Development and validation of GT3X accelerometer cut-off points in 5- to 9-year-old children based on indirect calorimetry measurements

The ActiGraph accelerometer is commonly used to measure physical activity in children. Count cut-off points are needed when using accelerometer data to determine the time a person spent in moderate or vigorous physical activity. For the GT3X accelerometer no cut-off points for young children have been published yet. The aim of the current study was thus to develop and validate count cut-off points for young children. Thirty-two children aged 5 to 9 years performed four locomotor and four play activities. Activity classification into the light-, moderate- or vigorous-intensity category was based on energy expenditure measurements with indirect calorimetry. Vertical axis as well as vector magnitude cut-off points were determined through receiver operating characteristic curve analyses with the data of two thirds of the study group and validated with the data of the remaining third. The vertical axis cut-off points were 133 counts per 5 sec for moderate to vigorous physical activity (MVPA), 193 counts for vigorous activity (VPA) corresponding to a metabolic threshold of 5 MET and 233 for VPA corresponding to 6 MET. The vector magnitude cut-off points were 246 counts per 5 sec for MVPA, 316 counts for VPA - 5 MET and 381 counts for VPA - 6 MET. When validated, the current cut-off points generally showed high recognition rates for each category, high sensitivity and specificity values and moderate agreement in terms of the Kappa statistic. These results were similar for vertical axis and vector magnitude cut-off points. The current cut-off points adequately reflect MVPA and VPA in young children. Cut-off points based on vector magnitude counts did not appear to reflect the intensity categories better than cut-off points based on vertical axis counts alone.

Soziale Schichtung und Delinquenz. Eine empirische Anwendung eines Rational Choice-Ansatzes mit Hilfe von Querschnittsdaten des ALLBUS 1990 und 2000

Der oft postulierte Zusammenhang zwischen sozialer Schichtung und Kriminalität ist weder theoretisch abgesichert noch empirisch eindeutig belegt. Ausgehend von der ökonomischen Theorie Gary S. Beckers wird ein erweitertes Modell kriminellen Handelns entwickelt, welches den Einfluss der Schichtzugehörigkeit auf die subjektive Wahrnehmung von Kosten, Nutzen und Entdeckungs-bzw. Erfolgswahrscheinlichkeit krimineller Handlungsalternativen einbezieht. Ferner werden die ebenfalls über die Klassenlage determinierten Anreize (Gelegenheitsstrukturen) und die Internalisierung von Normen („framing“) in das ökonomische Modell integriert. Das Modell wird anhand von Daten aus dem ALLBUS 1990 und 2000 für die Delikte Ladendiebstahl und Steuerbetrug überprüft. Entsprechend den theoretischen Erwartungen kann kein genereller negativer Zusammenhang zwischen Schichtzugehörigkeit und kriminellem Handeln festgestellt werden, wohl aber ein Zusammenhang zwischen Klassenlage und Delikttyp. Sozialstrukturell divergierende Erwartungen hinsichtlich Erfolg einer kriminellen Handlung und Gelegenheitsstrukturen sind bedeutsamer für die Wahl illegaler Handlungsalternativen als Abschreckung durch Strafe oder erwarteter Nutzen aus der Tat. Internalisierte Normvorstellungen machen kriminelle Handlungsalternativen unwahrscheinlich.

3D Conversion using Vanishing Points and Image Warping

We describe a user assisted technique for 3D stereo conversion from 2D images. Our approach exploits the geometric structure of perspective images including vanishing points. We allow a user to indicate lines, planes, and vanishing points in the input image, and directly employ these as constraints in an image warping framework to produce a stereo pair. By sidestepping explicit construction of a depth map, our approach is applicable to more general scenes and avoids potential artifacts of depth-image-based rendering. Our method is most suitable for scenes with large scale structures such as buildings.

Logical omniscience as infeasibility

Logical theories for representing knowledge are often plagued by the so-called Logical Omniscience Problem. The problem stems from the clash between the desire to model rational agents, which should be capable of simple logical inferences, and the fact that any logical inference, however complex, almost inevitably consists of inference steps that are simple enough. This contradiction points to the fruitlessness of trying to solve the Logical Omniscience Problem qualitatively if the rationality of agents is to be maintained. We provide a quantitative solution to the problem compatible with the two important facets of the reasoning agent: rationality and resource boundedness. More precisely, we provide a test for the logical omniscience problem in a given formal theory of knowledge. The quantitative measures we use are inspired by the complexity theory. We illustrate our framework with a number of examples ranging from the traditional implicit representation of knowledge in modal logic to the language of justification logic, which is capable of spelling out the internal inference process. We use these examples to divide representations of knowledge into logically omniscient and not logically omniscient, thus trying to determine how much information about the reasoning process needs to be present in a theory to avoid logical omniscience.

Key points for patient safety in dialysis access.

For more than 15 years, patient safety has been an issue in different domains of medicine. There is evidence for this subject and also a great need for information. First, we should be familiar with the basic terminology such as the relationship between adverse events and errors, and understand the variations of error. In patient management, besides skills and knowledge (evidence-based medicine), the ability (competence) of healthcare professionals to act and react in unexpected situations is key to prevent and treat adverse events. Not only healthcare professionals should be involved in the process but also healthy people in a way that they understand and patients in a way that they are actively involved. This paper will show how a more general view of patient safety can and should be implemented in the daily work of caregivers dealing with dialysis access in different aspects. A key factor to advance in this subject is to be open-minded and sensualized for this topic. The reader should get an idea of how an institution can create a culture of safety.