bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation on the discharge energy storage density of the Rb substituted Na0.5Bi0.5TiO3 relaxor ferroelectric and its suitability for the orthopedic application
Authors: Banerjee Krishnarjun , Alvi Syed Baseeruddin , Rengan Aravind Kumar , Asthana Saket
Published: May 2019

The higher hardness along with the excellent dielectric and ferroelectric properties of the ferroelectric material is always required for its direct application. In spite of that, in comparison to the ferroelectric and piezoelectric properties, the study of the hardness property of the ferroelectric materials is almost deprived. Herein, we had showed the improvement in the hardness and relaxor property of the Rb substituted Na0.5Bi0.5TiO3 (NBT) with the variation of the grain size. The emergence of the polar nano region, which is responsible for the relaxor behavior, was verified with the addition of Rb (or with the reduction of the grain size). This interesting behavior was explained through the temperature dependent “order parameter” of all compositions. The reduced coercive field helped to enhance the discharge energy storage density up to 0.71 J/cm3 for the 4 mole % Rb substituted NBT. The same composition had the hardness of 11.75 GPa, which showed its excellent resistance to the abrasion. These outcomes showed the possibility of the current material to replace the lead based piezoceramics. Moreover, to utilize this material as an orthopedic implant, its biocompatibility was assessed in vitro. As an advantage, by using the current lead free piezoelectric material as an implant, the failure of the implant can be evaluated noninvasively.
Poor management of hypertension is an important precipitating factor for the development of acute aortic dissection
Authors: Dong Ning , Piao Hulin , Li Bo , Xu Jian , Wei Shibo , Liu Kexiang
Published: May 2019

Hypertension is considered a key risk factor for acute aortic dissection (AAD). However, there is limited evidence demonstrating if hypertension management affects AAD development. The objective of this study was to investigate the role of hypertension management in AAD development in a Chinese population. A total of 825 AAD patients and 3300 age‐ and sex‐matched controls were included. The authors analyzed data on demographics, chronic comorbidities, and hypertension management of all participants. Multiple logistic regression analysis was used to estimate the adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) for the relationship between chronic comorbidities, as well as the management of hypertension and AAD risk. After adjusting for other related factors, multivariate logistic regression identified hypertension, chronic kidney disease, Marfan syndrome, history of cardiovascular surgery, and history of smoking as risk factors for AAD. Among the identified risk factors, hypertension was an important and controllable risk factor for AAD development. Thus, the authors further evaluated how hypertension management affects AAD development. A total of 848 controls and 585 AAD patients with hypertension were enrolled in this part of the study. Hypertensive patients with AAD had a longer history, higher stage, poorer medication compliance, and poor control rates of blood pressure, among which poor medication compliance (Irregular vs Regular P < 0.001; Never treated vs Regular P < 0.001) and uncontrolled hypertension (P < 0.001) significantly increased the risk of AAD development. In conclusion, uncontrolled hypertension and poor medication compliance are important precipitating and controllable factors for AAD development.
Anxiety in the family: a genetically informed analysis of transactional associations between mother, father and child anxiety symptoms
Authors: Ahmadzadeh Yasmin I. , Eley Thalia C. , Leve Leslie D. , Shaw Daniel S. , Natsuaki Misaki N. , Reiss David , Neiderhiser Jenae M. , McAdams Tom A.
Published: May 2019

Background

Anxiety in parents is associated with anxiety in offspring, although little is known about the mechanisms underpinning these intergenerational associations. We conducted the first genetically sensitive study to simultaneously examine the effects of mother, father and child anxiety symptoms on each other over time.

Method

Adoptive parent and child symptoms were measured at child ages 6, 7 and 8 years from 305 families involved in the Early Growth and Development Study, using a prospective adoption design. Children were adopted at birth to nonrelatives, and composite data on internalising problems within birth families were used as a proxy measure of offspring inherited risk for anxiety. Structural equation models were fitted to the data to examine prospective associations between adoptive mother, father and child symptoms, whilst accounting for individuals’ symptom stability over time.

Results

Child anxiety symptoms at age 7 predicted adoptive mothers’ anxiety symptoms at age 8. No mother‐to‐child or child‐to‐father effects were observed. These results were consistent in sensitivity analyses using only paternal offspring reports and using a second measure of child anxiety symptoms. Fathers’ anxiety symptoms at child age 6 prospectively predicted child symptoms, but only when paternal offspring reports were included in the model. Composite data on birth family internalising problems were not associated with child anxiety symptoms.

Conclusions

Results show environmentally mediated associations between parent and child anxiety symptoms. Results support developmental theories suggesting that child anxiety symptoms can exert influence on caregivers, and mothers and fathers may play unique roles during the development of child symptoms. Further research is needed on the role of genetic transmission associated with anxiety symptoms in biologically related families. In the meantime, researchers and clinicians should strive to include fathers in assessments and consider the effects of child symptoms on caregivers.
The Myth of the Cave and the experience of illness
Authors: Mitchell Derek
Published: May 2019

In this paper, I will consider, from a number of philosophical and real‐life perspectives, what happens to us when we fall ill and what the experience of falling ill tells us about the nature of our being. I will take up the oft used Myth of the Cave from Plato's Republic and use this as a means to interpret the experience of falling ill. Plato gave us the allegory to show that what we think we know might not be all there is to know and that what we take for truth may not, at least, be the whole truth. I will argue that The Myth of the Cave provides an allegorical basis for coming to understand ourselves as finite and mortal through the experience of illness. We emerge from the dark safety of our everyday lives into the world of illness; this brings us up short as we come face to face with our own mortality. To make the argument, I will use examples from my own experience of illness and some of those other which have been recounted to me. I will also refer to the work of Havi Carel on illness and mortality, the conception of illness as leading to a feeling of not‐being‐at‐home with our bodies (unheimlich) discussed by Frederick Svenaeus, and Gadamer's notion of illness as a loss of equilibrium. Underpinning the argument throughout will be Heidegger's existential analysis of dying in which he discusses the experience of anxiety and the way that separates us from the world of involvements.
Ward‐Based Nurses’ Knowledge and Attitudes Toward Clinical Trials: A Survey Study in Taiwan
Authors: Kao Chi‐Yin , Hamilton Bridget , Lin Yi‐Fung , Hu Wen‐Yu
Published: May 2019

Purposes

Clinical trial education has not been extensively integrated into nursing education systems. Acute care nurses may lack sufficient knowledge when caring for admitted trial patients, which may negatively influence their attitudes toward clinical trials. The aim of this study was to explore ward‐based nurses’ knowledge and attitudes toward clinical trials.

Design and Methods

Ward‐based nurses working in medical, surgical, and intensive care units in a medical center in Taiwan were approached to complete a questionnaire. The questionnaire was developed by the research team and included four parts: demographics, experience with clinical trials, clinical trial knowledge, and attitudes toward clinical trials.

Findings

A total of 161 nurses responded. Nearly 90% of the nurses accessed trial information in their workplace. Nearly 80% of the respondents had experience with caring for trial patients, but the mean score of clinical trial knowledge was 4.5 out of a possible score of 10. For attitudes toward clinical trials, the mean score for positive beliefs was 39.7, and the mean score for negative expectations was 42.5, both out of a possible score of 55. The results indicated that respondents typically tended to hold a negative attitude toward clinical trials, especially in regard to the side effects of study drugs and communication with investigators.

Conclusions

Knowledge deficits of ward‐based nurses concerning trial participation is apparent. Continuing education for ward‐based nurses is necessary to promote implementation of clinical trials and reduce negative expectations related to clinical trials.

Clinical Relevance

One way to improve nurses’ knowledge is to integrate clinical trial education into nursing education systems, which will provide more channels through which nurses can understand how a trial works, including the risks, benefits, and participant protection. Through such educational initiatives, ward‐based nurses may develop more positive beliefs regarding clinical trials and provide higher quality clinical trial care to participants.
Battle of the punches: Comparison of transection rates of different punches during FUE
Authors: Mohmand Muhammad Humayun , Ahmad Muhammad
Published: May 2019

Objectives

To know the transection rate using three different kinds of punches of the same size (0.9 mm).

Materials and methods

The study was conducted in 10 patients undergoing FUE. Informed consent was obtained from all the patients. In each patient, five areas of 1 cm2 were selected in three rows (each row having five areas of 1 cm2). For each row, one kind of punch (sharp, serrated, and blunt) was used. The rows were selected randomly (single‐blind). The machine was set at a constant speed of 1200‐1500 g. The grafts were harvested with the patient in lying position, the surgeon sitting on head side, and the harvesting started from the right side of the patient to left side. For each box, the FUs and hair were calculated. The harvested FUs were checked under microscope. Any transection (complete or incomplete) was calculated. All the data were collected and analyzed.

Results

The total hair yield was maximum with blunt punch (268.4) followed by serrated (247.2) and sharp (207.6). Similarly, the maximum FU yield was 155 using serrated punch followed by 154.4 by blunt and 147.2 in sharp punch. The hair:FUs was highest in blunt punch (1:1.738) vs serrated punch (1:1.595) vs sharp punch (1:1.410). The transection rate was highest with sharp punch (23.9%) followed by serrated (18.8%) and blunt punch (14.5%).

Conclusion

The graft:hair ratio was maximum using blunt punch. Sharp punch resulted in maximum transection rate with lowest graft:hair ratio.
Virtual Evaluation of the Accuracy of Fit and Trueness in Maxillary Poly(etheretherketone) Removable Partial Denture Frameworks Fabricated by Direct and Indirect CAD/CAM Techniques
Authors: Negm Enas Elhamy , Aboutaleb Faten Ahmed , Alam‐Eldein Ahmed M.
Published: May 2019

Purpose

To compare the accuracy of fit and trueness of maxillary poly(etheretherketone) (PEEK) removable partial denture (RPD) frameworks fabricated by direct and indirect computer‐aided design/computer‐aided manufacturing (CAD/CAM) techniques.

Materials and Methods

A definitive maxillary class I master epoxy model was duplicated to create a stone cast. The cast was scanned, and an RPD was designed. Standard tessellation language (STL) data were used to fabricate 20 identical RPD frameworks using two CAD/CAM techniques: direct milling of PEEK and indirect additive manufacturing (resin printing combined with PEEK thermopressing using the lost‐wax technique). All the frameworks for each technique (n = 10) and the reference cast were scanned. To assess the accuracy of fit, a color map was constructed using metrology software, and the misfit (distance between each framework and the reference cast) was measured at 25 standardized points. To assess the overall trueness, each framework STL file was superimposed over the original design's STL file, and the average deviation was recorded in microns. Data were statistically analyzed using t‐test.

Results

Color mapping showed distinct pressure areas in the anterior and posterior straps of the major connector in the indirect technique, while a more uniform distribution of the color map was observed in the direct technique. A significant difference was found between the two techniques regarding the overall accuracy of fit. Compared with the indirect technique, the milled frameworks showed significantly better overall trueness (p < 0.001).

Conclusions

Although a significant difference in the overall fit accuracy was noted between both techniques, the fit was an acceptable clinical fit. The fabrication method affects the fit in the anterior and posterior strap areas. The frameworks of the direct technique revealed better overall trueness values compared with the indirect technique.
Effects of methionine partially replaced by methionyl‐methionine dipeptide on intestinal function in methionine‐deficient pregnant mice
Authors: Chen Qiong , Wang Caihong , Zhao Feng‐Qi , Liu Jianxin , Liu Hongyun
Published: May 2019

This study was to compare the effects of parenteral supplementation of methionyl‐methionine (Met‐Met) or Met on intestinal barrier function in Met‐deficient pregnant mice. Pregnant mice were randomly divided into three groups. The Control group was provided a diet containing Met and received i.p. injection of saline. The Met group was fed the same diet but without Met and received daily i.p. injection of 35% of the Met contained in the control diet. The Met‐Met group was treated the same as the Met group, except that 25% of the Met injected was replaced with Met‐Met. Met‐Met promoted villus surface area in ileum compared with Met alone. In addition, the mRNA abundance of amino acid and glucose transporters in the small intestine was altered with Met‐Met. Moreover, Met‐Met increased tight junction protein and decreased apoptosis‐related proteins expression in the jejunum and ileum. These results suggest that Met‐Met can promote intestinal function over Met alone in Met‐deficient mice.
Impact of salted duck egg albumen powder on proteolysis and gelling properties of sardine surimi
Authors: Quan Tran Hong , Benjakul Soottawat
Published: May 2019

The influences of salted duck egg albumen powder (SDEAP) as salt replacer at various levels (0.5–2.5%) on autolysis and gelling properties of sardine surimi were investigated. SDEAP had high salt (33.67%) and protein contents (64.52%) with trypsin inhibitory activity of 5,975 kunits/g solid. SDEAP was white in color with L*‐value of 96.72. It had low moisture content (3.98%) and water activity (0.38). Autolysis of sardine surimi was drastically inhibited when SDEAP was incorporated with increasing levels as indicated by the more retained myosin heavy chain and the reduced trichloroacetic acid‐soluble peptide content. Breaking force and deformation of surimi gel increased, while expressible moisture content decreased as the levels of SDEAP added were increased (p < .05). Gumminess, hardness, chewiness, springiness, and cohesiveness of surimi gels also increased as SDEAP levels increased (p < .05). Lightness and whiteness were higher in all surimi gels incorporated with SDEAP than the control (p < .05). For microstructure, surimi gels incorporated with SDEAP at all levels used had finer gel network with smaller voids and more connectivity than the control gel. Thus, SDEAP could be used as a salt replacer for sardine surimi gel preparation and it could improve the properties of resulting gel.
A neural oscillations perspective on phonological development and phonological processing in developmental dyslexia
Authors: Goswami Usha
Published: May 2019

Children's ability to reflect upon and manipulate the sounds in words (“phonological awareness”) develops as part of natural language acquisition, supports reading acquisition, and develops further as reading and spelling are learned. Children with developmental dyslexia typically have impairments in phonological awareness. Many developmental factors contribute to individual differences in phonological development. One important source of individual differences may be the child's sensory/neural processing of the speech signal from an amplitude modulation (~energy or intensity variation) perspective, which may affect the quality of the sensory/neural representations (“phonological representations”) that support phonological awareness. During speech encoding, brain electrical rhythms (oscillations, rhythmic variations in neural excitability) recalibrate their temporal activity to be in time with rhythmic energy variations in the speech signal. The accuracy of this neural alignment or “entrainment” process is related to speech intelligibility. Recent neural studies demonstrate atypical oscillatory function at slower rates in children with developmental dyslexia. Potential relations with the development of phonological awareness by children with dyslexia are discussed.
Newborn physical condition and breastfeeding behaviours: Secondary outcomes of a cluster‐randomized trial of prenatal lipid‐based nutrient supplements in Bangladesh
Authors: Ullah Md Barkat , Mridha Malay K. , Arnold Charles D. , Matias Susana L. , Khan Md Showkat A. , Siddiqui Zakia , Hossain Mokbul , Paul Rina Rani , Dewey Kathryn G.
Published: May 2019

Prenatal nutritional supplements may improve birth outcomes. This study aims to examine the effect of prenatal lipid‐based nutrient supplements (LNS), compared with iron and folic acid (IFA), on general newborn physical condition and feeding behaviours. We conducted a cluster‐randomized effectiveness trial that enrolled 4,011 pregnant women at ≤20 gestational weeks. LNS and IFA were provided to women in 48 and 16 clusters, respectively, for daily consumption until delivery. We collected data on household socio‐economic, food insecurity, and maternal characteristics during early pregnancy and on newborn condition and feeding within 72 hr of delivery. We analysed intervention effects on these secondary outcomes using mixed models with analysis of covariance for continuous outcomes and logistic regression for dichotomous outcomes. Among 3,664 live births, intervention groups did not differ in newborn response, mother's rating of the general condition of her newborn, early initiation of breastfeeding (EIBF), suckling ability, or frequency and exclusivity of breastfeeding in the first 24 hr. If the mother perceived her infant to be healthy, EIBF was more likely (OR [95% CI]: 2.08 [1.46, 2.97]) and frequency of breastfeeding in the first 24 hr was greater (mean difference [95% CI]: 3.0 [1.91, 4.01]), but there was no difference in exclusive breastfeeding in the first 24 hr. Newborn condition and early breastfeeding practices were not affected by giving mothers prenatal LNS versus IFA. However, early breastfeeding practices were related to maternal perception of her newborn's condition. Thus, interventions to improve breastfeeding practices for newborns with poorer perceived health status may be useful.
A comparison of exclusive breastfeeding in Belgian maternity facilities with and without Baby‐friendly Hospital status
Authors: Robert Emmanuelle , Michaud‐Létourneau Isabelle , Dramaix‐Wilmet Michèle , Swennen Béatrice , Devlieger Roland
Published: May 2019

A retrospective cross‐sectional study was carried out in Wallonia (the southern region of Belgium) in which a 20‐question breastfeeding (BF) module was included in an immunization survey. The purpose of this paper is to compare exclusive breastfeeding (EBF) prevalences and BF practices for mothers giving birth in Baby‐friendly Hospital Initiative (BFHI) and non‐BFHI maternity facilities. A total of 557 mothers responded to BF questions when their child was 18–24 months old; 26.7% of them delivered in a BFHI maternity facility. At discharge, a larger proportion of children were exclusively breastfed if they were born in a BFHI maternity facility (76.5% vs. 65.8%, p = .02). The median duration of EBF (15.0 vs. 12.9 weeks, p = .3), and the proportion of children exclusively breastfed at 5 months (16.8% vs 15.8%, p = 1.0) were similar in both groups. Few mothers knew that EBF was recommended for the first 6 months of life (28.6% in BFHI vs 23.1% in non‐BFHI, p = .2). For most groups of the population examined, the rates of BF tended to be higher in BFHI facilities, but many differences were not significant. More specifically, BFHI seemed to boost BF practices among mothers more likely to breastfeed, but the Initiative did not seem to trigger enhanced BF practices in mothers traditionally less likely to breastfeed (except for indifferent/negative partner's attitude and mothers of Belgian origin). Influencing the BF practices of mothers less likely to breastfeed requires a special attention with complementary actions in maternity facilities as well as in community services.
Aligning direct observation and assessment
Authors: Gauthier Stephen
Published: May 2019

When is observation direct observation? Gauthier argues one must understand the competencies addressed by specific assessment tools to capitalize on direct observation in clinical practice.
Experience‐based learning: junior medical students’ reflections on end‐of‐life care
Authors: Wilson Hamish , Warmington Sally , Johansen May‐Lill
Published: May 2019

Context

Experience‐based learning may contribute to confidence, competence and professional identity; early experiences may be particularly formative. This study explored how pre‐clinical students make sense of their participation in the provision of end‐of‐life care within community settings.

Methods

We performed dialogic narrative analysis on essays written by junior medical students in New Zealand. Students had reflected on their participation as assistant caregivers in nursing homes, contributing to the personal care of the elderly residents who lived there. Essays had been submitted to a reflective writing competition that was run separately from the students’ medical studies. We analysed five essays about nursing placements, focusing on students’ stories about their engagement with residents who were suffering or were receiving end‐of‐life care.

Results

In their essays, students wrote about powerful and at times intense learning experiences during these early clinical attachments; their attitudes to death and dying were both highlighted and changed. Allied health professionals (e.g. caregivers) provided important support for student learning, especially in relation to seminal encounters such as those occurring in the course of providing end‐of‐life care. Support increased students’ participation and confidence. Reflective writing helped students make sense of their learning and led them to think about their own professional identities, even in the absence of observing or working with doctors in those settings.

Conclusions

Students’ reflections revealed that they tend to filter their learning experiences through the lens of future doctoring, especially when involved in challenging clinical situations. Although medical schools have limited influence on interprofessional relationships or mentoring within the environment of community hospitals, support from other staff can help junior students make the most of their engagement in end‐of‐life care. In‐depth reflection may facilitate the links between experience‐based learning and students’ emerging ideas about their own professional identities, but the underlying mechanisms need further exploration.
Outcomes of percutaneous vacuum‐assisted debulking of large vegetations as an adjunct to lead extraction
Authors: Kiani Soroosh , Sabayon Dean , Lloyd Michael S. , Hoskins Michael H. , El‐Chami Mikhael F. , Westerman Stacy , Vadlamudi Ratna , Keeling Brent , Lattouf Omar M. , Merchant Faisal M.
Published: May 2019

Background

Consensus statements on lead extraction give consideration to open surgical removal in the setting of large vegetations, to mitigate the risk of massive embolism that may occur with percutaneous lead removal. Vacuum‐assisted debulking (VD) of large vegetations as an adjunct to percutaneous lead extraction may provide an opportunity to mitigate these risks.

Methods

We retrospectively identified all patients undergoing lead extraction at our institution for endovascular infection from 2012 to 2018 and stratified them into two groups based on presence of adjunctive VD (n = 6) or without VD (no‐VD, n = 39). VD was performed with the AngioVac system (Angio‐Dynamics, Latham, NY, USA).

Results

Across the cohort, mean age was 62 ± 15 years, ejection fraction was 41 ± 16%, and 39% had end‐stage renal disease on dialysis. Defibrillator systems were present in 71%, and 22% had cardiac resynchronization devices. Mean duration of the oldest extracted lead was 6.3 ± 4.9 years. There were no significant differences in baseline covariates between groups. Those in the VD group were significantly less likely to have Staphylococcus aureus as a causative organism (P = .04). In the VD group, vegetations targeted for debulking ranged in size from 1.8 to 6 cm (longest dimension). There were no operative deaths or clinically evident embolic events in either group. The overall nonfatal complication rate in the VD group was higher (33.3% vs 2.3%, P = .043).

Conclusion

: VD can be performed as an adjunct to percutaneous lead extraction with a reasonable safety profile. The relative safety and efficacy of this approach removal requires further study.
Mega‐environment identification for soybean (Glycine max) breeding and production in Brazilian Midwest region
Authors: Zdziarski Andrei D. , Woyann Leomar G. , Milioli Anderson S. , Zanella Rodrigo , Dallacorte Lucas V. , Panho Maiara C. , Benin Giovani
Published: May 2019

Mega‐environment (ME) identification is the first step for evaluating, selecting and recommending genotypes within a target region (TR). The present study aimed to (a) identify MEs, using GGE biplot methods, in Brazilian edaphoclimatic region (ECR) 402 of soybean cultivation, located in the Mato Grosso State (the TR) and (b) compare the performance of genotypes within the TR and in each ME using fixed and mixed models. Data from three years of soybean yield trials, 19 genotypes and 22 environments were used. The biplots GGE, GGL + GGE and GGS + GGE were implemented to identify the MEs. Two MEs were identified in the TR. ME1 presents a higher altitude, farms which use a higher level of fertilizer inputs and a higher occurrence of the soybean cyst nematode (SCN) than ME2. When selection and recommendation are made based on MEs, genotypes with both broadly and specific adaptation can be selected. This action can improve grain yield in the entire target region.
The Impact of Foreign Agricultural Aid and Total Foreign Aid on Agricultural Output in African Countries: New Evidence from Panel Data Analysis
Authors: Barkat Karim , Alsamara Mouyad
Published: May 2019

Official Development Assistance may play an important role in increasing the resources to finance the agriculture sector and improve agricultural outcomes in African countries. Although this is a relevant issue, very few studies have investigated the link between foreign agricultural aid and national agricultural output. Using advanced econometrics techniques, this paper examines the impact of foreign agricultural aid and foreign aid on agriculture output in the panel data set of 29 African countries over the period of 1975–2013. In particular, we employed two estimation methods: Augmented Mean Group and Common Correlated Effects‐2SLS. The first method accounts for heterogeneous slope coefficients across group members and cross‐sectional dependency among variables, whereas the second method accounts for endogenous regressors. Our main findings indicate a small and positive impact of foreign agricultural aid and total foreign aid on agricultural output for low‐ and middle‐income countries. Furthermore, the Pairwise Dumitrescu‐Hurlin Panel Causality test shows evidence of a bidirectional causal relationship between agricultural aid and agricultural output for the full sample, noting that the result changes at the different group income level. Based on the empirical results, recommendations for future policy are given.
Inertia Risk: Improving Economic Models of Catastrophes*
Authors: Crépin Anne‐Sophie , Nævdal Eric
Published: May 2019

We model endogenous catastrophic risk in a new way. We call it “inertia risk”, which accounts for delays between physical variables and the hazard rate – a characteristic often observed in reality. The added realism significantly affects optimal policies relative to the standard model of catastrophic risk. The probability of a catastrophe occurring at some point in time can span the entire interval [0,1], and is not 0 or 1 as is typical in standard models. Inertia risk can also generate path dependences. We illustrate the implications for policy in a simple model of climate change.
Detecting Historical Inequality Patterns: A Replication of Thomas Piketty's Wealth Concentration Estimates for the United Kingdom
Authors: Magness Phillip W.
Published: May 2019

Objective

This article utilizes a replication exercise to evaluate the reliability of the historical time series for top wealth share concentrations in the United Kingdom, as presented in Thomas Piketty's Capital in the Twenty‐First Century (2014a).

Method

Using Piketty's identified source records, an attempt is made to replicate the construction of his time series for top wealth concentrations in the U.K. These results are then compared against the series presented in Capital, and subsequent improvements by other scholars.

Results

Piketty's time series is shown to diverge substantially from its source data from the U.K., and does not appear to be replicable. In particular, Piketty's series introduces a sizable post‐1980 adjustment that suggests a substantially more rapid acceleration of wealth concentration than its source statistics reveal. Issues of reliability in the U.K. time series mirror similar problems with Piketty's wealth estimates for the United States, although their implications for historical interpretation differ in light of subsequent data.

Conclusion

These findings indicate that Piketty's account of changing wealth concentrations in the United Kingdom in the 20th century is unreliable for interpreting recent patterns in the evolution of top wealth shares. An alternative interpretation of the source data is therefore offered, pointing to a century‐long L‐shaped pattern in place of Piketty's depicted U‐curve.
Impact of heat and drought stress on peroxisome proliferation in quinoa
Authors: Hinojosa Leonardo , Sanad Marwa N.M.E. , Jarvis David E. , Steel Patrick , Murphy Kevin , Smertenko Andrei
Published: May 2019

Although peroxisomes play a key role in plant metabolism under both normal and stressful growth conditions, the impact of drought and heat stress on the peroxisomes remains unknown. Quinoa represents an informative system for dissecting the impact of abiotic stress on peroxisome proliferation because it is adapted to marginal environments. Here we determined the correlation of peroxisome abundance with physiological responses and yield under heat, drought and heat plus drought stresses in eight genotypes of quinoa. We found that all stresses caused a reduction in stomatal conductance and yield. Furthermore, H2O2content increased under drought and heat plus drought. Principal component analysis demonstrated that peroxisome abundance correlated positively with H2O2content in leaves and correlated negatively with yield. Pearson correlation coefficient for yield and peroxisome abundance (r = −0.59) was higher than for commonly used photosynthetic efficiency (r = 0.23), but comparable to those for classical stress indicators such as soil moisture content (r = 0.51) or stomatal conductance (r = 0.62). Our work established peroxisome abundance as a cellular sensor for measuring responses to heat and drought stress in the genetically diverse populations. As heat waves threaten agricultural productivity in arid climates, our findings will facilitate identification of genetic markers for improving yield of crops under extreme weather patterns.
The association of inpatient blood utilization and diagnosis‐related group weight: implications for risk‐adjusted benchmarking
Authors: Metcalf Ryan A. , White Sandra K. , Potter Scott , Barney Reed , Hunter Cheri , White Michael , Enniss Toby , Galaviz Charles , Reddy Santosh , Wanner Nathan , Schmidt Robert L. , Blaylock Robert
Published: May 2019

BACKGROUND

Risk‐adjusted benchmarking could be useful to compare blood utilization between hospitals or individual groups, such as physicians, while accounting for differences in patient complexity. The aim of this study was to analyze the association of red blood cell (RBC) use and diagnosis‐related group (DRG) weights across all inpatient hospital stays to determine the suitability of using DRGs for between‐hospital risk‐adjusted benchmarking. Specific hierarchical organizational units (surgical vs. nonsurgical patients, departments, and physicians) were also evaluated.

STUDY DESIGN AND METHODS

We studied blood use among all adult inpatients, and within organizational units, over 4 years (May 2014 to March 2018) at an academic center. Number of RBCs transfused, all patient refined (APR)‐DRGs, and other variables were captured over entire hospital stays. We used multilevel generalized linear modeling (zero‐inflated negative binomial) to study the relationship between RBC utilization and APR‐DRG.

RESULTS

A total of 97,955 hospital stays were evaluated and the median APR‐DRG weight was 1.2. The association of RBCs transfused and APR‐DRG weight was statistically significant at all hierarchical levels (incidence rate ratio = 1.22; p < 0.001). The impact of APR‐DRG on blood use, measured by the incidence rate ratio, demonstrated an association at the all‐patient and surgical levels, at several department and physician levels, but not at the medical patient level. The relationship between RBCs transfused and APR‐DRG varied across organizational units.

CONCLUSION

Number of RBCs transfused was associated with APR‐DRG weight at multiple hierarchical levels and could be used for risk‐adjusted benchmarking in those contexts. The relationship between RBC use and APR‐DRG varied across organizational units.
Local-global principles in circle packings
Authors: Fuchs Elena , Stange Katherine E. , Zhang Xin
Published: May 2019

We generalize work by Bourgain and Kontorovich [On the local-global conjecture for integral Apollonian gaskets, Invent. Math.196(2014), 589–650] and Zhang [On the local-global principle for integral Apollonian 3-circle packings, J. Reine Angew. Math.737, (2018), 71–110], proving an almost local-to-global property for the curvatures of certain circle packings, to a large class of Kleinian groups. Specifically, we associate in a natural way an infinite family of integral packings of circles to any Kleinian group${\mathcal{A}}\leqslant \text{PSL}_{2}(K)$satisfying certain conditions, where$K$is an imaginary quadratic field, and show that the curvatures of the circles in any such packing satisfy an almost local-to-global principle. A key ingredient in the proof is that${\mathcal{A}}$possesses a spectral gap property, which we prove for any infinite-covolume, geometrically finite, Zariski dense Kleinian group in$\operatorname{PSL}_{2}({\mathcal{O}}_{K})$containing a Zariski dense subgroup of$\operatorname{PSL}_{2}(\mathbb{Z})$.
Robinson’s conjecture on heights of characters
Authors: Feng Zhicheng , Li Conghui , Liu Yanjun , Malle Gunter , Zhang Jiping
Published: May 2019

Geoffrey Robinson conjectured in 1996 that the $p$-part of character degrees in a $p$-block of a finite group can be bounded in terms of the center of a defect group of the block. We prove this conjecture for all primes $p\neq 2$ for all finite groups. Our argument relies on a reduction by Murai to the case of quasi-simple groups which are then studied using deep results on blocks of finite reductive groups.
Linear syzygies, hyperbolic Coxeter groups and regularity
Authors: Constantinescu Alexandru , Kahle Thomas , Varbaro Matteo
Published: May 2019

We show that the virtual cohomological dimension of a Coxeter group is essentially the regularity of the Stanley–Reisner ring of its nerve. Using this connection between geometric group theory and commutative algebra, as well as techniques from the theory of hyperbolic Coxeter groups, we study the behavior of the Castelnuovo–Mumford regularity of square-free quadratic monomial ideals. We construct examples of such ideals which exhibit arbitrarily high regularity after linear syzygies for arbitrarily many steps. We give a doubly logarithmic bound on the regularity as a function of the number of variables if these ideals are Cohen–Macaulay.
A Coupled Thermomechanical Modeling Method for Predicting Grinding Residual Stress Based on Randomly Distributed Abrasive Grains
Authors: Nie Zhenguo , Wang Gang , Wang Liping , Rong Yiming (Kevin)
Published: May 2019

In this research, we propose a coupled thermomechanical modeling method for predicting grinding residual stress based on randomly distributed grains. In order to deal with the problem that the nominal grinding force is too small to generate the plastic deformation, we hold the opinion that grinding residual stress is totally derived from three factors: thermal stress, the nominal grinding force (pressure) over the entire grinding zone, and the equivalent plowing force just under the bottom of the abrasive wheel. Finite element model (FEM) simulation of the single-grain grinding (SGG) is conducted to obtain the critical plowing depth and the SGG force at an arbitrary cutting depth. Based on the randomly distributed abrasive grains, the equivalent grinding heat source model, the equivalent SGG plowing force model, and the equivalent nominal pressure model are all established. A 2D coupled thermomechanical model is established to simulate the grinding process for temperature fields and grinding residual stress fields. In addition, verification tests are conducted to validate the model. It turns out that the coupled model can accurately predict the multiphysical fields on both temperature and residual stress. Based on the simulation results of the model, the generation mechanism of grinding residual stress is quantitatively studied. This research provides a promising pathway to residual stress control of grinding.
Computational Fluid Dynamics Modeling and Experimental Validation of the Thermofluidic Performance of Climatic Chambers
Authors: Silva R. , Brett M. , Ferreira Almerindo D. , Serra C. , Jesus T. , Fino M. , Tadeu A. , Mendes J. , Raújo J. , Santos R.
Published: May 2019

Climatic chambers are of great importance in research and development to conduct tests of components in closed environmentally controlled conditions. The growing demand from the industry to fulfill stricter international standards creates the necessity to ensure that the thermofluidic behavior of climatic chambers guarantees high-quality consistency in their interior domain. At present, scientific research on climatic chambers available in the literature is scarce and is mostly based on lumped modeling, hence not addressing the heterogeneities that arise in the interior of the chamber. In this work, an in-depth 3D model of the velocity and temperature fields that develops in the interior of climatic chambers was developed in computer fluid dynamics (CFD) and validated with the experimental data from a new prototype. The key objective of this research was to establish a validated framework for model-based design optimization of climatic chambers. The proposed model showed good agreement with the experimental data with a difference of 0.6 m/s and 9.65 °C in the velocity and temperature fields, respectively, thus validating its applicability to perform model-based design optimization of climatic chambers.
An Experimental Study on Combustion and Performance of a Liquefied
Natural Gas–Diesel Dual-Fuel Engine With Different Pilot Diesel
Quantities
Authors: Song Jiantong , Wang Guna
Published: May 2019

The pilot diesel quantity (mpilot) has an impact on the liqueified nitrogen gas (LNG)-diesel dual-fuel engine, but it is very difficult for a dual-fuel engine with the traditional injection system to adjust mpilot to meet various operating conditions in practice. In recent years, with great progress in common rail diesel injection technology, mpilot can be adjusted accurately by the electronic control system, which is an advantage for operation with the diesel–LNG dual-fuel. In order to optimize mpilot of the diesel–LNG dual-fuel engine, the combustion and performance of a dual-fuel engine with the mpilot of 5.05 mg/cyc, 5.20 mg/cyc, 5.69 mg/cyc, 6.31 mg/cyc and 6.91 mg/cyc under 50% load at speed of 1600 r/min were analyzed. Experimental results show that, with an increase in mpilot, the maximum in-cylinder pressure, rate of pressure rise, and heat release rate of dual-fuel obviously increase, the crank angles of the maximum value move forward, and the combustion duration becomes shorter. The mean value of peak in-cylinder pressure (pmax) increases obviously while the standard deviation of it decreases, and the distribution of that focuses. The mean value of the crank angle corresponding to pmax pressure decreases except for the mpilot of 5.05 mg/cyc, while the standard deviation of that gradually decreases, the distribution of it focuses and moves forward. The brake power increases while the brake-specific fuel consumption (BSFC) decreases, the CO and HC decrease, while the CO2, NOx, and smoke density emissions increase.
Bidirectional Spiral Pulley Negative Stiffness Mechanism for Passive Energy Balancing
Authors: Zhang Jiaying , Shaw Alexander D. , Amoozgar Mohammadreza , Friswell Michael I. , Woods Benjamin K. S.
Published: May 2019

The energy balancing concept seeks to reduce actuation requirements for a morphing structure by strategically locating negative stiffness devices to tailor the required deployment forces and moments. One such device is the spiral pulley negative stiffness mechanism. This uses a cable connected with a pre-tension spring to convert the decreasing spring force into the increasing balanced torque. The kinematics of the spiral pulley is first developed for bidirectional actuation, and its geometry is then optimized by employing an energy conversion efficiency function. The performance of the optimized bidirectional spiral pulley is then evaluated through the net torque, the total required energy, and energy conversion efficiency. Then, an additional test rig tests the bidirectional negative stiffness property and compares the characteristics with the corresponding analytical result. Exploiting the negative stiffness mechanism is of significant interest not only in the field of morphing aircraft but also in many other energy and power reduction applications.
Effect of cochlear implant n-of-m strategy on signal-to-noise ratio below which noise hinders speech recognition
Authors: Stam Lucas , Goverts S. Theo , Smits Cas
Published: May 2019

Speech recognition was measured in 24 normal-hearing subjects for unprocessed speech and for speech processed by a cochlear implant Advanced Combination Encoder (ACE) coding strategy in quiet and at various signal-to noise ratios (SNRs). All signals were low- or high-pass filtered to avoid ceiling effects. Surprisingly, speech recognition performance plateaus at approximately 22 dB SNR for both speech types, implying that ACE processing has no effect on the upper limit of the effective SNR range. Speech recognition improved significantly above 15 dB SNR, suggesting that the upper limit used in the Speech Intelligibility Index should be reconsidered.
Cross-correlation of shipping noise: Refraction and receiver-motion effects
Authors: Skarsoulis E. K. , Cornuelle B. D.
Published: May 2019

The spatial correlation of a diffuse isotropic noise field generated from a uniform distribution of uncorrelated noise sources contains information about the time-domain Green's function (TDGF) corresponding to propagation between the correlated locations. The distribution of noise in the ocean due to shipping—the prevailing origin of continuous low-frequency noise—is far from uniform. Besides the location of noise sources, the propagation conditions and the hydrophone locations have a significant influence on whether the TDGF can be reliably reconstructed through the cross-correlation procedure. A wave-theoretic scheme is implemented to simulate the cross-correlation function of a noise field in the time domain for arbitrary distributions of deterministic or random noise sources in refractive environments, and it is used to study the influence of propagation conditions and receiver motion on the efficiency of the cross-correlation procedure to obtain the TDGF from shipping noise.
Effects of stimulus cosine onset properties on bottlenose dolphin (Tursiops truncatus) auditory brainstem responses
Authors: Jones Ryan , Finneran James J. , Mulsow Jason , Burkard Robert F.
Published: May 2019

Although the auditory brainstem response (ABR) is known to be an onset response, the specific relationship between stimulus onset properties and the resulting ABR is not well understood. In this study, the effects of stimulus onset on dolphin ABR were examined by measuring ABRs in six bottlenose dolphins while systematically manipulating rise time and plateau sound pressure of cosine-enveloped noise bursts. Noise bursts were spectrally “pink” with frequency content from 10 to 160 kHz, rise times from 32 μs to 4 ms, and plateau sound pressure levels from 102 to 138 dB re 1 μPa. Envelope rise time and plateau sound pressure alone were found to be poor predictors for ABR peak amplitudes and latencies. Peak amplitudes were well described by the envelope sound pressure at the end of a 260-μs window; however, best-fits to the data across ABR peaks were obtained when the window start time was allowed to vary. Peak latencies were best described by the maximum value of the second derivative of the pressure envelope. These results are consistent with single-unit and nearfield response data for terrestrial mammals and indicate that stimuli with rise times greater than 260 μs are non-optimal with respect to maximizing ABR amplitudes.
Assessing a Two-Pronged Approach to Active Learning in Sport Sociology Classrooms
Authors: Dane-Staples Emily
Published: May 2019

Active-learning research has explored 2 distinct areas: pedagogy and physical space. As existing research has most often explored only 1 area per study and few have been done in the area of sport sociology, additional research is needed. This research combined both areas of active learning through a quasi-experimental design. Using 2 different classes, Sport and Society and Gender and Sport, students were exposed to an unchanging physical space or manipulated physical space, as well as active-learning tasks of varying complexity. No differences in student perceptions of engagement or learning were found when comparing space variations; however, task complexity did lead to significant differences in student perceptions of engagement and learning.