Preschoolers' body-knowledge inaccuracy: perceptual self-deficit and attitudinal bias

Body image research with young children has typically examined their body satisfaction and overlooked developmental theories pertaining to their emergent body-knowledge. Though existing research suggests that preschoolers do demonstrate anti-fat attitudes and weight-related stigmatisation, body dissatisfaction can be difficult to assess in preschoolers due to developmental differences in their (i) ability to perceive their actual body size accurately and (ii) make comparisons with a hypothetical ideal. We review current findings on the attitudinal component of body image in preschoolers, together with findings on the accuracy of their body size perceptions and their emergent body awareness abilities. Such an integration of the cognitive development literature is key to identifying when and how young children understand their physical size and shape; this in turn is critical for informing methodological design targeted at assessing body dissatisfaction and anti-fat attitudes in early childhood.

Beyond deficit models of learning mathematics : Socio-cultural directions for change and research

Major paradigmatic changes in mathematics education research are drawing attention to new perspectives on learning. Whereas deficit models were previously in the foreground of research designs, these have been replaced by a wide variety of theoretical directions for studying diverse approaches to learning mathematics. There is now an acceptance of the need for richness and variety in research practices so that approaches can be studied, compared and mutually applied and improved. Psychological and quantitative approaches and methods are now increasingly complemented, or even replaced, by new directions that rely on social and anthropological theories and methods. Rather than reviving ideas about deficit research in mathematics education, the aim of this chapter is to present some socio-cultural perspectives of mathematics learning, and to show how these perspectives go beyond the deficit model of learning. Framing the main traditional markers of discrimination in school mathematics—gender, social class and ethnicity—in a perspective of social justice, the chapter concludes with a reflection on equality in terms of the democratic principle of meritocracy in mathematics education.

Hoarding in attention deficit hyperactivity disorder: Understanding the comorbidity

Abstract
Hoarding disorder has a frequent co-occurrence with attention-deficit/hyperactivity disorder (ADHD). An accurate understanding of the comorbidity between hoarding disorder and ADHD remains unclear but is essential to inform appropriate assessment, prevention and treatment approaches. This paper will provide a review of potential comorbidity models and aetiological mechanisms implicated in both disorders in order to inform understanding of the nature of the comorbidity between hoarding disorder and ADHD. A correlated liabilities model is identified that implicates genetic, neurological, and executive functioning factors in the development and maintenance of hoarding symptoms in individuals with ADHD.

Sensitivity to MK-801 in phospholipase C-β1 knockout mice reveals a specific NMDA receptor deficit

Phospholipase C-β1 (PLC-β1) is a critical component of multiple signalling pathways downstream of neurotransmitter receptors. Mice lacking this enzyme display a striking behavioural phenotype with relevance to human psychiatric disease. Glutamatergic dysfunction is strongly associated with several abnormal behavioural states and may underlie part of the phenotype of the phospholipase C-β1 knockout (KO) mouse. A heightened response to glutamatergic psychotomimetic drugs is a critical psychosis-related endophenotype, and in this study it was employed as a correlate of glutamatergic dysfunction. Control (n=8) and PLC-β1 KO mice (n=6) were treated with MK-801, a NMDA receptor (NMDAR) antagonist, following either standard housing or environmental enrichment, and the motor function and locomotor activity thus evoked was assessed. In addition, MK-801 binding to the NMDAR was evaluated through radioligand autoradiography in post-mortem tissue (on a drug-naive cohort). We have demonstrated a significantly increased sensitivity to the effects of the NMDA antagonist MK-801 in the PLC-β1 KO mouse. In addition, we found that this mouse line displays reduced hippocampal NMDAR expression, as measured by radioligand binding. We previously documented a reversal of specific phenotypes in this mouse line following housing in an enriched environment. Enrichment did not alter this heightened MK-801 response, nor NMDAR expression, indicating that this therapeutic intervention works on specific pathways only. These findings demonstrate the critical role of the glutamatergic system in the phenotype of the PLC-β1 KO mouse and highlight the role of these interconnected signalling pathways in schizophrenia-like behavioural disruption. These results also shed further light on the capacity of environmental factors to modulate subsets of these phenotypes.

Environmental enrichment ameliorates a motor coordination deficit in a mouse model of Rett syndrome Mecp2 gene dosage effects and BDNF expression

Rett syndrome, commonly associated with mutations of the methyl CpG-binding protein 2 (MECP2) gene, is characterised by an apparently normal early postnatal development followed by deterioration of acquired cognitive and motor coordination skills in early childhood. To evaluate whether environmental factors may influence the disease outcome of Rett syndrome, we tested the effect of environmental enrichment from 4 weeks of age on the behavioural competence of mutant mice harboring a Mecp2 tm1Tam-null allele. Our findings show that enrichment improves motor coordination in heterozygous Mecp2 +/− females but not Mecp2 −/y males. Standard-housed Mecp2 +/− mice had an initial motor coordination deficit on the accelerating rotarod, which improved with training then deteriorated in subsequent weeks. Enrichment resulted in a significant reduction in this coordination deficit in Mecp2 +/− mice, returning the performance to wild-type levels. Brain-derived neurotrophic factor (BDNF) protein levels were 75 and 85% of wild-type controls in standard-housed and environmentally enriched Mecp2 +/− cerebellum, respectively. Mecp2 −/y mice showed identical deficits of cerebellar BDNF (67% of wild-type controls) irrespective of their housing environment. Our findings demonstrate a positive impact of environmental enrichment in a Rett syndrome model; this impact may be dependent on the existence of one functional copy of Mecp2.

The relationship between problem gambling and attention deficit hyperactivity disorder

Recent studies indicate that treatment-seeking problem gamblers display elevated rates of ADHD and that adolescents who screen positive for ADHD are more likely to engage in gambling, develop gambling problems, and experience a greater severity in gambling problems. This study aimed to (a) compare the prevalence of ADHD in treatment-seeking problem gamblers to the general population; (b) investigate the relationships between ADHD and problem gambling severity, cluster B personality disorders, motor impulsivity, alcohol use, substance use, gender, and age; and (c) investigate the degree to which these factors moderate the relationship between ADHD and problem gambling severity. Participants included 214 adults (154 males, 58 females, 2 unspecified) who sought treatment for their gambling problems at a specialist gambling agency in Melbourne, Australia. Almost one-quarter (24.9 %) of treatment-seeking problem gamblers screened positively for ADHD, which was significantly higher than the 14 % prevalence in a community sample. ADHD was significantly positively correlated with problem gambling severity, motor impulsivity, and cluster B personality disorders, but was not associated with alcohol and substance use, gender or age. None of the factors significantly moderated the relationship between ADHD and problem gambling severity. These findings suggest that a considerable proportion of treatment-seeking problem gamblers report ADHD and that their clinical profile is complicated by the presence of high impulsivity and cluster B personality disorders. They highlight the need for specialist gambling agencies to develop screening, assessment, and management protocols for co-occurring ADHD to enhance the effectiveness of treatment.

The effects of government deficit on equilibrium real exchange rates and stock prices

This paper studies the effect of government deficits on equilibrium real exchange rates and stock prices. The theoretical part modifies a two-country cash-in-advance model like used in Lucas(1982) and Sargent(1987) in order to accommodate an exchange rate market and a government that pursues fiscal and monetary policy targets. The implied result is that unanticipated shocks in government deficits raise expectations of both taxes and inflation and, therefore, are associated with real exchange rate devaluations and lower stock prices. This finding is strongly supported by empirical evidence for a group of 19 countries, representing 76% of world production

Indicadores fisiológicos da interação entre deficit hídrico e acidez do solo em cana-de-açúcar

O objetivo deste trabalho foi avaliar os indicadores fisiológicos da interação entre deficit hídrico e acidez do solo em plantas jovens de cana-de-açúcar. As plantas foram submetidas a três tratamentos de disponibilidade hídrica, medidos em percentagem de capacidade de campo (CC) - sem estresse (70% CC), estresse moderado (55% CC) e estresse severo (40% CC); e três tratamentos de acidez no solo, medidos em termos de saturação por bases (V) - baixa acidez (V = 55%), média acidez (V = 33%) e alta acidez (V = 23%). O experimento foi realizado em casa de vegetação a 29,7±4,3ºC e 75±10% UR. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema fatorial 3x3, com quatro repetições. Após 60 dias, foram determinados os teores de solutos compatíveis - trealose, glicina betaína e prolina - na folha diagnóstico e o crescimento inicial da parte aérea. Os solutos compatíveis trealose, glicina betaína e prolina são indicadores do efeito da interação dos estresses hídrico e ácido no solo. O acúmulo dos solutos compatíveis nos tecidos foliares das plantas não é capaz de impedir a redução na produção de matéria seca da cana-de-açúcar, resultante do agravamento nas condições de disponibilidade hídrica e de acidez no solo.

Sugarcane genes differentially expressed during water deficit

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)