bluuebunny/crossref_metadata_2025_split huggingface dataset:
When Should You Adjust Standard Errors for Clustering?
Authors: Abadie Alberto , Athey Susan , Imbens Guido W , Wooldridge Jeffrey M 
Published: October 2022

AbstractClustered standard errors, with clusters defined by factors such as geography, are widespread in empirical research in economics and many other disciplines. Formally, clustered standard errors adjust for the correlations induced by sampling the outcome variable from a data-generating process with unobserved cluster-level components. However, the standard econometric framework for clustering leaves important questions unanswered: (i) Why do we adjust standard errors for clustering in some ways but not others, for example, by state but not by gender, and in observational studies but not in completely randomized experiments? (ii) Is the clustered variance estimator valid if we observe a large fraction of the clusters in the population? (iii) In what settings does the choice of whether and how to cluster make a difference? We address these and other questions using a novel framework for clustered inference on average treatment effects. In addition to the common sampling component, the new framework incorporates a design component that accounts for the variability induced on the estimator by the treatment assignment mechanism. We show that, when the number of clusters in the sample is a nonnegligible fraction of the number of clusters in the population, conventional clustered standard errors can be severely inflated, and propose new variance estimators that correct for this bias.
Why do Borrowers Default on Mortgages?
Authors: Ganong Peter , Noel Pascal 
Published: October 2022

AbstractThere are three prevailing theories of mortgage default: strategic default (driven by negative equity), cash flow default (driven by negative life events), and double-trigger default (where both negative triggers are necessary). It has been difficult to compare these theories in part because negative life events are measured with error. We address this measurement error using a comparison group of borrowers with no strategic-default motive. Our central finding is that only 6% of underwater defaults are caused exclusively by negative equity, an order of magnitude lower than previously thought. We then analyze the remaining defaults. We find that 70% are driven solely by negative life events (i.e., cash flow defaults), while 24% are driven by the interaction between negative life events and negative equity (i.e., double-trigger defaults). Together, the results provide a full decomposition of the theories underlying borrower default and suggest that negative life events play a central role.
Economic assessment of foot-and-mouth disease outbreaks in Brazil
Authors: de Menezes Taís Cristina , Countryman Amanda M , Ferreira Filho Joaquim Bento de Souza , Ferreira Fernando 
Published: October 2022

AbstractFoot-and-mouth disease (FMD) outbreaks in cloven-hoofed animals cause substantial economic impacts because of animal depopulation, increased government spending on control, eradication and surveillance measures, and bans on international trade. This study employs a computable general equilibrium (CGE) modeling framework in tandem with results from an epidemiological model to evaluate the economic consequences of a hypothetical FMD outbreak in Brazil. FMD-induced productivity losses and restrictions on international trade of livestock and meat products are applied as exogenous shocks in the economic model. Results show increased bilateral trade of beef and pork, mainly in South America, North Africa, and Russia. Simulated welfare losses in Brazil range from $132 million to $271 million depending on the severity of trade restrictions imposed. This study expands the rich literature on animal health economics. Results highlight the importance of maintaining the health of Brazilian herds, especially when considering Brazil's position as one of the main meat suppliers in the international market.
Brain responses to the vicarious facilitation of pain by facial expressions of pain and fear
Authors: Khatibi Ali , Roy Mathieu , Chen Jen-I , Gill Louis-Nascan , Piche Mathieu , Rainville Pierre 
Published: October 2022

AbstractObserving pain in others facilitates self-pain in the observer. Vicarious pain facilitation mechanisms are poorly understood. We scanned 21 subjects while they observed pain, fear and neutral dynamic facial expressions. In 33% of the trials, a noxious electrical stimulus was delivered. The nociceptive flexion reflex (NFR) and pain ratings were recorded. Both pain and fear expressions increased self-pain ratings (fear &gt; pain) and the NFR amplitude. Enhanced response to self-pain following pain and fear observation involves brain regions including the insula (INS) (pain &gt; fear in anterior part), amygdala, mid-cingulate cortex (MCC), paracentral lobule, precuneus, supplementary motor area and pre-central gyrus. These results are consistent with the motivational priming account where vicarious pain facilitation involves a global enhancement of pain-related responses by negatively valenced stimuli. However, a psychophysiological interaction analysis centered on the left INS revealed increased functional connectivity with the aMCC in response to the painful stimulus following pain observation compared to fear. The opposite connectivity pattern (fear &gt; pain) was observed in the fusiform gyrus, cerebellum (I–IV), lingual gyrus and thalamus, suggesting that pain and fear expressions influence pain-evoked brain responses differentially. Distinctive connectivity patterns demonstrate a stronger effect of pain observation in the cingulo-insular network, which may reflect partly overlapping networks underlying the representation of pain in self and others.
A survey of Mathematics Learning Support in the United States
Authors: Mac an Bhaird Ciarán , Thomas David A 
Published: October 2022

Abstract
Mathematics Learning Support (MLS) has been widely available in Higher Education Institutions in the United States (US) for decades. However, until recently, there has been little research that considered the extent of provision. In this paper, we present the results of a survey of MLS with responses from 268 institutions across the US, which indicate that such support is well established across responding institutions. To place these results in context, we compare them to other recent international surveys of provision. We discuss what these findings mean and the collaborative opportunities that are available for US and international practitioners and researchers in this area.
Racial and Ethnic Disparities in Primary Cesarean Birth and Adverse Outcomes Among Low-Risk Nulliparous People
Authors: Fishel Bartal Michal , Chen Han-Yang , Mendez-Figueroa Hector , Wagner Stephen M. , Chauhan Suneet S.P. 
Published: October 2022

OBJECTIVE:
To compare trend of primary cesarean delivery rate and composite neonatal and maternal adverse outcomes in low-risk pregnancies among racial and ethnic groups: non-Hispanic White, non-Hispanic Black, and Hispanic.

METHODS:
This population-based cohort study used U.S. vital statistics data (2015–2019) to evaluate low-risk, nulliparous patients with nonanomalous singletons who labored and delivered at 37–41 weeks of gestation. The primary outcome was the primary cesarean delivery rate. Secondary outcomes included composite neonatal adverse outcome (Apgar score less than 5 at 5 minutes, assisted ventilation for more than 6 hours, seizure, or death), and composite maternal adverse outcome (intensive care unit admission, blood transfusion, uterine rupture, or unplanned hysterectomy), as well as infant death. Multivariable Poisson regression models were used to estimate adjusted relative risks (aRR) and 95% CIs.

RESULTS:
Among 4.3 million births, 60.6% identified as non-Hispanic White, 14.6% identified as non-Hispanic Black, and 24.8% identified as Hispanic. The rate of primary cesarean delivery was 18.5% (n=804,155). An increased risk for cesarean delivery was found in non-Hispanic Black (21.7%, aRR 1.24, 95% CI 1.23–1.25) and Hispanic (17.3%, aRR 1.09, 95% CI 1.09–1.10) individuals, compared with non-Hispanic White individuals (18.1%) after multivariable adjustment. There was an upward trend in the rate of primary cesarean delivery in all racial and ethnic groups (P for linear trend<0.001 for all groups). However, the racial and ethnic disparity in the rate of primary cesarean delivery remained stable during the study period. The composite neonatal adverse outcome was lower in Hispanic individuals in all newborns (10.7 vs 8.3 per 1,000 live births, aRR 0.74, 95% CI 0.72–0.75), and in newborns delivered by primary cesarean delivery (18.5 vs 15.0 per 1,000 live births, aRR 0.73, 95% CI 0.70–0.76), compared with non-Hispanic White individuals.

CONCLUSION:
Using a nationally representative sample in the United States, we found racial and ethnic disparities in the primary cesarean delivery rate in low-risk nulliparous patients, which persisted throughout the study period.
Periurethral and Anterior Vaginal Wall Masses
Authors: Jacox Natalie , Yao Henry Han-I , Baverstock Richard , Trpkov Kiril , Carlson Kevin 
Published: October 2022

OBJECTIVE:
To describe the etiology and presenting symptoms of periurethral and anterior vaginal wall masses in a large series of patients in an academic institution.

METHODS:
A retrospective chart review of 126 patients presenting and undergoing treatment for periurethral and anterior vaginal wall masses between November 2001 and July 2021 was completed. Clinicopathologic data were extracted. Ethics approval was obtained. The primary objective of this study was to determine the etiology of these masses; secondary objectives included determining the rates of presenting symptoms, complications, resolution of stress urinary incontinence (SUI), and de novo SUI.

RESULTS:
The median age of patients was 42 years. The most common etiology was urethral diverticula (39.7%), followed by Skene gland cysts or abscesses (30.2%). The rate of malignancy was 1.6%, and the rate of infection was 21.4%. The most common presenting symptoms were sensation of mass (78.6%), dyspareunia (52.4%), and discharge (46.0%). The rate of surgical complications was 9.5%. Three patients had recurrence on follow-up, but there were no recurrent urethral diverticula after excision. The rate of de novo SUI was 5.6%. The rate of resolution of SUI was 67.6%, and all patients who had slings reported resolution of SUI.

CONCLUSION:
Urethral diverticula and Skene gland cysts or abscesses accounted for 70% of periurethral and anterior vaginal wall masses in this series. Treatment by complete excision is usually successful.
Temporal Patterns and Adoption of Germline and Somatic BRCA Testing in Ovarian Cancer
Authors: Huepenbecker Sarah P. , Wright Jason D. , Downer Mary K. , Incerti Devin , Luhn Patricia , Dolado Ignacio , Bastiere-Truchot Lydie , Lin Yvonne G. , Chan John K. , Meyer Larissa A. 
Published: October 2022

OBJECTIVE:
To describe the testing rate, patient characteristics, temporal trends, timing, and results of germline and somatic BRCA testing in patients with ovarian cancer using real-world data.

METHODS:
We included a cross-sectional subset of adult patients diagnosed with ovarian cancer between January 1, 2011, and November 30, 2018, who received frontline treatment and were followed for at least 1 year in a real-world database. The primary outcome was receipt of BRCA testing, classified by biosample source as germline (blood or saliva) or somatic (tissue). Lines of therapy (frontline, second line, third line) were derived based on dates of surgery and chemotherapy. Descriptive statistics were analyzed.

RESULTS:
Among 2,557 patients, 72.2% (n=1,846) had at least one documented BRCA test. Among tested patients, 62.5% (n=1,154) had only germline testing, 10.6% (n=197) had only somatic testing, and 19.9% (n=368) had both. Most patients had testing before (9.7%, n=276) or during (48.6%, n=1,521) frontline therapy, with 17.6% (n=273) tested during second-line and 12.7% (n=129) tested during third-line therapy. Patients who received BRCA testing, compared with patients without testing, were younger (mean age 63 years vs 66 years, P<.001) and were more likely to be treated at an academic practice (10.4% vs 7.0%, P=.01), with differences by Eastern Cooperative Oncology Group performance score (P<.001), stage of disease (P<.001), histology (P<.001), geography (P<.001), and type of frontline therapy (P<.001), but no differences based on race or ethnicity. The proportion of patients who received BRCA testing within 1 year of diagnosis increased from 24.6% of patients in 2011 to 75.6% of patients in 2018.

CONCLUSION:
In a large cohort of patients with ovarian cancer, significant practice disparities existed in testing for actionable BRCA mutations. Despite increased testing over time, many patients did not receive testing, suggesting missed opportunities to identify patients appropriate for targeted therapy and genetic counseling.
Association of Driving Distance to Maternity Hospitals and Maternal and Perinatal Outcomes
Authors: Minion Sarah C. , Krans Elizabeth E. , Brooks Maria M. , Mendez Dara D. , Haggerty Catherine L. 
Published: October 2022

OBJECTIVE:
To assess whether there are associations between driving distance from the patient residence to the delivery hospital and adverse maternal and perinatal health outcomes.

METHODS:
We performed a retrospective cohort study using 2011–2015 Pennsylvania birth records of live births at 20 weeks of gestation or more, excluding inpatient hospital transfers or implausible distances. The shortest driving distance from patient residence to the delivery hospital was calculated in ArcGIS and was evaluated in association with a composite of adverse maternal outcomes (blood transfusion, unplanned operation, ruptured uterus, unplanned hysterectomy, or intensive care unit admission) and neonatal intensive care unit (NICU) admission. Multivariable-adjusted Poisson models were used to estimate relative risks with 95% CIs with a referent difference of 1 km distance to the delivery hospital.

RESULTS:
A total 662,245 birth records were included, and the median driving distance to the hospital was 11.3 km (interquartile range 5.4–21.6 km). The overall rate of the composite maternal outcome was 0.6% and of NICU admission was 8.4%. Compared with the referent distance, increasing driving distance was significantly associated with increased adjusted risks of the maternal composite outcome (adjusted relative risk [aRR] 1.22, 95% CI 1.07–1.36 for 60 km; aRR 1.36, 95% CI 1.19–1.53 for 70 km; and 1.53, 95% CI 1.31–1.75 for 80 km) and NICU admission (aRR 1.70, 95% CI 1.65–1.76 for 60 km; aRR 1.96, 95% CI 1.90–2.02 for 70 km; and aRR 2.25, 95% CI 2.18–2.33 for 80 km).

CONCLUSION:
Longer distances to the delivery hospital were associated with greater risk of adverse maternal outcomes and NICU admission. Whether these finding reflect health care delivery deficits or simply serve as a marker of social deprivation requires further study.
Peptide Mimotope-Enabled Quantification of Natalizumab Arm Exchange During Multiple Sclerosis Treatment
Authors: Page Lesley J. , Lagunas-Acosta Jacqueline , Heussen Raphaela , Castellana Edward T. , Messmer Bradley T. 
Published: October 2022

Background:
Natalizumab, a therapeutic antibody used to treat multiple sclerosis, undergoes in vivo Fab arm exchange to form a monovalent bispecific antibody. Although highly efficacious, the immunosuppressive activity of natalizumab has been associated with JC polyomavirus-driven progressive multifocal leukoencephalopathy (PML). Development of assays that can distinguish between and quantify bivalent (unexchanged) and monovalent (exchanged) forms of natalizumab in clinical samples may be useful for optimizing extended interval dosing and reducing the risk of PML.

Methods:
In vitro natalizumab arm exchange was conducted, along with peptide mimotope and anti-idiotype surface capture chemistry, to enable the development of enzyme-linked immunosorbent assays.

Results:
An assay using a unique peptide VeritopeTM was developed, which can exclusively bind to bivalent natalizumab. In combination with enzyme-linked immunosorbent assays that quantifies total natalizumab, the assay system allows quantification of both natalizumab forms.

Conclusions:
In this article, a novel assay for the quantification of unexchanged and exchanged natalizumab variants in clinical samples was developed. This assay will enable investigations into the clinical significance of the relationship of PK/PD with the monovalent-to-bivalent ratio, as it relates to the efficacy of the drug and risk of PML.
The Influence of HEV-Filtering Contact Lenses on Behavioral Indices of Glare
Authors: Renzi-Hammond Lisa M. , Buch John , Xu Jie , Hammond Billy R. 
Published: October 2022

Objectives:
We assessed the effects of a HEV-filtering contact lens on positive dysphotopsia (halos and starbursts) and a behavioral index of scatter measured using two-point light thresholds. These effects were assessed by direct comparison to a clear (i.e., non-HEV filtering) contact lens tested in the fellow eye.

Methods:
Sixty-one subjects were randomized and fit with study lenses and 58 subjects completed the study. A double-masked contralateral design was used. Subjects were randomized to test lens-OD, control lens-OS, or vice versa. Participants were exposed to a point source of broadband simulated sunlight (a 403-nm condition was also tested) that created the appearance of halos/starbursts. The degree of dysphotopsia was measured as the diameter of broadband and violet-induced halos, and broadband light-induced starbursts. Two-point thresholds were assessed as the minimum resolvable distance between two pinpoints of light.

Results:
The HEV-filtering lens was statistically superior (P<0.0001) to the clear lens in all the conditions tested. The HEV-filtering lens significantly reduced halo diameter by 30%, starburst diameter by 23%, and resolvable distance in the two-point condition by 18% (white) and 30% (violet).

Conclusions:
HEV-filtering contact lenses can reduce some deleterious effects of bright broadband light by decreasing light scatter, halos, and starbursts.
Recurrent ESBL Escherichia coli Urosepsis in a Pediatric Renal Transplant Patient Treated With Antibiotics and Bacteriophage Therapy
Authors: Gainey Andrew B. , Daniels Robert , Burch Anna-Kathryn , Hawn Jason , Fackler Joseph , Biswas Biswajit , Brownstein Michael J. 
Published: October 2022

Introduction:
Treating recurrent multidrug resistant (MDR) urosepsis in pediatric transplant recipients can be challenging. Particularly when antibiotics fail to prevent future occurrence and the nidus is seemingly undiscoverable. While there is an increasing amount of data on phage therapy, to our knowledge, there are no published cases involving pediatric renal transplant recipients. Therefore, we present a challenging clinical case in which phage therapy was used in a pediatric renal transplant recipient who developed recurrent MDR urosepsis with an unclear source.

Case Presentation:
Our patient was a 17-year-old female who initially developed urosepsis caused by extended-spectrum β-lactamase (ESBL) Escherichia coli, while being treated with an immunosuppressant regimen because of kidney rejection secondary to poor immunosuppression therapy compliance. She was admitted to our hospital intermittently for 4 months with 4 episodes of urosepsis caused by ESBL E. coli. She received multiple courses of antibiotics (mainly ertapenem) and underwent a fecal material transplant to eradicate her ESBL E. coli colonized gastrointestinal tract. Because of recurrent development of urosepsis after antibiotic treatment, she later underwent treatment with a phage cocktail consisting of 2 isolate-specific phages. After a prolonged antibiotic course and subsequent 3-week intravenous phage treatment, she had no ESBL E. coli in her urinary cultures for 4 years post-treatment.

Discussion:
This case highlights the challenges of treating recurrent ESBL E. coli infections in a pediatric renal transplant patient and provides evidence that phage therapy may prove useful in such cases.
Effect of a new phacoemulsification and aspiration handpiece on anterior chamber stability
Authors: Suzuki Hisaharu , Igarashi Tsutomu , Takahashi Hiroshi 
Published: October 2022

Purpose:
To evaluate the responsiveness of 3 phacoemulsification and aspiration (PEA) systems and a new handpiece to occlusion break by measuring anterior chamber depth (ACD) and intraocular pressure (IOP).

Setting:
Zengyo Suzuki Eye Clinic, Kanagawa, Japan.

Design:
Experimental study.

Methods:
ACD change during intentional occlusion breaks was observed and evaluated using the slit side view (SSV) method and IOP measurement with the Centurion Vision System (Group 1), Centurion Vision System with Active Sentry (Group 2), Infiniti Vision System (Group 3), and Constellation Vision System (Group 4). 5 eyes were included per group. Occlusion breaks were triggered at IOP of 30 mm Hg, vacuum limits of 550 mm Hg, and aspiration rate of 40 mL/min. ACD change ratio, surge duration, and surge volume were analyzed from videos of SSV and IOP measurement.

Results:
The smallest ACD change was observed in Group 2 with SSV. ACD change ratios in Groups 1 to 4 were 17.5% ± 3.9%, 7.3% ± 1.2%, 35.7% ± 9.5%, and 74.1 ± 7.7%, respectively. Surge duration and surge volume were calculated only for Groups 1 and 2 and were significantly lower in Group 2 than in Group 1 (0.32 ± 0.03 vs 1.17 ± 0.07 seconds; 18.91 ± 4.70 vs 45.70 ± 0.83 μL). In these 2 groups, ACD change ratio correlated with surge volume.

Conclusions:
This study evaluated the responsiveness of 3 PEA systems and a new handpiece to occlusion breaks by measuring IOP and ACD. The Active Sentry system was useful for maintaining the ACD even during occlusion breaks.
Comparative Analysis of Robotics-Assisted and Manual Insertions of Cochlear Implant Electrode Arrays
Authors: Claussen Alexander D. , Shibata Seiji B. , Kaufmann Christopher R. , Henslee Allan , Hansen Marlan R. 
Published: October 2022

Hypothesis
Robotics-assisted cochlear implant (CI) insertions will result in reduced intracochlear trauma when compared with manual, across multiple users.

Background
Whether intracochlear trauma and translocations are two factors that may contribute to significant variability in CI outcomes remains to be seen. To address this issue, we have developed a robotics-assisted insertion system designed to aid the surgeon in inserting electrode arrays with consistent speeds and reduced variability. This study evaluated the effect of robotics-assisted insertions on the intracochlear trauma as compared with manual insertions in cadaveric cochleae in a simulated operative environment.

Methods
Twelve neurotologists performed bilateral electrode insertions into cochleae of full cadaveric heads using both the robotics-assisted system and manual hand insertion. Lateral wall electrodes from three different manufacturers (n = 24) were used and randomized between surgeons. Insertion angle of the electrode and trauma scoring were evaluated using high-resolution three-dimensional x-ray microscopy and compared between robotics-assisted and manual insertions.

Results
Three-dimensional x-ray microscopy provided excellent resolution to characterize the in situ trauma and insertion angle. Robotics-assisted insertions significantly decreased insertional intracochlear trauma as measured by reduced trauma scores compared with manual insertions (average: 1.3 versus 2.2, device versus manual, respectively; p < 0.05). There was no significant difference between insertion angles observed for manual and robotics-assisted techniques (311 ± 131° versus 307 ± 96°, device versus manual, respectively).

Conclusions
Robotics-assisted insertion systems enable standardized electrode insertions across individual surgeons and experience levels. Clinical trials are necessary to investigate whether insertion techniques that reduce insertional variability and the likelihood of intracochlear trauma also improve CI auditory outcomes.