‐elliptic Keller–Segel system with time‐space dependent logistic source on the whole space

where
and
are positive constants and the functions
and
are positive and bounded. When the order of fractional diffusion
and the functions
and
satisfy some conditions, we first prove the local existence and uniqueness of nonnegative classical solutions
with
for every
and every nonnegative bounded and uniformly continuous initial function
. Next, under some parameter conditions, we prove the global existence and boundedness of classical solutions
for given initial function
. Finally, we obtain the pointwise persistence phenomena of solutions; that is, for any strictly positive initial function
, there are
such that

and obtain the uniform persistence phenomena of solutions; that is, there are
such that for any strictly positive initial function
there exists
such that

In summary, these results are extension to the case of fractional parabolic‐elliptic Keller–Segel system.
Thermophysical properties of hybrid silica phenolic ablative composite: Theoretical and experimental analysis
Authors: Jithin A. J. Aravind , Panigrahi Sushanta K. , P. Sasikumar , K. Rao Shreedhar , Ali T. K. Shabeeb , G. Krishnakumar
Published: June 2022

Silica phenolic ablative composites are used in many high‐temperature applications like rocket/missile solid motor nozzles, space re‐entry vehicles, and so forth. As ablative composite with lower thermal conductivity and density can save considerable cost, a hybrid silica phenolic ablative composite was developed by establishing a novel processing methodology using chopped silica fiber, phenolic resin, and hollow glass microsphere. The thermophysical properties of the developed hybrid composite are analyzed and established the scientific know‐how. The developed composites, with 36% lower density, displayed 50% lower thermal conductivity and 50% lower thermal diffusivity than standard silica phenolic composite. Since a proper thermal conductivity model for a three‐component composite with matrix, fiber, and hollow glass microsphere is not available, the most suitable model for the developed composite is established.
Additive manufacturing of jute fiber reinforced polymer composites: A concise review of material forms and methods
Authors: Devarajan Balaji , LakshmiNarasimhan Rajeshkumar , Venkateswaran Bhuvaneswari , Mavinkere Rangappa Sanjay , Siengchin Suchart
Published: June 2022

Additive manufacturing is accelerating in hypersonic speed, which touched upon almost all the nook and corners of the manufacturing sector. The present stage wherein a 3D printer is capable of printing queer hybrid materials was not imagined through conventional manufacturing albeit it is meager existence in a few instances. Its expendable arms stretch to the maximum level that is even clearly addressed in Industry 4.0 too, by making at least a printer in a company for printing specific customized materials. The dream of printing composite material was been a long‐term goal for researchers worldwide. This article primarily focuses on this niche area of printing natural fiber composite materials that too specifically jute fiber‐reinforced composites. Very few pieces of literature are available on additive manufacturing of specific natural fibers. As the technique for printing natural fiber‐reinforced composites is still under evolution, this study will be more interesting as it consolidates the facts and figures involved in 3D of jute fiber reinforced composites alone. Different forms of jute fibers used by the researchers include weaved jute, jute as continuous fiber, filament along with jute, jute fiber as reinforcement, jute used as rope as well as jute fiber as cement matrix and all these forms have been addressed in this review.
A Molten‐Salt Method to Synthesize Ultrahigh‐Nickel Single‐Crystalline LiNi0.92Co0.06Mn0.02O2 with Superior Electrochemical Performance as Cathode Material for Lithium‐Ion Batteries
Authors: Lv Fei , Zhang Yimin , Wu Mengtao , Gu Yuzong
Published: June 2022

Ni‐rich layered oxides have been intensively considered as promising cathode materials for next‐generation Li‐ion batteries. Nevertheless, the performance degradation caused by intergranular cracks and electrode/electrolyte interface parasitic reactions restricts their further application. Compared with secondary particles, single‐crystal (SC) materials have better mechanical integrity and cycling stability. However, the preparation of ultrahigh‐nickel layered SC cathode still remains a serious challenge. Herein, a novel LiOH‐LiNO3‐H3BO3 molten‐salt method is proposed to synthesize SC LiNi0.92Co0.06Mn0.02O2 with considerable crystallinity and uniformity. The critical impacts of calcination temperature and boric acid on the microstructure and electrochemical property of Ni‐rich layered oxides are systematically investigated. The results show that the crystal growth is promoted and the stability of crystal structure is improved by this synthesis method. In particular, the optimal electrode demonstrates a superior initial discharge capacity of 214.8 mAh g–1 with a high capacity retention of 86.3% over 300 cycles as tested by pouch‐type full cells at 45 ºC. This work not only prepares an ultrahigh‐nickel layered CS cathode with superior electrochemical performances, but also provides a feasible method for the synthesis of other CS layered cathode materials.
Who creates international marketing agility? Diasporic agility guiding new market entry processes in emerging contexts
Authors: Elo Maria , Silva Susana
Published: June 2022

International marketing agility is a crucial dynamic capability in international business. The purpose of this article is to examine who creates it and how exporters and partners leverage diasporic agility. We employ case study research on two diaspora entrepreneurs acting as ambidextrous strategic channel partners and playing a central role in guiding the exporter to new markets. In both cases, the role of the diaspora entrepreneurs as channel partners was decisive in providing multistage agility for the exporter while employing their specific market drive and understanding as a source of competitive advantage. While the exporters concentrated on their core business, the partners sensed, seized, and reconfigured resources to enable market entry and growth under culturally and politico‐economically demanding conditions. The diasporic understanding of the markets was a unique form of this agility and fundamental for the right strategies and an exporter's international marketing. Diaspora channel partners facilitated entry and lowered the cost of international marketing by providing advanced and more locally legitimate knowledge, fostering ambidexterity. We contribute to the conceptualization of the role of diaspora as an international marketing agility actor.
Final global leadership development program (GLDP) design: Where do we go from here? Global evidence from Europe, the US, and Brazil
Authors: Hruby Jörg , Almeida Paulo , Hoeft Christina
Published: June 2022

The development of high potentials within global companies remains a challenge in leadership development in the face of increasingly dynamic environments. Despite this, we know surprisingly little about the practices business schools and corporations follow when it comes to Global Leadership Development Programs (GLDP). In this article, we derive critical success factors of the components of a GLDP leveraging evidence of 90 conducted panel interviews with global human resources experts and qualitative analysis of 33 GLDPs, 20 high‐level executive storytelling about competences and practical key elements leading successful and results‐driven change in their global companies, and 12 interviews with executive education directors. We examine within a grounded theory approach two overall under‐explored questions. What is a successful GLDP? Moreover, how to design it? What are the critical success factors in designing a GLDP? We derive a checklist to help implement future GLDPs within their global organizations. Our findings and discussion outline future research recommendations and provide advice for GLDP designers within Executive Education or HR Development contexts.
(Re)Animating Children's Aesthetic Experiences With/Through Literature: Critically Curating Picturebooks as Sociopolitical Art
Authors: Zapata Angie
Published: June 2022

In this column, I evoke a long‐standing call for children's aesthetic experiences with literature and do so by (re)claiming picturebooks as sociopolitical art that demands critical curation and instruction in the classroom.
Antiviral nanopharmaceuticals: Engineered surface interactions and virus‐selective activity
Authors: Kolanthai Elayaraja , Neal Craig J. , Kumar Udit , Fu Yifei , Seal Sudipta
Published: June 2022

The COVID‐19 pandemic has inspired large research investments from the global scientific community in the study of viral properties and antiviral technologies (e.g., self‐cleaning surfaces, virucides, antiviral drugs, and vaccines). Emerging viruses are a constant threat due to the substantial variation in viral structures, limiting the potential for expanded broad‐spectrum antiviral agent development, and the complexity of targeting multiple and diverse viral species with unique characteristics involving their virulence. Multiple, more infectious variants of SARS‐CoV2 (e.g., Delta, Omicron) have already appeared, necessitating research into versatile, robust control strategies in response to the looming threat of future viruses. Nanotechnology and nanomaterials have played a vital role in addressing current viral threats, from mRNA‐based vaccines to nanoparticle‐based drugs and nanotechnology enhanced disinfection methods. Rapid progress in the field has prompted a review of the current literature primarily focused on nanotechnology‐based virucides and antivirals. In this review, a brief description of antiviral drugs is provided first as background with most of the discussion focused on key design considerations for high‐efficacy antiviral nanomaterials (e.g., nanopharmaceuticals) as determined from published studies as well as related modes of biological activity. Insights into potential future research directions are also provided with a section devoted specifically to the SARS‐CoV2 virus.

This article is categorized under:

Toxicology and Regulatory Issues in Nanomediciney > Toxicology of Nanomaterials

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease
Dynamical consequences of 1-form symmetries and the exceptional Argyres-Douglas theories
Authors: Carta Federico , Giacomelli Simone , Mekareeya Noppadol , Mininno Alessandro
Published: June 2022

Abstract

Higher-form symmetries have proved useful in constraining the dynamics of a number of quantum field theories. In the context of the Argyres-Douglas (AD) theories of the (G, G′) type, we find that the 1-form symmetries are invariant under the Higgs branch flow, and that they are captured by the non-Higgsable sector at a generic point on the Higgs branch of the AD theory in question. As a consequence, dimensional reduction of an AD theory with a non-trivial 1-form symmetry to 3d leads to a free sector. We utilize these observations, along with other results, to propose systematically the mirror theories for the AD theories of the (An, Em) type. As a by-product of these findings, we discover many important results: the Flip-Flip duality for all T[G] theories with simply-laced group G, including the exceptional ones; the class $$ \mathcal{S} $$
S
descriptions of exceptional affine Dynkin diagram such that all gauge groups are special unitary; the universality of the mirror theories for $$ {D}_{h_G^{\vee }} $$

D

h
G
∨

(G) with $$ {h}_G^{\vee } $$

h
G
∨

the dual Coxeter number of G; and the triviality of the 2-group structure in the (An, Em) theories.
Non-factorisable contribution to t-channel single-top production
Authors: Brønnum-Hansen Christian , Melnikov Kirill , Quarroz Jérémie , Signorile-Signorile Chiara , Wang Chen-Yu
Published: June 2022

Abstract

We compute the non-factorisable $$ \mathcal{O} $$
O
($$ {\alpha}_s^2 $$

α
s
2

) corrections to t-channel single-top quark production at the LHC. These peculiar corrections arise because of interactions between the heavy- and the light-quark lines and appear for the very first time at next-to-next-to-leading order in perturbative QCD. We find that the non-factorisable corrections change the single-top production cross section and the relevant kinematic distributions in this process by about half a percent.
Effectiveness of Pharmacotherapy for Depression after Adult Traumatic Brain Injury: an Umbrella Review
Authors: Hicks Amelia J. , Clay Fiona J. , James Amelia C. , Hopwood Malcolm , Ponsford Jennie L.
Published: June 2022

Symptoms of depression are common following traumatic brain injury (TBI), impacting survivors’ ability to return to work, participate in leisure activities, and placing strain on relationships. Depression symptoms post TBI are often managed with pharmacotherapy, however, there is little research evidence to guide clinical practice. There have been a number of recent systematic reviews examining pharmacotherapy for post TBI depression. The aim of this umbrella review was to synthesize systematic reviews and meta-analyses of the effectiveness of pharmacotherapy for the management of post TBI depression in adults. Eligible reviews examined any pharmacotherapy against any comparators, for the treatment of depression in adults who had sustained TBI. Seven databases were searched, with additional searching of online journals, Research Gate, Google Scholar and the TRIP Medical Database to identify published and unpublished systematic reviews and meta-analyses in English up to May 2020. A systematic review of primary studies available between March 2018 and May 2020 was also conducted. Evidence quality was assessed using Joanna Briggs Institute Critical Appraisal Instruments. The results are presented as a narrative synthesis. Twenty-two systematic reviews were identified, of which ten reviews contained a meta-analysis. No new primary studies were identified in the systematic review. There was insufficient high quality and methodologically rigorous evidence to recommend prescribing any specific drug or drug class for post TBI depression. The findings do show, however, that depression post TBI is responsive to pharmacotherapy in at least some individuals. Recommendations for primary studies, systematic reviews and advice for prescribers is provided. Review Registration PROSPERO (CRD42020184915).
Pilot Study: PARP1 Imaging in Advanced Prostate Cancer
Authors: Dehdashti Farrokh , Reimers Melissa A. , Shoghi Kooresh I. , Chen Delphine L. , Luo Jingqin , Rogers Buck , Pachynski Russell K. , Sreekumar Sreeja , Weimholt Cody , Zhou Dong
Published: June 2022

Purpose

PARP inhibitor (PARPi) therapy is approved for patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) genomic aberrations. However, only a fraction of patients with BRCA1/2 mutations respond to PARPi therapy. In this pilot study, we assess PARP-1 expression in prostate cancer patients with and without HRR genomic alternations using a novel PARP-based imaging agent.

Procedures

Nine advanced prostate cancer patients were studied with PET/CT and [18F]FluorThanatrace (FTT), an analogue of the PARPi rucaparib. Images were analyzed using maximum standardized uptake values (SUVmax). PARP expression was assessed by immunohistochemistry (IHC) when feasible (n = 4).

Results

We found great variability in FTT uptake (SUVmax range: 2.3–15.4). Patients with HRR mutations had a significantly higher SUVmax (p = 0.0379) than patients with non-HRR mutations although there was an overlap in FTT uptake between groups. Three patients without HRR and one with HRR mutations had similarly high PARP1 IHC expression.

Conclusions

FTT-PET/CT may serve as an alternate biomarker for PARP1 expression and a potential method for PARPi treatment selection.
Rethinking climate migration in sub-Saharan Africa from the perspective of tripartite drivers of climate change
Authors: Ibrahim Bachar , Mensah Henry
Published: June 2022

There is limited attention on climate change (CC) and human migration among scholars and policymakers. Meanwhile, natural disasters are projected to induce migration in the coming years which will affect millions of people in sub-Saharan Africa (SSA). In this review, we contribute to climate migration literature by highlighting three important factors (i.e. floods, droughts, and sea-level rise) that predispose migrants in SSA to migrate. The review suggests that the environmental impact of CC in SSA cannot be overlooked. For example, the review discovered that the impact of flooding has intensified, and its impact on agriculture will affect rural–urban migration, forcing farmers to look for alternative job opportunities. Moreover, due to the lack of rainfall to support agricultural activities, the option of migrating away from agriculture and settling in urban areas becomes a possible coping strategy. Rising sea level will adversely affect many, due to a lack of adaptive capacity and emergency preparedness. This should concern policymakers because the major trend in migration, whether climate-related or not, is a movement from rural to urban areas which poses significant challenges to urban sustainability and climate resilience. Given the impact of floods, droughts, and sea-level rise in SSA, we propose the promotion of adaptive capacity through the encouragement of climate insurance programme which is limited in SSA, alternative livelihood opportunity programmes, and providing financial resources for climate adaptation initiatives.