584 research outputs found
The role of acquaintanceship in the perception of child behaviour problems
The role of acquaintanceship with the child on reports of child behaviour by different informants was examined within the framework of a general theory of personality judgment. Mothers of referred children and group-care workers rated videotaped behaviour samples of a well known and an unknown child in the clinic. Independent observers also rated the videotapes. In line with the acquaintanceship hypothesis, mothers were found to perceive more behaviour problems than independent observers when rating well known children but not unknown children. Contrary to the acquaintanceship hypothesis, however, the group-care workers in our study reported more behaviour problems than the other informants regardless of their acquaintance with the children. The clinical and methodological implications of these findings are discussed
State attachment variability across distressing situations in middle childhood
Contemporary research suggests that attachment has both a trait-like, stable component, and a state-like component that varies across contexts. In the current study, we assessed state attachment variability across comparably distressing situations in middle childhood. In two samples, children reported their expectations of maternal support in each situation. Additionally, we administered trait attachment and psychological well-being measures. Results indicated that, overall, children varied in their expectations across situations: more than half of the variance was explained by intra-individual differences across situations. Results revealed two components underlying variability: a Signal-and-Support component reflecting expectations of support-seeking and receiving, and a Back-on-Track component reflecting expectations of stress reduction and comfort. State attachment variability was related to individual differences in trait attachment: children who are more securely attached at the trait level, overall appear to vary less in their state attachment, likely due to their high mean state attachment scores across situations. When the mean state attachment scores are accounted for, more securely attached children seem to vary more, suggesting that their state attachment expectations are more sensitive to contextual fluctuations. Importantly, degree of state attachment variability explained psychological well-being over and above trait attachment
Clinical implications of food-drug interactions with small-molecule kinase inhibitors
During the past two decades, small-molecule kinase inhibitors have proven to be valuable in the treatment of solid and haematological tumours. However, because of their oral administration, the intrapatient and interpatient exposure to small-molecule kinase inhibitors (SMKIs) is highly variable and is affected by many factors, such as concomitant use of food and herbs. Food-drug interactions are capable of altering the systemic bioavailability and pharmacokinetics of these drugs. The most important mechanisms underlying food-drug interactions are gastrointestinal drug absorption and hepatic metabolism through cytochrome P450 isoenzymes. As food-drug interactions can lead to therapy failure or severe toxicity, knowledge of these interactions is essential. This Review provides a comprehensive overview of published studies involving food-drug interactions and herb-drug interactions for all registered SMKIs up to Oct 1, 2019. We critically discuss US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines concerning food-drug interactions and offer clear recommendations for their management in clinical practice
Piecewise Linear Models for the Quasiperiodic Transition to Chaos
We formulate and study analytically and computationally two families of
piecewise linear degree one circle maps. These families offer the rare
advantage of being non-trivial but essentially solvable models for the
phenomenon of mode-locking and the quasi-periodic transition to chaos. For
instance, for these families, we obtain complete solutions to several questions
still largely unanswered for families of smooth circle maps. Our main results
describe (1) the sets of maps in these families having some prescribed rotation
interval; (2) the boundaries between zero and positive topological entropy and
between zero length and non-zero length rotation interval; and (3) the
structure and bifurcations of the attractors in one of these families. We
discuss the interpretation of these maps as low-order spline approximations to
the classic ``sine-circle'' map and examine more generally the implications of
our results for the case of smooth circle maps. We also mention a possible
connection to recent experiments on models of a driven Josephson junction.Comment: 75 pages, plain TeX, 47 figures (available on request
The Exact Ground State of the Frenkel-Kontorova Model with Repeated Parabolic Potential: I. Basic Results
The problem of finding the exact energies and configurations for the
Frenkel-Kontorova model consisting of particles in one dimension connected to
their nearest-neighbors by springs and placed in a periodic potential
consisting of segments from parabolas of identical (positive) curvature but
arbitrary height and spacing, is reduced to that of minimizing a certain convex
function defined on a finite simplex.Comment: 12 RevTeX pages, using AMS-Fonts (amssym.tex,amssym.def), 6
Postscript figures, accepted by Phys. Rev.
Polydispersity and ordered phases in solutions of rodlike macromolecules
We apply density functional theory to study the influence of polydispersity
on the stability of columnar, smectic and solid ordering in the solutions of
rodlike macromolecules. For sufficiently large length polydispersity (standard
deviation ) a direct first-order nematic-columnar transition is
found, while for smaller there is a continuous nematic-smectic and
first-order smectic-columnar transition. For increasing polydispersity the
columnar structure is stabilized with respect to solid perturbations. The
length distribution of macromolecules changes neither at the nematic-smectic
nor at the nematic-columnar transition, but it does change at the
smectic-columnar phase transition. We also study the phase behaviour of binary
mixtures, in which the nematic-smectic transition is again found to be
continuous. Demixing according to rod length in the smectic phase is always
preempted by transitions to solid or columnar ordering.Comment: 13 pages (TeX), 2 Postscript figures uuencode
Boundaries of Disk-like Self-affine Tiles
Let be a disk-like self-affine tile generated by an
integral expanding matrix and a consecutive collinear digit set , and let be the characteristic polynomial of . In the
paper, we identify the boundary with a sofic system by
constructing a neighbor graph and derive equivalent conditions for the pair
to be a number system. Moreover, by using the graph-directed
construction and a device of pseudo-norm , we find the generalized
Hausdorff dimension where
is the spectral radius of certain contact matrix . Especially,
when is a similarity, we obtain the standard Hausdorff dimension where is the largest positive zero of
the cubic polynomial , which is simpler than
the known result.Comment: 26 pages, 11 figure
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