Different cognitive profiles for single compared with recurrent fallers without Dementia

Relationships between self-reported retrospective falls and cognitive measures (executive function, reaction time, processing speed, working memory, visual attention) were examined in a population based sample of older adults (n = 658). Two of the choice reaction time tests involved inhibiting responses to either targets of a specific color or location with hand and foot responses. Potentially confounding demographic variables, medical conditions and postural sway were controlled for in logistic regression models, excluding participants with possible cognitive impairment. A factor analysis of cognitive measures extracted factors measuring reaction time, accuracy and inhibition, and visual search. Single fallers did not differ from non-fallers in terms of health, sway or cognitive function, except that they performed worse on accuracy and inhibition. In contrast, recurrent fallers performed worse than non-fallers on all measures. Results suggest that occasional falls in late life may be associated with subtle age-related changes in the pre-frontal cortex leading to failures of executive control, whereas recurrent falling may result from more advanced brain ageing that is associated with generalized cognitive decline.

Linkage and heritability analysis of migraine symptom groupings: A comparison of three different clustering methods on twin data

Migraine is a painful disorder for which the etiology remains obscure. Diagnosis is largely based on International Headache Society criteria. However, no feature occurs in all patients who meet these criteria, and no single symptom is required for diagnosis. Consequently, this definition may not accurately reflect the phenotypic heterogeneity or genetic basis of the disorder. Such phenotypic uncertainty is typical for complex genetic disorders and has encouraged interest in multivariate statistical methods for classifying disease phenotypes. We applied three popular statistical phenotyping methods—latent class analysis, grade of membership and grade of membership “fuzzy” clustering (Fanny)—to migraine symptom data, and compared heritability and genome-wide linkage results obtained using each approach. Our results demonstrate that different methodologies produce different clustering structures and non-negligible differences in subsequent analyses. We therefore urge caution in the use of any single approach and suggest that multiple phenotyping methods be used.

Different approaches to reduce shaft voltage in AC generators

This paper presents several shaft voltage reduction techniques for doubly-fed induction generators in wind turbine applications. These techniques includes: pulse width modulated voltage without zero vectors, multi-level inverters with proper PWM strategy, better generator design to minimize effective capacitive couplings in shaft voltage, active common-mode filter, reducing dc-link voltage and increasing modulation index. These methods have been verified with mathematical analysis and simulations.

PDMS spreading morphological patterns on substrates of different hydrophilicity in air vacuum and water

In paper has been to investigate the morphological patterns and kinetics of PDMS spreading on silicon wafer using combination of techniques like ellipsometry, atomic force microscope (AFM), scanning electron microscope (SEM) and optical microscopy. A macroscopic silicone oil drops as well as PDMS water based emulsions were studied after deposition on a flat surface of silicon wafer in air, water and vacuum. our own measurements using an imaging ellipsometer, which also clearly shows the presence of a precursor film. The diffusion constant of this film, measured with a 60 000 cS PDMS sample spreading on a hydrophilic silicon wafer, is Df = 1.4  10-11 m2/s. Regardless of their size, density and method of deposition, droplets on both types of wafer (hydrophilic and hydrophobic) flatten out over a period of many hours, up to 3 days. During this process neighbouring droplets may coalesce, but there is strong evidence that some of the PDMS from the droplets migrates into a thin, continuous film that covers the surface in between droplets. The thin film appears to be ubiquitous if there has been any deposition of PDMS. However, this statement needs further verification. One question is whether the film forms immediately after forced drying, or whether in some or all cases it only forms by spreading from isolated droplets as they slowly flatten out.

A comparison of different methods to determine diffusion length in dye-sensitized solar cells

A new steady state method for determination of the electron diffusion length in dye-sensitized solar cells (DSCs) is described and illustrated with data obtained using cells containing three different types of electrolyte. The method is based on using near-IR absorbance methods to establish pairs of illumination intensity for which the total number of trapped electrons is the same at open circuit (where all electrons are lost by interfacial electron transfer) as at short circuit (where the majority of electrons are collected at the contact). Electron diffusion length values obtained by this method are compared with values derived by intensity modulated methods and by impedance measurements under illumination. The results indicate that the values of electron diffusion length derived from the steady state measurements are consistently lower than the values obtained by the non steady-state methods. For all three electrolytes used in the study, the electron diffusion length was sufficiently high to guarantee electron collection efficiencies greater than 90%. Measurement of the trap distributions by near-IR absorption confirmed earlier observations of much higher electron trap densities for electrolytes containing Li+ ions. It is suggested that the electron trap distributions may not be intrinsic properties of the TiO2 nanoparticles, but may be associated with electron-ion interactions.

On the use of different spatial reference frames for movement control

Previous work has shown that amplitude and direction are two independently controlled parameters of aimed arm movements, and performance, therefore, suffers when they must be decomposed into Cartesian coordinates. We now compare decomposition into different coordinate systems. Subjects pointed at visual targets in 2-D with a cursor, using a two-axis joystick or two single-axis joysticks. In the latter case, joystick axes were aligned with the subjects’ body axes, were rotated by –45°, or were oblique (i.e., one axis was in an egocentric frame and the other was rotated by –45°). Cursor direction always corresponded to joystick direction. We found that compared with the two-axis joystick, responses with single-axis joysticks were slower and less accurate when the axes were oriented egocentrically; the deficit was even more pronounced when the axes were rotated and was most pronounced when they were oblique. This confirms that decomposition of motor commands is computationally demanding and documents that this demand is lowest for egocentric, higher for rotated, and highest for oblique coordinates. We conclude that most current vehicles use computationally demanding man–machine interfaces.

Factors influencing oncology nurses' approaches to accommodating cultural needs in palliative care

Aims and objectives: The purpose of this study is to explore the social construction of cultural issues in palliative care amongst oncology nurses. ---------- Background: Australia is a nation composed of people from different cultural origins with diverse linguistic, spiritual, religious and social backgrounds. The challenge of working with an increasingly culturally diverse population is a common theme expressed by many healthcare professionals from a variety of countries. ---------- Design: Grounded theory was used to investigate the processes by which nurses provide nursing care to cancer patients from diverse cultural backgrounds. ---------- Methods: Semi-structured interviews with seven Australian oncology nurses provided the data for the study; the data was analysed using grounded theory data analysis techniques. ---------- Results: The core category emerging from the study was that of accommodating cultural needs. This paper focuses on describing the series of subcategories that were identified as factors which could influence the process by which nurses would accommodate cultural needs. These factors included nurses' views and understandings of culture and cultural mores, their philosophy of cultural care, nurses' previous experiences with people from other cultures and organisational approaches to culture and cultural care. ---------- Conclusions: This study demonstrated that previous experiences with people from other cultures and organisational approaches to culture and cultural care often influenced nurses' views and understandings of culture and cultural mores and their beliefs, attitudes and behaviours in providing cultural care. ---------- Relevance to clinical practice: It is imperative to appreciate how nurses' experiences with people from other cultures can be recognised and built upon or, if necessary, challenged. Furthermore, nurses' cultural competence and experiences with people from other cultures need to be further investigated in clinical practice.

Healthy children, healthy planet : the case for transformative education in schools and early childhood from an Australian perspective

Climate change is an urgent global public health issue with substantial predicted impacts in the coming decades. Concurrently, global burden of disease studies highlight problems such as obesity, mental health problems and a range of other chronic diseases, many of which have origins in childhood. There is a unique opportunity to engage children in both health promotion and education for sustainability during their school years to help ameliorate both environmental and health issues. Evidence exists for the most effective ways to do this, through education that is empowering, action orientated and relevant to children’s day to day interests and concerns, and by tailoring such education to different educational sectors. The aim of this discussion paper is to argue the case for sustainability education in schools that links with health promotion and that adopts a practical approach to engaging children in these important public health and environmental issues. We describe two internationally implemented whole-school reform movements, Health Promoting Schools (HPS) and Sustainable Schools (SS) which seek to operationalise transformative educational processes. Drawing on international evidence and Australian case examples, we contend that children’s active involvement in such processes is not only educationally engaging and rewarding, it also contributes to human and environmental resilience and health. Further, school settings can play an important ecological public health role, incubating and amplifying the socially transformative changes urgently required to create pathways to healthy, just and sustainable human futures, on a viable planet.

The contribution of different androgen receptor domains to receptor dimerization and signaling

The androgen receptor (AR) is a ligand-activated transcription factor of the nuclear receptor superfamily that plays a critical role in male physiology and pathology. Activated by binding of the native androgens testosterone and 5-dihydrotestosterone, the AR regulates transcription of genes involved in the development and maintenance of male phenotype and male reproductive function as well as other tissues such as bone and muscle. Deregulation of AR signaling can cause a diverse range of clinical conditions, including the X-linked androgen insensitivity syndrome, a form of motor neuron disease known as Kennedy’s disease, and male infertility. In addition, there is now compelling evidence that the AR is involved in all stages of prostate tumorigenesis including initiation, progression, and treatment resistance. To better understand the role of AR signaling in the pathogenesis of these conditions, it is important to have a comprehensive understanding of the key determinants of AR structure and function. Binding of androgens to the AR induces receptor dimerization, facilitating DNA binding and the recruitment of cofactors and transcriptional machinery to regulate expression of target genes. Various models of dimerization have been described for the AR, the most well characterized interaction being DNA-binding domain- mediated dimerization, which is essential for the AR to bind DNA and regulate transcription. Additional AR interactions with potential to contribute to receptor dimerization include the intermolecular interaction between the AR amino terminal domain and ligand-binding domain known as the N-terminal/C-terminal interaction, and ligand-binding domain dimerization. In this review, we discuss each form of dimerization utilized by the AR to achieve transcriptional competence and highlight that dimerization through multiple domains is necessary for optimal AR signaling.

Alternative explanations of the volatility trend : Are they really that different?

We analyse the puzzling behavior of the volatility of individual stock returns around the turn of the Millennium. There has been much academic interest in this topic, but no convincing explanation has arisen. Our goal is to pull together the many competing explanations currently proposed in the literature to delermine which, if any, are capable of explaining the volatility trend. We find that many of the different explanations capture the same unusual trend around the Millennium. We find that many of the variables are very highly correlated and it is thus difficult to disentangle their relalive ability to exlplain the time-series behavior in volatility. It seems thai all of the variables that track average volatility well do so mainly by capturing changes in the post-1994 period. These variables have no time-series explanatory power in the pre-1995 years, questioning the underlying idea that any of the explanations currently plesented in the literature can track the trend in volatility over long periods.

Density variation of different shaped food particulates in fluid bed drying : empirical models

Three particular geometrical shapes of parallelepiped, cylindrical and spheres were selected from potatoes (aspect ratio = 1:1, 2:1, 3:1), cut beans (length:diameter = 1:1, 2:1, 3:1) and peas respectively. The density variation of food particulates was studied in a batch fluidised bed dryer connected to a heat pump dehumidifier system. Apparent density and bulk density were evaluated with non-dimensional moisture at three different drying temperatures of 30, 40 and 50 o C. Relative humidity of hot air was kept at 15% in all drying temperatures. Several empirical relationships were developed for the determination of changes in densities with the moisture content. Simple mathematical models were obtained to relate apparent density and bulk density with moisture content.

A quasi-stationary approach to drying kinetics of different shaped food particulates in a heat pump assisted by fluid bed dryer

Experiments were undertaken to study drying kinetics of different shaped moist food particulates during heat pump assisted fluidised bed drying. Three particular geometrical shapes of parallelepiped, cylindrical and spheres were selected from potatoes (aspect ratio = 1:1, 2:1, 3:1), cut beans (length: diameter = 1:1, 2:1, 3:1) and peas respectively. A batch fluidised bed dryer connected to a heat pump system was used for the experimentation. A Heat pump and fluid bed combination was used to increase overall energy efficiency and achieve higher drying rates. Drying kinetics, were evaluated with non-dimensional moisture at three different drying temperatures of 30, 40 and 50o C. Due to complex hydrodynamics of the fluidised beds, drying kinetics are dryer or material specific. Numerous mathematical models can be used to calculate drying kinetics ranging from analytical models with simplified assumptions to empirical models built by regression using experimental data. Empirical models are commonly used for various food materials due to their simpler approach. However problems in accuracy, limits the applications of empirical models. Some limitations of empirical models could be reduced by using semi-empirical models based on heat and mass transfer of the drying operation. One such method is the quasi-stationary approach. In this study, a modified quasi-stationary approach was used to model drying kinetics of the cylindrical food particles at three drying temperatures.