bluuebunny/crossref_metadata_2025 huggingface dataset:
College Students’ Well–Being: Use of Counseling Services
Authors: Huenergarde Morgan
Published: May 2019

A significant number of college students experience varying levels of stress, anxiety, homesickness, and depression which may negatively impact their academic performance or personal functioning. However, many college students do not seek professional help from campus counselors. Recent research supports the effectiveness of counseling centers in reducing the effect of stress, anxiety, homesickness, and depression on the students’ well-being. The purpose to the current study was to analyze students’ reports on their levels of stress, anxiety, homesickness, and depression, grouping them based on previous counseling participation. It was hypothesized that those who had gone to counseling or were currently attending counseling would report better overall improvement than those students who had never attended counseling. The following study included college students at a Southeastern university who have attended counseling or were currently attending counseling through the services provided by the University, or from any outside service. A group of students who had never attended counseling previously also participated. The research assessed varying levels of mood and academic performance and any differences between the groups. To gather a broader scope of knowledge, the study investigated demographic information and potential hindrances to treatment. It also focused on any barriers that would impact the likelihood of counseling attendance, and the manner in which students learned about the services offered. It was found that those students who attended six or more counseling sessions reported more positive perceived change in their levels of depression, anxiety, and stress than did students who attended five or fewer counseling sessions. Most students reported that they would not attend counseling due to not having enough time and suggested online or weekend sessions. Finally, students stated that they predominantly learned about services from advertisement.
KEYWORDS: Counseling; College Students; Depression; Homesickness; Anxiety; Stress; Mood; Academic Performance
ZYGMUNT BAUMAN METİNLERİNDE SOSYAL MEDYA VE ÖZGÜRLÜK OLGUSU
Authors: FERİDUNOĞLU İsmail Cem
Published: May 2019

İnsanın
yeryüzündeki birkaç milyon yıla dayanan serüveni, günümüzden on bin yıl kadar
önce tarımın başlamasına dek sakin çizgisini korumuş; ancak yeryüzü, daha sonra
hareketli gelişmelere sahne olmuştur. Uzun sakinlik döneminden sonra yaşanan
hızlı gelişmeler; özellikle, sanayi devriminin ardından artmış ve insanlar daha
önceleri görülmemiş boyutlarda değişen yaşam tarzlarıyla karşı karşıya kalmış
ve yaklaşık 50 yıl kadar önce üçüncü dalga olarak, servetlerini bilgiden
ürettikleri Bilgi Çağını başlatmışlardır. Bu gelişmelere paralel olarak,
internetin hızlı ve kapsamlı bir şekilde etkisini arttırması, onu bir
teknolojik yenilik olmanın ötesine taşıdı. Günümüzde internet; kültür, kimlik,
siyaset ve ekonomi, alanı olarak tartışılmaktadır Bauman, iletişim ve
bilgisayar teknolojisindeki hızlı gelişimlerin, insanların yaşamlarındaki
etkilerini alan çalışmalara yoğunlaşmıştır. Özgürlüğü toplumsal bir ilişki
olarak ele alan Bauman, insanların kuruluş amacı iletişim olan sosyal medyayı,
yalnız kendilerini görecekleri bir ayna olarak kullanıp, özgürlüklerini kendi
kendilerine kısıtladıklarını ifade etmektedir. Bu bağlamda çalışmada Bauman
metinlerinde sosyal medya ve özgürlük konuları ile ilgili içerik analizi
yapılmıştır.
Optical Flow Estimation with Occlusion Detection
Authors: Wang Song , Wang Zengfu
Published: May 2019

The dense optical flow estimation under occlusion is a challenging task. Occlusion may result in ambiguity in optical flow estimation, while accurate occlusion detection can reduce the error. In this paper, we propose a robust optical flow estimation algorithm with reliable occlusion detection. Firstly, the occlusion areas in successive video frames are detected by integrating various information from multiple sources including feature matching, motion edges, warped images and occlusion consistency. Then optimization function with occlusion coefficient and selective region smoothing are used to obtain the optical flow estimation of the non-occlusion areas and occlusion areas respectively. Experimental results show that the algorithm proposed in this paper is an effective algorithm for dense optical flow estimation.
Absence of Effects of Herbicides Use on Yam Rots: A Case Study in Wulensi, Ghana
Authors: Wumbei Abukari , Bawa Judith Kania Asibi , Akudugu Mamudu Abunga , Spanoghe Pieter
Published: May 2019

Yam farmers in Ghana have, over the years, used herbicides for weed control, particularly glyphosate. Although this has been helpful to them, there are complaints and concerns, among the yam farmers and a section of the public, that the yam tuber rots easily under the use of herbicides. This study, therefore, was set up at the field level to investigate the possibility of herbicides use causing yam rot. Two yam varieties, “laribako” and “olodo”, were grown under the conditions of chemical weed control (use of glyphosate) and manual weed control in three replicate sites in Wulensi in the Nanumba traditional area of northern Ghana. The study revealed that there was no difference in rots between herbicide treated yams and manually weeded yams, but that there was a difference in rots between “laribako” and “olodo” yam varieties. The results also showed that there was no difference in yield between herbicide treated yams and manually weeded yams. Based on the findings, it can be concluded that, there was no difference in yam rot and yield between herbicides treated and manually weeded yams, but “laribako” was more susceptible to rot than “olodo”.
Correlation between the Lunar Phase and Tail-Lifting Behavior of Lizards (Pogona vitticeps) Exposed to an Extremely Low-Frequency Electromagnetic Field
Authors: Nishimura Tsutomu , Tada Harue , Fukushima Masanori
Published: May 2019

We previously showed that the agamid lizard Pogona vitticeps responded to an extremely low-frequency electromagnetic field (ELF-EMF; frequency: 6 and 8 Hz; peak magnetic field: 2.6 µT; peak electric field: 10 V/m) with tail-lifting behavior. In addition, the tail-lifting response to ELF-EMF disappeared when the parietal eyes of the lizards were covered by small round aluminum caps. This result suggests that the parietal eye contributes to light-dependent magnetoreception. In the present study, we set up an ELF-EMF group to evaluate the long-term effect of the ELF-EMF on lizards’ behavior and examine our hypothesis that exposure to ELF-EMFs increases the magnetic field sensitivity in lizards. We therefore include the lunar phase (full moon/new moon) and K index as environmental factors related to the geomagnetic field in the analysis. The number of tail lifts per individual per day was the response variable while calendar month, daily mean temperature, daily mean humidity, daily mean atmospheric pressure, full moon, new moon, and K index were the explanatory variables. We analyzed an ELF-EMF group and a control group separately. In a multiple linear regression analysis, the independent determinants associated with the number of tail lifts were the full moon, the temperature, February, March, April, and May in the ELF-EMF group and March, April, May, and June in the control group. The P. vitticeps in the ELF-EMF group responded to the full moon whereas those in the control group did not. In addition, in the ELF-EMF group, the number of tail lifts was higher on days when the K index was higher (P = 0.07) in the first period whereas there was no such tendency in either period in the control group. There is the possibility that the exposure to ELF-EMFs may increase magnetic-field sensitivity in lizards.
All-Optical Modulation and Ultrafast Switching in MWIR with Sub-Wavelength Structured Silicon
Authors: Wu Rihan , Collins Jack , Chekulaev Dimitri , Kaplan Andrey
Published: May 2019

We investigated and optimised the performance of the all-optical reflective modulation of the Mid-Wave Infrared (MWIR) signal by means of the optically-pumped sub-wavelength-structured optical membranes made of silicon. The membranes were optically pumped by a 60-femtosecond, 800-nm laser, while another laser operating in the MWIR ranging between 4 and 6 μ m was used to probe the optical response and modulation. We were able to achieve the conditions providing the modulation depth of 80% using the pump fluence of 3.8 mJ/cm 2 . To get a better insight into the performance and the modulation mechanism, we developed an optical model based on a combination of the Wentzel–Kramers–Brillouin approximation, Drude and Maxwell–Garnett theories. The model allowed us to estimate the values of the dielectric function, carrier concentration and scattering rate of the optically-excited membrane in the MWIR range. Using the model, we optimised the performance and found the conditions at which the reflective modulation can be operated with the ultrafast response of 0.55 ps and modulation contrast of 30%.
Beam Propagation Factor of a Cosh-Airy Beam
Authors: Zhou Yimin , Xu Yiqing , Zhou Guoquan
Published: May 2019

Based on the second-order moments, the analytical expression of the beam propagation factor of a cosh-Airy beam has been derived. The beam propagation factor was determined by the decay factor and the cosh parameter. Because the beam propagation factors in the x- and y-directions of the cosh-Airy beam have the same form, only the beam propagation factor in the x- direction was selected as the object of numerical calculation and analysis. The effects of the decay factor and the cosh parameter on the beam propagation factor were investigated. When the decay factor was greater than 1, the beam propagation factor first increased and then decreased with the increase of the cosh parameter, and finally, tended to a minimum value. Under the condition that the decay factor was less than 1, the beam propagation factor always increased with the increase of the cosh parameter. As the decay factor increased, the beam propagation factor decreased and tended to a minimum value. Finally, the effects of the decay factor and the cosh parameter on the squares of the beam waist and the divergence were analyzed in more detail.
Prevalence and Predictors of Osteoporosis Among the Chinese Population in Klang Valley, Malaysia
Authors: Subramaniam Shaanthana , Chan Chin-Yi , Soelaiman Ima-Nirwana , Mohamed Norazlina , Muhammad Norliza , Ahmad Fairus , Abd Manaf Mohd Rizal , Ng Pei-Yuen , Jamil Nor Aini , Chin Kok-Yong
Published: May 2019

The prevalence of osteoporosis is forecasted to escalate in Malaysia with an increasing elderly population. This study aimed to analyze the prevalence and the risk factors of osteoporosis among middle-aged and elderly Chinese Malaysians. Three hundred sixty seven Malaysian Chinese aged ≥40 years in Klang Valley, Malaysia, were recruited. All subjects completed a structured questionnaire comprised of demographic details, medical history, diet, and lifestyle practices. Body anthropometry and bone mineral density measurements were also performed. The relationship between bone health status and risk factors was determined using multivariate logistic regression. Fifteen-point-three percent of the overall study population and 32.6% of those aged ≥71 years had osteoporosis. The prevalence of osteoporosis among women (18.9%) was higher than men (11.5%). The significant predictors of osteoporosis were age, body weight, and low monthly income. Lean mass, low education level, and being underweight predicted osteoporosis in women. Lean mass was the only significant predictor of osteoporosis in men. Overall, 15.3% of the Malaysian Chinese aged ≥40 years from Klang Valley, Malaysia, had osteoporosis. Osteoporosis was associated positively with increased age and low monthly income and negatively with body weight. Therefore, osteoporosis preventive strategies targeting Chinese elderly from a low socioeconomic background is necessary.
Computational Intelligence in Photovoltaic Systems
Authors: Leva Sonia , Ogliari Emanuele
Published: May 2019

Photovoltaics, among renewable energy sources (RES), has become more popular [...]
Automated Classification of the Tympanic Membrane Using a Convolutional Neural Network
Authors: Lee Je Yeon , Choi Seung-Ho , Chung Jong Woo
Published: May 2019

Precise evaluation of the tympanic membrane (TM) is required for accurate diagnosis of middle ear diseases. However, making an accurate assessment is sometimes difficult. Artificial intelligence is often employed for image processing, especially for performing high level analysis such as image classification, segmentation and matching. In particular, convolutional neural networks (CNNs) are increasingly used in medical image recognition. This study demonstrates the usefulness and reliability of CNNs in recognizing the side and perforation of TMs in medical images. CNN was constructed with typically six layers. After random assignment of the available images to the training, validation and test sets, training was performed. The accuracy of the CNN model was consequently evaluated using a new dataset. A class activation map (CAM) was used to evaluate feature extraction. The CNN model accuracy of detecting the TM side in the test dataset was 97.9%, whereas that of detecting the presence of perforation was 91.0%. The side of the TM and the presence of a perforation affect the activation sites. The results show that CNNs can be a useful tool for classifying TM lesions and identifying TM sides. Further research is required to consider real-time analysis and to improve classification accuracy.
Response of QIT-MS to Noble Gas Isotopic Ratios in a Simulated Venus Flyby
Authors: Nikolić Dragan , Madzunkov Stojan M. , Darrach Murray R.
Published: May 2019

The primary objective of the present study is to investigate the science return of future Venus atmosphere probe mission concepts using the Quadrupole Ion Trap (QIT) Mass Spectrometer (MS) Instrument (QIT-MS-I). We demonstrate the use of Monte-Carlo simulations in determining the optimal ion trapping conditions and focus the analysis on retrieving isotope ratios of noble gases in the model sample of the Venus atmosphere. Sampling takes place at a constant velocity of ~10 km/s between 112–110 km altitude and involves the use of getter pumps to remove all chemically-active species, retaining inert noble gases. The enriched sample is leaked into passively pumped vacuum chamber where it is analyzed by the QIT-MS sensor (QIT-MS-S) for 40 minutes. The simulated mass spectrum, as recorded by the QIT-MS-S, is deconvoluted using random walk algorithm to reveal relative abundances of noble gas isotopes. The required precision and accuracy of the deconvolution method is benchmarked against the a priori known model composition of the atmospheric sample.
Combinatorial Optimization for WRF Physical Parameterization Schemes: A Case Study of Three-Day Typhoon Simulations over the Northwest Pacific Ocean
Authors: Di Zhenhua , Gong Wei , Gan Yanjun , Shen Chenwei , Duan Qingyun
Published: May 2019

Quantifying a set of suitable physics parameterization schemes for the Weather Research and Forecasting (WRF) model is essential for obtaining highly accurate typhoon forecasts. In this study, a systematic Tukey-based combinatorial optimization method was proposed to determine the optimal physics schemes of the WRF model for 15 typhoon simulations over the Northwest Pacific Ocean, covering all available schemes of microphysics (MP), cumulus (CU), and planetary boundary layer (PBL) physical processes. Results showed that 284 scheme combination searches were sufficient to find the optimal scheme combinations for simulations of track (km), central sea level pressure (CSLP, hPa), and 10 m maximum surface wind (10-m wind, m s−1), compared with the 700 sets of full combinations (i.e., 10 MP × 7 CU × 10 PBL). The decrease in the typhoon simulation error (i.e., root mean square error between simulation and observations) with this optimal scheme combination was 34%, 33.92%, and 25.67% for the track, CSLP, and 10-m wind, respectively. Overall, the results demonstrated that the optimal scheme combination yields reasonable results, and the Tukey-based optimization method is very effective and efficient in terms of computational resources.
Changes in the Relationship between Particulate Matter and Surface Temperature in Seoul from 2002–2017
Authors: Kim Minjoong J.
Published: May 2019

This study focuses on the changes over time in the relationship between surface temperature and particulate matter (PM) concentration over Seoul using long-term observational data. Correlation coefficients between the daily mean PM10 concentration and surface temperature were calculated to investigate the relationship between the two. The PM10 and temperature displayed a strong positive correlation, suggesting the increase in PM was driven by large-scale synoptic patterns accompanying such high temperatures. It was found that the correlation coefficient in 2002–2009 was significantly higher than that of 2010–2017, indicating that the relationship between PM10 concentration and temperature has weakened over time in recent decades. Correlation coefficients between daily averaged temperature and the PM10 of each year were calculated to account for the decreased correlation in the most recent decade. We found that the correlation coefficients between surface temperature and PM of each year exhibited a clear negative correlation with the longitudinal position of the Siberian High, suggesting that the position of the Siberian High might affect the strength of the relationship between PM concentration and temperature over Seoul. We also found that the eastward shift of the Siberian High reduces the standard deviation of pressure over Seoul, indicating reduction of synoptic perturbation. These results imply that the eastward shift of the Siberian High in recent decades might weaken the relationship between the PM and surface temperature over Seoul. This study suggests that the relationship between PM and meteorological variables is changing over time through changes in large climate variability.
Role of the South Asian High in the Onset Process of the Asian Summer Monsoon during Spring-to-Summer Transition
Authors: Wei Wei , Wu Yuting , Yang Song , Zhou Wen
Published: May 2019

The evolution of the South Asian high (SAH) and its role in the onset process of the Asian summer monsoon (ASM) during the spring-to-summer transition are investigated by using the NCEP-DOE reanalysis II dataset, with a focus on climatology and interannual time scales. Our results show four sudden changes of the SAH in its Northwestward evolution from the Western Pacific to the South China Sea (SCS), the Indochina Peninsula and the South Asian plateaus, coincide with the ASM onset over the Bay of Bengal, the SCS, and the Indian summer monsoon region. The physical process for the mutual promotion between the SAH and ASM rainfall is revealed. Accompanying the SAH evolution, the upper-level Easterly wind along the Southern flank and the upper-level divergence associated with the SAH shift Northwestward accordingly. The upper-level Easterly wind coordinates with the lower-level Southwesterly wind, and forms the summer circulation structure in the ASM regions gradually. Besides, the upper-level divergence associated with the SAH enhances ascending motion in ASM regions and increases the monsoon rainfall accordingly. Subsequently, the latent heat associated with the monsoon rainfall in the monsoon onset region excites an anticyclone to its Northwest in the upper level, which keeps strengthening the SAH and moving it Northwestward. This mutual promotion between the SAH and ASM rainfall can be affected by the sea surface temperatures (SSTs) in the Western Pacific and tropical Indian Ocean in the previous month. Colder (warmer) SSTs over the Western Pacific and inactive (active) convection over the Southern Philippines suppress (favor) the Northwestward development of the SAH in late April. In addition, the warmer (colder) SSTs in the tropical Indian Ocean excites anomalous anticyclone (cyclone) in the upper level near the equator, which keeps the SAH in the lower latitudes (promotes the SAH to the North), and delays (advances) the mutual promotion between the SAH and ASM rainfall. As a result, the entire ASM onset process is later (earlier) than normal.
Parameter Modulation of Madden-Julian Oscillation Behaviors in BCC_CSM1.2: The Key Role of Moisture-Shallow Convection Feedback
Authors: Huang Kai , Ren Hong-Li , Liu Xiangwen , Ren Pengfei , Wei Yuntao , Mu Mu
Published: May 2019

To reveal key parameter-related physical mechanisms in simulating Madden-Julian Oscillation (MJO), seven physical parameters in the convection and cloud parameterization schemes of Beijing Climate Center Climate System Model (BCC_CSM1.2) are perturbed with Latin hypercube sampling method. A new strategy is proposed to select runs with good and poor MJO simulations among 85 generated ones. Outputs and parameter values from good and poor simulations are composited separately for comparison. Among the seven chosen parameters, a decreased value of precipitation efficiency for shallow convection, higher values of relative humidity threshold for low stable clouds and evaporation efficiency for deep convective precipitation are crucial to simulate a better MJO. Changes of the three parameters act together to suppress heavy precipitation and increase the frequency of light rainfall over the Indo-Pacific region, supplying more moisture in low and middle troposphere. As a result of a wetter lower troposphere ahead of the MJO main convection, the low-level moisture preconditioning along with the leading shallow convection tends to be enhanced, favorable for MJO’s further development and eastward propagation. The MJO’s further propagation across the Maritime Continent (MC) in good simulations is accompanied with more land precipitation dominated by shallow convection. Therefore, the above-mentioned three parameters are found to be crucial parameters out of the seven ones for MJO simulation, providing an inspiration for better MJO simulation and prediction with this model. This work is valuable as it highlights the key role of moisture-shallow convection feedback in the MJO dynamics.
Development of Artificial Neural Network Models to Assess Beer Acceptability Based on Sensory Properties Using a Robotic Pourer: A Comparative Model Approach to Achieve an Artificial Intelligence System
Authors: Gonzalez Viejo Claudia , Torrico Damir D. , Dunshea Frank R. , Fuentes Sigfredo
Published: May 2019

Artificial neural networks (ANN) have become popular for optimization and prediction of parameters in foods, beverages, agriculture and medicine. For brewing, they have been explored to develop rapid methods to assess product quality and acceptability. Different beers (N = 17) were analyzed in triplicates using a robotic pourer, RoboBEER (University of Melbourne, Melbourne, Australia), to assess 15 color and foam-related parameters using computer-vision. Those samples were tested using sensory analysis for acceptability of carbonation mouthfeel, bitterness, flavor and overall liking with 30 consumers using a 9-point hedonic scale. ANN models were developed using 17 different training algorithms with 15 color and foam-related parameters as inputs and liking of four descriptors obtained from consumers as targets. Each algorithm was tested using five, seven and ten neurons and compared to select the best model based on correlation coefficients, slope and performance (mean squared error (MSE). Bayesian Regularization algorithm with seven neurons presented the best correlation (R = 0.98) and highest performance (MSE = 0.03) with no overfitting. These models may be used as a cost-effective method for fast-screening of beers during processing to assess acceptability more efficiently. The use of RoboBEER, computer-vision algorithms and ANN will allow the implementation of an artificial intelligence system for the brewing industry to assess its effectiveness.
Integrated Transcriptomic, Proteomic, and Metabolomics Analysis Reveals Peel Ripening of Harvested Banana under Natural Condition
Authors: Yun Ze , Li Taotao , Gao Huijun , Zhu Hong , Gupta Vijai Kumar , Jiang Yueming , Duan Xuewu
Published: May 2019

Harvested banana ripening is a complex physiological and biochemical process, and there are existing differences in the regulation of ripening between the pulp and peel. However, the underlying molecular mechanisms governing peel ripening are still not well understood. In this study, we performed a combination of transcriptomic, proteomic, and metabolomics analysis on peel during banana fruit ripening. It was found that 5784 genes, 94 proteins, and 133 metabolites were differentially expressed or accumulated in peel during banana ripening. Those genes and proteins were linked to ripening-related processes, including transcriptional regulation, hormone signaling, cell wall modification, aroma synthesis, protein modification, and energy metabolism. The differentially expressed transcriptional factors were mainly ethylene response factor (ERF) and basic helix-loop-helix (bHLH) family members. Moreover, a great number of auxin signaling-related genes were up-regulated, and exogenous 3-indoleacetic acid (IAA) treatment accelerated banana fruit ripening and up-regulated the expression of many ripening-related genes, suggesting that auxin participates in the regulation of banana peel ripening. In addition, xyloglucan endotransglucosylase/hydrolase (XTH) family members play an important role in peel softening. Both heat shock proteins (Hsps) mediated-protein modification, and ubiqutin-protesome system-mediated protein degradation was involved in peel ripening. Furthermore, anaerobic respiration might predominate in energy metabolism in peel during banana ripening. Taken together, our study highlights a better understanding of the mechanism underlying banana peel ripening and provides a new clue for further dissection of specific gene functions.
Current Status of In Vitro Models and Assays for Susceptibility Testing for Wound Biofilm Infections
Authors: Bahamondez-Canas Tania F. , Heersema Lara A. , Smyth Hugh D. C.
Published: May 2019

Biofilm infections have gained recognition as an important therapeutic challenge in the last several decades due to their relationship with the chronicity of infectious diseases. Studies of novel therapeutic treatments targeting infections require the development and use of models to mimic the formation and characteristics of biofilms within host tissues. Due to the diversity of reported in vitro models and lack of consensus, this review aims to provide a summary of in vitro models currently used in research. In particular, we review the various reported in vitro models of Pseudomonas aeruginosa biofilms due to its high clinical impact in chronic wounds and in other chronic infections. We assess advances in in vitro models that incorporate relevant multispecies biofilms found in infected wounds, such as P. aeruginosa with Staphylococcus aureus, and additional elements such as mammalian cells, simulating fluids, and tissue explants in an attempt to better represent the physiological conditions found at an infection site. It is hoped this review will aid researchers in the field to make appropriate choices in their proposed studies with regards to in vitro models and methods.
Study on Durability Properties of Coconut Shell Concrete with Coconut Fiber
Authors: Sekar Anandh , Kandasamy Gunasekaran
Published: May 2019

Coconut fiber was used in coconut shell concrete (CSC) and its durability properties were studied. The properties include: water absorption, volume of permeable pore voids, rapid chloride penetration test, sorptivity and resistance at elevated temperature. For comparison purpose, these properties were also studied on conventional concrete (CC) with coconut fibers. Three different curing conditions viz. full water immersion, site curing and air-dry conditions were employed except for temperature resistance study in which only full water immersion was used. Test results show that the durability properties were better in full water immersion condition in case of CC mixes and in site curing condition in case of CSC mixes. Temperature resistance tests gave a minimum guarantee of both CC and CSC mixes without and with coconut fibers for 2 h resistance and hence they were deemed safe for construction.
Molecular Alterations in Dog Pheochromocytomas and Paragangliomas
Authors: Korpershoek Esther , Dieduksman Daphne A. E. R. , Grinwis Guy C. M. , Day Michael J. , Reusch Claudia E. , Hilbe Monika , Fracassi Federico , Krol Niels M. G. , Uitterlinden André G. , de Klein Annelies , Eussen Bert , Stoop Hans , de Krijger Ronald R. , Galac Sara , Dinjens Winand N. M.
Published: May 2019

Recently, genetic alterations in the genes encoding succinate dehydrogenase subunit B and D (SDHB and SDHD) were identified in pet dogs that presented with spontaneously arising pheochromocytomas (PCC) and paragangliomas (PGL; together PPGL), suggesting dogs might be an interesting comparative model for the study of human PPGL. To study whether canine PPGL resembled human PPGL, we investigated a series of 50 canine PPGLs by immunohistochemistry to determine the expression of synaptophysin (SYP), tyrosine hydroxylase (TH) and succinate dehydrogenase subunit A (SDHA) and B (SDHB). In parallel, 25 canine PPGLs were screened for mutations in SDHB and SDHD by Sanger sequencing. To detect large chromosomal alterations, single nucleotide polymorphism (SNP) arrays were performed for 11 PPGLs, including cases for which fresh frozen tissue was available. The immunohistochemical markers stained positive in the majority of canine PPGLs. Genetic screening of the canine tumors revealed the previously described variants in four cases; SDHB p.Arg38Gln (n = 1) and SDHD p.Lys122Arg (n = 3). Furthermore, the SNP arrays revealed large chromosomal alterations of which the loss of chromosome 5, partly homologous to human chromosome 1p and chromosome 11, was the most frequent finding (100% of the six cases with chromosomal alterations). In conclusion, canine and human PPGLs show similar genomic alterations, suggestive of common interspecies PPGL-related pathways.
Effect of Perioperative Lidocaine, Propofol and Steroids on Pulmonary Metastasis in a Murine Model of Breast Cancer Surgery
Authors: Freeman James , Crowley Peter D. , Foley Andrew G. , Gallagher Helen C. , Iwasaki Masae , Ma Daqing , Buggy Donal J.
Published: May 2019

Addressing the hypothesis that anaesthetic-analgesic technique during cancer surgery might influence recurrence or metastatic spread is a research priority. Propofol, which has anti-inflammatory properties in vitro, is clinically associated with reduced risk of cancer recurrence compared with sevoflurane anaesthesia in retrospective studies. Amide local anaesthetics, such as lidocaine, have cancer inhibiting effects in vitro. Steroids have anti-inflammatory and immunosuppressive effects and are associated with improved recovery after major non-cancer surgery. We compared the effects of propofol, lidocaine and methylprednisolone on postoperative metastasis in a murine model of breast cancer surgery under sevoflurane anaesthesia. 4T1 tumour cells were introduced into the mammary fat-pad of female BALB/c mice and the resulting tumour resected seven days later under general anaesthesia with sevoflurane. Mice (n = 72) were randomized to four treatment groups: Sevoflurane alone (control); Propofol group received 5 mg.kg−1; Lidocaine group received 1.5 mg.kg−1 followed by 2 mg.kg−1.h−1 infusion; Methylprednisolone group received 30 mg.kg−1 methylprednisolone. The primary outcome measure was pulmonary metastasis colony count, as assessed by in-vitro proliferation, two weeks post-operatively. This was achieved by treating the post-mortem lung tissue with collagenase IV, straining and culturing for 14 days prior to colony count. Compared with control, lidocaine and propofol each individually reduced pulmonary metastasis colonies; mean (SD) 846 (±581) vs. 88 (±52) vs. 34 (±44) respectively, (p = 0.0001 and p = 0.0001). Methylprednisolone increased lung metastasis, 2555 (±609) vs. 846 (±581), p = 0.0001. Post-operative hepatic metastatic disease and serum interleukin-6 and vascular endothelial growth factor levels were similar in all groups. In conclusion, in a murine model of breast cancer surgery during sevoflurane anaesthesia, propofol and lidocaine each decreased pulmonary metastasis, while methylprednisolone increased it.
Obesity and Hypogonadism—A Narrative Review Highlighting the Need for High-Quality Data in Adolescents
Authors: Mushannen Tasnim , Cortez Priscilla , Stanford Fatima Cody , Singhal Vibha
Published: May 2019

The prevalence of obesity continues to rise in adult and pediatric populations throughout the world. Obesity has a direct impact on all organ systems, including the reproductive system. This review summarizes current knowledge about the effects of obesity on the male reproductive system across age, highlighting the need for more data in children and adolescents. Male hypogonadism is commonly seen in patients with obesity and affects the onset, duration, and progression of puberty. Different pathophysiologic mechanisms include increased peripheral conversion of testosterone to estrone and increased inflammation due to increased fat, both of which lead to suppression of the hypothalamic-pituitary-gonadotropin (HPG) axis and delayed development of secondary sexual characteristics in adolescent males. Evaluation of the HPG axis in obesity includes a thorough history to exclude other causes of hypogonadism and syndromic associations. Evaluation should also include investigating the complications of low testosterone, including increased visceral fat, decreased bone density, cardiovascular disease risk, and impaired mood and cognition, among others. The mainstay of treatment is weight reduction, but medications such as testosterone and clomiphene citrate used in adults, remain scarcely used in adolescents. Male hypogonadism associated with obesity is common and providers who care for adolescents and young adults with obesity should be aware of its impact and management.
The 10-Year Return Levels of Maximum Wind Speeds under Frozen and Unfrozen Soil Forest Conditions in Finland
Authors: Laapas Mikko , Lehtonen Ilari , Venäläinen Ari , Peltola Heli M.
Published: May 2019

Reliable high spatial resolution information on the variation of extreme wind speeds under frozen and unfrozen soil conditions can enhance wind damage risk management in forestry. In this study, we aimed to produce spatially detailed estimates for the 10-year return level of maximum wind speeds for frozen (>20 cm frost depth) and unfrozen soil conditions for dense Norway spruce stands on clay or silt soil, Scots pine stands on sandy soil and Scots pine stands on drained peatland throughout Finland. For this purpose, the coarse resolution estimates of the 10-year return levels of maximum wind speeds based on 1979–2014 ERA-Interim reanalysis were downscaled to 20 m grid by using the wind multiplier approach, taking into account the effect of topography and surface roughness. The soil frost depth was estimated using a soil frost model. Results showed that due to a large variability in the timing of annual maximum wind speed, differences in the 10-year return levels of maximum wind speeds between the frozen and unfrozen soil seasons are generally rather small. Larger differences in this study are mostly found in peatlands, where soil frost seasons are notably shorter than in mineral soils. Also, the high resolution of wind multiplier downscaling and consideration of wind direction revealed some larger local scale differences around topographic features like hills and ridgelines.
Comparison of Two-Dimensional and Three-Dimensional Radiographs Using Clinically Relevant Parameters
Authors: Schmidt Julia C. , Gutekunst Claudia-Julie , Dagassan-Berndt Dorothea , Schmidlin Patrick R. , Walter Clemens
Published: May 2019

This work compared the assessment of clinically relevant parameters by two-dimensional, that is, full-mouth intraoral radiograph (I-O) and panoramic radiograph (OPT), and three-dimensional, that is, cone beam computed tomography (CBCT), imaging methods. Different radiographic images (CBCT, I-O and OPT) were available for a 53-year-old female patient with dental and periodontal problems. A total of 14 dental and periodontal parameters were assessed by two independent examiners and compared among the three radiographic imaging modalities. For 10 parameters (71%), the CBCT images were superior to both I-O and OPT images. In contrast, CBCT demonstrated an inferior performance compared to I-O and OPT in the assessment of caries and dental restorations. Compared to OPT, I-O provided more clinically relevant findings for 10 out of 14 parameters (71%). Agreement between I-O and OPT was found with respect to dehiscence, fenestration, the number of bone walls and the root canal cross-section. Differences between the radiographic images were more likely to be detected when maxillary teeth rather than mandibular teeth were assessed with regard to furcation involvement, root proximity and root fusion.
The Reflective Practicum in the Process of Becoming a Teacher: The Tutor’s Discursive Support
Authors: Cubero-Pérez Rosario , Cubero Mercedes , Bascón Miguel Jesús
Published: May 2019

Interest in reflective practices, within the broader framework of teachers’ professional knowledge, has been ongoing in educational research for the past few decades. The idea from which reflection itself stems is that of teachers’ agency in their own professional development. The initial positivist approach viewed the relationships between teachers’ theoretical knowledge and educational practice in terms of hierarchical reductionism. We analyze the relationships between different types of knowledge from a historical-cultural perspective, which requires locating them in the context of the cultural activities. Our aim is to analyze the discursive interactions, which take place during collaborative seminars, within a reflective practicum, and to identify how the university tutors support and foster reflection on practice. We use a multiple case design in which each case is a classroom unit made up of a tutor and his or her students. An analysis of the tutors’ discourse revealed an ongoing promotion of students’ active engagement through highly structured classroom participation, a strong focus on interpreting students’ personal experiences during teaching practice and significant interventions aimed at establishing links with academic knowledge. Results invite us to rethink the ways in which we can contribute to processes of reflection among trainee teachers.
Simple DC-Link Voltage Balancing Approach for Cascaded H-Bridge Rectifier with Asymmetric Parameters of Independent DC Loads
Authors: Zhu Jin , Wei Tongzhen , Ma Ming , Han Libo
Published: May 2019

CHB is a suitable type of topology for synchronous rectifier application which has two or more independent DC loads. Focusing on the individual DC-link capacitor voltage balancing problems caused by asymmetric parameters of independent DC loads, this paper developed a new dual modulation signals based phase disposition pulse width modulation (PD-PWM) strategy using dynamic carrier bias allocation method. Its main idea is to allocate the bias of the carrier wave dynamically according to the balance situation of the system. Compared with the traditional modulation strategies, this method is more easily to be realized and has much stronger dynamic regulation ability. This modulation strategy is widely applicable to various types of CHB structures. A detailed analysis of the DC-link capacitor charge-discharge profile is performed, and an operation condition based dynamic bias allocation method is described using the cascaded H-bridge rectifier (CHBR) structure of five sub-modules as an example. A simulation model and an experiment platform are developed, and the feasibility and effectiveness of the modulation strategy are verified by simulation and experiment results.
Quantitative Inversion of Fixed Carbon Content in Coal Gangue by Thermal Infrared Spectral Data
Authors: Song Liang , Liu Shanjun , Li Wenwen
Published: May 2019

Fixed carbon content is an important factor in measuring the carbon content of gangue, which is important for monitoring the spontaneous combustion of gangue and reusing coal gangue resources. Although traditional measurement methods of fixed carbon content, such as chemical tests, can achieve high accuracy, meeting the actual needs of mines via these tests is difficult because the measurement process is time consuming and costly and requires professional input. In this paper, we obtained the thermal infrared spectrum of coal gangue and developed a new spectral index to achieve the automated quantification of fixed carbon content. Thermal infrared spectroscopy analyses of 42 gangue and three coal samples were performed using a Turbo FT thermal infrared spectrometer. Then, the ratio index (RI), difference index (DI) and normalized difference index (NDI) were defined based on the spectral characteristics. The correlation coefficient between the spectral index and the thermal infrared spectrum was calculated, and a regression model was established by selecting the optimal spectral DI. The model prediction results were verified by a ten times 5-fold cross-validation method. The results showed that the mean error of the proposed method is 5.00%, and the root mean square error is 6.70. For comparison, the fixed carbon content was further predicted by another four methods, according to the spectral depth H, spectral area A, the random forest and support vector machine algorithms. The predicted accuracy calculated by the proposed method was the best among the five methods. Therefore, this model can be applied to predict the fixed carbon content of coal gangue in coal mines and can help guide mine safety and environmental protection, and it presents the advantages of being economic, rapid and efficient.
Investigation of Effective Thermal Conductivity for Ordered and Randomly Packed Bed with Thermal Resistance Network Method
Authors: Yang Jian , Hu Yingxue , Wang Qiuwang
Published: May 2019

In the present paper, the effective thermal conductivities of Li4SiO4-packed beds with both ordered and random packing structures were investigated using thermal resistance network methods based on both an Ohm’s law model and a Kirchhoff’s law model. The calculation results were also validated and compared with the numerical and experimental results. Firstly, it is proved that the thermal resistance network method based on the Kirchhoff’s law model proposed in the present study is reliable and accurate for prediction of effective thermal conductivities in a Li4SiO4-packed bed, while the results calculated with the Ohm’s law model underestimate both ordered and random packings. Therefore, when establishing a thermal resistance network, the thermal resistances should be connected along the main heat transfer direction and other heat transfer directions as well in the packing unit. Otherwise, both the total heat flux and effective thermal conductivity in the packing unit will be underestimated. Secondly, it is found that the effect of the packing factor is remarkable. The effective thermal conductivity of a packed bed would increase as the packing factor increases. Compared with random packing at similar packing factor, the effective thermal conductivity of packed bed would be further improved with an ordered packing method.
Biological CO2-Methanation: An Approach to Standardization
Authors: Thema Martin , Weidlich Tobias , Hörl Manuel , Bellack Annett , Mörs Friedemann , Hackl Florian , Kohlmayer Matthias , Gleich Jasmin , Stabenau Carsten , Trabold Thomas , Neubert Michael , Ortloff Felix , Brotsack Raimund , Schmack Doris , Huber Harald , Hafenbradl Doris , Karl Jürgen , Sterner Michael
Published: May 2019

Power-to-Methane as one part of Power-to-Gas has been recognized globally as one of the key elements for the transition towards a sustainable energy system. While plants that produce methane catalytically have been in operation for a long time, biological methanation has just reached industrial pilot scale and near-term commercial application. The growing importance of the biological method is reflected by an increasing number of scientific articles describing novel approaches to improve this technology. However, these studies are difficult to compare because they lack a coherent nomenclature. In this article, we present a comprehensive set of parameters allowing the characterization and comparison of various biological methanation processes. To identify relevant parameters needed for a proper description of this technology, we summarized existing literature and defined system boundaries for Power-to-Methane process steps. On this basis, we derive system parameters providing information on the methanation system, its performance, the biology and cost aspects. As a result, three different standards are provided as a blueprint matrix for use in academia and industry applicable to both, biological and catalytic methanation. Hence, this review attempts to set the standards for a comprehensive description of biological and chemical methanation processes.
Interactions of Coherent Structures on the Surface of Deep Water
Authors: Kachulin Dmitry , Dyachenko Alexander , Gelash Andrey
Published: May 2019

We numerically investigate pairwise collisions of solitary wave structures on the surface of deep water—breathers. These breathers are spatially localised coherent groups of surface gravity waves which propagate so that their envelopes are stable and demonstrate weak oscillations. We perform numerical simulations of breather mutual collisions by using fully nonlinear equations for the potential flow of ideal incompressible fluid with a free surface written in conformal variables. The breather collisions are inelastic. However, the breathers can still propagate as stable localised wave groups after the interaction. To generate initial conditions in the form of separate breathers we use the reduced model—the Zakharov equation. We present an explicit expression for the four-wave interaction coefficient and third order accuracy formulas to recover physical variables in the Zakharov model. The suggested procedure allows the generation of breathers of controlled phase which propagate stably in the fully nonlinear model, demonstrating only minor radiation of incoherent waves. We perform a detailed study of breather collision dynamics depending on their relative phase. In 2018 Kachulin and Gelash predicted new effects of breather interactions using the Dyachenko–Zakharov equation. Here we show that all these effects can be observed in the fully nonlinear model. Namely, we report that the relative phase controls the process of energy exchange between breathers, level of energy loses, and space positions of breathers after the collision.
Voting in Three-Alternative Committees: An Experiment
Authors: Goertz Johanna M.M. , Chernomaz Kirill
Published: May 2019

We design an experiment to test how voters vote in a small committee election with three alternatives. Voters have common preferences that depend on an unknown state of nature. Each voter receives an imprecise private signal prior to the election and then casts a vote. The alternative with the most votes wins. We fix the number of voters in our experiment to be five and focus on differences in the information structure (prior and signal distributions). We test three different treatments (different prior and signal distributions) that pose different challenges for the voters. In one, simply voting for one’s signal is an equilibrium. In the other two, it is not. Despite the different levels of complexity for the voters, they come relatively close to the predicted strategies (that sometimes involve mixing). As a consequence, the efficiency of the decision is also relatively high and comes close to predicted levels. In one variation of the experiment, we calculate posterior beliefs for the subjects and post them. In another, we do not. Interestingly, the important findings do not change.