bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot-stamping technology for carbon fiber reinforced thermoplastic plates based on electrical resistance heating
Authors: Okayasu Mitsuhiro , Sato Masaya
Published: October 2019

In the present work, a hot-stamping system for carbon fiber reinforced thermoplastic (CFRTP) plates based on electrical resistance heating was developed, where CFRTP consisted of polyphenylene and polyacrylonitrile. With the hot-stamping process, a simple hat-shaped sample was made. The heating rate and maximum sample temperature varied depending on the electrical resistance of the CFRTP plate. Moreover, the contact conditions between the electrodes and the CFRTP plate also affected the sample temperature owing to their influence on the electrical resistance, which was determined by the amount of exposed carbon fiber (CF) on the sample surface. Temperature measurements performed using samples with various amounts of exposed CF (20%–95% CF) revealed that approximately 65% CF afforded the highest sample temperature and fastest heating rate. The CFRTP plate underwent non-uniform heating, especially during the early stages, e.g. less than 10 s. Sample heating to 150℃ resulted in permanent deformation of the hat-shaped CFRTP samples with less springback, whereas heating to higher temperatures above the melting point led to meandering of the samples. In contrast, CFRTP samples subjected to hot-stamping at lower temperatures, such as 110℃, exhibited rough surfaces. In addition to the sample temperature, the formability of CFRTP during hot-stamping was affected by the holding time. When hot-stamping was performed without a holding time, even at high temperatures of 150℃ and above, low-quality samples with dented surfaces and irregular sample thickness were obtained. The results of this study indicate that a temperature of 150℃ and a holding time of 10 s are optimal for fabricating high-quality hot-stamped CFRTP with smooth surfaces and uniform thickness.
Aqueous extraction of buckwheat hull and its functional application in eco-friendly dyeing for wool fabric
Authors: Zhang Wei , Yao Jiming , Huang Peng , Xing Shuai
Published: October 2019

As a cheap and abundant agricultural byproduct, buckwheat hull is expected to be applied in many fields such as textile, biotechnology, and medicine. In this paper, the physicochemical properties of buckwheat hull extraction (BHE) and its dyeing abilities for wool fabric with different eco-friendly mordants and methods were studied. The theoretical process, colorfastness, and UV-protection properties of the dyed wool fabric with BHE were investigated. The results showed that BHE solution had good thermal and reduction stability. The dyeing process of BHE on wool was in accordance with the Langmuir model and had uniform monolayer adsorption. Wool fabrics dyed directly or through a mordanting process demonstrated good washing colorfastness and acceptable crocking- and light colorfastness. The dyed wool fabrics with KAl2+ and meta-mordanting showed excellent UV-protection as well as exceptional antibacterial activity against Escherichia coli. Therefore, BHE presents a novel alternative for some synthetic dyes that are applied in the textile industry.
Fluvoxamine combination therapy with tropisetron for obsessive-compulsive disorder patients: A placebo-controlled, randomized clinical trial
Authors: Shalbafan Mohammadreza , Malekpour Farzaneh , Tadayon Najafabadi Borna , Ghamari Kiandokht , Dastgheib Seyed-Ali , Mowla Arash , Shirazi Elham , Eftekhar Ardebili Mehrdad , Ghazizadeh-Hashemi Maryam , Akhondzadeh Shahin
Published: October 2019

Background:

About 50% of obsessive-compulsive disorder patients still suffer significant symptoms even after the recommended first-line therapy. This demonstrates the necessity to investigate strategies to improve alleviation of symptoms.

Objective:

The main objective of this study was to investigate the efficacy of a 5-hydroxytryptophan 3 receptor antagonist, tropisetron, as an adjuvant therapy to selective serotonin reuptake inhibitors, in ameliorating obsessive-compulsive disorder symptoms.

Methods:

Men and women between the ages of 18–60 years diagnosed with obsessive-compulsive disorder, based on DSM5, who had a Yale-Brown obsessive compulsive scale score of more than 21 were recruited in a double-blinded, parallel-group, placebo-controlled, clinical trial of 10 weeks to receive either tropisetron (5 mg twice daily) and fluvoxamine (100 mg daily initially followed by 200 mg daily after week 4) or placebo and fluvoxamine. The primary outcome of interest in this study was the Yale-Brown obsessive compulsive scale total score decrease from baseline.

Results:

One hundred and eight participants were equally randomized into two groups; 48 participants in each group finished the trial. The Yale-Brown obsessive compulsive total score significantly dropped in both groups while the tropisetron group participants experienced a significantly higher decrease in their scores (Greenhouse-Geisser F(1.53–65.87)=3.516, p-value=0.04). No major adverse effect was observed in any of the groups.

Conclusion:

This trial showed a significant efficacy for tropisetron over placebo in treatment of obsessive-compulsive disorder symptoms when added to fluvoxamine.
Influence of polymer additives on friction in fluid-film bearings: Theoretical view on experimental results by Moritsugu Kasai et al.
Authors: Kornaev Alexey V , Savin Leonid A , Kornaeva Elena P
Published: October 2019

The problem of the decrease in power loss due to friction stands permanent. One of the approaches to the solution of the problem is the application of polymer additives in order to modify the rheological properties of oils. The present theoretical work is dedicated to the analysis of experimental results of a study on polymethacrylate additives’ influence on friction that were obtained in the laboratory of Solid Mechanics of the Poitiers University. A simulation model developed in the present paper is based on the generalised Reynolds equation that takes heterogeneity of viscosity properties into account. The Reynolds equation was modified and rewritten in the bicylindrical coordinates. The geometry of the flow region could thus be described more accurately and the numerical solution could be obtained over a grid with an adaptive step. Analysis of numerical results along with experimental results allowed the identification of relationship between contents of polymer-containing oils and the hydrodynamic effect of power loss due to friction decrease as well as determination of possible reasons for contradictions that occurred during the experimental studies that are essentially a significant difference between the results for a Babbitted and a bronze bearing.
Incorporating Hope and Positivity Into Educational Policy
Authors: Dixson Dante D.
Published: October 2019

American students are underachieving relative to the nation’s investment in education. One explanation may be the lack of hope and positivity within America’s educational policies. These constructs predict student achievement and improved outcomes in several crisis areas that current educational policy has neglected (e.g., student mental health and school disciplinary practices). Moreover, educational policy can easily incorporate hope and positivity. First, schools can leverage several already-developed, effective, and scalable hope and positivity-based interventions. Second, educational policy can target hope and positivity-based constructs (e.g., student well-being) or incorporate their principles (e.g., focusing on student strengths) in education policy directed at solving problems. Given the evidence, policymakers should leverage hope and positivity in future educational policy.
Comparing the prognostic value of geriatric health indicators: a population-based study
Authors: Zucchelli Alberto , Vetrano Davide L. , Grande Giulia , Calderón-Larrañaga Amaia , Fratiglioni Laura , Marengoni Alessandra , Rizzuto Debora
Published: October 2019

Background

The identification of individuals at increased risk of poor health-related outcomes is a priority. Geriatric research has proposed several indicators shown to be associated with these outcomes, but a head-to-head comparison of their predictive accuracy is still lacking. We therefore aimed to compare the accuracy of five geriatric health indicators in predicting different outcomes among older persons: frailty index (FI), frailty phenotype (FP), walking speed (WS), multimorbidity, and a summary score including clinical diagnoses, functioning, and disability (the Health Assessment Tool; HAT).

Methods

Data were retrieved from the Swedish National Study on Aging and Care in Kungsholmen, an ongoing longitudinal study including 3363 people aged 60+. To inspect the accuracy of geriatric health indicators, we employed areas under the receiver operating characteristic curve (AUC) for the prediction of 3-year and 5-year mortality, 1-year and 3-year unplanned hospitalizations (1+), and contacts with healthcare providers in the 6 months before and after baseline evaluation (2+).

Results

FI, WS, and HAT showed the best accuracy in the prediction of mortality [AUC(95%CI) for 3-year mortality 0.84 (0.82–0.86), 0.85 (0.83–0.87), 0.87 (0.85–0.88) and AUC(95%CI) for 5-year mortality 0.84 (0.82–0.86), 0.85 (0.83–0.86), 0.86 (0.85–0.88), respectively]. Unplanned hospitalizations were better predicted by the FI [AUC(95%CI) 1-year 0.73 (0.71–0.76); 3-year 0.72 (0.70–0.73)] and HAT [AUC(95%CI) 1-year 0.73 (0.71–0.75); 3-year 0.71 (0.69–0.73)]. The most accurate predictor of multiple contacts with healthcare providers was multimorbidity [AUC(95%CI) 0.67 (0.65–0.68)]. Predictions were generally less accurate among younger individuals (< 78 years old).

Conclusion

Specific geriatric health indicators predict clinical outcomes with different accuracy. Comprehensive indicators (HAT, FI, WS) perform better in predicting mortality and hospitalization. Multimorbidity exhibits the best accuracy in the prediction of multiple contacts with providers.
Tissue diagnosis during colorectal cancer surgery using optical sensing: an in vivo study
Authors: Baltussen E. J. M. , Brouwer de Koning S. G. , Sanders J. , Aalbers A. G. J. , Kok N. F. M. , Beets G. L. , Hendriks B. H. W. , Sterenborg H. J. C. M. , Kuhlmann K. F. D. , Ruers T. J. M.
Published: October 2019

Background

In colorectal cancer surgery there is a delicate balance between complete removal of the tumor and sparing as much healthy tissue as possible. Especially in rectal cancer, intraoperative tissue recognition could be of great benefit in preventing positive resection margins and sparing as much healthy tissue as possible. To better guide the surgeon, we evaluated the accuracy of diffuse reflectance spectroscopy (DRS) for tissue characterization during colorectal cancer surgery and determined the added value of DRS when compared to clinical judgement.

Methods

DRS spectra were obtained from fat, healthy colorectal wall and tumor tissue during colorectal cancer surgery and results were compared to histopathology examination of the measurement locations. All spectra were first normalized at 800 nm, thereafter two support vector machines (SVM) were trained using a tenfold cross-validation. With the first SVM fat was separated from healthy colorectal wall and tumor tissue, the second SVM distinguished healthy colorectal wall from tumor tissue.

Results

Patients were included based on preoperative imaging, indicating advanced local stage colorectal cancer. Based on the measurement results of 32 patients, the classification resulted in a mean accuracy for fat, healthy colorectal wall and tumor of 0.92, 0.89 and 0.95 respectively. If the classification threshold was adjusted such that no false negatives were allowed, the percentage of false positive measurement locations by DRS was 25% compared to 69% by clinical judgement.

Conclusion

This study shows the potential of DRS for the use of tissue classification during colorectal cancer surgery. Especially the low false positive rate obtained for a false negative rate of zero shows the added value for the surgeons.

Trail registration This trail was performed under approval from the internal review board committee (Dutch Trail Register NTR5315), registered on 04/13/2015, https://www.trialregister.nl/trial/5175.
Preterm births and associated factors among mothers who gave birth in Axum and Adwa Town public hospitals, Northern Ethiopia, 2018
Authors: Aregawi Gebrekiros , Assefa Nega , Mesfin Firehiwot , Tekulu Fissaha , Adhena Tesfay , Mulugeta Mussie , Gebreayezgi Guesh
Published: October 2019

Objective

The objective of this study was to determine the prevalence and associated factors of preterm births among mothers who gave birth in Axum and Adwa public hospitals, Tigray, North Ethiopia, 2018.

Result

This study showed that 13.3% from the total 472 mothers gave a preterm birth. Being a rural resident (AOR = 2.13, 95% CI (1.07,4.22), short inter pregnancy interval (AOR = 5.4, 95% CI (1.32, 22.05), previous preterm birth (AOR = 3.74, 95% CI (1.03, 16.34), Premature rupture of membrane (AOR = 4.14, 95% CI (1.92, 8.89), induced onset of labor (AOR = 2.49, 95% CI (1.06, 5.85) multiple pregnancy (AOR = 5.69, 95% CI (2.27, 14.28), malaria during pregnancy (AOR = 4.71, 95% CI (1.98, 11.23), Presence of chronic illness (AOR = 4.55, 95% CI (1.83, 11.26) were significantly associated with preterm birth.
HutZ is required for biofilm formation and contributes to the pathogenicity of Edwardsiella piscicida
Authors: Shi Yan-Jie , Fang Qing-Jian , Huang Hui-Qin , Gong Chun-Guang , Hu Yong-Hua
Published: October 2019

Edwardsiella piscicidais a severe fish pathogen. Haem utilization systems play an important role in bacterial adversity adaptation and pathogenicity. In this study, a speculative haem utilization protein, HutZEp, was characterized inE. piscicida.hutZEpis encoded with two other genes,hutWandhutX, in an operon that is similar to the haem utilization operonhutWXZidentified inV. cholerae. However, protein activity analysis showed that HutZEpis probably not related to hemin utilization. To explore the biological role of HutZEp, a markerlesshutZEpin-frame mutant strain, TX01ΔhutZ, was constructed. Deletion ofhutZEpdid not significantly affect bacterial growth in normal medium, in iron-deficient conditions, or in the presence of haem but significantly retarded bacterial biofilm growth. The expression of known genes related to biofilm growth was not affected byhutZEpdeletion, which indicated that HutZEpwas probably a novel factor promoting biofilm formation inE. piscicida. Compared to the wild-type TX01, TX01ΔhutZexhibited markedly compromised tolerance to acid stress and host serum stress. Pathogenicity analysis showed that inactivation ofhutZEpsignificantly impaired the ability ofE. piscicidato invade and reproduce in host cells and to infect host tissue. In contrast to TX01, TX01ΔhutZwas defective in blocking host macrophage activation. The expression ofhutZEpwas directly regulated by the ferric uptake regulator Fur. This study is the first functional characterization of HutZ in a fish pathogen, and these findings suggested that HutZEpis essential forE. piscicidabiofilm formation and contributes to host infection.
Direct admission to the intensive care unit from the emergency department and mortality in critically ill hematology patients
Authors: Peyrony Olivier , Chevret Sylvie , Meert Anne-Pascale , Perez Pierre , Kouatchet Achille , Pène Frédéric , Mokart Djamel , Lemiale Virginie , Demoule Alexandre , Nyunga Martine , Bruneel Fabrice , Lebert Christine , Benoit Dominique , Mirouse Adrien , Azoulay Elie
Published: October 2019

Background

The aim of this study was to assess the benefit of direct ICU admission from the emergency department (ED) compared to admission from wards, in patients with hematological malignancies requiring critical care.

Methods

Post hoc analysis derived from a prospective, multicenter cohort study of 1011 critically ill adult patients with hematologic malignancies admitted to 17 ICU in Belgium and France from January 2010 to May 2011. The variable of interest was a direct ICU admission from the ED and the outcome was in-hospital mortality. The association between the variable of interest and the outcome was assessed by multivariable logistic regression after multiple imputation of missing data. Several sensitivity analyses were performed: complete case analysis, propensity score matching and multivariable Cox proportional-hazards analysis of 90-day survival.

Results

Direct ICU admission from the ED occurred in 266 (26.4%) cases, 84 of whom (31.6%) died in the hospital versus 311/742 (41.9%) in those who did not. After adjustment, direct ICU admission from the ED was associated with a decreased in-hospital mortality (adjusted OR: 0.63; 95% CI 0.45–0.88). This was confirmed in the complete cases analysis (adjusted OR: 0.64; 95% CI 0.45–0.92) as well as in terms of hazard of death within the 90 days after admission (adjusted HR: 0.77; 95% CI 0.60–0.99). By contrast, in the propensity score-matched sample of 402 patients, direct admission was not associated with in-hospital mortality (adjusted OR: 0.92; 95% CI 0.84–1.01).

Conclusions

In this study, patients with hematological malignancies admitted to the ICU were more likely to be alive at hospital discharge if they were directly admitted from the ED rather than from the wards. Assessment of early predictors of poor outcome in cancer patients admitted to the ED is crucial so as to allow early referral to the ICU and avoid delays in treatment initiation and mis-orientation.
Predicting Ailanthus altissima presence across a managed forest landscape in southeast Ohio
Authors: Iverson Louis R. , Rebbeck Joanne , Peters Matthew P. , Hutchinson Todd , Fox Timothy
Published: October 2019

Background

The negative impacts of the exotic tree,Ailanthus altissima(tree-of-heaven, stink tree), is spreading throughout much of the Eastern United States. When forests are disturbed, it can invade and expand quickly if seed sources are nearby.

Methods

We conducted studies at the highly dissected Tar Hollow State Forest (THSF) in southeastern Ohio USA, whereAilanthusis widely distributed within the forest, harvests have been ongoing for decades, and prescribed fire had been applied to about a quarter of the study area. Our intention was to develop models to evaluate the relationship ofAilanthuspresence to prescribed fire, harvesting activity, and other landscape characteristics, using this Ohio location as a case study. Field assessments of the demography ofAilanthusand other stand attributes (e.g., fire, harvesting, stand structure) were conducted on 267 sample plots on a 400-m grid throughout THSF, supplemented by identification ofAilanthusseed-sources via digital aerial sketch mapping during the dormant season. Statistical modeling tools Random Forest (RF), Classification and Regression Trees (CART), and Maxent were used to assess relationships among attributes, then model habitats suitable forAilanthuspresence.

Results

In all, 41 variables were considered in the models, including variables related to management activities, soil characteristics, topography, and vegetation structure (derived from LiDAR). The most important predictor ofAilanthuspresence was some measure of recent timber harvest, either mapped harvest history (CART) or LiDAR-derived canopy height (Maxent). Importantly, neither prescribed fire or soil variables appeared as important predictors ofAilanthuspresence or absence in any of the models of the THSF.

Conclusions

These modeling techniques provide tools and methodologies for assessing landscapes forAilanthusinvasion, as well as those areas with higher potentials for invasion should seed sources become available. Though a case study on an Ohio forest, these tools can be modified for use anywhereAilanthusis invading.
Facies-based seismic inversion for a field development plan
Authors: Naeini Ehsan Zabihi , Nasseri Jalil
Published: October 2019

Field appraisal and development plans aim to provide the best technical solution for optimizing hydrocarbon production and require integration between various disciplines including geology, geophysics, engineering, well planning, and environmental sciences. Seismic inversion could provide one essential component for reservoir modeling in support of appraisal and development evaluations. Therefore, it is important to quantitatively assess all of the possibilities and uncertainties involved in reservoir definition and extension. A probabilistic facies-based seismic inversion method has been utilized to achieve this goal in a recent Central North Sea discovery. The probabilistic nature of the inversion allows computation of various scenarios. We categorically selected, among others, most likely, optimistic, and pessimistic scenarios based on prior knowledge and calibration at the wells. Then, we performed a statistical analysis of all of the scenarios to identify the uncertainties. We also performed a postinversion forward-modeling study to assess uncertainties that may be related to thin layers of subseismic resolution.
HSSE Committee provides tools, support to promote member safety
Authors: Decker Luke
Published: October 2019

SEG's Health, Safety, Security, and Environment (HSSE) Committee has been working to provide tools and assistance to improve member awareness of risks and empower them to better mitigate associated hazards. In particular, the committee focuses its activities on supporting field activities, including SEG-sponsored field camps and Geoscientists Without Borders®, providing readily available and accessible HSSE guidance resources. Recent efforts have involved helping field camp planners ensure that their activities are completed as smoothly and safely as possible and providing resources to help Society members as a whole.
Multidisciplinary Software Design for the Routine Monitoring and Assessment of Pain in Palliative Care Services: The Development of PainCheck
Authors: Allsop Matthew J. , Johnson Owen , Taylor Sally , Hackett Julia , Allen Peter , Bennett Michael I. , Bewick Bridgette M.
Published: October 2019

PURPOSE

The use of health information technology (HIT) to support patient and health professional communication is emerging as a core component of modern cancer care. Approaches to HIT development for cancer care are often underreported, despite their implementation in complex, multidisciplinary environments, typically supporting patients with multifaceted needs. We describe the development and evaluation of an e-health tool for pain management in patients with advanced cancer, arising from collaboration between health researchers and a commercial software development company.

METHODS

We adopted a research-led development process, involving patients with advanced cancer and their health professionals, focusing on use within real clinical settings. A software development approach (disciplined agile delivery) was combined with health science research methods (ie, diary studies, face-to-face interviews, questionnaires, prototyping, think aloud, process reviews, and pilots). Three software iterations were managed through three disciplined agile delivery phases to develop PainCheck and prepare it for use in a clinical trial.

RESULTS

Findings from development phases (inception, elaboration, and construction) informed the design and implementation of PainCheck. During the transition phase, where PainCheck was evaluated in a randomized clinical trial, there was variation in the extent of engagement by patients and health professionals. Prior personal experience and confidence with HIT led to a gatekeeping effect among health professionals, who were reluctant to introduce PainCheck to patients. Patients who did use PainCheck seemed to benefit, and no usability issues were reported.

CONCLUSION

Health science research methods seemed to help in the development of PainCheck, although a more rigorous application of implementation science methodologies might help to elucidate further the barriers and facilitators to adoption and inform an evidence-based plan for future implementation.
Clinical Data Extraction and Normalization of Cyrillic Electronic Health Records Via Deep-Learning Natural Language Processing
Authors: Zhao Boyang
Published: October 2019

PURPOSE

A substantial portion of medical data is unstructured. Extracting data from unstructured text presents a barrier to advancing clinical research and improving patient care. In addition, ongoing studies have been focused predominately on the English language, whereas inflected languages with non-Latin alphabets (such as Slavic languages with a Cyrillic alphabet) present numerous linguistic challenges. We developed deep-learning–based natural language processing algorithms for automatically extracting biomarker status of patients with breast cancer from three oncology centers in Bulgaria.

METHODS

We used dual embeddings for English and Bulgarian languages, encoding both syntactic and polarity information for the words. The embeddings were subsequently aligned so that they were in the same vector space. The embeddings were used as input to convolutional or recurrent neural networks to derive the biomarker status of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.

RESULTS

We showed that we can resolve ambiguity in highly variable medical text containing both Latin and Cyrillic text. Final models incorporating both English and Bulgarian syntax and polarity embeddings achieved F1 scores of 0.90 or higher for all estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 biomarkers. The models were robust against human errors originally found in the training set. In addition, such models can be extended for analyzing text containing words not seen during training.

CONCLUSION

By using several techniques that incorporate dual-word embeddings encoding syntactic and polarity information in two languages followed by deep neural network architectures, we show that researchers can extract and normalize parameters within medical data. The principles described here can be used to analyze Cyrillic or Latin mixed medical text and extract other parameters.
Effect of Public Deliberation on Patient Attitudes Regarding Consent and Data Use in a Learning Health Care System for Oncology
Authors: Jagsi Reshma , Griffith Kent A. , Jones Rochelle D. , Krenz Chris , Gornick Michele , Spence Rebecca , De Vries Raymond , Hawley Sarah T. , Zon Robin , Bolte Sage , Sadeghi Navid , Schilsky Richard L. , Bradbury Angela R.
Published: October 2019

PURPOSE

We sought to generate informed and considered opinions regarding acceptable secondary uses of deidentified health information and consent models for oncology learning health care systems.

METHODS

Day-long democratic deliberation sessions included 217 patients with cancer at four geographically and sociodemographically diverse sites. Patients completed three surveys (at baseline, immediately after deliberation, and 1-month follow-up).

RESULTS

Participants were 67.3% female, 21.7% black, and 6.0% Hispanic. The most notable changes in perceptions after deliberation related to use of deidentified medical-record data by insurance companies. After discussion, 72.3% of participants felt comfortable if the purpose was to make sure patients receive recommended care ( v 79.5% at baseline; P = .03); 24.9% felt comfortable if the purpose was to determine eligibility for coverage or reimbursement ( v 50.9% at baseline; P < .001). The most notable change about secondary research use related to believing it was important that doctors ask patients at least once whether researchers can use deidentified medical-records data for future research. The proportion endorsing high importance decreased from baseline (82.2%) to 68.7% immediately after discussion ( P < .001), and remained decreased at 73.1% ( P = .01) at follow-up. At follow-up, non-Hispanic whites were more likely to consider it highly important to be able to conduct medical research with deidentified electronic health records (96.8% v 87.7%; P = .01) and less likely to consider it highly important for doctors to get a patient’s permission each time deidentified medical record information is used for research (23.2% v 51.6%; P < .001).

CONCLUSION

This research confirms that most patients wish to be asked before deidentified medical records are used for research. Policies designed to realize the potential benefits of learning health care systems can, and should be, grounded in informed and considered public opinion.
Black Seed Oil and Perioperative Serotonin Syndrome: A Case Report
Authors: Warner Mary E. , Warner Paul A. , Sprung Juraj , Warner Mark A.
Published: October 2019

Perioperative serotonin syndrome has been associated with a number of medications and herbal supplements. We report a patient who developed serotonin syndrome immediately after an endoscopic procedure in which the preoperative use of black seed oil appears to have played a role in stimulating the syndrome. Black seed oil has not been previously reported in association with perioperative serotonin syndrome. Anesthesia professionals should be aware that patients taking black seed oil supplements may develop serotonin syndrome postoperatively.
Spontaneous Resolution of Gravid Uterine Incarceration With Spinal Anesthesia: A Case Report
Authors: Hire Matthew G. , Reynolds Kyle E. , Farrer Jason R.
Published: October 2019

Incarceration of the gravid uterus may pose significant risks to both maternal and fetal health. Anesthetic management for these patients is variable, and the ideal anesthetic technique is unknown. The patient presented to the labor and delivery unit with pelvic pain and urinary retention in the setting of a gravid incarcerated uterus. Previous attempts at manual reduction in the outpatient setting were unsuccessful. A combined spinal-epidural anesthetic was administered, followed by spontaneous resolution of the incarcerated uterus. In addition to providing analgesia, neuraxial blockade may occasionally be an adequate therapeutic technique for reduction of a gravid incarcerated uterus.
Oxygenation of Styrenes Catalyzed by N-Doped Carbon Incarcerated Cobalt Nanoparticles
Authors: Yasukawa Tomohiro , Kobayashi Shū
Published: October 2019

We found that cobalt nanoparticle catalysts supported on nitrogen-doped carbon could facilitate oxygenation of styrenes in a heterogeneous manner. Both the nitrogen dopant and cobalt species were essential to promote the reactions. Based on several mechanistic studies, the formation of radical intermediates on cobalt nanoparticles is proposed.
Planos de Opções de Compra de Ações e o Valor das Companhias Brasileiras
Authors: Perobelli Fernanda Finotti Cordeiro , Lopes Bruno de Souza , Silveira Alexandre Di Miceli da
Published: October 2019

Este trabalho tem por objetivo investigar os efeitos dos Planos de Opções de Compra de Ações, internacionalmente conhecidos como Employee Stock Options Plans (ESOP), sobre o valor das empresas listadas na BM&FBOVESPA. O ESOP é um mecanismo de remuneração variável, geralmente fornecido a executivos, sendo um dos objetivos de sua adoção o alinhamento de interesses entre gestores e acionistas. Para atingir o objetivo proposto, foi utilizada a análise de dados em painel, que procurou mensurar se a presença do ESOP gera ou não valor ao acionista. Os resultados mostram que há indícios de que o ESOP gera riqueza ao acionista, mas apenas quando este é feito de forma bem estruturada em relação ao preço de exercício, ou seja, quando este é fixado at-money ou out-of-money. A valorização do preço das ações é ampliada quando as empresas apresentam práticas melhores de governança corporativa e quando apresentam ESOP há mais de três anos.
Relatório Editorial - 2011
Authors: Leal Ricardo Pereira Câmara
Published: October 2019

A RBFin é o principal veículo para publicação de artigos acadêmicos em finanças do Brasil. O conteúdo da Revista permaneceu on-line e aberto e também foi mantida a revista impressa, graças ao auxílio do CNPq/Capes. A revista emprega o sistema Open Journal System para gerenciar o processo editorial. O cronograma de publicação da RBFin encontra-se rigorosamente em dia. A revista é indexada no EconLit, Google Scholar, Ebsco e Gale e listada nos diretórios JEL, DOAJ, Latindex, OpenJGate e Cabell’s. A RBFin foi enquadrada como B1 na área de Administração do Qualis/Capes. O Corpo Editorial Científico é parcialmente renovado a cada ano e é formado por 18 membros provenientes de quatro países, sendo nove de cinco diferentes estados do Brasil. A taxa de aceitação foi de 30% para os artigos enviados em 2010, o último ano em que todos os artigos já obtiveram decisão definitiva. A média de dias entre o recebimento e a aceitação para os artigos publicados em 2011 foi de 266. O pior caso foi de 462 dias. A média de dias entre o recebimento e a publicação foi de 432. O pior caso foi de 599 dias. O número médio de acessos por artigo foi de 1.249. Sessenta e quatro indivíduos atuaram como avaliadores em 2011.
Reversão à Média com Tendência e Opções Reais na Siderurgia
Authors: Ozorio Luiz de Magalhães , Bastian-Pinto Carlos de Lamare , Baidya Tara Nanda , Brandão Luiz Eduardo Teixeira
Published: October 2019

O aço é uma commodity de grande variabilidade de preços e a escolha do processo estocástico que melhor represente suas possíveis trajetórias no tempo é fundamental para avaliação de opções reais em projetos siderúrgicos. Como verificado em outras commodities, entende-se que os preços do aço possam ser guiados por um componente de reversão à média, mas a análise de algumas questões econômicas ligadas à sua produção sugerem que estes preços possuam também componentes de tendência ascendente, que elevam sua média de longo prazo à medida que o tempo evolui. Este trabalho apresenta um modelo denominado Reversão à Média com Tendência (MRM-T), no qual é incorporada uma tendência determinística ao nível de equilíbrio de longo prazo com a intenção de capturar o aumento do custo marginal de produção do aço e analisa as implicações do uso desse modelo na avaliação de projetos na indústria siderúrgica.
Técnicas Quantitativas de Otimização de Carteiras Aplicadas ao Mercado de Ações Brasileiro
Authors: Santos André Alves Portela , Tessari Cristina
Published: October 2019

Neste artigo examinamos a aplicabilidade e o desempenho fora da amostra das estratégias quantitativas de otimização por média-variância e mínima-variância com relação ao desempenho da carteira ingênua igualmente ponderada (1/N) e da carteira teórica do índice Ibovespa, bem como avaliamos a estabilidade das composições ótimas obtidas. Na obtenção de carteiras ótimas, restritas para venda a descoberto, foram empregadas matrizes de covariâncias estimadas com base em cinco abordagens alternativas: matriz de covariância amostral, matriz RiskMetrics, e três estimadores propostos por Ledoit & Wolf (2003), Ledoit & Wolf (2004a) e Ledoit & Wolf (2004b). Tomando como base diferentes frequências de rebalanceamento das carteiras, as medidas de desempenho fora da amostra indicam que as estratégias quantitativas de otimização proporcionam resultados estatisticamente significativos em termos de menor volatilidade e desempenho ajustado ao risco superior. Além disso, o uso de estimadores mais sofisticados para a matriz de covariâncias gerou carteiras com menor turnover ao longo do tempo.
Medidas de Risco e Matriz de Contágio: uma Aplicação do CoVaR para o Mercado Financeiro Brasileiro
Authors: Almeida Aléssio Tony Cavalcanti de , Frascaroli Bruno Ferreira , Cunha Danilo Regis da
Published: October 2019

O objetivo central deste trabalho é avaliar como um distress nas séries de retornos de importantes papéis de empresas brasileiras e dos principais indicadores do mercado financeiro doméstico (Ibovespa) e internacional (Dow Jones) interagem entre si, numa tentativa de captar spillover effects. Mais precisamente, estimou-se o risco sistêmico, o efeito contágio e o stress test. Para o cálculo de tais indicadores é utilizada a abordagem CoVaR, apresentada em Adrian e Brunnermeier (2011), em que os parâmetros de interesse são estimados através de regressores quantílicos. Uma novidade apresentada neste trabalho é a construção de uma matriz de contágios para o mercado doméstico de capitais, que mede as inter-relações entre a rentabilidade dos papéis de empresas em um ambiente de distress financeiro. Os principais resultados apontam a inexistência de correlação entre as medidas de risco dadas pelo Value at Risk (VaR) e pelo CoVaR, bem como o risco sistêmico sinaliza aqueles papéis que geram mais externalidades negativas para o mercado financeiro doméstico. Através do stress test verifica-se que um distress nos retornos do Ibovespa possui mais spillover effects sobre os papéis das empresas que atuam na BM&FBovespa do que um distress nos retornos do mercado internacional. Por fim, pela matriz de contágios, nota-se que as inter-relações de contágios entre os retornos dos papéis das empresas evidenciam indícios setoriais para avaliação e gestão de riscos.
Opacidade e Assunção de Risco pelos Bancos
Authors: Behr Patrick
Published: October 2019

Este artigo investiga a relação entre a opacidade e a assunção de risco pelos bancos. Usando uma amostra de 199 bancos de 38 países no período de janeiro de 1996 a dezembro de 2006, analisamos se bancos mais opacos são maiores tomadores de risco do que os bancos menos opacos. Encontramos evidências substantivas de que as proxies comumente usadas para medir a opacidade bancária são significamente relacionadas à assunção de risco pelos bancos, tal como medidas pela PD de Merton e Z-score de cada banco individualmente, mesmo após levar em consideração a simultaneidade potencial entre assunção de risco e opacidade. Os bancos mais opacos parecem estar engajados na maior assunção de risco do que os bancos menos opacos. Este resultado fornece suporte para a visão comumente aceita de que a opacidade é problemática e que a transparência entre instituições financeiras deveria aumentar.
Conteúdo Informacional dos Ratings de Crédito no Brasil: Um Estudo de Evento
Authors: Murcia Flávia Cruz de Souza , Murcia Fernando Dal-Ri , Borba José Alonso
Published: October 2019

Este estudo analisa o efeito de anúncios de rating de crédito nos retornos de ações no mercado brasileiro no período de 1977 a 2011. Foi conduzido um estudo de evento utilizando uma amostra de 242 observações de companhias abertas, sendo 179 da Standard and Poor’s e 63 da Moody’s, para analisar a reação do mercado acionário. Os retornos anormais foram calculados utilizando o Market Model e o CAPM para três janelas de evento: três dias (-1, +1), 11 dias (-5, +5) e 21 dias (-10, +10). Foram encontrados retornos anormais estatisticamente significativos nos dias -1 e 0 e para todos os três tipos de anúncios testados: ratings iniciais, downgrades e upgrades. No caso dos downgrades, consistente com os estudos anteriores, os resultados também mostraram retornos anormais negativos para praticamente todas as janelas testadas. De modo geral, os resultados evidenciaram que os anúncios de rating possuem conteúdo informacional, uma vez que impactam nos retornos das ações, especialmente quando eles trazem ‘más notícias’ ao mercado.
Avaliando a Volatilidade Diária dos Ativos: a Hora da Negociação Importa?
Authors: Vicente José Valentim Machado , Araujo Gustavo Silva , Castro Paula Baião Fisher de , Tavares Felipe Noronha
Published: October 2019

O objetivo deste estudo é examinar se investidores que negociam diariamente, mas em momentos diferentes, têm percepções distintas acerca do risco de um ativo. A fim de capturar as incertezas enfrentadas por esses investidores, definimos a volatilidade percebida como a distribuição de desvios-padrão de retornos diários calculados a partir de preços intradiários coletados aleatoriamente. Nós concluímos que essa distribuição tem um alto grau de dispersão, o que quer dizer que diferentes investidores podem não ter a mesma opinião sobre a variabilidade dos retornos do mesmo ativo. Além disso, a volatilidade close-to-close é muitas vezes menor que a mediana da distribuição de volatilidade percebida pelos investidores, enquanto a open-to-open é maior que essa estatística. De um ponto de vista prático, nossos resultados indicam que as volatilidades estimadas com o uso de amostras tradicionais de retornos diários (ou seja, retornos close-to-close e open-to-open) podem não fazer um bom trabalho quando empregadas em modelos financeiros, já que podem não captar os riscos aos quais os investidores estão expostos.
A Oferta de Trade Credit Pelas Empresas Brasileiras de Capital Aberto
Authors: Schiozer Rafael Felipe , Brando João Alberto Peres
Published: October 2019

Esse artigo investiga os determinantes da oferta de trade credit por companhias brasileiras de capital aberto, no período de 2005 a 2008. A teoria financeira encontra sustentação em estudos empíricos internacionais, que documentam que os principais determinantes são o tamanho e o nível de endividamento das firmas, ambos indicando a disponibilidade de recursos nas firmas como fatores significantes na oferta de trade credit. Adicionalmente, esta literatura confirma usos estratégicos para o trade credit, como discriminação de preços entre clientes. Os resultados obtidos no presente estudo, utilizando-se uma amostra de 157 empresas brasileiras, não dão sustentação às primeiras hipóteses, mas endossam a oferta de trade credit como elemento estratégico para estas firmas. Foi ainda observada uma significativa queda na oferta de trade credit em 2008, ano marcado por uma aguda crise financeira internacional.
Small Worlds e Board Interlocking no Brasil: Estudo Longitudinal das Redes Corporativas, 1997-2007
Authors: Mendes-da-Silva Wesley
Published: October 2019

A Análise de Redes Sociais (ARS) é um campo emergente de pesquisa em Finanças, sobretudo no Brasil. De forma pioneira, este trabalho apoia-se em referenciais de diferentes áreas do conhecimento: análise de redes sociais e governança corporativa, para tratar um tópico similarmente emergente em finanças, o board interlocking, o objetivo é verificar a validade do modelo de small worlds no mercado de capitais brasileiro e a existência de associações entre o posicionamento da firma na rede de relações corporativas e o seu valor. Para tanto, foram empregados dados oficiais relativos a mais de 400 empresas listadas no Brasil entre 1997 e 2007. Os principais resultados obtidos sugerem que a configuração das redes de relações entre os membros de conselhos e entre empresas reflete o modelo de small world. Além disso, parece existir uma relação significativa entre a centralidade da firma e o seu valor, descrita segundo uma curva do tipo “U invertido”, o que sugere a existência de valores ótimos de proeminência social na rede corporativa.
Desempenho e Persistência de Hedge Funds Brasileiros Durante a Crise Financeira
Authors: Joaquim Gustavo Passarelli Giroud , Moura Marcelo Leite
Published: October 2019

Este estudo investiga o desempenho e a persistência do mercado de fundos de hedge no Brasil utilizando dados diários de setembro de 2007 a fevereiro de 2011, um período marcado pelo que foi caracterizado por muitos como a pior crise financeira mundial desde a grande depressão dos anos 1930. Apesar da turbulência nos mercados globais, os resultados indicam a existência de um grupo representativo de fundos com retornos anormais e evidência de persistência conjunta de fundos com prazos de um a três meses. Avaliações individuais dos fundos, no entanto, indicam um número reduzido de fundos que apresentam persistência.
Volume 9 (2011) - Índices
Authors: Leal Ricardo Pereira Câmara
Published: October 2019

Índices por nome do autor, título do artigo e tema do artigo. Em inglês.
Protocol for an app-based affective control training for adolescents: proof-of-principle double-blind randomized controlled trial
Authors: Schweizer Susanne , Leung Jovita T. , Kievit Rogier , Speekenbrink Maarten , Trender William , Hampshire Adam , Blakemore Sarah-Jayne
Published: October 2019

Background: 75% of all mental health problems have their onset before the end of adolescence. Therefore, adolescence may be a particularly sensitive time period for preventing mental health problems. Affective control, the capacity to engage with goal relevant and inhibit distracting information in affective contexts, has been proposed as a potential target for prevention. In this study, we will explore the impact of improving adolescents’ affective control capacity on their mental health.

Methods: The proof-of-principle double-blind randomized controlled trial will compare the effectiveness of an app-based affective control training (AffeCT) to a placebo training (P-Training) app. In total, 200 (~50% females) adolescents (11-19 years) will train for 14 days on their training app. The AffeCT will include three different n-back tasks: visuospatial, auditory and dual (i.e., including both modalities). These tasks require participants to flexibly engage and disengage with affective and neutral stimuli (i.e., faces and words). The P-Training will present participants with a perceptual matching task. The three versions of the P-Training tasks vary in the stimuli included (i.e., shapes, words and faces). The two training groups will be compared on gains in affective control, mental health, emotion regulation and self-regulation, immediately after training, one month and one year after training.

Discussion: If, as predicted, the proposed study finds that AffeCT successfully improves affective control in adolescents, there would be significant potential benefits to adolescent mental health. As a free app, the training would also be scalable and easy to disseminate across a wide range of settings.

Trial registration: The trial was registered on December 10th 2018 with the International Standard Randomised Controlled Trial Number (Registration number: ISRCTN17213032).
Libertarian Paternalism or Paternalistic Welfarism — NUDGES Viewed through the Orwellian Looking Glass
Authors: John Jaison
Published: October 2019

Libertarian paternalism is often considered as an oxymoron that uses the means of libertarianism to meet the ends of paternalism. It is considered as paternalistic as it covertly transforms into a paternalistic apparatus through the endorsement of the choices the State/authority wants people to make. It is argued that since libertarian paternalism invokes incentives which works differently than coercion, this paper and various other scholars reiterate and respond by arguing that the mere replacement of coercion with incentives does not make libertarian paternalism less paternalistic. A libertarian paternal State exploits the malleability of men to mould their behaviour according to the propositions of the ruling class which the rulers often assert to be in the best interests of the masses. In this article, Orwell‟s Animal Farm, would be used as an analogy to unpack and conceptually analyse the ethical implications of libertarian paternalism.
Open Problem—Adaptive Constant-Step Stochastic Approximation
Authors: Pasupathy Raghu , Honnappa Harsha , Hunter Susan R.
Published: October 2019

Suppose [Formula: see text] is a smooth function that is bounded from below. The classic stochastic approximation (SA) recursion used to identify a stationary point of [Formula: see text] is given by[Formula: see text]where [Formula: see text] and [Formula: see text] is a sequence of independent and identically distributed random fields defined on some filtered probability space [Formula: see text] such that [Formula: see text] almost surely (a.s.) for all [Formula: see text].