bluuebunny/crossref_metadata_2025 huggingface dataset:
An exactly solvable predator prey model with resetting
Authors: Evans Martin R , Majumdar Satya N , Schehr Grégory
Published: May 2022

We study a simple model of a diffusing particle (the prey) that on encounter with one of a swarm of diffusing predators can either perish or be reset to its original position at the origin. We show that the survival probability of the prey up to time t decays algebraically as ∼t
−θ(p,γ) where the exponent θ depends continuously on two parameters of the model, with p denoting the probability that a prey survives upon encounter with a predator and γ = D

A
/(D

A
+ D

B
) where D

A
and D

B
are the diffusion constants of the prey and the predator respectively. We also compute exactly the probability distribution P(N|t
c) of the total number of encounters till the capture time t
c and show that it exhibits an anomalous large deviation form

P

(

N
|

t

c

)

∼

t

c

−
Φ

N

ln

t

c

=
z

for large t
c. The rate function Φ(z) is computed explicitly. Numerical simulations are in excellent agreement with our analytical results.
Copolymeric stars adsorbed at a surface and subject to a force: a self-avoiding walk model
Authors: Janse van Rensburg E J , Whittington S G
Published: May 2022

We consider a model of star copolymers, based on self-avoiding walks, where the arms of the star can be chemically distinct. The copolymeric star is attached to an impenetrable surface at the end of an arm and the different monomers constituting the star have different interaction strengths with the surface. When the star is adsorbed at the surface it can be desorbed by applying a force, either at a vertex of degree 1 or at the central vertex of the star. We give some rigorous results about the free energy of the system and use these to establish the general form of the phase diagrams, and the orders of certain phase transitions in the system. We also consider the special case of spiders, i.e. stars constrained to have all the endpoints of their arms in the surface.
Halos and undecidability of tensor stable positive maps
Authors: van der Eyden Mirte , Netzer Tim , De las Cuevas Gemma
Published: May 2022

A map

P

is tensor stable positive (tsp) if

P

⊗
n

is positive for all n, and essential tsp if it is not completely positive or completely co-positive. Are there essential tsp maps? Here we prove that there exist essential tsp maps on the hypercomplex numbers. It follows that there exist bound entangled states with a negative partial transpose (NPT) on the hypercomplex, that is, there exists NPT bound entanglement in the halo of quantum states. We also prove that tensor stable positivity on the matrix multiplication tensor is undecidable, and conjecture that tensor stable positivity is undecidable. Proving this conjecture would imply existence of essential tsp maps, and hence of NPT bound entangled states.
Study Of Health Aspects On Facilities And Infrastructure in Corridor 1 Bus Rapid Transit (BRT) Trans Semarang
Authors: Manullang Okto Risdianto , Haryanto Ragil , Ramadhan Danny Rizky
Published: May 2022

This study aimed to determine the facilities and infrastructures health aspects of the Corridor I Trans Semarang at Mangkang Terminal-Penggaron Terminal, also to determine the expectations of Corridor 1 Trans Semarang users on the health aspects of future infrastructure. This research method uses customer satisfaction index and importance-performance analysis. The results of the study indicate a percentage level of 50% for facilities and 39% for infrastructure users who feel “less satisfied” with the health aspect of the Corridor 1 Trans Semarang infrastructure facilities that have been provided. Users’ expectations in the future are to limit and maintain capacity at the Corridor 1 Trans Semarang bus and shelters, which is a top priority. This was followed by the provision of hand sanitizers, the reduction of seats and handgrip, as well as the use of masks on the Corridor I Trans Semarang bus which became the second priority. Meanwhile, the main priority expectations from users for health infrastructure in addition to limiting and maintaining capacity are the provision of a standing sticker for the seat barrier and an appeal for the application of health protocols/PHBS/cough etiquette at the Trans Semarang shelters. Furthermore, the provision of hand sanitizers, the implementation of non-cash payments, and controlling the use of masks are the second priority expectations of Trans Semarang users.
Dynamics of Supply-Demand Online Motorcycle Taxis in Urban Area
Authors: Subandi Adi , Karsaman Rudy Hermawan , Lubis Al Rasyid Harun
Published: May 2022

In Indonesia’s urban area, online motorcycle taxis “Ojol” have grown significantly, especially for support mobilization and other activities. Currently, it was considered “oversupply” indicated by not accepting new registrations for a new driver and decreasing the existing driver incomes. With the proposed development and modification model for controlling online motorcycle taxis numbers in urban areas, it is hoped that the equilibrium point for the provision of online motorcycle taxis numbers can be optimal, not only impacting partners’ welfare but a more comprehensive urban transportation system. Based on a pilot survey with data ranging from 50 respondents, each for passengers and drivers, with SEM models, it was indicated that level of user satisfaction, which was affected by income level has a higher influence (-0.039) than movement characteristics (0.011), while at consistency level analysis based on driver’s perception indicates that safety aspect has a higher effect (-0.288) than income level (0.251). Output analysis is still provisional, more data is needed to represent a more comprehensive output.
Climatic changes in European Russia and the Republic of Belarus in the XX-XXI centuries under the influence of atmospheric circulation
Authors: Perevedentsev Yu P , Sherstyukov B G , Shantalinsky K M , Guryanov V V , Mirsaeva N A , Lopukh P S , Gledko Yu A , Ismagilov N V , Nikolaev A A
Published: May 2022

Climatic changes in the atmosphere from the Earth’s level to the altitude of 80 km in Russia and the Republic of Belarus (RB) are considered using data from 1251 stations of RIHMI-WDC (1976-2019), ERA5 reanalysis (1979-2019), and 99 long-row stations located in the European part of Russia (ER) and the Republic of Belarus (RB). An analysis of constructed trends in the air temperature (AT) and atmospheric precipitation is made to assess the spatial and temporal variability of the thermal and humidity regimes in the territory. Some differences in the rates of warming between the winter and summer seasons, troposphere and stratosphere are revealed. Near the earth's surface, the rate of warming is maximum in polar latitudes; the summer stratosphere cools more strongly than the winter one. To assess the influence of atmospheric circulation on the thermal regimes of ER and RB, the correlation coefficients between AT and circulation indices AO, NAO, SCAND, and EAWR are calculated. Using a low-pass Potter filter, a 40-year periodicity of temperature fluctuations in the ER and RB in November is revealed. In the winter stratosphere, a relationship between temperature fluctuations in the polar zone and the Arctic oscillation index is found. The spring restructuring of the stratospheric circulation occurs with a delay if strong sudden stratospheric warmings (SSW) occur in the stratosphere in winter.
Comparative characteristics of gap filling methods in high-frequency data of micrometeorological measurements
Authors: Drozd I D , Gavrikov A V , Stepanenko V M
Published: May 2022

This article is devoted to one of the most complex technical aspects of the primary processing of micrometeorological data. The article contains a description of basic algorithms for restoring missing values in time series of data. The gap filling methods implemented by the authors on the basis of the thus described algorithms are tested using an example of filling-in generated gaps in series of temperature and vertical wind speed. The series of high-frequency measurements of an acoustic anemometer installed on the micrometeorological tower of the meteorological observatory (MO) of Moscow State University (MSU) are used as test data. As a result of this review of gap-filling methods, the effectiveness of various methods for filling-in missing values is assessed.
Severe hard rime accretion in the Far North of Russia: observations and modeling
Authors: Leonov I I , Sokolikhina N N
Published: May 2022

Severe weather means any hazardous meteorological phenomena which can cause significant damage, serious social disruption, or loss of human life. Such weather phenomena include thunderstorms, hurricanes, tornados, ice storms, and many others. The main purpose of this research is a study of formation mechanisms of rime accretion and methods for their prediction. This is necessary to forecast these phenomena and minimize their economic and other losses. This work is dedicated to a detailed study of an extraordinary case of formation of rime accretion in the territory of the Yamalo-Nenets Autonomous Okrug, which occurred in early January 2016. Numerical experiments are used for an analysis of various methods for predicting areas of possible ice accretion formation. For the numerical experiments, the atmospheric model WRF-ARW has been chosen. For a theoretical assessment of icing intensity, the Makkonen formula is used. The results of this research are as follows: the main mechanisms of ice accretion formation have been identified for the territory of the Far North of Russia. Numerical experiments with the WRF-ARW model have been successful and reproduced the main signs of rime accretion. The results show that the model has successfully reproduced the icing start time and the icing intensity distribution throughout the entire numerical experiment. The quality of the model's assessment of the mass of rime accretion is difficult to estimate from data of only two meteorological stations; however, the values obtained are close to the observed ones.
Research on arc root stagnation when small current is interrupted in self-excited circuit breaker
Authors: PENG Shidong , LI Jing , CAO Yundong , HUANG Chongyang , LIU Shuxin
Published: May 2022

The self-excited DC air circuit breaker (SE-DCCB) has been widely used in urban rail transit due to its excellent stability. It can realize forward and reverse interruption, but has difficulty interrupting small currents due to the phenomenon of arc root sticking at the entrance of the arc chamber in the splitting process, which is known as arc root stagnation. A coupling model of the self-excited magnetic field and magnetohydrodynamics is established for the SE-DCCB with the traditional structure. The magnetic field, temperature and airflow distribution in the arc chamber are investigated with an interrupting current of 150 A. The simulation results show that the direction and magnitude of the magnetic blowout force are the dominant factors in the arc root stagnation. The local high temperature of the arc chamber due to arc root stagnation increases the obstruction effect of the airflow vortex on the arc root movement, which significantly increases the arc duration time of small current interruption. Based on the research, the structure of the magnetic conductance plate of the actual product is improved, which can improve the direction and magnitude of the magnetic blowout force at the arc root so as to restrain the development of the airflow vortex effectively and solve the problem of arc root stagnation when the small current is interrupted. The simulation results show that the circuit breaker with improved structure has a better performance for a small current interruption range from 100 A to 350 A.
Finite dimensional models for random microstructures
Authors: Grigoriu M.
Published: May 2022

Finite dimensional (FD) models, i.e., deterministic functions of space depending on finite sets of random variables, are used extensively in applications to generate samples of random fields

Z
(
x
)

Z(x)

and construct approximations of solutions

U
(
x
)

U(x)

of ordinary or partial differential equations whose random coefficients depend on

Z
(
x
)

Z(x)

. FD models of

Z
(
x
)

Z(x)

and

U
(
x
)

U(x)

constitute surrogates of these random fields which target various properties, e.g., mean/correlation functions or sample properties. We establish conditions under which samples of FD models can be used as substitutes for samples of

Z
(
x
)

Z(x)

and

U
(
x
)

U(x)

for two types of random fields

Z
(
x
)

Z(x)

and a simple stochastic equation. Some of these conditions are illustrated by numerical examples.
Robust differential abundance test in compositional data
Authors: Wang Shulei
Published: May 2022

Differential abundance tests for compositional data are essential and fundamental in various biomedical applications, such as single-cell, bulk RNA-seq and microbiome data analysis. However, because of the compositional constraint and the prevalence of zero counts in the data, differential abundance analysis on compositional data remains a complicated and unsolved statistical problem. This article proposes a new differential abundance test, the robust differential abundance test, to address these challenges. Compared with existing methods, the robust differential abundance test is simple and computationally efficient, is robust to prevalent zero counts in compositional datasets, can take the data’s compositional nature into account, and has a theoretical guarantee of controlling false discoveries in a general setting. Furthermore, in the presence of observed covariates, the robust differential abundance test can work with covariate-balancing techniques to remove potential confounding effects and draw reliable conclusions. The proposed test is applied to several numerical examples, and its merits are demonstrated using both simulated and real datasets.
A Review of the Ring Trial Design for Evaluating Ring Interventions for Infectious Diseases
Authors: Butzin-Dozier Zachary , Athni Tejas S , Benjamin-Chung Jade
Published: May 2022

In trials of infectious disease interventions, rare outcomes and unpredictable spatiotemporal variation can introduce bias, reduce statistical power, and prevent conclusive inferences. Spillover effects can complicate inference if individual randomization is used to gain efficiency. Ring trials are a type of cluster-randomized trial that may increase efficiency and minimize bias, particularly in emergency and elimination settings with strong clustering of infection. They can be used to evaluate ring interventions, which are delivered to individuals in proximity to or contact with index cases. We conducted a systematic review of ring trials, compare them with other trial designs for evaluating ring interventions, and describe strengths and weaknesses of each design. Of 849 articles and 322 protocols screened, we identified 26 ring trials, 15 cluster-randomized trials, 5 trials that randomized households or individuals within rings, and 1 individually randomized trial. The most common interventions were postexposure prophylaxis (n = 23) and focal mass drug administration and screening and treatment (n = 7). Ring trials require robust surveillance systems and contact tracing for directly transmitted diseases. For rare diseases with strong spatiotemporal clustering, they may have higher efficiency and internal validity than cluster-randomized designs, in part because they ensure that no clusters are excluded from analysis due to zero cluster incidence. Though more research is needed to compare them with other types of trials, ring trials hold promise as a design that can increase trial speed and efficiency while reducing bias.
Diversity and phylogeny of the bacterial strains isolated from nodules of fenugreek (Trigonella foenum-graecum L.) in Iran
Authors: Borhani Behzad , Khodakaramian Gholam , Velázquez Encarna
Published: May 2022

The diversity of fenugreek (Trigonella foenum-graecum L.) microsymbionts has been barely studied even though it is of great interest for being a spice and a medicinal plant. Here, we analyzed 59 bacterial strains isolated from fenugreek nodules originating from different geographic and climatic areas of Iran. Most of these strains exhibit phenotypic characteristics compatible with rhizobia and they nodulate fenugreek. Analysis of the recA and atpD genes shows that representative strains of ERIC–BOX-PCR groups cluster with the type strains of Ensifer meliloti and E. kummerowiae as well as with strains capable of nodulating different Trigonella species found in other countries. The closeness of E. meliloti and E. kummerowiae suggests there is a need to revise the taxonomic status of the latter species. The nodC gene analysis shows that most Trigonella-nodulating strains belong to the symbiovar meliloti except those nodulating Trigonella arcuata in China, which belong to the symbiovar rigiduloides. This analysis shows that the type strains of E. kummerowiae, E. meliloti, and E. medicae belonged to three well-defined groups within the symbiovar meliloti, with the Iranian strains belonging to the E. kummerowiae subgroup. The small group of strains unable to nodulate fenugreek isolated in this study belong to Enterobacter cloacae, reported for the first time as being a possible endophyte of fenugreek nodules.
Responding to Local Needs by Mobilizing Community Assets: Age-Friendly Community Initiatives During the COVID-19 Pandemic
Authors: Greenfield Emily A , Pestine-Stevens Althea , Scher Clara
Published: May 2022

Background and Objectives

Age-friendly community initiatives (AFCIs) strive to make localities better for long and healthy lives by fostering improvements across social, physical, and service environments. Despite the heightened need for community supports during the coronavirus disease 2019 pandemic, very little research has addressed the work of AFCIs in the context of this crisis. We aimed to develop theory on how AFCI core teams have contributed to community responses during the pandemic, as well as what contexts have influenced the initiatives’ ability to contribute.

Research Design and Methods

As part of a multiyear, community-partnered study on the development of philanthropically supported initiatives in northern New Jersey, we conducted qualitative interviews with 8 AFCI core teams during the winter of 2020–2021. The interviews focused on the leaders’ efforts at that time, with probing questions concerning enabling factors for their community responses. We analyzed the data using an inductive coding process encompassing open, axial, and subcoding.

Results

The analysis indicated four distinct roles of AFC core groups: good community partner, creator, advocate, and communications broker. We further found that AFC leaders primarily drew on three types of capital—human, social, and tangible—to enact these roles, oftentimes in cumulative ways.

Discussion and Implications

We interpret our study’s findings and their implications by integrating insights from theories of social impact. We further highlight the importance of continued research on community-centered approaches to promote aging in community during times of societal crisis, and otherwise.
Do Sexual Expectations Matter for Older Men and Women? Anticipated Sexual Futures and Late-Life Sexuality Over Two Decades
Authors: Schafer Markus H , Upenieks Laura
Published: May 2022

Background and Objectives

Expectations across a variety of life domains appear to shape the aging process, giving weight to the role of self-fulfilling prophecies in later life. Sexuality is one area where the power of expectations is not well-understood. We investigated whether 10-year sexual expectations were associated with sexual satisfaction and sexual frequency a decade on among older heterosexual coupled adults. We further examined whether sexual expectations could offset the sex-constraining impact of functional limitation onset.

Research Design and Methods

We used 3 waves of the Midlife Development in the United States study (1995, 2005, 2014), a nationally representative panel survey. Analyses consider adults aged 45+ in 1995 who had a spouse or romantic partner at 2 consecutive waves. Associations between sexual expectations and eventual sexual satisfaction and frequency were estimated with multivariable generalized estimating equations. Moderation analyses examined whether between-wave onset of functional limitations had less influence on sexuality outcomes when combined with a high initial level of sexual expectations.

Results

Sexually optimistic participants reported more sexual satisfaction and higher sexual frequency a decade later. Though the onset of functional limitations tended to suppress sexual frequency for women, the probability of having weekly sex was significantly higher among such women if they had high rather than low sexual expectations.

Discussion and Implications

Results suggest that, similar to other life domains, expectations shape the sexual experience of older adults. Clinicians and care providers may consider ways to help foster realistic optimism about sexuality among older men and women.
On the Other Side of the Fence: Property Rights and Productivity in the United States
Authors: Bühler Mathias
Published: May 2022

Can well-defined access rights to publicly owned land be as effective as privatization in increasing productivity and wealth? In this paper, I evaluate the impact of public property rights using the 1934 Taylor Grazing Act, which determined secure access rights for ranchers to newly created, large grazing districts in the Western United States. Using satellite-based vegetation data, I exploit spatial discontinuities across grazing district boundaries and find that public lands with well-defined access rights for ranchers are at least 10% more productive than lands without. Immediately after establishing grazing districts, ranchers inside these districts held more cattle, and reported higher income and farm values than their counterparts outside. Despite ranchers being unable to invest in publicly owned lands, these magnitudes are similar to outright privatization. Instead, I argue that secure access rights resolve uncertainty around future usage and align the incentives of ranchers and regulators, thus incentivizing sustainable and profitable usage. I provide two results supporting this hypothesis: Areas with stronger pre-reform state capacity show larger increases in vegetation; and, monthly patterns on vegetation are consistent with the adoption of productivity-increasing fallowing practices. I investigate alternative explanations, and find no empirical support for differential initial productivity, negative spillovers, or systematic local manipulation of boundaries.
Morphological Variation in the Wing Mite Periglischrus paracaligus (Acari: Spinturnicidae) Associated With Different Moving Strategies of the Host Leptonycteris yerbabuenae (Chiroptera: Phyllostomidae)
Authors: Zamora-Mejías Daniel , Ojeda Margarita , Medellín Rodrigo A , Rodríguez-Herrera Bernal , Morales-Malacara Juan B
Published: May 2022

We evaluated the morphometric variation of wing mite Periglischrus paracaligus Herrin and Tipton, along with the distribution of their host Leptonycteris yerbabuenae Martinez and Villa, in Mexico. A total of 115 female and 96 male specimens of P. paracaligus were used to conduct linear and geometric morphometric analyses. We assessed the influence of the geographic distribution of the migratory and nonmigratory populations of its bat host species on changes in size and shape on these parasites. Both analyses revealed high intraspecific variation in P. paracaligus, but subtle geographic differentiation. None of the approaches used identified a consistent pattern that separates unambiguously migratory from nonmigratory populations. Females presented more phenotypic variation than males and UPGMA analyses showed southern and northern colonies grouped in two distinct clades. Males on the other hand showed randomly grouped colonies with no geographic concordance. Interestingly, the most differentiated colony was the north Pacific colony of Jalisco. For both, males and females, isolation by distance (IBD) was not observed. We discuss these results as a possible scenario of contact between migratory populations located in northern Mexico with nonmigratory populations in other localities in central and southern Mexico conforming to a panmictic population along with their distribution range.
An experimental study on the torsional stiffness and limit torque of a jaw coupling with consideration of spacer's hardness and installation methods
Authors: Chen Chih-Ming , Chang Huey-Ling , Lee Chun-Ying
Published: May 2022

The jaw coupling with a flexible spacer is frequently used in the torque transmission between shafts with misalignment for machinery. Its torsional stiffness and limit torque closely determine the operational capacity and the dynamic characteristics of the system because the coupling is usually the most flexible link in the driving chain. In this study, the optimal design of a jaw coupling with an elastomeric spacer was investigated using the Taguchi method by considering four design factors: the tightening method of the clamping bolts, the tightening torque of the clamping bolts, the hardness of the thermoplastic polyether ester elastomer spacer and the installation angle between the two end blocks of the coupling. All specimens were tested by using an in-house torsion tester to record the torque-angular deformation responses. The results showed good reliability and repeatability, with a coefficient of variance within 5%. Spacer's hardness was found to be the most significant factor regarding the torsional stiffness, while the magnitude of the clamping torque had the most critical role in the limit torque. The estimation formulae for the torsional stiffness and limit torque of the jaw coupling were obtained by using the statistical regression of the measured data, respectively. Both formulae predicted the performance of the optimal designs within 5% of error compared to the confirmation tests.
Genetically encoded fluorescent sensors adapted to acidic pH highlight subdomains within the plant cell apoplast
Authors: Moreau Hortense , Gaillard Isabelle , Paris Nadine
Published: May 2022

Monitoring pH is one of the challenges in understanding diverse physiological regulations as well as ionic balance, especially in highly acidic environments such as the apoplast and the vacuole. To circumvent the poor efficiency of pH measurements below pH 5, we designed three genetically encoded sensors composed of two fluorescent proteins in tandem. We selected fluorescent protein pairs of low but sufficiently different pKa so that each protein could differentially sense the imposed pH. The generated tandems, named Acidin2, Acidin3, and Acidin4, were produced in Escherichia coli and extensively characterized. Altogether, these generated tandems cover a pH range of 3–8. The Acidins were targeted either for release in the apoplast (Apo) or for anchoring at the outer face of the plasma membrane (PM-Apo), with the fluorescent part exposed in the apoplast. Apoplastic Acidins in stably transformed Arabidopsis thaliana primary roots responded immediately and reversibly to pH changes, directly reporting physiological conditions related to cell elongation. In addition, membrane-anchored Acidins reveal a gradual acidification from the surface through the anticlinal wall of pavement cells, a process controlled at least partially by H+-ATPase activity.
4 Enforcement of Security Interests in Securities Under Uniform Law
Authors: Thomas Keijser
Published: May 2022

This chapter deals with the enforcement of security and other interests in intermediated and non-intermediated securities under uniform law. It discusses the UNIDROIT Convention on Substantive Rules for Intermediated Securities and the Convention of 5 July 2006 on the Law Applicable to Certain Rights in Respect of Securities Held with an Intermediary, which are included in the Uniform Law. It also reviews the enforcement of security and other interests in intermediated securities under Chapters III (transfer of intermediated securities) and V (special provisions in relation to collateral transactions) of the Geneva Securities Convention (GSC). The chapter explains the common characteristics and gaps of the relevant uniform law texts, including different aspects of their scope of application and definitions. It highlights the enforcement of a security interest in the case of the grantor’s insolvency.
8 Principles of Insolvency Law for Intermediated Securities
Authors: Thomas Keijser
Published: May 2022

This chapter focuses on the principles relating to the insolvency law and intermediated securities, including those reflected by the Geneva Securities Convention (GSC) and the Legislative Guide. It considers various examples of the treatment of issues under current laws, drawing on the UK and US law. It also identifies the most significant issues involving intermediated securities in the context of insolvency, which arise in insolvency proceedings and in the contemplation of potential future proceedings. The chapter offers suggestions for how States might address issues in insolvency in their domestic laws, providing a roadmap for the improvement of the relevant legal regimes. It reviews some perspectives on how ongoing and future developments in technology in relation to the financial markets may affect the holding of securities in the future.
Intermediated Securities
Authors: Gullifer Louise , Payne Jennifer
Published: May 2022

This chapter highlights the role of financial market infrastructures (FMIs) in the holding of securities. The rise of cross-border investments, the expansion of capital markets, and the increasing number of investors in securities contributed to a growing trend in the intermediation in the holding of securities. Despite such trend, domestic law dealing with transferable securities still assumes direct holding as the securities holding paradigm, thus overlooking the full range of changes intermediation brings. The chapter analyses the advantages and disadvantages in directly holding securities compared to holding them through intermediation and suggests that, for most market participants, the advantages outweigh the disadvantages. It also considers the responses of the law in Europe to intermediation, identifying their shortcoming and arguing in favour of legal, regulatory, or market changes, both at a national and supranational level, to ensure the implementation of the advantages of securities intermediation.
The Great Planetary Heist: theft and capture in star-forming regions
Authors: Daffern-Powell Emma C , Parker Richard J , Quanz Sascha P
Published: May 2022

Gravitational interactions in star-forming regions are capable of disrupting and destroying planetary systems, as well as creating new ones. In particular, a planet can be stolen, where it is directly exchanged between passing stars during an interaction; or captured, where a planet is first ejected from its birth system and is free-floating for a period of time, before being captured by a passing star. We perform sets of direct N-body simulations of young, substructured star-forming regions, and follow their evolution for 10 Myr in order to determine how many planets are stolen and captured, and their respective orbital properties. We show that in high-density star-forming regions, stolen and captured planets have distinct properties. The semimajor axis distribution of captured planets is significantly skewed to wider orbits compared to the semimajor axis distribution of stolen planets and planets that are still orbiting their parent star (preserved planets). However, the eccentricity and inclination distributions of captured and stolen planets are similar, but in turn very different to the inclination and eccentricity distributions of preserved planets. In low-density star-forming regions these differences are not as distinct but could still, in principle, be used to determine whether observed exoplanets have likely formed in situ or have been stolen or captured. We find that the initial degree of spatial and kinematic substructure in a star-forming region is as important a factor as the stellar density in determining whether a planetary system will be altered, disrupted, captured, or stolen.
Evolution of thermal and non-thermal radio continuum emission on kpc scales – predictions for SKA
Authors: Ghasemi-Nodehi M , Tabatabaei Fatemeh S , Sargent Mark , Murphy Eric J , Khosroshahi Habib , Beswick Rob , Bonaldi Anna , Schinnerer Eva
Published: May 2022

Resolved maps of the thermal and non-thermal radio continuum (RC) emission of distant galaxies are a powerful tool for understanding the role of the interstellar medium (ISM) in the evolution of galaxies. We simulate the RC surface brightness of present-day star-forming galaxies in the past at 0.15 < z < 3, considering two cases of radio size evolution: (1) no evolution and (2) same evolution as in the optical. We aim to investigate the (a) structure of the thermal and non-thermal emission on kpc scales, (b) evolution of the thermal fraction and synchrotron spectrum at mid-radio frequencies (≃1–10 GHz), and (c) capability of the proposed SKA phase 1 MID-frequency (SKA1-MID) reference surveys in detecting the RC emitting structures. The synchrotron spectrum flattens with z causing curvature in the observed mid-radio SEDs of galaxies at higher z. The spectral index reported in recent observational studies agrees better with the no size evolution scenario. In this case, the mean thermal fraction observed at 1.4 GHz increases with redshift by more than 30 per cent from z = 0.15 to z = 2 because of the drop of the synchrotron emission at higher rest-frame frequencies. More massive galaxies have lower thermal fractions and experience a faster flattening of the non-thermal spectrum. The proposed SKA1-MID band 2 reference survey, unveils the ISM in M51- and NGC 6946-like galaxies (with ${\rm M_{\star }}\simeq 10^{10}\, {\rm M}_{\odot }$) up to z = 3. This survey detects lower-mass galaxies like M33 (${\rm M_{\star }}\simeq 10^{9}\, {\rm M}_{\odot }$) only at low redshifts z ≲ 0.5. For a proper separation of the RC emitting processes at the peak of star formation, it is vital to include band 1 into the SKA1-MID reference surveys.
Associations of California’s Tobacco 21 Minimum Sales Age Law with Tobacco Use Among Sexual Minority Adolescents: A Trends Analysis
Authors: García-Ramírez Grisel , Islam Sabrina , Wharton Mary K , Grube Joel W
Published: May 2022

Introduction

In 2016, California enacted a law (T21) prohibiting tobacco product sales to individuals under 21 years of age. Given tobacco use disparities among sexual minority (SM) youth, this study investigated whether California’s T21 law was differentially associated with changes in tobacco use for SM and non-SM adolescents.

Aims and Methods

Secondary analyses of California Healthy Kids Survey data from 2013–2014 to 2018–2019 for 7th, 9th, and 11th graders (N = 2 229 401).

Results

Multilevel mixed-effects logistic regression analyses showed that SM students were more likely than non-SM students to report past-30-day and lifetime cigarette (odds ratio (OR) = 2.47; OR = 2.37), e-cigarette (OR = 1.21; OR = 1.10), smokeless tobacco use (OR = 1.95; OR = 1.56), and use of any tobacco product (OR = 1.94; OR = 1.61). Among SM youth, T21 was associated with significant reductions in lifetime e-cigarette use (OR = 0.66), and lifetime use of any tobacco products (OR = 0.75). These decreases generally were greater than or equivalent to those observed for non-SM youth. For 30-day e-cigarette and any tobacco use, SM youth showed no significant increases, whereas non-SM youth showed significant increases (OR = 1.06; OR = 1.11) following T21. T21 was associated with smaller increases in lifetime cigarette use (OR = 1.34), and larger increases for past-30-day and lifetime smokeless tobacco use (OR = 1.34; OR = 1.28) among SM students, to those observed for non-SM students.

Conclusions

California’s T21 policy may help reduce tobacco use disparities among SM students who are more at risk for tobacco use than their non-SM peers.

Implications

Research on associations of T21 laws with tobacco use among sexual minority (SM) adolescents is lacking. The potential for unintended consequences of T21 for these adolescents raises concerns about increased health disparities. Importantly, our study generally found California’s T21 was associated with reductions in tobacco use among SM students that were equivalent to or greater than those for non-SM students. Future research should investigate whether T21 laws and similar policies have differential effects for other marginalized groups and, if so, identify mechanisms that can be targeted in prevention efforts.
Receptor-like protein kinase BAK1 promotes K+ uptake by regulating H+-ATPase AHA2 under low potassium stress
Authors: Wang Zhi-Fang , Xie Zhong-Mei , Tan Ya-Lan , Li Jia-Ying , Wang Feng-Liu , Pei Dan , Li Zhen , Guo Yan , Gong Zhizhong , Wang Yi
Published: May 2022

Potassium (K+) is one of the essential macronutrients for plant growth and development. However, the available K+ concentration in soil is relatively low. Plant roots can perceive low K+ (LK) stress, then enhance high-affinity K+ uptake by activating H+-ATPases in root cells, but the mechanisms are still unclear. Here, we identified the receptor-like protein kinase Brassinosteroid Insensitive 1-Associated Receptor Kinase 1 (BAK1) that is involved in LK response by regulating the Arabidopsis (Arabidopsis thaliana) plasma membrane H+-ATPase isoform 2 (AHA2). The bak1 mutant showed leaf chlorosis phenotype and reduced K+ content under LK conditions, which was due to the decline of K+ uptake capacity. BAK1 could directly interact with the AHA2 C terminus and phosphorylate T858 and T881, by which the H+ pump activity of AHA2 was enhanced. The bak1 aha2 double mutant also displayed a leaf chlorosis phenotype that was similar to their single mutants. The constitutively activated form AHA2Δ98 and phosphorylation-mimic form AHA2T858D or AHA2T881D could complement the LK sensitive phenotypes of both aha2 and bak1 mutants. Together, our data demonstrate that BAK1 phosphorylates AHA2 and enhances its activity, which subsequently promotes K+ uptake under LK conditions.
Metabolic control of arginine and ornithine levels paces the progression of leaf senescence
Authors: Liebsch Daniela , Juvany Marta , Li Zhonghai , Wang Hou-Ling , Ziolkowska Agnieszka , Chrobok Daria , Boussardon Clément , Wen Xing , Law Simon R , Janečková Helena , Brouwer Bastiaan , Lindén Pernilla , Delhomme Nicolas , Stenlund Hans , Moritz Thomas , Gardeström Per , Guo Hongwei , Keech Olivier
Published: May 2022

Leaf senescence can be induced by stress or aging, sometimes in a synergistic manner. It is generally acknowledged that the ability to withstand senescence-inducing conditions can provide plants with stress resilience. Although the signaling and transcriptional networks responsible for a delayed senescence phenotype, often referred to as a functional stay-green trait, have been actively investigated, very little is known about the subsequent metabolic adjustments conferring this aptitude to survival. First, using the individually darkened leaf (IDL) experimental setup, we compared IDLs of wild-type (WT) Arabidopsis (Arabidopsis thaliana) to several stay-green contexts, that is IDLs of two functional stay-green mutant lines, oresara1-2 (ore1-2) and an allele of phytochrome-interacting factor 5 (pif5), as well as to leaves from a WT plant entirely darkened (DP). We provide compelling evidence that arginine and ornithine, which accumulate in all stay-green contexts—likely due to the lack of induction of amino acids (AAs) transport—can delay the progression of senescence by fueling the Krebs cycle or the production of polyamines (PAs). Secondly, we show that the conversion of putrescine to spermidine (SPD) is controlled in an age-dependent manner. Thirdly, we demonstrate that SPD represses senescence via interference with ethylene signaling by stabilizing the ETHYLENE BINDING FACTOR1 and 2 (EBF1/2) complex. Taken together, our results identify arginine and ornithine as central metabolites influencing the stress- and age-dependent progression of leaf senescence. We propose that the regulatory loop between the pace of the AA export and the progression of leaf senescence provides the plant with a mechanism to fine-tune the induction of cell death in leaves, which, if triggered unnecessarily, can impede nutrient remobilization and thus plant growth and survival.
Extraction and characterization of bovine collagen Type V and its effects on cell behaviors
Authors: Xu Jun , Luo Xi , Zhang Yang , Gao Jianping , Huang Ching-Cheng , Bai Xinpeng , Zhang Guifeng
Published: May 2022

Collagen Type V (Col. V) plays an essential role in cell behaviors and has attracted increasing attention in recent years. High-purity Col. V is needed for evaluating its biological properties. In this research, the enzymatic hydrolysis process was combined with ultrafiltration to purify Col. V from the bovine cornea. The purity of Col. V was determined to be above 90% by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and high-performance liquid chromatography methods. The effect of Col. V on cell behaviors was evaluated. The circular dichroism spectroscopy results demonstrated that the extracted Col. V exhibited a complete triple helix structure. SDS-PAGE suggested that the molecular weight of Col. V was 440 kDa. The self-assembly experiment revealed that the proportion of Col. V in the collagen mixture can affect the Col. I fiber diameter. The cell culture results implied that Col. V can inhibit fibroblasts (L929) proliferation. The L929 showed maximum mobility when the addition of Col. V was 30%. Thus, Col. V has the effect of inhibiting L929 proliferation and promoting migration. The high-purity Col. V provides useful information for further understanding its biological implications.
Efficacy and Safety of “Sleeper Plate” in Temporary Hemiepiphysiodesis and the Observation of “Tethering”
Authors: Gerges Mina , Messner Juergen , Lim Brittany , Chhina Harpreet , Cooper Anthony
Published: May 2022

Background:

Guided growth is commonly performed by placing an extraperiosteal 2-hole plate across the growth plate with one epiphyseal and one metaphyseal screw. Recent studies investigated the efficacy of the removal of the metaphyseal screw only (sleeper plate) after correction. They concluded the practice to be unnecessary as only 19% of patients showed recurrence of deformity. This study aims to examine the incidence of rebound and undesired bony in-growth of the plate (tethering) after metaphyseal screw removal only.

Methods:

In this retrospective case series, patient data on 144 plates inserted around the knee were obtained. Plates still in situ (n=69) at the time of study and full hardware removal (n=50) were excluded. The remaining 25 plates had only the metaphyseal screw removed after completed deformity correction. We analyzed the rate of tethering, rebound, and maintenance of correction in 2 age groups at latest follow (mean of 3.5 y). The Fisher exact test with Freeman-Halton extension was used to analyze categorical data and the Student t test for descriptive variables.

Results:

Twenty-five plates were identified as “sleeper plates” in our series. Thirteen plates (52%) maintained the achieved correction after a mean of 21 months (range: 4 to 39 mo), 9 plates (36%) required screw reinsertion due to rebound after a mean of 22 months (range: 12 to 48 mo) from screw removal, and 4 plates (16%) showed tethering with undesired continuation of guided growth after a mean of 14 months (range: 7 to 22 mo) from screw removal. Younger patients (<8 y at time of plate insertion) had higher rates of rebound and tethering (P=0.0112, Fisher exact test). All tethering occurred in titanium plates, none occurred in steel plates.

Conclusions:

The sleeper plate is an acceptable treatment strategy for coronal deformities around the knee, however, tethering and rebound may occur, especially in younger patients. Titanium plates may increase the risk of tethering, however, further long-term follow-up is needed as there were only 6 steel plates versus 19 titanium in this study. We stress the importance of close postoperative follow-up to identify signs of tethering and rebound early to prevent over-correction.

Level of Evidence:

Level IV—retrospective case study.
Drain Removal Time in Pre-pectoral versus Dual Plane Prosthetic Breast Reconstruction following Nipple-sparing Mastectomy
Authors: Moriarty Hannah K. , Baker Nusaiba F. , Hart Alexandra M. , Carlson Grant W. , Losken Albert
Published: May 2022

Background:

Pre-pectoral prosthetic breast reconstruction following nipple-sparing mastectomy (NSM) has become a popular approach compared with the dual plane technique. Our objective was to determine if there was a difference in time to postoperative breast drain removal in direct-to-implant or tissue expander reconstruction following NSM when comparing pre-pectoral with dual plane technique.

Methods:

A total of 200 patients (335 breasts) received NSM followed by implant or expander reconstruction at our institution between the years 2009 and 2020. Direct-to-implant reconstruction had 113 pre-pectoral versus 67 dual plane, and tissue expander reconstruction had six pre-pectoral versus 149 dual plane. Our analysis included age at mastectomy, body mass index, history of preoperative breast radiation, and smoking history. Case complications included seroma or hematoma, breast or axillary infection requiring antibiotics or operative washout, device replacement due to extrusion or infection, skin necrosis, and capsular contracture. Statistical analysis was completed with Pearson chi-square test, Fisher exact test, and the two-sample T-test using IBM SPSS Statistics 24.0 (IBM Corp., Armonk, N.Y.).

Results:

The average time until breast drain removal in dual plane implant patients was significantly less than in pre-pectoral implant patients (9.42 versus 14.01 days). The average time until breast drain removal in dual plane expander patients was significantly less than in pre-pectoral expander patients (11.47 versus 20.30 days).

Conclusion:

In both implant and expander reconstruction following NSM, patients receiving dual plane device placement had a shorter postoperative time until breast drain removal when compared with patients receiving pre-pectoral device placement.
Diffuse Type Neurofibroma of the Forearm
Authors: Al Lahham Salim , Aljassem Ghanem , Omari Rand Y. , Alyazji Zaki , Sada Ruba , Asnaf Ayman , Abuelgasim Mutaz
Published: May 2022

Nerve sheath tumors comprise 5% of soft tissue masses of the upper limb in adults. Neurofibromas are divided into three types: localized, diffuse, and plexi- form. The diffuse type is rare and is typically found in the head and neck region. We present a rare case of diffuse type neurofibroma found in the forearm, presented to our clinic as a slowly enlarging mass of the left forearm of 3 years duration. The lesion was suspicious in the magnetic resonance imaging, and biopsy revealed diffuse type neurofibroma. We opted for total excision of the lesion that was found to be not possible due to involvement of the major nerves. The final pathology report showed no malignancy. Nerve tumors of the upper limb can be either benign or malignant. Neurofibroma associated with neurofibromatosis has malignant potential. The diffuse type is rare, and it most commonly occurs in the head and neck region. It has a low malignant transformation rate. Magnetic resonance imaging is the diagnostic modality of choice; however, it can be inconclusive. Biopsy should be taken to confirm the diagnosis and plan for management. Our case was managed by near total excision in order to preserve the major forearm nerves because of high clinical suspicion.