bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyses of ‘change scores’ do not estimate causal effects in observational data
Authors: Tennant Peter W G , Arnold Kellyn F , Ellison George T H , Gilthorpe Mark S 
Published: March 2021

Abstract

Background
In longitudinal data, it is common to create ‘change scores’ by subtracting measurements taken at baseline from those taken at follow-up, and then to analyse the resulting ‘change’ as the outcome variable. In observational data, this approach can produce misleading causal-effect estimates. The present article uses directed acyclic graphs (DAGs) and simple simulations to provide an accessible explanation for why change scores do not estimate causal effects in observational data.

Methods
Data were simulated to match three general scenarios in which the outcome variable at baseline was a (i) ‘competing exposure’ (i.e. a cause of the outcome that is neither caused by nor causes the exposure), (ii) confounder or (iii) mediator for the total causal effect of the exposure variable at baseline on the outcome variable at follow-up. Regression coefficients were compared between change-score analyses and the appropriate estimator(s) for the total and/or direct causal effect(s).

Results
Change-score analyses do not provide meaningful causal-effect estimates unless the baseline outcome variable is a ‘competing exposure’ for the effect of the exposure on the outcome at follow-up. Where the baseline outcome is a confounder or mediator, change-score analyses evaluate obscure estimands, which may diverge substantially in magnitude and direction from the total and direct causal effects.

Conclusion
Future observational studies that seek causal-effect estimates should avoid analysing change scores and adopt alternative analytical strategies.
Differences in organization of care are associated with mortality, severe complication and failure to rescue in emergency colon cancer surgery
Authors: Huijts Daniëlle D , Dekker Jan willem T , van bodegom-vos Leti , van groningen Julia T , Bastiaannet Esther , Marang-van de mheen Perla J 
Published: March 2021

Abstract

Background
Emergency colon cancer surgery is associated with increased mortality and complication risk, which can be due to differences in the organization of hospital care. This study aimed.

Objective
To explore which structural factors in the preoperative, perioperative and postoperative periods influence outcomes after emergency colon cancer surgery.

Methods
An observational study was performed in 30 Dutch hospitals. Medical records from 1738 patients operated in the period 2012 till 2015 were reviewed on the type of referral, intensive care unit (ICU) level, surgeon specialization and experience, duration of surgery and operating room time, blood loss, stay on specialized postoperative ward, complication occurrence, reintervention and day of surgery and linked to case-mix data available in the Dutch Colorectal Audit. Multivariate logistic regression analysis was used to estimate the influence of these factors on 30-day mortality, severe complication and failure to rescue (FTR), after adjustment for case-mix.

Results
Patients operated by a non-Gastro intestinal/oncology specialized surgeon have significantly increased mortality (Odds Ratio (OR) 2.28 [95% confidence interval (95% CI) 1.23–4.23]) and severe complication risk (OR 1.61 [95% CI 1.08–2.39]). Also, duration of stay in the operating room was significantly associated with increased risk on severe complication (OR 1.03 [95% CI 1.01–1.06]). Patients admitted to a non-specialized ward have significantly increased mortality (OR 2.25 [95% CI 1.46–3.47]) and FTR risk (OR 2.39 [95% CI 1.52–3.75]). A low ICU level (basic ICU) was associated with a lower severe complication risk (OR 0.72 [95% CI 0.52–1.00]). Surgery on Tuesday was associated with a higher mortality risk (OR 2.82 [95% CI 1.24–6.40]) and a severe complication risk (OR 1.77, [95% CI 1.19–2.65]).

Conclusion
This study identified a non-specialized surgeon and ward, operating room, time and day of surgery to be risk factors for worse outcomes in emergency colon cancer surgery.
Deep extragalactic visible legacy survey (DEVILS): stellar mass growth by morphological type since z = 1
Authors: Hashemizadeh Abdolhosein , Driver Simon P , Davies Luke J M , Robotham Aaron S G , Bellstedt Sabine , Windhorst Rogier A , Bremer Malcolm , Phillipps Steven , Jarvis Matt , Holwerda Benne W , Lagos Claudia del P , Koushan Soheil , Siudek Malgorzata , Maddox Natasha , Thorne Jessica E , Elahi Pascal 
Published: March 2021

ABSTRACT
Using high-resolution Hubble Space Telescope imaging data, we perform a visual morphological classification of ∼36 000 galaxies at z &lt; 1 in the deep extragalactic visible legacy survey/cosmological evolution survey region. As the main goal of this study, we derive the stellar mass function (SMF) and stellar mass density (SMD) sub-divided by morphological types. We find that visual morphological classification using optical imaging is increasingly difficult at z &gt; 1 as the fraction of irregular galaxies and merger systems (when observed at rest-frame UV/blue wavelengths) dramatically increases. We determine that roughly two-thirds of the total stellar mass of the Universe today was in place by z ∼ 1. Double-component galaxies dominate the SMD at all epochs and increase in their contribution to the stellar mass budget to the present day. Elliptical galaxies are the second most dominant morphological type and increase their SMD by ∼2.5 times, while by contrast, the pure-disc population significantly decreases by $\sim 85{{\ \rm per\ cent}}$. According to the evolution of both high- and low-mass ends of the SMF, we find that mergers and in situ evolution in discs are both present at z &lt; 1, and conclude that double-component galaxies are predominantly being built by the in situ evolution in discs (apparent as the growth of the low-mass end with time), while mergers are likely responsible for the growth of ellipticals (apparent as the increase of intermediate/high-mass end).
Vortex pinning in the superfluid core of relativistic neutron stars
Authors: Sourie Aurélien , Chamel Nicolas 
Published: March 2021

ABSTRACT
Our recent Newtonian treatment of the smooth-averaged mutual-friction force acting on the neutron superfluid and locally induced by the pinning of quantized neutron vortices to proton fluxoids in the outer core of superfluid neutron stars is here adapted to the general-relativistic framework. We show how the local non-relativistic motion of individual vortices can be matched to the global dynamics of the star using the fully 4D covariant Newtonian formalism of Carter & Chamel. We derive all the necessary dynamical equations for carrying out realistic simulations of superfluid rotating neutron stars in full general relativity, as required for the interpretation of pulsar frequency glitches. The role of vortex pinning on the global dynamics appears to be non-trivial.
OMC-1 dust polarization in ALMA Band 7: diagnosing grain alignment mechanisms in the vicinity of Orion Source I
Authors: Pattle Kate , Lai Shih-Ping , Wright Melvyn , Coudé Simon , Plambeck Richard , Hoang Thiem , Tang Ya-Wen , Bastien Pierre , Eswaraiah Chakali , Furuya Ray S , Hwang Jihye , Inutsuka Shu-ichiro , Kim Kee-Tae , Kirchschlager Florian , Kwon Woojin , Lee Chang Won , Liu Sheng-Yuan , Lyo Aran , Ohashi Nagayoshi , Rawlings Mark G , Tahani Mehrnoosh , Tamura Motohide , Soam Archana , Wang Jia-Wei , Ward-Thompson Derek 
Published: March 2021

ABSTRACT
We present ALMA Band 7 polarization observations of the OMC-1 region of the Orion molecular cloud. We find that the polarization pattern observed in the region is likely to have been significantly altered by the radiation field of the &gt;104 L⊙ high-mass protostar Orion Source I. In the protostar’s optically thick disc, polarization is likely to arise from dust self-scattering. In material to the south of Source I – previously identified as a region of ‘anomalous’ polarization emission – we observe a polarization geometry concentric around Source I. We demonstrate that Source I’s extreme luminosity may be sufficient to make the radiative precession time-scale shorter than the Larmor time-scale for moderately large grains ($\gt 0.005\!-\!0.1\, \mu$m), causing them to precess around the radiation anisotropy vector (k-RATs) rather than the magnetic field direction (B-RATs). This requires relatively unobscured emission from Source I, supporting the hypothesis that emission in this region arises from the cavity wall of the Source I outflow. This is one of the first times that evidence for k-RAT alignment has been found outside of a protostellar disc or AGB star envelope. Alternatively, the grains may remain aligned by B-RATs and trace gas infall on to the Main Ridge. Elsewhere, we largely find the magnetic field geometry to be radial around the BN/KL explosion centre, consistent with previous observations. However, in the Main Ridge, the magnetic field geometry appears to remain consistent with the larger-scale magnetic field, perhaps indicative of the ability of the dense Ridge to resist disruption by the BN/KL explosion.
Space observations of AA Doradus provide consistent mass determinations. New HW-Vir systems observed with TESS
Authors: Baran A S , Østensen R H , Heber U , Irrgang A , Sanjayan S , Telting J H , Reed M D , Ostrowski J 
Published: March 2021

ABSTRACT
We present an overview of eclipsing systems of the HW-Virginis (HW-Vir) type, based on space observations from the Transiting Exoplanet Survey Satellite (TESS) mission. We perform a detailed analysis of the properties of AA Doradus (AA Dor), which was monitored for almost a full year. This excellent time series data set permitted us to search for both stellar pulsations and eclipse timing variations. In addition, we used the high-precision trigonometric parallax from Gaia Early Data Release 3 to make an independent determination of the fundamental stellar parameters. No convincing pulsations were detected down to a limit of 76 parts per million; however, we detected one peak with false alarm probability of 0.2 per cent. 20 s cadences being collected during Year 3 should confirm or reject our detection. From eclipse timing measurements we were able to confirm that the orbital period is stable, with an upper limit to any period change of 5.75 × 10−13 s s−1. The apparent offset of the secondary eclipse is consistent with the predicted Rømer delay when the primary mass is that of a canonical extended horizontal branch star. Using parallax and a spectral energy distribution corroborates that the mass of the primary in AA Dor is canonical, and its radius and luminosity are consistent with an evolutionary state beyond core helium burning. The mass of the secondary is found to be at the limit of hydrogen burning.
Characterization of Total and Unprotonated (Free) Nicotine Content of Nicotine Pouch Products
Authors: Stanfill Stephen , Tran Hang , Tyx Robert , Fernandez Carolina , Zhu Wanzhe , Marynak Kristy , King Brian , Valentín-Blasini Liza , Blount Benjamin C , Watson Clifford 
Published: March 2021

Abstract

Introduction
Nicotine pouch products, oral smokeless products that contain nicotine but no tobacco leaf material, have recently entered the US marketplace. Available data indicate sales of these products in the United States have increased since 2018; however, the extent of use among US youth and adults is uncertain.

Methods
To assay the chemistry of these emerging tobacco products, we analyzed 37 nicotine pouch brands from six total manufacturers. Almost all of the products had flavor descriptors (36 of 37), such as mint, licorice, coffee, cinnamon, and fruit. The amount of free nicotine, the form most easily absorbed, was calculated for each product using total nicotine, product pH, the appropriate pKa, and the Henderson–Hasselbalch equation.

Results
Nicotine pouch products varied in pouch content mass, moisture content (1.12%‒47.2%), alkalinity (pH 6.86‒10.1), and % free nicotine (7.7%‒99.2%). Total nicotine content ranged from 1.29 to 6.11 mg/pouch, whereas free nicotine ranged from 0.166 to 6.07 mg/pouch. These findings indicate that nicotine and pH levels found in some of these nicotine pouches are similar to conventional tobacco products, such as moist snuff and snus, and that most of these pouch products are flavored.

Conclusions
Although these products likely lack many tobacco-related chemicals, each product analyzed contained nicotine, which is both addictive and can harm human health. Given that nicotine pouches may appeal to a spectrum of users, from novice to experienced users, it is important to include these emerging tobacco products in tobacco control research, policy, and practice.

Implications
These “tobacco-free” nicotine pouches have similar pH and nicotine content to conventional tobacco products, such as moist snuff and snus. Although they lack many tobacco-related chemicals, most are highly flavored which could increase experimentation from new users. Given that nicotine pouches may appeal to a spectrum of users, from novice to experienced users, in terms of their flavors and nicotine content, it is important to examine and include these emerging tobacco products as they relate to tobacco control research, policy, and practice.
Voting Age Reform, Political Partisanship and Multi-Level Governance in the UK: The Party Politics of ‘Votes-at-16’
Authors: Tonge Jonathan , Loughran Thomas , Mycock Andrew 
Published: March 2021

Abstract
The UK is now a multi-level polity with asymmetrical minimum ages of enfranchisement. The franchise was first extended to 16- and 17-year-olds in the 2014 Scottish independence referendum. The Scottish and Welsh governments now permit 16- and 17-year-olds to vote in elections to their devolved parliaments and local councils. The Northern Ireland Executive and the devolved authorities in England do not, however, have the power to change the voting age, and across all four nations of the UK, the age of franchise remains 18 for elections to the Westminster Parliament. The previous extension of the age of franchise, from 21 to 18 in 1969, attracted little controversy or political partisanship. But while there has been considerable political consensus regarding voting age reform in Scotland and Wales, debate over ‘Votes-at-16’ for Westminster elections has witnessed growing party-based partisanship. This article draws upon elite interviews with politicians across the political spectrum elected to Westminster and the devolved institutions on their attitudes to voting age reform, conducted as part of a 2-year Leverhulme Trust ‘Lowering the Voting Age in the UK’ project. The article argues that the multi-level party politics of the ‘Votes-at-16’ debate has consolidated rival party opinions on voting age reform at Westminster but not beyond.
Relationship Between Post-Traumatic Stress Disorder Symptoms and Chronic Pain-Related Symptom Domains Among Military Active Duty Service Members
Authors: Li Hongjin , Flynn Diane M , Highland Krista B , Barr Patricia K , Langford Dale J , Doorenbos Ardith Z 
Published: March 2021

Abstract

Objective
This study examined the relationships between symptom domains relevant to post-traumatic stress disorder (PTSD) diagnosis, PTSD screening, and chronic pain-related symptoms (pain intensity, pain interference, physical function, fatigue, depression, anxiety, anger, satisfaction with social roles) experienced by active duty military service members with chronic pain.

Design
ross-sectional study.

Setting
This study was conducted at the Interdisciplinary Pain Management Center (IPMC) at Madigan Army Medical Center between 2014 and 2018.

Subjects
Active duty service members receiving care at IPMC (n = 2745) were included in this study.

Methods
Independent sample t test was conducted to compare pain intensity and pain-related measures of physical, emotional, and social functioning among patients with and without a PTSD diagnosis or PTSD positive screen (≥3 symptoms). Relative weight analysis was used to identify the relative importance of each PTSD symptom cluster (e.g., intrusion, avoidance, hyperarousal, emotional numbness) to pain and related domains.

Results
Approximately 27.9% of the patients had a positive screen for PTSD, and 30.5% of the patients had a PTSD diagnosis. Patients with PTSD diagnosis and positive screening had higher pain interference and lower physical function and social satisfaction scores (P &lt; 0.001) and had increased anger, anxiety, fatigue, and depression scores (P &lt; 0.001). Emotional numbness accounted for the largest proportion of variance in average pain intensity, pain interference, and psychological functioning, and avoidance accounted for the largest proportion of variance in physical function.

Conclusion
To improve treatment effectiveness and overall functioning for active duty military patients, integrated treatment and therapies targeted to reducing chronic pain and PTSD symptoms (focus on emotional numbness and avoidance) are recommended.
Utilization Patterns of Skeletal Muscle Relaxants Among Commercially Insured Adults in the United States from 2006 to 2018
Authors: Li Yan , Delcher Chris , Reisfield Gary M , Wei Yu-Jung , Brown Joshua D , Winterstein Almut G 
Published: March 2021

AbstractObjectiveTo examine the prevalence and duration of skeletal muscle relaxant (SMR) treatment among commercially insured adults in the United States.MethodsWe used the MarketScan Research Database to identify a cohort of adults 18 to 64 years who had ≥2-year continuous enrollment between 2005 and 2018. We estimated the prevalence of SMR treatment using a repeated cross-sectional design and derived treatment duration using the Kaplan-Meier method. Analyses were stratified by age group, sex, geographic region, individual SMR agent, and musculoskeletal disorder.Results48.7 million individuals were included. Treatment prevalence ranged from 61.5 to 68.3 per 1,000. About one-third of users did not have a preceding musculoskeletal disorder diagnosis. Cyclobenzaprine was the dominant agent accounting for &gt;50% of prescriptions. The considerable growth in the use of baclofen, tizanidine, and methocarbamol paralleled with a decline in carisoprodol and metaxalone use. The prevalence was highest in the South while lowest in the Northeast. The median treatment duration was 14 days with 4.0%, 1.9%, and 1.0% of individuals using SMRs for more than 90, 180, and 365 days, respectively. Compared with cyclobenzaprine, patients initiating baclofen, tizanidine, and carisoprodol had longer treatment duration.ConclusionsSMRs are widely used in the United States. Their use slightly increased in recent years, but trends varied among individual agents, patient groups, and geographic regions. Despite limited evidence to support efficacy, a sizable number of U.S. adults used SMRs for long-term and off-label conditions. Further study is needed to understand determinants of treatment as well as outcomes associated with such use.
The Role of Intrathecal Morphine for Postoperative Analgesia in Primary Total Joint Arthroplasty under Spinal Anesthesia: A Systematic Review and Meta-Analysis
Authors: Wang Li-Min , Zhang Zhen , Yao Ru-Zhan , Wang Guang-Lin 
Published: March 2021

Abstract

Objective
To assess the efficacy and safety of intrathecal morphine (ITM) for postoperative analgesia in primary total joint arthroplasty (TJA) under spinal anesthesia and to explore the dose-response relationship for analgesic efficacy or risk of side effects.

Methods
We searched MEDLINE, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for any studies meeting the inclusion criteria. All the data were summarized using the random effects model. Subgroup analyses were performed based on the surgical procedure and dose of ITM. Meta-regression was used to explore the dose-response relationship.

Results
Eighteen randomized controlled trials were included. Compared with the placebo or blank control, ITM reduced the postoperative 24-h morphine consumption by 10.07 mg and prolonged the duration of analgesia. However, ITM significantly increased the risk of pruritus by 2.79 fold, with a tendency to increase the risk of postoperative nausea and/or vomiting (P = 0.08). No difference was observed regarding the length of stay (LOS) and incidence of respiratory depression or urinary retention. Furthermore, meta-regression showed a linear dose-response relationship for the postoperative 24-h morphine consumption but no linear dose-response relationship for the risk of side effects.

Conclusions
Adding morphine to intrathecal anesthetics provides a prolonged and robust analgesic effect without significantly increasing the risk of side effects other than pruritus. Although we found a linear dose-response relationship for the postoperative 24-h morphine consumption, the optimal dose of ITM remains to be further explored in high-quality RCTs with a large sample size.
Assessing sexual function in middle-aged sexually active Spanish women: a community-based study focusing on the intimate partner
Authors: Martínez-Madrid Maria M. , Arnau-Sánchez José , González-Cuello Ana M. 
Published: March 2021

Abstract

Objective:
This study evaluated sexual function, the influence of the relationship with the intimate partner, and the factors related to sexual function in middle-aged Spanish women.

Methods:
The methodology entailed a cross-sectional study of 187 sexually active women aged 40-59 years. The participants were randomly recruited from primary public health care. They completed the 6-item Female Sexual Function Index (FSFI-6), the short-form Woman Abuse Screening Tool (WAST), and a sociodemographic questionnaire. Descriptive and inferential analysis was performed.

Results:
The participants’ median age was 49 years, 90.4% had a steady intimate partner, 54.5% were postmenopausal, 43.3% had chronic diseases, 12.3% reported alcohol abuse, and 35.8% smoked. The prevalence of low sexual function was 33.16% in all the women, and 44.12% in the postmenopausal women (an FSFI-6 total score ≤ 19 reflects low sexual function). WAST screening detected 17.65% cases of intimate partner violence (WAST total score ≤ 1), with low sexual function in 87.9%. Multiple linear regression analysis models revealed that the lowest total FSFI-6 scores (worst sexual function) were negatively associated with intimate partner violence (IPV), depression, hysterectomy, and associated female issues. The scores in the FSFI-6 domains (desire, arousal, lubrication, orgasm, satisfaction, and pain) were linked to IPV (P < 0.001), except for lubrication (P < 0.001 postmenopausal).

Conclusion:
Low sexual function was more common in women who were positively screened for IPV. It was identified as a key factor, which contributes to deteriorating middle-aged women's sexual health.