The Science of Galaxy Formation

Our knowledge of the Universe remains discovery-led: in the absence of adequate physics-based theory, interpretation of new results requires a scientific methodology. Commonly, scientific progress in astrophysics is motivated by the empirical success of the "Copernican Principle", that the simplest and most objective analysis of observation leads to progress. A complementary approach tests the prediction of models against observation. In practise, astrophysics has few real theories, and has little control over what we can observe. Compromise is unavoidable. Advances in understanding complex non-linear situations, such as galaxy formation, require that models attempt to isolate key physical properties, rather than trying to reproduce complexity. A specific example is discussed, where substantial progress in fundamental physics could be made with an ambitious approach to modelling: simulating the spectrum of perturbations on small scales.Comment: paper at IAU256, The Galaxy Disk in Cosmological Context, Copenhagen, 2008 eds J. Andersen, J. Bland-Hawthorn & B. Nordstro

Overcoming the barriers of distance: using mobile technology to facilitate moderation and best practice in initial teacher training

This case study describes the development process of a model using readily-available technology to facilitate collaboration, moderation and the dissemination of best practice in initial teacher training in the UK. Students, mentors, tutors and external examiners from a number of educational institutions in a UK, higher education-led Lifelong Learning Sector partnership (LLS) participated. The study explored the extent to which using group video-conferencing software and tablet computing had the potential to model best practice in giving feedback to students, in the setting of targets and in the joint observations of mentors and tutors based in separate institutions. A further area of investigation was the impact of the technology on the observation and moderation of teaching practice by external examiners. The study found that participants could identify a wide range of advantages of using the technology and also some disadvantages. The impact of the study was measured qualitatively via the students’ professional development record (PDR). The challenges involved in undertaking a multi-site study requiring Wi-Fi connectivity and involving participants from several institutions are described. The introduction of key information sets (KISs) related to employability creates an urgent need for HEIs to develop measures which enhance the employment prospects of all students

Music and communication: a study of young children's original melodies

Music and Communication: a study of young\ud children's original melodies".\ud Edward Wilaiam Leggatt, 1979.\ud Earlier research (LEGGATT 1974) suggested that young\ud children can communicate moods through original melodies.\ud The present research examines the discriminating effect on\ud mood communication of the components pitch, rhythm and\ud speed. Age, sex, aural disembedding, perception, personality\ud and ambiguity were considered.\ud The hypotheses adopted were:\ud 1. (i). Junior children can communicate through\ud perceived moods in original melodies.\ud (ii). This communication is made by virtue of one\ud or more components.\ud 2. Communication is dependent on Personality.\ud 3. Communication is dependent on the ability\ud to disembed.\ud 4. Children like ambiguous tunes more than they\ud like unambiguous tunes.\ud Five moods identified as "Angryj comical, dreamy,\ud frightened and sad" were chosen. The experimental method\ud required each composer to produce, in random order on\ud different days, five melodies each evocative of a stated\ud mood. Each tune was recorded on magnetic tape so that\ud listeners could have identical renditions. Each tune was\ud then modified by subtracting successively pitch and rhythm.\ud A third modification was altered speed. Tunes were\ud assessed again for mood categorization; a sample was also\ud assessed for preference of ambiguity or unambiguity.\ud The results after computer and manual analvsis sugyýest:\ud 1. Removal of a musical component alters original\ud mood perception and may cause clustering of mood\ud perceptions.\ud 2. There is a connection between type of musical\ud component perceived and mood.\ud 3. Children's preference for ambiguous or unambiguous\ud tunes is influenced by perceived mood of\ud tune. .1\ud 4. Sex, age, personality and aural disembedding\ud ability do not significantly affect categorizations\ud of original or modified tunes.\ud The PP,, neral im-plications are;\ud In children's own tunes, perceived mood varies as\ud components perceived.\ud 2, The effect of certain components on mood perception\ud may be more readily discernible than others.\ud 3-, It is likely that a consensus exists amongst\ud children regarding the embodiment of tunes.\ud 4. Young children seem to sense bonding characteristics\ud between certain moods embodied in tunes

What happens when grrrls riot? The relationship between feminism and eating pathology in adolescent girls

Over the past fifty years there has been a marked increase in the prevalence of eating disorders (Steiner & Lock, 1998) with women making up the vast majority of sufferers (Mussell, Binford, & Fulkerson, 2000). Growing up female in today\u27s society is a risk factor for eating disorders. Although girls have more opportunities than previously, they are also confronted with powerful cultural messages to please others, through being beautiful, thin, helpful, caring, and self-sacrificing (Weiland Bowling, Schindler Zimmerman, & Carlson Daniels, 2000). As such, teenage girls are more likely than previous generations to struggle with eating disorders, poor self-image, substance abuse, depression, violent relationships, etc. (e.g., Slater, Guthrie, & Boyd, 2001). Theoretical work suggests girls can learn to recognize and reject unhealthy societal messages through exposure to feminist ideas. Although anecdotal evidence points in this direction (Weiland Bowling et al.), empirical research has yet to support this claim. In the current study, 54 adolescent girls involved in a radical feminist oriented group (Riot Grrrls) were compared with 68 girls involved in a group associated with dominant culture messages about female empowerment, i. e., without the cultural critique and activism of radical feminism (Britney Spears fans). The groups were compared on measures of eating pathology, recognition and internalization of socio-cultural messages related to appearance, depression, self-esteem, and self-silencing. Qualitative questions were included to further explore the relationship between feminism and eating pathology. The observed relationships between Radical feminism and eating pathology were inconsistent. Although Riot Grrrls did not have decreased eating pathology, decreased depression, or increased self-esteem compared to Britney Spears fans, they were less likely to internalize cultural messages regarding beauty or to endorse behavioural components of self-silencing. Qualitative data also suggested positive changes for those involved with Riot Grid, including increased acceptance of themselves and their bodies and increased awareness/critiques of cultural messages about beauty. Moreover, elements of feminism, specifically feminist activism were associated with decreased eating pathology (a relationship mediated by internalization of cultural beauty messages). Implications for treatment and prevention programs, as well as directions for future research, are discussed. Source: Dissertation Abstracts International, Volume: 65-07, Section: B, page: 3713. Adviser: Cheryl Thomas. Thesis (Ph.D.)--University of Windsor (Canada), 2004

The theory and practice of jute spinning : being a complete descriptionn of the machines used in the preparation and spinning of jute yarns...

Al final del llibre anuncis industrialsTaques d'òxi

MEAN-VARIANCE OPTIMIZATION AND PORTFOLIO CONSTRUCTION: A SHORT TERM TRADING STRATEGY

Mean-variance optimization, in theory a very powerful and intuitive tool, has failed to provide meaningful solutions in practical settings, and indeed, in theoretical settings in much past research. Whereas inaccurate statistical estimates for inputs provide even more erroneous outputs, the modeling errors determine outputs that are nothing short of extreme. In this study, we employ two different models based on the mean-variance framework, with one portfolio seeking the highest return given a risk target while the other portfolio seeks the lowest risk given a desired level of return. In unconstrained form, our results confirm to be acutely departed from past experience in this subject matter and contrary to the known literature on modeling errors, our portfolios remain solvent. In constrained form, our portfolios outperform the benchmark and market portfolios while maintaining at least some diversification; in unconstrained form, our portfolios provide surprisingly high absolute and risk adjusted returns with betas less than the benchmark and market portfolios

The development and assessment of behavioural markers to support counter-IED training

This article describes the method used to develop and test a checklist of behavioural markers designed to support UK military forces during Counter-Improvised Explosive Device (C-IED) training. IEDs represent a significant threat to UK and allied forces. Effective C-IED procedures and techniques are central to reducing risk to life in this safety critical role. Behavioural markers have been developed to characterise and assess non-technical skills which have been shown to be important in maintaining high performance in other safety critical domains. The aims of this study were two-fold. Firstly to develop a method which could be used to capture and assess operationally relevant behavioural markers for use in C-IED training relating primarily to non-technical skills. Secondly, to test the user acceptance of the behavioural marker checklist during military training activities. Through engagement with military subject matter experts, operationally relevant and observable behaviours seen in C-IED training have been identified and their links to stronger and weaker performance have been established. Using a card-sort technique, the content validity of each of the markers was assessed in addition to their detectability in an operational context. Following this assessment, a selection of the most operationally relevant and detectable behaviours were assimilated into a checklist and this checklist was tested in C-IED training activities. The results of the study show that the method used was effective in generating and assessing the behavioural markers using military subject matter experts. The study also broadly supports the utility and user-acceptance of the use of behavioural markers during training activities. The checklist developed using this methodology will provide those responsible for delivering instruction in C-IED techniques and procedures with a straightforward process for identifying good and poor performance with respect to non-technical skills. In addition it will provide a basis for the provision of focussed feedback to trainees during debrief