bluuebunny/crossref_metadata_2025 huggingface dataset:
Inter‐comparison of methods to homogenize daily relative humidity
Authors: Chimani Barbara , Venema Victor , Lexer Annemarie , Andre Konrad , Auer Ingeborg , Nemec Johanna
Published: March 2018

Three homogenization methods (ACMANT, MASH and HOMOP) have been evaluated for their efficiency in homogenizing daily relative humidity data. A homogeneous surrogate data set based on Austrian stations was created and perturbed to simulate inhomogeneous, realistic time series (“validation data sets”). Two validation data sets (“simple” and “complex”) were created. In both data sets the magnitude of the breaks depends on the time of year and the measured values. They differ in the number of missing values and especially on whether the break signal was perturbed by white noise. In the latter case, the noise also changed to take into account changes in random measurements errors and other physical factors. The evaluation showed high agreement in statistical characteristics between the real data and the surrogate data set. The homogenization methods were compared in their ability both to detect breaks and to reproduce the homogeneous surrogate data set. For the evaluation of the final data set the distribution, trends and root‐mean‐square error (RMSE) were analysed. The percentage of improved time series depends on the evaluation parameter considered. Less stations were improved when using the “complex” validation data set. Because of the large number of breaks and the small signal‐to‐noise ratio, an improvement of the data by homogenization was non‐ideal for all methods used, with each having its advantages and disadvantages. The quality of the ACMANT and HOMOP methods is comparable, with ACMANT solving less stations but declaring less stations falsely as homogeneous. To get an impression of the influence on real data, ACMANT was applied to homogenize daily Austrian time series of relative humidity. While the quality of data from some stations can be improved through the homogenization, this is not the case for all time series. A final evaluation of homogenized time series should be performed to ensure their quality before further use.
Time‐sensitive analysis of a warming climate on heat waves in Saudi Arabia: Temporal patterns and trends
Authors: Alghamdi Ali S. , Harrington John
Published: March 2018

The climate of the Middle East is warming and extreme hot temperature events are becoming common, as observed by the significant upwards trends in mean and extreme temperatures during the last few decades. Climate modelling studies suggest that the frequency, intensity, and duration of extreme temperature events are expected to increase as the global and local climate continues to warm. However, most of the literature about heat waves (HWs) in Saudi Arabia provides information about the duration aspect using a single index, with no detailed information about frequency and intensity aspects. To help establish a baseline for understanding past and future change, this study explored the temporal behaviour(s) of the frequency, duration, and intensity of HWs in Saudi Arabia under the observed recent climate change. Several issues are addressed including some methodological concerns associated with the commonly used heat wave index, data quality control, and statistical analysis. A new definition and method to detect HWs and their changes is proposed, considering the ongoing effects of climate warming and the subtropical arid climate.

A HW event is defined as a period of two or more consecutive days (i.e., at least 48 hr) with a daily maximum and minimum temperature exceeding the 90th and 85th percentiles of the maximum and minimum, respectively. Threshold percentiles were calculated monthly and adjusted for each decade of analysis. For temporal trend analyses, we consider HW events and their duration as count data using different Poisson models for analysis. HW frequency, intensity, and duration across Saudi Arabia were found to behave geographically and temporally differently across the 25 stations studied. Distinct temporal and geographical patterns were observed indicating a confounding interplay of regional and local factors, such as urbanization, elevation, latitude, and distance from a large body of water.
Quantify contribution of aerosol errors to cloud fraction biases in CMIP5 Atmospheric Model Intercomparison Project simulations
Authors: Fan Tianyi , Zhao Chuanfeng , Dong Xiquan , Liu Xiaohong , Yang Xin , Zhang Fang , Shi Chunming , Wang Yuying , Wu Fang
Published: March 2018

Identifying the error sources in total cloud fraction (CF) simulated by global climate models is essential for improving climate prediction. This study investigates if and how significant the aerosol simulation errors contribute to the model CF biases in the Atmosphere Model Inter‐comparison Project (AMIP) simulations of the Coupled Model Inter‐comparison Project Phase 5 (CMIP5) models. The aerosol optical depths (AODs) and CFs in 12 CMIP5/AMIP models have been examined and compared with 8‐year moderate resolution imaging spectroradiometer (MODIS) satellite observations. The results show that the global‐averaged multi‐model ensemble mean AOD and CF, which are .14 and 56.2%, are 22.2 and 15.2% lower than those from MODIS, respectively. The simulated relationship between AOD and CF generally agrees with the observation on the global scale but differs on regional scale. Based on the “conditional sampling approach,” the AOD simulation errors that affect the CF biases of the models were separated from the model biases caused by the aerosol–CF errors that are related to dynamics, thermodynamics, and microphysics. It is found that the AOD errors barely contribute to the CF biases for most CMIP5/AMIP models on the global scale. Instead, simulated aerosol–CF errors are still the major contributors to the CF biases. However, we should note that AOD biases contribution in some regions, such as south Indian Ocean, Asia, Europe, and North Pacific Ocean, cannot be ignored. We also found that with increasing cloud liquid water path the CF does not increase with AOD as sensitively in the CMIP5/AMIP models as in the MODIS observations.
Bias correction of the observed daily precipitation and re‐division of climatic zones in China
Authors: Li Na , Li Yi , Yao Ning
Published: March 2018

Using accurate precipitation data is critical to climate and hydrology research, but current studies have found that the precipitation measured by various standard precipitation gauges (P
m) is much smaller than actual precipitation and there is a necessity to conduct bias correction before using the gauge‐measured precipitation (P
m) data. Using the daily P
m, wind speed and temperature data from 553 weather stations in China over 1961–2015, the wind‐induced error (
∆PDL), trace precipitation (ΔP
t) and wetting loss (ΔP
w) and the corrected precipitation (P
c) were systematically estimated. Consequently, the originally P
m‐based climate zone division changed after the precipitation bias correction. The climate zone re‐division was conducted using four P
c‐based indices, that is, annual mean precipitation Erinc's index
I
m, Sahin's index
Ish and the United Nations Environment Programme (UNEP) aridity index I
A. The results showed that annual mean correction amounts () over 1961–2015 varied between 40.5 and 600.2 mm with the average value of 146.2 mm in China. The ranges of annual mean values of was 11.6–35.3 mm with an average of 24.8 mm, of was 3.6–74.2 mm with an average of 34.07 mm and of was 1.4–525.7 mm with an average of 87.3 mm, respectively. The spatial distribution of decreased from the northwest to the southeast. Annual was generally smaller than 100 mm in northwestern China, but greater than 150 mm in southeastern China. By climate zone re‐division, the areas of severe arid decreased but the areas of severe humid areas increased, which indicated that actual climate conditions of China should be wetter than present assessment results. In conclusion, the bias correction indicated that a corrected climate zone division should be referred in future climatic change research.
Application of Latent Semantic Analysis to Divergent Thinking is Biased by Elaboration
Authors: Forthmann Boris , Oyebade Oluwatosin , Ojo Adebusola , Günther Fritz , Holling Heinz
Published: March 2018

Scoring divergent‐thinking response sets has always been challenging because such responses are not only open‐ended in terms of number of ideas, but each idea may also be expressed by a varying number of concepts and, thus, by a varying number of words (elaboration). While many current studies have attempted to score the semantic distance in divergent‐thinking responses by applying latent semantic analysis (LSA), it is known from other areas of research that LSA‐based approaches are biased according to the number of words in a response. Thus, the current article aimed to identify and demonstrate this elaboration bias in LSA‐based divergent‐thinking scores by means of a simulation. In addition, we show that this elaboration bias can be reduced by removing the stop words (for example, and, or, for and so forth) prior to analysis. Furthermore, the residual bias after stop word removal can be reduced by simulation‐based corrections. Finally, we give an empirical illustration for alternate uses and consequences tasks. Results suggest that when both stop word removal and simulation‐based bias correction are applied, convergent validity should be expected to be highest.
Fast microplastics identification with stimulated Raman scattering microscopy
Authors: Zada Liron , Leslie Heather A. , Vethaak A. Dick , Tinnevelt Gerjen H. , Jansen Jeroen J. , de Boer Johannes F. , Ariese Freek
Published: March 2018

The abundance of plastic products in modern society has resulted in a proliferation of small plastic particles called “microplastics” in the global environment. Currently, spectroscopic techniques such as Fourier‐transform infrared and spontaneous (i.e., conventional) Raman spectroscopy are widely employed for the identification of the plastic microparticles, but these are rather time consuming. Stimulated Raman scattering (SRS) microscopy, based on the coherent interaction of 2 different laser beams with vibrational levels in the molecules of the sample, would enable much faster detection and identification of microplastics. Here, we present for the first time an SRS‐based method for identifying 5 different high production‐volume polymer types in microplastics extracted from environmental or consumer product samples. The particles from the extracts were collected on a flat alumina filter, and 6 SRS images were acquired at specifically chosen wavenumbers. Next, we decomposed these spectral data into specific images for the 5 polymers selected for calibration. We tested the approach on an artificial mixture of plastic particles and determined the signal‐to‐noise and level of cross talk for the 5 polymer types. As a proof of principle, we identified polyethylene terephthalate particles extracted from a commercial personal care product, demonstrating also the thousand‐fold higher speed of mapping with SRS compared with conventional Raman. Furthermore, after density separation of a Rhine estuary sediment sample, we scanned 1 cm2 of the filter surface in less than 5 hr and detected and identified 88 microplastics, which corresponds to 12,000 particles per kilogram dry weight. We conclude that SRS can be an efficient method for monitoring microplastics in the environment and potentially many other matrices of interest.
A SERS method for thermal neutron detection
Authors: Sun Jie , Wang Kaikai , Han Shuyan , Zhang Mingyue , Wang Ying , Qian Weiping , Zhang Haiqian , Dong Jian
Published: March 2018

To achieve the surface‐enhanced Raman scattering (SERS) method for thermal neutron detection, 4‐mercaptophenylboronic acid (4‐MPBA), a natural boron‐containing and high intrinsic Raman‐active compound, was used as a detection material, and after the fission of boron‐10(10B) isotope capturing thermal neutrons, parts of 4‐MPBA molecules were converted into thiophenol. Based on SERS substrates of gold nanoshells, the conversion was sensitively quantitative by SERS spectra of the two molecules to indicate the dose of thermal neutrons. The conversion was proportional to the radiation time and reversely proportional to the distance to the radiation source. The detection limit is 5.6 μGy and 33.6 μGy corresponding to the 4‐MPBA adsorbed on solid‐phase substrates and dissolved in solvent, respectively. The SERS method for thermal neutron detection would provide a simple and new way for neutrons utilization, administration, and radiation protection.
Hydration properties and water structure in aqueous solutions of native and modified cyclodextrins by UV Raman and Brillouin scattering
Authors: Bottari C. , Comez L. , Paolantoni M. , Corezzi S. , D'Amico F. , Gessini A. , Masciovecchio C. , Rossi B.
Published: March 2018

We have studied aqueous solutions of native and chemically modified cyclodextrins (CDs) by means of UV Raman and Brillouin scattering. Analysis of the spectral profile of the OH‐stretching Raman signal, which is sensitive to the intermolecular organization of water, reveals a remarkable reduction of the population of ordered tetrahedral water structures inside the hydration shell of substituted CDs. As a remarkable result, this destructuring effect seems to be mainly related to the number of substituted hydroxyl groups in the CD ring rather than to the chemical nature of the substituent group. UV Brillouin scattering experiments confirm the structural picture emerging from the UV Raman study, also providing an estimate of the activation energy associated to the collective H‐bond restructuring mechanism in CD solutions. Overall, the results provide a coherent description of the water–solute interactions in aqueous solutions of CDs.
Concentrates of triterpenic acids obtained from crude olive pomace oils: characterization and evaluation of their potential antioxidant activity
Authors: Velasco Joaquín , Holgado Francisca , Márquez‐Ruiz Gloria , Ruiz‐Méndez María Victoria
Published: March 2018

Background

Pentacyclic triterpenic acids (TA) are phytochemicals of increasing nutritional interest owing to their bioactive properties, such as anti‐inflammatory, antitumoral, antihyperglycemic and hepatoprotective. Crude olive pomace oils constitute a non‐exploited significant source of these compounds. In the present study, concentrates of TA were extracted and characterized from crude olive pomace oils that were obtained by centrifugation and subsequent solvent extraction, respectively. Specifically, the concentrates were obtained from the byproduct generated in the filtration of the oils. The solids were subjected to Soxhlet extractions with hexane to remove the residual oil and then with ethanol for the TA extraction.

Results

Concentrates containing 850–980 g kg−1 TA were isolated from the oils obtained by centrifugation, whereas those isolated from oils obtained by hexane extraction presented levels of TA that ranged from 510 to 900 g kg−1. Oleanolic (OA) and maslinic (MA) acids were the TA found in the concentrates. The relative contents of OA and MA were, respectively, 30:70 (w/w) and 77:23 (w/w). All concentrates also presented phenolic compounds at levels of g kg−1 and displayed slight antioxidant properties.

Conclusion

Concentrates of TA, containing MA and OA, can be readily obtained from a byproduct generated by filtration of crude olive pomace oils. Concentrates isolated from oils obtained by centrifugation were rich in MA, whereas those from oils extracted with hexane were rich in OA. The concentrates showed slight antioxidant properties that can be mainly attributed to the presence of phenolic compounds and not to TA. © 2018 Society of Chemical Industry
Effects of ethrel, 1‐MCP and modified atmosphere packaging on the quality of ‘Wonderful’ pomegranates during cold storage
Authors: Valdenegro Mónika , Huidobro Camila , Monsalve Liliam , Bernales Maricarmen , Fuentes Lida , Simpson Ricardo
Published: March 2018

BACKGROUND

Pomegranate (Punica granatum) is a non‐climacteric fruit susceptible to chilling injury (CI) at temperatures below 5 °C. To understand the influences of ethylene and modified atmosphere on CI physiological disorders of pomegranate, exogenous ethrel (0.5, 1 and 1.5 µg L−1) treatments, 1‐methylcyclopropene (1‐MCP) (1 µL L−1) exposure, packaging in a modified atmosphere (MAP) (XTend™ bags; StePac, São Paulo, Brazil), a MAP/1‐MCP combination, and packaging in macro‐perforated bags (MPB) were applied. The treated fruits were cold stored (2 ± 1 °C; 85% relative humidity) and sampled during 120 + 3 days at 20 °C.

RESULTS

During cold storage, CI symptoms started at 20 days in MPB and at 60 days for all exogenous ethylene treatments, and were delayed to 120 days in MAP, 1‐MCP and MAP/1‐MCP treatments. MPB and ethylene treatments induced significant electrolyte leakage, oxidative damage, lipid peroxidation, ethylene and CO2 production, and 1‐aminocyclopropane‐1‐carboxylic acid oxidase activity, without any change in total soluble solids, titratable acidity or skin and aril colours. Conversely, MAP by itself, or in combination with 1‐MCP application, effectively delayed CI symptoms.

CONCLUSION

During long‐term cold storage of this non‐climacteric fruit, ethrel application induced endogenous ethylene biosynthesis, accelerating the appearance of CI symptoms in contrast to the observations made for MAP and 1‐MCP treatments. © 2018 Society of Chemical Industry
Effect of NaHCO3 treatments on the activity of cell‐wall‐degrading enzymes produced by Penicillium digitatum during the pathogenesis process on grapefruit
Authors: Venditti Tullio , D'hallewin Guy , Ladu Gianfranca , Petretto Giacomo L , Pintore Giorgio , Labavitch John M
Published: March 2018

BACKGROUND

This study was performed to clarify the strategies of Penicillium digitatum during pathogenesis on citrus, assessing, on albedo plugs, the effects of treatment with sodium bicarbonate (NaHCO3), at two different pH values (5 and 8.3), on cell‐wall‐degrading enzyme activity over a period of 72 h.

RESULTS

Treatment with NaHCO3, under alkaline pH, delayed the polygalacturonase activity for 72 h, or 48 h in the case of the pectin lyase, compared with the control or the same treatment at pH 5. In contrast, pectin methyl esterase activity rapidly increased after 24 h, in plugs dipped in the same solution. In this case, the activity remained higher than untreated or pH 5‐treated plugs up to 72 h.

CONCLUSION

The rapid increase in pectin methyl esterase activity under alkaline conditions is presumably the strategy of the pathogen to lower the pH, soon after the initiation of infection, in order to restore an optimal environment for the subsequent polygalacturonase and pectin lyase action. In fact, at the same time, a low pH delayed the enzymatic activity of polygalacturonase and pectin lyase, the two enzymes that actually cleave the α‐1,4‐linkages between the galacturonic acid residues. © 2018 Society of Chemical Industry
Duct‐to‐mucosa versus dunking techniques of pancreaticojejunostomy after pancreaticoduodenectomy: Do we need more trials? A systematic review and meta‐analysis with trial sequential analysis
Authors: Kilambi Ragini , Singh Anand Narayan
Published: March 2018

Background

Pancreaticojejunostomy (PJ is the most widely used reconstruction technique after pancreaticoduodenectomy. Despite several randomized trials, the ideal technique of pancreaticojejunostomy remains debatable. We planned a meta‐analysis of randomized trials comparing the two most common techniques of PJ (duct‐to‐mucosa and dunking) to identify the best available evidence in the current literature.

Methods

We searched the Pubmed/Medline, Web of science, Science citation index, Google scholar and Cochrane Central Register of Controlled Trials electronic databases till October 2017 for all English language randomized trials comparing the two approaches. Statistical analysis was performed using Review Manager (RevMan), Version 5.3. Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014 and results were expressed as odds ratio for dichotomous and mean difference for continuous variables. P‐value ≤ 0.05 was considered significant. Trial sequential analysis was performed using TSA version 0.9.5.5 (Copenhagen: The Copenhagen Trial Unit, Center for Clinical Intervention Research, 2016).

Results

A total of 8 trials were included, with a total of 1043 patients (DTM: 518; Dunking: 525). There was no significant difference between the two groups in terms of overall as well as clinically relevant POPF rate. Similarly, both groups were comparable for the secondary outcomes. Trial sequential analysis revealed that the required information size had been crossed without achieving a clinically significant difference for overall POPF; and though the required information size had not been achieved for CR‐POPF, the current data has already crossed the futility line for CR‐POPF with a 10% risk difference, 80% power and 5% α error.

Conclusion

This meta‐analysis found no significant difference between the two techniques in terms of overall and CR‐POPF rates. Further, the existing evidence is sufficient to conclude lack of difference and further trials are unlikely to result in any change in the outcome. (CRD42017074886).
Minimally invasive versus open pancreatic enucleation. Systematic review and meta‐analysis of surgical outcomes
Authors: Guerra Francesco , Giuliani Giuseppe , Bencini Lapo , Bianchi Paolo P. , Coratti Andrea
Published: March 2018

Parenchymal sparing procedures are gaining interest in pancreatic surgery and recent studies have reported that minimally invasive pancreatic enucleation may be associated with enhanced outcomes when compared with traditional surgery. By meta‐analyzing the available data from the literature, minimally invasive surgery is not at higher risk of pancreatic fistula and offers a number of advantages over conventional surgery for pancreatic enucleation.
Impact of histological subtype on the prognosis of patients undergoing surgery for colon cancer
Authors: Bagante Fabio , Spolverato Gaya , Beal Eliza , Merath Katiuscha , Chen Qinyu , Akgül Ozgür , Anders Robert A. , Pawlik Timothy M.
Published: March 2018

Background

The effect of the histological subtype on the prognosis of patients undergoing surgery for colon cancer (CC) is not completely understood.

Methods

The Surveillance, Epidemiology, and End Results (SEER) 2004–2014 database was used to compare the long‐term outcomes of patients undergoing colon resection for classical adenocarcinoma (CA), mucinous adenocarcinoma (MUC), and signet‐cell adenocarcinoma (SC).

Results

A total of 153 317 (89%) patients had CA, 16 660 (10%) MUC while 1810 (1%) patients had SC subtype. Patients with MUC and SC more frequently had a poorly differentiated CC and were more likely to present with advanced disease compared with CA patients (P < 0.001). Patients with CA had a 5‐year OS of 62% versus 55% and 34% for patients with MUC and SC subtypes, respectively (P = 0.001). On multivariable analysis, site of cancer, tumor grade, and TNM stage were associated with prognosis (all P < 0.001). After controlling for these risk factors, patients with MUC (HR, 1.09, P < 0.001) and SC (HR, 1.47, P < 0.001) had a roughly 10% and 50% increased hazard of death, respectively, compared with CA patients.

Conclusions

MUC and SC are distinct subtypes of CC associated with a worse prognosis. These data can help inform discussion about prognosis and possibly direct adjuvant management.
Hospital volume and short‐term outcomes after cytoreductive nephrectomy
Authors: Xia Leilei , Strother Marshall C. , Taylor Benjamin L. , Chelluri Raju R. , Pulido Jose E. , Guzzo Thomas J.
Published: March 2018

Purpose

To investigate the impact of hospital volume on short‐term outcomes after cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC).

Methods

We identified mRCC patients who underwent CN from 2006 to 2013 in the National Cancer Database. Annual hospital CN volume was categorized as high (top 20th percentile) and low. Multivariable logistic regressions were used to compare 30‐day mortality, 90‐day mortality, prolonged length of stay (PLOS, ≥7 days), and 30‐day readmission rates. Sensitivity analyses were performed with hospital volume considered as a continuous variable.

Results

A total of 9789 patients were included with high‐volume (n = 1916) defined as ≥8 cases and low‐volume (n = 7873) as 1‐7 cases annually. Multivariable logistic regression showed that high‐volume was associated with lower odds of 30‐day mortality (OR = 0.69, P = 0.013), 90‐day mortality (OR = 0.65, P < 0.001), PLOS (OR = 0.82, P = 0.002), and 30‐day readmission (OR = 0.78, P = 0.028). Sensitivity analyses showed that increasing hospital volume (per case) was associated with lower odds of 30‐day mortality (OR = 0.965, P = 0.008), 90‐day mortality (OR = 0.966, P < 0.001), PLOS (OR = 0.982, P = 0.001), and 30‐day readmission (OR = 0.975, P = 0.012).

Conclusion

Higher hospital volume was associated with better short‐term outcomes after CN. Future studies are needed to validate our findings and explore the potential components leading to better outcomes in the higher volume hospitals.
Predicting potential agritourism segments on the basis of combined approach: The case of Qazvin, Iran
Authors: Varmazyari Hojjat , Asadi Ali , Kalantari Khalil , Joppe Marion , Rezvani Mohammad Reza
Published: March 2018

Most published rural/agritourism segmentation studies were undertaken in the 1990s and 2000s and concentrated on developed countries. This study predicts tourist segments by surveying a sample of potential agricultural tourists in Qazvin, Iran. Qazvin is capital of the province of the same name and is in a unique position for agritourism development, due to its very important historical, natural, and agricultural attractions. A factor‐clustering method and combined approach identified 3 distinct agritourists segments, one of whom not previously described, who exhibited the greatest concern for food safety. The study presents a spectrum of agritourists needs that allow us to compare the priorities of agritourists in emerging markets with those of industrialized countries.
What makes a museum attractive to young people? Evidence from Italy
Authors: Manna Rosalba , Palumbo Rocco
Published: March 2018

The museums' ability to attract young people is drawing the increasing interest of scholars and practitioners. However, little is known about the factors that influence the museums' attractiveness to young audience. To fill such a gap, this paper investigates the entire population of Italian museums (N = 4.967). A quantile regression model was used, in order to identify the variables that positively affected young people's visits to Italian museums. The research findings suggested that museums should devise tailored strategies to attract young people. Digital tools, interorganizational relationships, and ancillary services were found to be respectively critical for small‐sized, medium‐sized, and big‐sized museums.
High–Frame Rate Vector Flow Imaging of the Carotid Bifurcation in Healthy Adults: Comparison With Color Doppler Imaging
Authors: Goddi Alfredo , Bortolotto Chandra , Raciti Maria Vittoria , Fiorina Ilaria , Aiani Luca , Magistretti Giovanni , Sacchi Andrea , Tinelli Carmine , Calliada Fabrizio
Published: March 2018

Objectives

To evaluate the carotid bifurcation in healthy adults using a commercial system equipped with high–frame rate vector flow imaging (VFI) based on the plane wave and to compare VFI with color Doppler imaging.

Methods

Carotid bifurcation diameters and flow characteristics of 60 vessels in 60 healthy volunteers were evaluated quantitatively and qualitatively to assess complex flow patterns and their extension and duration.

Results

Complex flow in the internal carotid artery (ICA) was associated with a statistically significant difference in the ΔICA sinus‐to‐common carotid artery (CCA) diameter ratio (the relative change in diameter between the CCA and ICA sinus.) Vector flow imaging and color Doppler imaging were in accordance when detecting complex flow in 96.7% of cases; in 3.3% of cases, only VFI identified small recirculation areas of short duration. Vector flow imaging highlighted a larger extension of the complex flow (mean ± SD, 47.7 ± 28.5 mm2; median, 45.5 mm2) compared with color Doppler imaging (mean, 29.2 ± 19.9 mm2; median, 29.5 mm2) and better depicted different complex flow patterns; a strong correlation (r = 0.84) was found between the ΔICA sinus‐to‐CCA diameter ratio and the complex flow extension. Vector flow imaging showed a longer duration of the flow disturbances (mean, 380 ± 218 milliseconds; median, 352.5 milliseconds) compared with color Doppler imaging (mean, 325 ± 206 milliseconds; median, 333 milliseconds), and there was a strong correlation (r = 0.92).

Conclusions

Vector flow imaging is as effective as color Doppler imaging in the detection of flow disturbances, but it is more powerful in the assessment of complex flow patterns.
A Reliable Method for Quantification of Tendon Structure Using B‐Mode Ultrasound
Authors: Hullfish Todd J. , Baxter Josh R.
Published: March 2018

Structure is an important clinical marker of tendon health; however, current standards use qualitative scores that are not strongly reliable. Therefore, the purpose of this study was to establish the reliability of an image‐processing technique that quantifies tendon collagen structure using B‐mode ultrasound images. Longitudinal images of the Achilles tendon were collected in 12 healthy young adults, and intra‐ and inter‐rater reliability was assessed over multiple image selections and multiple days. Intraclass correlation coefficients were strong (r ≥ 0.71) for all comparisons. These findings demonstrate that quantitative assessments of tendon structure using B‐mode ultrasound are reliable.
Ultrasound and the Evaluation of Pediatric Thyroid Malignancy: Current Recommendations for Diagnosis and Follow‐up
Authors: Ogle Sarah , Merz Alexa , Parina Ralitza , Alsayed Mahmoud , Milas Mira
Published: March 2018

Ultrasound (US) plays a critical role in the evaluation, treatment, screening, and surveillance of thyroid malignancy in pediatric patients. This review aims to summarize recent advances in this topic. Improvements in imaging technology have amplified the advantage of US and US‐guided fine‐needle aspiration biopsy for thyroid nodule evaluation, cancer diagnosis, and surgical planning. Ultrasound has a definitive screening role for early cancer detection in high‐risk patients, including those with a history of radiation exposure from childhood treatments, environmental radiation disasters, or hereditary/familial cancer syndromes. Finally, US is a key component of lifelong surveillance for recurrence among pediatric thyroid cancer survivors.
Monitoring Morphologic Changes in Male Rowers Using Limited Portable Echocardiography Performed by a Frontline Physician
Authors: Kerkhof Deanna L. , Lucas Caroline , Corrado Gianmichel D.
Published: March 2018

Athletes' hearts have been studied for adaptive changes in response to exercise. Physiologic changes are normal responses to intense athletic training regimens, whereas pathologic changes predispose athletes to sudden cardiac death. The two alterations overlap in clinical presentation. Research continues to investigate the upper limits of cardiac remodeling to aid clinical decision making. Studying normal changes that occur in response to exercise will advance physicians' understanding of physiologic responses to exercise and potentially improve clinical distinction. To expand this body of knowledge, we present an observational case series that describes morphologic changes in athlete's hearts concurrent with performance measurements.
A Practical Approach to Quantitative Grayscale Ultrasound Analysis of Hepatic Steatosis in Pediatric Patients Using a Picture Archiving and Communication System–Based Tool
Authors: Erdem Toslak Iclal , Lim‐Dunham Jennifer E. , Joyce Cara , Marbella Marko E.
Published: March 2018

Objectives

To evaluate the efficacy of a picture archiving and communication system (PACS)‐based ultrasound (US) quantification technique for diagnosis of hepatic steatosis in a pediatric population.

Methods

Abdominal US images of 49 pediatric patients (≤18 years) with histopathologically proven diagnoses of hepatic steatosis (n = 17), nonsteatotic liver disease (n = 19), and a normal liver (n = 13) were retrospectively reviewed. Patient demographics, the fibrosis stage, and the steatosis grade were obtained from the database. Quantitative grayscale measurements of the echo intensity level of the liver and kidneys were performed on the US images using the PACS measuring tool. The hepatorenal ratio was obtained by dividing mean liver by mean kidney values. The heterogeneity index for the liver was calculated by dividing the liver standard deviation by mean liver values. Hepatorenal ratio and heterogeneity index values of the 3 groups were correlated with pathologic results and compared by a 1‐way analysis of variance. A receiver operating characteristic curve analysis was performed, and cutoff values were determined.

Results

The hepatorenal ratio of the hepatic steatosis group was significantly greater than those of the control and nonsteatotic liver disease groups (P < .001). The heterogeneity index of the hepatic steatosis group was significantly greater than that of the control group (P = .046). For a hepatorenal ratio cutoff value of 1.5, 88.2% sensitivity, 91.4% specificity, 88.3% positive predictive value, and 94.1% negative predictive value were obtained for predicting hepatic steatosis.

Conclusions

PACS‐based quantitative grayscale US quantification is a safe, accurate, and easily applicable objective method for the diagnosis of hepatic steatosis in children. A hepatorenal ratio of greater than 1.5 can be used as a conservative parameter, permitting increased confidence in discriminating hepatic steatosis from other conditions.
Axillary Sonography of the Shoulder: An Adjunctive Approach
Authors: Michelin Paul , Legrand Julie , Lee Kenneth S. , Leleup Grégoire , Etancelin Mathilde , Banse Christopher , Dacher Jean‐Nicolas , Duparc Fabrice
Published: March 2018

Sonography of the shoulder is widely used to assess various disorders, including tendinous diseases of the rotator cuff and the long head of the biceps brachii muscle. The shoulder is commonly explored through anterior, superior, and posterior approaches, but the inferior axillary approach is rarely considered in the literature. However, this technique allows the direct visualization of relevant anatomic structures. The aim of this pictorial essay is, first, to technically describe this approach and the normal musculoskeletal sonographic anatomy of the region and, second, to present the sonographic findings of shoulder disorders that may be helpfully explored this technique.
Updated Retrospective Single‐Center Comparative Analysis of Peripheral Nerve Block Complications Using Landmark Peripheral Nerve Stimulation Versus Ultrasound Guidance as a Primary Means of Nerve Localization
Authors: Melnyk Vladyslav , Ibinson James W. , Kentor Michael L. , Orebaugh Steven L.
Published: March 2018

Objectives

The purpose of this study was to perform an updated analysis of complications associated with upper and lower extremity peripheral nerve blocks (PNBs) performed with ultrasound (US) guidance versus the landmark approach.

Methods

We conducted a single‐center retrospective cohort analysis to compare the incidence of PNB complications between the techniques. The primary outcome was local anesthetic systemic toxicity (LAST), whereas the secondary outcomes included short‐ and long‐term nerve injuries. The current query included cases performed between 2012 and 2015. A combined analysis included data extending to 2006. The Statistical examination relied on the χ2 test.

Results

During this 4‐year period, we performed 7789 US‐guided and 498 landmark‐guided blocks with no statistically significant difference in the incidence of nerve injury or LAST between the groups. Our 10‐year analysis, however, revealed a significant increase (P < .01) in the rate of LAST with the landmark technique: 7 of 5932 versus 0 of 16,858 cases. The combined data also revealed a significant increase (P < .01) in short‐term injuries associated with the landmark approach (30 of 5932 versus 33 of 16,858) but no significant difference in the incidence of long‐term injuries.

Conclusions

Our analysis supports a conclusion that the use of US guidance during PNBs leads to a significant reduction in the incidence of LAST, adding to growing evidence from similar investigations. The impact of US on the incidence of nerve injuries remains unclear, considering that the nature of transient deficits is thought to be multifactorial, and the frequency of lasting injuries did not differ significantly in this study.
Effect of Emergency Physician–Performed Point‐of‐Care Ultrasound and Radiology Department–Performed Ultrasound Examinations on the Emergency Department Length of Stay Among Pregnant Women at Less Than 20 Weeks' Gestation
Authors: Morgan Brian B. , Kao Amanda , Trent Stacy A. , Hurst Nicole , Oliveira Lauren , Austin Andrea L. , Kendall John L.
Published: March 2018

Objectives

We sought to confirm retrospective studies that measured an approximately 20% reduction in emergency department (ED) length of stay (LOS) in early‐gestation pregnant women who receive emergency physician–performed point‐of‐care ultrasound (US) examinations rather than radiology department–performed US examinations for evaluation of intrauterine pregnancy (IUP).

Methods

A randomized controlled clinical trial was performed at an urban academic safety net hospital and 2 Naval medical centers in the United States. The allocation was concealed before enrollment. Clinically stable adult pregnant women at less than 20 weeks' gestation who presented to the ED with abdominal pain or vaginal bleeding were randomized to receive a point‐of‐care or radiology US to assess for IUP. The primary outcome measure was the ED LOS.

Results

A total of 224 patients (point‐of‐care US, n = 118; radiology US, n = 106) were included for the analysis. The ED LOS was 20 minutes shorter in the point‐of‐care US arm (95% confidence interval [CI], –54 to 7 minutes). Adjusting for variability due to the location, the ED LOS was calculated to be 31 minutes shorter (95% CI, –64 to 1 minute) than for patients in the radiology US arm. Excluding patients in the point‐of‐care US arm who crossed over to radiology US after an inconclusive point‐of‐care US examination, the ED LOS was 75 minutes shorter than in the radiology US arm (95% CI, –97 to –53 minutes).

Conclusions

Early‐gestation pregnant ED patients requiring pelvic US were discharged earlier when point‐of‐care US was used rather than radiology US; however, this trial did not achieve our target of 30 minutes. Nevertheless, our data support the routine use of ED point‐of‐care US for IUP, saving the most time if a conclusive IUP is identified.
Determination of Normal Skin Elasticity by Using Real‐time Shear Wave Elastography
Authors: Yang Yujia , Wang Liyun , Yan Feng , Xiang Xi , Tang Yuanjiao , Zhang Lingyan , Liu Jibin , Qiu Li
Published: March 2018

Objectives

To define the reference ranges of normal skin elasticity measurements associated with shear wave elastography (SWE) in healthy volunteers and analyze the factors that may affect SWE.

Methods

Mean skin thickness and elastic modulus values from 90 healthy volunteers were evaluated with B‐mode ultrasonography and SWE in the right fingers and forearms, anterior chest, and abdominal walls. Reference ranges of normal skin elasticity were calculated by using lower and upper limits at the 2.5th and 97.5th percentiles. To investigate the effects of potential factors (site, sex, age, body mass index, and skin thickness) on skin elasticity measurements, a 1‐way analysis of variance, the Student t test, and the Pearson correlation test were performed.

Results

Skin elasticity was significantly different at different sites (P < .05). Mean elastic modulus values were 30.3 kPa for the finger, 14.8 kPa for the forearm, 17.8 kPa for the chest wall, and 9.5 kPa for the abdominal wall, and reference ranges of normal skin elasticity were 12.1 to 48.4kPa for the finger, 3.5 to 26.0 kPa for the forearm, 6.6 to 28.9 kPa for the chest wall, and 3.5 to 15.5 kPa for the abdominal wall. Our study revealed that men had higher skin elasticity measurements than women (P < .05), and they were more elevated in participants aged 20 to 50 years than in the other groups at the finger (P < .05). The body mass index and skin thickness had a negligible impact on skin elasticity measurements (P > .05).

Conclusions

This study revealed that the site, sex, and age should be taken into account when determining the reference ranges of normal skin elasticity by skin elasticity measurements.
Accuracy of Medical Students in Detecting Pleural Effusion Using Lung Ultrasound as an Adjunct to the Physical Examination
Authors: Steinmetz Peter , Oleskevich Sharon , Dyachenko Alina , McCusker Jane , Lewis John
Published: March 2018

Objectives

This study compared the accuracy of medical students in identifying pleural effusion in hospitalized patients using the physical examination versus lung ultrasound (US).

Methods

Fourth‐year medical students (n = 14) received 20 hours of general practical US training (including 2 hours of specialized lung US training) plus theoretical and video documentation. The students used the physical examination alone versus the physical examination plus lung US to document the presence or absence of pleural effusion in the right and left hemithoraces of hospitalized patients (n = 11 patients; 22 hemithoraces examined 544 times in total). The reference standard for identification of pleural effusion was a lung US examination by 2 expert point‐of‐care sonographers.

Results

The odds of correctly identifying the presence versus absence of pleural effusion was 5 times greater with lung US as an adjunct to the physical examination compared to the physical examination alone (odds ratio [OR], 5.1 from multivariate logistic regression; 95% confidence interval, 3.3–8.0). The addition of lung US to the physical examination resulted in an increase in sensitivity from 48% to 90%, in specificity from 73% to 86%, and in accuracy from 60% to 88%. The benefits of using US were greater when pleural effusion was present versus absent (OR, 10.8 versus 2.4) and when examining older versus younger patients (OR, 10.2 versus 2.8).

Conclusions

These results demonstrate that medical students' ability to detect the presence or absence of pleural effusion is superior when using lung US as an adjunct to the physical examination than when using the physical examination alone.
Comparison of the Diagnostic Efficacy of Ultrasound‐Guided Core Needle Biopsy With 18‐ Versus 20‐Gauge Needles for Thyroid Nodules
Authors: Ahn Hye Shin , Seo Mirinae , Ha Su Min , Kim Hee Sung
Published: March 2018

Objectives

To compare the diagnostic efficacy, complication rate, and core needle biopsy (CNB) specimen yield in 18‐ versus 20‐gauge ultrasound (US)‐guided CNB for diagnosis of thyroid nodules.

Methods

We included 81 consecutive thyroid nodules with US‐guided biopsy by a 20‐gauge core needle and 86 consecutive thyroid nodules with US‐guided biopsy by an 18‐gauge core needle during 2 years. The rate of inconclusive results, including nondiagnostic or atypia/follicular lesion of undetermined significance, was compared. The diagnostic performance for malignancy was assessed in nodules with a final diagnosis. The complication rate and CNB specimen yield were also compared.

Results

Eighteen‐gauge CNB showed a lower rate of nondiagnostic results (1.2% versus 8.6%; P = .024) than 20‐gauge CNB; however, the rates of atypia/follicular lesion of undetermined significance and inconclusive results were not significantly different between the groups (P > .05). In addition, 18‐gauge CNB showed higher sensitivity (75.0% versus 66.7%), a higher negative predictive value (83.9% versus 75.9%), and higher accuracy (78.3% versus 74.4%) for detecting malignancy than 20‐gauge CNB, although the results did not achieve statistical significance. No major complications occurred in either of the CNB groups. The 18‐gauge needle group had significantly fewer CNBs and larger specimen diameters (P < .001).

Conclusions

Core needle biopsy with an 18‐gauge needle could be more effective for the diagnosis of thyroid nodules than CNB with a 20‐gauge needle.
Influence of hunting on movements of moose near roads
Authors: Neumann Wiebke , Ericsson Göran
Published: March 2018

Vehicle collisions with large wildlife provide a serious risk of severe personal injuries. In some countries, there is a common belief that hunting increases this risk because it leads to more active animals and increases roads crossings. We analyzed movements of moose (Alces alces) and frequency of moose road crossings during fall to test if moose altered their behavior during hunting periods compared to other times. We analyzed global positioning system (GPS) data from 172 free‐ranging adult moose (140 females, 32 males) between the end of August and the middle of October 2004–2013, in 7 different areas along Sweden's latitudinal gradient of 57°N–67°N. Female moose either decreased or did not change their movement rates as fall proceeded, and they did not cross roads more in any weeks of the hunting season. Male moose became more active between mid‐September and the beginning of October, which corresponds to the time before the hunting period in southern Sweden and the temporary hunting closure in northern Sweden. There was no overall change in moose movements in relation to hunting activity during fall regardless of region or sex. We found that number of road crossings correlated positively with the rutting period in male moose. Thus, the riskier periods for traffic during fall during the hunting period, based on moose movement, coincided with the rutting activity. We suggest that mitigation actions to reduce moose‐vehicle collisions should make drivers more aware of changes in movement behavior in moose during the rutting season, particularly in southern Sweden. © 2018 The Wildlife Society.
Habitat suitability modeling in different sperm whale social groups
Authors: Pace Daniela Silvia , Arcangeli Antonella , Mussi Barbara , Vivaldi Carlotta , Ledon Cristina , Lagorio Serena , Giacomini Giancarlo , Pavan Gianni , Ardizzone Giandomenico
Published: March 2018

The identification of significant habitats for highly mobile marine vertebrates is essential for their conservation. Evidence is often difficult to obtain for deep‐diving species such as sperm whales (Physeter macrocephalus), where standard visual survey methods are not sufficient to detect the species. Sperm whales rely on sound for most of their activities, so acoustics is a crucial tool to locate them in the environment and collect information about their daily life. We used a maximum entropy (MaxEnt) modeling approach to predict potential habitats for sperm whales during 2007–2015 in an area of the Mediterranean Sea (characterized by submarine canyon systems) where sperm whale singletons, social units of females and calves, and clusters with immature males, were regularly encountered in sympatry. Models to test species’ distribution and the potential differences between groups of varying composition and life stages were based on 3 independent variables (depth, slope, and Euclidean distance from the nearest coast) and a combination of presence‐only visual and acoustic data from boat‐based surveys. One variable (depth) was the strongest predictor in all encounters (pooled data) and clusters, whereas distance from coast and slope best predicted encounters with singletons and social units, respectively. The model predicted suitable locations in areas that were well‐known sperm whale habitat and in new regions of previously overlooked habitat, which possibly represent key areas for this endangered species in the Mediterranean. This study highlights that consideration should be taken regarding type of social aggregation when using modeling techniques for generating suitable habitat maps for conservation purposes. © 2018 The Wildlife Society.