A study of disorder effects in random (Al(x)Ga(1-x)As)(n)(Al(y)Ga(1-y)As)(m) superlattices embedded in a wide parabolic potential

A photoluminescence (PL) study of the individual electron states localized in a random potential is performed in artificially disordered superlattices embedded in a wide parabolic well. The valence band bowing of the parabolic potential provides a variation of the emission energies which splits the optical transitions corresponding to different wells within the random potential. The blueshift of the PL lines emitted by individual random wells, observed with increasing disorder strength, is demonstrated. The variation of temperature and magnetic field allowed for the behavior of the electrons localized in individual wells of the random potential to be distinguished.

Geodynamic evolution of the SW Variscides: Orogenic collapse shown by new tectonometamorphic and isotopic data from western Ossa-Morena Zone, SW Iberia

The pre-Mesozoic geodynamic evolution of SW Iberia has been investigated on the basis of detailed structural analysis, isotope dating, and petrologic study of high-pressure (HP) rocks, revealing the superposition of several tectonometamorphic events: (1) An HP event older than circa 358 Ma is recorded in basic rocks preserved inside marbles, which suggests subduction of a continental margin. The deformation associated with this stage is recorded by a refractory graphite fabric and noncoaxial mesoscopic structures found within the host metasediments. The sense of shear is top to south, revealing thrusting synthetic with subduction (underthrusting) to the north. (2) Recrystallization before circa 358 Ma is due to a regional-scale thermal episode and magmatism. (3) Noncoaxial deformation with top to north sense of shear in northward dipping large-scale shear zones is associated with pervasive hydration and metamorphic retrogression under mostly greenschist facies. This indicates exhumation by normal faulting in a detachment zone confined to the top to north and north dipping shear zones during postorogenic collapse soon after 358 Ma ago (inversion of earlier top to south thrusts). (4) Static recrystallization at circa 318 Ma is due to regional-scale granitic intrusions. Citation: Rosas, F. M., F. O. Marques, M. Ballevre, and C. Tassinari (2008), Geodynamic evolution of the SW Variscides: Orogenic collapse shown by new tectonometamorphic and isotopic data from western Ossa-Morena Zone, SW Iberia, Tectonics, 27, TC6008, doi:10.1029/2008TC002333.

Temporomandibular Disorder in Brazilian Patients: A Preliminary Study

The objective of the current study was to evaluate disease-related beliefs, adherence to treatment, quality of life, coping strategies and cognitive status in a group of Brazilian patients with Temporomandibular Disorder (TMD). Thirty patients were evaluated with a semi-directed interview, the Coping Strategies Inventory, and a Mini-Mental State Examination. Although half (50%) of the patients had known their diagnosis long term, 40% of the sample were not correctly following proposed treatment. All patients had a similar pattern of pain behavior related to TMD, while disease-related beliefs, quality of life and coping strategies were variable. Expectations about treatment also had significant association with treatment adherence. The findings of this study suggest that a more thorough understanding of individual differences in TMD is warranted.

Influence of the microstructure in the collapse of a residual clayey tropical soil

A typical residual clayey soil originating from basalt in southern Brazil has been analyzed in order to assess the influence of wetting-induced deformation and microstructural features on the collapse behavior. Single and double oedometer tests were undertaken on a soil profile to 9 m depth. The results indicated collapsible behaviour at all profile depths. The influence of pre-consolidation stress and pedogenetic factors in the variability of the physical characteristics of the soil and in the magnitude of the collapse was noted. The collapse coefficient has been shown to be related to the both the microaggregate plasma and the varying nature of the pores and their interconnectivity.

Collapse behavior of soil in a Brazilian region affected by a rising water table

Collapsible soils are usually nonsaturated, low density, and metastable-structured soils that are known to exhibit a volume reduction following an episode of moisture increase or suction reduction. This paper describes the collapsible behavior of clayey sand based on controlled soil suction tests carried out on undisturbed samples from the city of Pereira Barreto, in the State of Sao Paulo, Brazil. Foundation settlements due to soil collapse are common in this region and occurred during the filling of the reservoir of the Tres Irmaos Dam, which induced the elevation of the groundwater table in different parts of Pereira Barreto. This paper shows that collapse strains depend on the stress and soil suction acting in the sample and that saturation is not necessary for a collapse to occur. The influence of soil suction, gradual wetting, and the wetting and drying cycle on the collapsible behavior of the soil is also shown and discussed.

Malnourished mice display an impaired hematologic response to granulocyte colony-stimulating factor administration

The aim of this Study was to determine if protein-energy malnutrition Could affect the hematologic response to granulocyte colony-stimulating factor (G-CSF). Swiss mice were fled a low-protein diet containing 4% protein, whereas control mice were fed a 20% protein-containing diet. After the malnourished group lost 20% of their original body weight, the mice were subdivided in 2 treatment groups, and hematopoietic parameters were studied. Mice were injected with either 8 mu g/kg per day of G-CSF or saline twice daily for 4 days. Malnourished mice developed anemia with reticulopenia and leukopenia with depletion of granulocytes and lymphocytes. Both malnourished and control mice treated with G-CSF showed a significant increase in neutrophils; however, in the control group, this increase was more pronounced compared to the malnourished group (4.5-fold and 3.4-fold, respectively). Granulocyte colony-stimulating factor administration increased bone marrow blastic (P < .001) and granulocytic (P < .01) compartments in the controls bill had no significant effect oil these hematopoietic compartments in the Malnourished animals (P = .08 and P = .62, respectively). We report that malnourished mice display an impaired response to G-CSF, which contributes to the decreased production of leukocytes in protein-energy malnutrition. (C) 2008 Elsevier Inc. All rights reserved.

Auditory processing disorder in perisylvian syndrome

We hypothesized that the processing of auditory information by the perisylvian polymicrogyric cortex may be different from the normal cortex. To characterize the auditory processing in bilateral perisylvian syndrome, we examined ten patients with perisylvian polymicrogyria (Group 1) and seven control children (Group 11). Group I was composed by four children with bilateral perisylvian polymicrogyria and six children with bilateral posterior perisylvian polymicrogyria. The evaluation included neurological and neuroimaging investigation, intellectual quotient and audiological assessment (audiometry and behavior auditory tests). The results revealed a statistically significant difference between the groups in the behavioral auditory tests, Such as, digits dichotic test, nonverbal dichotic test (specifically in right attention), and random gap detection/random gap detection expanded tests. Our data showed abnormalities in the auditory processing of children with perisylvian polymicrogyria, suggesting that perisylvian polymicrogyric cortex is functionally abnormal. We also found a correlation between the severity of our auditory findings and the extent of the cortical abnormality. (C) 2009 Elsevier B.V. All rights reserved.

Serious criminal offending and mental disorder - Case linkage study

Background A relationship exists between mental disorder and offending behaviours but the nature and extent of the association remains in doubt. Method Those convicted in the higher courts of Victoria between 1993 and 1995 had their pyschiatric history explored by case linkage to a register listing virtually all contacts with the public psychiatric services. Results Prior psychiatric contact was found in 25% or offenders, but the personality disorder and substance misuse accounted for much of this relationship. Schizophrenia and affective disorders were also over-represented, particularly those with coexisting substance misuse. Conclusions The increased offending in schizophrenia and affective illness is modest and may often be mediated by coexisting substance misuse. The risk of a serious crime being committed by someone with a major mental illness is small and does not justify subjecting them, as a group, to either increased institutional containment or greater coercion.

Saturation mutagenesis of the beta subunit of the human granulocyte-macrophage colony-stimulating factor receptor shows clustering of constitutive mutations, activation of ERK MAP kinase and STAT pathways, and differential beta subunit tyrosine phosphoryl

The high-affinity receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 (IL-3), and IL-5 are heterodimeric complexes consisting of cytokine-specific alpha subunits and a common signal-transducing beta subunit (h beta c). We have previously demonstrated the oncogenic potential of this group of receptors by identifying constitutively activating point mutations in the extracellular and transmembrane domains of h beta c. We report here a comprehensive screen of the entire h beta c molecule that has led to the identification of additional constitutive point mutations by virtue of their ability to confer factor independence on murine FDC-P1 cells. These mutations were clustered exclusively in a central region of h beta c that encompasses the extracellular membrane-proximal domain, transmembrane domain, and membrane-proximal region of the cytoplasmic domain. Interestingly, most h beta c mutants exhibited cell type-specific constitutive activity, with only two transmembrane domain mutants able to confer factor independence on both murine FDC-P1 and BAF-B03 cells. Examination of the biochemical properties of these mutants in FDC-P1 cells indicated that MAP kinase (ERK1/2), STAT, and JAK2 signaling molecules were constitutively activated. In contrast, only some of the mutant beta subunits were constitutively tyrosine phosphorylated. Taken together; these results highlight key regions involved in h beta c activation, dissociate h beta c tyrosine phosphorylation from MAP kinase and STAT activation, and suggest the involvement of distinct mechanisms by which proliferative signals can be generated by h beta c. (C) 1998 by The American Society of Hematology.

Modeling the fluid-flow-induced stress and collapse in a dendritic network

An analytical approach to the stress development in the coherent dendritic network during solidification is proposed. Under the assumption that stresses are developed in the network as a result of the friction resisting shrinkage-induced interdendritic fluid flow, the model predicts the stresses in the solid. The calculations reflect the expected effects of postponed dendrite coherency, slower solidification conditions, and variations of eutectic volume fraction and shrinkage. Comparing the calculated stresses to the measured shear strength of equiaxed mushy zones shows that it is possible for the stresses to exceed the strength, thereby resulting in reorientation or collapse of the dendritic network.

A cell type-specific constitutive point mutant of the common beta-subunit of the human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-3, and IL-5 receptors requires the GM-CSF receptor alpha-subunit for activation

The high affinity receptor for human granulocyte-macrophage colony-stimulating factor (GM-CSF) consists of a cytokine-specific alpha-subunit (hGMR alpha) and a common signal-transducing beta-subunit (hpc) that is shared with the interleukin-3 and -5 receptors, We have previously identified a constitutively active extracellular point mutant of hpc, I374N, that can confer factor independence on murine FDC-P1 cells but not BAF-B03 or CTLL-2 cells (Jenkins, B. J., D'Andrea, R. J., and Gonda, T. J. (1995) EMBO J. 14, 4276-4287), This restricted activity suggested the involvement of cell type-specific signaling molecules in the activation of this mutant. We report here that one such molecule is the mouse GMR alpha (mGMR alpha) subunit, since introduction of mGMR alpha, but not hGMR alpha, into BAF-B03 or CTLL-2 cells expressing the I374N mutant conferred factor independence, Experiments utilizing mouse/human chimeric GMR alpha subunits indicated that the species specificity lies in the extracellular domain of GMRa. Importantly, the requirement for mGMR alpha correlated with the ability of I374N (but not wild-type hpc) to constitutively associate with mGMRa. Expression of I374N in human factor-dependent UT7 cells also led to factor-independent proliferation, with concomitant up-regulation of hGMR alpha surface expression. Taken together, these findings suggest a critical role for association with GMR alpha in the constitutive activity of I374N.

Effect of disorder on quantum phase transitions in anisotropic XY spin chains in a transverse field

We present some exact results for the effect of disorder on the critical properties of an anisotropic XY spin chain in a transverse held. The continuum limit of the corresponding fermion model is taken and in various cases results in a Dirac equation with a random mass. Exact analytic techniques can then be used to evaluate the density of states and the localization length. In the presence of disorder the ferromagnetic-paramagnetic or Ising transition of the model is in the same universality class as the random transverse field Ising model solved by Fisher using a real-space renormalization-group decimation technique (RSRGDT). If there is only randomness in the anisotropy of the magnetic exchange then the anisotropy transition (from a ferromagnet in the x direction to a ferromagnet in the y direction) is also in this universality class. However, if there is randomness in the isotropic part of the exchange or in the transverse held then in a nonzero transverse field the anisotropy transition is destroyed by the disorder. We show that in the Griffiths' phase near the Ising transition that the ground-state energy has an essential singularity. The results obtained for the dynamical critical exponent, typical correlation length, and for the temperature dependence of the specific heat near the Ising transition agree with the results of the RSRODT and numerical work. [S0163-1829(99)07125-8].

Myeloproliferative disorder and leukaemia in mice induced by different classes of constitutive mutants of the human IL-3/IL-5/GM-CSF receptor common beta subunit

Several constitutively active mutant forms of the common β subunit of the human IL-3, IL-5 and GM-CSF receptors (hβc), which enable it to signal in the absence of ligand, have recently been described. Two of these, V449E and I374N, are amino acid substitutions in the transmembrane and extracellular regions of hβc, respectively. A third, FIΔ, contains a 37 amino acid duplication in the extracellular domain. We have shown previously that when expressed in primary murine haemopoietic cells, the extracellular mutants confer factor-independence on cells of the neutrophil and monocyte lineages only, whereas V449E does so on all cell types of the myeloid and erythroid compartments. To study the in vivo effects and leukaemic potential of these mutants, we have expressed all three in mice by bone marrow reconstitution using retrovirally infected donor cells. Expression of the extracellular mutants leads to an early onset, chronic myeloproliferative disorder marked by elevations in the neutrophil, monocyte, erythrocyte and platelet lineages. In contrast, expression of V449E leads to an acute leukaemia-like syndrome of anaemia, thrombocytopaenia and blast cell expansion. These data support the possibility that activating mutations in hβc are involved in haemopoietic disorders in man.

Age-at-first-admission of schizophrenia, bipolar disorder and major depression: Implications of heterogeneity

Age of onset is an important variable when considering the cause and course of mental illnesses. Given the debate about the relationship between psychotic disorders it would be useful to compare age-at-first-admission for ICD schizophrenia and for affective psychoses when the latter is differentiated into 'major depression' and 'bipolar disorder'. Data on age-at-first-admission for Australian-born individuals diagnosed with schizophrenia (ICD 295) or affective psychosis (ICD 296) were extracted from the Queensland Mental Health Statistics System -- a comprehensive, namelinked mental health register. Because the ICD 9 category 296.1 was used to code what is now called "major depressive episode', this group was differentiated from other 296 categorieswhich were considered bipolar disorders. Those receiving more than one diagnoses within these categories were excluded. All distributions show a wide age range of onset from early adolescence into the seventies and eighties. However the modal age-group for major depression ('60-69' for both sexes) is clearly different from bipolar disorder ('20-29' for males; '30- 39' for females), the latter distribution being more similar to the SCZ distribution (which had a model age-group of '20-29' for both sexes). While these distributions were similar for males and females, there were sex differences in the proportions within each diagnostic group: more males with schizophrenia, and more females with bipolar disorder and with major depression. Our results suggest heterogeneity within the affective psychoses as categorised by ICD 9, with bipolar disorder having an age-at-first-admission distribution more similar to schizophrenia than major depression. The Stanley Foundation supported this project.