The Stroop revisited: a meta-analysis of interference control in AD/HD

Background: An inhibition deficit, including poor interference control, has been implicated as one of the core deficits in AD/HD. Interference control is clinically measured by the Stroop Colour-Word Task. The aim of this meta-analysis was to investigate the strength of an interference deficit in AD/HD as measured by the Stroop Colour-Word Task and to assess the role of moderating variables that could explain the results. These moderating variables included: methods of calculating the interference score, comorbid reading and psychiatric disorders, AD/HD-subtypes, gender, age, intellectual functioning, medication, and sample size. Methods: Seventeen independent studies were located including 1395 children, adolescents, and young adults, in the age range of 6-27 years. A meta-analysis was conducted to assess the effect sizes for the scores on the word and the colour card as well as the interference score. Results: Children with AD/HD performed more poorly on all three dependent variables. The effect sizes for word reading (d = .49) and colour naming (d = .58) were larger and more homogeneous than the effect size for the interference score (d = .35). The method used to calculate the interference score strongly influenced the findings for this measure. When interference control was calculated as the difference between the score on the colour card minus the score on the colour-word card, no differences were found between AD/HD groups and normal control groups. Discussion: The Stroop Colour-Word Task, in standard form, does not provide strong evidence for a deficit in interference control in AD/HD. However, the Stroop Colour-Word Task may not be a valid measure of interference control in AD/HD and alternative methodologies may be needed to test this aspect of the inhibitory deficit model in AD/HD. © Association for Child Psychology Psychiatry, 2004

Group theoretical analysis of symmetry breaking in two-dimensional quantum dots

We present a group theoretical study of the symmetry-broken unrestricted Hartree-Fock orbitals and electron densities in the case of a two-dimensional N-electron single quantum dot (with and without an external magnetic field). The breaking of rotational symmetry results in canonical orbitals that (1) are associated with the eigenvectors of a Hueckel hamiltonian having sites at the positions determined by the equilibrium molecular configuration of the classical N-electron problem, and (2) transform according to the irreducible representations of the point group specified by the discrete symmetries of this classical molecular configuration. Through restoration of the total-spin and rotational symmetries via projection techniques, we show that the point-group discrete symmetry of the unrestricted Hartree-Fock wave function underlies the appearance of magic angular momenta (familiar from exact-diagonalization studies) in the excitation spectra of the quantum dot. Furthermore, this two-step symmetry-breaking/symmetry-restoration method accurately describes the energy spectra associated with the magic angular momenta.Comment: A section VI.B entitled "Quantitative description of the lowest rotational band" has been added. 16 pages. Revtex with 10 EPS figures. A version of the manuscript with high quality figures is available at http://calcite.physics.gatech.edu/~costas/uhf_group.html For related papers, see http://www.prism.gatech.edu/~ph274c

Advance Care Planning for frail older adults: Findings on costs in a cluster randomised controlled trial

Background: Advance Care Planning aims at improving alignment of care with patients’ preferences. This may affect costs of medical care. Aim: To determine the costs of an Advance Care Planning programme and its effects on the costs of medical care and on concordance of care with patients’ preferences. Design/settings/participants: In a cluster randomised trial, 16 residential care homes were randomly allocated to the intervention group, where frail, older participants were offered facilitated Advance Care Planning conversations or to the control group. We calculated variable costs of Advance Care Planning per participant including personnel and travel costs of facilitators. Furthermore, we assessed participants’ healthcare use during 12 months applying a broad perspective (including medical care, inpatient days in residential care homes, home care) and calculated costs of care per participant. Finally, we investigated whether treatment goals were in accordance with preferences. Analyses were conducted for 97 participants per group. Trial registration number: NTR4454. Results: Average variable Advance Care Planning costs were €76 per participant. The average costs of medical care were not significantly different between the intervention and control group (€2360 vs €2235, respectively, p = 0.36). Costs of inpatient days in residential care homes (€41,

Prevalence of potential drug-drug interactions in the intensive care unit of a Brazilian teaching hospital

Abstract Patients in intensive care unit are prescribed large numbers of drugs, highlighting the need to study potential Drug-Drug Interactions in this environment. The aim of this study was to delineate the prevalence and risk of potential drug-drug interactions between medications administered to patients in an ICU. This cross-sectional observational study was conducted during 12 months, in an adult ICU of a teaching hospital. Inclusion criteria were: prescriptions with 2 or more drugs of patients admitted to the ICU for > 24 hours and age of ≥18 years. Potential Drug-Drug Interactions were quantified and classified through MicromedexTM database. The 369 prescriptions included in this study had 205 different drugs, with an average of 13.04 ± 4.26 (mean ± standard deviation) drugs per prescription. Potential Drug-Drug Interactions were identified in 89% of these, with an average of 5.00 ± 5.06 interactions per prescription. Of the 405 different pairs of potentially interacting drugs identified, moderate and major interactions were present in 74% and 67% of prescriptions, respectively. The most prevalent interaction was between dipyrone and enoxaparin (35.8%), though its clinical occurrence was not observed in this study. The number of potential Drug-Drug Interactions showed significant positive correlations with the length of stay in the intensive care unit, and with the number of prescribed drugs. Acknowledging the high potential for Drug-Drug Interactions in the ICU represents an important step toward improving patient safety and best therapy results

Some aspects of the Liouville equation in mathematical physics and statistical mechanics

This paper presents some mathematical aspects of Classical Liouville theorem and we have noted some mathematical theorems about its initial value problem. Furthermore, we have implied on the formal frame work of Stochastic Liouville equation (SLE)