bluuebunny/crossref_metadata_2025 huggingface dataset:
Using web-sourced photography to explore the diet of a declining African raptor, the Martial Eagle (Polemaetus bellicosus)
Authors: Naude Vincent N , Smyth Lucy K , Weideman Eleanor A , Krochuk Billi A , Amar Arjun
Published: July 2019

Understanding a species’ diet can be critical for effective conservation. While several traditional methods for assessing raptor diet exist, many pose inherit biases and often require extensive fieldwork that can limit sample sizes and the geographic scope of studies. This is especially true for species that nest at low densities (e.g., large eagles). Recently, several studies have demonstrated the value of web-sourced photographs in tackling ecological and evolutionary questions. Specialized software (e.g., MORPHIC) has been developed to systematically extract Google Images for this purpose. We used this approach to explore the diet of Martial Eagles (Polemaetus bellicosus). A shortage of prey is one of the proposed hypotheses for recent population declines across their range. Of the 4,872 photographs selected by MORPHIC, 254 were usable (5%). Birds, mammals, and reptiles each contributed similarly to overall identified prey. Helmeted Guineafowl (Numida meleagris) were the most important bird prey identified (12% of overall prey). The 4 most important mammalian prey species were Thompson’s gazelle (Eudorcas thomsonii; 5%), impala (Aepyceros melampus; 4%), common duiker (Sylvicapra grimmia; 4%), and banded mongoose (Mungos mungo; 4%). Reptile prey was dominated by monitor lizards (Varanus spp.; 21%). Prey class proportions differed significantly by regions with mammalian prey being more common in eastern Africa and reptile prey being more common in southern Africa. Within South Africa, reptile prey proportion was greater in the east than in the west. These corroborate existing prey composition studies. Prey composition differed between age classes, with adult eagles preying on more birds than non-adults. There was no significant difference in the average estimated prey weight by eagle age or feeding position (ground, perched, or flying). Our results suggest that this approach may offer a useful method to explore the diet for raptor species that are well photographed across their range, at minimal cost and research effort.
Effects of individual misidentification on estimates of survival in long-term mark–resight studies
Authors: Tucker Anna M , McGowan Conor P , Robinson Robert A , Clark Jacquie A , Lyons James E , DeRose-Wilson Audrey , Du Feu Richard , Austin Graham E , Atkinson Philip W , Clark Nigel A
Published: July 2019

All ecological measurements are subject to error; the effects of missed detection (false negatives) are well known, but the effects of mistaken detection (false positives) are less understood. Long-term capture–recapture datasets provide valuable ecological insights and baselines for conservation and management, but where such studies rely on noninvasive re-encounters, such as field-readable color bands, there is the potential to accumulate detection errors as the length of the study and number of tags deployed increases. We investigated the prevalence and effects of misreads in a 10-yr dataset of Red Knots (Calidris canutus rufa) marked with field-readable leg flags in Delaware, USA. We quantified the effects of misreads on survival estimation via a simulation study and evaluated whether removal of individuals only reported once in a year (potential misreads) influenced survival estimation from both simulated datasets and our case study data. We found overall apparent error rates of 0.31% (minimum) to 6.6% (maximum). Observer-specific error rates and the variation among observers both decreased with the number of flags an observer recorded. Our simulation study showed that misreads lead to spurious negative trends in survival over time, particularly for long-term studies. Removing all records in which a flag was only recorded once in a sampling occasion reduced bias and eliminated spurious negative trends in survival but also reduced precision in survival estimates. Without data filtering, we found a slight decrease in Red Knot annual survival probability from 2008 to 2018 (β = −0.043 ± 0.03), but removing all single-observation records resulted in no apparent trend (β = −0.0074 ± 0.02). Spurious trends in demographic rates could influence inference about population trajectories and resultant conservation decision-making. Data filtering could eliminate errors, but researchers should carefully consider the tradeoff between precision obtained by larger sample sizes and potential bias due to misreads in their data.
The importance of disturbance and forest structure to bird abundance in the Black Hills
Authors: Matseur Elizabeth A , Millspaugh Joshua J , Thompson Frank R , Dickerson Brian E , Rumble Mark A
Published: July 2019

Many North American birds associated with forest disturbances such as wildfire and mountain pine beetle (Dendroctonus ponderosae) outbreaks are declining in abundance. More information on relationships between avian abundance and forest structure and disturbance is needed to guide conservation and management. Our objective was to determine densities of American Three-toed Woodpecker (Picoides dorsalis), Black-backed Woodpecker (Picoides arcticus), Red-breasted Nuthatch (Sitta canadensis), Brown Creeper (Certhia americana), and White-winged Junco (Junco hyemalis aikeni) in relation to vegetation characteristics and disturbance at the point and landscape level in the Black Hills and Bear Lodge Mountains of South Dakota and Wyoming. We conducted 3 point counts from late March to late June 2015 and 2016 at more than 2,300 locations distributed across a gradient of forest structure and disturbance types. We estimated densities using 3-level hierarchical time-removal models that simultaneously estimated abundance, availability, and detection probability. Black-backed Woodpeckers were positively related to percent area in 1- to 3-year-old wildfires and Brown Creepers were positively associated with percent area in 4- to 5-year-old wildfires; however, Red-breasted Nuthatches were negatively related to percent area in 3- to 5-year-old wildfires. With the exception of American Three-toed Woodpeckers, species were positively related to percent cover of beetle-killed trees. Brown Creepers, White-winged Juncos, and Red-breasted Nuthatches had mixed responses to percent overstory canopy cover. White-winged Juncos also had a positive association with percent ground vegetation at the point and landscape level. Brown Creepers were strongly linked with spruce vegetation type. American Three-toed Woodpeckers, which are thought to occupy spruce forest in the Black Hills, did not show a strong relationship with any covariates. Maintaining some areas of natural disturbances along with heterogeneity of vegetation characteristics within stands and at the landscape scale will benefit the needs of a diverse bird community in the Black Hills.
No evidence of a demographic response to experimental herbicide treatments by the White-crowned Sparrow, an early successional forest songbird
Authors: Rivers James W , Verschuyl Jake , Schwarz Carl J , Kroll Andrew J , Betts Matthew G
Published: July 2019

Early-successional forest birds, which depend on disturbance events within forested landscapes, have received increased conservation concern because of long-term population declines. Herbicides are often used to control vegetation within early-successional forests, with unknown effects on avian vital rates. We used a large-scale experiment to test how nest and post-fledging survival were influenced by herbicide intensity within managed conifer plantations across 2 breeding seasons. We created a gradient of 4 stand-scale herbicide treatments (light, moderate, and intensive, and no-spray control) and evaluated the reproductive response of the White-crowned Sparrow (Zonotrichia leucophrys), a declining songbird in managed forest landscapes of the Pacific Northwest. Against initial predictions, we found no evidence that either daily nest survival (n > 760 nests across all treatments) or post-fledging survival (n = 70 individuals reared in control and moderate treatments) were influenced by herbicide application intensity. Increased herbicide intensity resulted in an extensive reduction in vegetation cover at both stand and nest-patch scales; in contrast, vegetative cover at nest sites did not differ across herbicide treatments, nor was nest survival related to vegetation concealment measures. As the largest experimental investigation to assess forest herbicide effects on songbird demography, our study indicates that components of sparrow reproductive success were not influenced by experimental vegetation control measures, although additional work on other early-successional species will be useful to evaluate the generalities of our findings.
Near-ultraviolet light reduced Sandhill Crane collisions with a power line by 98%
Authors: Dwyer James F , Pandey Arun K , McHale Laura A , Harness Richard E
Published: July 2019

Midflight collisions with power lines impact 12 of the world’s 15 crane species, including 1 critically endangered species, 3 endangered species, and 5 vulnerable species. Power lines can be fitted with line markers to increase the visibility of wires to reduce collisions, but collisions can persist on marked power lines. For example, hundreds of Sandhill Cranes (Antigone canadensis) die annually in collisions with marked power lines at the Iain Nicolson Audubon Center at Rowe Sanctuary (Rowe), a major migratory stopover location near Gibbon, Nebraska. Mitigation success has been limited because most collisions occur nocturnally when line markers are least visible, even though roughly half the line markers present include glow-in-the-dark stickers. To evaluate an alternative mitigation strategy at Rowe, we used a randomized design to test collision mitigation effects of a pole-mounted near-ultraviolet light (UV-A; 380–395 nm) Avian Collision Avoidance System (ACAS) to illuminate a 258-m power line span crossing the Central Platte River. We observed 48 Sandhill Crane collisions and 217 dangerous flights of Sandhill Crane flocks during 19 nights when the ACAS was off, but just 1 collision and 39 dangerous flights during 19 nights when the ACAS was on. Thus, we documented a 98% decrease in collisions and an 82% decrease in dangerous flights when the ACAS was on. We also found a 32% decrease in the number of evasive maneuvers initiated within 25 m of the power line along the river, and a 71% increase in the number of evasive maneuvers initiated beyond 25 m when the ACAS was on. Sandhill Cranes reacted sooner and with more control, and experienced substantially fewer collisions, when the ACAS was on. Installation of the ACAS on other high-risk spans, and perhaps on other anthropogenic obstacles where birds collide, may offer a new solution to a long-running conservation dilemma.
Effects of climate change on the distributional potential of three range-restricted West African bird species
Authors: Freeman Benedictus , Sunnarborg Julia , Peterson A Townsend
Published: July 2019

A detailed understanding of species’ responses to global climate change provides an informative baseline for designing conservation strategies to optimize protection of biodiversity. However, such information is either limited or not available for many tropical species, making it difficult to incorporate climate change into conservation planning for most tropical species. Here, we used correlative ecological niche models to assess potential distributional responses of 3 range-restricted West African birds, Timneh Parrot (Pscittacus erithracus timneh), Ballman’s Malimbe (Malimbus ballmanni), and White-necked Rockfowl (Picathartes gymnocephalus), to global climate change. We used primary biodiversity occurrence records for each species obtained from the Global Biodiversity Information Facility, eBird, and VertNet; for environmental data, we used climatic variables for the present and future, the latter characterized by 2 IPCC representative concentration pathways (4.5, 8.5) future emissions scenarios and 27 general circulation models for a 2050 time horizon. We found broad present-day potential distributions with respect to climate for all 3 species. Future potential distributions for Ballman’s Malimbe and White-necked Rockfowl tended to be stable and closely similar to their present-day distributions; by contrast, we found marked climate change–driven potential range loss across the range of Timneh Parrot. Our results suggest that impacts of climate change on the present distributions of West African birds will in some cases be minimal, but that individual species may respond differently to future conditions. Thus, to optimize conservation of these species, and of bird diversity in general, we recommend that regional-to-national species conservation action plans incorporate climate change adaptation strategies for individual species; ecological niche models could provide an informative baseline information for this planning and prioritization.
Conservation implications of extraordinary Greater Scaup (Aythya marila) concentrations in the Odra Estuary, Poland
Authors: Marchowski Dominik , Leitner Michael
Published: July 2019

Human activities in marine coastal areas may coincide with protected areas for birds. Some of these anthropogenic activities may pose threats, such as gillnet fisheries, which can significantly affect populations of diving birds, especially gregarious species that gather in huge flocks in small areas such as Greater Scaup (Aythya marila). The Odra Estuary (Baltic Sea, Poland) is known for its importance as a wintering site for scaup; it is also used by fishermen using gillnets. Precise tools to determine the distribution and abundance of birds allow evaluation of risks faced by large aggregations. We used kernel density interpolation to estimate the spatial density of scaup in the Odra Estuary in spring 2011. At that time, an extraordinarily high number of scaup (95,400) was recorded, ~73% (63.0–94.5%) of the entire northwest European flyway population. Three variables are particularly important for conserving highly mobile long-distance migrating species: spatial distribution, abundance, and time (season of the year). This event concentrated most of the scaup flyway population in a small space, making the population vulnerable to mass mortality. We also show aggregated data of the spatial distribution of scaup during the 2015–2016 and 2016–2017 seasons to highlight differences in the spatial use of the area between seasons. Vast areas occupied by scaup in 2011 were not used during 2 other studied seasons; this spatial variation may be crucial in conservation planning of this species. Our results are a first step in documenting the spatial distribution of scaup in the Odra Estuary and identifying the potential area of overlap with fishing activity.
Associations of Hearing Loss and Menopausal Hormone Therapy With Change in Global Cognition and Incident Cognitive Impairment Among Postmenopausal Women
Authors: Armstrong Nicole M , Espeland Mark A , Chen Jiu-Chiuan , Masaki Kamal , Wactawski-Wende Jean , Li Wenjun , Gass Margery L S , Stefanick Marcia L , Manson JoAnn E , Deal Jennifer A , Rapp Stephen R , Lin Frank R , Resnick Susan M
Published: July 2019

Background

Hearing loss (HL) and menopausal hormone therapy (conjugated equine estrogens [CEE] and/or medroxyprogesterone acetate [MPA]) are separately associated with cognitive decline and increased risk of incident cognitive impairment. Joint effects of HL and HT could be associated with additive or synergistic decline in global cognition and risk of incident cognitive impairment among postmenopausal women.

Methods

Using the Women’s Health Initiative (WHI) Memory Study, 7,220 postmenopausal women with measures of HL, global cognition (Modified Mini-Mental State Examination score), and cognitive impairment (centrally adjudicated diagnoses of mild cognitive impairment and dementia) from 1996 to 2009. Multivariable linear mixed-effects models were used to analyze rate of change in global cognition. Accelerated failure time models were used to evaluate time to incident cognitive impairment, stratified by HT.

Results

Within the CEE-Alone trial, observed adverse effects of CEE-Alone on change in global cognition did not differ by HL, and estimated joint effects of HL and CEE-Alone were not associated with incident cognitive impairment. Within the CEE+MPA trial, while HL did not independently accelerate time to cognitive impairment, the adverse effect of CEE+MPA on global cognition was heightened in older women with HL. Older women on CEE+MPA either with HL (time ratio [TR] = 0.82, 95% confidence interval [CI]: 0.71, 0.94) or with normal hearing (TR = 0.86, 95% CI: 0.76, 0.97) had faster time to cognitive impairment than those with normal hearing and placebo.

Conclusions

HL may accentuate the adverse effect of CEE+MPA, not CEE-Alone, on global cognitive decline, not incident cognitive impairment, among postmenopausal women on HT.
Bad News, Declining Trust? Effects of Exposure to Economic News on Trust in the European Union
Authors: Brosius Anna , van Elsas Erika J , de Vreese Claes H
Published: July 2019

Evaluations of the economy are often assumed to be at the heart of citizens’ support for political systems. Despite being a vital source of information, we know little about how economic news coverage influences political support. The present study investigates how exposure to economic news coverage impacts trust in the European Union (EU), using a combination of automated content analysis data and nine-wave panel survey data between 2007 and 2016. We find that respondents exposed to more EU economic news lose confidence in the economy and trust in the EU. Yet, while exposure to negative EU economic news negatively affects economic confidence, it has a positive effect on trust in the EU. The opposite is the case for positive coverage.
The hypothesis of equal wave speeds for stabilization of Timoshenko beam is not necessary anymore: the time delay cases†
Authors: Almeida Júnior D S , Elishakoff I , Ramos A J A , Rosário Miranda L G
Published: July 2019

In the current study, we consider the Bresse–Timoshenko type systems and we prove some stability results for time delay cases into setting of so called simplified Bresse–Timoshenko equations (or truncated version of Bresse–Timoshenko equations) according to contributions of Elishakoff et al. (2010, Advances in Mathematical Modeling and Experimental Methods for Materials and Structures. Solid Mechanics and Its Applications. Springer: Berlin, 249–254.; 2015, Celebrating the Centenary of Timoshenko’s study of effects of shear deformation and rotary inertia. Appl. Mech. Rev.67, 1–11.; 2017, Critical contrasting of three versions of vibrating Bresse-Timoshenko beam with a crack. Int. J. Solids Struct. 109, 143–151.). These equations are free of the so-called ‘second spectrum’ phenomenon, and they have important consequences on stabilization setting. Specifically, following Almeida Júnior and Ramos (2017, On the nature of dissipative Timoshenko systems at light of the second spectrum. Z. Angew. Math. Phys.68, 31.) in a recent contribution that shows that damping effects eliminate the consequences of this spectrum for equal wave propagation velocities, we prove that time delay effects are able of stabilizing the truncated version regardless of any relationship between coefficients of system. It is concluded that dissipative truncated versions of Bresse–Timoshenko equations are advantageous over the classical Bresse–Timoshenko equations in stabilization context.
Performance and return to sport after hip arthroscopy for femoracetabular impingement syndrome in National Hockey League players
Authors: Sochacki Kyle R , Jack Robert A , Hirase Takashi , Vickery Justin , Harris Joshua D
Published: July 2019

Femoroacetabular impingement (FAI) syndrome is a common cause of hip pain in National Hockey League (NHL) players that may lead to decreased performance. The purpose of this study was to determine the (i) return to sport (RTS) rate in NHL players following hip arthroscopy for FAI, (ii) post-operative career length and games per season, (iii) pre- and post-operative performance and (iv) post-operative performance compared with control players. NHL athletes who underwent hip arthroscopy for FAI and matched controls were identified based on position, age (±1 year), years of experience (±1 year) and performance data prior to the surgery date. Demographic and performance data were collected. RTS was defined as playing in at least one NHL game after surgery. A Bonferroni correction was used to control for multiple comparisons with statistical significance defined by a P-value ≤ 0.007. Seventy players (77 surgeries) were analysed (mean age 29.4 ± 4.5 years; mean 8.8 ± 4.7 years NHL experience at the time of surgery). Sixty-three players (70 surgeries, 90.9%) RTS at an average of 6.8 ± 4.1 months. The 1-year NHL career survival rate for players undergoing surgery was 84.4%. Players in the control group (4.4 ± 2.7 years) had longer careers (P = 0.00002) than players that underwent surgery (3.3 ± 2.5 years). There was no significant (P > 0.007) decrease in post-operative performance compared with pre-operatively and with matched controls. The RTS rate for NHL athletes after hip arthroscopy for FAI is above 90% at less than 1 year. Following surgery, if a player returns to the NHL, then their post-operative performance is similar to pre-operatively and controls, but their careers are approximately one season less than controls.
Single-Item Versus Multiple-Item Headache Ratings in Service Members Seeking Treatment for Brain Injury
Authors: Lu Lisa H , Bowles Amy O , Kennedy Jan E , Eapen Blessen C , Cooper Douglas B
Published: July 2019

Introduction

Headaches are the most common complaint after traumatic brain injury (TBI) and a significant cause of morbidity and disability among military personnel. Currently, there are a several measures which can assess headache disability, but there is a significant burden to assess each individual symptom given this heterogeneous polymorbid population. The objective of this proposed study was to validate the single headache item from the Neurobehavioral Symptom Inventory (NSI) compared to the 6-item Headache Impact Test (HIT-6).

Materials and Methods

Participants included consecutive treatment-seeking outpatients at the Brain Injury Rehabilitation Service at the Brooke Army Medical Center from August 2007 to January 2010 who were administered a battery of assessment measures at initial intake, as part of usual care. Archival record review was conducted using procedures approved by the local Institutional Review Board. Inclusionary criteria included completion of both the HIT-6 and NSI. Participants with a cut-off score of >22 on the NSI Validity-10 were excluded in a post hoc analysis to validate findings among those who passed validity screen.

Results

The Pearson correlation between the single-item NSI headache measure and the HIT-6 revealed at least 64% shared variance in this military sample (r = 0.8, p < 0.001), indication a high association between the two measures.

Conclusion

The NSI single-item headache measure adequately captured headache severity in this military cohort. Use of the single-item NSI headache measure may minimize survey burden on participants whose primary complaint is not headaches, or who present with multiple symptoms. Future studies are needed to validate the single-item headache measure in other samples.
Preparing Future Medical Educators: Development and Pilot Evaluation of a Student-Led Medical Education Elective
Authors: Harvey Morgan M , Berkley Holly H , O’Malley Patrick G , Durning Steven J
Published: July 2019

Introduction

Although all medical school graduates are expected to be educators as residents, and subsequently as faculty, most students receive no formal education on how to teach. At the Uniformed Services University (USU), no formal educational training previously existed for senior medial students as they prepared for residency. A novel Medical Education Elective for MS4s was developed and run by MS4s with faculty mentoring at USU with implementation between January and June 2018.

Materials and Methods

The overall goal of the 4-week course was to provide a forum for MS4s to gain exposure to educational theories and teaching methods with an opportunity to practice learned skills in the underclass curriculum. The course’s three core components were: didactics, observed teaching, and independent teaching. The course was evaluated via multiple methods including verbal and survey feedback from both first and fourth year medical students.

Results

The preliminary outcomes revealed the course had a positive impact on both first-year medical students (MS1s) and MS4s. As of May 2018, 100% (n = 59) of MS1s surveyed reported that having an MS4 teacher contributed positively to their learning experience. All MS4s surveyed (n = 12) agreed that the course enhanced their confidence in teaching.

Conclusions

Medical education courses not only offer an opportunity for senior students to cultivate educational theoretical knowledge and teaching skills in preparation for residency but also contribute positively to the learning experiences of underclass students. Now that the elective has been piloted with initial data suggesting feasibility and benefit to both MS4 and MS1 students, the next steps are to focus on ensuring longevity of the course offering at USU and to consider working with senior students at other institutions that lack formal training in education to start similar student run medical education initiatives.
Transcriptome analyses of cells carrying the Type II Csp231I restriction–modification system reveal cross-talk between two unrelated transcription factors: C protein and the Rac prophage repressor
Authors: Negri Alessandro , Jąkalski Marcin , Szczuka Aleksandra , Pryszcz Leszek P , Mruk Iwona
Published: July 2019

Restriction-modification (R–M) systems represent an effective mechanism of defence against invading bacteriophages, and are widely spread among bacteria and archaea. In acquiring a Type II R–M system via horizontal gene transfer, the new hosts become more resistant to phage infection, through the action of a restriction endonuclease (REase), which recognizes and cleaves specific target DNAs. To protect the host cell's DNA, there is also a methyltransferase (MTase), which prevents DNA cleavage by the cognate REase. In some R–M systems, the host also accepts a cis-acting transcription factor (C protein), which regulates the counteracting activities of REase and MTase to avoid host self-restriction. Our study characterized the unexpected phenotype of Escherichia coli cells, which manifested as extensive cell filamentation triggered by acquiring the Csp231I R–M system from Citrobacter sp. Surprisingly, we found that the cell morphology defect was solely dependent on the C regulator. Our transcriptome analysis supported by in vivo and in vitro assays showed that C protein directly silenced the expression of the RacR repressor to affect the Rac prophage-related genes. The rac locus ydaST genes, when derepressed, exerted a toxicity indicated by cell filamentation through an unknown mechanism. These results provide an apparent example of transcription factor cross-talk, which can have significant consequences for the host, and may represent a constraint on lateral gene transfer.
A Unique Case of Microvascular Triple Decompression for Combined Simultaneous Trigeminal Neuralgia, Hemifacial Spasm, and Glossopharyngeal Neuralgia Because of the Dolichoectatic Vertebrobasilar System
Authors: Perez-Roman Roberto J , Chen Stephanie H , Sur Samir , Leon-Correa Roberto , Morcos Jacques J
Published: July 2019

BACKGROUND

Trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN) are hyperactive dysfunction syndromes (HDS) commonly caused by microvascular compression of their root entry zone. Cases of combined HDS involving 2 or more of these entities are extremely rare. Although microvascular decompression is the surgical treatment of choice, there are additional techniques that have been described as efficient methods to accomplish vessel transposition.

OBJECTIVE

To our knowledge, we present the first reported case of triple simultaneous HDS successfully treated using the clip-sling technique to achieve microvascular decompression. We discuss several technical pearls and pitfalls relevant to the use of the sling suspension technique.

METHODS

We report the rare case of a 66-yr-old male with combined simultaneous unilateral right-sided TN, HFS, and GPN because of a dolichoectatic vertebrobasilar system compressing the exit zones of the right trigeminal, facial, and glossopharyngeal nerves and present a literature review of combined HDS and their different surgical treatments.

RESULTS

Symptomatic TN, HFS, and GPN have been reported 8 times in the literature with our case being the ninth. A retrosigmoid craniotomy was performed for microvascular decompression of the brainstem with a clip-sling suspension technique augmented with Teflon felt pledgets. The patient had immediate complete relief from TN, HFS, and GPN postoperatively.

CONCLUSION

Microvascular decompression using the clip-sling technique via a retrosigmoid approach should be considered as a safe and effective option for transposition and suspension of the offending artery and decompression of the affected nerve roots in cases of combined HDS.
DNA Damage and Perturbed Topoisomerase IIα as a Target of 1,4-Benzoquinone Toxicity in Murine Fetal Liver Cells
Authors: Holmes Trent H , Winn Louise M
Published: July 2019

Benzene is a ubiquitous environmental pollutant. Recent studies have shown a link between the development of childhood leukemias and maternal benzene exposure, suggesting that these leukemias may be initiated in utero. Benzene crosses the placental barrier however the mechanisms behind in utero benzene toxicity have not been well elucidated. This study is the first to show that the benzene metabolite, benzoquinone (BQ), perturbs fetal topoisomerase IIα (Topo IIα), an enzyme essential for DNA repair. Using cultured murine CD-1 fetal liver cells, this study shows that Topo IIα activity decreases following 24 h of exposure to BQ (12.5 and 15.625 µM), with 12.5 µM confirmed to disrupt the c-kit+ Lin− Sca-1− Il7rα− population of cells in culture. Pretreatment with the antioxidant N-acetylcysteine did not prevent the inhibition of Topo IIα by BQ. An increase in Topo IIα-DNA covalent adducts was detected following 24-h exposure to BQ (12.5 and 50 µM). Interestingly, BQ (12.5 µM) exposure did not significantly increase levels of 4-hydroxynonenal (4-HNE), a marker of oxidative stress after 24 h. However, increased levels of the double-stranded DNA break marker γH2AX were detected following 24 h of BQ exposure, confirming that Topo IIα-induced breaks are increased in BQ-treated cells. This study shows that fetal Topo IIα is perturbed by BQ and suggests that this protein is a target of benzene and may be implicated with in utero benzene toxicity.
Development and Validation of an Instrument to Measure Transformation From Study Abroad
Authors: Foronda Cynthia , Phitwong Ame
Published: July 2019

Study abroad has the potential to lead to perspective transformation, the highest level of learning. Instruments are lacking to quantitatively measure the effectiveness of the study abroad experience in terms of student learning outcomes. Obtaining such data could be used to better evaluate teaching methods. Informed by qualitative research, an instrument was developed to measure transformation from study abroad. The scale content validity index was 0.82, demonstrating strong validity. Although further testing is needed, this instrument presents a way to examine the impact of study abroad so that learners may be better prepared to attend to the global community.
Hypoxemia, Bradycardia, and Multiple Laryngoscopy Attempts during Anesthetic Induction in Infants
Authors: Gálvez Jorge A. , Acquah Samuel , Ahumada Luis , Cai Lingyu , Polanski Marcia , Wu Lezhou , Simpao Allan F. , Tan Jonathan M. , Wasey Jack , Fiadjoe John E.
Published: July 2019

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

The infant airway is particularly vulnerable to trauma from repeated laryngoscopy attempts. Complications associated with elective tracheal intubations in anesthetized infants may be underappreciated. We conducted this study of anesthetized infants to determine the incidence of multiple laryngoscopy attempts during routine tracheal intubation and assess the association of laryngoscopy attempts with hypoxemia and bradycardia.

Methods

We conducted a retrospective cross-sectional cohort study of anesthetized infants (age less than or equal to 12 months) who underwent direct laryngoscopy for oral endotracheal intubation between January 24, 2015, and August 1, 2016. We excluded patients with a history of difficult intubation and emergency procedures. Our primary outcome was the incidence of hypoxemia or bradycardia during induction of anesthesia. We evaluated the relationship between laryngoscopy attempts and our primary outcome, adjusting for age, weight, American Society of Anesthesiologists status, staffing model, and encounter location.

Results

A total of 1,341 patients met our inclusion criteria, and 16% (n = 208) had multiple laryngoscopy attempts. The incidence of hypoxemia was 35% (n = 469) and bradycardia was 8.9% (n = 119). Hypoxemia and bradycardia occurred in 3.7% (n = 50) of patients. Multiple laryngoscopy attempts were associated with an increased risk of hypoxemia (adjusted odds ratio: 1.78, 95% CI: 1.30 to 2.43, P < 0.001). There was no association between multiple laryngoscopy attempts and bradycardia (adjusted odds ratio: 1.23, 95% CI: 0.74 to 2.03, P = 0.255).

Conclusions

In a quaternary academic center, healthy infants undergoing routine tracheal intubations had a high incidence of multiple laryngoscopy attempts and associated hypoxemia episodes.
Musings from an Unlikely Clinician–Scientist
Authors: Orser Beverley A.
Published: July 2019

This article, which stems from the 2018 American Society of Anesthesiologists Excellence in Research Award Lecture, aims to encourage young investigators, offer advice, and share several early life experiences that have influenced the author’s career as an anesthesiologist and clinician–scientist. The article also describes key discoveries that have increased understanding of the role of γ-aminobutyric acid type A (GABAA) receptors in health and disease. The author’s research team identified the unique pharmacologic properties of extrasynaptic GABAA receptors and their role in the anesthetic state. The author’s team also showed that extrasynaptic GABAA receptors expressed in neuronal and nonneuronal cells contribute to a variety of disorders and are novel drug targets. The author’s overarching message is that young investigators must create their own unique narratives, train hard, be relentless in their studies and—most important—enjoy the journey of discovering new truths that will ultimately benefit patients.
What Are the Effects of the Maternal Voice on Preterm Infants in the NICU?
Authors: Williamson Selena , McGrath Jacqueline M.
Published: July 2019

Background/Significance:

Premature infants often experience extended stays in the neonatal intensive care unit (NICU) as opposed to home with parents. This prolonged separation creates a strain for both parents and infants, decreasing attachment and parental caregiving. One strategy to combat this shared stress is increasing parental participation, particularly through the use of their voices whether parents are present or not.

Purpose:

This Evidence-Based Practice Brief column explores the connection between mother and child, specifically the effects of maternal voice on infant autonomic stability, weight gain, and behavioral states.

Methods:

A systematic search of CINAHL, PubMed, and PsycInfo was used to identify studies involving the use of maternal voice intervention with preterm infants in the NICU.

Results:

Fifteen studies were identified. Three intervention categories emerged: (1) live maternal speech, (2) recorded maternal speech (subcategories included whether intervention content was prescribed or not), and (3) recorded maternal speech that was combined with biological maternal sounds (heart rate). Within each category, studies were organized chronologically to reflect how knowledge has changed overtime.

Implications for Practice:

Maternal voice has physiological as well as behavioral and emotional effect on preterm infants. Several studies found that maternal voice increased autonomic stability improving (heart rate and respirations) as well as weight gain. No negative effects were identified. Given these findings, incorporating different types of maternal voice into routine care by the bedside nurse can assist the mother in feeling more involved in her infant's care without seemingly being a distraction or obstacle to providers.

Implications for Research:

A major limitation for generalizability was sample size; more research is needed with larger sample sizes replicating interventions types to discern best outcomes.

Video Abstractavailable at https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?videoId=31&autoPlay=true.
Biomechanical Analysis of Instability in Rotational Distal Fibula Fractures (OTA/AO 44-B1) With an Intact Deltoid Ligament
Authors: Hempen Eric , Butler Bennet , Barbosa Mauricio , Muriuki Muturi , Havey Robert , Kadakia Anish
Published: July 2019

Objectives:

To biomechanically analyze instability in supination external rotation (SER) II/III patterns.

Methods:

Nineteen cadaver legs were tested in a mechanical jig. One, 2, 3, and 4 Nm of external rotation were applied to intact ankles, SER II injuries, and SER III injuries. The talar position relative to the tibia was recorded using 3D motion tracking. Change from the unloaded state in each condition and the torque level was calculated. Results were analyzed using analysis of variance with post hoc paired t tests.

Results:

SER II showed statistically significant differences from the intact state with coronal translation (2, 3, and 4 Nm), sagittal translation (1 and 2 Nm), axial rotation (1, 2, 3, and 4 Nm), and coronal rotation (3 and 4 Nm). SER III showed statistically significant differences from the intact state with coronal translation (2, 3, and 4 Nm), sagittal translation (1, 2, and 3 Nm), axial rotation (1, 2, 3, and 4 Nm), and coronal rotation (3 and 4 Nm). SER II and SER III differed significantly from each other with coronal translation (1, 2, and 3 Nm), axial rotation (2, 3, and 4 Nm), and coronal rotation (1, 3, and 4 Nm).

Conclusion:

Instability in SER injuries has only been described with coronal translation and suggests that deltoid rupture is necessary. Our data demonstrate instability in SER II/III in sagittal translation and axial rotation as well as subtle instability in coronal translation. The clinical impact is unclear, but better understanding of long-term sequelae of this instability is needed.
Approaches for vulnerable and frail older patients with diffuse large B-cell lymphomas
Authors: Soubeyran Pierre-Louis , Cordoba Raul
Published: July 2019

Purpose of review

The current review will outline recent data which may improve management of older patients with aggressive lymphoma through comanagement by hematologists and geriatricians.

Recent findings

Many recent data show that determinants of prognosis differ in older patients with an increased importance of nonlymphoma-related parameters. As a consequence, geriatric assessment parameters are predictive of the outcome in these patients. Data from clinical trials allow for standardization of chemotherapy in diffuse large B-cell lymphoma even in older fit patients. Yet data are missing in vulnerable and frail patients. Recent results show that anthracyclines appear essential also in vulnerable patients although precautions should be considered. Geriatric intervention will be the next step but its potential value remains to be demonstrated.

Although aggressive lymphoma therapy is well standardized, management of vulnerable and frail patients remains complicated because of the accumulation of comorbidities and geriatric syndromes and because they are excluded from clinical trials. Comanagement with hematologists and geriatricians may be the solution to improve outcome but organization of care should reinvented.
Clinical Utility of a Blood-based Protein Assay on Diagnostic Colonoscopy Referrals for Elevated-risk Colorectal Cancer Patients in Primary Care
Authors: Peabody John , Rahim Arshad , Wilcox Bruce , McGehee Carrie , Estigarribia Erwin , Paculdo David , Arzadon Aislinn , Fugaro Steven , Tran Mary , Spitzer Gary
Published: July 2019

Background:

Colonoscopies are effective in finding early stage colorectal cancer (CRC), which when found in a timely manner, dramatically improve survival rates. A significant number of at-risk patients are still not screened. We investigated the utility of a blood-based protein assay to assess for CRC in patients with elevated risk on the quality of preventive care delivered by board-certified primary care physicians (PCPs) in the United States.

Methods:

We report on the results of a 3-part, longitudinal, randomized controlled trial. Part 1 assessed physicians’ ability to identify simulated patients at risk for CRC and found PCPs missed colonoscopy referrals for high-risk patients ~40% of the time. Part 2 randomized PCPs into control and intervention arms and demonstrated that a novel blood-based protein assay increased referral rates for a diagnostic colonoscopy when caring for simulated patients. Part 3, reported herein, compares real-world colonoscopy rates of actual patients cared for by control versus intervention physicians. Part 3 was executed to confirm whether the use of the assay demonstrated the same utility in their real world, high-risk patients as found in part 2 using simulated patients.

Results:

In the simulations, physicians with access to the assay were significantly more likely to order diagnostic colonoscopies. Similarly, in real-world practice, patients were also more likely to be referred for a diagnostic colonoscopy (odds ratio, 4.57; 95% confidence interval, 1.19-17.57).

Conclusions:

An increase in CRC risk, as indicated by the assay in simulated and real-life patients, was associated with a higher likelihood of appropriate patients being referred to diagnostic colonoscopy.
The Impact of Serum Glucose in the Treatment of Locoregionally Advanced Pancreatic Cancer
Authors: Iarrobino Nick A. , Gill Beant S. , Klement Rainer J. , Bernard Mark E. , Champ Colin E.
Published: July 2019

Introduction:

Studies have consistently identified an increased risk of pancreatic cancer in diabetics, yet the role hyperglycemia may play in predicting prognosis is less clear. This work aims to evaluate the impact of glycemic state and antidiabetics on outcomes after systemic and local treatment for locoregionally advanced pancreatic cancer.

Materials and Methods:

This retrospective study consisted of 303 patients with newly diagnosed advanced-stage pancreatic cancer treated from 2004 to 2014. Kaplan-Meier survival analysis method was used to estimate time to event for overall survival, distant metastasis, and locoregional control. Blood glucose values (n=8599) were assessed both as continuous and categorical variables in univariate and multivariable Cox proportional hazard regression models to estimate hazard ratios (HRs) and identify independent prognostic factors. A 6-month conditional landmark analysis excluding patients with <6 months follow-up or survival was conducted.

Results:

Median follow-up and survival was 18.1 and 18.4 months, respectively. On univariate analysis, maximum pretreatment glucose value was associated with reduced overall survival (HR 1.005, P=0.023) and locoregional control (HR 1.001, P=0.001). A pretreatment glucose value ≥200 mg/dL was associated with increased mortality in multivariable analysis (adjusted HR 1.01, P=0.015). After conditional analysis, glucose ≥200 mg/dL before local treatment was associated with reduced overall survival (adjusted HR 1.562; 95% confidence interval [CI], 1.16-2.11; P=0.003).

Conclusions:

Elevated blood glucose before treatment of locoregionally advanced pancreatic cancer was associated with poorer outcomes. These findings should be incorporated in future clinical trial design.
An Albumin-Bilirubin (ALBI) Grade–based Prognostic Model For Patients With Hepatocellular Carcinoma Within Milan Criteria
Authors: Ho Shu-Yein , Liu Po-Hong , Hsu Chia-Yang , Hsia Cheng-Yuan , Su Chien-Wei , Huang Yi-Hsiang , Lei Hao-Jan , He Yi-Jhen , Hou Ming-Chih , Huo Teh-Ia
Published: July 2019

Objective:

The Milan criteria are recommended as the major reference for liver transplantation in patients with small hepatocellular carcinoma (HCC). However, alternative anticancer treatments are often utilized due to severe donor organ shortage. This study aimed to develop and validate an albumin-bilirubin (ALBI) grade–based prognostic model to stratify survival in patients within Milan criteria undergoing nontransplant therapy.

Patients and Methods:

A total of 1655 patients were assigned into the derivation and validation cohort according to treatment modalities. Multivariate analysis was used to identify independent predictors of survival in the derivation cohort. An ALBI-based model was evaluated in the validation cohort.

Results:

In the Cox multivariate model, age 65 years or older (hazard ratio [HR]=1.576,P<0.001), serum α-fetoprotein (AFP) level >100 ng/mL (HR=1.671,P<0.001), ascites (HR=1.808,P<0.001), performance status 1 to 4 (HR=1.738,P<0.001), ALBI grade 2 (HR=1.827,P<0.001), and ALBI grade 3 (HR=3.589,P<0.001) were independent predictors of poor survival in the derivation cohort. An ALBI-based prognostic model with a total of 0 to 6 points was derived with the sum of 5 variables: 1 point each for age 65 years or older, AFP >100 ng/mL, presence of ascites, performance status 1 to 4, and ALBI grade 2, and 2 points for ALBI grade 3. This model can accurately predict long-term outcome in the validation cohort (P<0.001) and discriminate survival in patients stratified by curative and noncurative treatments (bothP<0.001).

Conclusion:

The proposed ALBI grade–based model is feasible in predicting survival in HCC patients within the Milan criteria, and helps identify high-risk patients who need timely liver transplantation.
PD-L1 Detection—Pearls and Pitfalls Associated With Current Methodologies Focusing on Entities Relevant to Dermatopathology
Authors: Oh Kei Shing , Mahalingam Meera
Published: July 2019

PD-L1 is a transmembrane glycoprotein with an extracellular as well as an intracellular cytoplasmic domain. Physiologically, it plays a pivotal role in regulating T-cell activation and tolerance. Many tumor cells have exploited this regulatory mechanism by overexpressing PD-L1 in an effort to escape immunologic surveillance. In this review, we parse the literature regarding the prognostic value of tumoral PD-L1 expression before discussing the various methodologies as well as the pearls and pitfalls associated with each for predicting response to anti–PD-1/PD-L1 therapies. Special attention is given to cutaneous entities in which PD-L1 expression has been documented with an emphasis on cutaneous malignancies that have seen the broadest applications of anti–PD-L1/PD-1 therapies. Currently, immunohistochemistry is the method that is most commonly used for detection of PD-L1. However, with the wide array of immunohistochemistry protocols and staining platforms available in the market, there seems to be different cutoffs not just for different entities but also for the same entity. This review is an attempt to address the need for standardization and validation of existing protocols for PD-L1 detection.