Learning by building digital libraries

The implications of using digital library software in educational contexts, for both students and software developers, are discussed using two case studies of students building digital libraries

A taxonomic revision of Capnophyllum (Apiaceae: Apioideae)

AbstractThe Cape endemic genus Capnophyllum Gaertn. is revised. As a result of valuable recent collections and extensive fieldwork, this hitherto neglected genus was found to comprise four annual species, two of which are newly described, namely C. lutzeyeri Magee and B.-E.van Wyk, and C. macrocarpum Magee and B.-E.van Wyk. The four species are distinguished from one another by their fruit morphology (relative length of the styles, the shape and position of the stylopodium, fruit size, surface sculpturing, and the presence or absence of a sterile apical portion) and fruit anatomy (marginal wings slightly or prominently involute and secondary ribs present or absent). A comprehensive key to the species, their complete nomenclature and typification, together with complete descriptions and known geographical distributions for all the species are presented and illustrated

Thermodynamic and structural properties of zinc/copper alloys

The thesis, entitled as above, is concerned with the measurement of thermodynamic properties of zinc copper alloys in the liquid and solid states, and with the interpretation of these in terms of alloy structure. A conventional dew-point technique was used to determine, initially, the vapour pressure of the zinc component at a number of temperatures and, from these values, partial and integral thermodynamic functions were calculated. For evaluation of the vapour pressures, the equations of Kubaschewski and Evans, relating the vapour pressure of pure zinc, in solid and liquid otates,to temperature were used as a basis. The results of other workers were recalculated, wherever possible, to the same basis for comparison. In general, the present results show fair agreement with previous work but with certain differences. For liquid alloys, for instance, a change from negative to positive deviation +0. from ideality is shown by the thermodynamic activity of the zinc as high zinc contents are approached. Previously, the results of other workers have indicated negative deviation over the whole compositional range. Also, characteristic minima and maxima were obtained in the curves when Deltas-x zn values from the present work on liquid and solid alloys were plotted against composition. One of these minima, viz. that occurring at 0.43 NZn in the solid alloys, is considered difficult to explain and probably spurious. Otherwise, the minima occur at compositions corresponding approximately to the centre of the beta and r-phase fields and are associated with the critical electron/atom ratios (1.48 and 1.615 respectively) required, by electron theory for the formation of the appropriate electron compounds. The peak positive value (i.e. highest maximum) in the DeltaS-x zn curve for liquid alloys, which occurs at 0.68 Nzn, has analogies in at least two other binary systems, viz. Zn/Sb and Cd/Sb. This positive value of excess entropy is considered to be associated with an increased vibrational contribution to entropy, and linked with the previously reported defect structure of the delta-phase. Quantitative application of quasi-chemical theory to the partial and integral thermodynamic functions was attempted but, after comparison with other systems, reasons are advanced for the limited applicability. However, qualitative application, particularly when integral properties are considered, is possible. The partial thermodynamic functions of the second component, i.e. copper, were calculated from the Gibbs-Duhem relationship, and thus integral properties obtained. For the liquid alloys, both of the partial and the integral functions are compared and the conclusion drawn that, in certain compositional regions there is build up of "excess" enthalpy (stored probably as vibrational energy) which is released again to allow the "minimum" value to he attained at fixed compositions. Two of these fixed compositions co-incide approximately with the critical electron/atom ratios necessary, according to electron theory, for the formation of the beta and r-phases in solid alloys, but it is postulated that the true "critical" compositions are those corresponding to the maximum build-up of excess enthalpy. In addition, the variation of the partial properties in the region of those critical compositions suggests that the release of the excess enthalpy is accompanied by a redistribution of the vibrational energy between the two components of the solution. Because of the close approximation of the compositions, at which the minimal values occur, to the centres of the solid beta, -r and -phase fields, a fourth minimum, corresponding to the unexplored delta-phase field region is predicted. Also, the existence of these minima, in plots referring to liquid alloys, is taken as an indication of the extent to which "solid" structures persist above liquidus temperatures. The above postulations and the link with electron theory are less clearly applicable to the solid alloys, but sufficient similarity exists to suggest that complete analogy may be established by further study

The Physical Health of Caregivers of Children With Life-Limiting Conditions: A Systematic Review

CONTEXT: Parental caregiving for a child with a life-limiting condition (LLC) is complex physical and mental work. The impact of this caregiving on parents' physical health is unknown. OBJECTIVES: (1) To review existing evidence on the physical health of parents caring for a child with a LLC and (2) to determine how physical health of parents is measured. DATA SOURCES: Medline, Embase, PsycINFO, and Cumulative Index of Nursing and Allied Health Literature were searched. STUDY SELECTION: Peer-reviewed articles were included if they reported primary data on the physical health of a caregiver of a child with a LLC. Studies were excluded if they described only the caregiver's mental health or if the caregivers were bereaved at the time of data collection. DATA EXTRACTION: Of 69 335 unique citations, 81 studies were included in the review. RESULTS: Caregiver health was negatively impacted in 84% of studies. Pain and sleep disturbance were the most common problems. Ways of measuring the physical health of caregiver varied widely. We found an absence of in-depth explorations of the social and economic contexts, which could potentially mitigate the impact of caregiving. Furthermore, we find health interventions tailored to this group remain largely unexplored. LIMITATIONS: Studies were heterogenous in methodology, making comparisons of results across studies difficult. CONCLUSIONS: These findings support the need for improving access to interventions aimed at improving physical health in this population. The rate of health-seeking behaviors, preventive health care access and screening for health conditions is understudied and represent important directions for further research

Long-term daily administration of aprepitant for the management of intractable nausea and vomiting in children with life-limiting conditions: a case series.

BACKGROUND: Nausea and vomiting is a common symptom in children through their end of life journey. Aprepitant, a NK-1 antagonist, has become a potent weapon in the fight against chemo-induced nausea and vomiting. However, its use in palliative care for refractory nausea and vomiting has been limited due to limited experience or evidence of continuous use. Emerging evidence suggests that continuous use is not only safe, but also effective in patients with nausea and vomiting refractory to multiple lines of anti-emetic therapy. METHODS: We conducted a single centre retrospective chart review of children receiving care from a specialist palliative care team who were given continuous daily aprepitant for nausea and vomiting and were unresponsive to at least 2 prior lines of anti-emetic therapy. Parental reports of the impact of nausea on mobility and feeding were used as proxy efficacy markers. Duration of effect and toxicity was also evaluated. RESULTS: 10 children (8 with cancer as a primary diagnosis and 2 with non-cancer diagnoses) received continuous aprepitant and all showed resolution of nausea and vomiting and an increased ability to mobilise and tolerate feeds. No adverse events noted. CONCLUSION: Our review suggests a role for aprepitant in management of refractory nausea and vomiting, demonstrating safety and efficacy. This case series is the first report of aprepitant use in this manner in the paediatric palliative care setting

Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)

This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process

Physics Performance Report for PANDA Strong Interaction Studies with Antiprotons

To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be build. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the-art internal target detector at the HESR at FAIR allowing the detection and identifcation of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected