1,535 research outputs found

    Worry Domains, Perceived Stress and Social Anxiety Among Tertiary-Level Students in New Zealand

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    Contemporary research into the health concerns of students is sparse, particularly in New Zealand. Overseas literature indicates that students in tertiary education institutions may be at increased risks for physical health problems, stress-related syndromes and emotional dysfunctions. Of particular concern are anxiety disorders as, in addition to their negative impact on quality of life, they are associated with impaired academic performance and poorer educational outcomes. Skilled, educated individuals are a social asset and it is therefore surprising that so little interest has been paid to the ways in which involvement with the tertiary education impacts on student welfare and anxiety levels. As a first step towards redressing the lack of health data for tertiary populations, this thesis investigates aspects of anxiety among students at a New Zealand university. The primary research aims were to establish an estimate of the levels of anxiety experienced by students and to outline the requirements of tertiary study that students perceive to be the most anxiety-inducing. To achieve the former, students (n = 1,082) were invited by e-mail to participate in an online psychometric survey; to explore the latter, discussion groups were arranged wherein students (n = 18) were asked to talk about their anxiety-related experiences. Anxiety has many forms and can be conceptualised in a number of different ways. In recognition of the diverse nature of tertiary study, it was decided that a broad framework would be needed to thoroughly investigate the ways in which it might manifest in tertiary student populations. Thus, a tripartite conceptualisation was constructed, viewing anxiety in cognitive, physiological and interpersonal terms. Specifically, the study assessed worry, stress and social anxiety among tertiary students and invited participants to comment on personal experiences in each of these areas. Comparing study data to norms for student populations in America revealed that New Zealand tertiary students report greater levels of worry, stress and social anxiety than their American counterparts. Within-group comparisons were made as a function of student gender, age, school of study, ethnicity and birth status. Significant differences on at least one survey measure were noted within each of these categories, with the exception of school of study. The possible implications of and explanations for these findings are discussed

    Object-oriented image analysis of cotton cropping areas in the Macintyre Valley using satellite imagery

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    The use of extraction of polygons using software (segmentation) such as eCognition on satellite imagery to produce object based data is becoming more apparent. The technique is impressive on large areas, extracting information which can be processed for whatever purpose, with export options allowing compatibility for use in other software packages. The research is to use Landsat7 imagery with its multispectral bands, applying the object- oriented technology through ENVI 5 software and acquiring an image data set for cotton area estimates and possible infield crop analysis if time permits. The ability to create polyline data sets of specific identities from a remote sensing image has been unachievable efficiently in the past. The rate of computer, computer software technology has enhanced human computer interaction to a level that now makes data extraction of desired properties from a remote sensing image effective and is now a present reality. The intricate options of classification and rule sets within the object-oriented software selection process, is open to the users interpretation and analysis of the required data extracted. The thematic mapper (TM) bands collated from satellite imagery, allow specific features to be isolated from other features by various combinations of TM bands which can highlight the feature or features of interest to be extracted. The following dissertation investigates the desired method used through ENVI 5 software to extract the cotton area data from a cotton property, create the segmentation data sets and test the accuracy, efficiency and effectiveness of this relatively new object-oriented technology

    Death-defying Morphologies: Mass Extinction and Disparity in the Order Harpetida

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    The trilobite order Harpetida has long been easily recognized but poorly understood. This study seeks to better understand the phylogenetic relationships within Harpetida, with a view towards using this group to explore the relationship between extinction intensity and disparity. The harpetid response to the Late Ordovician mass extinction is of particular interest. A discrete morphological character matrix was created from the formal descriptions of harpetids in the published trilobite literature, and refined using first-hand observations of harpetid fossils. The final matrix consists of 76 discrete characters, including 69 cephalic characters, three thoracic characters, and four pygidial characters. This matrix is the first attempt of its kind to characterize the morphology of Harpetida as a whole, rather than focusing on individual harpetid genera. Exemplar species from a broad selection of harpetid genera, along with ptychopariid and redlichiid out groups, were included in the matrix. These taxa were coded from published figures and from direct observation of specimens held in the collections of the Yale Peabody Museum of Natural History. From the matrix, a hypothetical tree of harpetid phylogenetic relationships was generated. The topology of this tree indicates support for harpetid monophyly but throws doubt onto the previous hypotheses of the internal relationships of the group. Disparity analysis of Harpetida reveals a decline in morphological diversity following Late Ordovician, with slow or nonexistent recovery

    Enumeration of idempotents in planar diagram monoids

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    We classify and enumerate the idempotents in several planar diagram monoids: namely, the Motzkin, Jones (a.k.a. Temperley-Lieb) and Kauffman monoids. The classification is in terms of certain vertex- and edge-coloured graphs associated to Motzkin diagrams. The enumeration is necessarily algorithmic in nature, and is based on parameters associated to cycle components of these graphs. We compare our algorithms to existing algorithms for enumerating idempotents in arbitrary (regular *-) semigroups, and give several tables of calculated values.Comment: Majorly revised (new title, new abstract, one additional author), 24 pages, 6 figures, 8 tables, 5 algorithm

    A New and Unifying Approach to Spin Dynamics and Beam Polarization in Storage Rings

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    With this paper we extend our studies [1] on polarized beams by distilling tools from the theory of principal bundles. Four major theorems are presented, one which ties invariant fields with the notion of normal form, one which allows one to compare different invariant fields, and two that relate the existence of invariant fields to the existence of certain invariant sets and relations between them. We then apply the theory to the dynamics of spin-1/2 and spin-1 particles and their density matrices describing statistically the particle-spin content of bunches. Our approach thus unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics. This unifying aspect of our approach relates the examples elegantly and uncovers relations between the various underlying dynamical systems in a transparent way

    An Informal Summary of a New Formalism for Classifying Spin-Orbit Systems Using Tools Distilled from the Theory of Bundles

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    We give an informal summary of ongoing work which uses tools distilled from the theory of fibre bundles to classify and connect invariant fields associated with spin motion in storage rings. We mention four major theorems. One ties invariant fields with the notion of normal form, the second allows comparison of different invariant fields and the two others tie the existence of invariant fields to the existence of certain invariant sets. We explain how the theorems apply to the spin dynamics of spin-1/21/2 and spin-11 particles. Our approach elegantly unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics and suggests an avenue for addressing the question of the existence of the invariant spin field.Comment: Based on a presentation at Spin2014, The 21st International Symposium on Spin Physics, Beijing, China, October 2014. To be published in the International Journal of Modern Physics, Conference Serie

    A detailed and unified treatment of spin-orbit systems using tools distilled from the theory of bundles

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    We return to our study \cite{BEH} of invariant spin fields and spin tunes for polarized beams in storage rings but in contrast to the continuous-time treatment in \cite{BEH}, we now employ a discrete-time formalism, beginning with the Poincareˊ\rm{Poincar\acute{e}} maps of the continuous time formalism. We then substantially extend our toolset and generalize the notions of invariant spin field and invariant frame field. We revisit some old theorems and prove several theorems believed to be new. In particular we study two transformation rules, one of them known and the other new, where the former turns out to be an SO(3)SO(3)-gauge transformation rule. We then apply the theory to the dynamics of spin-1/21/2 and spin-11 particle bunches and their density matrix functions, describing semiclassically the particle-spin content of bunches. Our approach thus unifies the spin-vector dynamics from the T-BMT equation with the spin-tensor dynamics and other dynamics. This unifying aspect of our approach relates the examples elegantly and uncovers relations between the various underlying dynamical systems in a transparent way. As in \cite{BEH}, the particle motion is integrable but we now allow for nonlinear particle motion on each torus. Since this work is inspired by notions from the theory of bundles, we also provide insight into the underlying bundle-theoretic aspects of the well-established concepts of invariant spin field, spin tune and invariant frame field. Since we neglect, as is usual, the Stern-Gerlach force, the underlying principal bundle is of product formso that we can present the theory in a fashion which does not use bundle theory. Nevertheless we occasionally mention the bundle-theoretic meaningof our concepts and we also mention the similarities with the geometrical approach to Yang-Mills Theory

    A Taxonomic Revision of Eastern North Pacific Softnose Skates (Arhynchobatidae: Bathyraja Ishiyama)

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    Softnose skates (Rajiformes: Arhynchobatidae: Bathyraja Ishiyama) are the most diverse genus of skates, with 54 described species, and are readily distinguishable from their congeners by their relatively uncalcified and flexible rostral cartilages. Six species of Bathyraja are considered valid in the eastern North Pacific, including: deepsea skate, B. abyssicola, Aleutian skate, B. aleutica, sandpaper skate, B. kincaidii, fine-spined skate, B. microtrachys, Pacific white skate, B. spinosissima, and roughtail skate, B. trachura. As with other skate genera, the eastern North Pacific Bathyraja lacks a well-supported phylogeny, which leads to issues with setting catch limits and creating management plans. This study identifies and formally describes the softnose skates species in the eastern North Pacific based on morphometric and meristic measurements and includes an Alaskan species, Bering skate, B. interrupta due to its close morphological relationship to B. kincaidii. Multivariate tests determined that significant differences existed between the study species. Parsimonious phylogenetic trees showed that B kincaidii represents the basal condition, with B. abyssicola and B. aleutica being the most derived species in the study. The synonymized species B. interrupta and B. kincaidii were shown to be separate, as were the synonymized species B. microtrachys and B. trachura. An improved Bathyraja phylogeny will hopefully assist fisheries managers in developing conservation policies and easing the impacts of deepsea fishing expansion
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