Spatial analysis of residential development processes:uncovering the Dutch densification potential

Urban areas are rapidly transforming. This is particularly true in the Netherlands where residential development is continuing to claim agricultural land alongside with transforming vacant industrial buildings or filling under-used sites. How to steer future urban development is the topic of heated debates and especially the potential of urban transformations to accommodate the projected growth in housing stock is questioned. We study the feasibility of further intensification with a spatial analysis approach that distinguishes different residential development processes and quantifies their relative importance. Using highly detailed cadastral data related to location, age and function of all individual buildings in the country, we differentiate between processes such as: densification of residential neighbourhoods, transformation of brownfields and greyfields and green field redevelopment. Our results indicate that just over half of the total net increase of around 1 million residences in the past 17 years took place within the existing urban fabric. Only a small proportion of the total increase (5.5%) was placed on former green areas within cities, whereas densification of existing residential areas and transformation accommodated 25% and 21% of the increase respectively. Using binomial logistic regression techniques, we assess the importance of a range of different drivers for this process. The results suggest that there is still substantial scope for further intensification in the coming decades when another million or so new residences have to be constructed

Are current cities dense enough?:a case study for the Netherlands

One of the main predictions of urban economic theory is that the density of land use reacts to the price of land. For many activities, substitution between land and built-up structure is possible when land is scarce, often by constructing more square meters of floor space on a given amount of land. In recent decades, interest in living and working in (big) cities has increased markedly and urban land prices have increased substantially. Since it appears unlikely that the cost of construction of square meters of floor space has increased much or more than land prices, one expects that optimal land use is now denser than it was in the past. This seems to be confirmed by recent observations of densification in Dutch urban areas. Density of urban areas has implications for traffic, energy use, the total size of the urban area and agglomeration benefits in consumption and production. The sluggish response to higher land prices that is associated with durable real estate and significant adjustment costs probably implies that actual cities are less dense than would be optimal. For this research a spatial model is developed that offers the possibility to systematically investigate the issue of densification. It compares the density of current and alternative uses in the Netherlands. Alternative uses are calculated using for this research constructed hedonic price indices (based on roughly 70% of all house transactions in the Netherlands), construction costs and demolition costs. Analysis of past changes in land use, using information of the relevant prices and construction costs offers the possibility to consider the conditions under which a switch to higher density takes place as well as the ‘jump’ in density that may occur. This offers insight into the speed with which the adjustment to higher density takes place. Moreover, the results provide an important ingredient for a general equilibrium analysis of the way the city would look like if adjustment would be complete. In this analysis it is taken into account that in the rebuilt city more households can live and more workers can be employed in a square kilometre, which implies that with the same population and employment size the city can be smaller. This implies that prices of existing real estate at the current edge of the city will adjust in the absence of population growth, thereby counteracting further densification

Analysing the potential for further urban densification: a case study for the Netherlands

Urban areas in the Netherlands are rapidly transforming. Many new houses have been built to replace e.g. vacant industrial buildings or fill under-used sites, but it is unclear whether such transformations can accommodate the projected growth in housing stock. This study analyses the spatial and economic feasibility of further intensification. It focusses on quantifying the costs and benefits of two types of densification: changing the main function of current urban areas (e.g. from industrial to residential), or densifying these areas (i.e. adding extra housing units to existing residential areas). In order to quantify the different components of these transformation costs, a literature study and interviews with sector experts were conducted. These main factors influencing the local costs and benefits for densification include: actual land-use, building-type, building age, soil contamination, accessibility, and others. In cooperation with the municipality of The Hague, a case study was set up to analyse a selection of potential transformation sites in the city. This case study aided in revealing the different costs and benefits of transformation projects. Using the insights gained in the literature review and case study analysis and applying a spatially-explicit modelling approach (Land Use Scanner), we simulated potential transformation under different socio-economic scenarios. In this approach the potential for transformation was calculated based on current land-use, zoning regulations, building characteristics, transformation costs and other location-specific characteristics related to for example local accessibility. These suitability scores were used in combination with the regional projected housing demand to find the most likely areas for urban densification/transformation. Furthermore, this tool is used to evaluate the implications of relevant alternative policy measures

Aircraft noise control policy and mental health: a natural experiment based on the Longitudinal Aging Study Amsterdam (LASA)

Background This study examines the impact of environmental noise policy on depressive symptoms by exploiting the national experiment afforded by the New Deal aircraft noise control policy introduced in Schiphol (Amsterdam) in 2008. Methods Data came from older adults (ages 57-102) participating in three waves (2005/2006, 2008/2009 and 2011/2012) of the Longitudinal Aging Study Amsterdam (LASA) (N=1746). Aircraft noise data from the Netherlands Environmental Assessment Agency were linked to LASA cohort addresses using the GeoDMS software. The Centre for Epidemiologic Studies-Depression (CES-D) scale was used to measure depressive symptoms. Using a difference-in-dfferences (DiD) approach, we compared changes in CES-D levels of depressive symptoms before and after the policy between people living close (≤15 km) and those living far away (>15 km) from Schiphol airport. Results There were few changes in noise levels after the introduction of the policy. Estimates suggested that the policy did not lead to a reduction in noise levels in the treatment areas relative to the control areas (DiD estimate=0.916 dB(A), SE=0.345), and it had no significant impact on levels of depressive symptoms (DiD estimate=0.044, SE=0.704). Results were robust to applying different distance thresholds. Conclusion The New Deal aircraft noise control policy introduced in Amsterdam was not effective in reducing aircraft noise levels and had no impact on depressive symptoms in older people. Our results raise questions about the effectiveness of the current noise control policy to improve the well-being of residents living near the airport

Adaptation of Akkermansia muciniphila to the Oxic-Anoxic Interface of the Mucus Layer

Akkermansia muciniphila colonizes the mucus layer of the gastrointestinal tract, where the organism can be exposed to the oxygen that diffuses from epithelial cells. To understand how A. muciniphila is able to survive and grow at this oxic-anoxic interface, its oxygen tolerance and response and reduction capacities were studied. A. muciniphila was found to be oxygen tolerant. On top of this, under aerated conditions, A. muciniphila showed significant oxygen reduction capacities and its growth rate and yield were increased compared to those seen under strict anaerobic conditions. Transcriptome analysis revealed an initial oxygen stress response upon exposure to oxygen. Thereafter, genes related to respiration were expressed, including those coding for the cytochrome bd complex, which can function as a terminal oxidase. The functionality of A. muciniphila cytochrome bd genes was proven by successfully complementing cytochrome-deficient Escherichia coli strain ECOM4. We conclude that A. muciniphila can use oxygen when it is present at nanomolar concentrations. IMPORTANCE This article explains how Akkermansia muciniphila, previously described as a strictly anaerobic bacterium, is able to tolerate and even benefit from low levels of oxygen. Interestingly, we measured growth enhancement of A. muciniphila and changes in metabolism as a result of the oxygen exposure. In this article, we discuss similarities and differences of this oxygen-responsive mechanism with respect to those of other intestinal anaerobic isolates. Taken together, we think that these are valuable data that indicate how anaerobic intestinal colonizing bacteria can exploit low levels of oxygen present in the mucus layer and that our results have direct relevance for applicability, as addition of low oxygen concentrations could benefit the in vitro growth of certain anaerobic organisms.Peer reviewe

Secondary analysis of tuberculosis stigma data from a cluster randomised trial in Zambia and South Africa (ZAMSTAR).

SETTING: Zambian and South African TB and HIV Reduction (ZAMSTAR) cluster-randomised trial (CRT) communities, 2006-2009. OBJECTIVES: To develop TB stigma items, and evaluate changes in them in response to a household intervention aimed at reducing TB transmission and prevalence but not tailored to reduce stigma. DESIGN: TB stigma was measured at baseline and 18 months later among 1826 recently diagnosed TB patients and 1235 adult members of their households across 24 communities; 12 of 24 communities were randomised to receive the household intervention. We estimated the impact of the household intervention on TB stigma using standard CRT analytical methods. RESULTS: Among household members, prevalence of blame and belief in transmission myths fell in both study arms over time: adjusted prevalence ratios (aPRs) comparing the household intervention with the non-household intervention arm were respectively 0.61 (95%CI 0.26-1.44) and 0.77 (95%CI 0.48-1.25) at 18-month follow-up. Among TB patients, at baseline a low percentage experienced social exclusion and poor treatment by health staff and a relatively high percentage reported 'being made fun of', with little change over time. Disclosure of TB status increased over time in both study arms. Internalised stigma was less prevalent in the household arm at both baseline and follow-up, with an aPR of 0.85 (95%CI 0.41-1.76). Variability in stigma levels between countries and across communities was large. CONCLUSION: Robust TB stigma items were developed. TB stigma was not significantly reduced by the household intervention, although confidence intervals for estimated intervention effects were wide. We suggest that stigma-specific interventions are required to effectively address TB stigma

Bicistronic Design-Based Continuous and High-Level Membrane Protein Production in Escherichia coil

Escherichia coli has been widely used as a platform microorganism for both membrane protein production and cell factory engineering. The current methods to produce membrane proteins in this organism require the induction of target gene expression and often result in unstable, low yields. Here, we present a method combining a constitutive promoter with a library of bicistronic design (BCD) elements, which enables inducer-free, tuned translation initiation for optimal protein production. Our system mediates stable, constitutive production of bacterial membrane proteins at yields that outperform those obtained with E. coli Lemo21(DE3), the current gold standard for bacterial membrane protein production. We envisage that the continuous, fine-tunable, and high-level production of membrane proteins by our method will greatly facilitate their study and their utilization in engineering cell factories.Peer reviewe

A genotype-guided strategy for oral P2Y₁₂ Inhibitors in primary PCI

BACKGROUND: It is unknown whether patients undergoing primary percutaneous coronary intervention (PCI) benefit from genotype-guided selection of oral P2Y12 inhibitors. METHODS: We conducted a randomized, open-label, assessor-blinded trial in which patients undergoing primary PCI with stent implantation were assigned in a 1:1 ratio to receive either a P2Y12 inhibitor on the basis of early CYP2C19 genetic testing (genotype-guided group) or standard treatment with either ticagrelor or prasugrel (standard-treatment group) for 12 months. In the genotype-guided group, carriers of CYP2C19*2 or CYP2C19*3 loss-of-function alleles received ticagrelor or prasugrel, and noncarriers received clopidogrel. The two primary outcomes were net adverse clinical events - defined as death from any cause, myocardial infarction, definite stent thrombosis, stroke, or major bleeding defined according to Platelet Inhibition and Patient Outcomes (PLATO) criteria - at 12 months (primary combined outcome; tested for noninferiority, with a noninferiority margin of 2 percentage points for the absolute difference) and PLATO major or minor bleeding at 12 months (primary bleeding outcome). RESULTS: For the primary analysis, 2488 patients were included: 1242 in the genotype-guided group and 1246 in the standard-treatment group. The primary combined outcome occurred in 63 patients (5.1%) in the genotype-guided group and in 73 patients (5.9%) in the standard-treatment group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.0 to 0.7; P<0.001 for noninferiority). The primary bleeding outcome occurred in 122 patients (9.8%) in the genotype-guided group and in 156 patients (12.5%) in the standard-treatment group (hazard ratio, 0.78; 95% CI, 0.61 to 0.98; P = 0.04). CONCLUSIONS: In patients undergoing primary PCI, a CYP2C19 genotype-guided strategy for selection of oral P2Y12 inhibitor therapy was noninferior to standard treatment with ticagrelor or prasugrel at 12 months with respect to thrombotic events and resulted in a lower incidence of bleeding. (Funded by the Netherlands Organization for Health Research and Development; POPular Genetics ClinicalTrials.gov number, NCT01761786; Netherlands Trial Register number, NL2872.)