Preparation of theophylline inhalable microcomposite particles by wet milling and spray drying: the influence of mannitol as a co-milling agent

Inhalable theophylline particles with various amounts of mannitol were prepared by combining wet milling in isopropanol followed by spray drying. The effect of mannitol as a co-milling agent on the micromeritic properties, solid state and aerosol performance of the engineered particles was investigated. Crystal morphology modelling and geometric lattice matching calculations were employed to gain insight into the intermolecular interaction that may influence the mechanical properties of theophylline and mannitol. The addition of mannitol facilitated the size reduction of the needle-like crystals of theophylline and also their assembly in microcomposites by forming a porous structure of mannitol nanocrystals wherein theophylline particles are embedded. The microcomposites were found to be in the same crystalline state as the starting material(s) ensuring their long-term physical stability on storage. Incorporation of mannitol resulted in microcomposite particles with smaller size, more spherical shape and increased porosity. The aerosol performance of the microcomposites was markedly enhanced compared to the spray-dried suspension of theophylline wet milled without mannitol. Overall, wet co-milling with mannitol in an organic solvent followed by spray drying may be used as a formulation approach for producing respirable particles of water-soluble drugs or drugs that are prone to crystal transformation in an aqueous environment (i.e. formation of hydrates)

High School Media Too: A School Day in the Lives of Fifteen Teenagers

An observational study of media consumption and exposure throughout the school day of fifteen middle- and high-school students. The study measures exposure in ten second increments in all locations from home and car through school and others and details incidence and duration os media use. Results also details incidence of Concurrent Media Exposure (multi-tasking)

Impairments to Thermoregulation in the Elderly During Heat Exposure Events

Heat waves represent a public health risk to elderly people, and typically result in an increased rate of hospital admissions and deaths. Studies of thermoregulation in this cohort have generally focused on single elements such as sweating capacity. Sweating capacity and skin blood flow reduce with age, reducing ability to dissipate heat. Perception of effort during heat exposure is emerging as an area that needs further investigation as the elderly appear to lack the ability to adequately perceive increased physiological strain during heat exposure. The role of the gut and endotoxemia in heat stress has received attention in young adults, while the elderly population has been neglected. This shortcoming offers another potential avenue for identifying effective integrated health interventions to reduce heat illnesses. Increasing numbers of elderly individuals in populations worldwide are likely to increase the incidence of heat wave-induced deaths if adequate interventions are not developed, evaluated, and implemented. In this narrative-style review we identify and discuss health-related interventions for reducing the impact of heat illnesses in the elderly

Struggling and juggling: a comparison of assessment loads in research and teaching-intensive universities

In spite of the rising tide of metrics in UK higher education, there has been scant attention paid to assessment loads, when evidence demonstrates that heavy demands lead to surface learning. Our study seeks to redress the situation by defining assessment loads and comparing them across research-and teaching intensive universities. We clarify the concept of ‘assessment load’ in response to findings about high volumes of summative assessment on modular degrees. We define assessment load across whole undergraduate degrees, according to four measures: the volume of summative assessment; volume of formative assessment; proportion of examinations to coursework; number of different varieties of assessment. All four factors contribute to the weight of an assessment load, and influence students’ approaches to learning. Our research compares programme assessment data from 73 programmes in 14 UK universities, across two institutional categories. Research-intensives have higher summative assessment loads and a greater proportion of examinations; teaching-intensives have higher varieties of assessment. Formative assessment does not differ significantly across both university groups. These findings pose particular challenges for students in different parts of the sector. Our study questions the wisdom that ‘more’ is always better, proposing that lighter assessment loads may make room for ‘slow’ and deep learning

The Planetary Nebulae Spectrograph: the green light for Galaxy Kinematics

Planetary nebulae are now well established as probes of galaxy dynamics and as standard candles in distance determinations. Motivated by the need to improve the efficiency of planetary nebulae searches and the speed with which their radial velocities are determined, a dedicated instrument - the Planetary Nebulae Spectrograph or PN.S - has been designed and commissioned at the 4.2m William Herschel Telescope. The high optical efficiency of the spectrograph results in the detection of typically ~ 150 PN in galaxies at the distance of the Virgo cluster in one night of observations. In the same observation the radial velocities are obtained with an accuracy of ~ 20 km/sComment: Accepted by PASP, to appear November 2002; the figures have been degraded for archival purpose

Time-variation of Jupiter's internal magnetic field consistent with zonal wind advection

Determination of the time dependency (secular variation) of a planet’s magnetic field provides a window into understanding the dynamo responsible for generating its field. However, of the six Solar System planets with active dynamos, secular variation has been firmly established only for Earth. Here, we compare magnetic field observations of Jupiter from the Pioneer 10 and 11, Voyager 1 and Ulysses spacecraft (acquired 1973–1992) with a new Juno reference model (JRM09). We find a consistent, systematic change in Jupiter’s field over this 45-year time span, which cannot be explained by changes in the magnetospheric field or by changing the assumed rotation rate of Jupiter. Through a simplified forward model, we find that the inferred change in the field is consistent with advection of the field by Jupiter’s zonal winds, projected down to 93–95% of Jupiter’s radius (where the electrical conductivity of the hydrogen envelope becomes sufficient to advect the field). This result demonstrates that zonal wind interactions with Jupiter’s magnetic field are important and lends independent support to atmospheric and gravitational-field determinations of the profile of Jupiter’s deep winds

Trace Metal and Chlorinated Hydrocarbon Concentrations in Shellfish and Fin-Fish from Irish Waters - 1996

In accordance with the monitoring requirements of the 1979 Council Directive 79/923/EC on the quality of shellfish waters, water and shellfish samples were collected from 22 major shellfish growing areas and analysed for physicochemical parameters, trace metal levels and chlorinated hydrocarbon concentrations. Fin-fish were also collected from five Irish fishing ports and analysed for total mercury content in compliance with the European Commission's Decision of 19 May 1993 on mercury in fisheries products. Selected samples of fin-fish were also analysed for trace metal and chlorinated hydrocarbon concentration. As there are no generally accepted European standards for the concentration of these contaminants in shellfish or fin-fish, the levels were compared with the available standards and guidance values compiled by the Oslo and Paris Commission (OSPAR) countries for human consumption. As in previous years, the water quality from shellfish growing areas was good and conformed to the guidelines and requirements of the Directive. Petroleum hydrocarbons were not observed in any of the shellfish waters or as deposits on the shellfish. Chlorinated hydrocarbon levels were very low, evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. Trace metal levels were consistently low with the exception of lead in mussel tissue from Wexford Harbour, which was elevated, and cadmium in oyster tissue, which was slightly elevated in some samples but did not exceed the Dutch human consumption tolerance value of 1.0mg/kg. The concentration of mercury in fin-fish selected from catches at Irish fishing ports ranged from 0.02 to 0.27µg/g wet weight. These levels were well within the maximum limits set down in the EC Decision for mercury in fisheries products. Chlorinated hydrocarbon and trace metal levels were also very low in fish tissue. This survey confirms previous studies that show Irish fishery products are effectively free from trace metal and chlorinated hydrocarbon contamination

Let’s stop the pretence of consistent marking: exploring the multiple limitations of assessment criteria

Unreliability in marking is well documented yet we lack studies that have investigated assessors’ detailed use of assessment criteria. This project used a form of Kelly’s Repertory Grid method to examine the characteristics that 24 experienced, UK assessors notice in distinguishing between students’ performance in four contrasting subject disciplines: that is their implicit assessment criteria. Variation in the choice, ranking and scoring of criteria was evident. Inspection of the individual construct scores in a sub-sample of academic historians revealed five factors in the use of criteria that contribute to marking inconsistency. The results imply that whilst more effective and social marking processes that encourage sharing of standards in institutions and disciplinary communities may help align standards, assessment decisions at this level are so complex, intuitive and tacit that variability is inevitable. It concludes that universities should be more honest with themselves and with students and actively help students to understand that application of assessment criteria is a complex judgement and there is rarely an incontestable interpretation of their meaning

Breaking boundaries: a model of student-led knowledge exchange for higher education

Knowledge exchange (KE) is increasingly important in higher education internationally, yet relatively little attention has been paid to it as a pedagogic opportunity for students. This paper draws on 26 interviews with stakeholders within and outside HE to develop a model of student-led knowledge exchange as a guide for learning through KE. The model includes the following elements: Preconditions, Prior Knowledge, Planning and Place, Pedagogic Context and Product, and offers an analysis of different forms of KE which occur between individuals in a learning triad consisting of student, facilitator and external participant. The research foregrounds a social view of learning where valid knowledge comes from diverse participants in the exchange, including students themselves. Students act as a catalyst for multi-directional KE–a finding which challenges the implied hierarchies evident in much of the literature on this topic. The model is offered as a starting point for developing a pedagogy of KE in higher education