Three Cases of Frontal Meningiomas Presenting Psychiatrically

The clinical presentation of three patients with meningiomas at different frontal sites is described. They had been ill for 3, 25, and 43 years before the tumour was demonstrated radiologically. Apathy, incontinence, dementia, and fits were seen in association with middle and superior frontal lesions, and may be mistaken for symptoms of involutional depression or presenile cerebral atrophy. In contrast, excitement and hallucinosis were seen in association with a basal frontal lesion, and may mimic psychotic syndromes like hypomania and schizophrenia, particularly if the tumour encroaches on the third ventricle and adjacent structures. Irreversible loss of myelin and axons in the frontal areas of brain surrounding the tumour may have contributed to the clinical picture of the syndrome shown by these patients.     

Cool and Hot Executive Function Impairments in Violent Offenders with Antisocial Personality Disorder with and without Psychopathy

Background

Impairments in executive function characterize offenders with antisocial personality disorder (ASPD) and offenders with psychopathy. However, the extent to which those impairments are associated with ASPD, psychopathy, or both is unknown.

Methods

The present study examined 17 violent offenders with ASPD and psychopathy (ASPD+P), 28 violent offenders with ASPD without psychopathy (ASPD−P), and 21 healthy non-offenders on tasks assessing cool (verbal working memory and alteration of motor responses to spatial locations) and hot (reversal learning, decision-making under risk, and stimulus-reinforcement-based decision-making) executive function.

Results

In comparison to healthy non-offenders, violent offenders with ASPD+P and those with ASPD−P showed similar impairments in verbal working memory and adaptive decision-making. They failed to learn from punishment cues, to change their behaviour in the face of changing contingencies, and made poorer quality decisions despite longer periods of deliberation. Intriguingly, the two groups of offenders did not differ significantly from the non-offenders in terms of their alteration of motor responses to spatial locations and their levels of risk-taking, indicated by betting, and impulsivity, measured as delay aversion. The performance of the two groups of offenders on the measures of cool and hot executive function did not differ, indicating shared deficits.

Conclusions

These documented impairments may help to explain the persistence of antisocial behaviours despite the known risks of the negative consequences of such behaviours.     

Magno- and Parvocellular Contrast Responses in Varying Degrees of Autistic Trait

Autistic tendency has been associated with altered visual perception, especially impaired visual motion sensitivity and global/local integration, as well as enhanced visual search and local shape recognition. However, the neurophysiological mechanisms underlying these abnormalities remain poorly defined. The current study recruited 29 young adults displaying low, middle or high autistic trait as measured by Baron-Cohen''s Autism spectrum Quotient (AQ), and measured motion coherence thresholds psychophysically, with manipulation of dot lifetime and stimulus contrast, as well as nonlinear cortical visual evoked potentials (VEPs) over a range of temporal luminance contrast levels from 10% to 95%. Contrast response functions extracted from the major first order and second order Wiener kernel peaks of the VEPs showed consistent variation with AQ group, and Naka-Rushton fits enabled contrast gain and semi-saturation contrasts to be elicited for each peak. A short latency second order response (previously associated with magnocellular processing) with high contrast gain and a saturating contrast response function showed higher amplitude for the High AQ (compared with Mid and Low groups) indicating poorer neural recovery after rapid stimulation. A non-linearity evoked at longer interaction times (previously associated with parvocellular processing) with no evidence of contrast saturation and lower contrast gain showed no difference between autism quotient groups across the full range of stimulus contrasts. In addition, the short latency first order response and a small, early second order second slice response showed gain and semi-saturation parameters indicative of magnocellular origin, while the longer latency first order response probably reflects a mixture of inputs (including feedback from higher cortical areas). Significant motion coherence (AQ group) * (dot lifetime) interactions with higher coherence threshold for limited dot lifetime stimuli is consistent with atypical magnocellular functioning, however psychophysical performance for those with High AQ is not explained fully, suggesting that other factors may be involved.     

Big houses and small houses: Doing matriliny in West Sumatra

The big house is a potent symbol of rural Minangkabau life, embodying the centrality of Minangkabau women to the continuity and reproduction of the matrilineage. But big houses are not simply sites of social reproduction. Mothers and daughters negotiate and contest the ties of kinship embodied in the big house. Where big houses represented mother's power to control their daughters, national discourses of domesticity have reoriented daughters’ desires toward a house of their own. Daughters assert the importance of their own nuclear households as a way to resist their mother's control. Yet daughters have not become the housewives and mothers of national fantasy. They are reworking matrilineal ideology to gain the right to control their own small houses, ultimately reconstituting big houses in new forms.     

Evolutionary analysis of glycosyl hydrolase family 28 (GH28) suggests lineage-specific expansions in necrotrophic fungal pathogens

Glycosyl hydrolase family 28 (GH28) is a set of structurally related enzymes that hydrolyze glycosidic bonds in pectin, and are important extracellular enzymes for both pathogenic and saprotrophic fungi. Yet, very little is understood about the evolutionary forces driving the diversification of GH28s in fungal genomes. We reconstructed the evolutionary history of family GH28 in fungi by examining the distribution of GH28 copy number across the phylogeny of fungi, and by reconstructing the phylogeny of GH28 genes. We also examined the relationship between lineage-specific GH28 expansions and fungal ecological strategy, testing the hypothesis that GH28 evolution in fungi is driven by ecological strategy (pathogenic vs. non-pathogenic) and pathogenic niche (necrotrophic vs. biotrophic). Our results showed that GH28 phylogeny of Ascomycota and Basidiomycota sequences was structured by specific biochemical function, with endo-polygalacturonases and endo-rhamnogalacturonases forming distinct, apparently ancient clades, while exo-polygalacturonases are more widely distributed. In contrast, Mucoromycotina and Stramenopile sequences formed taxonomically-distinct clades. Large, lineage-specific variation in GH28 copy number indicates that the evolution of this gene family is consistent with the birth-and-death model of gene family evolution, where diversity of GH28 loci within genomes was generated through multiple rounds of gene duplication followed by functional diversification and loss of some gene family members. Although GH28 copy number was correlated with genome size, our findings suggest that ecological strategy also plays an important role in determining the GH28 repertoire of fungi. Both necrotrophic and biotrophic fungi have larger genomes than non-pathogens, yet only necrotrophs possess more GH28 enzymes than non-pathogens. Hence, lineage-specific GH28 expansion is the result of both variation in genome size across fungal species and diversifying selection within the necrotrophic plant pathogen ecological niche. GH28 evolution among necrotrophs has likely been driven by a co-evolutionary arms race with plants, whereas the need to avoid plant immune responses has resulted in purifying selection within biotrophic fungi.