Expression of Interest ICES/KIS-3 : Thema 4: Hoogwaardig Ruimtegebruik Speerpunt 6

Hoofddoel van dit speerpunt is om zowel de Nederlandse overheid als het bedrijfsleven uit te rusten met een operationele kennisinfrastructuur die toegesneden is op de relatie tussen (antropogene en natuurlijke) klimaatverandering en meervoudig ruimtegebrui

Non-Medical Use of Cognitive Enhancing Prescription Medications Among Occupational Therapy and Speech Language Pathology Health Care Students: A Pilot Study

Purpose: This research was designed to serve as a pilot study to generate baseline data on non-medical use of prescription drugs (NMUPD) for cognitive/academic enhancement purposes among students representing two healthcare professions, Occupational Therapy (OT) and Speech Language Pathology (SLP) and to assess students’ opinions regarding whether use of these medications constitutes academic “cheating.” Introduction: NMUPD, such as Adderall ® or Ritalin ®, to reduce fatigue, improve memory, and increase concentration to ultimately improve grades has increased among college students in recent years, with estimated use put as high as 35% on some campuses. These drugs appear to be readily available to those not prescribed them, with primary sources including family, friends, and classmates. Aside from health concerns stemming from ingesting non-prescribed medications is the ethical concern whether use of such cognitive enhancers is “cheating.” Methods: Following IRB approval, 150 OT and 150 SLP students, randomly selected from membership in their respective national associations, were mailed survey packets containing a cover letter, questionnaire, and return envelope. Results: A total of 51 completed surveys, including 25 OT and 26 SLP students, were returned and included in analyses. Of these, five (9.8%) reported using cognitive enhancing prescription medications. Four of these reported having a legal prescription, including one who admitted faking symptoms of ADHD to access the prescription. The fifth student had no prescription. Motives included recreational enjoyment, to improve attention/concentration, reduce hyperactivity/impulsivity, and to obtain higher grades. Four out of ten students indicated abuse of prescription medications was a problem at their institutions, with three out of ten believing it was easy to obtain such drugs. Students were visibly divided as to whether use of these medications was academic cheating. Conclusions: The percent of these healthcare profession students reporting to have used non-prescribed medications for academic enhancement purposes mirrors that of studies on the general college student population and reflects the division as to whether use constitutes cheating. As the survey is a self-report, the numbers using the prescription medications may be higher. Results indicate future research on NMUPD among healthcare students is warranted, along with a need to educate students on the risks of use of these medications for non-prescribed purposes

Non-Medical Use of Cognitive Enhancing Prescription Medications among Occupational Therapy and Speech Language Pathology Health Care Students: A Pilot Study

Purpose: This research was designed to serve as a pilot study to generate baseline data on non-medical use of prescription drugs (NMUPD) for cognitive/academic enhancement purposes among students representing two healthcare professions, Occupational Therapy (OT) and Speech Language Pathology (SLP) and to assess students’ opinions regarding whether use of these medications constitutes academic “cheating.” Introduction: NMUPD, such as Adderall ® or Ritalin ®, to reduce fatigue, improve memory, and increase concentration to ultimately improve grades has increased among college students in recent years, with estimated use put as high as 35% on some campuses. These drugs appear to be readily available to those not prescribed them, with primary sources including family, friends, and classmates. Aside from health concerns stemming from ingesting nonprescribed medications is the ethical concern whether use of such cognitive enhancers is “cheating.” Methods: Following IRB approval, 150 OT and 150 SLP students, randomly selected from membership in their respective national associations, were mailed survey packets containing a cover letter, questionnaire, and return envelope. Results: A total of 51 completed surveys, including 25 OT and 26 SLP students, were returned and included in analyses. Of these, five (9.8%) reported using cognitive enhancing prescription medications. Four of these reported having a legal prescription, including one who admitted faking symptoms of ADHD to access the prescription. The fifth student had no prescription. Motives included recreational enjoyment, to improve attention/concentration, reduce hyperactivity/impulsivity, and to obtain higher grades. Four out of ten students indicated abuse of prescription medications was a problem at their institutions, with three out of ten believing it was easy to obtain such drugs. Students were visibly divided as to whether use of these medications was academic cheating. Conclusions: The percent of these healthcare profession students reporting to have used non-prescribed medications for academic enhancement purposes mirrors that of studies on the general college student population and reflects the division as to whether use constitutes cheating. As the survey is a self-report, the numbers using the prescription medications may be higher. Results indicate future research on NMUPD among healthcare students is warranted, along with a need to educate students on the risks of use of these medications for non-prescribed purposes

Statistical properties of stock order books: empirical results and models

We investigate several statistical properties of the order book of three liquid stocks of the Paris Bourse. The results are to a large degree independent of the stock studied. The most interesting features concern (i) the statistics of incoming limit order prices, which follows a power-law around the current price with a diverging mean; and (ii) the humped shape of the average order book, which can be quantitatively reproduced using a `zero intelligence' numerical model, and qualitatively predicted using a simple approximation.Comment: Revised version, 10 pages, 4 .eps figures. to appear in Quantitative Financ

Interaction of molecular motors can enhance their efficiency

Particles moving in oscillating potential with broken mirror symmetry are considered. We calculate their energetic efficiency, when acting as molecular motors carrying a load against external force. It is shown that interaction between particles enhances the efficiency in wide range of parameters. Possible consequences for artificial molecular motors are discussed.Comment: 6 pages, 8 figure

Extremal dynamics model on evolving networks

We investigate an extremal dynamics model of evolution with a variable number of units. Due to addition and removal of the units, the topology of the network evolves and the network splits into several clusters. The activity is mostly concentrated in the largest cluster. The time dependence of the number of units exhibits intermittent structure. The self-organized criticality is manifested by a power-law distribution of forward avalanches, but two regimes with distinct exponents tau = 1.98 +- 0.04 and tau^prime = 1.65 +- 0.05 are found. The distribution of extinction sizes obeys a power law with exponent 2.32 +- 0.05.Comment: 4 pages, 5 figure

Criticality and finite size effects in a simple realistic model of stock market

We discuss a simple model based on the Minority Game which reproduces the main stylized facts of anomalous fluctuations in finance. We present the analytic solution of the model in the thermodynamic limit and show that stylized facts arise only close to a line of critical points with non-trivial properties. By a simple argument, we show that, in Minority Games, the emergence of critical fluctuations close to the phase transition is governed by the interplay between the signal to noise ratio and the system size. These results provide a clear and consistent picture of financial markets as critical systems.Comment: 4 pages, 4 figure

Eigenvector localization as a tool to study small communities in online social networks

We present and discuss a mathematical procedure for identification of small "communities" or segments within large bipartite networks. The procedure is based on spectral analysis of the matrix encoding network structure. The principal tool here is localization of eigenvectors of the matrix, by means of which the relevant network segments become visible. We exemplified our approach by analyzing the data related to product reviewing on Amazon.com. We found several segments, a kind of hybrid communities of densely interlinked reviewers and products, which we were able to meaningfully interpret in terms of the type and thematic categorization of reviewed items. The method provides a complementary approach to other ways of community detection, typically aiming at identification of large network modules

Cracking Piles of Brittle Grains

A model which accounts for cracking avalanches in piles of grains subject to external load is introduced and numerically simulated. The stress is stochastically transferred from higher layers to lower ones. Cracked areas exhibit various morphologies, depending on the degree of randomness in the packing and on the ductility of the grains. The external force necessary to continue the cracking process is constant in wide range of values of the fraction of already cracked grains. If the grains are very brittle, the force fluctuations become periodic in early stages of cracking. Distribution of cracking avalanches obeys a power law with exponent $\tau = 2.4 \pm 0.1$.Comment: RevTeX, 6 pages, 7 postscript figures, submitted to Phys. Rev.