bluuebunny/crossref_metadata_2025_split huggingface dataset:
108 Impacts of dam age and milk production on cow/calf profitability
Authors: Mulliniks Travis , Beard Joslyn , King Tasha 
Published: July 2020

Abstract
Cow herd profitability can be greatly influenced by reproductive success, average age of herd, and genetic potential within the environment. Productivity is influenced by cow age with calf weaning weight, increasing from 2 to 5 yr of age in dams. With that in mind, increasing average age of the cowherd has the potential to increase cow/calf profitability. Culling cows before 5 yr of age negatively impacts production efficiency due to decreased calf weaning weight in younger cows and subsequently, increase replacement rate and costs. Therefore, reproduction in young cattle is important to overall economic efficiency within the cow herd and a driving factor in longevity. Due to decreased reproduction and offspring performance, young females have previously been considered an economic liability. The effect of increased average cow age within the herd along with increased pregnancy rate of young cows has shown to increase production efficiency by decreasing replacement rates and adding greater production potential with increased calf weaning weights. In young beef cows, partitioning nutrients away from lactational demands allows for nutrients to be utilized for cow growth and reproduction. An increase in selection for milk production has resulted in beef cows undergoing greater nutritional stress during early lactation, which ultimately reduces cowherd reproduction and efficiency. Although a big emphasis is placed on output traits, economic value of reproduction is 5 times greater than growth or maternal output traits in beef cattle. In addition, the value of the added milk production may not fully be captured, due to extensive environments with limited nutrients. Even in environments with greater feed resources, selection for milk production may led to a decrease in reproduction, production efficiency, and cowherd retention rate.
Dispersion, communication, and alignment: an experimental study of the emergence of structure in combinatorial phonology
Authors: Roberts Gareth , Clark Robin 
Published: July 2020

AbstractLanguages exhibit structure at a number of levels, including at the level of phonology, the system of meaningless combinatorial units from which words are constructed. Phonological systems typically exhibit greater dispersion than would be expected by chance. Several theoretical models have been proposed to account for this, and a common theme is that such organization emerges as a result of the competing forces acting on production and perception. Fundamentally, this implies a cultural evolutionary explanation, by which emergent organization is an adaptive response to the pressures of communicative interaction. This process is hard to investigate empirically using natural-language data. We therefore designed an experimental task in which pairs of participants play a communicative game using a novel medium in which varying the position of one’s finger on a trackpad produced different colors. This task allowed us to manipulate the alignment of pressures acting on production and perception. Here we used it to investigate (1) whether above-chance levels of dispersion would emerge in the resulting systems, (2) whether dispersion would correlate with communicative success, and (3) how systems would differ if the pressures acting on perception were misaligned with pressures acting on production (and which would take precedence). We found that above-chance levels of dispersion emerged when pressures were aligned, but that the primary driver of communicative success was the alignment of production and perception pressures rather than dispersion itself. When they were misaligned, participants both found the task harder and (driven by perceptual demands) created systems with lower levels of dispersion.
The Galactic population and properties of young, highly energetic pulsars
Authors: Johnston Simon , Smith D A , Karastergiou A , Kramer M 
Published: July 2020

ABSTRACT
The population of young, non-recycled pulsars with spin-down energies $\dot{E} \gt 10^{35}$ erg s−1 is sampled predominantly at γ-ray and radio wavelengths. A total of 137 such pulsars are known, with partial overlap between the sources detectable in radio and γ-rays. We use a very small set of assumptions in an attempt to test whether the observed pulsar sample can be explained by a single underlying population of neutron stars. For radio emission we assume a canonical conal beam with a fixed emission height of 300 km across all spin periods and a luminosity law which depends on $\dot{E}^{0.25}$. For γ-ray emission we assume the outer-gap model and a luminosity law which depends on $\dot{E}^{0.5}$. We synthesize a population of fast-spinning pulsars with a birth rate of one per 100 yr. We find that this simple model can reproduce most characteristics of the observed population with two caveats. The first is a deficit of γ-ray pulsars at the highest $\dot{E}$ which we surmise to be an observational selection effect due to the difficulties of finding γ-ray pulsars in the presence of glitches without prior knowledge from radio frequencies. The second is a deficit of radio pulsars with interpulse emission, which may be related to radio emission physics. We discuss the implications of these findings.
New luminous blue variable candidates in the NGC 247 galaxy
Authors: Solovyeva Y , Vinokurov A , Sarkisyan A , Atapin K , Fabrika S , Valeev A F , Kniazev A , Sholukhova O , Maslennikova O 
Published: July 2020

ABSTRACT
We search for luminous blue variable (LBV) stars in galaxies outside the Local Group. Here we present a study of two bright Hα sources in the NGC 247 galaxy. Object j004703.27–204708.4 (MV = −9.08 ± 0.15 mag) shows the spectral lines typical for well-studied LBV stars: broad and bright emission lines of hydrogen and helium He i with P Cyg profiles, emission lines of iron Fe ii, silicon Si ii, nitrogen N ii and carbon C ii, forbidden iron [Fe ii] and nitrogen [N ii] lines. The variability of the object is ΔB = 0.74 ± 0.09 mag and ΔV = 0.88 ± 0.09 mag, which makes it a reliable LBV candidate. The star j004702.18–204739.93 (MV = −9.66 ± 0.23 mag) shows many emission lines of iron Fe ii, forbidden iron lines [Fe ii], bright hydrogen lines with broad wings, and also forbidden lines of oxygen [O i] and calcium [Ca ii] formed in the circumstellar matter. The study of the light curve of this star did not reveal significant variations in brightness (ΔV = 0.29 ± 0.09 mag). We obtained estimates of interstellar absorption, the photosphere temperature, as well as bolometric magnitudes $M_\text{bol}=-10.5^{+0.5}_{-0.4}$ and $M_\text{bol}=-10.8^{+0.5}_{-0.6}$, which correspond to bolometric luminosities $\log (L_\text{bol}/{\rm L}_{\odot })=6.11^{+0.20}_{-0.16}$ and $6.24^{+0.20}_{-0.25}$ for j004703.27–204708.4 and j004702.18–204739.93, respectively. Thus, the object j004703.27–204708.4 remains a reliable LBV candidate, while the object j004702.18–204739.93 can be classified as a B[e]-supergiant.
A chromosome map to unveil stellar populations with different magnesium abundances. The case of ω Centauri
Authors: Milone A P , Marino A F , Renzini A , Li C , Jang S , Lagioia E P , Tailo M , Cordoni G , Carlos M , Dondoglio E 
Published: July 2020

ABSTRACT
Historically, photometry has been largely used to identify stellar populations [multiple populations (MPs)] in globular clusters (GCs) by using diagrams that are based on colours and magnitudes that are mostly sensitive to stars with different metallicities or different abundances of helium, carbon, nitrogen, and oxygen. In particular, the pseudo-two-colour diagram called chromosome map (ChM), allowed the identification and the characterization of MPs in about 70 GCs by using appropriate filters of the Hubble Space Telescope (HST) that are sensitive to the stellar content of He, C, N, O, and Fe.
We use here high precision HST photometry from F275W, F280N, F343N, F373N, and F814W images of ω Centauri to investigate its MPs. We introduce a new ChM whose abscissa and ordinate are mostly sensitive to stellar populations with different magnesium and nitrogen, respectively, in monometallic GCs. This ChM is effective in disentangling the MPs based on their Mg chemical abundances, allowing us to explore, for the first time, possible relations between the production of these elemental species for large samples of stars in GCs.
By comparing the colours of the distinct stellar populations with the colours obtained from appropriate synthetic spectra we provide ‘photometric-like’ estimates of the chemical composition of each population. Our results show that, in addition to first-generation (1G) stars, the metal-poor population of ω Cen hosts four groups of second-generation stars with different [N/Fe], namely, 2GA–D. 2GA stars share nearly the same [Mg/Fe] as the 1G, whereas 2GB, 2GC, and 2GD are Mg depleted by ∼0.15, ∼0.25, and ∼0.45 dex, respectively. We provide evidence that the metal-intermediate populations host stars with depleted [Mg/Fe].
Constraining early-time dust formation in core-collapse supernovae
Authors: Priestley F D , Bevan A , Barlow M J , De Looze I 
Published: July 2020

ABSTRACT
There is currently a severe discrepancy between theoretical models of dust formation in core-collapse supernovae (CCSNe), which predict $\gtrsim 0.01 \, {\rm M}_\odot$ of ejecta dust forming within ∼1000 d, and observations at these epochs, which infer much lower masses. We demonstrate that, in the optically thin case, these low dust masses are robust despite significant observational and model uncertainties. For a sample of 11 well-observed CCSNe, no plausible model reaches carbon dust masses above $10^{-4} \, {\rm M}_\odot$, or silicate masses above $\sim 10^{-3} \, {\rm M}_\odot$. Optically thick models can accommodate larger dust masses, but the dust must be clumped and have a low (&lt;0.1) covering fraction to avoid conflict with data at optical wavelengths. These values are insufficient to reproduce the observed infrared fluxes, and the required covering fraction varies not only between SNe but between epochs for the same object. The difficulty in reconciling large dust masses with early-time observations of CCSNe, combined with well-established detections of comparably large dust masses in supernova remnants, suggests that a mechanism for late-time dust formation is necessary.
Formation of counter-rotating stars during gas-rich disc–disc mergers
Authors: Martel Hugo , Richard Simon 
Published: July 2020

ABSTRACT
We present a new scenario for the origin of the counter-rotating stars in disc galaxies, defined as stars that have a negative tangential velocity. This scenario involves a merger between two gas-rich disc galaxies that have comparable masses, are nearly coplanar, and are rotating in the same direction. The merger results in an intense starburst, during which a significant fraction of the gas is converted to stars. The system then settles into an equilibrium configuration consisting of a thick disc and a bulge partly supported by velocity dispersion and a thin disc supported by rotation. Star formation proceeds until most of the gas supply is exhausted. Stars formed during the starburst have tangential velocities ranging from $-600$ to $600\, {\rm km\, s^{-1}}$. Stars formed afterward in the thick disc and bulge have high eccentricities and low tangential velocities, typically in the range $-100$ to $100\, {\rm km\, s^{-1}}$, while stars formed in the thin disc have large, positive velocities. All fast, counter-rotating stars ($V\lt -200\, {\rm km\, s^{-1}}$) are old, metal-poor, with very low dispersion in ages and metallicities. By contrast, fast, corotating stars ($V\gt 200\, {\rm km\, s^{-1}}$) have a wide range of ages and metallicities. The average abundances ratios $\rm [O/H]$ and [Fe/H] for fast, corotating stars typically exceed the corresponding ratios for fast, counter-rotating stars by $0.1-0.4\,\mathrm{ dex}$, while the dispersion in the values of NFe/NH are larger by factors between 2 and 14. This provides an observational signature of major, gas-rich mergers at high redshift.
Extinct radio pulsars as a source of subrelativistic positrons
Authors: Istomin Ya N , Chernyshov D O , Sob’yanin D N 
Published: July 2020

ABSTRACT
Extinct radio pulsars, in which stationary, self-sustaining generation of a relativistic electron–positron plasma becomes impossible when rotation brakes down, can be sources of a subrelativistic flux of positrons and electrons. We assume that the observed excess of positrons in the bulge and the disc of the Galaxy is associated with these old neutron stars. The production of pairs in their magnetospheres occurs due to one-photon absorption of gamma quanta of the Galactic and extragalactic backgrounds. The cascade process of plasma production leads to the flux of positrons escaping from the open magnetosphere ≃3 × 1034 s−1. The total flux of positrons from all old Galactic neutron stars with rotational periods 1.5 &lt; P &lt; 35 s is ≃3 × 1043 s−1. The energy of positrons is less than ≃10 MeV. The estimated characteristics satisfy the requirements for the positron source responsible for the 511-keV Galactic annihilation line.
Outcomes and Spectrum of Major Neurovascular Events Among COVID-19 Patients: A 3-Center Experience
Authors: Taylor Blake E S , Khandelwal Priyank , Rallo Michael S , Patel Purvee , Smith Lindsey , Sun Hai , Nanda Anil , Singla Amit , Roychowdhury Sudipta , Cheng Roger C , Lee Kiwon , Gupta Gaurav , Johnson Stephen A 
Published: July 2020

ABSTRACT

BACKGROUND
Preliminary data suggest that Coronavirus Disease-2019 (COVID-19) is associated with hypercoagulability and neurovascular events, but data on outcomes is limited.

OBJECTIVE
To report the clinical course and outcomes of a case series of COVID-19 patients with a variety of cerebrovascular events.

METHODS
We performed a multicentric, retrospective chart review at our three academic tertiary care hospitals, and identified all COVID-19 patients with cerebrovascular events requiring neuro-intensive care and/or neurosurgical consultation.

RESULTS
We identified 26 patients between March 1 and May 24, 2020, of whom 12 (46%) died. The most common event was a large-vessel occlusion (LVO) in 15 patients (58%), among whom 8 died (8/15, 53%). A total of 9 LVO patients underwent mechanical thrombectomy, of whom 5 died (5/9, 56%). A total of 7 patients (27%) presented with intracranial hemorrhage. Of the remaining patients, 2 had small-vessel occlusions, 1 had cerebral venous sinus thrombosis, and another had a vertebral artery dissection. Acute Respiratory Distress Syndrome occurred in 8 patients, of whom 7 died. Mortalities had a higher D-dimer on admission (mean 20 963 ng/mL) than survivors (mean 3172 ng/mL). Admission Glasgow Coma Scale (GCS) score was poor among mortalities (median 7), whereas survivors had a favorable GCS at presentation (median 14) and at discharge (median 14).

CONCLUSION
COVID-19 may be associated with hemorrhage as well as ischemia, and prognosis appears poorer than expected—particularly among LVO cases, where outcome remained poor despite mechanical thrombectomy. However, a favorable neurological condition on admission and lower D-dimer may indicate a better outcome.
Impact of Group Selection Silviculture on Timber Harvesting Productivity and Cost in Appalachian Hardwood Timber Stands
Authors: Shaffer Robert M. , Brummel Kenneth R. , Reisinger Thomas W. , Stokes Bryce J. 
Published: July 2020

Abstract
Group selection is a regeneration harvest method that is being promoted by the USDA Forest Service as an alternative to clearcutting. In a group selection cut, "groups" of trees are marked and harvested in small patches dispersed in a mosaic pattern throughout the timber stand. Group selection has the potential to increase harvesting cost as compared to traditional clearcutting. Three logging systems, a skyline yarder system, a feller-buncher/cable skidder system, and a chainsaw felling/cable skidder system were studied while logging group selection timber sales in the Jefferson National Forest in Virginia. Time study data on the felling and skidding functions were recorded, as well as weekly production and cost data for each operation. Historic clearcutting production was obtained from the study loggers' records for comparison purposes. Group selection unit costs were $39.72, $14.13, and $15.33 per ton for the three systems, respectively. The study systems experienced decreases in production ranging front 17% to 52%. Most of the production decrease was due to an excessive amount of unproductive time directly resulting from the impact of the small, dispersed, multiple-harvest areas on the loggers' normal operating procedure and work flow. North. J. Appl. For. 10(4): 170-174.
2295. Clinical Characteristics of Achromobacter Xylosoxidans Infections in a Korean Teaching Hospital
Authors: Hong Hyo-Lim , Ho Lee Kang 
Published: July 2020

Abstract

Background
Achromobacter species are non-fermentous Gram-negative bacilli that are primarily found in contaminated soil or water, but is rare in human. Although their low virulence, Achromobacter xylosoxidans is considered one of the emerging nosocomial agents in immunocompromised patients, including those with hematologic malignancy, diabetes, and renal failure. This organisms can cause pneumonia, catheter-related blood stream infection, urinary tract infection, and meningitis. We investigated the clinical manifestations and outcomes associated with A. xylosoxidans infection in a mid-sized community-based hospital in Korea.

Methods
We retrospectively analyzed all consecutive episodes of A. xylosoxidans in a mid-sized community-based hospital from October 2015 to April 2019.

Results
A total 181 clinical isolates of A. xylosoxidans were obtained from 123 patients. Of these, 117 (95%) had nosocomial infection that mostly received previous antibiotic therapy. A. xylosoxidans was isolated from respiratory tract (68%, 84/123), peritoneal fluid (11%, 13/123), urine (8%, 10/123) and blood (6%, 7/123). Seven cases of A. xylosoxidans bacteremia was associated with intravenous catheter sepsis. Seventy-eight cases (63%) had polymicrobial infection; P. aeruginosa (n = 21) was most commonly coisolates organisms, followed by S. maltophilia (n = 20) and methicillin-resistant S. aureus (n = 15). The main underlying diseases were neurologic disease (41%), diabetes mellitus (36%), and solid cancer (25%). Of these, 53 patients (43%) were categorized as in an immunocompromised state. The in-hospital mortality rate was 23%. Based on multivariate analysis, neurologic disease (hazard ratio [HR]: 1.23, 95% confidence interval [CI]: 0.08–0.67; P = 0.007) and the age-adjusted Charlson comorbidity score (HR: 1.31% CI: 1.038–1.65; P = 0.02) were associated with increased mortality.

Conclusion
We concludes that, though rare, A. xylosoxidans could be pathogenic in immunocompromised patients who are in hospital. A. xylosoxidans can cause nosocomial infection and bacteremia is mostly originating from intravenous catheter. The potential impact on the clinical outcome, further investigations are required to delineate the role of A. xylosoxidans.

Disclosures
All authors: No reported disclosures.
720. Efficacy of Fosfomycin for Injection (FOS) vs. Piperacillin–Tazobactam (PIP-TAZ) in Adults with Complicated Urinary Tract Infection (cUTI) and Acute Pyelonephritis (AP): ZEUS Study Outcomes in Patients With Reduced Study Drug Susceptibility
Authors: Kaye Keith S , Das Anita F , Eckburg Paul B , Gelone Steven P , Schranz Jennifer , Ellis-Grosse Evelyn J 
Published: July 2020

Abstract

Background
FOS is being pursued for US registration in cUTI/AP. Safety and efficacy of FOS vs. PIP-TAZ were demonstrated in the noninferiority ZEUS trial in hospitalized patients with cUTI/AP. Although FOS resistance has been observed in several in vitro studies, resistance rates in clinical settings have remained relatively stable despite &gt;40 years of clinical use of FOS outside of the United States. Here we report outcomes in patients who developed reduced susceptibility to study drug (FOS or PIP-TAZ) after enrollment in ZEUS.

Methods
Patients received IV FOS 6g q8h or PIP-TAZ 4.5g q8h for 7 days (no oral switch allowed). The primary endpoint was overall success (clinical cure + microbiologic eradication) in microbiologic modified intent-to-treat (m-MITT) population at test-of-cure (TOC; Day 19–21). Reduced susceptibility to FOS or PIP-TAZ was defined as a ≥4-fold increase from baseline in minimum inhibitory concentration (MIC) at Day 5, end of treatment (EOT; Day 7–8), TOC, or late follow-up (LFU; Day 26 ± 2). Microbiologic eradication/persistence of baseline and postbaseline pathogens was confirmed post hoc by pulsed-field gel electrophoresis (PFGE).

Results
In all m-MITT patients, overall success/clinical cure/microbiologic eradication rates (with PFGE) at TOC were 69.0/90.8/70.7% (FOS) and 57.3/91.6/60.1% (PIP-TAZ). Reduced study drug susceptibility was identified in 7/184 (3.8%) FOS and 8/178 (4.5%) PIP-TAZ patients; all had monomicrobial infections (Table 1). Of these patients, almost all were aged ≥50 years (93%), male (73%), white (100%), and had a screening diagnosis of cUTI (93%). At TOC, 7/7 FOS patients and 7/8 PIP-TAZ patients had microbiologic persistence but all patients were clinical cures; these responses were all sustained through LFU (Table 1).

Conclusion
In the ZEUS study, few patients had urine isolates with reduced postbaseline susceptibility to either FOS or PIP-TAZ. No trend was observed in isolate species associated with decreased susceptibility to FOS or PIP-TAZ, including various Enterobacteriaceae species and Pseudomonas aeruginosa. Despite microbiologic persistence at TOC in a small number of patients, all of these patients were clinical cures at TOC and sustained cures at LFU.

Disclosures
All authors: No reported disclosures.
0866 Does Obstructive Sleep Apnea Mediate the Relationship Between Post-Traumatic Stress Disorder and Low Back Pain in Veterans?
Authors: Taylor Kenneth A , Schwartz Skai W , Sebastião Yuri V , Anderson William McD , Foulis Phillip R 
Published: July 2020

Abstract

Introduction
Low back pain (LBP) is a common complaint among veterans, leading to notable limits in function, quality of life, and an increase in healthcare cost. The incidence and prevalence of LBP have been increasing in the veterans over the past several years. Obstructive sleep apnea (OSA) has been shown to be associated with LBP and there are notable associations among post-traumatic stress disorder (PTSD), OSA and LBP in this population.

Methods
A random sample of veterans stratified by quarter was taken between 2007 and 2011 (index date), collecting records from 2006 to 2016. Veterans were excluded if they had a prevalent case of LBP, and/or OSA in the year of or year before to their index date (index period), or PTSD, OSA and/or LBP prior to the index period. Associations among the PTSD, LBP, and OSA were calculated using SAS PROC LOGISTIC. SAS PROC PHREG was used to calculate hazard ratios (HR) for mediation analysis and the percent of 4-year LBP risk explained by OSA in those with PTSD.

Results
PTSD predicted LBP diagnosis (OR 1.52 [95% CI: 1.27, 1.83]) and OSA diagnosis (OR 2.06 [1.48, 2.88]). Additionally, OSA diagnosis was predictive of LBP diagnosis (OR 8.99 [95% CI: 7.07, 11.35]). The HR for the effect of PTSD on the risk LBP diagnosis was 1.47 (95% CI: 1.25, 1.74) without adjustment for OSA. The HR for the effect of PTSD on the risk LBP diagnosis adjusted for the mediator was 1.35 (95% CI: 1.15, 1.60). The resulting percent of excess LBP risk explained by OSA is 25.5% (95% CI: 19.6%,31.1%). All analyses were adjusted for potential confounders.

Conclusion
OSA may mediate a significant amount of the risk of LBP diagnosis in veterans with PTSD. Prevention of OSA among veterans with PTSD may significantly reduce the risk of future LBP in veterans with PTSD.

Support (If Any)
This material is the result of work supported with resources and the use of facilities at the James A. Haley Veterans’ Hospital.