Explicit formula for the generating series of diagonal 3D rook paths

Let $a_n$ denote the number of ways in which a chess rook can move from a corner cell to the opposite corner cell of an $n \times n \times n$ three-dimensional chessboard, assuming that the piece moves closer to the goal cell at each step. We describe the computer-driven \emph{discovery and proof} of the fact that the generating series $G(x)= \sum_{n \geq 0} a_n x^n$ admits the following explicit expression in terms of a Gaussian hypergeometric function: G(x) = 1 + 6 \cdot \int_0^x \frac{\,\pFq21{1/3}{2/3}{2} {\frac{27 w(2-3w)}{(1-4w)^3}}}{(1-4w)(1-64w)} \, dw.Comment: To appear in "S\'eminaire Lotharingien de Combinatoire

A novel description of ISFET sensitivity with the buffer capacity and double-layer capacitance as key parameters

The pH sensitivity of ISFETs arises from interactions of protons with ISFET gate surface sites. This sensitivity is described by a new simpler model with the intrinsic buffer capacity and the differential capacitance as key parameters. The obtained expression is independent of the models used for the chemical surface equilibria and the charge profile in the solution. The general expression for the sensitivity is elaborated using the site-binding theory and the Gouy-Chapman-Stern theory. The relatively high sensitivity of Ta2O5 ISFETs is explained using this elaborated theory. It is shown that the electrolyte concentration has almost no influence on the sensitivity of Ta2O5 ISFETs

Legal and illegal drug use among female sex workers in bar and club prostitution in Belgium: a quantitative and qualitative study

Aims: This study describes the amounts and effects of drug use in bar and club sex work, and the use of healthcare for the drug-related needs of sex workers (SW). Methods: A cross-sectional study was carried out in Belgium. In a quantitative component, 120 bar and club SW were interviewed face-to-face by means of a semi-structured questionnaire. In a qualitative component, 25 SW were interviewed face-to-face and 5 focus group discussions with key actors professionally involved with the study's subject were conducted. Findings: Many bar and club SW drink frequently alcohol and engage in heavy drinking. Illegal drugs such as cannabis, cocaine and benzodiazepines are also frequently used. The drug use often involves poly or combined drug use. More than one-third experienced a certain degree of dependence on a product and many experienced effects from drug use on their sex work. The study shows that SW have difficulties accessing drug-related healthcare. Conclusions: SW use often legal and illegal drugs. The prevalence and influence of drug use among bar and club SW illustrates the need for drug and sex work related healthcare. Distribution of more information about the risks of drug use, the possible negative effects, and the available drug-related healthcare is needed

Rethinking the Biennial

None Provide

The psychometric properties of a shortened Dutch version of the consequences scale used in the core alcohol and drug survey

<div><p>Background</p><p>Alcohol and drug misuse among college students has been studied extensively and has been clearly identified as a public health problem. Within more general populations alcohol misuse remains one of the leading causes of disease, disability and death worldwide. Conducting research on alcohol misuse requires valid and reliable instruments to measure its consequences. One scale that is often used is the consequences scale in the Core Alcohol and Drug Survey (CADS). However, psychometric studies on the CADS are rare and the ones that do exist report varying results. This article aims to address this imbalance by examining the psychometric properties of a Dutch version of the CADS in a large sample of Flemish university and college students.</p><p>Methods</p><p>The analyses are based on data collected by the inter-university project ‘Head in the clouds’, measuring alcohol use among students. In total, 19,253 students participated (22.1% response rate). The CADS scale was measured using 19 consequences, and participants were asked how often they had experienced these on a 6-point scale. Firstly, the factor structure of the CADS was examined. Two models from literature were compared by performing confirmatory factor analyses (CFA) and were adapted if necessary. Secondly, we assessed the composite reliability as well as the convergent, discriminant and concurrent validity.</p><p>Results</p><p>The two-factor model, identifying personal consequences (had a hangover; got nauseated or vomited; missed a class) and social consequences (got into an argument or fight; been criticized by someone I know; done something I later regretted; been hurt or injured) was indicated to be the best model, having both a good model fit and an acceptable composite reliability. In addition, construct validity was evaluated to be acceptable, with good discriminant validity, although the convergent validity of the factor measuring ‘social consequences’ could be improved. Concurrent validity was evaluated as good.</p><p>Conclusions</p><p>In deciding which model best represents the data, it is crucial that not only the model fit is evaluated, but the importance of factor reliability and validity issues is also taken into account. The two-factor model, identifying personal consequences and social consequences, was concluded to be the best model. This shortened Dutch version of the CADS (CADS_D) is a useful tool to screen alcohol-related consequences among college students.</p></div

Real-time Stage 1 Sleep Detection and Warning System Using a Low-Cost EEG Headset

The goal of this thesis is to design and test a real-time Stage 1 sleep detection and warning system using a low-cost single dry-sensor EEG headset. Such a system would allow aircraft pilots or truck drivers to receive an auditory warning when they are beginning to fall asleep. The device designed in this study records a single EEG signal and filters it into low Alpha (7.5 - 9.25 Hz), high Alpha (10 - 11.75 Hz), low Beta (13 - 16.75 Hz), and high Beta (18 - 29.75 Hz) frequency bands. When the EEG transitions to match that of Stage 1 sleep for a short period of time, the device produces an audible alarm. The system proved 81% effective at detecting sleep in a small sample group. All failures were due to false alarms. Compared to tradition sleep scoring, this device predicted and responded to the onset of drowsiness preceding stage 1 sleep

Taming the Golden Goose: Private Companies, Consumer Geolocation Data, and the Need for a Class Action Regime for Privacy Protection

With the implementation of new geolocation technologies, the boundaries between private versus commercial and secret versus easily ascertainable have vanished. Consumer information that was once very difficult and prohibitively expensive to ascertain, catalogue, and recall is available to companies at the click of a button. Not only that, but the collecting company can share consumer information with other companies even more easily than it can initially collect the information. Today, with the widespread use of smartphone and location-enabled tablet devices, it is possible for location services to determine and plot the location and travel of the device and thereby the travel and habits of the owner. Companies can use the collected customer information to sell products, and they can sell the information to third parties for a variety of both benign and malicious purposes. Meanwhile, skilled hackers can steal consumer information. After analyzing the current legal landscape of consumer privacy law as it relates to geolocation services, this Note argues that US and global consumers need the United States to act. In order to foster trust in corporations and the market, Congress should enact a framework that assures consumers of sufficient protection of those details that consumers hold intrinsically private, such as their personal locations. This Note concludes by examining the bills currently under consideration by Congress and their respective deficiencies