Stadtregionen im Spannungsfeld zwischen Wohnungsfrage und Flächensparen: Trends, Strategien und Lösungsansätze in Kernstädten und ihrem Umland

Wachsende Stadtregionen befinden sich in einem Spannungsfeld zwischen hohen Boden- und Wohnungspreisen und nationalen Flächensparzielen. Die Mobilisierung von Bauland zur Schaffung von Wohnraum und die Reduzierung der Flächenneuinanspruchnahme stellen einen Zielkonflikt dar, der nur durch einen integrierten Blick auf die Instrumente zur Adressierung beider Herausforderungen aufgelöst werden kann. Um dieses Spannungsfeld analytisch zu betrachten, werden mithilfe eines regionalen Wirkungsmodells die komplexen Wechselwirkungen zwischen Wohnungsmärkten und der Flächenneuinanspruchnahme für Wohnen in Kernstädten und ihrem Umland abgebildet und als theoretischer Rahmen genutzt. Trends der Siedlungsentwicklung sowie kommunale Lösungsstrategien in deutschen Stadtregionen werden mit einem Mixed-Methods-Ansatz untersucht. Die Ergebnisse zeigen eine steigende Flächeneffizienz in Kernstädten und dem gut erreichbaren und verdichteten Umland bei gleichzeitig hohen, preisbedingten Wanderungsgewinnen im weniger verdichteten Umland, wo nach wie vor Einfamilienhausbautätigkeit dominiert. Es wird deutlich, dass die Flächenfrage im Umland nicht unabhängig von der Wohnungsfrage in den Kernstädten betrachtet werden kann. Nur wenn in den Kernstädten bezahlbarer und qualitätsvoller Wohnraum insbesondere für Familien geschaffen wird, kann die regionale Flächenneuinanspruchnahme minimiert werden. Hierfür ist insgesamt ein konsequenterer Einsatz bestehender boden- und flächenpolitischer Instrumente in Kombination mit einem regionalen Commitment zu höheren Dichten vor allem im Umland notwendig.Growing city regions are in between the poles of high land and housing prices and national land-saving targets. The mobilization of building land to create living space and the reduction of new land take represent a conflict of goals that can only be resolved by taking an integrated look at the instruments for meeting both challenges. In order to address this conflict analytically, a regional causal loop diagram is used to map the complex mechanisms of action between housing markets and new land use for housing in core cities and their hinterland and to use it as a theoretical framework. Using a mixed-methods approach, trends in residential development as well as municipal solution strategies in German city regions are investigated. The results show increasing land use efficiency in core cities and the dense hinterland, with simultaneous high, price-induced migration gains in the less dense hinterland, where single-family housing still dominates. It becomes evident that the questions about land saving in the hinterland and housing in core cities have to be considered mutually. The regional land take can only be minimized if affordable and attractive housing is provided in the core cities, especially for families. For this, a more consistent use of existing land policy instruments in combination with a regional commitment to higher densities, especially in the hinterland, is necessary

Motion estimation and correction for simultaneous PET/MR using SIRF and CIL

SIRF is a powerful PET/MR image reconstruction research tool for processing data and developing new algorithms. In this research, new developments to SIRF are presented, with focus on motion estimation and correction. SIRF's recent inclusion of the adjoint of the resampling operator allows gradient propagation through resampling, enabling the MCIR technique. Another enhancement enabled registering and resampling of complex images, suitable for MRI. Furthermore, SIRF's integration with the optimization library CIL enables the use of novel algorithms. Finally, SPM is now supported, in addition to NiftyReg, for registration. Results of MR and PET MCIR reconstructions are presented, using FISTA and PDHG, respectively. These demonstrate the advantages of incorporating motion correction and variational and structural priors. This article is part of the theme issue 'Synergistic tomographic image reconstruction: part 2'

SIRF: Synergistic Image Reconstruction Framework

The combination of positron emission tomography (PET) with magnetic resonance (MR) imaging opens the way to more accurate diagnosis and improved patient management. At present, the data acquired by PET-MR scanners are essentially processed separately, but the opportunity to improve accuracy of the tomographic reconstruction via synergy of the two imaging techniques is an active area of research. In this paper, we present Release 2.1.0 of the CCP-PETMR Synergistic Image Reconstruction Framework (SIRF) software suite, providing an open-source software platform for efficient implementation and validation of novel reconstruction algorithms. SIRF provides user-friendly Python and MATLAB interfaces built on top of C++ libraries. SIRF uses advanced PET and MR reconstruction software packages and tools. Currently, for PET this is Software for Tomographic Image Reconstruction (STIR); for MR, Gadgetron and ISMRMRD; and for image registration tools, NiftyReg. The software aims to be capable of reconstructing images from acquired scanner data, whilst being simple enough to be used for educational purposes

SIRF: Synergistic Image Reconstruction Framework

The combination of positron emission tomography (PET) with magnetic resonance (MR) imaging opens the way to more accurate diagnosis and improved patient management. At present, the data acquired by PET-MR scanners are essentially processed separately, but the opportunity to improve accuracy of the tomographic reconstruction via synergy of the two imaging techniques is an active area of research. In this paper, we present Release 2.1.0 of the CCP-PETMR Synergistic Image Reconstruction Framework (SIRF) software suite, providing an open-source software platform for efficient implementation and validation of novel reconstruction algorithms. SIRF provides user-friendly Python and MATLAB interfaces built on top of C++ libraries. SIRF uses advanced PET and MR reconstruction software packages and tools. Currently, for PET this is Software for Tomographic Image Reconstruction (STIR); for MR, Gadgetron and ISMRMRD; and for image registration tools, NiftyReg. The software aims to be capable of reconstructing images from acquired scanner data, whilst being simple enough to be used for educational purposes. The most recent version of the software can be downloaded from http://www.ccppetmr.ac.uk/downloads and https://github.com/CCPPETMR/. Program summary: Program Title: Synergistic Image Reconstruction Framework (SIRF) Program Files DOI: http://dx.doi.org/10.17632/s45f5jh55j.1 Licensing provisions: GPLv3 and Apache-2.0 Programming languages: C++, C, Python, MATLAB Nature of problem: In current practice, data acquired by PET-MR scanners are processed separately. Methods for improving the accuracy of the tomographic reconstruction using the synergy of the two imaging techniques are actively being investigated by the PET-MR research and development community, however, practical application is heavily reliant on software. Open-source software available to the PET-MR community – such as the PET package (STIR) (Thielemans et al., 2012) and the MR package Gadgetron (Hansen and Sørensen, 2013) – provide a basis for new synergistic PET-MR software. However, these two software packages are independent and have very different software architectures. They are mostly written in C++ but many researchers in the PET-MR community are more familiar with script-style languages, such as Python and MATLAB, which enable rapid prototyping of novel reconstruction algorithms. In the current situation it is difficult for researchers to exploit any synergy between PET and MR data. Furthermore, techniques from one field cannot easily be applied in the other. Solution method: In SIRF, the bulk of computation is performed by available advanced open-source reconstruction and registration software (currently STIR, Gadgetron and NiftyReg) that can use multithreading and GPUs. The SIRF C++ code provides a thin layer on top of these existing libraries. The SIRF layer has unified data-containers and access mechanisms. This C++ layer provides the basis for a simple and intuitive Python and MATLAB interface, enabling users to quickly develop and test their reconstruction algorithms using these scripting languages only. At the same time, advanced users proficient in C++ can directly utilise wider SIRF functionality via the SIRF C++ libraries that we provide

Screening for Mutations Related to Atovaquone/ Proguanil Resistance in Treatment Failures and Other Imported Isolates of Plasmodium falciparum in Europe

Background. Two single-point mutations of the Plasmodium falciparum cytochrome b gene (Tyr268Asn and Tyr268Ser) were recently reported in cases of atovaquone/proguanil (Malarone) treatment failure. However, little is known about the prevalence of codon-268 mutations and their quantitative association with treatment failure. Methods. We set out to assess the prevalence of codon-268 mutations in P. falciparum isolates imported into Europe and to quantify their association with atovaquone/proguanil treatment failure. Isolates of P. falciparum collected by the European Network on Imported Infectious Disease Surveillance between April 2000 and August 2003 were analyzed for codon-268 mutations, by use of polymerase chain reaction-restriction fragment-length polymorphism. Results. We successfully screened 504 samples for the presence of either Tyr268Ser or Tyr268Asn. One case of Ser268 and no cases of Asn268 were detected. Therefore, we can be 95% confident that the prevalence of Ser268 in the European patient pool does not exceed 0.96% and that Asn268 is less frequent than 0.77%. In 58 patients treated with atovaquone/proguanil, Tyr268Ser was present in 1 of 5 patients with treatment failure but in 0 of 53 successfully treated patients. Conclusions. Tyr268Ser seems to be a sufficient, but not a necessary, cause for atovaquone/proguanil treatment failure. The prevalence of both codon-268 mutations is currently unlikely to be >1% in the European patient poo

What (If Anything) Do Satisfaction Scores Tell Us About the Intertemporal Change in Living Conditions?

This paper looks at the information content of satisfaction scores. It is argued that the information content depends on the extent to which people adapt to living conditions in general. Using data from the German Socio-Economic Panel Study (SOEP), the estimation of a dynamic panel data model provides evidence that adaptation takes place within a relatively short window of time: changes in living conditions are, for the most part, absorbed by an adjustment of the adaptation level within one year. This leads to the conclusion that the information content of satisfaction scores accentuates recent changes in living conditions. Remote changes are notcaptured by the according survey questions, even if these changes have long-term impact on living conditions. The usefulness of satisfaction scores as an indicator of people's living conditions is discussed