30 research outputs found
Hydronics 102 System Components
Boldt, J., & Keen, J. (2015). Hydronics 102 System Components. ASHRAE Journal, 57(9), 40-48.The article explores the common control devices in closed-loop hydronic systems (HS) namely expansion tanks (ET) and valves. Topics covered include the types of control needed in a hydronic system, the various kinds of ET including compression tanks and bladder tanks, the maximum design pressures for HS, the factors that must be considered when determining the size of a tank including system volume, and the differences between the types of valves including ball, butterfly and globe
Hydronics 101
Holtmeyer, D., Boldt, J., & Keen, J. (2015). Hydronics 101. ASHRAE Journal, 57(9), 8-10The article presents a letter to the editor in response to the story "Hydronics 101" in the May 2015 issue, and provides the authors' response to the comments on their work
Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape
Dunes are present in all the worlds’ big rivers and form critical agents of bedload transport, constitute appreciable sources of bed roughness and flow resistance, and generate stratification that is the most common depositional element of ancient alluvium. Yet our current models of dunes are conditioned by the geometry of bedforms observed in small rivers and laboratory experiments, and in which the downstream leeside angle is often assumed to be at the angle-of-repose. Here we show, using high-resolution bathymetry from a range of the worlds great rivers, that dunes are instead characterized predominantly by low-angle leeside slopes
The DZHK research platform: maximisation of scientific value by enabling access to health data and biological samples collected in cardiovascular clinical studies
The German Centre for Cardiovascular Research (DZHK) is one of the German Centres for Health Research and aims to conduct early and guideline-relevant studies to develop new therapies and diagnostics that impact the lives of people with cardiovascular disease. Therefore, DZHK members designed a collaboratively organised and integrated research platform connecting all sites and partners. The overarching objectives of the research platform are the standardisation of prospective data and biological sample collections among all studies and the development of a sustainable centrally standardised storage in compliance with general legal regulations and the FAIR principles. The main elements of the DZHK infrastructure are web-based and central units for data management, LIMS, IDMS, and transfer office, embedded in a framework consisting of the DZHK Use and Access Policy, and the Ethics and Data Protection Concept. This framework is characterised by a modular design allowing a high standardisation across all studies. For studies that require even tighter criteria additional quality levels are defined. In addition, the Public Open Data strategy is an important focus of DZHK. The DZHK operates as one legal entity holding all rights of data and biological sample usage, according to the DZHK Use and Access Policy. All DZHK studies collect a basic set of data and biosamples, accompanied by specific clinical and imaging data and biobanking. The DZHK infrastructure was constructed by scientists with the focus on the needs of scientists conducting clinical studies. Through this, the DZHK enables the interdisciplinary and multiple use of data and biological samples by scientists inside and outside the DZHK. So far, 27 DZHK studies recruited well over 11,200 participants suffering from major cardiovascular disorders such as myocardial infarction or heart failure. Currently, data and samples of five DZHK studies of the DZHK Heart Bank can be applied for
Active Galactic Nuclei: Sources for ultra high energy cosmic rays?
The origin of ultra high energy cosmic rays promises to lead us to a deeper
understanding of the structure of matter. This is possible through the study of
particle collisions at center-of-mass energies in interactions far larger than
anything possible with the Large Hadron Collider, albeit at the substantial
cost of no control over the sources and interaction sites. For the extreme
energies we have to identify and understand the sources first, before trying to
use them as physics laboratories. Here we describe the current stage of this
exploration. The most promising contenders as sources are radio galaxies and
gamma ray bursts. The sky distribution of observed events yields a hint
favoring radio galaxies. Key in this quest are the intergalactic and galactic
magnetic fields, whose strength and structure are not yet fully understood.
Current data and statistics do not yet allow a final judgment. We outline how
we may progress in the near future.Comment: proceedings for "Origin, Mass, Composition and Acceleration
Mechanisms of UHECRs (CRIS 2008)" in Malfa (Salina Island - Italy) on
September 15-19, 200
Global Retinoblastoma Presentation and Analysis by National Income Level.
Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs
The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries
DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt
Evaluation of cost-effectiveness in selected high-performance cardiovascular diagnostic and therapeutic procedures
Hintergrund - Erkrankungen des Herz-Kreislaufsystems stellen in Deutschland
eine große Herausforderung dar, sowohl medizinisch als auch ökonomisch. Neben
dem demographischen Wandel wird insbesondere der medizinisch-technische
Fortschritt für einen kontinuierlichen Anstieg der Behandlungskosten
verantwortlich gemacht. Bei begrenzten Ressourcen im Gesundheitssystem werden
Kosteneffektivitätsanalysen zunehmend wichtiger. Das Ziel der vorliegenden
Arbeit war es, ausgewählte diagnostische und therapeutische Prozeduren aus dem
Bereich der kardiovaskulären Hochleistungsmedizin gesundheitsökonomisch zu
evaluieren. Methoden - Die folgenden drei Prozeduren wurden analysiert: 1)
Therapie der Restenose eines Medikamenten-beschichteten Koronar-Stents (DES)
mittels Angioplastie mit einem Medikamenten-beschichteten Ballon (DCB), 2)
Diagnose einer stenosierenden koronaren Herzkrankheit (KHK) mittels kardialer
Stress-Magnetresonanztomographie (MRT) und 3) Therapie der resistenten
Hypertonie durch kathetergestützte renale Sympathikusdenervation (RDN). Die
gesundheitsökonomische Evaluation erfolgte mit Hilfe von Markov-Modellen oder
mittels auf dem Bayes-Theorem basierender Modellierung. Alle Daten und Modell-
Parameter wurden der Literatur entnommen. Die Kostenanalysen wurden aus Sicht
der Kostenträger des deutschen Gesundheitswesens durchgeführt. Als
Effektivitätskriterium dienten gewonnene Lebensjahre (LYs) und/oder
qualitätsadjustierte Lebensjahre (QALYs). Es wurden jeweils umfangreiche
Sensitivitätsanalysen durchgeführt. Ergebnisse - In der ersten
Kosteneffektivitätsanalyse betrugen die Prozedurkosten für die DCB-
Angioplastie 3.488 € sowie 2.782 € für die konventionelle Ballon-Angioplastie
(POBA). Über einen 6-Monatszeitraum zeigte sich die DCB- gegenüber der POBA-
Strategie kostengünstiger (4.028 € versus 4.169 €) und effektiver (0,497
versus 0,489 LYs). Eine erneute DES-Implantation war mit Prozedurkosten von
3.167 € behaftet und war im Vergleich zur DCB-Therapie weniger effektiv (0,494
LYs) und kostenintensiver (4.101 €). In der zweiten Analyse zeigte sich die
kardiale Stress-MRT im Vergleich zur Single-Photonen-Emissions-
Computertomographie (SPECT) als kostengünstiger. Bei einer KHK-Prävalenz von
50% fielen bei der MRT im Vergleich zur SPECT niedrigere Gesamtkosten pro
korrekter KHK-Diagnose (6.120 € versus 7.065 €) und pro hinzugewonnener
Lebenszeit (ΔQALY) an (2.246 € versus 2.931 €). Die dritte
Kosteneffektivitätsanalyse ergab, dass im Vergleich zur bestmöglichen
Pharmakotherapie die RDN in der Altersgruppe der 60-Jährigen mit einen Gewinn
von 0,98 QALYs (Männer) bzw. 0,88 QALYs (Frauen) bei zusätzlichen Kosten von
2.589 € bzw. 2.044 € assoziiert war. Bei einer Zahlungsbereitschaft von 35.000
€/QALY blieb die RDN mit 95%iger Wahrscheinlichkeit bis zu einem Alter von 78
Jahren (Männer) bzw. 76 Jahren (Frauen) kosteneffektiv. Schlussfolgerung - Die
Analysen aus dem Bereich der kardiovaskulären Hochleistungsmedizin konnten
zeigen, dass 1) die DCB-Angioplastie eine überwiegend kostensparende
Therapieoption für die DES-Restenose darstellt, 2) die kardiale Stress-MRT im
Vergleich zur SPECT gesundheitsökonomisch attraktiver ist 3) die RDN eine
kosteneffektive Behandlung der resistenten Hypertonie darstellt. Innovative
medizinische Prozeduren führen nicht pauschal zu Kostensteigerungen, sondern
bedürfen einer differenzierten gesundheitsökonomischen Bewertung.Background - The management of cardiovascular disease poses a significant
challenge for the German health care system, both medically and economically.
In addition to demographic change, technologic innovation is considered to be
a major cause of continuously rising health care costs. In the face of scarce
health care resources, cost-effectiveness analysis is becoming increasingly
important. The aim of the present thesis was a health economic evaluation of
selected diagnostic and therapeutic procedures from the field of
cardiovascular high-performance medicine. Methods - The analysis comprised the
following three procedures: 1) treatment of restenosis of a coronary drug-
eluting stent (DES) with a drug-coated balloon (DCB), 2) stress cardiovascular
magnetic resonance (CMR) imaging for the detection of significant coronary
artery disease (CAD), and 3) treatment of resistant hypertension by catheter-
based renal sympathetic denervation (RDN). Health economic analyses were
performed using Markov models or models based on the equations of Bayes’
theorem. All data and model parameters were derived from the literature. Cost
analyses were conducted from a German health care payer’s perspective. The key
effectiveness criterion was the number of life years (LYs) and/or quality-
adjusted life-years (QALYs) gained. Extensive sensitivity analyses were
performed, respectively. Results - In the first cost-effectiveness analysis,
initial procedure costs were 3,488 € for DCB angioplasty and 2,782 € for plain
old balloon angioplasty (POBA). Over a 6-month horizon, the DCB strategy was
found to be less costly (4,028 € versus 4,169 €) and more effective (0.497
versus 0.489 LYs gained) than the POBA strategy. Repeat stenting with a DES
was associated with procedure costs of 3,167 € and was, in comparison with the
DCB therapy, less effective (0.494 LYs) and more cost-intensive (4,101 €). In
the second cost-effectiveness analysis, CMR was found be less costly when
compared to single photon emission computed tomography (SPECT) imaging. At a
prevalence of CAD of 50%, CMR incurred lower total costs than SPECT per
correct CAD diagnosis (6,120 € versus 7,065 €) and per lifetime (ΔQALY) gained
(2,246 € versus 2,931 €). The third cost-effectiveness analysis showed that,
in comparison to optimal pharmacotherapy, RDN gained 0.98 QALYs in men and
0.88 QALYs in women 60 years of age at additional costs of 2,589 € and 2,044
€, respectively. Given a willingness-to-pay threshold of 35.000 €/QALY, RDN
had a 95% probability to remain cost-effective up to an age of 78 years in men
and 76 years in women. Conclusion - The analyses from the field of
cardiovascular high-performance medicine could show that 1) DCB angioplasty is
a predominantly cost-saving treatment option for DES restenosis, 2) that CMR
is health economically more favorable when compared to SPECT, and 3) that RDN
offers a cost-effective treatment option for resistant hypertension.
Innovative medical procedures do not necessarily increase costs, but rather
require differentiated health economic evaluations
Phänomenologie der Beziehungsgewalt in Hamburg
Ziel der Untersuchung ist die erstmalige Beschreibung des Phänomens Beziehungsgewalt
auf Basis polizeilicher Erkenntnisse
Agil och rekonfigurerbar produktion : projektmetod och utformning av produktionssystem
För att kunna hantera dagens snabba förändringar är agilitet en färdighet svenska tillverkande företag behöver besitta och kontinuerligt utveckla vidare. Kärnpunkten i att vara en agil verksamhet är att snabbt kunna agera på förändringarpå marknaden eller omgivningen med ett fokus på kundens behov som kräver anpassade snarare än standardiserade produkter. Agilitet inbegriper många olika begrepp som idag cirkulerar kring förmågan att snabbt anpassa sig och förändra sin produktion eller sin organisation till förändringar på marknaden. Relaterade begrepp är flexibilitet, rekonfigurerbarhet och resiliens. Rekonfigurerbarhet innebär att göra det möjligt att lägga till, ta bort och / eller ordna om element/beståndsdelar i produktionssystemet på ett snabbt och kostnadseffektivt sätt som kan resultera i en önskad uppsättning alternativa konfigurationer. Denna handbok är framtagen för att ge ett stöd till tillverkande svensk industri vid utveckling av agila och rekonfigurerbara produktionssystem. Detta innefattar både att använda agila projektmetoder och att skapa agila och rekonfigurerbara produktionssystem. Oavsett om företaget står inför en större förändring av befintliga produktionssystem eller ska utforma något alldeles nytt är handboken användbar. Den är ett stöd både för projektgenomförandet och för hur det faktiska produktionssystemet ska utformas utifrån agila principer. Handboken behandlar således både projektmetod (kap 2) och utformning av ett agilt och rekonfigurerbart produktionssystem(kap 3).Nästa generations drivlineproduktio