Metals in female scalp hair globally and its impact on perceived hair health

Globally, billions of individuals wash their hair in water, which acts as an exogenous metal source. Many studies which measure the metal levels found on human hair specifically aim to remove exogenous materials prior to analysis. Although this is needed when using hair analysis to probe the impact of the local environment on endogenous metal levels, it is not relevant for understanding exactly what is on hair as a result of contact with its daily environment. Understanding these levels are important, as the presence of redox active metals, such as copper and iron, can impact fibre health, either as a result of UV irradiation, or during the hair colouring process. A global hair sampling study of over 300 individuals from nine countries has been performed, and the combined endogenous and exogenous metals analysed. The levels measured vary widely, even within the narrow geography of each hair sampling location. The levels of calcium, magnesium, copper and iron were not correlated, and within each location, there are expected to be individuals with high metal levels. Levels increased from hair root to tip for calcium, magnesium and copper, attributed to hair contact with the environment showing the impact of exogenous metals in the overall levels on hair. Levels of redox metals were comparable between individuals who coloured or did not colour their hair, although water hardness ions were statistically significantly higher for hair colouring individuals. Individuals who perceived their hair health as poor had higher metal levels on their hair. Controlling metals on hair, either by preventing their binding during environmental contact, or through controlling their ability to cause hair damage, should lead to improved consumer perceived hair health.     

Metabolic analysis of the cutaneous fungi Malassezia globosa and M. restricta for insights on scalp condition and dandruff

Dandruff is a global consumer problem, characterized by flaking and scaling of the scalp, accompanied by itch and irritancy. However, the aetiology of the condition remains poorly understood, although there is a strong consensus that the cutaneous fungi Malassezia globosa and M. restricta are a major contributory factor. Although there is a paucity of understanding on how these commensal microorganisms adopt a pathogenic phenotype, a rich source of potential insights now exists in the shape of the recently published whole‐genome sequence of M. globosa, a functional annotation and metabolic reconstruction of which is freely accessible via the integrated microbial genomes (IMG) online community resource ( http://www.hmpdacc-resources.org/cgi-bin/imgm_hmp/main.cgi ). In these studies, we have taken a combined in‐silico and in‐vitro approach to investigate aspects of lipid and amino acid metabolism by M. globosa and M. restricta that have the potential to impact on scalp condition and dandruff. The IMG platform was employed to analyse the metabolism of triacylglycerols and fatty acids, as well as the aromatic amino acid tryptophan, by M. globosa, to investigate pro‐inflammatory pathways linked in the literature to dandruff and pityriasis versicolour, respectively. Results were equivocal, leaving question marks over the ability of M. globosa to fully degrade unsaturated fatty acids and metabolize tryptophan to indole‐3‐pyruvic acid. In‐vitro assay systems were then developed to study the biotransformation of these metabolites by both M. globosa and M. restricta, as well as their effect on human keratinocytes, and the results here indicated that neither unsaturated fatty acids nor indole derivatives are likely to be major aetiological factors in dandruff.     

Subjective and behavioral presence measurement and interactivity in the collaborative augmented reality game TimeWarp

Presence is usually assessed via a variety of subjective and objective measures. However, constraints often result in subjective measurements using questionnaires as a key method of data collection. In this paper we present a study of 44 participants of a collaborative augmented reality game known as TimeWarp which used both subjective and objective behavioral measures. Behavior as coded from video recordings of one scene of the game and self-reports about feelings of presence were compared. Our findings indicate that pointing behavior and verbal responses to the virtual content are correlated negatively to sense of presence. We further investigated the influence of subjectively perceived interactivity on perceived presence. We found that the interaction possibilities perceived by the participants predicted their experience of social presence with the virtual characters in the game. Furthermore, playing together with another person did not result in decreased social presence of the virtual characters. Implications for presence research are discussed.     

Metal Fabrication by Additive Manufacturing Using Laser and Electron Beam Melting Technologies

Selective laser melting (SLM) and electron beam melting (EBM) are relatively new rapid, additive manufac- turing technologies which can allow for the fabrication of complex, multi-functional metal or alloy monoliths by CAD-directed, selective melting of precursor powder beds. By altering the beam parameters and scan strategies, new and unusual, even non-equilibrium microstructures can be produced; including controlled microstructural architectures which ideally extend the contemporary materials science and engineering paradigm relating structure-properties-processing-performance. In this study, comparative examples for SLM and EBM fabricated components from pre-alloyed, atomized precursor powders are presented. These include Cu, Ti–6Al–4V, alloy 625 (a Ni-base superalloy), a Co-base superalloy, and 17-4 PH stainless steel. These systems are characterized by optical metallography, scanning and transmission electron microscopy, and X-ray diffraction.     

System among the corticosteroids: specificity and molecular dynamics

Understanding how structural features determine specific biological activities has often proved elusive. With over 161 000 steroid structures described, an algorithm able to predict activity from structural attributes would provide manifest benefits. Molecular simulations of a range of 35 corticosteroids show striking correlations between conformational mobility and biological specificity. Thus steroid ring A is important for glucocorticoid action, and is rigid in the most specific (and potent) examples, such as dexamethasone. By contrast, ring C conformation is important for the mineralocorticoids, and is rigid in aldosterone. Other steroids that are less specific, or have mixed functions, or none at all, are more flexible. One unexpected example is 11-deoxycorticosterone, which the methods predict (and our activity studies confirm) is not only a specific mineralocorticoid, but also has significant glucocorticoid activity. These methods may guide the design of new corticosteroid agonists and antagonists. They will also have application in other examples of ligand–receptor interactions.     

An investigation of the object relations theory of depression.

The current study investigated a particular aspect shared by a number of theories of depression under the common heading of object relations theory (ORT), namely that depression is associated with a continuing pattern of poor attachment that is laid out in childhood and continues into adulthood. The study examined the relationship between attachment (both parental and peer) and depressive symptoms in young adults (N = 85) of Northern Ireland. Results provided support for the continuity of perceptions of attachment styles across the life span and revealed that perceptions of early attachment experiences, as well as continuing peer attachment styles, appeared to be predictive of current depressive symptoms. More specifically, the analyses revealed a statistically significant positive correlation between perceived quality of current peer attachment and symptoms of depression, as well as a statistically significant negative correlation between self-reported childhood maternal care and symptoms of depression. However, other self-reported measures of childhood attachment were not found to be significant predictors of depressive symptoms (i.e., paternal care, maternal overprotection, paternal overprotection). Taken together, the findings lend some support for this important element of a number of object relations theories, as they pertain to depression. Further empirical research is indicated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)