Housing preferences among students: collective housing versus individual accommodations? A stated preference study in Antwerp (Belgium)

Collective housing or cohousing has gained popularity in the housing market because it promotes social, economic and environmental sustainability, and contributes to a better quality of life. While young professionals are increasingly choosing for peer-shared housing, student expectations are increasing with regard to personal space and comfort. Following the massive expansion of the student population, private sector developers have recently become more involved in the student accommodation market providing high standard expensive single person flats. Responding to a lack of attention to student housing preferences in both student housing and cohousing research, this study aims to discover housing preferences of Belgian students with a focus on the relative importance they attach to private versus shared amenities. We carried out a stated preference experiment among students in higher education in Antwerp. Our results show that the main point of interest for the majority of the students is the type of housing, followed by rent and size. Regarding the type of housing, a studio flat is the most preferred accommodation, while living in a student room in the same house as the landlord the least preferred. Hence, our results show a high preference for private facilities. We conclude that private investors are actually responding to current student preferences. As their high standard student housing projects are easy to construct, maintain and organise, we expect more of them in the near future. However, the willingness to pay of university students is significantly lower than that of university college students who study 1 or 2 years less. Consequently, a demand for a diversified student housing market will presumably persist.     

Support effects in hydrogenation of cinnamaldehyde over carbon nanofiber-supported platinum catalysts: Kinetic modeling

Carbon nanofiber-supported platinum catalysts with a narrow and stable platinum particle size distribution (1-2 nm) were prepared, one with a considerable amount of oxygen support surface groups (PtCNF, 2.8 acidic O atoms/nm²) and one with a much smaller amount (PtCNF973, 0.06 acidic O atoms/nm²). Their catalytic performance was compared in a series of liquid-phase cinnamaldehyde hydrogenation experiments at 383 K using hydrogen pressures of 2.8-6.8 MPa and a cinnamaldehyde concentration in the range 14-. These results showed a different hydrogen dependency of the reaction rate for the two catalysts, demonstrating a change in the adsorption of hydrogen on platinum. Using a single-site model including both Langmuir-Hinshelwood kinetics and mass transfer effects we found that the intrinsic reaction rate increased up to a factor of 120 with the removal of the oxygen-containing surface groups. Also the adsorption constants increased significantly, indicating that adsorption on PtCNF973 is stronger than on PtCNF. These results suggest that hydrogenation is assisted by adsorption of the benzene ring of cinnamaldehyde on the non-polar CNF support surface after removal of the oxygen-containing groups.     

Firm-level knowledge accumulation and regional dynamics

Two literatures have contributed to our insight into the determinantsof economic growth. Regional agglomeration studies emphasizethe favourable impact of geographical proximity on performance.However, the firms that constitute those agglomerations largelyremain black boxes. In contrast, studies about technologicallearning explain economic performance at the firm level withoutsystematically taking account of proximity effects. This paperproposes a possible way of bridging this gap by fusing elementsfrom both partial literatures into an integrated framework.Its value added is illustrated with an empirical example.     

The UI octoson--a new class of ultrasonic echoscope

Glucokinase, phosphoglucomutase and glucose-1-phosphate uridylyltransferase are the three enzymes involved in a microsomic pathway for the synthesis of UDP glucose. Evidence is given, in this paper, for the localization of these three enzymes in a Golgi-rich fraction of rat liver. This fraction is prepared, from smooth microsomes, by the means of a discontinuous four-step sucrose gradient. Three of the lighter fractions (d = 1.08-1.13) are enriched in the Golgi markers (galactosyltransferase, sialytransferase and thiamin pyrophosphatase), especially the one with density 1.13. The three enzymes we are interested in are enriched in the two upper hands (d 1.08-1.11), which display an activity for the biosynthesis of UDP-glucose from glucose equivalent to the one obtained in a crude microsomic preparation, and which are not contaminated by other subcellular components.     

A bias interpretation of facilitation in perceptual identification.

In a typical perceptual identification task, a word is presented for a few milliseconds and masked; then subjects are asked to report the word. It has been found that an earlier presentation of the test word will improve identification of the test word by as much as 30%. In addition, this facilitation has been shown to be preserved under amnesia. In this article we examined a fundamental question: Is the facilitation the result of bias toward the earlier presented item, an improvement in perceptual sensitivity, or both? The experiments presented here use a forced choice procedure to show that prior presentation of an item biases the subject to choose that item but does not improve discriminability. This result is obtained when the distractor items are visually similar to the target items. When distractors are dissimilar, earlier presentation affects neither bias nor discriminability. Two models of word identification are examined in light of the bias effects, and implications for understanding savings in amnesia are also examined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploitation of Chemical Signaling by Parasitoids: Impact on Host Population Dynamics

Chemical information mediates species interactions in a wide range of organisms. Yet, the effect of chemical information on population dynamics is rarely addressed. We designed a spatio-temporal parasitoid—host model to investigate the population dynamics when both the insect host and the parasitic wasp that attacks it can respond to chemical information. The host species, Drosophila melanogaster, uses food odors and aggregation pheromone to find a suitable resource for reproduction. The larval parasitoid, Leptopilina heterotoma, uses these same odors to find its hosts. We show that when parasitoids can respond to food odors, this negatively affects fruit fly population growth. However, extra parasitoid responsiveness to aggregation pheromone does not affect fruit fly population growth. Our results indicate that the use of the aggregation pheromone by D. melanogaster does not lead to an increased risk of parasitism. Moreover, the use of aggregation pheromone by the host enhances its population growth and enables it to persist at higher parasitoid densities.