Classification of Carpiodes Using Fourier Descriptors: A Content Based Image Retrieval Approach

Taxonomic classification has always been important to the study of any biological system. Many biological species will go unclassified and become lost forever at the current rate of classification. The current state of computer technology makes image storage and retrieval possible on a global level. As a result, computer-aided taxonomy is now possible. Content based image retrieval techniques utilize visual features of the image for classification. By utilizing image content and computer technology, the gap between taxonomic classification and species destruction is shrinking. This content based study utilizes the Fourier Descriptors of fifteen known landmark features on three Carpiodes species: C.carpio, C.velifer, and C.cyprinus. Classification analysis involves both unsupervised and supervised machine learning algorithms. Fourier Descriptors of the fifteen known landmarks provide for strong classification power on image data. Feature reduction analysis indicates feature reduction is possible. This proves useful for increasing generalization power of classification

Paradoxical low-flow, low-gradient aortic stenosis despite preserved left ventricular ejection fraction : new insights from weights of operatively excised aortic valves

Aims : We reported that patients with small aortic valve area (AVA) and low flow despite preserved left ventricular ejection fraction (LVEF), i.e. ‘paradoxical’ low flow (PLF), have worse outcomes compared with patients with normal flow (NF), although they generally have a lower mean gradient (MG). The aortic valve weight (AVW) excised at the time of valve replacement is a flow-independent marker of stenosis severity. The objective of this study was to compare the AVW of patients with PLF and MG,40 mmHg with the AVW of patients with NF and MG=40 mmHg. Methods and results : We recruited 250 consecutive patients undergoing valve replacement (Cohort A) for severe stenosis. Among them, 33 (13%) were in PLF [LVEF > 50% but stroke volume index (SVi) = 35 mL/m2] with MG 50% and SVi > 35 mL/m2) with MG = 40 mmHg (NF-HG group). Despite a much lower MG (29 ± 7 vs. 53 ± 10 mmHg; P < 0.0001), patients in the PLF-LG group had a similar AVA (0.73 ± 0.12 vs. 0.69 ± 0.13; P = 0.19) compared with those in the NF-HG group. The AVW [median (interquartile): 1.90 (1.63–2.50) vs. 2.60 (1.66–3.32)] and prevalence of bicuspid phenotype (15 vs. 42%) were lower in the PLF-LG group than in the NF-HG group. However, AVWs analysed separately in the tricuspid and bicuspid valves were similar in both groups [tricuspid valves: 1.80 (1.63–2.50) vs. 2.30 (1.58–3.00) g; P = 0.26 and bicuspid valves: 2.72 (1.73–3.61) vs. 2.60 (2.10–3.55) g; P = 0.93]. When using cut-point values of AVW established in another series of non-consecutive patients (n = 150, Cohort B) with NF and concordant Doppler-echocardiographic findings, we found that the percentage of patients with evidence of severe stenosis in Cohort A was 70% in patients with PLF-LG and 86% in patients with NF-HG. Conclusion : The aortic valve weight data reported in this study provide evidence that a large proportion of patients with PLF and low-gradient have a severe stenosis and that the gradient may substantially underestimate stenosis severity in these patients. A multi-parametric approach including all Doppler-echocardiographic parameters of valve function as well as other complementary diagnostic tests may help correctly identify these patients

Epidemiology and survival of the five stages of chronic kidney disease in a systolic heart failure population

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102653/1/ejhfhfq077.pd

The chief diversity officer in a global environment: A systematic review

The business problem addressed in this dissertation is that chief diversity officers (CDOs) are responsible for changing the organizational culture and strategically increasing diversity, equity, and inclusion (DE&I) as a sole individual, when successful change begins with organizational leadership and individual employees as key contributors for change in a global environment.To this end, how CDOs can foster an organizational culture that adheres to inclusive excellence is an emerging strategic priority globally. There is a growing body of literature that addresses the role of the CDO; however, there is a need to understand how this role can strategically introduce an organizational DE&Iimplementation plan in a global environment. This qualitative systematic review explored peer-reviewed research from severalresearch databases and grey literature identified through a snowballing method in order to develop an understanding of how CDOs can use diversity-themed strategic priorities to create an organizational implementation plan. The research process led to 491 articles published from 2015–2020 being identified. Sixty three articles were included in this study upon a quality appraisal technique being applied. Systems theory, theory of organizational commitment, and transformational leadership theory were combined as adecisional framework to evaluate the research question and guide the research process. Seven themes emerged in this study, using thematic analysis and deductive coding as an analytical strategy that can provide CDOs with guidance on developing and implementing a strategic organizational DE&I plan. Implications for future research are assessed.THE CHIEF DIVERSITY OFFICER i ABSTRACT Title of Dissertation: THE CHIEF DIVERSITY OFFICER IN A GLOBAL ENVIRONMENT: A SYSTEMATIC REVIEW Don Patrick Trahan, Jr., Doctor of Business Administration, 2021 The business problem addressed in this dissertation is that chief diversity officers (CDOs) are responsible for changing the organizational culture and strategically increasing diversity, equity, and inclusion (DE&I) as a sole individual, when successful change begins with organizational leadership and individual employees as key contributors for change in a global environment. To this end, how CDOs can foster an organizational culture that adheres to inclusive excellence is an emerging strategic priority globally. There is a growing body of literature that addresses the role of the CDO; however, there is a need to understand how this role can strategically introduce an organizational DE&I implementation plan in a global environment. This qualitative systematic review explored peer-reviewed research from several research databases and grey literature ii THE CHIEF DIVERSITY OFFICER identified through a snowballing method in order to develop an understanding of how CDOs can use diversity-themed strategic priorities to create an organizational implementation plan. The research process led to 491 articles published from 2015–2020 being identified. Sixty three articles were included in this study upon a quality appraisal technique being applied. Systems theory, theory of organizational commitment, and transformational leadership theory were combined as a decisional framework to evaluate the research question and guide the research process. Seven themes emerged in this study, using thematic analysis and deductive coding as an analytical strategy that can provide CDOs with guidance on developing and implementing a strategic organizational DE&I plan. Implications for future research are assessed. Keywords: diversity, equity, inclusion, workforce diversity, workplace diversity, organizational culture, business case, chief diversity officer, strategic diversity leadership iii THE CHIEF DIVERSITY OFFICER THE CHIEF DIVERSITY OFFICER IN A GLOBAL ENVIRONMENT: A SYSTEMATIC REVIEW By Don Patrick Trahan, Jr. Dissertation submitted to the School of Business, University of Maryland Global Campus, in partial fulfillment of the requirements for the degree of Doctor of Business Administration 2021 iv THE CHIEF DIVERSITY OFFICER v THE CHIEF DIVERSITY OFFICER © Copyright by Don Patrick Trahan, Jr. 2021 vi THE CHIEF DIVERSITY OFFICER Preface In the 21st century, the chief diversity officer (CDO) is a critical and essential role in the structure of an organization’s executive leadership. Under the aegis of the CDO, organizations can adopt strategic diversity initiatives as a priority in order to maximize their bottom line (i.e., make money, save money, and reach organizational goals). The scope and bandwidth of the role varies drastically from organization to organization. As such, while there are agreed upon standards and competencies outlined for CDOs, there is not a one size fits all framework that has been adopted globally. The organizational accountability, infrastructure, incentives, and resources committed to this role are inconsistent, impacting the manner in which a CDO can use strategic diversity leadership to guide the organizational change process. To address this concern, in this dissertation, I assessed the landscape of literature with a specific focus on how CDOs can use diversity, equity, and inclusion strategies in order to develop and implement an organizational strategic diversity approach in a global environment. This study will assist CDOs and executive leaders with identifying strategies that can be prioritized in order to drive strategic diversity change. vii THE CHIEF DIVERSITY OFFICER Dedication This dissertation is dedicated in loving memory of Drs. Ronald Howard and Mark T. Worthy. Dr. Ron, I would not be Dr. Don without you. When I defended my dissertation, I could hear your voice in my head and your spirit right next to me. It hit me one hour before my defense that I was defending on the eve of the one-year anniversary of your death. Your support and mentorship were invaluable and made me the businessman I am today. I will forever be grateful and blessed because of you! Dr. Worthy, you are directly responsible for how I assess that which I am confronted with, no matter what the situation may be, and it has changed my life. Everything you taught me has come to pass and because of your guidance, I have navigated each situation with ease. I thank you both for guiding me and preparing me for what to expect throughout my academic journey as a young Black scholar. You both believed in me even when I sometimes doubted myself and helped keep my feet grounded with only forward movement in sight. While you are no longer here, your hard work, dedication, and mentorship will live on as I, and the many others you impacted, are committed to paying it forward. Thank you! viii THE CHIEF DIVERSITY OFFICER Acknowledgements I would like to thank everyone who has supported me along this journey. BUT GOD! I am so thankful that I have had the love and support of so many individuals who prayed for me and wanted to see me succeed as I navigated this process for the second time. I am truly honored to be an example of what can be accomplished if you put your mind to something and see it through. Being a Black man with two terminal degrees is an honor and one that I do not take for granted. I look forward to being a beacon of support for those who will follow in my footsteps as I stand on the shoulders of giants and I commit to paying it forward. I would like to thank my dissertation committee for your support throughout this process. Dr. Marbury, your patience and encouragement was invaluable and provided me with the space I needed to see this dissertation project to the end. I will forever be thankful for you guiding me along this journey. Dr. Witz, I thank you for challenging me and providing different perspectives that I could take into consideration as I continue to advance diversity, equity, and inclusion in a global environment. Last but not least, I would like to thank all the members of my cohort for your support. We did it! The University of Maryland Global Campus will forever have a special place in my heart as I continue to chart my unique path personally and professionally. I thank each of you for playing a role in my development as a business scholar-practitioner. To all the scholars still navigating their doctoral journey, see this process through because there is light at the end of the tunnel. No matter what, don’t give up; don’t give in; don’t give out. God bless! ix THE CHIEF DIVERSITY OFFICER Table of Contents ABSTRACT i THE CHIEF DIVERSITY OFFICER IN A GLOBAL ENVIRONMENT: A SYSTEMATIC REVIEW iii Preface vi Dedication vii Table of Contents ix List of Tables xii List of Figures xiii List of Abbreviations xiv Chapter 1: Introduction and Overview of the Business Problem 1 Historical Context, Background and Overview 1 American Politics 3 Diversity in the 21st Century 3 The Impact of Globalization 5 Technology 6 Generational Dynamics 6 The Emergence of the Chief Diversity Officer 7 The New Workplace 8 Managing Diversity 11 Employee Retention 11 The Complexity of Managing Diversity 12 Cultural Dynamics 14 Problem Statement and Significance of the Problem 14 Rationale for the Study 15 The Research Question 16 Definitions 16 Organization of the Dissertation 18 Chapter 2: Scoping Literature Review and Theoretical Frame 19 Diversity Management 19 Legal Sanctions in the Evolution of Diversity 20 Racial Segregation in America 21 Diversity Management Challenges 21 x THE CHIEF DIVERSITY OFFICER Moving Beyond Race and Gender 24 Diversity in the 21st Century 25 Diversification of the Organizational Staff 25 Multinational Management 26 Organizational Culture 27 Organizational Climate 28 Elements of the Organizational Culture 29 Strategic Diversity Leadership 39 The Chief Diversity Officer 41 Strategic Implementation Plan 52 Corporate Social Responsibility 53 Theoretical Framework 54 Systems Theory 54 Theory of Organizational Commitment 55 Transformational Leadership Theory 56 Conceptual Model 57 Chapter Summary 58 Chapter 3: Method 60 Research 61 Qualitative Research 62 Evidence Based Research Framework 63 Search Strategy 68 Search Process 69 Inclusion and Exclusion Criteria 70 Limitations of the Search Strategy 71 Study Selection and Data Extraction 72 Quality Appraisal 72 TAPUPAS 73 Analysis and Synthesis Methodology 74 Method of Synthesis 74 Software for Coding 76 Subject Matter Experts 76 Chapter Summary 78 Chapter 4: Analysis and Findings 79 Review of the Research Question 79 Description of the Data Set 79 Results of the Quality Appraisal of the Data Set 81 Themes 82 Theme 1: The Business Case for Diversity, Equity, and Inclusion in a Global Market 83 Theme 2: Build Diversity, Equity, and Inclusion into Organizational Strategic Priorities 85 Theme 3: Chief Executive Officer as a Champion for Diversity, Equity, and Inclusion 89 xi THE CHIEF DIVERSITY OFFICER Theme 4: Board Accountability for Diversity, Equity, and Inclusion 92 Theme 5: Organizational Learning, Education, and Assessment 93 Theme 6: Recruitment and Retention of Diverse Talent 96 Theme 7: Organizational Staff Participation in Diversity, Equity, and Inclusion Processes 97 Chapter Summary 99 Chapter 5: Conclusions and Implications 101 Review of the Research 101 Answer to the Research Question 102 Business Implications 108 Limitations of the Study 110 Areas for Future Research 111 Final Summary and Conclusion 113 References 116 Appendix A: Databases Used 137 Appendix B: Codes Used 138 xii THE CHIEF DIVERSITY OFFICER List of Tables Table 1. CIMO Framework 68 Table 2. Key Search Terms 70 Table 3. Inclusion/ Exclusion 71 Table 4. Themes and Descriptions 83 xiii THE CHIEF DIVERSITY OFFICER List of Figures Figure 1. Conceptual Model Displaying the Interconnection between DE&I as an Organization Strategic Priority and the Change Process 58 Figure 2. PRISMA Diagram Outlines the Search Strategy 81 xiv THE CHIEF DIVERSITY OFFICER List of Abbreviations CDO: Chief Diversity Officer CEO: Chief Executive Officer CFO: Chief Financial Officer CHRO: Chief Human Resources Officer CIMO: Context, intervention, mechanism, outcome COO: Chief Operating Officer CSR: Corporate social responsibility DE&I: Diversity, equity, and inclusion EVP: Executive Vice President PRISMA: Preferred reporting items for systematic reviews and meta-analyses SME: Subject matter experts SR: Systematic review TAPUPAS: Transparency, accuracy, purposivity, utility, propriety, accessibility, and specificity VP: Vice President 1 THE CHIEF DIVERSITY OFFICER Chapter 1: Introduction and Overview of the Business Problem Historical Context, Background and Overview Identifying ways to maximize the benefits of workforce and workplace diversity, equity, and inclusion (DE&I) is a significant business problem (Ali et al., 2015; Kim, 2006; Stevenson, 2014; Williams, 2013; Williams & Wade-Golden, 2013). To understand the significance and complexity of DE&I in businesses in the 21st century, one needs to evaluate the historical context that has shaped the organizational culture in many organizations. Race and/or race relations are one of the most critical cultural factors to assess (Rothstein, 2017; Thomas, 1992). The racialization of people, defined as a system that creates hierarchy based on an individual’s racial background, has had a profound influence on the experiences of historically marginalized individuals, particularly in the United States (Barnett & Felten, 2016; Hays, 2016; Rothstein, 2017; Thomas, 1992; Williams, 2013). When the historical context (e.g., colonization) is taken into consideration globally, many individuals from marginalized backgrounds are still experiencing discrimination and forms of prejudice based on their race, ethnic heritage, or other cultural factors (e.g., gender, sexual orientation, religious/spiritual beliefs). The perceived discrimination creates a dynamic wherein individuals present with vastly different lived experiences in the workplace. One might be inclined to argue that the 21st century is well beyond previous periods of time once marked by racial and gender discrimination as significant shifts have been witnessed (e.g., the election of the first Black President and Vice President). However, history matters, and there are consequences for the actions that have taken place in the past (Rothstein, 2017; Sarpong, 2017; Smith, 2018; Walters, 2012). For example, following the 13th Amendment passed in 1865 in the United States, enslaved African people were legally freed and slavery nor 2 THE CHIEF DIVERSITY OFFICER involuntary servitude was permitted to exist in the United States or any place subject to its jurisdiction (Rothstein, 2017; Thomas, 1992). While this was a significant milestone in American history, it also presented a new level of uncertainty, cultural dynamics, and expectations for individuals from such backgrounds. Newly freed descendants of enslaved Africans were expected to navigate in an environment where their ancestors were treated as property, and they were systematically and strategically disenfranchised for approximately 400 years (Rothstein, 2017; Smith, 2018; Walters, 2012). “After the Civil War, liberated slaves dispersed throughout the United States, seeking work and to escape the violence of the post-war South” (Rothstein, 2017, p. 39). Such systemic barriers did not end following this period in American history. For approximately an additional 100 years, the United States witnessed a multitude of racial inequities governed through policy and legal ramifications such as Jim Crow, Redlining, Brown v. Board of Education, and the Civil Rights Movement. According to Rothstein (2017), de facto segregation was and is directly connected to suppressed incomes driven by the workplace culture. African Americans and other marginalized communities were forced to isolate themselves because they could not afford to live in communities that were predominately Caucasian. This was directly related to their low incomes dictated by access to opportunities in organizations across the United States (Smith, 2018; Walters, 2012). Fast forward to present day, institutional racism and systemic barriers still exist, which has led to the contemporary Black Lives Matter movement. Rothstein (2017) argued that racial segregation will persist (e.g., educationally and financially) until equity is prioritized in organizations and the economy at-large. 3 THE CHIEF DIVERSITY OFFICER American Politics For many, the presidency of Barack Obama may has been viewed as the first example of a true post racial society in the United States due to President Obama being the first Black man to serve in that office. One of the premises of President Obama’s campaign was “hope”, which spoke to many Americans in a different way as it appeared that change would finally occur in a nation with a dark history of race relations (Zelizer, 2018). However, the election and presidency of Donald Trump unveiled a mask that many Americans still wear and has been marked by overt racial tensions both domestically and internationally (Clayton et al., 2019). Make America Great Again created a movement that saw a surge in groups that believed that America would return to a period of time wherein they felt empowered (Blumenthal, 2021; Exec. Order 13985, 2021; Lerer, 2020). On January 6, 2021, this desire was elevated to a level that received global recognition. Domestic terrorists and supporters of Donald Trump stormed the United States Capitol in protest of the results of the Electoral College being certified by the 117 members of the United States Congress, thereby officially electing Joe Biden as the 46th President of the United States. This day was marked with historical racial imagery and epithets being chanted by those who gathered during what is now defined as an insurrection. This day was a reminder that the United States is far from a post racial society and remains divided (NPR, 2021; Proceedings of the United States Senate in the Impeachment Trial of Donald John Trump, 117 Cong., 2021). This means that the workforce and workplace will continue to be impacted accordingly. Diversity in the 21st Century Organizations are challenged on how to foster an organizational culture that is inclusive, while respecting the historical and current racial and cultural barriers that exist in the workplace 4 THE CHIEF DIVERSITY OFFICER (Adler, 2018; Daniels, 2020; Williams, 2013). A common misconception that must be demystified is that racial inequities and workplace discrimination is limited to Black Americans and Caucasians (Barnett & Felten, 2016; Plummer, 2018; Thomas, 1992). Yes, Black Americans and Caucasians have an adverse history, but such dynamics are not limited to these communities. There are various cultural factors that have the potential to create a workplace environment that is not inclusive or divided based on lived experiences. For example, Indigenous communities experience elevated levels of anxiety, depression, and generational trauma when they reflect upon the fact that their land was stolen, thereby evoking elements of intergenerational trauma on this community (Chavez & Longerbeam, 2016; Hays, 2016; O’Nell et al., 2010). Moreover, many members of the lesbian, gay, bisexual, and transgender (LGBT) communities present with fear of being outed or navigating in an environment that is not support (Boerties, 2012; Hollis & McCalla, 2013; Sengar et al., 2020). Simultaneously, this historical context can create extreme discomfort, denial, and defensiveness among Caucasian people when they are confronted with elements of racial inequality and injustice, referred to as White fragility (DiAngelo, 2020). While the examples mentioned do not capture the grim history of race relations in the United States at-large, and racial dynamics are not limited to these communities, this presents an understanding of the manner in which many communities may enter the work environment. Over the last several decades, organizations have implemented a number of DE&I initiatives in order to meet the needs of a challenging, complex, and ever-changing diverse workforce. While initial initiatives (e.g., affirmative action and equal employment opportunity) were directly connected to race and/or race relations as a result of the historical context aforementioned, in contemporary society, organizations have seen a shift in the composition of 5 THE CHIEF DIVERSITY OFFICER the lenses of the workforce (e.g., gender, generational differences, race, sexuality, geographical location, and national origin). For example, generational dynamics have reshaped the composition of the workforce and workplace environment. According to Hershatter and Epstein (2010), college graduates from the millennial generation entered the workforce in the summer of 2004. This generation has surpassed the baby boomers, becoming the largest generation in the workforce (Hershatter & Epstein, 2010). This is significant as millennials had access to opportunities that previous generations (e.g., traditionalist, baby boomers, and generation X) did not have access to, namely technology. This means that the manner in which work is assessed and approached varies more than that of previous workforces. For some, millennials are viewed as a generation that is armed with tools to reimagine how to address problems that emerge globally (e.g., economic and geopolitical). However, others view this generation as “young people who have been so over-indulged and protected that they are incapable of handling the most mundane task without guidance or handholding” (Hershatter & Epstein, 2010, p. 211). Regardless of the outlook, the composition of the workforce has shifted as a result of there being five generations working together with vastly different lived experi

Simulation of electrophoretic stretching of DNA in a microcontraction using an obstacle array for conformational preconditioning

Recently our group has reported experiments using an obstacle array to precondition the conformations of DNA molecules to facilitate their stretch in a microcontraction. Based upon previous successes simulating electrophoretic stretching in microcontractions without obstacles, we use our simulation model to study the deformation of DNA chains in a microcontraction preceded by an array of cylindrical obstacles. We compare our data to the experimental results and find good qualitative, and even quantitative, agreement concerning the behavior of the chains in the array; however, the simulations overpredict the mean stretch of the chains as they leave the contraction. We examine the amount of stretch gained between leaving the array and reaching the end of the contraction and speculate that the differences seen are caused by nonlinear electrokinetic effects that become important in the contraction due to a combination of field gradients and high field strengths.Singapore-MIT AllianceNational Institute of Biomedical Imaging and Bioengineering (U.S.) (Award No. T32EB006348

Preface to Special Topic: Papers from the 82nd American Chemical Society Colloid and Surface Science Symposium, Raleigh, North Carolina, 2008

This Special Topic section of Biomicrofluidics contains original contributions that were presented at the 82nd Colloid and Surface Science Symposium, which took place on 15–18 June 2008 at North Carolina State University. The Symposium covered a wide range of topics that are relevant to the fundamentals of fluidics and their application to biological systems

Routine serial echocardiography in systolic heart failure: is it time for the heart failure guidelines to change?

The authors sought to obtain objective evidence for impacting the American College of Cardiology Heart Failure Guidelines for the routine use of serial echocardiography by assessing the reliability of the use of clinician-assessed patient symptoms and New York Heart Association (NYHA) functional classification compared with ejection fraction (EF) measured by echocardiography. A prospective study in 256 patients with systolic heart failure (HF) enrolled into an HF disease management program with EF ≤40% and at least 2 annual echocardiograms were included. Only 86 of 256 (33.5%) patients were correctly classified by NYHA class as showing improvement, no change, or deterioration as compared with echocardiographic assessments. Patients whose NYHA class showed no change between echocardiograms had the lowest survival rate. Quantification in patient's status with NYHA classification is not always a reliable assessment to evaluate prognosis and guide medical therapy for patients with systolic HF

Inflammation is associated with the remodeling of calcific aortic valve disease

Calcific aortic valve disease (CAVD) is the most frequent heart valve disorder. Studies indicate that mineralization of the aortic valve may be related to the inflammatory process. However, no clear evidence has been given regarding clinical evolution of aortic stenosis and the inflammatory process within the aortic valve. Aortic valves excised from 285 patients with CAVD undergoing aortic valve replacement were analyzed for the presence of chronic inflammatory infiltrates, and those findings were related to the hemodynamic severity of aortic stenosis. In a subset of 57 patients, in whom additional valvular tissue and the clinical progression rate of aortic stenosis were available, the density of leukocytes was determined as well as the number of TNF-a transcripts. Histological analyses revealed that in 81 (28.4 %) patients, the presence of chronic inflammatory infiltrates was documented within CAVD tissue, which was characterized by the existence of a cluster of cells as well as the presence of neovascularisation and osseous metaplasia. The presence of an inflammatory process within the CAVD tissue was independently related to the remodeling process and the peak transaortic gradient. In addition, the density of leukocytes within CAVD tended to correlate (r¿=¿0.25, p¿=¿0.05) with the progression rate of aortic stenosis. Dense inflammatory infiltrate within CAVD is associated with an active remodeling process, the severity of aortic stenosis, and the hemodynamic progression rate

Lipoprotein lipase in aortic valve stenosis is associated with lipid retention and remodelling

Background: Calcific aortic valve disease (CAVD) is a chronic disorder characterized by a fibrocalcific remodelling. It is suspected that lipid retention within the aortic valve may be one important mechanism participating to aortic valve remodelling. Lipoprotein lipase (LPL) is implicated in lipid metabolism and may play a role in lipid retention within the aortic valve. Methods: In 57 patients, CAVD were analysed for the expression of LPL by q-PCR and immunohistochemistry. Expression of oxidized-LDL (ox-LDL) and decorin was also documented. In addition, a complete blood profile, including the size of LDL and high-density lipoprotein (HDL) particles, were performed to find associations between the blood lipid profile and expression of ox-LDL and LPL within CAVD. Results: Immunohistochemistry studies revealed that LPL was expressed in stenotic aortic valves as a diffuse staining and also in dense cellular areas where macrophages were abundant. Expression of LPL co-localized with decorin and ox-LDL. In turn, valves with higher amount of ox-LDL had elevated number of LPL transcripts. In addition, we documented that the small, dense HDL phenotype was associated with an elevated amount of ox-LDL and LPL transcripts within CAVD. Furthermore, expression of LPL was associated with several indices of fibrocalcific remodelling of the aortic valve. Conclusion: Expression of LPL within CAVD is related to the amount of ox-LDL, which is, in turn, associated with the small, dense HDL phenotype. Lipid retention associated with smaller HDL particles may participate in the expression of LPL, whereby a fibrocalcific remodelling of the aortic valve is promoted

Sex-related discordance between aortic valve calcification and hemodynamic severity of aortic stenosis : is valvular fibrosis the explanation?

Rationale: Calcific aortic stenosis (AS) is characterized by calcium deposition in valve leaflets. However, women present lower aortic valve calcification (AVC) loads than men for the same AS hemodynamic severity. Objective: We thus aimed to assess sex-differences in aortic valve fibro-calcific remodelling. Methods and Results: One hundred and twenty-five patients underwent Doppler-echocardiography and multidetector-computed-tomography within 3 months prior to aortic valve replacement. Explanted stenotic tricuspid aortic valves were weighed and fibrosis degree was determined. Sixty-four men and 39 women were frequency-matched for age, body mass index (BMI), hypertension, renal disease, diabetes, and AS severity. Mean age was 75±9years, mean gradient (41±18mmHg) and indexed aortic valve area (0.41±0.12cm2/m2) were similar between men and women (all p=0.18). Median AVC (1973[1124-3490]AU) and mean valve weight (2.36±0.99g) were lower in women compared to men (both p<0.0001). AVC density correlated better with valve weight in men (r2=0.57; p<0.0001) than in women (r2=0.26; p=0.0008). After adjustment for age, BMI, AVC density and aortic annulus diameter, female sex was an independent risk factor for higher fibrosis score in AS valves (p=0.003). Picrosirius red staining of explanted valves showed greater amount of collagen fibers (p=0.01) and Masson's trichrome staining revealed a greater proportion of dense connective tissue (p=0.02) in women compared to men. Conclusions: In this series with tricuspid aortic valve and similar AS severity, women have less valvular calcification but more fibrosis compared to men. These findings suggest that the pathophysiology of the disease and thus potential targets for drug development may be different according to sex