bluuebunny/crossref_metadata_2025 huggingface dataset:
Dark matter scattering in astrophysical media: collective effects
Authors: DeRocco William , Galanis Marios , Lasenby Robert
Published: May 2022

It is well-known that stars have the potential
to be excellent dark matter detectors.
Infalling dark matter that scatters within stars
could lead to a range of observational
signatures, including stellar heating, black hole formation,
and modified heat transport.
To make robust predictions for such
phenomena, it is necessary to calculate the
scattering rate for dark matter inside the star.
As we show in this paper, for small enough momentum
transfers, this requires taking into account 
collective effects within the dense stellar medium.
These effects have been neglected in many previous treatments;
we demonstrate how to incorporate them systematically, and show
that they can parametrically enhance or suppress
dark matter scattering rates depending on how dark matter
couples to the Standard Model.
We show that, as a result, collective effects can significantly
modify the potential discovery or exclusion reach
for observations of compact objects such as white dwarfs and neutron stars.
While the effects are more pronounced for dark matter coupling
through a light mediator,
we show that even for dark matter coupling via a heavy mediator,
scattering rates can differ by orders of magnitude from
their naive values for dark matter masses ≲ 100 MeV.
We also illustrate how collective effects can be important
for dark matter scattering in more dilute media,
such as the Solar core.
Our results demonstrate the need to systematically incorporate
collective effects in a wide range of astroparticle
contexts; to facilitate this, we provide expressions
for in-medium self-energies for a variety of
different media, which are applicable to many other
processes of interest (such as particle production).
Two-mode Schrödinger-cat states with nonlinear optomechanics: generation and verification of non-Gaussian mechanical entanglement
Authors: Kanari-Naish Lydia A , Clarke Jack , Qvarfort Sofia , Vanner Michael R
Published: May 2022

Cavity quantum optomechanics has emerged as a new platform for quantum science and technology with applications ranging from quantum-information processing to tests of the foundations of physics. Of crucial importance for optomechanics is the generation and verification of non-Gaussian states of motion and a key outstanding challenge is the observation of a canonical two-mode Schrödinger-cat state in the displacement of two mechanical oscillators. In this work, we introduce a pulsed approach that utilizes the nonlinearity of the radiation–pressure interaction combined with photon-counting measurements to generate this entangled non-Gaussian mechanical state, and, importantly, describe a protocol using subsequent pulsed interactions to verify the non-Gaussian entanglement generated. Our pulsed verification protocol allows quadrature moments of the two mechanical oscillators to be measured up to any finite order providing a toolset for experimental characterisation of bipartite mechanical quantum states and allowing a broad range of inseparability criteria to be evaluated. Key experimental factors, such as optical loss and open-system dynamics, are carefully analyzed and we show that the scheme is feasible with only minor improvements to current experiments that operate outside the resolved-sideband regime. Our scheme provides a new avenue for quantum experiments with entangled mechanical oscillators and offers significant potential for further research and development that utilizes such non-Gaussian states for quantum-information and sensing applications, and for studying the quantum-to-classical transition.
A transferable force-field for alkali metal nitrates
Authors: Fantauzzo V , Yeandel S R , Freeman C L , Harding J H
Published: May 2022

We present a new rigid-ion force-field for the alkali metal nitrates that is suitable for simulating solution chemistry, crystallisation and polymorphism. We show that it gives a good representation of the crystal structures, lattice energies, elastic and dielectric properties of these compounds over a wide range of temperatures. Since all the alkali metal nitrates are fitted together using a common model for the nitrate anion, the force-field is also suitable for simulating solid solutions. We use the popular Joung and Cheatham model for the interactions of the alkali metal cations with water and obtain the interaction of the nitrate ion with water by fitting to a hydrate.
Purification effect of aquatic plant communities in constructed wetland park: a comparative experiment of Tianhe wetland park in China
Authors: Xiang Luoning , Zhang Hui , Chen Zhuojian , Chen Chumin , Chen Ping , Sang Kun , Hua Guodong
Published: May 2022

Constructed wetland parks in urban areas can offer the potential for integrating water conservation and purification. Compared with other treatments, filtering out pollutants by wetland plants is one of the methods used widely for its fast processing time and limited costs. And species allocation plays an important role in the purification process. However, some problems are still waiting for further discussions, such as the purification efficiency in winter due to plant growth rate, etc. Against this background, this paper introduced the Tianhe Wetland Park in China as the site for a comparative experiment, to propose a methodology for testing the purification effect under different plant communities. Through site investigation and lab experiments with water monitoring, the process of water purification by wetland was simulated in the park. After a period of observation and measurement, seven water indexes (pH value, dissolved oxygen, total phosphorus, total nitrogen, ammonia nitrogen, chemical oxygen demand, and turbidity) were selected for the evaluation of water quality to compare the different absorption efficiency by different communities. As a result, the research showed that a configuration of plant community using arboreal, emergent, and submerged plants can carry out a good purification effect during the winter, including Callistemon viminalis, Bischofia javanica, Canna indica, Juncus effusus, Vallisneria natans, and Hydrilla verticillata var. rosburghii. The removal rate of DO, TU, COD, TP, and TN by the designed community can reach 43%, 65%, 45%, 51%, and 62% in sampling sites. Finally, based on the research results, further suggestions for the development of wetlands were proposed to improve park management in the study area.
Flexural and dynamic response of carbon/epoxy laminates with graphene nanofillers and Al6061 alloy
Authors: Shebaz Ahmed J P , Meenakshisundaram Omkumar
Published: May 2022

The mechanical and vibrational isolation properties of reinforced carbon fibre composites, such as carbon fibre [0]7s/epoxy, carbon fibre [0]6s/Graphene nanopowder/epoxy, and carbon fibre [0]4s/epoxy/Al 6061, are investigated in this research. Ultrasonic stirring was employed in a carbon fiber/graphene-nano powder laminate to reinforce 0.5 weight percent graphene nanoparticles with the resin. The effect of nano-fillers and metal laminate in the carbon fiber composite specimen was analysed by considering glass transition temperature, flexural modulus, and natural frequency. The results show that the Carbon Fiber Reinforced Polymer (CFRP) with graphene shows a 16.9% and 57.5% increment in flexural strength compared to CFRP and CFRP with Al6061 alloy. In contrast, in the DMA test, the glass transition temperature and other parameters show the least difference, whereas the loss modulus is 34.3% and 67% high for CFRP compared to CFRP/graphene and CFRP/Al6061 samples. Furthermore, using graphene nanopowder and aluminium plates reduces the carbon epoxy laminate’s inherent frequency.
Meandering through the virtual MIST
Authors: Wiggs Josh , Hodnett Rosie , Walach Maria-Theresia , Walton Samuel
Published: May 2022

Josh Wiggs, Rosie Hodnett, Maria-Theresia Walach and Samuel Walton round up the talks and discussion topics presented at the annual – and again virtual – MIST meeting in November 2021
Joint registration of multiple point clouds for fast particle fusion in localization microscopy
Authors: Wang Wenxiu , Heydarian Hamidreza , Huijben Teun A P M , Stallinga Sjoerd , Rieger Bernd
Published: May 2022

We present a fast particle fusion method for particles imaged with single-molecule localization microscopy. The state-of-the-art approach based on all-to-all registration has proven to work well but its computational cost scales unfavorably with the number of particles N, namely as N2. Our method overcomes this problem and achieves a linear scaling of computational cost with N by making use of the Joint Registration of Multiple Point Clouds (JRMPC) method. Straightforward application of JRMPC fails as mostly locally optimal solutions are found. These usually contain several overlapping clusters that each consist of well-aligned particles, but that have different poses. We solve this issue by repeated runs of JRMPC for different initial conditions, followed by a classification step to identify the clusters, and a connection step to link the different clusters obtained for different initializations. In this way a single well-aligned structure is obtained containing the majority of the particles.

Results

We achieve reconstructions of experimental DNA-origami datasets consisting of close to 400 particles within only 10 min on a CPU, with an image resolution of 3.2 nm. In addition, we show artifact-free reconstructions of symmetric structures without making any use of the symmetry. We also demonstrate that the method works well for poor data with a low density of labeling and for 3D data.

Availability and implementation

The code is available for download from https://github.com/wexw/Joint-Registration-of-Multiple-Point-Clouds-for-Fast-Particle-Fusion-in-Localization-Microscopy.

Supplementary information

Supplementary data are available at Bioinformatics online.
A multisite evaluation of antifungal use in critical care: implications for antifungal stewardship
Authors: Logan C , Hemsley C , Fife A , Edgeworth J , Mazzella A , Wade P , Goodman A , Hopkins P , Wyncoll D , Ball J , Planche T , Schelenz S , Bicanic T
Published: May 2022

Background

ICUs are settings of high antifungal consumption. There are few data on prescribing practices in ICUs to guide antifungal stewardship implementation in this setting.

Methods

An antifungal therapy (AFT) service evaluation (15 May–19 November 2019) across ICUs at three London hospitals, evaluating consumption, prescribing rationale, post-prescription review, de-escalation and final invasive fungal infection (IFI) diagnostic classification.

Results

Overall, 6.4% of ICU admissions (305/4781) received AFT, accounting for 11.41 days of therapy/100 occupied bed days (DOT/100 OBD). The dominant prescribing mode was empirical (41% of consumption), followed by targeted (22%), prophylaxis (18%), pre-emptive (12%) and non-invasive (7%). Echinocandins were the most commonly prescribed drug class (4.59 DOT/100 OBD). In total, 217 patients received AFT for suspected or confirmed IFI; 12%, 10% and 23% were classified as possible, probable or proven IFI, respectively. Hence, in 55%, IFI was unlikely. Proven IFI (n = 50) was mostly invasive candidiasis (92%), of which 48% had been initiated on AFT empirically before yeast identification. Where on-site (1 → 3)-β-d-glucan (BDG) testing was available (1 day turnaround), in those with suspected but unproven invasive candidiasis, median (IQR) AFT duration was 10 (7–15) days with a positive BDG (≥80 pg/mL) versus 8 (5–9) days with a negative BDG (<80 pg/mL). Post-prescription review occurred in 79% of prescribing episodes (median time to review 1 [0–3] day). Where suspected IFI was not confirmed, 38% episodes were stopped and 4% de-escalated within 5 days.

Conclusions

Achieving a better balance between promptly treating IFI patients and avoiding inappropriate antifungal prescribing in the ICU requires timely post-prescription review by specialist multidisciplinary teams and improved, evidence-based-risk prescribing strategies incorporating rapid diagnostics to guide AFT start and stop decisions.
The new Swiss trust: Is it a trust? Practical considerations
Authors: Noseda Filippo
Published: May 2022

In a world awash with academic articles on the compatibility of trusts with civil law systems, the author considers some practical implications of the terminology used by the Swiss legislator in its draft Bill on new trust provisions to be inserted in the Swiss Code of Obligations. This article draws from the author's experience as an English solicitor with a Swiss background.
Informing women about the risks of exposing babies to tobacco smoke: outreach and education efforts using Facebook “boost posts”
Authors: Miller Carrie A , Jung Kim Sunny , Schwartz-Bloom Rochelle D , Bloom Paul N , Murphy Susan K , Fuemmeler Bernard F
Published: May 2022

Maternal smoking is associated with a host of negative health outcomes, including an increased risk of children developing attention-deficit/hyperactivity disorder (ADHD). This study evaluated the efficacy of health messages disseminated through Facebook Ads focused on reducing tobacco smoke exposure during pregnancy. Two message versions were promoted via post advertisements on Facebook—a static infographic and a video containing an animated version of the infographic. The reach of and engagement with each message version was evaluated. Comments made to the posts were assessed using content analysis. The infographic reached approximately 60,000 people and the video reached about 16,000 people. The average costs were $10.00 and $40.00 per 1,000 people reached for the infographic- and video-based posts, respectively. While there was no engagement with the video, the infographic was liked (n = 157), given alternative likes (n = 59), shared (n = 171 to 341), and commented on (n = 221). About one-quarter of comments contained a personal narrative and mentions of health history related to ADHD and/or smoking. Comments were more often negative (than positive) (16.6% vs 3.9%) and expressed skepticism more often than message acceptance (21.5% vs 12.2%). Facebook users were more responsive to the infographic (compared to the video) and static posts were a preferred channel (i.e., higher engagement at a lower cost) to disseminate messages when using the boost post feature on Facebook for health education. Our review of the comments provided insights into message acceptance and guidance for future social media-based health message campaigns. However, it is not known whether and if so, how, these findings on message exposure would correlate with behavioral intentions or changes in behavior, such as intentions to quit smoking or smoking cessation.
Nanoparticles are linked to polar lipids in xylem sap of temperate angiosperm species
Authors: Guan Xinyi , Schenk H Jochen , Roth Mary R , Welti Ruth , Werner Julia , Kaack Lucian , Trabi Christophe L , Jansen Steven
Published: May 2022

In previous research, xylem sap of angiosperms has been found to include low concentrations of nanoparticles and polar lipids. A major goal of this study was to test predictions arising from the hypothesis that the nanoparticles consist largely of polar lipids from the original cell content of vessel elements. These predictions included that polar lipid and nanoparticle concentrations would be correlated, that they both do not pass through pit membranes and that they do not vary seasonally because they originate from living vessel element cells. We collected xylem sap of six temperate angiosperm species over the whole year to consider seasonal variation. Concentrations of nanoparticles and lipids in xylem sap and contamination control samples were measured with a NanoSight device and mass spectrometry. We found that the concentration of nanoparticles and polar lipids was (i) diluted when an increasing amount of sap was extracted, (ii) significantly correlated to each other for three species, (iii) affected by vessel anatomy, (iv) very low and largely different in chemical composition from contamination controls and (v) hardly variable among seasons. Moreover, there was a minor freezing–thawing effect with respect to nanoparticle amount and size. Xylem sap lipids included polar galactolipids and phospholipids in all species and neutral triacylglycerols in two species. These findings support the predictions and, by implication, the underlying hypothesis that nanoparticles in xylem sap consist of polar lipids from the original cell content of living vessel element cells. Further research is needed to examine the formation and stability of nanoparticles concerning lipid composition and multiphase interactions among gas, liquid and solid phases in xylem conduits of living plants.
Is Surgery Needed for Diplopia after Blowout Fractures? A Clarified Algorithm to Assist Decision-making
Authors: Lin Cen-Hung , Lee Su-Shin , Wen Lin I , Su Wan-Ju
Published: May 2022

Background:

Diplopia is a common symptom after blowout fractures, with an incidence of 43.6%–83%. Although there is some consensus toward surgical correction, diplopia is not always resolved by surgery. Thus, there is a clinical dilemma for surgeons with regard to performing surgery at a specific time. This review aimed to create an algorithm to support accurate and effective decision-making.

Methods:

We reviewed articles published on PubMed during 2013–2020 regarding orbital fractures. Articles discussing surgical treatment for blowout fractures and diplopia were included. Five reviews, six prospective cohort studies, and 33 retrospective studies were identified. After reviewing and summarizing these articles, a step-by-step algorithm was created.

Results:

Most authors advise immediate surgery when a patient presents with either a positive oculocardiac reflex or a “trapdoor” fracture. Early surgical correction is recommended in children to prevent profound muscle damage. In other scenarios, most authors recommend performing surgery within 2 weeks. The algorithm begins with the aspect of motility, including muscle entrapment assessed by computed tomography or limited movement of the extraocular muscle. When there is no abnormality in motility, the algorithm continues to the aspect of position. Generally, an orbital floor defect of more than 50% or 2 cm2 or an enophthalmos of more than 2 mm is indicated for surgery. However, diplopia may also gradually resolve after improvement of periorbital edema or swelling.

Conclusion:

We proposed a step-by-step approach to help surgeons make effective decisions concerning surgical correction for patients suffering from blowout fractures with diplopia at different time points.
Osteoarthritis in Athletes Versus Nonathletes: A Systematic Review
Authors: Migliorini Filippo , Marsilio Emanuela , Torsiello Ernesto , Pintore Andrea , Oliva Francesco , Maffulli Nicola
Published: May 2022

Introduction:

Joint overload and sport-related injuries may accelerate the development of osteoarthritis (OA). A systematic review of the literature was performed to establish the risk of athletes to develop premature OA compared with nonathletes.

Materials and Methods:

This systematic review was conducted according to the PRISMA guidelines. PubMed, Google scholar, Embase, and Web of Science databases were accessed in June 2021. All the published clinical studies investigating OA onset in athletes versus nonathletes were considered. Studies reporting data on secondary and/or post-traumatic OA were excluded.

Results:

Data from 32 articles (20,288 patients) were retrieved. The mean age was 67.8±10.0 years and the mean body mass index was 25.0±2.5 kg/m2. 74% (6859 patients) of the athletes suffered from premature OA. Of them, 21% were active in soccer, 11% in handball, 11% in ice-hockey, 3% in football, and 0.3% in rugby. 26% of the athletes reported no significant differences in OA progression compared with healthy controls. Of these athletes, 47% were runners, 5% dancers, and 1% triathletes.

Conclusion:

Certain sports, such as soccer, handball, ice-hockey, and rugby are more likely to be associated with premature knee and hip OA. Conversely, runners and ballet dancers do not evidence significant increase in OA. Moderate and recreational exposure to aerobic sports does not accelerate the development of OA.
The Impact of COVID-19 Pandemic on Screening Programs for Cervical Cancer Prevention Across Europe
Authors: Carcopino Xavier , Cruickshank Maggie , Leeson Simon , Redman Charles , Nieminen Pekka
Published: May 2022

Objective

The aim of the study was to estimate the impact of COVID-19 pandemic on the practice of cervical cancer screening in European countries.

Materials and Methods

A 3 rounds e-survey was conducted among the 31 European Federation for Colposcopy member countries during 2020. Each representative was asked to answer to each questionnaire for their own country. Questionnaires were not anonymous. The first questionnaire was sent in April 2020 and second and third in June and December 2020, respectively.

Results

Twenty five of the 31 European countries solicited responded. A total of 19 countries (70.4%) reported that screening for cervical cancer was suspended at least once during the 3 rounds of questionnaires. In addition, 11 countries reported stopping colposcopy and treatments for cervical precancerous lesions at least once during the 3 rounds of questionnaires. These situations evolved with time, with the highest rate of countries recommending suspension of screening, colposcopy, and treatments during the second round of the survey. At round 3, no country recommended screening, colposcopy, and treatment, and 12 countries (57.5%) reported normal screening was fully implemented.

Conclusions

Our results suggest massive disruption in cervical cancer screening programs across Europe resulting from COVID-19 pandemic. Increase in the incidence of cervical cancer is to be expected.
Scientific View of the Global Literature on Medical Error Reporting and Reporting Systems From 1977 to 2021: A Bibliometric Analysis
Authors: Ünal Aysun , Seren Intepeler Şeyda
Published: May 2022

Background

Error reporting is vital for the prevention of medical errors. Despite the importance of error reporting, underreporting of medical errors is a common reality in many countries. Therefore, barriers to error reporting and reporting systems are a constantly evolving field of research. For this reason, studies on medical error reporting and reporting systems should be evaluated multidimensionally.

Aim

The aim of this study is to evaluate the global research on medical error reporting and reporting systems through bibliometric analysis to obtain a structured macroscopic overview of the features and developments.

Methods

A bibliometric analysis of 1464 publications from 1970 to 2021 was performed to map the literature of medical error reporting and assess the structure of the scientific community.

Results

After 2000, the number of publications increased annually until a maximum of 2020 was reached. The International Journal for Quality in Health Care and the Journal of Patient Safety have been the most productive journals when it comes to publishing on the subject. Trend topics of keyword plus have changed over time. The United States (1399), England (580), and Australia (478) are the 3 nations with the highest number of publications. On the other hand, it is seen that the subject has yet to be discussed in a few developing or underdeveloped countries.

Conclusions

This bibliometric analysis shows that the number of publications and authors and cross-country cooperation are low regarding error reporting. The low number of publications and the lack of cooperation, especially in developing countries, reveal the importance of global cooperation.
Continuing invariant solutions towards the turbulent flow
Authors: Parente E. , Farano M. , Robinet J.-Ch. , De Palma P. , Cherubini S.
Published: May 2022

A new mathematical framework is proposed for characterizing the coherent motion of fluctuations around a mean turbulent channel flow. We search for statistically invariant coherent solutions of the unsteady Reynolds-averaged Navier–Stokes equations written in a perturbative form with respect to the turbulent mean flow, using a suitable approximation of the Reynolds stress tensor. This is achieved by setting up a continuation procedure of known solutions of the perturbative Navier–Stokes equations, based on the continuous increase of the turbulent eddy viscosity towards its turbulent value. The recovered solutions, being sustained only in the presence of the Reynolds stress tensor, are representative of the statistically coherent motion of turbulent flows. For small friction Reynolds number and/or domain size, the statistically invariant motion is almost identical to the corresponding invariant solution of the Navier–Stokes equations. Whereas, for sufficiently large friction number and/or domain size, it considerably departs from the starting invariant solution of the Navier–Stokes equations, presenting spatial structures, main wavelengths and scaling very close to those characterizing both large- and small-scale motion of turbulent channel flows.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.
Self-regularization in turbulence from the Kolmogorov 4/5-law and alignment
Authors: Drivas Theodore D.
Published: May 2022

A defining feature of three-dimensional hydrodynamic turbulence is that the rate of energy dissipation is bounded away from zero as viscosity is decreased (Reynolds number increased). This phenomenon—anomalous dissipation—is sometimes called the ‘zeroth law of turbulence’ as it underpins many celebrated theoretical predictions. Another robust feature observed in turbulence is that velocity structure functionsSp(ℓ):=⟨|δℓu|p⟩exhibit persistent power-law scaling in the inertial range, namelySp(ℓ)∼|ℓ|ζpfor exponentsζp>0over an ever increasing (with Reynolds) range of scales. This behaviour indicates that the velocity field retains some fractional differentiability uniformly in the Reynolds number. The Kolmogorov 1941 theory of turbulence predicts thatζp=p/3for allpand Onsager’s 1949 theory establishes the requirement thatζp≤p/3forp≥ 3for consistency with the zeroth law. Empirically,ζ2⪆2/3andζ3⪅1, suggesting that turbulent Navier–Stokes solutions approximate dissipative weak solutions of the Euler equations possessing (nearly) the minimal degree of singularity required to sustain anomalous dissipation. In this note, we adopt an experimentally supported hypothesis on the anti-alignment of velocity increments with their separation vectors and demonstrate that the inertial dissipation provides a regularization mechanism via the Kolmogorov 4/5-law.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.
Extreme events in transitional turbulence
Authors: Gomé Sébastien , Tuckerman Laurette S. , Barkley Dwight
Published: May 2022

Transitional localized turbulence in shear flows is known to either decay to an absorbing laminar state or to proliferate via splitting. The average passage times from one state to the other depend super-exponentially on the Reynolds number and lead to a crossing Reynolds number above which proliferation is more likely than decay. In this paper, we apply a rare-event algorithm, Adaptative Multilevel Splitting, to the deterministic Navier–Stokes equations to study transition paths and estimate large passage times in channel flow more efficiently than direct simulations. We establish a connection with extreme value distributions and show that transition between states is mediated by a regime that is self-similar with the Reynolds number. The super-exponential variation of the passage times is linked to the Reynolds number dependence of the parameters of the extreme value distribution. Finally, motivated by instantons from Large Deviation theory, we show that decay or splitting events approach a most-probable pathway.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.
Self-similarity in turbulence and its applications
Authors: Ohkitani Koji
Published: May 2022

First, we discuss the non-Gaussian type of self-similar solutions to the Navier–Stokes equations. We revisit a class of self-similar solutions which was studied in Canonne
et al
. (1996
Commun. Partial. Differ. Equ.
21
, 179–193). In order to shed some light on it, we study self-similar solutions to the one-dimensional Burgers equation in detail, completing the most general form of similarity profiles that it can possibly possess. In particular, on top of the well-known source-type solution, we identify a kink-type solution. It is represented by one of the confluent hypergeometric functions, viz. Kummer’s function

M

. For the two-dimensional Navier–Stokes equations, on top of the celebrated Burgers vortex, we derive yet another solution to the associated Fokker–Planck equation. This can be regarded as a ‘conjugate’ to the Burgers vortex, just like the kink-type solution above. Some asymptotic properties of this kind of solution have been worked out. Implications for the three-dimensional (3D) Navier–Stokes equations are suggested. Second, we address an application of self-similar solutions to explore more general kind of solutions. In particular, based on the source-type self-similar solution to the 3D Navier–Stokes equations, we consider what we could tell about more general solutions.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.
Self-similar hierarchy of coherent tubular vortices in turbulence
Authors: Tsuruhashi Tomonori , Goto Susumu , Oka Sunao , Yoneda Tsuyoshi
Published: May 2022

Energy transfers from larger to smaller scales in turbulence. This energy cascade is a process of the creation of smaller-scale coherent vortices by larger ones. In our recent study (Yoneda, Goto and Tsuruhashi 2022
Nonlinearity
35
, 1380-1401), we reformulated the energy cascade in terms of this stretching process and derived the

−
5

/

3

law of the energy spectrum under physically reasonable assumptions. In the present study, we provide a quantitative verification of these assumptions by using direct numerical simulations. We decompose developed turbulence in a periodic cube into scales by using the band-pass filter and identify the axes of coherent tubular vortices by the low-pressure method. Even when the turbulent kinetic energy and its dissipation rate temporally fluctuate about their temporal means, the total length of the vortices at each scale varies little with time. This result is consistent with our assumption of the temporal stationarity on the vorticity decomposition. The present numerical analysis also shows that the hierarchy of vortex axes is self-similar in a wide range of scales, i.e. in the inertial range and a lower part of the dissipation range and that the volume fraction occupied by the tubular vortices at each scale is independent of the scale.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.
On the Prandtl–Kolmogorov 1-equation model of turbulence
Authors: Kean Kiera , Layton William , Schneier Michael
Published: May 2022

We prove an estimate of total (viscous plus modelled turbulent) energy dissipation in general eddy viscosity models for shear flows. The ratio of the near wall average viscosity to the effective global viscosity is the key parameter in the estimate. This result is then applied to the 1-equation, URANS model of turbulence for which this ratio depends on the specification of the turbulence length scale. The model, which was derived by Prandtl in 1945, is a component of a 2-equation model derived by Kolmogorov in 1942 and is the core of many unsteady, Reynolds averaged models for prediction of turbulent flows. Let
τ
denote a selected time scale. Away from walls, interpreting an early suggestion of Prandtl, we set

l
=

2

k

1

/

2

τ
.

In the near-wall region analysis suggests replacing the traditional

l
=
0.41
d

(

d
=

wall normal distance) with

l
=
0.41
d

d

/

L

giving

l
=
min

{

2

k

 

1

/

2

τ
,
 
0.41
d

d
L

}

.

This specification of

l

results in a simpler model with correct near wall asymptotics. Its energy dissipation rate scales no larger than the physically correct

O

(

U

3

/

L
)

, balancing energy input with energy dissipation.

This article is part of the theme issue ‘Mathematical problems in physical fluid dynamics (part 2)’.
Proteome Remodeling of the Eye Lens at 50 Years Identified with Data-Independent Acquisition
Authors: Cantrell Lee S. , Schey Kevin L.
Published: May 2022

The eye lens is responsible for focusing and transmitting light to the retina. The lens does this in the absence of organelles yet maintains transparency for at least five decades before onset of age-related nuclear cataract (ARNC). It is hypothesized that oxidative stress contributes significantly to ARNC formation. It is additionally hypothesized that transparency is maintained by a microcirculation system (MCS) that delivers antioxidants to the lens nucleus and exports small molecule waste. Common data-ependent acquisition (DDA) methods are hindered by dynamic range of lens protein expression and provide limited context to age-related changes in the lens. In this study we utilized data-independent acquisition (DIA) mass spectrometry to analyze the urea insoluble, membrane protein fractions of 16 human lenses subdivided into three spatially distinct lens regions to characterize age-related changes, particularly concerning the lens MCS and oxidative stress response. In this pilot cohort, we measured 4,788 distinct protein groups, 46,681 peptides, and 7,592 deamidated sequences, more than in any previous human lens DDA approach. Our results reveal age-related changes previously known in lens biology and expand on these findings, taking advantage of the rich dataset afforded by DIA. Principally, we demonstrate that a significant proteome remodeling event occurs at approximately 50 years of age, resulting in metabolic preference for anaerobic glycolysis established with organelle degradation, decreased abundance of protein networks involved in calcium-dependent cell-cell contacts while retaining networks related to oxidative stress response. Further, we identified multiple antioxidant transporter proteins not previously detected in the human lens and describe their spatiotemporal and age-related abundance changes. Finally, we demonstrate that aquaporin-5, among other proteins, is modified with age by PTMs including deamidation and truncation. We suggest that the continued accumulation of each of these age-related outcomes in proteome remodeling contribute to decreased fiber cell permeability and result in ARNC formation.
Modulation of Tau Tubulin Kinases (TTBK1 and TTBK2) Impacts Ciliogenesis
Authors: Potjewyd Frances M. , Marquez Ariana B. , Chaikuad Apirat , Howell Stefanie , Dunn Andrea S. , Beltran Alvaro A. , Smith Jeffery L. , Drewry David H. , Beltran Adriana S. , Axtman Alison D.
Published: May 2022

Tau tubulin kinase 1 and 2 (TTBK1 and TTBK2) are highly homologous kinases that are expressed and mediate disease-relevant pathways predominantly in the brain. Distinct roles for TTBK1 and TTBK2 have been delineated. While efforts have been devoted to characterizing the impact to TTBK1 inhibition in diseases like Alzheimer’s disease and amyotrophic lateral sclerosis, TTBK2 inhibition has been less explored. TTBK2 serves a critical function during cilia assembly. Given the biological importance of these kinases, we designed a targeted library from which we identified several chemical tools that engage TTBK1 and TTBK2 in cells and inhibit their downstream signaling. Indolyl pyrimidinamine 10 significantly reduced the expression of primary cilia on the surface of human induced pluripotent stem cells (iPSCs). Furthermore, analog 10 phenocopies TTBK2 KO in iPSCs, confirming an essential role for TTBK2 in ciliogenesis.
Single-cell atlas of mouse limb development reveals a complex spatiotemporal dynamics of skeleton formation
Authors: Markman Svetlana , Zada Mor , David Eyal , Giladi Amir , Amit Ido , Zelzer Elazar
Published: May 2022

Limb development has long served as a model system for coordinated spatial patterning of progenitor cells. Here, we identify a population of naïve limb progenitors and show that they differentiate progressively to form the skeleton in a complex nonconsecutive three-dimensional pattern.

Single-cell RNA sequencing of the developing mouse forelimb revealed three progenitor states: naïve, proximal and autopodial, as well as Msx1 as a marker for the naïve progenitors. In vivo lineage tracing confirmed this role and localized the naïve progenitors to the outer margin of the limb, along the anterior-posterior axis. Sequential pulse-chase experiments showed that the progressive transition of Msx1+ naïve progenitors into proximal and autopodial progenitors coincides with their differentiation to Sox9+ chondroprogenitors, which occurs along all the forming skeletal segments.

Indeed, tracking the spatiotemporal sequence of differentiation showed that the skeleton forms progressively in a complex pattern. These findings suggest a new model for limb skeleton development.
Analysis of front end dynamic in the value co-creation with multiple stakeholders
Authors: Takahashi Sérgio , Takahashi Vania Passarini
Published: May 2022

Purpose

This study aims to analyze the dynamic of front end development (discover, define and create/analysis and test phases) in the co-creation with multiple stakeholders taking into account the value creation and capture process in a strategic business, consulting project, adding knowledge sharing flows.

Design/methodology/approach

The first phase of the study consisted of a review of the narrative literature. The method chosen for analyzing the findings is the narrative synthesis, which sought to identify and show the complementarity between the areas studied. Then, a summary of the review presents a conceptual structure. At the third phase of the study consisted of a field survey characterized for being a descriptive-exploratory and qualitative investigation based on a single case study.

Findings

For the results, three phases of evolution in the relationships among stakeholders can be characterized, namely: formation, strengthening and integration. With regard to value capture, it is also possible to characterize three phases of simultaneous non-linear evolution: sharing of perceptions, ideas and experiences, self-reflection, and vision and solution. With regard to knowledge sharing, two important flows were characterized: solution development and socialization and communication, in which there is a greater relationship with the development of trust, commitment, tie strengthening and shared vision. And some insights from the perspective of integrating dynamic capabilities and front end with value co-creation with multiple stakeholders.

Originality/value

Practical and theorical results of the evolution of value co-creation on the front end phases dynamic.
The effect of R&D activities on the market response and company's performance during the shock caused by the COVID-19 pandemic in Iran
Authors: Behbahaninia Parisa Saadat , Golbidi Mohadeseh
Published: May 2022

Purpose

The purpose of this study is to investigate whether research and development (R&D) activities reduce the performance damage caused by a critical situation, such as the COVID-19 pandemic, or not. Also, this study tries to explain whether the market in its reactions pays attention to companies' R&D activities or not during the COVID-19 critical situation.

Design/methodology/approach

The official announcement of the COVID-19 disease in Iran is considered the date of the event in this study. To consider the effect of R&D activities on the performance, three similar time periods before and after the coronavirus pandemic have been considered. Due to the widespread prevalence of coronavirus in Iran, this country has been selected to answer the research questions.

Findings

The results showed that the companies that have more R&D activities performed better than other companies during this period and were able to better manage this crisis. Furthermore, companies with more R&D activities suffered lower abnormal returns during coronavirus shocks than other companies.

Research limitations/implications

Based on the research results, the issues that were discussed on the importance of R&D activities in the accounting literature is confirmed, and the results show the importance of R&D activities on the company's ability to overcome crises.

Practical implications

Based on the results of this research, it can be suggested that even in difficult and critical conditions, investment in R&D activities should not be stopped and decrease.

Originality/value

In the accounting literature, the long-term effect of R&D activities on the survival of companies has always been considered. In this study, the effect of R&D activities on market response and firm performance in a real shock is investigated, which is the innovation of this research.
A grey-based framework for circular supply chain management: a forward step towards sustainability
Authors: Khan Shahbaz , Haleem Abid , Khan Mohd Imran
Published: May 2022

Purpose

Circular supply chain management (CSCM) has the potential to compensate for the drawbacks of the linear supply chain model. Therefore, the objective of this study is to identify and prioritise the significant enablers related to the effective management of the circular supply chain (CSC).

Design/methodology/approach

The significant enablers of CSCM are identified through a two-step process of literature review and grey-Delphi approach. Further, an integrated grey-based Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is applied to prioritise these enablers.

Findings

This study proposes a grey-based framework to identify and evaluate the enablers associated with CSCM. A total of 12 significant CSCM enablers are finalised per the proposed framework. The findings suggest that the top three enablers are "long-term planning", "development of CE culture" and "alignment of CE goals with strategic objectives". These enablers require the attention of the top management and supply chain partner on priority.

Research limitations/implications

This study identifies 12 enablers through the literature review, so there is a possibility to overlook some significant enablers. However, the expert's input is used to finalise and analyse the enablers, which can be biased towards their working level.

Originality/value

This study proposes a grey-based framework to identify and analyse the CSC enablers rarely investigated in the contemporary literature. The paper is strong in methodological contributions and gives practitioners and researchers a better framework for CSCM.
The influence of abusive supervision on employee engagement, stress and turnover intention
Authors: Oliveira Lucia B. , Najnudel Priscila Sarmento
Published: May 2022

Purpose

The purpose of this research was to investigate the influence of abusive supervision on work engagement, stress and turnover intention of subordinates. It was also proposed that work engagement and stress mediate the relationship between abusive supervision and turnover intention. Self-determination theory and the job demands-resources (JD-R) model provide the theoretical framework for the hypotheses.

Design/methodology/approach

The sample of this study consisted of 172 employees from public and private companies operating in different sectors of the economy. The hypotheses were tested through multiple regression analysis.

Findings

The results show that abusive supervision negatively influences engagement and contributes to increasing subordinates' stress and turnover intention. The study also found that the relationship between abusive supervision and turnover intention is mediated by engagement, but not by stress.

Research limitations/implications

Data was obtained from a convenience sample and cannot, therefore, be generalized.

Practical implications

The study results suggest that employees are prone to leave an organization when they are subordinated to abusive leaders, corroborating the idea that workers choose organizations but leave their leaders. This, in turn, reinforces the importance of adopting proper leadership selection and training processes.

Originality/value

This research addresses the dark side of the relationship between superiors and subordinates, which has been scarcely examined in the Brazilian literature. It also draws attention to different harmful consequences associated with dysfunctional behaviors of professionals that hold leadership positions in organizations.
Effect of Shadow Banking Activities on Firm Risk and Performance: Entrusted Loan Evidence from Chinese Listed Firms*
Authors: Wang Xiaoyan , Qiao Sijia , Shen Chung‐Hua , Wu Meng‐Wen , Wang Juan
Published: May 2022

This study investigates the effect of non‐financial firms' activities in shadow banking on firm risk and performance. Using manually collected data of entrusted loans from Chinese listed firms, we find that lending firms' bankruptcy risk and performance increases from their engagement of entrusted loan businesses in the year the loans are issued and in the following year. Further, firms' risk increases and performance improves significantly when firms are financially healthy, financially constrained, and non‐state‐owned. Overall, our findings provide policy implications that the risk of shadow banking activities must be cautious.
Exploring the role of Northeast Atlantic cod in the Barents Sea food web using a multi‐model approach
Authors: Nilsen Ina , Hansen Cecilie , Kaplan Isaac , Holmes Elizabeth , Langangen Øystein
Published: May 2022

It is commonly accepted that no ecosystem model is the ‘best’, but rather that ecosystem models should be used in ensembles. This is also the case for the Barents Sea ecosystem, where we have used two different ecosystem models to explore the role of the top‐predator Northeast Arctic (NEA) stock of Atlantic cod (Gadus morhua, Gadidae) in the food web. The two models differ in complexity; Gompertz being less complex in terms of food web (7 components) and processes compared to the complex Nordic and Barents Seas Atlantis model (53 components). On the other hand, Gompertz provides thousands of stochastic realizations for each scenario, whereas Atlantis provides only one deterministic simulation. To compare the response to changes in NEA cod on two key prey species, capelin (Mallotus villosus, Osmeridae) and polar cod (Boreogadus saida, Gadidae), we perturbed the historical fishing pressure by ±50% and used the same NEA cod biomass in both models. Even though the links between NEA cod and the prey species are similar in the two models, the results from the study reveal that indirect effects through other food‐web components might be as important as direct predator–prey interactions. Differences in spatial structure and overlap between species also influence the species response to the perturbations. In this study, we focus on the mechanisms that drives the changes in the models, and advise on potential consequences for fisheries management. The two models can complement each other, and the differences between them point to areas where more knowledge is needed.