2,840 research outputs found
Dynamic Models of Wasserstein-1-Type Unbalanced Transport
We consider a class of convex optimization problems modelling temporal mass
transport and mass change between two given mass distributions (the so-called
dynamic formulation of unbalanced transport), where we focus on those models
for which transport costs are proportional to transport distance. For those
models we derive an equivalent, computationally more efficient static
formulation, we perform a detailed analysis of the model optimizers and the
associated optimal mass change and transport, and we examine which static
models are generated by a corresponding equivalent dynamic one. Alongside we
discuss thoroughly how the employed model formulations relate to other
formulations found in the literature.Comment: to appear in ESAIM: Control, Optimisation and Calculus of Variation
1995 Annual Report Palmyra Maine
Original scanned reports courtesy of Palmyra Historical Societ
The Impact of the Bologna Reform on Student Outcomes
How did the introduction of the Bachelor-degree system affect students in Ger-
many? Combining rich data on university students with administrative data
on universities' study programs, we exploit variation in the timing of Bachelor-
degree implementation across departments. To account for endogeneity in stu-
dents' enrollment decisions, we apply an instrumental-variable approach based
on the distance differential between an individual's nearest universities with a
Bachelor's and a traditional degree program. Overall, we do not find reform ef-
fects on students' mobility, drop out, and internship participation, although there
is indication that the reform reduced drop out for females and for high-achieving
students and increased study satisfaction
A Bayesian model for dynamic mass reconstruction from PET listmode data
Positron emission tomography (PET) is a classical imaging technique to
reconstruct the mass distribution of a radioactive material. If the mass
distribution is static, this essentially leads to inversion of the X-ray
transform. However, if the mass distribution changes temporally, the
measurement signals received over time (the so-called listmode data) belong to
different spatial configurations. We suggest and analyse a Bayesian approach to
solve this dynamic inverse problem that is based on optimal transport
regularization of the temporally changing mass distribution. Our focus lies on
a rigorous derivation of the Bayesian model and the analysis of its properties,
treating both the continuous as well as the discrete (finitely many detectors
and time binning) setting
Einfluss eines Implantierbaren Cardioverter Defibrillators ohne (ICD) oder mit kardialer Resynchronisationstherapie (CRT-D) auf Herzangst, allgemeine Angst, Depression und Lebensqualität : Ergebnisse der Anxiety in Patients with Chronic-Heart-Failure-Study (Anxiety-CHF)
Hintergrund: Psychische Komorbiditäten werden bei Patienten mit Indikation für einen Implantierbaren Cardioverter Defibrillator ohne- (ICD) oder mit biventrikulärer Schrittmacherfunktion (CRT-D) häufig beobachtet und können Lebensqualität und Prognose beeinträchtigen. Der Einfluss einer ICD- oder CRT-D-Implantation auf die psychologische Komorbidität ist noch nicht hinreichend untersucht. Ziel der prospektiven Anxiety in Patients with Chronic Heart Failure Studie (Anxiety-CHF) ist die Untersuchung des Effekts einer ICD- oder CRT-D-Implantation auf Herzangst, allgemeine Angst, Depression und Lebensqualität.
Methoden: Patienten (n= 132) (71 % männlich; mittleres Alter 60,9 ± Jahre; linksventrikuläre Ejektionsfraktion 30,6 ± 8,7) mit Indikation zur ICD- (n= 88) oder CRT-D-Implantation (n= 44) (91,7 % Primärprophylaxe) wurden vor- und 5- (5M), 12- (12M) und 24 Monate (24M) nach Implantation untersucht. Zur Erhebung psychischer Parameter wurde der Herzangstfragebogen (HAF) zur Erfassung von Herzangst, die Hospital Anxiety and Depression Scale (HADS) zur Erfassung von Symptomen allgemeiner Angst und Depression sowie der Minnesota Living with Heart Failure Questionnaire (MLHFQ) zur Bestimmung der Lebensqualität verwendet. Zusätzlich wurden ICD-spezifische Parameter wie die Anzahl und die Auslöser von Schockabgaben und Antitachykardem Pacing (ATP) sowie die Zahl an Hospitalisierungen erfasst.
Ergebnisse: Vor ICD-/CRT-D-Implantation zeigten 43,5 % der Patienten klinisch signifikante Herzangst, während die Lebensqualität bei 68 % eingeschränkt war. Klinisch signifikante Werte allgemeiner Angst und Depression wurden bei 13,7 %, respektive 11,4 % der Patienten nachgewiesen. Erhöhte Werte wurde bei Frauen (p= 0,05 für allgemeine Angst, p= 0,018 für LQ und p= 0,021 für die MLHFQ-Subskala „Körperliche Leistungsfähigkeit“) und Patienten unter 63 Jahren (p= 0,009 für allgemeine Angst und p= 0,006 für die MLHFQ-Subskala „Emotionales Befinden“) gemessen. Nach Device-Implantation zeigte sich bei Patienten mit CRT-D eine über 24 Monate persistierende Verbesserung der Herzangst (p< 0,001), einschließlich der Herzangst-Subskalen Furcht (p< 0,001) und Aufmerksamkeit (p< 0,001) und eine Verbesserung des emotionalen Befindens (p= 0,005). ICD-Patienten profitierten im Hinblick auf die Herzangst-Subskala Aufmerksamkeit (p= 0,004), während die Ausprägung der übrigen Parameter unverändert blieb. In beiden Gruppen blieben das herzangstspezifische Vermeidungsverhalten und die Depressionssymptomatik unverändert hoch. Bei Patienten, die ein ATP (n= 20; 15,4 %) und oder eine Schockabgabe (n= 7; 5,4 %) erlebten, kam es nach 24 Monaten zu einer Steigerung der Herzangstwerte (p= 0,009) und des herzangstspezifischen Vermeidungsverhaltens (p= 0,004).
Schlussfolgerungen: Eine CRT-D-, nicht aber eine alleinige ICD-Implantation ist mit einer Verbesserung der LQ und einer Abnahme von Herzangst und allgemeiner Angst assoziiert. Insbesondere Frauen, Device-Empfänger unter 63 Jahren und Patienten nach Schock/ATP-Abgabe sind von Herzangst, allgemeiner Angst oder einer Einschränkung der LQ betroffen. Besonders bei diesen Patienten sollte auf psychologische Komorbiditäten, einschließlich Herzangst, geachtet werden und gegebenenfalls eine psychotherapeutische Mitbetreuung erfolgen
Secondary stroke prevention: patent foramen ovale, aortic plaque, and carotid stenosis
Stroke is the most debilitating cardiovascular event. It has a variety of causes that may be present simultaneously. In young or otherwise healthy people, the search for a patent foramen ovale (PFO) has become standard. In stroke of the elderly, atherosclerosis and atrial fibrillation are in the foreground but the PFO should not be ignored. The risk of a PFO-related stroke over time is controversial and so is its prevention by device closure. The association of proximal aortic plaques in arteries subtending the brain and stroke is considered strong, ignoring that it is as putative as that of the PFO. Statins can prevent progression of such plaques. Antiplatelet agents in asymptomatic and surgical endarterectomy in symptomatic patients or highly ulcerated lesions are the treatment of choice. Stenting with protection devices was shown competitive in selected patient
Expert exploranation for communicating scientific methods - A case study in conflict research
Science communication aims at making key research insights accessible to the broad public. If explanatory and exploratory visualization techniques are combined to do so, the approach is also referred to as exploranation. In this context, the audience is usually not required to have domain expertise. However, we show that exploranation can not only support the communication between researchers and a broad audience, but also between researchers directly.
With the goal of communicating an existing method for conducting causal inference on spatio-temporal conflict event data, we investigated how to perform exploranation for experts, i.e., expert exploranation. Based on application scenarios of the inference method, we developed three versions of an interactive visual story to explain the method to conflict researchers. We abstracted the corresponding design process and evaluated the stories both with experts who were unfamiliar with the explained method and experts who were already familiar with it.
The positive and extensive feedback from the evaluation shows that expert exploranation is a promising direction for visual storytelling, as it can help to improve scientific outreach, methodological understanding, and accessibility for researchers new to a field
How Is CYP17A1 Activity Altered in Autism? A Pilot Study to Identify Potential Pharmacological Targets.
Background: Increasing evidence exists that higher levels of androgens can be found in individuals with autism. Evidence yields to a susceptible role of Cytochrome P450 17A1 (CYP17A1) with its catalyzation of the two distinct types of substrate oxidation by a hydroxylase activity (17-alpha hydroxylase) and C17/20 lyase activity. However, to what extent steps are altered in affected children with autism versus healthy controls remains to be elucidated. Methods: Urine samples from 48 boys with autism (BMI 19.1 ± 0.6 kg/m2, age 14.2 ± 0.5 years) and a matched cohort of 48 healthy boys (BMI 18.6 ± 0.3 kg/m2, 14.3 ± 0.5 years) as well as 16 girls with autism (BMI 17.5 ± 0.7 kg/m2, age 13.8 ± 1.0 years) and a matched cohort of 16 healthy girls (BMI 17.2 ± 0.8 kg/m2, age 13.2 ± 0.8 years) were analyzed for steroid hormone metabolites by gas chromatography-mass spectrometry. Results: The activity of 17-alpha Hydroxylase increased by almost 50%, whereas activity of 17/20 Lyase activity increased by around 150% in affected children with autism. Furthermore, the concentration of Cortisol was higher as compared to the average increase of the three metabolites TH-Corticosterone, 5α-TH-Corticosterone and TH-11β-DH-Corticosterone, indicating, in addition, a stimulation by the CRH-ACTH system despite a higher enzymatic activity. Discussion: As it was shown that oxidative stress increases the 17/20-lyase activity via p38α, a link between higher steroid hormone levels and oxidative stress can be established. However, as glucocorticoid as well as androgen metabolites showed higher values in subjects affected with autism as compared to healthy controls, the data indicate, despite higher CYP17A1 activity, the presence of increased substrate availability in line with the Cholesterol theory of autism
- …