bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Economic Thresholds for Insecticide Applications Against Agricultural Pests: Importance of Pest and Natural Enemy Migration
Authors: Keasar Tamar , Wajnberg Eric , Heimpel George , Hardy Ian C W , Harpaz Liora Shaltiel , Gottlieb Daphna , van Nouhuys Saskya 
Published: February 2023

Abstract
In Integrated Pest Management programs, insecticides are applied to agricultural crops when pest densities exceed a predetermined economic threshold. Under conditions of high natural enemy density, however, the economic threshold can be increased, allowing for fewer insecticide applications. These adjustments, called ‘dynamic thresholds’, allow farmers to exploit existing biological control interactions without economic loss. Further, the ability of natural enemies to disperse from, and subsequently immigrate into, insecticide-sprayed areas can affect their biological control potential. We develop a theoretical approach to incorporate both pest and natural enemy movement across field borders into dynamic thresholds and explore how these affect insecticide applications and farmer incomes. Our model follows a pest and its specialist natural enemy over one growing season. An insecticide that targets the pest also induces mortality of the natural enemy, both via direct toxicity and reduced resource pest densities. Pest and natural enemy populations recover after spraying through within-field reproduction and by immigration from neighboring unsprayed areas. The number of insecticide applications and per-season farmer revenues are calculated for economic thresholds that are either fixed (ignoring natural enemy densities) or dynamic (incorporating them). The model predicts that using dynamic thresholds always leads to reduced insecticide application. The benefit of dynamic thresholds in reducing insecticide use is highest when natural enemies rapidly recolonize sprayed areas, and when insecticide efficacy is low. We discuss real-life situations in which monitoring of natural enemies would substantially reduce insecticide use and other scenarios where the presence of beneficial organisms may lead to threshold modifications.
A delayed benign anastomotic stricture after anterior resection for sigmoid adenocarcinoma with concomitant collagenous colitis
Authors: Wallace Lauren , Gallagher James 
Published: February 2023

AbstractBenign anastomotic strictures most commonly occur within 3–12 months after anterior resection (AR) with chronic symptoms amenable to endoscopic treatment. This case describes an acute large bowel obstruction secondary to a severe delayed benign anastomotic stricture in a 74-year-old female who had previously underwent a laparoscopic AR for sigmoid adenocarcinoma 3 years prior. The pathophysiology of benign anastomotic strictures remains poorly understood. This case was likely multifactorial. Potential contributing factors include anastomotic ischaemia and concomitant collagenous colitis, with inflammation leading to fibrosis and stricture development. Surgical techniques to optimize anastomotic vascularity are important to consider, particularly in older patients with multiple co-morbidities.
VA Outreach Is an Essential Area for Improving Veterans’ Health Care Accessibility
Authors: Stryczek Krysttel C , Honsberger Mark , Ball Sherry L , Barnard Juliana G , Young Jessica P , Felker Bradford , Au David H , Ho P Michael , Kirsh Susan R , Sayre George G 
Published: February 2023

ABSTRACT

Introduction
The Veterans Health Administration (VHA) is tasked with providing access to health care to veterans of military service. However, many eligible veterans have either not yet enrolled or underutilized VHA services. Further study of barriers to access before veterans enroll in VHA care is necessary to understand how to address this issue. The ChooseVA (née MyVA Access) initiative aims to achieve this mission to improve veterans’ health care access. Although veteran outreach was not specifically addressed by the initiative, it is a critical component of improving veterans’ access to health care. Findings from this multisite evaluation of ChooseVA implementation describe sites’ efforts to improve VHA outreach and veterans’ experiences with access.

Materials and Methods
This quality improvement evaluation employed a multi-method qualitative methodology, including 127 semi-structured interviews and 81 focus groups with VHA providers and staff (“VHA staff”) completed during 21 VHA medical center facility site visits between July and November 2017 and 48 telephone interviews with veterans completed between May and October 2018. Interviews and focus groups were transcribed and analyzed using deductive and inductive analysis to capture challenges and strategies to improve VHA health care access (VHA staff data), experiences with access to care (veteran data), barriers and facilitators to care (staff and veteran data), contextual factors, and emerging categories and themes. We developed focused themes describing perceived challenges, descriptions of VHA staff efforts to improve veteran outreach, and veterans’ experiences with accessing VHA health care.

Results
VHA staff and veteran respondents reported a lack of veteran awareness of eligibility for VHA services. Veterans reported limited understanding of the range of services offered. This awareness gap served as a barrier to veterans’ ability to successfully access VHA health care services. Veterans described this awareness gap as contributing to delayed VHA enrollment and delayed or underutilized health care benefits and services. Staff focused on community outreach and engaging veterans for VHA enrollment as part of their efforts to implement the ChooseVA access initiative. Staff and veteran respondents agreed that outreach efforts were helpful for engaging veterans and facilitating access.

Conclusions
Although efforts across VHA programs informed veterans about VHA services, our results suggest that both VHA staff and veterans agreed that missed opportunities exist. Gaps include veterans’ lack of awareness or understanding of VHA benefits for which they qualify for. This can result in delayed access to care which may negatively impact veterans, including those separating from the military and vulnerable populations such as veterans who experience pregnancy or homelessness.
A survey for variable young stars with small telescopes – VII. Spot properties on YSOs in IC 5070
Authors: Herbert Carys , Froebrich Dirk , Scholz Aleks 
Published: February 2023

ABSTRACTWe present measurements of spot properties on 31 young stellar objects, based on multiband data from the HOYS (Hunting Outbursting Young Stars) project. On average the analysis for each object is based on 270 data points during 80 d in at least three bands. All the young low-mass stars in our sample show periodic photometric variations. We determine spot temperatures and coverage by comparing the measured photometric amplitudes in optical bands with simulated amplitudes based on atmosphere models, including a complete error propagation. 21 objects in our sample feature cool spots, with spot temperatures 500–2500 K below the stellar effective temperature (Teff), and a coverage of 0.05–0.4. Six more have hot spots, with temperatures up to 3000 K above Teff and coverage below 0.15. The remaining four stars have ambiguous solutions or are AA Tau-type contaminants. All of the stars with large spots (i.e. high coverage &gt;0.1) are relatively cool with Teff &lt; 4500 K, which could be a result of having deeper convection zones. Apart from that, spot properties show no significant trends with rotation period, infrared excess, or stellar properties. Most notably, we find hot spots in stars that do not show K − W2 infrared excess, indicating the possibility of accretion across an inner disc cavity or the presence of plage.
The cosmic ray ionization and γ-ray budgets of star-forming galaxies
Authors: Krumholz Mark R , Crocker Roland M , Offner Stella S R 
Published: February 2023

ABSTRACT
Cosmic rays in star-forming galaxies are a dominant source of both diffuse γ-ray emission and ionization in gas too deeply shielded for photons to penetrate. Though the cosmic rays responsible for γ-rays and ionization are of different energies, they are produced by the same star formation-driven sources, and thus galaxies’ star formation rates, γ-ray luminosities, and ionization rates should all be linked. In this paper, we use up-to-date cross-section data to determine this relationship, finding that cosmic rays in a galaxy of star formation rate $\dot{M}_*$ and gas depletion time tdep produce a maximum primary ionization rate ζ ≈ 1 × 10−16(tdep/Gyr)−1 s−1 and a maximum γ-ray luminosity $L_\gamma \approx 4\times 10^{39} (\dot{M}_*/\mathrm{M}_\odot \mbox{ yr}^{-1})$ erg s−1 in the 0.1–100 GeV band. These budgets imply either that the ionization rates measured in Milky Way molecular clouds include a significant contribution from local sources that elevate them above the Galactic mean, or that CR-driven ionization in the Milky Way is enhanced by sources not linked directly to star formation. Our results also imply that ionization rates in starburst systems are only moderately enhanced compared to those in the Milky Way. Finally, we point out that measurements of γ-ray luminosities can be used to place constraints on galactic ionization budgets in starburst galaxies that are nearly free of systematic uncertainties on the details of cosmic ray acceleration.
Study of maximum electron energy of sub-PeV pulsar wind nebulae by multiwavelength modelling
Authors: Joshi Jagdish C , Tanaka Shuta J , Miranda Luis Salvador , Razzaque Soebur 
Published: February 2023

ABSTRACTRecently, the Large High Altitude Air Shower Observatory (LHAASO) reported the discovery of 12 ultrahigh-energy (UHE; ε ≥ 100 TeV) gamma-ray sources located in the Galactic plane. A few of these UHE gamma-ray emitting regions are in spatial coincidence with pulsar wind nebulae (PWNe). We consider a sample of five sources: two of them are LHAASO sources (LHAASO J1908+0621 and LHAASO J2226+6057) and the remaining three are GeV–TeV gamma-ray emitters. In addition, X-rays, radio observations, or upper limits are also available for these objects. We study multiwavelength radiation from these sources by considering a PWN origin, where the emission is powered by spin-down luminosity of the associated pulsars. In this Leptonic emission model, the electron population is calculated at different times under the radiative (synchrotron and inverse-Compton) and adiabatic cooling. We also include the onset of the reverberation phase for the PWN, by assuming radially symmetric expansion. However, in this work, we find that multiwavelength emission can be interpreted before the onset of this phase. The maximum energy of the electrons based on the spectral fit is found to be above 0.1 PeV and close to 1 PeV. For LHAASO J2226+6057, using its observations in radio to UHE gamma-rays, we find that UHE gamma-rays can be interpreted using electrons with maximum energy of 1 PeV. We estimate the upper limits on the minimum Lorentz factor of the electrons and it also infers the minimum value of the pair-multiplicity of charged pairs.
Cosmic-ray-driven galactic winds: transport modes of cosmic rays and Alfvén-wave dark regions
Authors: Thomas T , Pfrommer C , Pakmor R 
Published: February 2023

ABSTRACTFeedback mediated by cosmic rays (CRs) is an important process in galaxy formation. Because CRs are long-lived and because they are transported along the magnetic field lines independently of any gas flow, they can efficiently distribute their feedback energy within the galaxy. We present an in-depth investigation of (i) how CRs launch galactic winds from a disc that is forming in a $10^{11} \, \rm {M}_\odot$ halo and (ii) the state of CR transport inside the galactic wind. To this end, we use the arepo moving-mesh code and model CR transport with the two-moment description of CR hydrodynamics. This model includes the CR interaction with the gyroresonant Alfvén waves that enable us to self-consistently calculate the CR diffusion coefficient and CR transport speeds based on coarse-grained models for plasma physical effects. This delivers insight into key questions such as whether the effective CR transport is streaming-like or diffusive-like, how the CR diffusion coefficient and transport speed change inside the circumgalactic medium, and to what degree the two-moment approximation is needed to faithfully capture these effects. We find that the CR-diffusion coefficient reaches a steady state in most environments with the notable exception of our newly discovered Alfvén-wave dark regions where the toroidal wind magnetic field is nearly perpendicular to the CR pressure gradient so that CRs are unable to excite the gyroresonant Alfvén waves. However, CR transport itself cannot reach a steady state and is not well described by either the CR streaming paradigm, the CR diffusion paradigm, or a combination of both.
Linking the interiors and surfaces of magnetic stars
Authors: Fuller Jim , Mathis Stéphane 
Published: February 2023

ABSTRACTStrong magnetic fields are observed in a substantial fraction of upper main sequence stars and white dwarfs. Many such stars are observed to exhibit photometric modulations as the magnetic poles rotate in and out of view, which could be a consequence of magnetic perturbations to the star’s thermal structure. The magnetic pressure is typically larger than the gas pressure at the star’s photosphere, but much smaller than the gas pressure in the star’s interior, so the expected surface flux perturbations are not clear. We compute magnetically perturbed stellar structures of young $3 \, \mathrm{M}_\odot$ stars that are in both hydrostatic and thermal equilibrium, and which contain both poloidal and toroidal components of a dipolar magnetic field as expected for stable fossil fields. This provides semi-analytical models of such fields in baroclinic stably stratified regions. The star’s internal pressure, temperature, and flux perturbations can have a range of magnitudes, though we argue the most likely configurations exhibit flux perturbations much smaller than the ratio of surface magnetic pressure to surface gas pressure, but much larger than the ratio of surface magnetic pressure to central gas pressure. The magnetic pole is hotter than the equator in our models, but a cooler magnetic pole is possible depending on the magnetic field configuration. The expected flux variations for observed field strengths are δL/L ≲ 10−6, much smaller than those observed in magnetic stars, suggesting that observed perturbations stem from changes to the emergent spectrum rather than changes to the bolometric flux.
Spectral shapes of the Ly α emission from galaxies – II. The influence of stellar properties and nebular conditions on the emergent Ly α profiles
Authors: Hayes Matthew J , Runnholm Axel , Scarlata Claudia , Gronke Max , Rivera-Thorsen T Emil 
Published: February 2023

ABSTRACTWe demonstrate how the stellar and nebular conditions in star-forming galaxies modulate the emission and spectral profile of H i Ly α emission line. We examine the net Ly α output, kinematics, and in particular emission of blueshifted Ly α radiation, using spectroscopy from with the Cosmic Origins Spectrograph on Hubble Space Telescope (HST), giving a sample of 87 galaxies at redshift z = 0.05−0.44. We contrast the Ly α spectral measurements with properties of the ionized gas (from optical spectra) and stars (from stellar modelling). We demonstrate correlations of unprecedented strength between the Ly α escape fraction (and equivalent width) and the ionization parameter (p ≈ 10−15). The relative contribution of blueshifted emission to the total Ly α also increases from ≈0 to ≈40 per cent over the range of O32 ratios (p ≈ 10−6). We also find particularly strong correlations with estimators of stellar age and nebular abundance, and weaker correlations regarding thermodynamic variables. Low ionization stage absorption lines suggest the Ly α emission and line profile are predominantly governed by the column of absorbing gas near zero velocity. Simultaneous multiparametric analysis over many variables shows we can predict 80 per cent of the variance on Ly α luminosity, and ∼50 per cent on the EW. We determine the most crucial predictive variables, finding that for tracers of the ionization state and H β luminosity dominate the luminosity prediction whereas the Ly α EW is best predicted by H β EW and the H α/H β ratio. We discuss our results with reference to high-redshift observations, focussing upon the use of Ly α to probe the nebular conditions in high-z galaxies and cosmic reionization.
Prediction for the amplitude and second maximum of Solar Cycle 25 and a comparison of the predictions based on strength of polar magnetic field and low-latitude sunspot area
Authors: Javaraiah J 
Published: February 2023

ABSTRACTThe maximum of a solar cycle contains two or more peaks, known as Gnevyshev peaks. Studies of this property of solar cycles may help in better understanding the solar dynamo mechanism. We analysed the 13-month smoothed monthly mean Version-2 international sunspot number (SN) during the period 1874–2017 and found that there exists a good correlation between the amplitude (value of the main and highest peak) and the value of the second maximum (value of the second highest peak) during the maximum of a solar cycle. Using this relationship and the earlier predicted value 86 ± 18 (92 ± 11) of the amplitude of Solar Cycle 25, here we predict a value 73 ± 15 (79 ± 15) for the second maximum of Solar Cycle 25. The ratio of the predicted second maximum to the amplitude is found to be 0.85, almost the same as that of Solar Cycle 24. The least-square cosine fits to the values of the peaks that occurred first and second during the maxima of Solar Cycles 12–24 suggest that in Solar Cycle 25 the second maximum would occur before the main maximum, the same as in Solar Cycle 24. However, these fits suggest ≈106 and ≈119 for the second maximum and the amplitude of Solar Cycle 25, respectively. Earlier, we analysed the combined Greenwich and Debrecen sunspot-group data during 1874–2017 and predicted the amplitude of Solar Cycle 25 from the activity just after the maximum of Solar Cycle 24 in the equatorial latitudes of the Sun’s Southern hemisphere. Here, from the hindsight of the results we found the earlier prediction is reasonably reliable. We analysed the polar-fields data measured in Wilcox Observatory during Solar Cycles 20–24 and obtained a value 125 ± 7 for the amplitude of Solar Cycle 25. This is slightly larger – whereas the value ≈86 (≈92) predicted from the activity in the equatorial latitudes is slightly smaller – than the observed amplitude of Solar Cycle 24. This difference is discussed briefly.
How the existence of unstable neutral media restricts the aspect ratio of cold neutral media?
Authors: Ho Ka Wai , Yuen Ka Ho , Lazarian Alex 
Published: February 2023

ABSTRACT
The ubiquity of very thin and lengthy cold neutral medium (CNM) has been reported by multiple authors in the H i community. Yet, the reason of how the CNM can be so long and lengthy is still in debate. In this paper, we recognize a new type of instability due to the attractive nature of the pressure force in the unstable phase. We provide a new estimation of the average CNM filament aspect ratio with the consideration of force balances at the phase boundary, which is roughly 5–20 in common CNM environment. We show that most of the cold filaments are less filamentary than what usually predicted via MHD turbulence theory or inferred from observations: The average length of CNM filament is roughly 1/2 of that in isothermal MHD turbulence with similar turbulence conditions. This suggests that the ‘cold filaments’ that are identified in observations might not be in pressure equilibrium or generated via other mechanisms.
High-energy neutrino emission from magnetized jets of rapidly rotating protomagnetars
Authors: Bhattacharya Mukul , Carpio Jose A , Murase Kohta , Horiuchi Shunsaku 
Published: February 2023

ABSTRACT
Relativistic jets originating from protomagnetar central engines can lead to long duration gamma-ray bursts (GRBs) and are considered potential sources of ultra-high-energy cosmic rays and secondary neutrinos. We explore the propagation of such jets through a broad range of progenitors, from stars which have shed their envelopes to supergiants which have not. We use a semi-analytical spin-down model for the strongly magnetized and rapidly rotating protoneutron star (PNS) to investigate the role of central engine properties such as the surface dipole field strength, initial rotation period, and jet opening angle on the interactions and dynamical evolution of the jet-cocoon system. With this model, we determine the properties of the relativistic jet, the mildly relativistic cocoon, and the collimation shock in terms of system parameters such as the time-dependent jet luminosity, injection angle, and density profile of the stellar medium. We also analyse the criteria for a successful jet breakout, the maximum energy that can be deposited into the cocoon by the relativistic jet, and structural stability of the magnetized outflow relative to local instabilities. Lastly, we compute the high-energy neutrino emission as these magnetized outflows burrow through their progenitors. Precursor neutrinos from successful GRB jets are unlikely to be detected by IceCube, which is consistent with the results of previous works. On the other hand, we find that high-energy neutrinos may be produced for extended progenitors like blue and red supergiants, and we estimate the detectability of neutrinos with next generation detectors such as IceCube-Gen2.
VINTERGATAN-GM: The cosmological imprints of early mergers on Milky-Way-mass galaxies
Authors: Rey Martin P , Agertz Oscar , Starkenburg Tjitske K , Renaud Florent , Joshi Gandhali D , Pontzen Andrew , Martin Nicolas F , Feuillet Diane K , Read Justin I 
Published: February 2023

ABSTRACTWe present a new suite of cosmological zoom-in hydrodynamical ($\approx 20\, \mathrm{pc}$ spatial resolution) simulations of Milky-Way mass galaxies to study how a varying mass ratio for a Gaia-Sausage-Enceladus (GSE) progenitor impacts the z = 0 chemodynamics of halo stars. Using the genetic modification approach, we create five cosmological histories for a Milky-Way-mass dark matter halo ($M_{200}\approx 10^{12} \, \mbox{M}_\mathrm{\odot }$), incrementally increasing the stellar mass ratio of a z ≈ 2 merger from 1:25 to 1:2, while fixing the galaxy’s final dynamical, stellar mass, and large-scale environment. We find markedly different morphologies at z = 0 following this change in early history, with a growing merger resulting in increasingly compact and bulge-dominated galaxies. Despite this structural diversity, all galaxies show a radially biased population of inner halo stars like the Milky-Way’s GSE which, surprisingly, has a similar magnitude, age, $\rm [Fe/H]$, and $\rm [\alpha /Fe]$ distribution whether the z ≈ 2 merger is more minor or major. This arises because a smaller ex-situ population at z ≈ 2 is compensated by a larger population formed in an earlier merger-driven starburst whose contribution to the GES can grow dynamically over time, and with both populations strongly overlapping in the $\rm [Fe/H]-\rm [\alpha /Fe]$ plane. Our study demonstrates that multiple high-redshift histories can lead to similar z = 0 chemodynamical features in the halo, highlighting the need for additional constraints to distinguish them, and the importance of considering the full spectrum of progenitors when interpreting z = 0 data to reconstruct our Galaxy’s past.