bluuebunny/crossref_metadata_2025 huggingface dataset:
The Gender Gap in Business Leadership: Exploring an Affect Control Theory Explanation
Authors: Kroska Amy , Cason Trent C.
Published: January 2019

We use affect control theory (ACT) and its computer simulation program, Interact, to theoretically model the interactional dynamics that women and men business executives are likely to face in the workplace, and we show how these dynamics may contribute to the gender gap in business leadership. Using data from 520 simulated events and two analysis strategies, we use ACT to develop empirically grounded hypotheses regarding these processes. The simulations suggest that women executives face a wider range of situations that require gender deviance than men executives, many of which may be unavoidable (e.g., confronting an unreliable employee). They also suggest that observers will attribute negative characteristics to both women and men executives who engage in a gender-deviant action but that the characteristics attributed to gender-deviant women executives (e.g., ruthless, sadistic) move their identity further from the affective meaning of “an executive” than the characteristics attributed to comparably gender-deviant men executives (e.g., awestruck, gullible), patterns that are likely to make the path to and retention of business leadership positions more difficult for women. We also discuss how our approach could be used to theorize about interactional processes underlying other inequalities, including those based on race, ethnicity, class, sexual orientation, disability, and age.
The effect of methylprednisolone prophylaxis on inflammatory monocyte subsets and suppressive regulatory T cells of patients undergoing cardiopulmonary bypass
Authors: Hao Xing , Han Junyan , Zeng Hui , Wang Hong , Li Guoli , Jiang Chunjing , Xing Zhichen , Hao Yu , Yang Feng , Hou Xiaotong
Published: January 2019

Background:

Cardiopulmonary bypass (CPB) during open-heart surgery triggers an inflammatory response that can cause significant morbidity and mortality. Human monocytes and regulatory T (Treg) cells are phenotypically and functionally heterogeneous and have been shown to play a significant role in the inflammatory dysfunction triggered by CPB. Glucocorticoids (GCs) have been widely administered for decades in patients undergoing CPB to reduce this inflammatory response. However, it has not been clearly established how routine prophylactic administration of glucocorticoids (GCs) affects monocyte and Treg subsets.

Methods:

Thirty-six patient who underwent heart surgery with CPB were randomly assigned to a methylprednisolone group (MG, N = 18; 500 mg in the CPB priming) and a non-methylprednisolone group (NMG, N = 18). The circulating monocyte and Treg subsets were analyzed by flow cytometry.

Results:

The MG and NMG groups had comparable percentages of monocyte subsets and similar expression levels of HLA-DR, CD86, CD64 and toll-like receptor 4 (TLR4). Remarkably, methylprednisolone increased the percentage of CD4+CD25+ Treg cells among CD4+ T cells in patients undergoing CPB, but did not increase the proportion of suppressive Treg cells, either resting or activated, in these patients undergoing CPB.

Conclusions:

Our results showed that prophylactic administration of methylprednisolone neither decreased the percentages and counts of inflammatory monocyte subsets nor did it induce the expansion of suppressive Treg cells in patients undergoing CPB. These results clarified the effects of GCs on cell-mediated immune responses and provided additional evidence in practice.

Trial registration:

Clinicaltrials.gov : NCT01296074. Registered 14 February 2011.
Bayesian Regression Model for Estimating Economic Loss Resulting from Two-Ship Collisions
Authors: Weng Jinxian , Liao Shiguan , Li Guorong
Published: January 2019

This study aims to develop a Bayesian regression model to evaluate the economic loss resulting from two-ship collisions using ten years’ ship collision data for occurrances in Fujian waters. The model results show that the involvement of passenger/cruise ships could cause the largest increment on economic loss in ship collisions. Interestingly, it is found the involvement of fishing ships could greatly increase the ship collision consequence in terms of economic loss. Results also reveal that the higher economic loss is associated with the collisions in the straits/sea areas, under the strong wind/wave conditions, during nighttime period, and in poor visibility conditions. The impact analysis results highlight that judgment errors play a decisive role in increasing the economic loss as compared with the other two types of human errors: lookout failure and operation errors. The results of this study are useful for policy-makers in proposing efficient strategies to mitigate the economic loss from two-ship collisions. The developed model is also beneficial for insurance companies in determining the appropriate ship insurance rates.
Risk Factors in Work Zone Safety Events: A Naturalistic Driving Study Analysis
Authors: Bharadwaj Nipjyoti , Edara Praveen , Sun Carlos
Published: January 2019

Identification of crash risk factors and enhancing safety at work zones is a major priority for transportation agencies. There is a critical need for collecting comprehensive data related to work zone safety. The naturalistic driving study (NDS) data offers a rare opportunity for a first-hand view of crashes and near-crashes (CNC) that occur in and around work zones. NDS includes information related to driver behavior and various non-driving related tasks performed while driving. Thus, the impact of driver behavior on crash risk along with infrastructure and traffic variables can be assessed. This study: (1) investigated risk factors associated with safety critical events occurring in a work zone; (2) developed a binary logistic regression model to estimate crash risk in work zones; and (3) quantified risk for different factors using matched case-control design and odds ratios (OR). The predictive ability of the model was evaluated by developing receiver operating characteristic curves for training and validation datasets. The results indicate that performing a non-driving related secondary task for more than 6 seconds increases the CNC risk by 5.46 times. Driver inattention was found to be the most critical behavioral factor contributing to CNC risk with an odds ratio of 29.06. In addition, traffic conditions corresponding to Level of Service (LOS) D exhibited the highest level of CNC risk in work zones. This study represents one of the first efforts to closely examine work zone events in the Transportation Research Board’s second Strategic Highway Research Program (SHRP 2) NDS data to better understand factors contributing to increased crash risk in work zones.
Modeling Construction Project-Induced Freight Reliability for South Carolina’s Interstate System
Authors: Siddiqui Chowdhury
Published: January 2019

This paper focuses on the freight component of the federal rulemaking for performance management that assesses freight travel time reliability on the interstate system. As this is the first time agencies (departments of transportations and metropolitan planning organizations) have been tasked with establishing targets for freight reliability (and other measures), the paper proposes a modeling approach to systematically account for the traffic and roadway characteristics and predict possible changes in the truck travel time reliability (TTTR) ratio due to construction projects. Although different trendlines can be utilized to provide a range of TTTR indices for future years, the subjective nature of predicting a target value in a future year demands a more systematic approach to capturing the effect of construction projects on the variability of the TTTR ratio. This study uses South Carolina’s interstate system to develop the two generalized linear models (GLMs) and a Bayesian GLM. Length and type of traffic message channel, type of construction project, area type, average annual daily traffic, and number of lanes were found to be among the significant predictors associated with a change in the TTTR ratio as a result of construction activity. This paper discusses the association of these causal factors and their influence on freight reliability. Owing to the contemporary nature of TTTR, there is no existing research predicting this particular type of freight reliability; as such, this work is thought to be relevant and beneficial for transportation engineers, planners and forecasters.
Synthesis, pyrolysis of a novel carborane ceramic precursor, and coating on carbon fiber
Authors: Zong Yakun , Tong Dejin , Li Zhanxiong
Published: January 2019

A novel carborane–carbosilane–(cyclo-silazane) polymer has been synthesized as precursor of ceramic and applied to the surface treatment of carbon fiber (Cf) by precursor infiltration and pyrolysis method. The preparation of carborane precursor was carried out by hydrosilylation of trivinyltrimethylcyclosilazane with dimethylchlorosilane firstly, and then by polycondensation reaction with hydroxylated 1,1′-hydroxysilylene-2,2′-bis(hydroxydimethylsilyl)biscarborane whose −OH was formed by transferring the newly introduced C–H bond via hydroxylation. Chemical structure of the polymer was studied by liquid-nuclear magnetic resonance while evolution of various ceramic phases was studied by Fourier transform infrared spectroscopy and the thermal curing process was studied by thermogravimetric/differential thermal analysis and pyrolysis-gas chromatography/mass spectrometry. The cross-linked polyborosilazane precursor exhibited higher ceramic yield of 65.6% at 1000°C. The coating on the Cf was identified to be uniform, relatively smooth, and continuous with a thickness ranged from 0.1 to 0.5 μm through scanning electron microscope and energy dispersive spectroscopy. Thermogravimetric analysis revealed high temperature stability of the coated Cf in flowing air up to 600°C.
Flight dynamics modeling of elastic aircraft using signal decomposition methods
Authors: Amin Bagherzadeh Seyed
Published: January 2019

To improve the precision and accuracy of the flight dynamic models for elastic aircraft, this paper provides a novel method that extracts observable flight modes from flight test data and uses them in the identification process. For this purpose, a gray-box time-domain method is employed with the nonlinear ARX structure and the Levenberg–Marquardt parameter estimation technique. In the proposed method, the components of the flight parameters are extracted by two signal decomposition techniques, namely the singular spectrum analysis and empirical mode decomposition. These components are inputted into the identification process. Flight test data of the active aeroelastic wing is examined by the proposed method. The results indicate that both the singular spectrum analysis-based and empirical mode decomposition-based identification processes have desired performances in dealing with nontrained flight conditions. Thus, these methods may be utilized as an interpolation method to estimate the aircraft flight dynamics within the flight envelope. However, the empirical mode decomposition outperforms the singular mode decomposition because it is more significant in decomposing flight parameters based on the frequency content. Hence, the empirical mode decomposition may be a better tool to be employed for the aeroelastic aircraft system identification.
An investigation of a high-speed ground manoeuvre under optimal control
Authors: Huang Zexin , Best Matthew , Knowles James
Published: January 2019

This paper studies the behaviour of a nonlinear aircraft model under optimal control for aircraft ground manoeuvres, specifically for high-speed runway exits. The aircraft's behaviour on the ground is captured by a fully parameterised 6-DOF nonlinear model, which is developed in this work to model the effects of braking through a combined slip tyre model. A pre-defined cost function is minimised using a generalised optimal control algorithm to obtain an optimal control sequence for a particular manoeuvre-cost function combination. In this paper, three scenarios are investigated for a 45-degree high-speed runway exit: the first control sequence minimises the distance between the aircraft's centre of gravity and the runway centreline; the second maximises the distance travelled by the aircraft during the 20 s of simulation time; the third minimises tyre wear. For each scenario, the generalised optimal control algorithm provides the best possible control inputs. The dynamic response of the aircraft throughout the turn is shown to be dominated by its inertia, which suggests that future controllers will need to begin executing a turn far in advance of entering the corner. The results also provide a benchmark against which the effectiveness of future real-time controllers may be judged.
IFRSs Convergence and Expectation Gap: Vindication from Practitioners
Authors: Deb Rajat , Das Joydeep
Published: January 2019

The study has attempted to measure the Indian practitioners’ expectation gaps about IFRSs convergence. Based on literature, two hypotheses, a conceptual model and a questionnaire, have been formed. Through protocol interviews followed by a pretest, the questionnaire has been tested (reliability and validity) before conducting the online survey. A total of 159 sample responses has been assessed to measure the gaps on four major parameters. For assaying the gaps, the arithmetic and weighted arithmetic mean differences and paired sample t-test have been applied, which have indicated the likely persistence of gaps. The significant statistical results have indicated likely to reject the null hypotheses and it has to conclude that regulatory requirements have influenced in convergence and the Ind AS probably to improve the reporting practices, audit qualities and analysts’ forecasting. Study limitations, practical implications and roadmap for further research have also been indicated.
Methods and Challenges in a Cohort Study of Infants and Toddlers With Craniofacial Microsomia: The Clock Study
Authors: Luquetti Daniela V. , Speltz Matthew L. , Wallace Erin R. , Siebold Babette , Collett Brent R. , Drake Amelia F. , Johns Alexis L. , Kapp-Simon Kathleen A. , Kinter Sara L. , Leroux Brian G. , Magee Leanne , Norton Susan , Sie Kathleen , Heike Carrie L.
Published: January 2019

Objective:

The Craniofacial microsomia: Longitudinal Outcomes in Children pre-Kindergarten (CLOCK) study is a longitudinal cohort study of neurobehavioral outcomes in infants and toddlers with craniofacial microsomia (CFM). In this article, we review the data collection and methods used to characterize this complex condition and describe the demographic and clinical characteristics of the cohort.

Setting:

Craniofacial and otolaryngology clinics at 5 study sites.

Participants:

Infants with CFM and unaffected infants (controls) ages 12 to 24 months were recruited from the same geographical regions and followed to age 36 to 48 months.

Methods:

Phenotypic, neurodevelopmental, and facial expression assessments were completed during the first and third waves of data collection (time 1 and time 3, respectively). Medical history data were taken at both of these time points and during an intermediate parent phone interview (time 2).

Results:

Our cohort includes 108 cases and 84 controls. Most cases and controls identified as white and 55% of cases and 37% of controls identified as Hispanic. Nearly all cases had microtia (95%) and 59% had mandibular hypoplasia. Cases received extensive clinical care in infancy, with 59% receiving care in a craniofacial clinic and 28% experiencing at least one surgery. Study visits were completed at a study site (92%) or at the participant’s home (8%).

Conclusions:

The CLOCK study represents an effort to overcome the challenges of characterizing the phenotypic and neurodevelopmental outcomes of CFM in a large, demographically and geographically diverse cohort.
Factors Associated with Parental Treatment Attitudes and Information-Seeking Behaviors for Childhood ADHD
Authors: Taylor Lea E. , Antshel Kevin M.
Published: January 2019

Objective: Despite the association between childhood ADHD and long-term negative outcomes, there is a significant delay to treatment and a low rate of lifetime treatment contact for individuals with ADHD. Method: The current study examined (a) variables associated with parental treatment-seeking attitudes and information-seeking behaviors and (b) the relationship between these attitudes and behaviors in 87 non–treatment-seeking parents whose children had elevated ADHD symptoms. Results: Regressions indicated that attitudes toward ADHD treatment were associated with ADHD knowledge and misconceptions ( ps < .01), susceptibility to ADHD stigma ( p < .001), and satisfaction with past providers ( ps < .01). Experience with past providers was significantly associated with information-seeking behavior ( ps < .01). Conclusion: Parental knowledge of ADHD, low levels of stigma, and positive experiences with past providers were the strongest predictors of positive attitudes about ADHD treatment. Experience with past providers was the only factor related to treatment-seeking behavior. These results offer avenues to decreasing barriers to treatment in pediatric ADHD.
Programmed Death-ligand 1 Expression With Clone 22C3 in Non-small Cell Lung Cancer: A Single Institution Experience
Authors: Takeda Maiko , Kasai Takahiko , Naito Maiko , Tamiya Akihiro , Taniguchi Yoshihiko , Saijo Nobuhiko , Naoki Yoko , Okishio Kyoichi , Shimizu Shigeki , Kojima Kensuke , Nagoya Akihiro , Sakamoto Tetsuki , Utsumi Tomoki , Yoon Hyung-Eun , Matsumura Akihide , Atagi Shinji
Published: January 2019

Background:

In recent years, the anti-programmed cell death 1 (PD-1) drug pembrolizumab (Keytruda) was approved for treatment of unresectable advanced non-small cell lung cancer (NSCLC) as first- or second-line therapy depending on the clone 22C3-programmed death-ligand 1 (PD-L1) immunohistochemical expression score by the companion diagnostic assay. We herein evaluated 22C3-PD-L1 expression of NSCLC in a single institution experience and compared it with clinicopathologic features.

Materials and methods:

We assessed 22C3-PD-L1 expressions of 411 patients with NSCLC from our institution, including in past specimens. Programmed death-ligand 1 immunohistochemistry (IHC) testing was performed using the PD-L1 clone 22C3 pharmDx kit (Agilent Technologies/Dako, Carpinteria, CA, USA). Patients were separated into 3 groups with <1% (no expression), 1% to 49% (low expression), or ⩾50% (high expression) positive tumor cells.

Results:

In all, 137 patients (33%) did not express PD-L1, 155 (38%) showed low expression, and 119 (29%) demonstrated high expression. Archival samples showed lower PD-L1 expression than that of recent samples, and the ratios of no expression case significantly increased by using paraffin blocks embedded particularly in more than 4 years ago. Programmed death-ligand 1 positivity was significantly associated with male sex, smoking, higher tumor grade, squamous cell carcinoma in histologic type, wild-type EGFR, and ALK rearrangement positive.

Conclusions:

The rate of 22C3-PD-L1 expression of NSCLC detected in this study was similar to the frequencies of the previous reports, although the ratio of expression case decreased when using old paraffin blocks.
The living experience of losing genetic continuity: Concealment tendency in Chinese recipients of donor-assisted conception
Authors: Tsui Elaine Yin-Ling , Cheng Joanna Oi Yue
Published: January 2019

This study explored how Chinese women with donor-assisted conception experienced loss of genetic continuity and managed donor-assisted conception–related information. Through Interpretative Phenomenological Analysis, a thematic framework on women’s beliefs, motivation, and behaviors in information management was constructed. Contrary to the Western trend toward disclosure, it was found that Chinese women strongly preferred to conceal, in order to protect their family members, the parent–child relationship, and family stability. Participants’ strong preference was also indicated in specific behaviors that ensure information concealment. The findings of this study may contribute toward the development of culturally sensitive clinical guidelines for counseling practice that supports infertile couples’ decision-making.
A complement to period/frequency estimation of a nonlinear oscillator
Authors: He Chun-Hui , Wang Jian-Hong , Yao Shao-wen
Published: January 2019

A fast estimation of periodic properties of a nonlinear oscillator is much needed as pointed out by Tian and Liu in their review article (Tian D and Liu Z, Journal of Low Frequency Noise, Vibration & Active Control, https://doi.org/10.1177/1461348418756013 ). Although a relatively high accuracy can be achieved, there is no way to continue the solution process to obtain any accuracy of a solution. This paper suggests an effective modification so that any accurate frequency can be obtained.
Design and experimental development of a new electronically controlled cylinder lubrication system for the large two-stroke crosshead diesel engines
Authors: He Yuhai , Zhou Peilin , Xie Liangtao , Zhang Jiyun
Published: January 2019

Accurate, stable and reliable lubrication for the cylinders is very important to ensure the trouble-free operation of the marine diesel engines. A new electronically controlled cylinder lubrication system has been developed to remedy the defects of the conventional mechanical lubrication system. This new system’s design method, composition and implementation are described. The sensitivity tests are conducted on the test bench and the verification tests are also fulfilled on operating vessels. The main performance data are as follows: oil injection pressure about 3.0 MPa, oil injection timing precision 0.1 ms, oil injection duration 15 °CA or less. The oil injection concentrates onto the piston rings pack to ensure the good lubrication and neutralization, and the oil injection frequency is regulated according to engine load, the sulphur content in fuel, total base number of cylinder oil, cylinder liner running-in condition and so on. This results in the cylinder oil consumption rate falling approximately 25% compared with that of the conventional mechanical lubrication system. As a retrofit on vessels in service, the lubrication system has been fitted more than 120 main engines and has a payback period of less than 2 years.
Public pedagogies of edible verge gardens: Cultivating streetscapes of care
Authors: Hsu Jesse P
Published: January 2019

Edible verge gardens, which are cultivated sections of public footpaths created by residents for household and community use, have gradually become more common in some Australian cities. As an emergent form of urban agriculture, verge gardens uniquely provide opportunities for encountering and learning about food cultivation and consumption practices at the mundane level of the footpath. The “public pedagogy” potentially generated by the spaces can be conceptualized as not only a range of garden-oriented learning experiences but also an incremental journey of embedding into the daily life of the neighborhood. Considering this 'pedagogical life' enables understanding of the extent to which specific urban agricuture spaces mediate care, or the interdependence between all human and non-human life, in the function-oriented spaces of the city. To this end, I explore the interplay of semiotic and performative aspects of verge gardens through multimodal discourse analysis and ethnographic methods, respectively, to understand both the material affordances present in and through the spaces as well as the subsequent “post-launch” life of the gardens. This 'multimodal-performative' approach allows for a micro-scale understanding of how urban agriculture spaces potentially re-educate public sensibilities around food and reimagine the city in terms of care—a visible integration of food, community, and urban space. The analysis elucidates the mundane yet consequential process of urban agriculture spaces folding into the everyday rhythms of neighborhood life. This research suggests that the ethics of everyday food practices (i.e. cultivation, procurement, preparation, eating, etc.) and the ethics of space are intimately related.
Governing and commercialising early childhood education: Profiting from The International Early Learning and Well-being Study (IELS)?
Authors: Roberts-Holmes Guy
Published: January 2019

This article examines why the government in England has signed the country up to taking part in the OECD’s new international assessment known as The International Early Learning and Well-being Study (IELS). The article highlights the role of IELS as a technology of neoliberal governance. Looking forward it considers how IELS may open up new business opportunities and spaces for profit for businesses in England and elsewhere. At present, IELS is a fledgling product, but it may in time further add to the explanatory and governing power of the OECD to steer national policy makers towards a homogenised educational future defined by the organisation. IELS is run and managed by the National Foundation for Education Research (NFER), a national not-for-profit research organisation. The article explores how this same not-for-profit organisation also won the remarkably similar early childhood English Baseline Assessment 2 worth £9.8 million. Finally, the article examines the possibility that, in the future, if IELS were to develop, the edu-business Pearson might be interested in IELS to add to its existing interests in global data governance for profit.
Gformula: Estimating Causal Effects in the Presence of Time-Varying Confounding or Mediation using the G-Computation Formula
Authors: Daniel Rhian M. , De Stavola Bianca L. , Cousens Simon N.
Published: January 2019

This article describes a new command, gformula, that is an implementation of the g-computation procedure. It is used to estimate the causal effect of time-varying exposures on an outcome in the presence of time-varying confounders that are themselves also affected by the exposures. The procedure also addresses the related problem of estimating direct and indirect effects when the causal effect of the exposures on an outcome is mediated by intermediate variables, and in particular when confounders of the mediator–outcome relationships are themselves affected by the exposures. A brief overview of the theory and a description of the command and its options are given, and illustrations using two simulated examples are provided.
Prospective Randomized Trial Comparing HAL-RAR Versus Excisional Hemorrhoidectomy: Postoperative Pain, Clinical Outcomes, and Quality of Life
Authors: Carvajal López Fernando , Hoyuela Alonso Carlos , Juvany Gómez Montserrat , Troyano Escribano Daniel , Trias Bisbal Miguel Angel , Martrat Macià Antoni , Ardid Brito Jordi
Published: January 2019

Purpose. To compare outcomes of hemorrhoid artery ligation with recto-anal repair (HAL-RAR) and excisional hemorrhoidectomy (EH). The primary objective was to compare postoperative pain, and the secondary objectives were the following: symptom resolution rates, postoperative morbidity, recurrence, and changes in quality of life. Method. Prospective randomized controlled trial, including 40 patients with grades III-IV hemorrhoids who were allocated 1:1 to HAL-RAR and EH. Follow-up evaluation was performed at 15 days, 30 days, 6 months, 12 months, and then annually. Pain was measured using a Visual Analogic Scale and was self-recorded by patients. Quality of life was measured with Short Form Survey-36 questionnaire. Results. Postoperative pain was lower in the HAL-RAR group during the first 30 postoperative days. Moreover, from day 7 onward more patients in the HAL-RAR group reported complete absence of pain (Visual Analogic Scale score = 0). Globally, symptom resolution was significantly higher ( P = .03) in the HAL-RAR group at day 15. Bleeding resolution was observed earlier in the HAL-RAR group than in the EH group ( P = .04), but no differences in the resolution of prolapse, itching, and soiling were observed during the 30-day follow-up. After a mean follow-up of 15 months (range 12-27 months), no differences in postoperative morbidity and no recurrences were observed. An improvement was observed in all sections evaluated by the Short Form Survey-36 questionnaire with both techniques. Conclusion. HAL-RAR provokes less postoperative pain during a shorter period than EH and achieves resolution of hemorrhoidal symptoms with less postoperative complaints. No differences in morbidity and recurrence rate were observed after 12 months of follow-up.
Expressed emotions and experiences from relatives regarding having a family member living in a nursing home for older people
Authors: Dorell Åsa , Sundin Karin
Published: January 2019

Objectives:

The purpose of this study was to describe the topics relatives with a family member in a nursing home for older persons choose to talk about and focus on when participating in a nurse-led “Family Health Conversations” intervention. Family Health Conversations consisted of a series of three nurse-led conversations with each family, with a 2-week interval between meetings.

Methods:

The Family Health Conversations meetings were tape-recorded and analyzed using qualitative content methods. The participants were relatives of family members living in a nursing home for older persons in a municipality in Sweden.

Results:

The findings showed how the relatives talked about their suffering and difficulties concerning the new situation. The relatives talked about frustration and sadness together in a new way, with a focus on how to manage the future. They also wished that they had been offered an opportunity to talk about this with nurses earlier in the illness trajectory.

Conclusion:

The relatives had a significant need to talk about their experiences together within the family and together with the nurses. Nurses have an especially important task in supporting relatives having a family member living in a nursing home.
Idiopathic Acute Mitral Regurgitation Due to Chordal Rupture in Infants: Surgical Management and Results
Authors: Yoshizawa Kosuke , Fujiwara Keiichi , Ohno Nobuhisa , Watanabe Kentaro , Sakazaki Hisanori
Published: January 2019

Objective:

Emergency surgical treatment is required for idiopathic acute mitral regurgitation due to chordae rupture in infants. Nevertheless, mitral valve repair for such a patient population still remains challenging. We report our experience with mitral valve repair for idiopathic acute mitral regurgitation due to chordae rupture in infants.

Methods:

From 2005 to 2017, six infants (four boys) were diagnosed with acute mitral regurgitation due to chordae rupture and underwent mitral valve repair. The median age, mean body weight, and median follow-up period were 5.5 months (range: 4-9 months), 6.8 kg (range: 5.5-8.0 kg), and 6.4 years (range: 6 months to 10 years), respectively.

Results:

In all cases, surgical intervention was performed within 24 hours of admission. Artificial chordae reconstruction and paracommissural edge-to-edge repair were utilized in three and four cases, respectively, while Kay’s annuloplasty was performed in all cases. Mean cardiopulmonary bypass time and aortic cross-clamp time were 117 minutes (range: 70-143 minutes) and 73 minutes (range: 35-108 minutes), respectively. No early or late deaths and reoperations had occurred during the follow-up period. Moreover, postoperative mitral regurgitation was significantly reduced, while no chronologic progression of mitral regurgitation was observed.

Conclusions:

The combination of various techniques, such as artificial chordae reconstruction, paracomissural edge-to-edge repair, and Kay’s annuloplasty, can be a promising surgical option for idiopathic acute mitral regurgitation due to chordae rupture in infants.
Risk Factors and Outcome of Post Fallot Repair Junctional Ectopic Tachycardia (JET)
Authors: Paluszek Corinna , Brenner Paolo , Pichlmaier Maximilian , Haas Nikolaus A. , Dalla-Pozza Robert , Hagl Christian , Hakami Lale
Published: January 2019

Background:

Junctional ectopic tachycardia (JET) is a common arrhythmia causing hemodynamic impairment following corrective cardiac surgery such as tetralogy of Fallot (TOF) repair.

Methods:

We report our experience with postoperative JET following surgical repair of TOF. The retrospective study was done from 2003 to 2012 with a total of 105 patients who underwent TOF repair. These patients’ clinical and electrocardiographic data (pre-, intra-, and postoperative) were monitored to identify risk factors for the occurrence of JET and to evaluate the outcome of the affected patients.

Results:

Incidence—Fourteen patients developed JET, with only four patients going directly from sinus rhythm to JET. In all others, either a transient atrioventricular (AV) block or a junctional rhythm preceded JET, mostly intraoperatively, showing a significant relation ( P = .010). Age—Patients with JET were of younger age ( P = .025) and had longer cardiopulmonary bypass ( P = .044) and aortic cross-clamping times ( P = .038). Increased cost and care—The occurrence of JET was associated with a longer stay in the intensive care unit (ICU) and a prolonged need for inotropic support and mechanical ventilation. Time to rate control correlated with length of ICU and hospital stay.

Mortality:

All JET patients converted into sinus rhythm, one of them died shortly after cessation of JET and two patients subsequently developed a first-degree AV block.

Conclusion:

The occurrence of JET remains an important complication during the initial postoperative period by increasing mechanical ventilation time, the need for inotropic support, and prolonging the length of ICU and hospital stay. Risk factors are younger age, longer aortic cross-clamping/bypass times, and intraoperative arrhythmias.
Association between endometriosis, headache, and migraine
Authors: Karamustafaoglu Balci Burcin , Kabakci Zehra , Guzey Damla Y , Avci Bartu , Guler Murathan , Attar Erkut
Published: January 2019

Introduction:

Available data suggest that there is an association between endometriosis and a group of disorders including autonomic nervous system irregularities. A deeper understanding of relationship between endometriosis and autonomic nervous system is needed as it may lead to novel discoveries on the causes or consequences of endometriosis. In this study, we analyzed the prevalence of migraine in patients with endometriosis.

Methods:

In this cross-sectional study, medical records of women were reviewed through January 2013 to December 2017. Women with laparoscopically proven endometriosis (n = 185) were compared with those without endometriosis (n = 168). The 3-item screening questions (ID Migraine™) test was used to screen migraine. Data were analyzed using SPSS v25 (IBM Corporation). The χ2 test was used for analyzing the nominal parameters and group comparisons. Pearson χ2 was used to study the association between endometriosis and migraine.

Results:

The mean age was 31.86 ± 4.49 years of the endometriosis group and 28.95 ± 5.11 years of the controls (p = 0.408). The two pre-screening questions of ID Migraine test were answered positively by 86 patients of the endometriosis group (75.4%) and by 53 patients of the control group (54.6%) (p = 0.001). Of these patients, 51 (44.7% of endometriosis group) and 26 (26.8% of control group) were diagnosed as having migraine using 3-item Migraine questionnaire (p = 0.007).

Conclusion:

This study showed that the prevalence of migraine was significantly higher in patients with endometriosis. Because there is a strong correlation, patients with endometriosis should be screened for headache and migraine to increase the benefits of care.
The effects of a single carbon dioxide and hot water hand bath on acral perfusion in systemic sclerosis: A randomized, clinical study
Authors: Lange Uwe , Bogensperger Stephanie , Tarner Ingo H , Müller-Ladner Ulf
Published: January 2019

Secondary Raynaud’s phenomenon is the most common manifestation of systemic sclerosis, affecting more than 99% of systemic sclerosis patients, and a major cause of morbidity. Frequent and prolonged secondary Raynaud’s phenomenon attacks not only cause severe discomfort and pain but also ischemic acral tissue damage. In addition to vasoactive drugs, carbon dioxide (CO2) hand bath and hot water bath are potential non-pharmacological treatment options which can be self-administered by affected patients at any time. In order to compare the efficacy of these two physical measures, this randomized, clinical study evaluated the effects of a single CO2 hand bath in patients with systemic sclerosis and secondary Raynaud’s phenomenon and a healthy control group versus a single hot water hand bath on acral perfusion in systemic sclerosis by Doppler ultrasonography. None of the patients had currently digital ulcers, a vasoactive medication or a concomitant vascular disease. CO2 immersion induced an acute hemodynamic response, whereas hot water immersion had no significant effect on acral perfusion in systemic sclerosis.
Using Machine Learning to Predict Lower-Extremity Injury in US Special Forces
Authors: CONNABOY CHRIS , EAGLE SHAWN R. , JOHNSON CALEB D. , FLANAGAN SHAWN D. , MI QI , NINDL BRADLEY C.
Published: January 2019

Introduction

Musculoskeletal injury rates in military personnel remain unacceptably high. Application of machine learning algorithms could be useful in multivariate models to predict injury in this population. The purpose of this study was to investigate if interaction between individual predictors, using a decision tree model, could be used to develop a population-specific algorithm of lower-extremity injury (LEI) risk.

Methods

One hundred forty Air Force Special Forces Operators (27.4 ± 5.0 yr, 177.6 ± 5.8 cm, 83.8 ± 8.4 kg) volunteered for this prospective cohort study. Baseline testing included body composition, isokinetic strength, flexibility, aerobic/anaerobic capacity, anaerobic power, and landing biomechanics. To evaluate unilateral landing patterns, subjects jumped off two-feet from a distance (40% of their height) over a hurdle and landing single-legged on a force plate. Medical chart reviews were conducted 365 d postbaseline. χ2 automatic interaction detection (CHAID) was used, which compares predictor variables to LEI and assigns a population-specific “cut-point” for the most relevant predictors.

Results

Twenty-seven percent of operators (n = 38) suffered LEI. A maximum knee flexion angle difference of 25.1% had the highest association with injury in this population (P = 0.006). Operators with >25.1% differences in max knee flexion angle (n = 13) suffered LEI at a 69.2% rate. Seven of the 13 Operators with >25.1% difference in max knee flexion angle weighed >81.8 kg, and 100% of those operators suffered LEI (P = 0.047; n = 7). Only 33% of operators with >25.1% difference in max knee flexion angle that weighed <81.8 kg suffered LEI.

Conclusions

This study demonstrated increased risk of LEI over a 365-d period in Operators with greater differences in single-leg landing strategies and higher body mass. The CHAID approach can be a powerful tool to analyze population-specific risk factors for injury, along with how those factors may interact to enhance risk.
No Thermoregulatory Impairment in Skin Graft Donor Sites during Exercise-Heat Stress
Authors: CRAMER MATTHEW N. , MORALEZ GILBERT , HUANG MU , CRANDALL CRAIG G.
Published: January 2019

The US Army’s Standards of Medical Fitness, AR 40-501, state that “Prior burn injury (to include donor sites) involving a total body surface area of 40% or more does not meet the standard.” Inclusion of donor sites (sites harvested for skin grafts) in this standard implies that thermoregulatory function is impaired within donor sites during exercise-heat stress; however, supporting evidence is currently lacking.

Purpose

To test the hypothesis that well-healed donor and noninjured sites demonstrate similar elevations in skin blood flow and sweating during exercise-induced hyperthermia.

Methods

Twenty burn survivors (>1 yr postinjury; four females) cycled for 60 min in a 39.7°C ± 0.3°C and 21.1% ± 3.3% relative humidity environment at approximately 50% of maximal aerobic capacity. Core and mean skin temperatures were recorded throughout exercise. Skin blood flow (laser-Doppler imaging) was measured at baseline and after exercise within donor (LDFDON) and adjacent noninjured control (LDFCON) sites. At 45 min of exercise, local sweat rates (Technical Absorbents) were measured within the same donor (LSRDON) and noninjured (LSRCON) areas.

Results

After 60 min of exercise, core and skin temperatures reached 38.2°C ± 0.4°C and 35.5°C ± 1.2°C, respectively. The increase in skin blood flow from baseline to end-exercise (LDFDON, 91.6 ± 44.5 AU; LDFCON, 106.0 ± 61.6 AU; P = 0.17) and local sweat rates (LSRDON, 0.46 ± 0.26 mg·cm−2·min−1; LSRCON, 0.53 ± 0.25 mg·cm−2·min−1; P = 0.14) were not different between donor and noninjured control sites.

Conclusions

Well-healed donor sites retain the ability to increase skin blood flow and sweating during exercise heat stress, providing evidence against the inclusion of donor sites when determining whether a burn injury meets the Army’s Standards of Medical Fitness.
Teacher Pay and Student Performance: Evidence from Brazil
Authors: Tavares Priscilla , Ponczek Vladimir
Published: January 2019

In this paper, we provide evidence of the effects of teacher’s pay increases on students’ learning in the context of developing countries (São Paulo state public education). We explore the variation in teachers' pay, given by the rule of additional salaries by length of service (quinquennium rule). We observed each teacher's eligibility for salary increases and explored the differences in the teachers’ admission date throughout the year to calculate the exposure time of teachers treated at higher salaries. We employ a difference-in-differences strategy to control for unobserved characteristics of teachers belonging to different admission cohorts. Our results are in line with what is found in the international empirical literature: salary increases for incumbent teachers do not seem to affect their productivity and, therefore, are not capable of impacting student learning in basic education.
Multivariate Spatial IV Regression
Authors: Nascimento Marcus Gerardus Lavagnole , Abanto-Valle Carlos Antonio , Mendonça Mario Jorge
Published: January 2019

In this paper, a Multivariate Spatial Regression model with Endogenous Variables is proposed. In order to deal with endogeneity and spatial dependence, the instrumental variables (IV) methodology and an autoregressive spatial structure, frequently used in econometric applications, are implemented. A Bayesian inference procedure based on simulation schemes designed to obtain samples from the posterior distribution of model parameters is developed. Finally, the methodology is illustrated through an application to the impact of broadband access on the economic sectors.
Financial Aid and Student Performance in College: Evidence from Brazil
Authors: Lepine Andrea
Published: January 2019

This paper studies the effects of a government scholarship program for low-income college students in Brazil, the Prouni. In order to deal with selection effects, I use propensity score matching based on observable student characteristics and a proxy for previous student performance. The results are robust across different specifications, and suggest that students who received a scholarship perform better than comparable students and take less time to reach the final year of college. These effects are higher for students with full scholarships than for students with partial scholarships, and seem to be partially driven by a decrease in the proportion of students who work and an increase in time spent studying.
Assessment for Ecological Condition of Volga and Don Reservoirs by Bio-Indication Method
Authors: Косолапов Д. , Kosolapov D. , Девисилов Владимир , Devisilov Vladimir , Новиков Д. , Novikov D. , Черемушкина О. , Cheremushkina O.
Published: January 2019

Within a framework of field researches was carried out a water sampling for definition of hydro-biological indicators for the purpose of Volga reservoirs’ ecological state and water quality assessment. On the basis of bio-indicators (such as heterotrophic bacterial plankton and zooplankton) the Volga reservoirs’ condition was defined. The research methods and results, as well as stations for sampling have been presented, quality and quantitative indices of aquatic organisms have been defined, and assessment of reservoirs’ nutritional status, ecological state and water quality has been carried out. Based on carried out researches has been drawn a conclusion on the need of urgent measures for improvement of Volga and numerous Volga reservoirs’ ecological condition.
Increasing of Power Oil-Filled Transformers’ Operation Reliability and Safety
Authors: Баширов М. , Bashirov Mussa , Хисматуллин Азат , Hismatullin Azat , Прахов И. , Prahov I.
Published: January 2019

This paper is devoted to the currently urgent problem — increasing reliability and safety for power oil transformers’ operation with considerable long and short overloads through cooling systems’ efficiency upgrading, allowing increase the power oil transformers’ operation safety, engine life, reliability and economical efficiency. Statistical data on fault causes for transformers of different voltage classes and lifecycles have been given. Based on the study of statistical data it has been established that one of the main causes for transformers faults was the inefficiency of oil cooling systems during the summer period of operation and with considerable long and short overloads. For improvement of efficiency of power oil transformers’ cooling system the agitation of cooling oil by circulating sulfur hexafluoride (SF6) and subsequent sulfur hexafluoride cooling with a thermoelectric cooler is proposed. The system of sulfur hexafluoride circulation and cooling switches on automatically at considerable long and short overloads. The design and operation of the proposed cooling system for oil transformers have been considered. A series of laboratory experiments for transformer oil cooling in a power transformer’s tank without and with a compressor has been carried out. Graphs of temperature-time relationship at natural cooling and when using agitation have been presented. The coefficients of transformer oil’s thermal diffusivity and heat transfer at various distances from heating element have been experimentally defined. The mathematical problem of a heat flux distribution in a rectangular parallelepiped has been considered, a solution for thermal conductivity equation in the power transformer’s tank, which is a rectangular parallelepiped, has been presented. A laboratory setup design has been described in detail. Brands of used thermocouples, compressor and analog-digital converter have been presented. Use of the upgraded cooling system will allow increase the transformers operation safety and reliability.