196,021 research outputs found
Improvement of the diagnosis and management of cystic tumors of the pancreas
No full textPancreatic cancer is on its course on becoming the second cause of cancer related mortality. Although improvements have been made in the treatment arsenal, still only a minority of patients are able to receive treatment with curative intention. This can be attributed to the fact that most of the pancreatic cancers are diagnosed at a later stage when curative therapy is no longer possible. Thus, efforts are being made to find pancreatic cancer and its precursor lesions at an earlier stage. Intraductal papillary mucinous neoplasms (IPMN) is the most common type of cystic lesion which has the potential for malignant transformation. Hence, an accurate and early diagnosis of this entity could contribute to reverse the dismal trend of pancreatic cancer.Study I & IIAim: To identify and correlate risk factors for advanced histological findings in IPMN patients. Methods: These were retrospective studies in which patients undergoing resection for IPMN during 2008-2015 (study I) and 2004-2017 (study II) were included. Patients characteristics, radiological and histological data were prospectively collected. Results: One-hundred-fifty-two patients were included in study I and 796 patients in study II. In study I, main pancreatic duct (MPD) dilatation of 6-9.9 mm and >10 mm were associated with an increased risk of advanced IPMN histology, such as high grade dysplasia (HGD) and cancer, at odds of 2.92 (CI 1.38–6.20, p=0.005) and 2.65 (CI 1.12–6.25, p=0.02), respectively. In addition, jaundice and elevated levels of CA 19-9 were also associated with higher risk for HGD/cancer at odds of 15.36 (CI 1.94–121.22, p=0.009) and 4.15 (CI 1.90–9.05, p=0.0003), respectively. These associations remained significant at uni- and multivariable regression analysis. In study II, the results showed MPD-dilatation to be the lone significant variable associated with increased probability of HGD or IPMN-cancer at both uni- and multivariable analysis. MPD dilatation of 5-9.9 mm was associated with odds of 2.74 (CI 1.80–4.16) and 4.42 (CI 2.55–7.66) for HGD and IPMN-cancer respectively. MPD-dilatation over 10 mm was associated with greater odds of 6.57 (CI 3.94–10.98) and 15.07 (CI 8.21–27.65) for HGD and IPMN-cancer, respectively. A 5-7 mm diameter of the MPD was determined as the cut-off value to best discriminate between the lesions with low risk of malignancy to those with a high risk. Conclusions: Even a smaller dilatation of the MPD is associated with increased risk of HGD and IPMN-cancer. Dilatation of the MPD and elevated levels of CA 19-9 are important diagnostic markers of advanced histology, thereby facilitating proper selection of patients most suitable for surgery.Study III & IVAim: To define and validate the metabolic profile of patients with IPMN and serous cystic neoplasm (SCN) and to correlate the metabolite levels to histology and grade of dysplasia. Methods: Plasma and cyst fluid were prospectively collected from patients undergoing resection for IPMN and SCN. Targeted and untargeted analysis of metabolites and lipids species were performed and correlated to histology and clinical parameters. Results: From a cohort of 35 patients in study III and 57 patients in study IV several metabolites and lipids were identified in both cyst fluid and plasma. In study III, the metabolic profile showed significant alterations in the lipid pathways. An integrated metabolomic and lipidomic analysis model was able to discriminate IPMN from SCN up to 100% accuracy. The results in study IV not only validated the results from study III but also found novel metabolites able to discriminate non-cancerous lesions (low-grade IPMN and SCN) from malignant (HGD and cancer). Furthermore, specific metabolites correlated to presence of bacteria sequences in the cyst fluid. Conclusion: Analysis of the metabolic profile in cyst fluid and plasma from IPMN patients has been able to discriminate IPMN from SCN with high accuracy and also to predict the degree of dysplasia within IPMN. This method has shown potential of clinical application which in turn could improve the diagnosis of pancreatic cystic lesions.Study VAim: To investigate the rate of new recurrence and progression of known IPMNs in the remnant pancreas after pancreatic surgery and to investigate if the grade of dysplasia at first histology affects the risk of recurrence. Methods: This was a retrospective study in which patients undergoing an elective partial pancreatic resection between 2008 and 2017 were included. Patients who underwent total pancreatectomy and/or had less than 2 years of follow-up were excluded. Patient characteristics and data of radiology, histology and recurrence was collected prospectively. Clinical significant recurrence was defined as findings resulting in a change in the management of the lesion. Results: Overall 224 patients were included in the study. The overall recurrence rate was 44.6% (100/224), whereas the clinical significant recurrence rate was 30.8% (69/224). Patients older than 65 years presented 4.4 odds (CI 1.5-13.1) of recurrence and patients with “known IPMN left in remnant” had 2.6 odds (CI 1.12-5.9) of recurrence. Patients with LGD and HGD at first histology without concomitant PDAC had a clinical significant recurrence rate of 11.1% (15/135). No differences regarding risk of recurrence could be found when comparing patients with LGD to HGD (HR 1.1 [CI 0.5-2.2]). Conclusion: Patients with LGD and HGD at first histology harbor a not negligible risk of future malignant transformation and should not be overlooked. The risk is further increased if the patient is older and/or have a previously known IPMN in the remnant.The overall conclusion of the thesis is that the included studies have increased the knowledge on several aspects in the diagnosis and management of cystic tumors of the pancreas. A known radiological diagnostic marker, the dilatation of the main pancreatic duct, has been studied where the results show that even smaller dilatations over 5 mm may indicate malignancy. An upcoming field in metabolomics has been applied on pancreatic cystic neoplasms and has shown great potential as a future diagnostic method. Lastly, the post-operative management of IPMN patients has been studied where the results highlight the need for continued clinical surveillance due the risk of recurrence even after surgery.List of scientific papersI. Main pancreatic duct dilation greater than 6 mm is associated with an increased risk of high-grade dysplasia and cancer in IPMN patients. Ateeb Z*, Valente R*, Pozzi-Mucelli RM, Malgerud L, Schlieper Y, Rangelova E, Fernandez-Moro C, Löhr JM, Arnelo U, Del Chiaro M. Langenbecks Arch Surg. 2019 Feb;404(1):31-37. *Equal contribution. https://doi.org/10.1007/s00423-018-1740-8 II. Main Duct Dilatation Is the Best Predictor of High-grade Dysplasia or Invasion in Intraductal Papillary Mucinous Neoplasms of the Pancreas. Del Chiaro M*, Beckman R*, Ateeb Z, Orsini N, Rezaee N, Manos L, Valente R, Yuan C, Ding D, Margonis GA, Yin L, Cameron JL, Makary MA, Burkhart RA, Weiss MJ, He J, Arnelo U, Yu J, Wolfgang CL. Ann Surg. 2020 Dec;272(6):1118-1124. *Equal contribution. https://doi.org/10.1097/SLA.0000000000003174 III. Integrated targeted metabolomic and lipidomic analysis: A novel approach to classifying early cystic precursors to invasive pancreatic cancer. Gaiser RA*, Pessia A*, Ateeb Z*, Davanian H, Fernández Moro C, Alkharaan H, Healy K, Ghazi S, Arnelo U, Valente R, Velagapudi V, Sällberg Chen M, Del Chiaro M. Sci Rep. 2019 Jul 15;9(1):10208. *Equal contribution. https://doi.org/10.1038/s41598-019-46634-6 IV. Metabolic Characterization of Plasma and Cyst Fluid from Cystic Precursors to Pancreatic Cancer Patients Reveal Metabolic Signatures of Bacterial Infection. Morgell A*, Reisz JA*, Ateeb Z, Davanian H, Reinsbach SE, Halimi A, Gaiser R, Valente R, Arnelo U, Del Chiaro M, Chen MS, D'Alessandro A. J Proteome Res. 2021 May 7;20(5):2725-2738. *Equal contribution. https://doi.org/10.1021/acs.jproteome.1c00018 V. Recurrence and progress of IPMN in the remnant pancreas after partial resections. Ateeb Z, Franco SR, Valente R, Ghorbani P, Sparrelid E, Gilg S, Del Chiaro M, Arnelo U. [Manuscript]</p
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
Letter from Cedrick M. Shimo to the Office of Redress Administration, June 4, 1991
No full textA letter from Cedrick M. Shimo to the Office of Redress Administration arguing that John Y. Udaka is entitled to a redress payment.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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