scholarly journals 551 The Relationship Between Canal Diameter and the DORR Classification - Presented by Dr John Vincent and Dr Ryan Doherty of NIMDTA, formerly Queen's University Belfast

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
P N Karayiannis ◽  
R S Cassidy ◽  
J C Hill ◽  
L D Dorr ◽  
D E Beverland

Abstract Background Particularly in broach-only uncemented total hip arthroplasty, a narrow femoral canal presents a technical challenge. Traditionally such femurs have been considered to be Dorr A. To our knowledge, however, no study has reported on the relationship between isthmus width and the Dorr classification. Method We reviewed 500 high-quality, hard copy radiographs. Dorr classification and isthmus canal width were measured using an electronic caliper by 5 independent observers with intraobserver and interobserver error calculated. For this study, we defined a narrow canal as being 10 mm at its narrowest point (isthmus). Results Eight percent (40) were Dorr A, 85% (424) Dorr B, and 7% (36) Dorr C. With respect to isthmus width for Dorr A, 63% (25) were 10 mm compared to just 13% (55) of Dorr B. However, overall because there were more Dorr B femurs, 69% of those with an isthmus of 10 mm were Dorr B. Conclusions In this population, almost 70% of patients with an isthmus 10 mm were Dorr B, with only 30% being Dorr A. When using a broach-only technique, isthmus width should be routinely measured on the preoperative anteroposterior radiographs so as to alert the surgeon to potential problems.

2019 ◽  
Vol 63 (3) ◽  
pp. 115-128 ◽  
Author(s):  
Maie Stein ◽  
Sylvie Vincent-Höper ◽  
Nicole Deci ◽  
Sabine Gregersen ◽  
Albert Nienhaus

Abstract. To advance knowledge of the mechanisms underlying the relationship between leadership and employees’ well-being, this study examines leaders’ effects on their employees’ compensatory coping efforts. Using an extension of the job demands–resources model, we propose that high-quality leader–member exchange (LMX) allows employees to cope with high job demands without increasing their effort expenditure through the extension of working hours. Data analyses ( N = 356) revealed that LMX buffers the effect of quantitative demands on the extension of working hours such that the indirect effect of quantitative demands on emotional exhaustion is only significant at low and average levels of LMX. This study indicates that integrating leadership with employees’ coping efforts into a unifying model contributes to understanding how leadership is related to employees’ well-being. The notion that leaders can affect their employees’ use of compensatory coping efforts that detract from well-being offers promising approaches to the promotion of workplace health.


2021 ◽  
Author(s):  
Robbie I’Anson Price ◽  
Francisca Segers ◽  
Amelia Berger ◽  
Fabio S Nascimento ◽  
Christoph Grüter

Abstract Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only advertise high quality food sources, thereby filtering out less adaptive information. Stingless bees, a large pantropical group of highly eusocial bees, face intense inter- and intra-specific competition for limited resources, yet display disparate foraging strategies. Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not. Our current understanding of why some species communicate foraging sites while others do not is limited. Studying freely foraging colonies of several co-existing stingless bee species in Brazil, we investigated if recruitment to specific food locations is linked to (1) the sugar content of forage, (2) the duration of foraging trips and (3) the variation in activity of a colony from one day to another and the variation in activity in a species over a day. We found that, contrary to our expectations, species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates. Furthermore, foragers from recruiting species did not have shorter foraging trip durations than those from weakly-recruiting species. Given the intense inter- and intraspecific competition for resources in these environments, it may be that recruiting species favour food resources that can be monopolised by the colony rather than food sources that offer high-quality rewards.


2011 ◽  
Vol 243-249 ◽  
pp. 4956-4959
Author(s):  
Jian Chao Hao ◽  
Hui Fen Liu ◽  
Dong Ling Wei ◽  
Li Jun Shi ◽  
Jun Li Li ◽  
...  

The relationship between formaldehyde emission and time was researched and a mathematical model was developed which describes the variation of formaldehyde with time in the airtight chamber. It was found that high quality composite floor was in line with 0-order kinetic equation and low quality composite floor was in line with 1-order kinetic equation. Besides, the effect of activated carbon adsorption on formaldehyde was studied and the result showed that activated carbon had poor adsorption on formaldehyde for weak van der waals force.


2015 ◽  
Vol 3 (2) ◽  
pp. 121
Author(s):  
Ying-Leh Ling ◽  
Fairuz Ismail ◽  
Abdul Ghani Kanesan Abdullah

This study aims to examine the relationship between feedback environment practices and creativity in the educational organizations. This study is a quantitative study. A total of 40 polytechnic students from Polytechnic Kuching Sarawak are randomly selected to participate in this study. Data were obtained using a set of questionnaire consisting of three parts. The data obtained were analyzed descriptively and inferentially. Inferential analysis involves <em>t</em> test and Pearson correlation. The findings have shown that the level of feedback environment based on students' perception is high. Simultaneously, the level of creativity among the students is also high. The findings indicated that there is no significant difference in feedback environment between genders. Furthermore, the study also showed a significant and positive relationship between feedback environment and students’ creativity. The results of this study have several implications directly to the formation of high-quality students as feedback environment and students’ creativity are interrelated and inseparable in educational organizations.


2017 ◽  
Vol 28 (4) ◽  
pp. 1136-1159
Author(s):  
Dusan Markovic ◽  
Mrdjan Mladjan

Following the recent wave of globalization, the possession of different types of knowledge became even more important for economic development than the possession of physical resources. The ability of a society to adopt existing and create new knowledge thus gained fundamental importance for its wellbeing. In this paper, we identify important aspects of the relationship between education, creation of knowledge, economic growth, as well as both material and immate?rial wellbeing of a society. We describe potential problems that prevent societies from maximizing the benefit from the effort its members invest in acquiring knowledge. The problems of failure of the national markets for education as well as the global migrations which lead to drain of knowledge towards economically highly developed countries are especially analyzed. In the long run, they lead to a decline in both national competitiveness and different aspects of the immate?rial wellbeing. As the basis for solving these problems we propose a combination of economic theory and the concept of solidarity between more and less devel?oped countries, individuals and societies of their origin, respecting the free will of individuals.


2019 ◽  
Author(s):  
Hua Xu ◽  
Xin Wang ◽  
Zhikai Wang ◽  
Jianhui Li ◽  
Zhiming Xu ◽  
...  

Abstract Background: MicroRNAs (miRNAs) are a class of noncoding small RNAs that play important roles in many physiological processes by regulating gene expression. Previous studies have shown that the expression levels of total miRNAs increase during mouse embryonic development, and some miRNAs control the regulatory network in development progression. However, few studies have focused on the effects of miRNAs on early human embryonic development. The relationship between miRNAs and early human embryogenesis is still unknown. Results:In this study, RNA-seq data collected from sperm samples from 102 patients with a normal sperm index but treated with assisted reproductive technology (ART) were analyzed for the relationships between differentially expressed small RNAs and the fertilization rate (FR), blastocyst rate and high-quality embryo rate (HQER). The sperm samples with high hsa-mir-191 expression had a higher FR, effective embryo rate (EER) and HQER. hsa-mir-191 was used as a single indicator to predict the HQER. The receiver operating characteristic (ROC) curve had an area under the ROC curve (AUC) of 0.686. We also found that hsa-mir-191 expression is correlated with an abnormal sperm rate (cor = 0.29, p< 0.01). We also evaluated the relationship between hsa-mir-34c and early human embryo development in these 102 sperm samples and obtained negative results. Conclusions: These findings suggest that high hsa-mir-191-5p expression in sperm is associated with early human embryonic quality and that hsa-mir-191-5p could be used as a potential marker to screen high-quality sperm to improve the success rates of in vitro fertilization (IVF).


2019 ◽  
Author(s):  
Hua Xu ◽  
Xin Wang ◽  
Zhikai Wang ◽  
Jianhui Li ◽  
Zhiming Xu ◽  
...  

Abstract Background : MicroRNAs (miRNAs) are a class of noncoding small RNAs that play important roles in many physiological processes by regulating gene expression. Previous studies have shown that the expression levels of total miRNAs increase during mouse embryonic development, and some miRNAs control the regulatory network in development progression. However, few studies have focused on the effects of miRNAs on early human embryonic development. The relationship between miRNAs and early human embryogenesis is still unknown. Results: In this study, sperm samples from 102 patients with a normal sperm index but treated with assisted reproductive technology (ART) were collected for small RNA sequencing, and the relationships between differentially expressed small RNAs and the fertilization rate (FR), blastocyst rate and high-quality embryo rate (HQER) were analyzed. The sperm samples with high hsa-mir-191 expression had a higher FR, effective embryo rate (EER) and HQER. hsa-mir-191 was used as a single indicator to predict the HQER. The receiver operating characteristic (ROC) curve had an area under the ROC curve (AUC) of 0.686. We also found that hsa-mir-191 expression is correlated with an abnormal sperm rate (cor = 0.29, p < 0.01). We also evaluated the relationship between hsa-mir-34c and early human embryo development in these 102 sperm samples and obtained negative results. Conclusions: These findings suggest that high hsa-mir-191-5p expression is associated with improved early human embryonic development and that hsa-mir-191-5p could be used as a potential marker to screen high-quality sperm to improve the success rates of in vitro fertilization (IVF).


Author(s):  
Mark P. Sena ◽  
C. Edward Heath ◽  
Michael A. Webb

Buyers on eBay commonly rely on seller feedback ratings to determine bidding strategies.  Various studies have examined the impact of eBay’s reputation system on auction outcomes.  This study builds on prior research by examining the relationship between seller ratings on auction prices for two distinct product types, DVDs and designer watches and by benchmarking the bid prices against retail prices. The results show that eBay ratings explain a greater degree of price variation in Designer Watches than in DVDs.  The study also suggests that high quality product listings with such features as digital images, formatted pages, and product details may result in higher bid prices.


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