Dynamic phenomena arising from an extended Core Group model

In order to obtain a reasonably accurate model for the spread of a particular infectious disease through a population, it may be necessary for this model to possess some degree of structural complexity. Many such models have, in recent years, been found to exhibit a phenomenon known as backward bifurcation, which generally implies the existence of two subcritical endemic equilibria. It is often possible to refine these models yet further, and we investigate here the influence such a refinement may have on the dynamic behaviour of a system in the region of the parameter space near R0 = 1. We consider a natural extension to a so-called core group model for the spread of a sexually transmitted disease, arguing that this may in fact give rise to a more realistic model. From the deterministic viewpoint we study the possible shapes of the resulting bifurcation diagrams and the associated stability patterns. Stochastic versions of both the original and the extended models are also developed so that the probability of extinction and time to extinction may be examined, allowing us to gain further insights into the complex system dynamics near R0 = 1. A number of interesting phenomena are observed, for which heuristic explanations are provided

White-headed Vultures Trigonoceps occipitalis show visual field characteristics of hunting raptors

The visual fields of Aegypiinae vultures have been shown to be adapted primarily to meet two key perceptual challenges of their obligate carrion-feeding behaviour: scanning the ground and preventing the sun’s image falling upon the retina. However, field observations have shown that foraging White-headed Vultures (Trigonoceps occipitalis) are not exclusively carrion-feeders; they are also facultative predators of live prey. Such feeding is likely to present perceptual challenges that are additional to those posed by carrion-feeding. Binocularity is the key component of all visual fields and in birds it is thought to function primarily in the accurate placement and time of contact of the talons and bill, especially in the location and seizure of food items. We determined visual fields in White-headed Vultures and two species of carrion-eating Gyps vultures, and show that the visual field of White-headed Vultures have more similarities with those of predatory raptors (e.g. Accipitrid hawks), compared with the taxonomically more closely related Gyps vultures. We found that maximum binocular field width in White-headed vultures (30°) is significantly wider than Gyps vultures (20°). The broader binocular fields in White-headed Vultures probably facilitate accurate placement and timing of the talons when capturing evasive live prey

The evolution of Internet addiction: A global perspective

Kimberly Young’s early work on Internet addiction (IA)has been pioneering and her early writings on the topic inspired many others to carry out research in the area. Young's (2015) recent paper on the 'evolution of Internet addiction' featured very little European research, and did not consider the main international evidence that has contributed to our current knowledge about the conceptualization, epidemiology, etiology, and course of Internet-related disorders. This short commentary paper elaborates on important literature omitted by Young that the present authors believe may be of use to researchers. We also address statements made in Young’s (2015) commentary that are incorrect (and therefore misleading) and not systematically substantiated by empirical evidence

Arnold Trowell - Violoncellist, Composer and Pedagogue

This thesis is the first study of Arnold Trowell, cellist, composer, conductor and teacher. It is primarily concerned with the cellist’s contribution to pedagogy and composition as informed by biographical detail. The latter begins with an initial examination of the life of his father, Thomas. Starting in the 1880s with Thomas’ arrival in Wellington, New Zealand the family background is discussed in terms of the musical climate of that city. Arnold’s creative and professional life in Great Britain and Europe provides the main body of the subsequent chapters of this study. Arnold Trowell was born in Wellington in 1887. He was an eminent and successful musician in England from 1907 until his death in 1966. Virtually forgotten since, he wrote a large number of pedagogical compositions that are still played by young cellists, as well as numerous substantial works for a variety of chamber music ensembles and symphony orchestra. After studying cello and composition in Frankfurt and Brussels from 1903, Trowell moved to England where, in 1906, he began teaching, performing and publishing. His compositions include seven concertos, three sonatas, four symphonic poems and numerous pieces for cello and piano. Trowell was Professor of Cello at the Guildhall School of Music and the Royal College of Music and a cellist who was described by Edmund van der Straeten as “in a line with the greatest virtuosos of the present time.” He gave hundreds of concerts throughout Great Britain and Northern Ireland and broadcast frequently with the BBC. The thesis addresses three research questions: What was the context and nature of his career as a virtuoso cellist? Was Trowell’s main contribution to music in the pedagogical field? If so, was it primarily for composition or his teaching? Three major sections relate to Trowell’s career as performer, teacher and composer. A chronological framework is adopted for Part One: Life of Arnold Trowell that focuses on the early years of the cellist’s life. Part Two begins with a survey of the development of cello technique in the early twentieth century and ends with a detailed analysis of Trowell’s solo and accompanied cello works. Musical illustrations from Trowell’s scores and the similar works by other composers are provided. Part Three addresses the chamber and orchestral music. Appendices include a list of Trowell’s complete works, further information on contemporaneous cellists, etudes and bow techniques of the early twentieth century, a detailed and select list of Trowell’s students, as well as his writings on technique and pedagogy. A complete edition of the 24 Etudes Technology of Violoncello Book IV and a compact disc recording of works by Arnold Trowell are included. The conclusion is that Trowell’s major contribution to music was in the area of cello pedagogy, in particular, the composition of teaching etudes and miniatures

Benzodiazepine dependence studies in animals: An overview

A selective review of benzodiazepine dependence studies in animals is presented, emphasizing areas of drug self-injection, drug discrimination, and physiological dependence. Benzodiazepines as a class, as well as long-acting barbiturates, appear to maintain drug self-injection behavior less well than ultrashort-acting barbiturates. The duration of action as well as the rapidity of onset of these drugs may be important determinants of their reinforcing efficacy. Drug discrimination procedures may allow evaluation of the relative rapidity at onset and duration of action of these drugs to evaluate this and related hypotheses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50212/1/430010712_ftp.pd

Automatic river quality monitoring

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.Automatic river quality monitoring (ARQM) is potentially an important tool in water quality management for the National Rivers Authority (NRA) and similar organisations worldwide. The information produced by ARQM systems must be used in the most effective way and fully integrated with the manual monitoring effort. The status and development of ARQM systems in the freshwater and estuarine River Thames catchment are discussed and a practical appraisal of the design, operation and maintenance requirements given. Data capture, verification and presentation methods are developed and the use of ARQM data for real time management and subsequent analysis is advocated. Examples of data from the freshwater ARQM system are given which emphasise the variability of freshwater quality and the need for a comprehensive understanding of the behaviour of rivers before management decisions are made. The use of ARQM data for assessing the compliance of rivers with River Quality Objectives is examined. With respect to the tidal Thames, data processing methods to correct for the tidal movement of the waterbody are developed. ARQM data are used to highlight the principal factors affecting the water quality of the tidal Thames. The importance of the use of ARQM information in the effective management of the tidal Thames is discussed and operational examples demonstrate how it may be utilised as a basis for management decisions. The application of ARQM to the sub-tropical environment of the River Ganges, India, is investigated. An ARQM system has been designed and prototypes are operational. Extensive site surveys were carried out and the water quality status of the Ganges is discussed. Recommendations for the improvement and future development of ARQM systems are made. The use of ARQM information and its potential for improving the management of rivers is discussed.National Rivers Authorit

Dispersion of seabirds at sea in the Southern Ocean

Bibliography: pages 57-66.The feasibility of obtaining information on the dispersion of seabirds at sea precise enough to reflect changes in their prey was investigated. A standardized technique for counting birds from a moving ship, designed to limit biases due to birds circling, following and/or deviating towards/from the ship, is suggested. An interspecific comparison of 31 seabird species was made to determine which species yielded the most accurate censuses. Although many species are attracted towards the ship, only the Wandering Albatross Diomedea exulans follows for long periods. Counts from a stationary ship are shown to be unsuitable for abundance and biomass estimates, because of the accumulation of birds around the ship. The avifauna at sea is described in terms of species richness, diversity, abundance, biomass and trophic groups of 42 pelagic species (penguins excluded). Birds eating plankton and cephalopods are the most abundant; few birds eat fish. Plankton- and cephalopod-eaters occur most abundantly in the south and north of the study area, respectively. An association between their distribution and the availability of their principal prey is proposed. The effect of five abiotic features on seabird distribution was investigated. Although significant preference for specific ranges of features is demonstrated, linear correlations are weak (maximum correlation coefficient (r = 0.325). Abiotic features associated with the distribution of the Snow Petrel Pagodroma nivea and the Antarctic Petrel Thalassoica antarctica were investigated in greater detail. Statistical relationships between the species' occurrence and measured oceanographic and meteorological features are inconclusive. Associations with prey are discounted, because of the birds' apparently unspecialized diet and opportunistic feeding. The two species occur in or near sea-ice. Their restriction to this area and the concomitant absence of other procellariiform species appears to be consequent on the species' flight characteristics. The merits of using seabirds at sea as biological indicators of prey resources are discussed

Playing with fire: Islamism and politics in Bangladesh

The news yesterday that an Islamic militant group in Bangladesh had published a ‘global hitlist’ of atheist bloggers follows a series of brutal activist murders over the last year and a half. Martin Griffiths and Mubashar Hasan argue that increasing influence of Islamist groups can be linked to successive governments in Bangladesh moving away from the promise of secularism that underpinned the creation of the country

Power and representation: A postcolonial reading of global partnerships and teacher development through North-South study visits.

publication-status: Acceptedtypes: ArticleThis paper critically analyses the neoliberal discourse informing global education policy and practice. We use postcolonial theory to deconstruct the contexts for global educational partnerships, highlighting how issues of power and representation are central to their development and the learning that takes place within them. Teacher development through North-South study visits is one way of challenging teachers’ worldviews, but these are not always effective. We argue that study visit courses, where learning is facilitated by differently knowledgeable others, have the potential to be more effective, but only if the courses are underpinned by postcolonial theory and informed by socio-cultural pedagogy

Species Composition, Diversity and Distribution of Vascular Epiphytes in the Kihansi Gorge Forest, Tanzania

This study aimed to assess the species composition, diversity and distribution of vascular epiphytes in the Kihansi Gorge Forest. Epiphytes sampling was conducted in twenty sampling plots established in the strip of riverine forest within the Kihansi Gorge. All vascular epiphytes growing on trees (phorophytes) rooted in the plots were sampled using ground-based technique as the method of access to the tree canopies.  A total of 476 epiphyte individuals belonging to 20 species and 10 families were recorded in the study area. Among the twenty species recorded, Drynaria laurentii was the most abundant and most widely distributed in the study area.  The epiphyte individuals were unevenly distributed within the twenty species. Epiphyte species richness and diversity was highest in KM transect and lowest in KS transect, while the epiphyte abundance was highest in KH transect. Along the phorophytes, 62% of the vascular epiphyte individuals occupied a zone upper than ten metres.  In general, the Kihansi Gorge Forest is a home to twenty epiphyte species, dominated by ferns and orchids. The highest diversity in the study area was found in KM transect which was located at mid-elevation. On the phorophytes, higher abundance of epiphytes was found in the upper zone.Keywords: Kihansi Gorge; Vascular epiphyte; Canopy; Diversity; Phorophyt