21 research outputs found
Density anomaly in a competing interactions lattice gas model
We study a very simple model of a short-range attraction and an outer shell
repulsion as a test system for demixing phase transition and density anomaly.
The phase-diagram is obtained by applying mean field analysis and Monte Carlo
simulations to a two dimensional lattice gas with nearest-neighbors attraction
and next-nearest-neighbors repulsion (the outer shell). Two liquid phases and
density anomaly are found.
The coexistence line between these two liquid phases meets a critical line
between the fluid and the low density liquid at a tricritical point. The line
of maximum density emerges in the vicinity of the tricritical point, close to
the demixing transition
The Latin American experience of allografting patients with severe aplastic anaemia: real-world data on the impact of stem cell source and ATG administration in HLA-identical sibling transplants
We studied 298 patients with severe aplastic anaemia (SAA) allografted in four Latin American countries. The source of cells
was bone marrow (BM) in 94 patients and PBSCs in 204 patients. Engraftment failed in 8.1% of recipients with no difference
between BM and PBSCs (P = 0.08). Incidence of acute GvHD (aGvHD) for BM and PBSCs was 30% vs 32% (P = 0.18), and for grades
III–IV was 2.6% vs 11.6% (P = 0.01). Chronic GvHD (cGvHD) between BM and PBSCs was 37% vs 59% (P = 0.002) and extensive 5% vs
23.6% (P = 0.01). OS was 74% vs 76% for BM vs PBSCs (P = 0.95). Event-free survival was superior in patients conditioned with
anti-thymocyte globulin (ATG)-based regimens compared with other regimens (79% vs 61%, P = 0.001) as excessive secondary graft
failure was seen with other regimens (10% vs 26%, P = 0.005) respectively. In multivariate analysis, aGvHD II–IV (hazard ratio (HR)
2.50, confidence interval (CI) 1.1–5.6, P = 0.02) and aGvHD III–IV (HR 8.3 CI 3.4–20.2, Po0.001) proved to be independent negative
predictors of survival. In conclusion, BM as a source of cells and ATG-based regimens should be standard because of higher GvHD
incidence with PBSCs, although the latter combining with ATG in the conditioning regimen could be an option in selected high-risk
patient
Socio-economic status affects sentence repetition, but not non-word repetition, in Chilean preschoolers
Sentence repetition and non-word repetition tests are widely-used measures of language processing which are sensitive to language ability. Surprisingly little previous work has investigated whether children’s socio-economic status (SES) affects their sentence and non-word repetition accuracy. This study investigates sentence and non-word repetition using an adaptation of the Grammar and Phonology Screening (GAPS) test. The sample comprised 126 typically-developing Spanish-monolingual Chilean children aged 5;6 from low (n=65) and high (n=61) socioeconomic status (SES) families. The results revealed that the high SES group scored significantly higher than the low SES group in the sentence repetition task, but there was no group difference for non-word repetition. The high SES group also scored significantly higher on a measure of vocabulary comprehension, and when vocabulary comprehension was taken into account, the group difference in sentence repetition was no longer significant. We discuss how the differential effect of SES on sentence and non-word repetition might be explained by differences in the language and cognitive mechanisms involved in the two tasks, and we discuss the clinical implications of our findings