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  1. Book ; Online: Estimating the matrix $p \rightarrow q$ norm

    Guth, Larry / Maldague, Dominique / Urschel, John

    2023  

    Abstract: The matrix $p \rightarrow q$ norm is a fundamental quantity appearing in a variety of areas of mathematics. This quantity is known to be efficiently computable in only a few special cases. The best known algorithms for approximately computing this ... ...

    Abstract The matrix $p \rightarrow q$ norm is a fundamental quantity appearing in a variety of areas of mathematics. This quantity is known to be efficiently computable in only a few special cases. The best known algorithms for approximately computing this quantity with theoretical guarantees essentially consist of computing the $p\to q$ norm for $p,q$ where this quantity can be computed exactly or up to a constant, and applying interpolation. We analyze the matrix $2 \to q$ norm problem and provide an improved approximation algorithm via a simple argument involving the rows of a given matrix. For example, we improve the best-known $2\to 4$ norm approximation from $m^{1/8}$ to $m^{1/12}$. This insight for the $2\to q$ norm improves the best known $p \to q$ approximation algorithm for the region $p \le 2 \le q$, and leads to an overall improvement in the best-known approximation for $p \to q$ norms from $m^{25/128}$ to $m^{3 - 2 \sqrt{2}}$.
    Keywords Computer Science - Data Structures and Algorithms ; Mathematics - Functional Analysis ; 15A60 ; 65F35 ; 68W25
    Subject code 518
    Publishing date 2023-11-13
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Evaluation of seasonal influences on adrenocorticotropic hormone response to the thyrotropin-releasing hormone stimulation test and its accuracy for diagnosis of pituitary pars intermedia dysfunction.

    Adams, A A / Siard-Altman, M H / Reedy, S E / Barker, D / Elzinga, S / Sanz, M G / Urschel, K / Ireland, J L

    Veterinary journal (London, England : 1997)

    2023  Volume 300-302, Page(s) 106035

    Abstract: Pituitary pars intermedia dysfunction (PPID) is an age-related neurodegenerative disorder, affecting >20 % of older horses. There is a need for improved endocrine tests for early disease detection, and the thyrotropin-releasing hormone (TRH) stimulation ... ...

    Abstract Pituitary pars intermedia dysfunction (PPID) is an age-related neurodegenerative disorder, affecting >20 % of older horses. There is a need for improved endocrine tests for early disease detection, and the thyrotropin-releasing hormone (TRH) stimulation test has been recommended for diagnosis of early or mild cases. However, it is currently not recommended for year-round use due to marked seasonal variability. The aims of this cohort study were to evaluate effects of month and season on adrenocorticotropic hormone (ACTH) responses to TRH stimulation and to derive monthly cut-offs for PPID diagnosis. Sixty-three horses were assigned to control (n = 17), subclinical PPID (n = 21) and clinical PPID (n = 25) groups, based on a composite reference standard that combined clinical history and examination findings with endocrine test results. TRH stimulation tests were performed monthly for a 12-month period. Circannual changes were evaluated with one- and two-way repeated-measures analysis of variance and receiver operating characteristic curve analysis was used to derive cut-off values for basal and TRH-stimulated ACTH. TRH-stimulated ACTH concentrations were lowest in February-May and highest in August-October. Specificity of both basal and 30 min post-TRH ACTH was generally higher than sensitivity, and TRH stimulation had improved diagnostic accuracy compared to basal ACTH, although its sensitivity was not significantly greater year-round. TRH stimulation tests yielded considerably more positive results than basal ACTH in the subclinical group, but few additional positive results in clinical PPID cases. There were large differences between cut-offs that maximised sensitivity or specificity for TRH-stimulated ACTH, highlighting the importance of considering clinical presentation alongside test results in diagnostic decision-making.
    MeSH term(s) Horses ; Animals ; Adrenocorticotropic Hormone/pharmacology ; Thyrotropin-Releasing Hormone/pharmacology ; Seasons ; Cohort Studies ; Pituitary Diseases/diagnosis ; Pituitary Diseases/veterinary ; Pituitary Gland, Intermediate/metabolism ; Horse Diseases/diagnosis
    Chemical Substances Adrenocorticotropic Hormone (9002-60-2) ; Thyrotropin-Releasing Hormone (5Y5F15120W)
    Language English
    Publishing date 2023-10-05
    Publishing country England
    Document type Journal Article
    ZDB-ID 428614-5
    ISSN 1532-2971 ; 0372-5545 ; 1090-0233
    ISSN (online) 1532-2971
    ISSN 0372-5545 ; 1090-0233
    DOI 10.1016/j.tvjl.2023.106035
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Book ; Online: Treating Tumors that Move with Respiration

    Urschel, Harold C. / Kresl, John J. / Luketich, James D. / Papiez, Lech / Schulz, Raymond A. / Timmerman, Robert D.

    2007  

    Author's details edited by Harold C. Urschel, John J. Kresl, James D. Luketich, Lech Papiez, Robert D. Timmerman, Raymond A. Schulz
    Keywords Biomedical engineering ; Oncology ; Pneumology ; Radiology, Medical ; Radiotherapy ; Surgery
    Language English
    Publisher Springer-Verlag Berlin Heidelberg
    Publishing place Berlin, Heidelberg
    Document type Book ; Online
    HBZ-ID TT050387782
    ISBN 978-3-540-69885-2 ; 978-3-540-69886-9 ; 3-540-69885-X ; 3-540-69886-8
    DOI 10.1007/978-3-540-69886-9
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  4. Article ; Online: Prospective examination of HLA sensitization after VAD implantation in children and adults.

    Townsend, Madeleine / Pidborochynski, Tara / Cantor, Ryan S / Khoury, Michael / Campbell, Patricia / Halpin, Anne / Urschel, Simon / Kim, Daniel / Nahirniak, Susan / West, Lori J / Buchholz, Holger / Conway, Jennifer

    Transplant immunology

    2023  Volume 80, Page(s) 101892

    Abstract: Background: Ventricular assist devices (VADs) have improved survival to heart transplantation (HTx). However, VADs have been associated with development of antibodies against human leukocyte antigen (HLA-Ab) which may limit the donor pool and decrease ... ...

    Abstract Background: Ventricular assist devices (VADs) have improved survival to heart transplantation (HTx). However, VADs have been associated with development of antibodies against human leukocyte antigen (HLA-Ab) which may limit the donor pool and decrease survival post-HTx. Since HLA-Ab development after VAD insertion is poorly understood, the purpose of this prospective single-center study was to quantify the incidence of and evaluate risk factors for HLA-Ab development across the age spectrum following VAD implantation.
    Methods: Adult and pediatric patients undergoing VAD placement as bridge to transplant or transplant candidacy between 5/2016 and 7/2020 were enrolled. HLA-Ab were assessed pre-VAD and at 1-, 3-, and 12-months post-implant. Factors associated with HLA-Ab development post-VAD implant were explored using univariate and multivariate logistic regression.
    Results: 15/41 (37%) adults and 7/17 (41%) children developed new HLA-Ab post-VAD. The majority of patients (19/22) developed HLA-Ab within two months of implant. New class I HLA-Ab were more common (87% adult, 86% pediatric). Prior pregnancy was strongly associated with HLA-Ab development in adults post-VAD (HR 16.7, 95% CI 1.8-158, p = 0.01). Of the patients who developed new HLA-Ab post-VAD, in 45% (10/22) the HLA-Ab resolved while in 55% (12/22) the HLA-Ab persisted.
    Conclusion: More than one-third of adult and pediatric VAD patients developed new HLA-Ab early after VAD implant with the majority having class I antibodies. Prior pregnancy was strongly associated with post-VAD HLA-Ab development. Further studies are needed to predict regression or persistence of HLA-Ab developed post-VAD, to understand modulation of individuals' immune responses to sensitizing events, and to determine whether transiently detected HLA-Ab post-VAD recur and have long-term clinical impact post-heart transplantation.
    Language English
    Publishing date 2023-07-05
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 1160846-8
    ISSN 1878-5492 ; 0966-3274
    ISSN (online) 1878-5492
    ISSN 0966-3274
    DOI 10.1016/j.trim.2023.101892
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Differential effect of two dietary protein sources on time course response of muscle anabolic signaling pathways in normal and insulin dysregulated horses.

    Loos, Caroline M M / McLeod, Kyle R / Vanzant, Eric S / Stratton, Sophie A / Bohannan, Adam D / Coleman, Robert J / van Doorn, David A / Urschel, Kristine L

    Frontiers in veterinary science

    2022  Volume 9, Page(s) 896220

    Abstract: The objective of the study was to characterize the temporal changes of phosphorylation patterns of mTOR signaling proteins in response to two dietary protein sources in insulin dysregulated (ID, ...

    Abstract The objective of the study was to characterize the temporal changes of phosphorylation patterns of mTOR signaling proteins in response to two dietary protein sources in insulin dysregulated (ID,
    Language English
    Publishing date 2022-08-01
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2834243-4
    ISSN 2297-1769
    ISSN 2297-1769
    DOI 10.3389/fvets.2022.896220
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Human Leukocyte Antigen Antibody Sampling in Ventricular Assist Device Recipients: Are We Talking?

    Khoury, Michael / Pidborochynski, Tara / Halpin, Anne / Campbell, Patricia / Urschel, Simon / Kim, Daniel / West, Lori / Buchholz, Holger / Conway, Jennifer

    Transplantation proceedings

    2021  Volume 53, Issue 7, Page(s) 2377–2381

    Abstract: Background: Ventricular assist devices (VADs) are commonly used as a bridge to transplantation but may yield HLA sensitization. We evaluated the prevalence of HLA antibody (Ab) sampling pre- and post-VAD placement in pediatric and adult patients and ... ...

    Abstract Background: Ventricular assist devices (VADs) are commonly used as a bridge to transplantation but may yield HLA sensitization. We evaluated the prevalence of HLA antibody (Ab) sampling pre- and post-VAD placement in pediatric and adult patients and notification of VAD status to the HLA laboratory.
    Methods: All pediatric and adult patients who received a first-time VAD between 2005 and 2013 were included in this single-center retrospective review. Data were collected from the University of Alberta Hospital histocompatibility laboratory's information system and a local VAD database.
    Results: In total, 106 patients were included (40 pediatric, median 3.0 years [interquartile range, 0.3-10.7]; 66 adult, 55.0 years [46.8-61.2]). HLA Ab sampling within 1-month pre-VAD occurred in 70% of pediatric and 79% of adult recipients (P = .215). Testing within 1 month of VAD placement occurred in 89% of pediatric and 67% of adult recipients (P = .012). For those with HLA Ab sampling within 30 days postimplant, notification to the HLA laboratory of VAD status occurred in 19 of 27 (70%) pediatric and 24 of 33 (73%) adult patients (P = .533). Of patients transplanted post VAD with HLA Ab samples collected, 12 of 28 (43%) and 13 of 38 (34%) adult recipients did not have notification of VAD status to the HLA laboratory (P = .322).
    Conclusions: There were inconsistencies in HLA Ab sampling and communication to the HLA laboratory surrounding VAD placement. Standardization of both HLA Ab assessment frequency after VAD implantation and communication regarding changes in clinical status and the occurrence of key sensitizing events such as VAD placement are imperative as patients await transplantation.
    MeSH term(s) Adult ; Antibodies ; Child ; HLA Antigens ; Heart Failure ; Heart Transplantation ; Heart-Assist Devices ; Humans ; Retrospective Studies
    Chemical Substances Antibodies ; HLA Antigens
    Language English
    Publishing date 2021-08-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 82046-5
    ISSN 1873-2623 ; 0041-1345
    ISSN (online) 1873-2623
    ISSN 0041-1345
    DOI 10.1016/j.transproceed.2021.07.025
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Genetic Contribution to End-Stage Cardiomyopathy Requiring Heart Transplantation.

    Kim, Yuri / Gunnarsdóttir, Oddný Brattberg / Viveiros, Anissa / Reichart, Daniel / Quiat, Daniel / Willcox, Jon A L / Zhang, Hao / Chen, Huachen / Curran, Justin J / Kim, Daniel H / Urschel, Simon / McDonough, Barbara / Gorham, Joshua / DePalma, Steven R / Seidman, Jonathan G / Seidman, Christine E / Oudit, Gavin Y

    Circulation. Genomic and precision medicine

    2023  Volume 16, Issue 5, Page(s) 452–461

    Abstract: Background: Many cardiovascular disorders propel the development of advanced heart failure that necessitates cardiac transplantation. When treatable causes are excluded, studies to define causes are often abandoned, resulting in a diagnosis of end-stage ...

    Abstract Background: Many cardiovascular disorders propel the development of advanced heart failure that necessitates cardiac transplantation. When treatable causes are excluded, studies to define causes are often abandoned, resulting in a diagnosis of end-stage idiopathic cardiomyopathy. We studied whether DNA sequence analyses could identify unrecognized causes of end-stage nonischemic cardiomyopathy requiring heart transplantation and whether the prevalence of genetic causes differed from ambulatory cardiomyopathy cases.
    Methods: We performed whole exome and genome sequencing of 122 explanted hearts from 101 adult and 21 pediatric patients with idiopathic cardiomyopathy from a single center. Data were analyzed for pathogenic/likely pathogenic variants in nuclear and mitochondrial genomes and assessed for nonhuman microbial sequences. The frequency of damaging genetic variants was compared among cardiomyopathy cohorts with different clinical severity.
    Results: Fifty-four samples (44.3%) had pathogenic/likely pathogenic cardiomyopathy gene variants. The frequency of pathogenic variants was similar in pediatric (42.9%) and adult (43.6%) samples, but the distribution of mutated genes differed (
    Conclusions: Pathogenic variants and viral myocarditis were identified in 45.9% of patients with unexplained end-stage cardiomyopathy. Damaging gene variants are significantly more frequent among transplant compared with patients with ambulatory cardiomyopathy. Genetic analyses can help define cause of end-stage cardiomyopathy to guide management and risk stratification of patients and family members.
    MeSH term(s) Adult ; Humans ; Child ; Cardiomyopathies/genetics ; Cardiomyopathies/pathology ; Cardiomyopathy, Dilated/genetics ; Cardiomyopathy, Dilated/surgery ; Cardiomyopathy, Dilated/diagnosis ; Heart Transplantation ; Heart Failure/diagnosis
    Language English
    Publishing date 2023-09-28
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ISSN 2574-8300
    ISSN (online) 2574-8300
    DOI 10.1161/CIRCGEN.123.004062
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Clinical presentation, genetic etiology and outcome associated with fetal cardiomyopathy: comparison of two eras.

    Trakmulkichkarn, T / Ghadiry-Tavi, R / Fruitman, D / Niederhoffer, K Y / Caluseriu, O / Lauzon, J L / Wewala, G / Hornberger, L K / Urschel, S / Conway, J / McBrien, A

    Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology

    2021  Volume 59, Issue 3, Page(s) 325–334

    Abstract: Objective: To assess the rate and type of genetic diagnosis and clinical outcome of cases of fetal cardiomyopathy (CM) during two eras, in order to examine the impact of advanced genetic testing and improved perinatal management strategies.: Methods: ...

    Abstract Objective: To assess the rate and type of genetic diagnosis and clinical outcome of cases of fetal cardiomyopathy (CM) during two eras, in order to examine the impact of advanced genetic testing and improved perinatal management strategies.
    Methods: All diagnoses of fetal CM in Alberta, Canada, encountered between 2003 and 2019, were reviewed retrospectively. Genetic, cardiac and non-cardiac diagnoses and clinical outcome were documented. Cases with CM secondary to extracardiac pathology and maternal conditions were excluded. Cases diagnosed in the earlier era of the study period (2003-2012) were compared with those diagnosed in the later era (2013-2019).
    Results: Thirty-eight cases of fetal CM met the inclusion criteria. Median gestational age (GA) at diagnosis was 22.8 (range, 13.4-37.4) weeks. Associated structural heart disease was present in 39% (15/38) of cases and 24% (9/38) had arrhythmia. Hydrops was identified in 29% (11/38) of cases at presentation, and a further 18% (7/38) developed hydrops later in gestation. Twenty-six percent (10/38) of cases underwent termination of pregnancy and 24% (9/38) had intrauterine death. Of liveborn cases, neonatal death occurred in 16% (3/19), late death occurred in 21% (4/19) and 63% (12/19) were alive at the last follow-up. Excluding cases that had termination of pregnancy and those with a liveborn infant who received planned palliative care, the rate of neonatal survival was higher in the later compared with the earlier era (69% (11/16) vs 45% (5/11)), although the difference was not statistically significant (P = 0.26). A genetic etiology was confirmed in 39% (15/38) of cases and strongly suspected in 24% (9/38). A significantly higher proportion of cases had a confirmed or strongly suspected genetic etiology in the later era compared with in the earlier era (76% (19/25) vs 38% (5/13); P = 0.04).
    Conclusions: In the recent era, a higher proportion of fetal CM cases had a confirmed or strongly suspected genetic etiology than reported previously. Based on comparison with older series, modern perinatal management strategies may not have a significant impact on neonatal survival in cases of fetal CM; however, a larger study would be better powered to detect more subtle differences. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
    MeSH term(s) Cardiomyopathies/genetics ; Edema ; Female ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Pregnancy ; Pregnancy Outcome ; Retrospective Studies ; Ultrasonography, Prenatal
    Language English
    Publishing date 2021-06-22
    Publishing country England
    Document type Journal Article
    ZDB-ID 1073183-0
    ISSN 1469-0705 ; 0960-7692
    ISSN (online) 1469-0705
    ISSN 0960-7692
    DOI 10.1002/uog.23713
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  9. Article ; Online: Impact of race and health coverage on listing and waitlist mortality in pediatric cardiac transplantation.

    Bansal, Neha / Lal, Ashwin K / Koehl, Devin / Cantor, Ryan S / Kirklin, James K / Ravekes, William J / Auerbach, Scott R / Baker-Smith, Carissa M / Cabrera, Antonio G / Amdani, Shahnawaz / Urschel, Simon

    The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation

    2022  Volume 42, Issue 6, Page(s) 754–764

    Abstract: Background: Social factors like race and insurance affect transplant outcomes. However, little is known in pediatric heart transplantation. We hypothesized that race and insurance coverage impact listing and waitlist outcomes across eras.: Methods: ... ...

    Abstract Background: Social factors like race and insurance affect transplant outcomes. However, little is known in pediatric heart transplantation. We hypothesized that race and insurance coverage impact listing and waitlist outcomes across eras.
    Methods: Data from the Pediatric Heart Transplant Society multi-center registry prospectively collected between January 1, 2000-December 31, 2019 were analyzed. Patients were divided by race as Black, White and other and by insurance coverage at listing (US governmental, US private and non-US single payer systems (UK, Canada). Clinical condition at listing and waitlist outcomes were compared across races and insurance coverages. Categorical variables were compared using a chi-square test and continuous variables using the Wilcoxon rank sum test. Risk factors for waitlist mortality were examined using multiphase parametric hazard modeling. A sensitivity analysis using parametric hazard explored the interaction between race and insurance.
    Results: At listing, compared to Whites (n = 5391) and others (n = 1167), Black patients (n = 1428) were older, more likely on US governmental insurance and had cardiomyopathy as the predominant diagnosis (p < 0.0001). Black patients were more likely to be higher status at listing, in hospital, on inotropes or a ventricular assist device (p < 0.0001). Black patients had significantly shorter time on the waitlist compared to other races (p < 0.0001) but had higher waitlist mortality (p = 0.0091), driven by the earlier era (2000-2009) (p = 0.0005), most prominently within the US private insurance cohort (p = 0.015). Outcomes were not different in other insurance cohorts or in the recent era (2010-2019).
    Conclusion: Black children are older and sicker at the time of listing, deteriorate more often and face a higher wait list mortality, despite a shorter waitlist period and favorable clinical factors, with improvement in the recent era associated with the recent US healthcare reforms. The social construct of race appears to disadvantage Black children by limiting referral, consideration or access to pediatric cardiac transplantation.
    MeSH term(s) Humans ; Child ; Heart Transplantation ; Risk Factors ; Registries ; Waiting Lists ; Insurance Coverage ; Retrospective Studies
    Language English
    Publishing date 2022-12-08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1062522-7
    ISSN 1557-3117 ; 1053-2498
    ISSN (online) 1557-3117
    ISSN 1053-2498
    DOI 10.1016/j.healun.2022.12.002
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: [No title information]

    Nicholas, David B / Zulla, Rosslynn T / Conlon, Olivia / Dimitropoulos, Gina / Urschel, Simon / Rapoport, Adam / Katz, Sherri Lynne / Bruce, Aisha / West, Lori J / Belletrutti, Mark / Cullen, Emma / Zwaigenbaum, Lonnie

    Paediatrics & child health

    2022  Volume 27, Issue Suppl 2, Page(s) S115–S122

    Title translation Les effets de la pandémie de COVID-19 sur la santé mentale des enfants atteints de problèmes de santé physique ou d’incapacités, des familles et des professionnels de la santé.
    Language French
    Publishing date 2022-09-08
    Publishing country England
    Document type Journal Article ; Comment
    ZDB-ID 2106767-3
    ISSN 1918-1485 ; 1205-7088
    ISSN (online) 1918-1485
    ISSN 1205-7088
    DOI 10.1093/pch/pxac009
    Database MEDical Literature Analysis and Retrieval System OnLINE

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