bluuebunny/crossref_metadata_2025 huggingface dataset:
Supporting Resident Research Learning in the Workplace: A Rapid Realist Review
Authors: Noble Christy , Billett Stephen R. , Phang Dana T.Y. , Sharma Siddharth , Hashem Fahid , Rogers Gary D.
Published: August 2018

Purpose

Residents are increasingly expected to engage in practice-based research; however, engagement in research whilst also fulfilling clinical duties is often challenging. Evidence suggests that residents require specific developmental experiences, along with clinical practice, to become effective researchers. The authors therefore conducted a rapid realist review to explore strategies and key mechanisms supporting effective resident research activities in clinical settings. They examined relationships amongst different clinical contexts, learning mechanisms, and research engagement outcomes to provide evidence-based, theory-informed recommendations for improving resident research engagement and extending understandings of workplace learning in health care settings.

Method

In 2015–2016, the authors used a rapid realist methodology informed by workplace learning theory to review international literature published between January 2005 and December 2015. The review drew upon sources from OVID Medline, ERIC, Embase, and AustHealth. The authors screened articles for eligibility using inclusion criteria and appraised articles using realist review quality criteria.

Results

The authors included 51 articles in the review. The review process identified three key mechanisms for effective integration and support of resident research engagement, as informed by workplace learning theory: (1) opportunities to engage in practice-informed research supported by longitudinal curricula, (2) guidance by clinician–researchers, and (3) assessing residents’ research readiness and promoting their intentionality for engagement.

Conclusions

This review extends existing literature and informs workplace-based research engagement strategies for residents whilst demonstrating the applicability of workplace learning theory to improving residents’ research engagement. The authors propose a learning model to support effective resident research engagement through clinical practice.
Narrative Intersectionality in Caring for Marginalized or Disadvantaged Patients: Thinking Beyond Categories in Medical Education and Care
Authors: Blackie Michael , Wear Delese , Zarconi Joseph
Published: August 2018

Categories are essential to doctors’ thinking and reasoning about their patients. Much of the clinical categorization learned in medical school serves useful purposes, but an extensive literature exists on students’ reliance on broad systems of social categorization. In this article, the authors challenge some of the orthodoxies of categorization by combining narrative approaches to medical practice with the theoretical term “intersectionality” to draw students’ attention to the important intersecting, but often overlooked, identities of their patients. Although intersectionality applies for all patients, the focus here is on its importance in understanding and caring for marginalized or disadvantaged persons.

Intersectionality posits that understanding individual lives requires looking beyond categories of identity in isolation and instead considering them at their intersection, where interrelated systems of power and oppression, advantage and discrimination are at play and determine access to social and material necessities of life. Combined with narrative approaches that emphasize the singularity of a person’s story, narrative intersectionality can enable a more robust understanding of how injustice and inequality interrelate multidimensionally to produce social disadvantage.

The authors apply this framework to two films that present characters whose lives are made up of numerous and often-contradictory identities to highlight what physicians may be overlooking in the care of patients. If the education of physicians encourages synthesis and categorization aimed at the critically useful process of making clinical “assessments” and “plans,” then there must also be emphasis in their education on what might be missing from that process.
Changes in Physicians’ Intrapersonal Empathy After a Communication Skills Training in Japan
Authors: Yamada Yu , Fujimori Maiko , Shirai Yuki , Ninomiya Hitomi , Oka Takakazu , Uchitomi Yosuke
Published: August 2018

Purpose

To investigate whether physicians’ intrapersonal empathy increased after a communication skills training (CST) workshop.

Method

Participants were oncologists from across Japan with three or more years of clinical experience in oncology. They were recruited through the Internet and via direct contact by the workshop organizers. Participants attended 1 of 132 two-day CST workshops, held between November 2007 and March 2011. Prior to the workshop (baseline/T1), participants completed a survey with demographic questions, the Jefferson Scale of Physician Empathy (JSPE), and the Interpersonal Reactivity Index (IRI). The JSPE was administered again immediately after completion of the workshop (follow-up/T2). Then the JSPE and IRI were administered as part of a three-month follow-up (T3) survey. Changes in participants’ mean total JSPE scores, JSPE subscale scores, and IRI subscale scores were compared using multivariate analysis of variance.

Results

Of the 507 workshop participants who received the three-month follow-up survey, 383 responded (response rate: 75.5%). Total JSPE scores and JSPE subscale scores at T2 and T3 were significantly higher than those at T1 (P < .01). IRI-Perspective Taking and IRI-Empathic Concern subscale scores increased significantly from T1 to T3 (P < .01), whereas IRI-Fantasy and IRI-Personal Distress subscale scores showed no significant changes. The JSPE scores of palliative care physician participants were significantly higher than those of medical oncologist participants at T1 and T3. No signifi cant differences were found by specialty at T2.

Conclusions

The intrapersonal empathy of oncologists in Japan increased after a two-day CST workshop.
Alpha 2-Macroglobulin as Dual Regulator for Both Anabolism and Catabolism in the Cartilaginous Endplate of Intervertebral Disc
Authors: Huang Bao , Chen Jian , Zhang Xuyang , Wang Jiasheng , Zheng Zeyu , Shan Zhi , Liu Junhui , Zhu Zhihai , Zhao Fengdong
Published: August 2018

Study Design.

Basic science study.

Objective.

To illustrate supplemental alpha-2 macroglobulin (α2 M) has beneficial effects on cartilaginous endplates (CEPs) that may slow the progression of intervertebral disc (IVD) degeneration.

Summary of Background Data.

CEPs play a vital role in progression of intervertebral disc degenerative diseases. However, the ideal and economic therapies for CEPs degeneration are still urgently required.

Methods.

Firstly, we confirmed degenerative CEP characters by H&E and Safranin O fast green staining and detected increasing level of α2 M and matrix metalloproteinase 13(MMP-13) in degenerative CEP by immunohistochemistry. Then, effects of exogenous α2 M on tumor necrosis factor alpha (TNF-α)-induced CEP catabolic enzyme and anabolic molecules were evaluated by qRT-PCR, Western blotting and ELISA in cultured CEP cells obtained from rats. Furthermore, suppression of α2 M on TNF-α-induced activation of NF-кB signaling pathway was measured by Western blotting and immunofluorescence. In addition, function of α2 M on TNF-α-treated ex vivo IVDs from rats lumbar IVDs was estimated by measuring the expression of MMP-13, Sox9, aggrecan, and type II collagen in CEP area.

Results.

Compared with normal CEP, level of α2 M was slightly increased in CEP from degenerative patients, whereas MMP-13 was sharply elevated. In vitro, α2 M inhibited expression and activity of MMP-3 or MMP-13 in a dose-dependent manner in rat CEP cells stimulated by TNF-α. The α2 M refrained phosphorylation of IκBα and inhibited nuclear translocation of p65. Finally, supplemental α2 M reduced expression of MMP-13, and promoted expression of Sox9, aggrecan, and type II collagen in CEP area of ex vivo IVDs cultured with TNF-α.

Conclusion.

α2 M is not sufficiently produced to inactivate higher concentrations of catabolic factor MMP-13 found in the degenerated CEP. Supplemental α2 M protects against the progression of IVD degeneration by inhibiting effects of proinflammatory cytokines.

Level of Evidence: N/A
Ultrasound Assessment of the Change in Carotid Corrected Flow Time in Fluid Responsiveness in Undifferentiated Shock
Authors: Barjaktarevic Igor , Toppen William E. , Hu Scott , Aquije Montoya Elizabeth , Ong Stephanie , Buhr Russell , David Ian J. , Wang Tisha , Rezayat Talayeh , Chang Steven Y. , Elashoff David , Markovic Daniela , Berlin David , Cannesson Maxime
Published: August 2018

Objectives:

Adequate assessment of fluid responsiveness in shock necessitates correct interpretation of hemodynamic changes induced by preload challenge. This study evaluates the accuracy of point-of-care Doppler ultrasound assessment of the change in carotid corrected flow time induced by a passive leg raise maneuver as a predictor of fluid responsiveness. Noninvasive cardiac output monitoring (NICOM, Cheetah Medical, Newton Center, MA) system based on a bioreactance method was used.

Design:

Prospective, noninterventional study.

Setting:

ICU at a large academic center.

Patients:

Patients with new, undifferentiated shock, and vasopressor requirements despite fluid resuscitation were included. Patients with significant cardiac disease and conditions that precluded adequate passive leg raising were excluded.

Interventions:

Carotid corrected flow time was measured via ultrasound before and after a passive leg raise maneuver. Predicted fluid responsiveness was defined as greater than 10% increase in stroke volume on noninvasive cardiac output monitoring following passive leg raise. Images and measurements were reanalyzed by a second, blinded physician. The accuracy of change in carotid corrected flow time to predict fluid responsiveness was evaluated using receiver operating characteristic analysis.

Measurements and Main Results:

Seventy-seven subjects were enrolled with 54 (70.1%) classified as fluid responders by noninvasive cardiac output monitoring. The average change in carotid corrected flow time after passive leg raise for fluid responders was 14.1 ± 18.7 ms versus –4.0 ± 8 ms for nonresponders (p < 0.001). Receiver operating characteristic analysis demonstrated that change in carotid corrected flow time is an accurate predictor of fluid responsiveness status (area under the curve, 0.88; 95% CI, 0.80–0.96) and a 7 ms increase in carotid corrected flow time post passive leg raise was shown to have a 97% positive predictive value and 82% accuracy in detecting fluid responsiveness using noninvasive cardiac output monitoring as a reference standard. Mechanical ventilation, respiratory rate, and high positive end-expiratory pressure had no significant impact on test performance. Post hoc blinded evaluation of bedside acquired measurements demonstrated agreement between evaluators.

Conclusions:

Change in carotid corrected flow time can predict fluid responsiveness status after a passive leg raise maneuver. Using point-of-care ultrasound to assess change in carotid corrected flow time is an acceptable and reproducible method for noninvasive identification of fluid responsiveness in critically ill patients with undifferentiated shock.
Achieving IHI's Triple Aim by Utilizing Core Health Program With Community Health Workers in Rural Communities
Authors: Fawcett Kenneth J. , Neff Raymond K. , Freese Decker Christina M. , Faber Josephine E.
Published: August 2018

Utilizing a nurse/community health worker team model, a Midwest institution's community health care division developed a 12-month managed care program for underserved individuals diagnosed with heart failure and/or diabetes. A study of 277 patients was conducted to determine whether this model could be utilized in rural settings. The program was evaluated using the Institute for Healthcare Improvement's Triple Aim criteria; HEDIS measures and other health indicators quantified each patient's performance. Study participants showed improved outcomes and a reduction in the total cost of care. Hospital admissions decreased (203.4 inpatient days were saved), and the return-on-investment value realized was 1.37 for emergency department and inpatient visits in the rural communities.
The Relationship Between Country of Origin and Prenatal Care Among Unauthorized Mexican and Guatemalan Immigrants
Authors: Held Mary Lehman , Lindley Lisa C.
Published: August 2018

This study examined how country of origin (Mexico or Guatemala) correlates with prenatal care utilization among unauthorized Latina immigrants, who encounter disparate access to health care. Logistic regression and negative binomial regression analyses were used to examine prenatal care adequacy and number of visits among a sample of 4188 unauthorized Latina immigrants. Findings suggest that originating from Guatemala predicted increased likelihood of inadequate prenatal care and fewer prenatal care visits. Implications can inform policy and practice to strengthen prenatal care utilization, especially for unauthorized Guatemalan immigrants. Future research should examine independent predictors of prenatal care for Mexican and Guatemalan women.
PHENOTYPIC VARIABILITY OF RECESSIVE RDH12-ASSOCIATED RETINAL DYSTROPHY
Authors: Zou Xuan , Fu Qing , Fang Sha , Li Hui , Ge Zhongqi , Yang Lizhu , Xu Mingchu , Sun Zixi , Li Huajin , Li Yumei , Dong Fangtian , Chen Rui , Sui Ruifang
Published: August 2018

Purpose:

To characterize the phenotypic variability and report the genetic defects in a cohort of Chinese patients with biallelic variants of the retinol dehydrogenase 12 (RDH12) gene.

Methods:

The study included 38 patients from 38 unrelated families with biallelic pathogenic RDH12 variants. Systematic next-generation sequencing data analysis, Sanger sequencing validation, and segregation analysis were used to identify the pathogenic mutations. Detailed ophthalmic examinations, including electroretinogram, fundus photography, fundus autofluorescence and optical coherence tomography, and statistical analysis were performed to evaluate phenotype variability.

Results:

Twenty-five different mutations of RDH12 were identified in the 38 families. Six of these variants were novel. Val146Asp was observed at the highest frequency (23.7%), and it was followed by Arg62Ter (14.5%) and Thr49Met (9.2%). Twenty-three probands were diagnosed with early-onset severe retinal dystrophy, 6 with Leber congenital amaurosis, 7 with autosomal recessive retinitis pigmentosa, and 2 with cone-rod dystrophy. Self-reported nyctalopia occurred in about a half of patients (55.3%) and was significantly more common among older patients (P < 0.01). Nyctalopia was not significantly associated with best-corrected visual acuity (P = 0.72), but older patients had significantly greater best-corrected visual acuity loss (P < 0.01). Only 15.8% of the patients had nystagmus, which was significantly more likely to occur among 36.8% of the patients with hyperopia >3D (P < 0.01) and/or in cases of reduced best-corrected visual acuity (P = 0.01), but was not associated with age (P = 0.87).

Conclusion:

Several high-frequency RDH12 variants were identified in patients with inherited retinal dystrophies, most of which were missense mutations. Variable but characteristic phenotypes of a progressive nature was observed. Overall, the findings indicated that biallelic RDH12 mutations are a common cause of early-onset retinal dystrophy and a rare cause of cone-rod dystrophy.
Clinical and Magnetic Resonance Imaging Characteristics of Postfenestration Optic Nerve Sheath Pseudomeningoceles
Authors: Rafailov Leon , Rubinstein Daniel , Wladis Edward J. , Mirani Neena , Frohman Larry P. , Langer Paul D. , Turbin Roger E.
Published: August 2018

Purpose:

The clinical significance of postoperative pseudomeningocele formation following optic nerve sheath fenestration (ONSF) has not been fully characterized. A literature review identifies 9 previously published cases the authors believe demonstrate pseudomeningocele formation and approximately 19 other similar findings that were either transient or less defined blebs. This study was undertaken to more clearly define the clinical, radiographic, and histopathologic features associated with this entity.

Methods:

Sixteen-year, single-center, retrospective chart review of all ONSF cases performed by 2 surgeons. Clinical data, intracranial pressure, radiographic imaging, and histopathology of clinically detected pseudomeningoceles after ONSF were reviewed.

Results:

Eighty-six eyes in 57 patients underwent ONSF (28 unilateral, 12 bilateral sequential, 17 bilateral simultaneous). Forty-nine of 57 patients had elevated intracranial pressure preoperatively (41 idiopathic intracranial hypertension, 4 venous thrombosis, 2 meningitis, 1 arteriovenous malformation, and 1 sarcoid). In 32 patients undergoing postoperative imaging, 4 eyes (4.7%) in 4 patients developed well-defined pseudomeningoceles, of which 3 were symptomatic and 2 required surgical revision. Each pseudomeningocele developed in the setting of elevated preoperative intracranial pressure (350, 360, 430, 500 mm H20). Magnetic resonance imaging and/or computed tomography revealed sharply demarcated fluid-filled sacs adjacent to the optic nerve. The contents of these sacs were hypointense on T1-weighted imaging, hyperintense on T2-weighting, variably enhanced with contrast, and hypointense on fluid attenuated inversion recovery, and were thus consistent with cerebrospinal fluid. Histopathologic analysis of one of these outpouchings demonstrated an acellular, fibrocollagenized lining consistent with pseudomeningocele. Three eyes in 3 additional patients had less well-defined findings on imaging interpreted as bleb-like or cyst-like change.

Conclusions:

Pseudomeningoceles following ONSF may be asymptomatic or may cause symptomatic orbital mass effect and rarely visual loss, amendable to surgical excision. Post-ONSF pseudomeningoceles are identified on computed tomography or magnetic resonance imaging to occur at the locations of fenestration sites and contain cerebrospinal fluid communicating with the subdural space that may act as a “filtration” bleb in some cases. Imaging findings may represent a spectrum spanning intraorbital cerebrospinal fluid leakage, partial walling off of bleb, or fully developed cysts. Resection of optic nerve pseudomeningoceles is considered in symptomatic cysts or eyes with papilledema that fails to improve.
Phase I Trial Evaluating the Safety of Preoperative Gemcitabine/nab-Paclitaxel With Concurrent Radiation Therapy for Borderline Resectable Pancreatic Cancer
Authors: Takahashi Hidenori , Akita Hirofumi , Ioka Tatsuya , Wada Hiroshi , Tomokoni Akira , Asukai Kei , Ohue Masayuki , Yano Masahiko , Ishikawa Osamu
Published: August 2018

Objectives

The objectives of this study were to assess the feasibility of preoperative gemcitabine/nab-paclitaxel–based chemoradiation therapy (CRT) for patients with borderline resectable pancreatic cancer (BRPC), which consists of induction chemotherapy and subsequent CRT, and to determine the recommended dose (RD) of gemcitabine/nab-paclitaxel with concurrent radiation therapy in a phase I trial.

Methods

Patients with BRPC received gemcitabine (1000 mg/m2)/nab-paclitaxel (125 mg/m2) on days 1, 8, and 15 during each 4-week cycle, which was repeated for 2 cycles as induction chemotherapy. After induction chemotherapy, the patients received gemcitabine/nab-paclitaxel with concurrent radiation therapy. During CRT, the patients were scheduled to receive gemcitabine/nab-paclitaxel at 7 dose levels using a standard 3 + 3 dose escalation scheme. Radiation therapy was concurrently delivered at a total dose of 60 Gy.

Results

Thirty-eight patients initiated induction gemcitabine/nab-paclitaxel. Among these patients, 30 received subsequent gemcitabine/nab-paclitaxel–based CRT. The RD was determined to be level 5 (gemcitabine, 800 mg/m2; nab-paclitaxel, 100 mg/m2). The dose-limiting toxicities included hematologic toxicity, infection, febrile neutropenia, and peripheral neuropathy. Twenty-four of 30 patients underwent pancreatectomy, and the R0 resection rate was 96%.

Conclusions

The RD of gemcitabine/nab-paclitaxel–based CRT after induction gemcitabine/nab-paclitaxel for patients with BRPC was 800 and 100 mg/m2, respectively.
Pancreatitis-Associated Genes and Pancreatic Cancer Risk
Authors: Cazacu Irina Mihaela , Farkas Nelli , Garami András , Balaskó Márta , Mosdósi Bernadett , Alizadeh Hussain , Gyöngyi Zoltán , Rakonczay Zoltán , Vigh Éva , Habon Tamás , Czopf László , Lazarescu Marilena Alina , Erőss Bálint , Sahin-Tóth Miklós , Hegyi Péter
Published: August 2018

Objective

The aim of this study was to evaluate the connection between pancreatic cancer (PC) and genetic variants associated with chronic pancreatitis via systematic review and meta-analysis.

Methods

The data search was performed in 3 major databases (PubMed, Embase, and Cochrane Library). The selected studies have looked into the presence of the pancreatitis-associated genes in patients with PC and in control subjects, the outcome being the frequency of the mutations in the 2 groups. For the binary outcomes, pooled odds ratio (OR) and 95% confidence interval (CI) were calculated.

Results

Ten articles proved to be eligible for the qualitative synthesis, and 8 articles were suitable for statistical analysis. Six case-control studies, comprising 929 PC cases and 1890 control subjects for serine protease inhibitor Kazal type 1 (SPINK1) mutations, and 5 case-control studies, comprising 1674 PC cases and 19,036 control subjects forCFTRmutations, were enrolled in our analysis.SPINK1mutations showed no association with PC (OR, 1.52; 95% CI, 0.67–3.45;P= 0.315), whereas mutations inCFTRmodestly increased the risk of PC (OR, 1.41; 95% CI, 1.07–1.84;P= 0.013).

Conclusion

Our meta-analysis showed that mutations inCFTRmodestly increase the risk of PC, whereas no association was found betweenSPINK1and PC.
Accurate Therapeutic Response Assessment of Pancreatic Ductal Adenocarcinoma Using Quantitative Dynamic Contrast-Enhanced Magnetic Resonance Imaging With a Point-of-Care Perfusion Phantom
Authors: Kim Harrison , Morgan Desiree E. , Schexnailder Patrick , Navari Rudolph M. , Williams Grant R. , Bart Rose J. , Li Yufeng , Paluri Ravikumar
Published: August 2018

Objectives

The aim of this study was to test the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with concurrent perfusion phantom for monitoring therapeutic response in patients with pancreatic ductal adenocarcinoma (PDAC).

Materials and Methods

A prospective pilot study was conducted with 8 patients (7 men and 1 woman) aged 46 to 78 years (mean age, 66 years). Participants had either locally advanced (n = 7) or metastatic (n = 1) PDAC, and had 2 DCE-MRI examinations: one before and one 8 ± 1 weeks after starting first-line chemotherapy. A small triplicate perfusion phantom was imaged with each patient, serving as an internal reference for accurate quantitative image analysis. Tumor perfusion was measured with Ktrans using extended Tofts model before and after phantom-based data correction. Results are presented as mean ± SD and 95% confidence intervals (CIs). Statistical difference was evaluated with 1-way analysis of variance.

Results

Tumor-size change of responding group (n = 4) was −12% ± 4% at 8 weeks of therapy, while that of nonresponding group (n = 4) was 18% ± 15% (P = 0.0100). Before phantom-based data correction, the Ktrans change of responding tumors was 69% ± 23% (95% CI, 32% to 106%) at 8 weeks, whereas that of nonresponding tumors was −1% ± 41% (95% CI, −65% to 64%) (P = 0.0247). After correction, the data variation in each group was significantly reduced; the Ktrans change of responding tumors was 73% ± 6% (95% CI, 64% to 82%) compared with nonresponding tumors of −0% ± 5% (95% CI, −7% to 8%) (P < 0.0001).

Conclusions

Quantitative DCE-MRI measured the significant perfusion increase of PDAC tumors responding favorably to chemotherapy, with decreased variability after correction using a perfusion phantom.
Impact of a Novel Preoperative Patient-centered Surgical Wellness Program
Authors: Kelley Kristen E. , Fajardo Alyssa D. , Strange Nancy M. , Harmon Carol A. , Pawlecki Kim , Sieber Marnie , Walke Nikki , Fadel William F. , Wooden William A. , Sadowski Josh , Birdas Thomas J. , Stevens Larry H. , Rozycki Grace S. , Schmidt C. Max
Published: August 2018

Objective:

The objective of this study was to evaluate if a preoperative wellness bundle significantly decreases the risk of hospital acquired infections (HAI).

Background:

HAI threaten patient outcomes and are a significant burden to the healthcare system. Preoperative wellness efforts may significantly decrease the risk of infections.

Methods:

A group of 12,396 surgical patients received a wellness bundle in a roller bag during preoperative screening at an urban academic medical center. The wellness bundle consisted of a chlorhexidine bath solution, immuno-nutrition supplements, incentive spirometer, topical mupirocin for the nostrils, and smoking cessation information. Study staff performed structured patient interviews, observations, and standardized surveys at key intervals throughout the perioperative period. Statistics compare HAI outcomes of patients in the wellness program to a nonintervention group using the Fisher's exact test, logistic regression, and Poisson regression.

Results:

Patients in the nonintervention and intervention groups were similar in demographics, comorbidity, and type of operations. Compliance with each element was high (80% mupirocin, 72% immuno-nutrition, 71% chlorhexidine bath, 67% spirometer). The intervention group had statistically significant reductions in surgical site infections, Clostridium difficile, catheter associated urinary tract infections, and patient safety indicator 90.

Conclusions:

A novel, preoperative, patient-centered wellness program dramatically reduced HAI in surgical patients at an urban academic medical center.
A rapid change in P-element-induced hybrid dysgenesis status in Ukrainian populations ofDrosophila melanogaster
Authors: Kozeretska I. A. , Shulha V. I. , Serga S. V. , Rozhok A. I. , Protsenko O. V. , Lau N. C.
Published: August 2018

TheDrosophila melanogasterP-transposable element is an example of mobile DNA transferred horizontally and known to have spread globally over the last 50–60 years. InDrosophila, the P-element causes a syndrome known as ‘P–M hybrid dysgenesis' that obstructs normal ovary development in the female progeny of susceptible populations. Despite extensive research, the stability and global population dynamics of P–M dysgenic phenotypes remain poorly understood. Here, we report a recent and rapid transition in the P–M status ofD. melanogasterpopulations from Ukraine. We demonstrate that these populations are currently dominated by the P′-cytotype characterized by active genomic P-elements and unknown from Ukraine just two decades ago. Our results suggest a recent invasion of the P-element in Ukraine, a pattern that matches recent discoveries from Turkey.
Sperm morph and remating frequency in the Indian meal moth,
Plodia interpunctella
Authors: Thorburn Doko-Miles J. , Knell Robert J. , Parrett Jonathan M.
Published: August 2018

All Lepidoptera produce two sperm types: normal, nucleated ‘eupyrene’ sperm and anucleate ‘apyrene’ sperm. One hypothesis for the evolution of apyrene sperm suggests that they act to reduce female remating rate. Apyrene sperm require less resources to produce than do eupyrene sperm, and could delay remating by females by acting as a ‘cheap filler’, packing the spermatheca and thereby reducing receptivity. This would reduce the risk of sperm competition, giving a potential adaptive advantage to the male producing these sperm. This leads to the prediction that the probability of a female remating should correlate with the number of stored apyrene sperm, which has previously been supported by experiments using the green-veined white butterfly,
Pieris napi
. We repeated this experiment using the Indian meal moth,
Plodia interpunctella
. We find that in this species, eupyrene, not apyrene sperm number is the best predictor of female remating probability, indicating that the ‘cheap filler’ hypothesis for the function of apyrene sperm is not well supported in
Pl. interpunctella
.
The ‘filtering’ metaphor revisited: competition and environment jointly structure invasibility and coexistence
Authors: Germain Rachel M. , Mayfield Margaret M. , Gilbert Benjamin
Published: August 2018

‘Filtering’, or the reduction in species diversity that occurs because not all species can persist in all locations, is thought to unfold hierarchically, controlled by the environment at large scales and competition at small scales. However, the ecological effects of competition and the environment are not independent, and observational approaches preclude investigation into their interplay. We use a demographic approach with 30 plant species to experimentally test: (i) the effect of competition on species persistence in two soil moisture environments, and (ii) the effect of environmental conditions on mechanisms underlying competitive coexistence. We find that competitors cause differential species persistence across environments even when effects are lacking in the absence of competition, and that the traits which determine persistence depend on the competitive environment. If our study had been observational and trait-based, we would have erroneously concluded that the environment filters species with low biomass, shallow roots and small seeds. Changing environmental conditions generated idiosyncratic effects on coexistence outcomes, increasing competitive exclusion of some species while promoting coexistence of others. Our results highlight the importance of considering environmental filtering in the light of, rather than in isolation from, competition, and challenge community assembly models and approaches to projecting future species distributions.
Dynamic modelling of personal protection control strategies for vector-borne disease limits the role of diversity amplification
Authors: Demers Jeffery , Bewick Sharon , Calabrese Justin , Fagan William F.
Published: August 2018

Personal protection measures, such as bed nets and repellents, are important tools for the suppression of vector-borne diseases like malaria and Zika, and the ability of health agencies to distribute protection and encourage its use plays an important role in the efficacy of community-wide disease management strategies. Recent modelling studies have shown that a counterintuitive diversity-driven amplification in community-wide disease levels can result from a population's partial adoption of personal protection measures, potentially to the detriment of disease management efforts. This finding, however, may overestimate the negative impact of partial personal protection as a result of implicit restrictive model assumptions regarding host compliance, access to and longevity of protection measures. We establish a new modelling methodology for incorporating community-wide personal protection distribution programmes in vector-borne disease systems which flexibly accounts for compliance, access, longevity and control strategies by way of a flow between protected and unprotected populations. Our methodology yields large reductions in the severity and occurrence of amplification effects as compared to existing models.
In silico
mouse study identifies tumour growth kinetics as biomarkers for the outcome of anti-angiogenic treatment
Authors: Wu Qianhui , Arnheim Alyssa D. , Finley Stacey D.
Published: August 2018

Angiogenesis is a crucial step in tumour progression, as this process allows tumours to recruit new blood vessels and obtain oxygen and nutrients to sustain growth. Therefore, inhibiting angiogenesis remains a viable strategy for cancer therapy. However, anti-angiogenic therapy has not proved to be effective in reducing tumour growth across a wide range of tumours, and no reliable predictive biomarkers have been found to determine the efficacy of anti-angiogenic treatment. Using our previously established computational model of tumour-bearing mice, we sought to determine whether tumour growth kinetic parameters could be used to predict the outcome of anti-angiogenic treatment. A model trained with datasets from six
in vivo
mice studies was used to generate a randomized
in silico
tumour-bearing mouse population. We analysed tumour growth in untreated mice (control) and mice treated with an anti-angiogenic agent and determined the Kaplan–Meier survival estimates based on simulated tumour volume data. We found that the ratio between two kinetic parameters,
k
0
and
k
1
, which characterize the tumour's exponential and linear growth rates, as well as
k
1
alone, can be used as prognostic biomarkers of the population survival outcome. Our work demonstrates a robust, quantitative approach for identifying tumour growth kinetic parameters as prognostic biomarkers and serves as a template that can be used to identify other biomarkers for anti-angiogenic treatment.
Eco-evolutionary dynamics of a population with randomly switching carrying capacity
Authors: Wienand Karl , Frey Erwin , Mobilia Mauro
Published: August 2018

Environmental variability greatly influences the eco-evolutionary dynamics of a population, i.e. it affects how its size and composition evolve. Here, we study a well-mixed population of finite and fluctuating size whose growth is limited by a randomly switching carrying capacity. This models the environmental fluctuations between states of resources abundance and scarcity. The population consists of two strains, one growing slightly faster than the other, competing under two scenarios: one in which competition is solely for resources, and one in which the slow (cooperating) strain produces a public good (PG) that benefits also the fast (free-riding) strain. We investigate how the coupling of demographic and environmental (external) noise affects the population's eco-evolutionary dynamics. By analytical and computational means, we study the correlations between the population size and its composition, and discuss the social-dilemma-like ‘eco-evolutionary game’ characterizing the PG production. We determine in what conditions it is best to produce a PG; when cooperating is beneficial but outcompeted by free riding, and when the PG production is detrimental for cooperators. Within a linear noise approximation to populations of varying size, we also accurately analyse the coupled effects of demographic and environmental noise on the size distribution.
An experimental study of deformation and fracture characteristics of shale with pore-water pressure and under triaxial cyclic loading
Authors: Jiang Changbao , Lu Tianyu , Zhang Dongming , Li Guangzhi , Duan Minke , Chen Yufei , Liu Chaosheng
Published: August 2018

The deformation and fracture characteristics of shale in the Changning-Xingwen region were experimentally studied under triaxial cyclic loading with a controlled pore-water pressure. An RLW-2000M microcomputer-controlled coal-rock rheometer was used in the State key Laboratory of coal mine disaster dynamics and control in Chongqing University. These experimental results have indicated the following. (i) The shale softened after being saturated with water, while its failure strength decreased with the increase of axial strain. (ii) A complete cyclic loading–unloading process can be divided into four stages under the coupling action of axial cyclic loading and pore-water pressure; namely the slow or accelerated increasing of strain in the loading stage, and the slow or accelerated decreasing of strain in the unloading stage. (iii) The axial plastic deformation characteristics were similar when pore-water pressures were set to 2, 6 and 10 MPa. Nevertheless, the shale softened ostensibly and fatigue damage occurred during the circulation process when the pore-water pressure was set to 14 MPa. (iv) It has been observed that the mean strain and strain amplitude under axial cyclic are positively correlated with pore-water pressure, while the elastic modulus is negatively correlated with pore-water pressure. As the cycle progresses, the trends in these parameters vary, which indicates that the deformation and elastic characteristics of shale are controlled by pore-water pressure and cyclic loading conditions. (v) Evidenced via triaxial compression tests, it was predominantly shear failure that occurred in the shale specimens. In addition, axial cyclic loading caused the shale to generate complex secondary fractures, resulting in the specimens cracking along the bedding plane due to the effect of pore-water pressure. This study provides valuable insight into the understanding of the deformation and failure mechanisms of shale under complicated stress conditions.
Disruption of skin microbiota contributes to salamander disease
Authors: Bletz Molly C. , Kelly Moira , Sabino-Pinto Joana , Bales Emma , Van Praet Sarah , Bert Wim , Boyen Filip , Vences Miguel , Steinfartz Sebastian , Pasmans Frank , Martel An
Published: August 2018

Escalating occurrences of emerging infectious diseases underscore the importance of understanding microbiome–pathogen interactions. The amphibian cutaneous microbiome is widely studied for its potential to mitigate disease-mediated amphibian declines. Other microbial interactions in this system, however, have been largely neglected in the context of disease outbreaks. European fire salamanders have suffered dramatic population crashes as a result of the newly emerged
Batrachochytrium salamandrivorans
(
Bsal
). In this paper, we investigate microbial interactions on multiple fronts within this system. We show that wild, healthy fire salamanders maintain complex skin microbiotas containing
Bsal
-inhibitory members, but these community are present at a remarkably low abundance. Through experimentation, we show that increasing bacterial densities of
Bsal
-inhibiting bacteria via daily addition slowed disease progression in fire salamanders. Additionally, we find that experimental-
Bsal
infection elicited subtle changes in the skin microbiome, with selected opportunistic bacteria increasing in relative abundance resulting in septicemic events that coincide with extensive destruction of the epidermis. These results suggest that fire salamander skin, in natural settings, maintains bacterial communities at numbers too low to confer sufficient protection against
Bsal,
and, in fact, the native skin microbiota can constitute a source of opportunistic bacterial pathogens that contribute to pathogenesis. By shedding light on the complex interaction between the microbiome and a lethal pathogen, these data put the interplay between skin microbiomes and a wildlife disease into a new perspective.
Australian native mammals recognize and respond to alien predators: a meta-analysis
Authors: Banks Peter B. , Carthey Alexandra J. R. , Bytheway Jenna P.
Published: August 2018

Prey naiveté is a failure to recognize novel predators and thought to cause exaggerated impacts of alien predators on native wildlife. Yet there is equivocal evidence in the literature for native prey naiveté towards aliens. To address this, we conducted a meta-analysis of Australian mammal responses to native and alien predators. Australia has the world's worst record of extinction and declines of native mammals, largely owing to two alien predators introduced more than 150 years ago: the feral cat,Felis catus, and European red fox,Vulpes vulpes. Analysis of 94 responses to predator cues shows that Australian mammals consistently recognize alien foxes as a predation threat, possibly because of thousands of years of experience with another canid predator, the dingo,Canis lupus dingo. We also found recognition responses towards cats; however, in four of the seven studies available, these responses were of risk-taking behaviour rather than antipredator behaviour. Our results suggest that a simple failure to recognize alien predators is not behind the ongoing exaggerated impacts of alien predators in Australia. Instead, our results highlight an urgent need to better understand the appropriateness of antipredator responses in prey towards alien predators in order to understand native prey vulnerability.
Combined exposure to sublethal concentrations of an insecticide and a fungicide affect feeding, ovary development and longevity in a solitary bee
Authors: Sgolastra Fabio , Arnan Xavier , Cabbri Riccardo , Isani Gloria , Medrzycki Piotr , Teper Dariusz , Bosch Jordi
Published: August 2018

Pollinators in agroecosystems are often exposed to pesticide mixtures. Even at low concentrations, the effects of these mixtures on bee populations are difficult to predict due to potential synergistic interactions. In this paper, we orally exposed newly emerged females of the solitary bee
Osmia bicornis
to environmentally realistic levels of clothianidin (neonicotinoid insecticide) and propiconazole (fungicide), singly and in combination. The amount of feeding solution consumed was highest in bees exposed to the neonicotinoid, and lowest in bees exposed to the pesticide mixture. Ovary maturation and longevity of bees of the neonicotinoid and the fungicide treatments did not differ from those of control bees. By contrast, bees exposed to the pesticide mixture showed slow ovary maturation and decreased longevity. We found a synergistic interaction between the neonicotinoid and the fungicide on survival probability. We also found an interaction between treatment and emergence time (an indicator of physiological condition) on longevity. Longevity was negatively correlated to physiological condition only in the fungicide and the mixture treatments. Delayed ovary maturation and premature death imply a shortened nesting period (highly correlated to fecundity in
Osmia
). Our findings provide a mechanism to explain the observed dynamics of solitary bee populations exposed to multiple chemical residues in agricultural environments.
Multiple biological mechanisms result in correlations between pre- and post-mating traits that differ among versus within individuals and genotypes
Authors: Tuni Cristina , Han Chang S. , Dingemanse Niels J.
Published: August 2018

Reproductive traits involved in mate acquisition (pre-mating traits) are predicted to covary with those involved in fertilization success (post-mating traits). Variation in male quality may give rise to positive, and resource allocation trade-offs to negative, covariances between pre- and post-mating traits. Empirical studies have yielded mixed results. Progress is hampered as researchers often fail to appreciate that mentioned biological mechanisms can act simultaneously but at different hierarchical levels of biological variation: genetic correlations may, for example, be negative due to genetic trade-offs but environmental correlations may instead be positive due to individual variation in resource acquisition. We measured pre-mating (aggression, body weight) and post-mating (ejaculate size) reproductive traits in a pedigreed population of southern field crickets (Gryllus bimaculatus). To create environmental variation, crickets were raised on either a low or a high nymphal density treatment. We estimated genetic and environmental sources of correlations between pre- and post-mating traits. We found positive genetic correlations between pre- and post-mating traits, implying the existence of genetic variation in male quality. Over repeated trials of the same individual (testing order), positive changes in one trait were matched with negative changes in other traits, suggesting energy allocating trade-offs within individuals among days. These findings demonstrate the need for research on pre- and post-mating traits to consider the hierarchical structure of trait correlations. Only by doing so was our study able to conclude that multiple mechanisms jointly shape phenotypic associations between pre- and post-mating traits in crickets.
Mesoscale activity facilitates energy gain in a top predator
Authors: Abrahms Briana , Scales Kylie L. , Hazen Elliott L. , Bograd Steven J. , Schick Robert S. , Robinson Patrick W. , Costa Daniel P.
Published: August 2018

How animal movement decisions interact with the distribution of resources to shape individual performance is a key question in ecology. However, links between spatial and behavioural ecology and fitness consequences are poorly understood because the outcomes of individual resource selection decisions, such as energy intake, are rarely measured. In the open ocean, mesoscale features (approx. 10–100 km) such as fronts and eddies can aggregate prey and thereby drive the distribution of foraging vertebrates through bottom-up biophysical coupling. These productive features are known to attract predators, yet their role in facilitating energy transfer to top-level consumers is opaque. We investigated the use of mesoscale features by migrating northern elephant seals and quantified the corresponding energetic gains from the seals' foraging patterns at a daily resolution. Migrating elephant seals modified their diving behaviour and selected for mesoscale features when foraging. Daily energy gain increased significantly with increasing mesoscale activity, indicating that the physical environment can influence predator fitness at fine temporal scales. Results show that areas of high mesoscale activity not only attract top predators as foraging hotspots, but also lead to increased energy transfer across trophic levels. Our study provides evidence that the physical environment is an important factor in controlling energy flow to top predators by setting the stage for variation in resource availability. Such understanding is critical for assessing how changes in the environment and resource distribution will affect individual fitness and food web dynamics.
Trait-dependent tolerance of bats to urbanization: a global meta-analysis
Authors: Jung Kirsten , Threlfall Caragh Grace
Published: August 2018

Urbanization is a severe threat to global biodiversity, often leading to taxonomic and functional homogenization. However, current urban ecology research has focused mostly on urban birds and plants, limiting our ability to make generalizations about the drivers of urban biodiversity globally. To address this gap, we conducted a global meta-analysis of 87 studies, including 180 bat species (Chiroptera) from urban areas in Asia, Australia, Europe, North and South America. We aimed to (i) understand the importance of functional traits and phylogeny in driving changes in urban bat assemblages, and (ii) assess the capacity of traits for predicting which types of species are most sensitive to urbanization. Our results indicate that species-specific functional traits explain differences in the intensity of urban habitat use. Urban tolerance mainly occurred within the open and edge space foraging and trawling species as well as in bats with flexible roosting strategies. In addition, across bioregions and independent of phylogeny, urban tolerance correlated with higher aspect ratio, a trait enabling fast flight but less agile manoeuvres during aerial food acquisition. Predictive success varied between bioregions, between 43 and 83%. Our analysis demonstrates that the local extinction of bat species in urban areas is non-random, trait-based and predictable, allowing urban landscape managers to tailor local conservation actions to particular types of species.