Small doubling in groups

Let A be a subset of a group G = (G,.). We will survey the theory of sets A with the property that |A.A| <= K|A|, where A.A = {a_1 a_2 : a_1, a_2 in A}. The case G = (Z,+) is the famous Freiman--Ruzsa theorem.Comment: 23 pages, survey article submitted to Proceedings of the Erdos Centenary conferenc

Effects of early neonatal proinflammatory stress on the expression of BDNF transcripts in the brain regions of prepubertal male rats

Early postnatal proinflammatory stress provokes behavioral impairments in adulthood; however, underlying mechanisms are still elusive. Brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroplastic changes in health as well as at pathology. The BDNF gene is transcribed to exon-specific mRNAs and the pattern of their expression depends on stimulus. We suggest that disturbances of exonspecific BDNF mRNA expression in the brain regions after stress induced by proinflammatory stimuli in early postnatal period could be one of the underlying mechanisms of consequent behavioral impairments. Thus, the aim of the study was to investigate the effects of proinflammatory stress in early postnatal ontogeny on the expression of BDNF and the patterns of expression of the BDNF gene in the neocortex and hippocampus of prepubertal male rats. The proinflammatory stress was induced by subcutaneous administration of bacterial lipopolysaccharide (LPS) to rat pups on postnatal days 3 and 5, while BDNF expression was analyzed in 36-day-old rats. BDNF polypeptide concentration was estimated by means of an enzyme-linked immunosorbent assay, while quantitative polymerase chain reaction followed by reverse transcription was used to detect exon-specific BDNF mRNA expression. The levels of BDNF and transcripts, containing common exon IX were similar in the control and LPS-treated rats. In the rats treated with LPS, the level of BDNF mRNA, containing exon IV, was lower in the neocortex, but not in the hippocampus. No changes in the expression of the transcripts containing exons I and VI were observed in any brain structure studied. We suggest that specific alterations in BDNF expression may be involved in the susceptibility to the development of behavioral impairments of animals subjected to early proinflammatory stress

The Tryptophan Hydroxylase Inhibitor LX1031 Shows Clinical Benefit in Patients With Nonconstipating Irritable Bowel Syndrome

Serotonin (5-hydroxytryptamine [5-HT]) has an important role in gastrointestinal function. LX1031 is an oral, locally acting, small molecule inhibitor of tryptophan hydroxylase (TPH). Local inhibition of TPH in the gastrointestinal tract might reduce mucosal production of serotonin (5-HT) and be used to treat patients with nonconstipating irritable bowel syndrome (IBS)

Low temperature thermal expansion of pure and inert gas-doped Fullerite C60

The low temperature (2-24 K) thermal expansion of pure (single crystal and polycrystalline) C60 and polycrystalline C60 intercalated with He, Ne, Ar, and Kr has been investigated using high-resolution capacitance dilatometer. The investigation of the time dependence of the sample length variations on heating shows that the thermal expansion is determined by the sum of positive and negative contributions, which have different relaxation times. The negative thermal expansion usually prevails at helium temperatures. The positive expansion is connected with the phonon thermalization of the system. The negative expansion is caused by reorientation of the C60 molecules. It is assumed that the reorientation is of quantum character. The inert gas impurities affect very strongly the reorientation of the C60 molecules especially at liquid helium temperatures. A temperature hysteresis of the thermal expansion coefficient of Kr- and He- C60 solutions has been revealed. The hysteresis is attributed to orientational polyamorphous transformation in these systems.Comment: 18 pages, 12 figure

Psychiatric inpatient expenditures and public health insurance programmes: analysis of a national database covering the entire South Korean population

<p>Abstract</p> <p>Background</p> <p>Medical spending on psychiatric hospitalization has been reported to impose a tremendous socio-economic burden on many developed countries with public health insurance programmes. However, there has been no in-depth study of the factors affecting psychiatric inpatient medical expenditures and differentiated these factors across different types of public health insurance programmes. In view of this, this study attempted to explore factors affecting medical expenditures for psychiatric inpatients between two public health insurance programmes covering the entire South Korean population: National Health Insurance (NHI) and National Medical Care Aid (AID).</p> <p>Methods</p> <p>This retrospective, cross-sectional study used a nationwide, population-based reimbursement claims dataset consisting of 1,131,346 claims of all 160,465 citizens institutionalized due to psychiatric diagnosis between January 2005 and June 2006 in South Korea. To adjust for possible correlation of patients characteristics within the same medical institution and a non-linearity structure, a Box-Cox transformed, multilevel regression analysis was performed.</p> <p>Results</p> <p>Compared with inpatients 19 years old or younger, the medical expenditures of inpatients between 50 and 64 years old were 10% higher among NHI beneficiaries but 40% higher among AID beneficiaries. Males showed higher medical expenditures than did females. Expenditures on inpatients with schizophrenia as compared to expenditures on those with neurotic disorders were 120% higher among NHI beneficiaries but 83% higher among AID beneficiaries. Expenditures on inpatients of psychiatric hospitals were greater on average than expenditures on inpatients of general hospitals. Among AID beneficiaries, institutions owned by private groups treated inpatients with 32% higher costs than did government institutions. Among NHI beneficiaries, inpatients medical expenditures were positively associated with the proportion of patients diagnosed into dementia or schizophrenia categories. However, for AID beneficiaries, inpatient medical expenditures were positively associated with the proportion of all patients with a psychiatric diagnosis that were AID beneficiaries in a medical institution.</p> <p>Conclusions</p> <p>This study provides evidence that patient and institutional factors are associated with psychiatric inpatient medical expenditures, and that they may have different effects for beneficiaries of different public health insurance programmes. Policy efforts to reduce psychiatric inpatient medical expenditures should be made differently across the different types of public health insurance programmes.</p

Associations of homelessness and residential mobility with length of stay after acute psychiatric admission

Background: A small number of patient-level variables have replicated associations with the length of stay (LOS) of psychiatric inpatients. Although need for housing has often been identified as a cause of delayed discharge, there has been little research into the associations between LOS and homelessness and residential mobility (moving to a new home), or the magnitude of these associations compared to other exposures. Methods: Cross-sectional study of 4885 acute psychiatric admissions to a mental health NHS Trust serving four South London boroughs. Data were taken from a comprehensive repository of anonymised electronic patient records. Analysis was performed using log-linear regression. Results: Residential mobility was associated with a 99% increase in LOS and homelessness with a 45% increase. Schizophrenia, other psychosis, the longest recent admission, residential mobility, and some items on the Health of the Nation Outcome Scales (HoNOS), especially ADL impairment, were also associated with increased LOS. Informal admission, drug and alcohol or other non-psychotic diagnosis and a high HoNOS self-harm score reduced LOS. Including residential mobility in the regression model produced the same increase in the variance explained as including diagnosis; only legal status was a stronger predictor. Conclusions: Homelessness and, especially, residential mobility account for a significant part of variation in LOS despite affecting a minority of psychiatric inpatients; for these people, the effect on LOS is marked. Appropriate policy responses may include attempts to avert the loss of housing in association with admission, efforts to increase housing supply and the speed at which it is made available, and reforms of payment systems to encourage this

Research On and Activities For Mathematically Gifted Students

This Topical Survey offers a brief overview of the current state of research on and activities for mathematically gifted students around the world. This is of interest to a broad readership, including educational researchers, research mathematicians, mathematics teachers, teacher educators, curriculum designers, doctoral students, and other stakeholders. It first discusses research concerning the nature of mathematical giftedness, including theoretical frameworks and methodologies that are helpful in identifying and/or creating mathematically gifted students, which is described in this section. It also focuses on research on and the development of mathematical talent and innovation in students, including connections between cognitive, social and affective aspects of mathematically gifted students. Exemplary teaching and learning practices, curricula and a variety of programs that contribute to the development of mathematical talent, gifts, and passion are described as well as the pedagogy and mathematics content suitable for educating pre-service and in-service teachers of mathematically gifted students. The final section provides a brief summary of the paper along with suggestions for the research, activities, and resources that should be available to support mathematically gifted students and their teachers, parents, and other stakeholders