bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoluminescence and piezoelectric behaviour of Y2Zr2O7 pyrochlore‐based multifunctional materials and the influence of Eu3+ and Sm3+
Authors: Öztürk Esra , Karacaoglu Erkul , Kalem Volkan
Published: January 2020

Y2Zr2O7‐doped with Eu3+ and Sm3+ phosphors were prepared for the first time as multifunctional smart materials using a solid‐state reaction method at 1400oC. Thermal behaviour, crystal structure, surface morphology, and elemental analysis were characterized using thermogravimetric (TG) and differential thermal (DTA) analyses, X‐ray diffraction (XRD) and scanning electron microscope equipped with energy‐dispersive X‐ray spectroscopy (SEM‐EDX). Experimental results revealed that both phosphors have a pyrochlore structure with a cubic crystal system. Photoluminescence properties were also measured and red emission was observed from Y1.90Eu0.10Zr2O7 and Y1.90Sm0.10Zr2O7 phosphors. Dielectric constant, loss tangent, piezoelectric charge constant, and Curie temperature of all the samples were determined using an LCR‐meter, d33‐meter, and TG/DTA. Eu doping in Y2Zr2O7 resulted in a high dielectric constant (9.61) and low loss tangent (1.67%) values, whereas high piezoelectric charge constant (0.68 pC/N) and high Curie temperature (820°C) could be obtained using Sm‐doped Y2Zr2O7.
Scoping review of mode of anaesthesia in emergency surgery
Authors: Morley R L , Elliott L , Rees J , Rudd S , Mouton R , Hinchliffe R J
Published: January 2020

Background

Emergency surgery encompasses more than 50 per cent of the surgical workload; however, research efforts are disproportionally low. The mode of anaesthesia used during emergency surgery may affect outcomes, but the extent of research and the impact of the different modes of anaesthesia used are unclear.

Methods

MEDLINE and Embase were searched using scoping review methodology with a rapid systematic search strategy, identifying any study comparing locoregional (local, nerve block, subarachnoid, epidural) anaesthesia with general anaesthesia. All studies describing outcomes of emergency surgery with differing modes of anaesthesia were identified. Excluded were: studies published before 2003, studies enrolling patients aged less than 18 years and studies using sedation only.

Results

Forty-two studies were identified, describing 11 surgical procedures. Most publications were retrospective cohort studies (32). A very broad range of clinical and patient-reported outcomes were described, with wide variation in the outcomes reported in different studies.

Conclusion

Reporting of mode of anaesthesia is inconsistent across different procedures and is often absent. There is a need for directed research efforts to improve the reporting standards of anaesthesia interventions, to understand the role of different modes of anaesthesia in specific emergency surgical procedures, and to standardize outcome reporting using core outcome sets.
The interplay between stakeholders, resources and capabilities in climate change strategy: converting barriers into cooperation
Authors: Lopes de Sousa Jabbour Ana Beatriz , Vazquez‐Brust Diego , Chiappetta Jabbour Charbel José , Andriani Ribeiro Daniela
Published: January 2020

This article investigates how organizations deal with drivers and barriers to the adoption of low‐carbon operational (LCO) practices and, accordingly, we propose a framework for relationships with stakeholders to guide organizations in orchestrating stakeholders, resources and capabilities to meet the challenges and opportunities arising from climate change. Data was collected through interviews with experts working within companies participating in the Carbon Disclosure Program and the Brazilian GHG Protocol Program. Our findings show that the level of willingness of stakeholders influences how companies select mechanisms to deal with drivers and barriers to LCO practices. Our results, qualified by stakeholder relationships theory and the natural resource‐based view, introduce an analytical approach called ‘mechanisms of responses’ to understand how organizations deal with drivers and barriers in the context of climate change in order to guide companies to adopt LCO practices, strengthen co‐operation with stakeholders and develop the required organizational capabilities.
Transient increase of microglial C1q expression in the circumventricular organs of adult mouse during LPS‐induced inflammation
Authors: Kawai Shintaro , Kurganov Erkin , Miyata Seiji
Published: January 2020

The circumventricular organs (CVOs) are the brain regions that lack the blood‐brain barrier and allow free entry of blood‐derived molecules, offering specialized niche to initiate rapid and early neuroinflammatory responses in the brain. Complement component 1q (C1q) is shown to be the first recognition component of the complement pathway and has a crucial function in the brain under pathological conditions. In the present study, we found that C1q expression in CX3CR1‐positive microglia was increased in the CVOs and their neighbouring brain regions of adult mice at 1 day after a single administration of 1 mg/kg lipopolysaccharide (LPS), whereas it returned to control levels at 3 days after LPS stimulation. C1q expression was also seen to localize at synapsin‐positive presynaptic axonal terminals in various brain regions. Thus, the present study demonstrates a transient upregulation of microglial C1q expression in the CVOs and their adjacent brain regions, indicating that a transient upregulation of C1q is possibly concerned with physiological responses at early phase of brain inflammation.

Significance of the Study

The circumventricular organs (CVOs) are specialized brain regions that lack the blood‐brain barrier (BBB) and initiate neuroinflammatory responses in the brains. The present study showed that the expression of complement protein C1q was highly increased in microglia of the CVOs and their adjacent brain regions. Moreover, C1q expression was observed to localize specifically at presynaptic axonal terminals in the CVOs and their neighbouring brain regions. Thus, the present study indicates that C1q is possibly correlated with physiological responses at early phase of brain inflammation.
Development and validation of a predictive score for anterograde crossing of infrapopliteal chronic total occlusions: (The Infrapop‐CTO Score)
Authors: Kokkinidis Damianos G. , Strobel Aaron , Jawaid Omar , Haider Moosa N. , Alvandi Bejan , Singh Gagan D. , Laird John R. , Waldo Stephen W. , Armstrong Ehrin J.
Published: January 2020

Background

Patients with critical limb ischemia often have infrapopliteal (IP) chronic total occlusions (CTOs). While revascularization is indicated to prevent major amputation, anterograde crossing of these lesions can be challenging, with high failure rates.

Objective

To develop and validate a scoring system that can adequately predict successful anterograde crossing of infrapopliteal CTOs.

Methods and Results

A total of 213 IP CTOs (147 successfully crossed with the anterograde approach vs. 66 where anterograde crossing failed) were included in the analysis. Backwards stepwise selection (p for retention <.05) was used to create a multivariable logistic regression model for the prediction of successful anterograde crossing using variables that were found to have a p < .1 in univariate analysis. The model was internally validated with bootstrapping and demonstrated excellent discriminatory ability (C‐statistic 0.78 and Hosmer‐Lemeshow p value = .61). A point score based on the beta‐coefficient of the model variables was created, with one point assigned for presence of a noncentral (blunt) stump, one point for severe calcification at the entry site, and two points each for non‐restenotic lesions or lesion length > 200 mm. The score was shown to have an excellent discriminatory ability for successful crossing, with low scores (0–2) associated with low failure rates (10%) and high scores associated with high failure rates (79%).

Conclusions

The Infrapop‐CTO score can stratify the procedural complexity of IP CTOs based on the likelihood of successful anterograde crossing. This score may help to direct optimal approaches toward infrapopliteal revascularization of patients with critical limb ischemia.
Functional measurement error in functional regression
Authors: Jadhav Sneha , Ma Shuangge
Published: January 2020

Abstract

Measurement error is an important problem that has not been studied very well in the context of functional data analysis. To the best of our knowledge, there are no existing methods that address the presence of functional measurement errors in generalized functional linear models. In this article, a novel approach is proposed to estimate the slope function in the presence of measurement error in the generalized functional linear model with a scalar response. This work significantly advances the existing conditional score method to accommodate the case where both the measurement error and independent variables lie in infinite dimensional spaces. Asymptotic results are established for the proposed estimate, and its behaviour is studied via simulations, where the response is continuous or binary. Analysis of Canadian Weather data highlights the practical utility of our method. The Canadian Journal of Statistics 48: 238–258; 2020 © 2020 Statistical Society of Canada
Genomic and clinical characterization of stromal infiltration markers in prostate cancer
Authors: Mahal Brandon A. , Alshalalfa Mohammed , Zhao Shuang G. , Beltran Himisha , Chen William S. , Chipidza Fallon , Davicioni Elai , Karnes R. Jeffrey , Ku Sheng‐Yu , Lotan Tamara L. , Muralidhar Vinayak , Rebbeck Timothy R. , Schaeffer Edward M. , Spratt Daniel E. , Feng Felix Y. , Nguyen Paul L.
Published: January 2020

Background

The progression of prostate cancer is a complex, multistep process that involves molecular alterations in cells of the tumor and the microenvironment, with associated interactions between the stroma and epithelium. Genomic expression analyses of stromal infiltration markers were performed to determine the significance thereof in prostate cancer.

Methods

Genome‐wide expression profiles of formalin‐fixed, paraffin‐embedded radical prostatectomy samples were evaluated from a prospective registry cohort (n = 5239) and 3 retrospective institutional cohorts (n = 1135). Two independent stromal gene expression signatures implied stromal infiltration. Cox proportional hazards regression defined the association between stromal infiltration expression and metastasis‐free survival (MFS).

Results

Stromal expression scores were correlated with stromal signature genes and with other key stromal markers (CAV1, VIM, and TAGLN), basal activity, and CD3 and CD4 immune biomarkers (r > 0.5 for all). The top decile of stromal expression was associated with high genomic risk scores (Decipher ≥ 0.6) , high Cancer of the Prostate Risk Assessment–Postsurgical scores, Gleason 9 to 10 disease, and a higher risk for metastasis (hazard ratio, 2.35; 95% CI, 1.37‐4.02; P = .001). A higher stromal infiltration score was also associated with decreased expression of DNA repair genes and higher radiation sensitivity genomic scores. Postoperative radiation therapy (RT) was associated with an MFS benefit for patients with high stromal scores, but not for patients with low stromal scores (Pinteraction = .02).

Conclusions

Expression of stromal infiltration markers is correlated with prostate cancer aggressiveness/progression and may be predictive of a response to RT. Stromal infiltration markers should be studied and considered for incorporation into clinical prognostication and decision making.
Machine learning approaches to study glioblastoma: A review of the last decade of applications
Authors: Valdebenito Jessica , Medina Felipe
Published: January 2020

Background

Glioblastoma (GB, formally glioblastoma multiforme) is a malignant type of brain cancer that currently has no cure and is characterized by being highly heterogeneous with high rates of re‐incidence and therapy resistance. Thus, it is urgent to characterize the mechanisms of GB pathogenesis to help researchers identify novel therapeutic targets to cure this devastating disease. Recently, a promising approach to identifying novel therapeutic targets is the integration of tumor omics data with clinical information using machine learning (ML) techniques.

Recent findings

ML has become a valuable addition to the researcher's toolbox, thanks to its flexibility, multidimensional approach, and a growing community of users. The goal of this review is to introduce basic concepts and applications of ML for studying GB to clinicians and practitioners who are new to data science. ML applications include exploring large data sets, finding new relevant patterns, predicting outcomes, or merely understanding associations of the complex molecular networks presented within the tumor. Here, we review ML applications published between 2008 and 2018 and discuss ML strategies intending to identify new potential therapeutic targets to improve the management and treatment of GB.

Conclusions

ML applications to study GB vary in purpose and complexity, with positive results. In GB studies, ML is often used to analyze high‐dimensional datasets with prediction or classification as a primary goal. Despite the strengths of ML techniques, they are not fail‐safe and methodological issues can occur in GB studies that use them. This is why researchers need to be aware of these issues when planning and appraising studies that apply ML to the study of GB.
The optimal number of sensors for a digital imaging system from the perspective of metamer mismatching
Authors: Zhang Xiandou , Wang Mengmeng , Wei Minchen , Wang Yong , Liu Shuo
Published: January 2020

Metamer mismatching occurs in both the human visual system and digital imaging systems. Increasing the number of sensors in digital imaging systems is an efficient method to reduce the degree of metamer mismatching. This study investigates the number of sensors that are needed for the digital imaging systems to have a similar ability to the human sensor system in distinguishing colors from the perspective of metamer mismatching. Optimal spectral reflectance was generated, and a dataset with more than 47 million previously collected practical spectral reflectance functions was used to derive the metameric color pairs. Different sets of Gaussian‐shaped functions were designed to model the spectral sensitivity functions of the digital imaging systems. Both the metamer mismatching volumes and color differences were used to characterize the degree of metamer mismatching for pairs of samples, which were metameric to the imaging systems but appeared different to the human sensor system. The results show that the practical metamer mismatching volumes are substantially smaller than the theoretical ones. The results also show that both the metamer mismatching volumes and color differences are significantly reduced by increasing the number of sensors from three to five for the digital imaging system but are only slightly reduced by further increasing the number of sensors from five to seven. This indicates that five sensors is an efficient and optimal solution for an imaging system with Gaussian‐shaped sensors to have a similar ability in distinguishing colors compared to the human sensor system.
How does domestic violence influence the likelihood of settlement in mediation? New data answers old questions
Authors: Raines Susan S. , Indovina Vittorio
Published: January 2020

This study seeks empirical evidence to answer critical questions surrounding domestic violence (DV) and mediation: Are survivors of DV being coerced into reaching unfair and unsafe agreements? Do all DV behaviors have the same impact on settlement? Does stalking predict impasse less than a history of physical violence? Do survivors feel safe in mediation compared to adjudication or attorney‐negotiated settlement? This study answers these critical questions in order to understand which cases are likely to benefit from mediation. This research empowers screeners, mediators, court employees and attorneys to better discern which cases are most likely to benefit from mediation.
Human body odor increases familiarity for faces during encoding‐retrieval task
Authors: Cecchetto Cinzia , Fischmeister Florian Ph. S. , Gorkiewicz Sarah , Schuehly Wolfgang , Bagga Deepika , Parma Valentina , Schöpf Veronika
Published: January 2020

Odors can increase memory performance when presented as context during both encoding and retrieval phases. Since information from different sensory modalities is integrated into a unified conceptual knowledge, we hypothesize that the social information from body odors and faces would be integrated during encoding. The integration of such social information would enhance retrieval more so than when the encoding occurs in the context of common odors. To examine this hypothesis and to further explore the underlying neural correlates of this behavior, we have conducted a functional magnetic resonance imaging study in which participants performed an encoding‐retrieval memory task for faces during the presentation of common odor, body odor or clean air. At the behavioral level, results show that participants were less biased and faster in recognizing faces when presented in concomitance with the body odor compared to the common odor. At the neural level, the encoding of faces in the body odor condition, compared to common odor and clean air conditions, showed greater activation in areas related to associative memory (dorsolateral prefrontal cortex), odor perception and multisensory integration (orbitofrontal cortex). These results suggest that face and body odor information were integrated and as a result, participants were faster in recognizing previously presented material.
Prevalence of NUT carcinoma in head and neck: Analysis of 362 cases with literature review
Authors: Lee Taebum , Cho Junhun , Baek Chung‐Hwan , Son Young‐Ik , Jeong Han‐Sin , Chung Man Ki , Hong Sang Duk , Ahn Yong Chan , Oh Dong Ryul , Noh Jae Myoung , Park Keunchil , Ahn Myung‐Ju , Kim Hyung‐Jin , Kim Yi Kyung , Ko Young Hyeh
Published: January 2020

Background

Nuclear protein in testis (NUT) carcinoma is a poorly differentiated carcinoma defined by the presence of NUT gene rearrangement. In the head and neck, the true prevalence of NUT carcinoma is unknown.

Methods

We retrospectively investigated NUT expression with clinicopathologic features in 362 patients of poorly differentiated or undifferentiated carcinomas in the head and neck, and reviewed the literature reports.

Results

Four (4/362, 1.1%) cases showed strong nuclear expression for NUT‐specific monoclonal antibody, and all these tumors were in the sinonasal tract (4/40, 10%). The clinical outcome and histology were diverse unlike previously described. Although previous studies reported different frequency results according to study subjects, frequencies in sinonasal tract are relatively constant (10/80, 12.5%).

Conclusions

This is the largest study on the prevalence of NUT carcinoma in head and neck areas. It is important to include in the differential diagnosis of poorly differentiated carcinoma, particularly in the sinonasal tract.
Heterogeneous investment horizons, risk regimes, and realized jumps
Authors: Erdemlioglu Deniz , Gradojevic Nikola
Published: January 2020

This paper introduces a new empirical framework to identify the regimes of jump‐type tail risk over multiple trading horizons. Our approach combines the hidden Markov regime‐switching model with realized jumps, which allows us to examine the tail risk exposure of investors at different investment scales. Applying our method to data on bonds, stocks, and currencies, we find evidence that market risk linked to jumps exhibits time‐varying regime shifts and horizon‐dependence. We show that high‐frequency trading does not contribute to market instability, as measured by jump risk. The European bond market appears to be more vulnerable to downside (left‐tail) jump risk, relative to the U.S. Treasury bond market. Market jump fear embedded in the VIX exhibits vertical clustering where both risk regimes at low frequencies remain unchanged at higher frequencies. These results suggest that the premium for jump risk not only depends on stress periods, but also on the frequency at which investors trade financial assets.
Spring to summer nitrogen level in a brackish lake is higher in abundant snowmelt years: Correlation and causation
Authors: Shizuka Kazunori , Maie Nagamitsu , Nagasaki Masayasu , Kakino Wataru , Tanji Hajime
Published: January 2020

Eutrophication is an issue of concern in many brackish lakes with an agricultural watershed. The amount of snowfall in snowy areas is anticipated to decline because of global climate change. The aim of this study was to assess the impact of changes in the inflow of snowmelt on the nutrient concentrations of a downstream brackish lake. In Lake Ogawara, a brackish lake in a snow‐covered agricultural area of Japan, we examined the relationships between inflowing river discharge (D/C) during spring and total nitrogen (TN) and total phosphorus (TP) concentrations in the mixolimnion of the lake ([TNmix] and [TPmix], respectively) using 29 yr of monitoring data. In addition, we assessed the causal relationship between the D/C and the lake nutrient concentrations. There was large year‐to‐year variation in D/C during April (D/CApr), which accounted for 7–31% of the mixolimnion volume. Significant positive correlations were observed between D/CApr and [TNmix] from the ensuing April to September. On an annual basis, 49% of the interannual variation of the mean [TNmix] during the ensuing April to September was explained by the interannual variation of D/CApr. Therefore, D/CApr could be useful as a simple index to [TNmix] in the ensuing spring to summer. It is notable that the relationships between D/CApr and [TNmix] from April to September was indicated to be acausal by statistical causal inference. Common climate conditions that increase D/CApr (i.e., a cold winter with a high level of precipitation) were found to drive other biogeochemical processes that increased [TNmix] during the ensuing spring to summer.
Simplifying the clinical classification of polymerase gamma (POLG) disease based on age of onset; studies using a cohort of 155 cases
Authors: Hikmat Omar , Naess Karin , Engvall Martin , Klingenberg Claus , Rasmussen Magnhild , Tallaksen Chantal ME , Brodtkorb Eylert , Ostergaard Elsebet , de Coo I. F. M , Pias‐Peleteiro Leticia , Isohanni Pirjo , Uusimaa Johanna , Darin Niklas , Rahman Shamima , Bindoff Laurence A.
Published: January 2020

Background

Variants in POLG are one of the most common causes of inherited mitochondrial disease. Phenotypic classification of POLG disease has evolved haphazardly making it complicated and difficult to implement in everyday clinical practise. The aim of our study was to simplify the classification and facilitate better clinical recognition.

Methods

A multinational, retrospective study using data from 155 patients with POLG variants recruited from seven European countries.

Results

We describe the spectrum of clinical features associated with POLG variants in the largest known cohort of patients. While clinical features clearly form a continuum, stratifying patients simply according to age of onset—onset prior to age 12 years; onset between 12 and 40 years and onset after the age of 40 years, permitted us to identify clear phenotypic and prognostic differences. Prior to 12 years of age, liver involvement (87%), seizures (84%), and feeding difficulties (84%) were the major features. For those with onset between 12 and 40 years, ataxia (90%), peripheral neuropathy (84%), and seizures (71%) predominated, while for those with onset over 40 years, ptosis (95%), progressive external ophthalmoplegia (89%), and ataxia (58%) were the major clinical features. The earlier the onset the worse the prognosis. Patients with epilepsy and those with compound heterozygous variants carried significantly worse prognosis.

Conclusion

Based on our data, we propose a simplified POLG disease classification, which can be used to guide diagnostic investigations and predict disease course.
The Influence of Water Depth on Energy Availability for Ducks
Authors: Behney Adam C.
Published: January 2020

Habitat management and planning strategies for nonbreeding ducks are focused on providing enough energy to support a desired number of individuals. Therefore, regional estimates of energy availability for nonbreeding ducks are required to determine if sufficient habitat exists for them. I used core sampling to estimate food and energy density in 6 types of water bodies (i.e., actively and passively managed emergent wetlands, playas, small and large reservoirs, and sloughs) in northeastern Colorado, USA, during 3 sampling occasions throughout 2 nonbreeding seasons, 2015–2016 and 2016–2017. Also, I used precise depth measurements to estimate the percentage of each site that was shallow enough to facilitate feeding by dabbling ducks as a way to correct overall energy density to reflect availability to ducks. Emergent wetlands contained the greatest food and energy density, followed by playas and sloughs, and reservoirs contained little food or energy. Fall depletion of food was greatest in actively managed emergent wetlands and spring depletion was greatest in sloughs and passively managed emergent wetlands. Mean percentage of passively managed emergent wetlands, actively managed emergent wetlands, small reservoirs, large reservoirs, and sloughs shallower than 50 cm was 37%, 77%, 10%, 4%, and 83%, respectively. Incorporating these estimates into the energetic carrying capacity model developed by the Playa Lakes Joint Venture for eastern Colorado resulted in a 54% decrease in overall duck energy day estimates, which is below what is needed to support population goals. This research identifies the need for additional wetland restoration in eastern Colorado to meet energy requirements of nonbreeding ducks and provides information to conservation planners to make more informed decisions about the extent and location of wetland restoration activities. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.
Genetic Characteristics of Restored Elk Populations in Kentucky
Authors: Youngmann Jordan L. , Deyoung Randy W. , Demarais Stephen , Strickland Bronson K. , Jenkins Gabe
Published: January 2020

Translocations are a common management practice to restore or augment populations. Understanding the genetic consequences of translocation efforts is important for the long‐term health of restored populations. The restoration of elk (Cervus canadensis) to Kentucky, USA, included source stocks from 6 western states, which were released at 8 sites in southeastern Kentucky during 1997–2002. We assessed genetic diversity in restored herds and compared genetic similarity to source stocks based on 15 microsatellite DNA loci. Genetic variation in the restored populations was comparable to source stocks (allelic richness = 3.52 and 3.50;expected heterozygosity = 0.665 and 0.661 for restored and source, respectively). Genetic differentiation among all source and restored populations ranged from 0.000 to 0.065 for pairwise FSTand 0.034 to 0.161 for pairwise Nei's DA. Pairwise genetic differentiation and Bayesian clustering revealed that stocks from Utah and North Dakota, USA, contributed most to restored populations. Other western stocks appeared less successful and were not detected with our data, though our sampling was not exhaustive. We also inferred natural movements of elk among release sites by the presence of multiple genetic stocks. The success of the elk restoration effort in Kentucky may be due, in part, to the large number of elk (n = 1,548), repeated releases, and use of diverse source stocks. Future restoration efforts for elk in the eastern United States should consider the use of multiple stock sources and a large number of individuals. In addition, preservation of genetic samples of founder stock will enable detailed monitoring in the future. © 2020 The Authors. TheJournal of Wildlife Managementpublished by Wiley Periodicals, Inc. on behalf of The Wildlife Society.
Mixotrophic uptake of organic compounds by coccolithophores
Authors: Godrijan Jelena , Drapeau David , Balch William M.
Published: January 2020

Osmotrophy is one of the main modes of mixotrophic acquisition of carbon by phytoplankton, but historically it has been under‐investigated and its physiological and ecological relevance remains poorly understood. Here, we investigate osmotrophy in coccolithophores. Coccolithophores are one of the major contributors to the ocean biomass inhabiting both euphotic and subeuphotic depths in the marine environment. Coccolithophores demonstrate the potential to utilize a wide array of organic compounds in darkness. In experiments with BioLog Ecoplates, we screened a wide array of organic compounds as potential carbon sources, and observed that the major types of organic compounds taken up by coccolithophores were primarily carbohydrates along with a few amino acids and polymers. Furthermore, in subsequent radiotracer experiments, the uptake rates of14C‐labeled dissolved organic carbon compounds in the dark were low relative to the maximal rates of photosynthetic carbon fixation in the light. The time course of uptake for some compounds suggests constitutive capacity for their transport, while for others the transport appears to be activated. Nonetheless, the collective slow uptake rate of a large array of organic compounds found in seawater, might be the only way that osmotrophy could fuel significant coccolithophore growth in the deep euphotic and subeuphotic zones in the sea.
Microbial colonization of microplastics in the Caribbean Sea
Authors: Dudek Kassandra L. , Cruz Bianca N. , Polidoro Beth , Neuer Susanne
Published: January 2020

Microplastics in the ocean function as an artificial microbial reef, with diverse communities of eukaryotic and bacterial microbiota colonizing its surface. It is not well understood if these communities are specific for the type of microplastic on which they develop. Here, we carried out a 6‐week long incubation experiment of six common plastic polymers in Bocas del Toro, Panama. The community composition of prokaryotes based on 16S rRNA gene sequencing data, when judged under a null model analysis, shows that neither plastic polymer type nor time exposed to the environment plays a significant role in shaping biofilm communities. However, the null model analyses of eukaryotic communities based on 18S rRNA gene sequences reveal that they can be significantly influenced by plastic polymer type and time incubated. This was confirmed by scanning electron microscopy, which allowed us to distinguish plastic‐specific diatom communities by the end of the incubation period.
Efficient selection of copper sales contracts for small‐ and medium‐sized mining
Authors: Reus Lorenzo
Published: January 2020

The purpose of this study is to generate efficient policies for the selection and postponement of copper sales contracts by a mining company. To do so, it uses a two‐stage stochastic programming model that determines solutions considering different contract types, random prices, and risk aversion. The results show how it is possible for the selection to involve the lowest risk possible for different revenue levels required. During a period of high price volatility, an efficient solution may deliver an increase in monthly revenue of US$210,000 for a mining company that produces 50,000 tons per year, without any additional risk.
Treating and preventing recurrence of recurrent genital acquired lymphangiectasia using lymphaticovenous anastomosis at genital area: A case report
Authors: Hara Hisako , Mihara Makoto
Published: January 2020

After the simple resection of genital acquired lymphangiectasia, a high recurrence rate is reported, as lymphatic fluid from the legs to the genital region continues. Here we report a case in which we treated and prevented recurrence of recurrent genital acquired lymphangiectasia with genital lymphaticovenous anastomosis (LVA). A 48‐year‐old woman underwent hysterectomy and pelvic lymph node dissection for uterine cervical cancer at 30 years of age. The patient consulted our department for lymphedema in bilateral legs and acquired lymphangiectasia in the major labia. Despite nine attempted genital acquired lymphangiectasia resections and LVA in the lower limbs, which was aimed to prevent the recurrence, it recurred within 1–2 months postoperatively. Then we injected indocyanine green (ICG) to the bilateral edge of the anus before 10th LVA. ICG flowed from the anus to the genital area and we performed acquired lymphangiectasia resection and genital LVA on this lymphatic vessel (one anastomosis). After 6 months postoperatively, no recurrence of acquired lymphangiectasia, lymphatic leakage, or cellulitis had occurred. We found that a lymphatic flow from the anus into genital acquired lymphangiectasia occurred in one of the patients and the genital LVA, anastomosis of that responsible lymphatic vessel to the vein, might prevent genital acquired lymphangiectasia recurrence after resectional treatment.
Pattern formation of a diffusive predator‐prey model with herd behavior and nonlocal prey competition
Authors: Djilali Salih
Published: January 2020

In this paper, we study the influence of the nonlocal interspecific competition of the prey population on the dynamics of the diffusive predator‐prey model with prey social behavior. Using the linear stability analysis, the conditions for the positive constant steady state at which undergoes Hopf bifurcation, T‐H bifurcation (Turing‐Hopf bifurcation) are investigated. The Turing patterns occur in the presence of the nonlocal competition and cannot be found in the original system. For determining the dynamical behavior near T‐H bifurcation point, the normal form of the T‐H bifurcation has been used. Some graphical representations are provided to illustrate the theoretical results.
DOF‐gathering stable generalized finite element methods for crack problems
Authors: Zhang Qinghui
Published: January 2020

Generalized or eXtended finite element methods (GFEM/XFEM) have been studied extensively for crack problems. Most of the studies were concentrated on localized enrichment schemes where nodes around the crack tip are enriched by products of singular and finite element shape functions. To attain the optimal convergence rate O(h) (h is the mesh‐size), nodes in a fixed domain containing the tip have to be enriched. This results in many extra degrees of freedom (DOF) and stability issues. A so‐called DOF‐gathering GFEM/XFEM can avoid the increase of DOF, by collecting the singular enriched DOF together. Various novel modifications were designed for the DOF‐gathering GFEM/XFEM to get the optimal convergence O(h). However, they could not improve the stability, namely, condition numbers of stiffness matrices of the DOF‐gathering GFEM/XFEM could be much larger than that of the standard FEM. Motivated from the idea of stable GFEM, we propose in this paper a DOF‐gathering stable GFEM (d.g.SGFEM) for the Poisson problem with crack singularities. The main idea is to modify the singular and Heaviside enrichments by subtracting their finite element interpolants. The optimal convergence O(h) of the proposed d.g.SGFEM is proven theoretically. Moreover, the condition number of stiffness matrices of d.g.SGFEM, utilizing a local orthgonalization technique, is shown to be of same order as that of the standard FEM. Two kinds of commonly used cut‐off functions used to gather the DOF are analyzed in a unified approach. Theoretical convergence and the conditioning results of d.g.SGFEM are verified by numerical experiments.
Dual‐direction high thermal conductivity polymer composites with outstanding electrical insulation and electromagnetic shielding performance
Authors: Zhang Yang , Tang Bing , Liu Yang , Feng Rui , Song Shaokun , Xiong Chuanxi , Dong Lijie
Published: January 2020

The rapid dissipation of accumulated heat and efficient electromagnetic interference (EMI) shielding attract considerable attention due to the gradual integration and miniaturization of electronic devices. In an attempt to simultaneously overcome these issues, dual‐direction high thermal conductivity (TC) materials with outstanding electrical insulation and EMI shielding performance are urgently demanded. Herein, a tailor‐made sandwich network structure with insulated outer layer and EMI shielding middle layer is constructed by compression molding. The sandwich network structure endows the composite (#AB0.7/AM0.7/AB0.7) with high TC values of 3.051 and 3.365 Wm−1 K−1 at through‐plane and in‐plane directions, respectively, excellent electrical insulation (6.61 × 1013 Ω cm, 3.25 kV/mm) and superior EMI shielding performance (>27.68 dB from 8.2 to 12.4 GHz). All these results demonstrate that the prepared composite with tailor‐made sandwich network structure is a promising candidate as ideal thermal management material for electronic devices.
Studies on the Complexation of 3d Transition Metal Ions with NR/PEO Block Copolymer in Aqueous Medium
Authors: Mrudula Mundanayil Sasidharan , Gopinathan Nair Mazhuvadyil Ramakrishna Pillai
Published: January 2020

Polyethylene oxide (PEO) was chemically linked to natural rubber (NR) segments to form a block copolymer (BC), which proved to be a suitable material for complexing with selected first row transition metal ions in aqueous solution through batch adsorption method under noncompetitive mode. Optimum conditions for sorption were found to be 20 mmol/L initial concentration, pH at 6, ambient temperature, and 24 h. The order of decreasing adsorption capacity obtained is Mn(II) > Co(II) > Zn(II) > Ni(II) > Cu(II) > Fe(III). Freundlich isotherm shows the best fit indicating that the adsorption is of heterogeneous in nature. The complexation follows pseudo second‐order kinetics. Exothermic character of the complexation was confirmed by thermodynamic study. For all metal ions, the standard free energy change values are negative for the different temperatures studied, which confirms the spontaneous character of the process. At ambient temperature, the free energy change lies between −2.35 and − 7.83 kJ/mol for all complexes. Values of activation energy for all the metal ion complexation is within the range 11–25 kJ/mol, which indicates chemical interaction via activated physico–chemical adsorption. Variation in stability constant of the complexes also follows the same order as given above. POLYM. ENG. SCI., 60:661–672, 2020. © 2020 Society of Plastics Engineers
Study of C─H⋯O Bond of Organic–Inorganic Hybrids Based on Polyhydroxybutyrate and Oxides Obtained Via an In Situ Sol–Gel Route
Authors: Martinez Martinez Toledo Anna Lecticia , da Rocha Rodrigues Elton Jorge , Dutra Filho José Carlos , de Souza Aguiar dos Santos Domethila Mariano , Marques Suelen Adriani , Bruno Tavares Maria Inês
Published: January 2020

Sol–gel‐based zirconia (ZrO2) and silica (SiO2) were obtained in situ via hydrolysis–polycondensation of metal alkoxide precursors in membranes of poly(3‐hydroxybutyrate) (PHB). What followed was an assessment of thermal and spectroscopic effects from the insertion of the inorganic network in the PHB matrix. The findings exhibited a dependence of both the concentration and the chemical nature of the precursor on the properties of the as‐formed inorganic–organic hybrids. The results also indicated that positive nucleating effects, a reduction of the crystallite size and a variation in thermal transitions correlate with spectroscopic data from the alpha and beta crystal forms of the PHB matrix, as well as the crystallization data obtained through polarized light microscopy. POLYM. ENG. SCI., 60:673–681, 2020. © 2020 Society of Plastics Engineers
VH‐VL interdomain dynamics observed by computer simulations and NMR
Authors: Fernández‐Quintero Monica L. , Hoerschinger Valentin J. , Lamp Leonida M. , Bujotzek Alexander , Georges Guy , Liedl Klaus R.
Published: January 2020

The relative orientation of the two variable domains, VH and VL, influences the shape of the antigen binding site, that is, the paratope, and is essential to understand antigen specificity. ABangle characterizes the VH‐VL orientation by using five angles and a distance and compares it to other known structures. Molecular dynamics simulations of antibody variable domains (Fvs) reveal fluctuations in the relative domain orientations. The observed dynamics between these domains are confirmed by NMR experiments on a single‐chain variable fragment antibody (scFv) in complex with IL‐1β and an antigen‐binding fragment (Fab). The variability of these relative domain orientations can be interpreted as a structural feature of antibodies, which increases the antibody repertoire significantly and can enlarge the number of possible binding partners substantially. The movements of the VH and VL domains are well sampled with molecular dynamics simulations and are in agreement with the NMR ensemble. Fast Fourier transformation of the ABangle metrics allows to assign timescales of 0.1‐10 GHz to the fastest collective interdomain movements. The results clearly show the necessity of dynamics to understand and characterize the favorable orientations of the VH and VL domains implying a considerable binding interface flexibility and reveal in all antibody fragments (Fab, scFv, and Fv) very similar VH‐VL interdomain variations comparable to the distributions observed for known X‐ray structures of antibodies.

Significance Statement

Antibodies have become key players as therapeutic agents. The binding ability of antibodies is determined by the antigen‐binding fragment (Fab), in particular the variable fragment region (Fv). Antigen‐binding is mediated by the complementarity‐determining regions consisting of six loops, each three of the heavy and light chain variable domain VH and VL. The relative orientation of the VH and VL domains influences the shape of the antigen‐binding site and is a major objective in antibody design. In agreement with NMR experiments and molecular dynamics simulations, we show a considerable binding site flexibility in the low nanosecond timescale. Thus we suggest that this flexibility and its implications for binding and specificity should be considered when designing and optimizing therapeutic antibodies.
Gender differences in speed of advancement: An empirical examination of top executives in the Fortune 100 firms
Authors: Bonet Rocio , Cappelli Peter , Hamori Monika
Published: January 2020

Research summary

We examine the advancement of women in executive roles in the ranks of the 10 highest executive positions in the Fortune 100 companies in 2001 and 2011. We find that women executives secured top executive positions faster than men, controlling for relevant individual attributes, and that the advantage of women with respect to men grew with the number of years they spent in the organization. The female advantage disappeared once companies had more than one high‐ranking female executive. We make use of several tests to assess possible unobserved differences between men and women executives, including the case–control technique from epidemiology. Our results are consistent with institutional pressures accelerating women's advancement to top executive positions, but they also reveal the limited effectiveness of such pressures.

Managerial summary

Employers interested in increasing the diversity of their executive ranks should pay attention not only to who is in those jobs but also how long it took them to get there. In our study, women in top jobs got there faster not just because they were better but because they moved through previous positions faster and skipped steps in job ladders. This suggests how diversity at the top can be enhanced without having to wait for more diverse cohorts in lower‐level jobs to slowly advance. The fact that faster advancement slowed once there were a few women in top jobs suggests that support for advancement was indeed a company choice, unfortunately one driven by public appearances.
Effect of pessary cleaning and optimal time interval for follow-up: a prospective cohort study
Authors: Thys Susanne D. , Hakvoort Robert A. , Asseler Joyce , Milani Alfredo L. , Vollebregt Astrid , Roovers Jan Paul
Published: January 2020

Introduction and hypothesis

The objective of this study was to determine the efficacy of routine follow-up visits for pessary cleaning, the effect of extended time intervals between visits and the proportion of patients being able to self-manage their pessary for pelvic organ prolapse (POP).

Methods

We conducted a prospective cohort study in patients with a stage ≥II POP without previous POP surgery. All patients received a pessary as primary treatment. Our main outcome measure was a difference ≥2 in median visual analogue scale (VAS) scores (for pain, discharge, irritation) 1 week before and 1 week after cleaning. Measurements were performed after 3- and 9-month cleaning intervals. For the evaluation of the effect of cleaning, 132 patients (3 months’ follow-up) and 87 patients (12 months’ follow-up) were available for analysis. For the evaluation of the effect of the lengthening interval, 123 patients were available.

Results

Self-management was performed in 45.2% of patients at 1 year. In 93.1% of patients, no differences were observed in pre-and post-cleaning VAS scores (effect of cleaning) on vaginal pain. Nor was there a difference in discharge (72.4%) or irritation 85.1% (p = 0.00). No differences were observed in pre-cleaning VAS scores for vaginal pain, discharge and irritation when the interval was lengthened from 3 to 9 months. No serious adverse events occurred.

Conclusions

There is no proven benefit of regular follow-up visits to clean a pessary. Also, the length of the cleaning interval does not seem to matter.
Buprenorphine–cannabis interaction in patients undergoing opioid maintenance therapy
Authors: Vierke Christopher , Marxen Brigitte , Boettcher Michael , Hiemke Christoph , Havemann-Reinecke Ursula
Published: January 2020

Buprenorphine is a partial μ-opioid agonist widely used for opioid maintenance therapy (OMT). It is mainly metabolized to pharmacologically active norbuprenorphine by the cytochrome P450 (CYP) isozyme 3A4. This may give rise to drug–drug interactions under combinations with inhibitors or inducers of CYP3A4. Cannabis is a potential inhibitor of CYP3A4, and there is a large degree of concomitant cannabis use among OMT patients. We performed a retrospective analysis on liver healthy OMT patients substituted with buprenorphine, either with (n = 15) or without (n = 17) concomitant use of cannabis. Patients with additional illicit drugs or medications affecting CYP3A were excluded. Measured blood concentrations of buprenorphine and norbuprenorphine were compared between the two groups. Cannabis users and non-users received similar doses, but users had 2.7-fold higher concentrations of buprenorphine (p < 0.01) and 1.4-fold for norbuprenorphine (1.4-fold, p = 0.07). Moreover, the metabolite-to-parent drug ratio was 0.98 in non-users and 0.38 in users (p = 0.02). Female gender did not produce significant effects. These findings indicate that cannabis use decreases the formation of norbuprenorphine and elevates buprenorphine and norbuprenorphine concentrations in blood most probably by inhibition of CYP3A4. The pharmacokinetic interaction may give rise to enhanced or altered opioid activity and risk of intoxications. Physicians should inform patients about this risk and supervise cannabis users by regular control of buprenorphine blood levels, i.e., by therapeutic drug monitoring.