TY  - JOUR
A1  - Chmielewski, Anna K.
A1  - Dumont, Hanna
A1  - Trautwein, Ulrich
T1  - Tracking Effects Depend on Tracking Type
BT  - An International Comparison of Students’ Mathematics Self-Concept
JF  - American Educational Research Journal
N2  - The aim of the present study was to examine how different types of tracking—
between-school streaming, within-school streaming, and course-by-course
tracking—shape students’ mathematics self-concept. This was done in an
internationally comparative framework using data from the Programme for
International Student Assessment (PISA). After controlling for individual
and track mean achievement, results indicated that generally for students
in course-by-course tracking, high-track students had higher mathematics
self-concepts and low-track students had lower mathematics self-concepts.
For students in between-school and within-school streaming, the reverse pat-
tern was found. These findings suggest a solution to the ongoing debate about
the effects of tracking on students’ academic self-concept and suggest that the
reference groups to which students compare themselves differ according to the
type of tracking.
KW  - academic self-concept
KW  - international comparison
KW  - reference groups
KW  - social comparison
KW  - tracking
Y1  - 2013
UR  - http://journals.sagepub.com/doi/pdf/10.3102/0002831213489843
U6  - https://doi.org/10.3102/0002831213489843
SN  - 0002-8312
VL  - 50
IS  - 5
SP  - 926
EP  - 957
PB  - Sage
CY  - Thousand Oaks, Calif.
ER  - 
TY  - JOUR
A1  - Feldmann, David
A1  - Maduar, Salim R.
A1  - Santer, Mark
A1  - Lomadze, Nino
A1  - Vinogradova, Olga I.
A1  - Santer, Svetlana
T1  - Manipulation of small particles at solid liquid interface
BT  - light driven diffusioosmosis
JF  - Scientific reports
N2  - The strong adhesion of sub-micron sized particles to surfaces is a nuisance, both for removing contaminating colloids from surfaces and for conscious manipulation of particles to create and test novel micro/nano-scale assemblies. The obvious idea of using detergents to ease these processes suffers from a lack of control: the action of any conventional surface-modifying agent is immediate and global. With photosensitive azobenzene containing surfactants we overcome these limitations. Such photo-soaps contain optical switches (azobenzene molecules), which upon illumination with light of appropriate wavelength undergo reversible trans-cis photo-isomerization resulting in a subsequent change of the physico-chemical molecular properties. In this work we show that when a spatial gradient in the composition of trans- and cis- isomers is created near a solid-liquid interface, a substantial hydrodynamic flow can be initiated, the spatial extent of which can be set, e.g., by the shape of a laser spot. We propose the concept of light induced diffusioosmosis driving the flow, which can remove, gather or pattern a particle assembly at a solid-liquid interface. In other words, in addition to providing a soap we implement selectivity: particles are mobilized and moved at the time of illumination, and only across the illuminated area.
KW  - genomic DNA conformation
KW  - photosensitive surfactants
KW  - optical manipulation
KW  - photocontrol
KW  - azobenzene
KW  - films
KW  - gradients
KW  - transport
KW  - tracking
KW  - brushes
Y1  - 2016
U6  - https://doi.org/10.1038/srep36443
SN  - 2045-2322
VL  - 6
PB  - Nature Publishing Group
CY  - London
ER  -