Disposition of theophylline and aminophylline in man

Imperial Users onl

The characteristics of a national register of people with multiple sclerosis (MS): A comparison between the ARMS (Action for Research into Multiple Sclerosis) register and 10 British MS populations

This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @Problems with case ascertainment in epidemiological research on multiple sclerosis (MS) make it necessary to use indirect sources. However, there is a lack of information about the characteristics of cases drawn from different sources and thus little basis on which sampling frames for large scale surveys may be constructed. The characteristics of a population drawn from the membership of Action for Research into Multiple Sclerosis (ARMS) were compared with those of 10 other British MS populations reported between 1980 and 1987. Demographic variables examined were geographical location, nationality, ethnicity, sex ratio and age. Diagnostic status, age at diagnosis and duration since diagnosis were considered together with data on the comparative populations based on date of onset. On all the variables investigated the ARMS population fell close to or within the range shown by the comparative populations. The relative youth of the ARMS population and its bias towards a high proportion of females were differences in keeping with existing knowledge about the membership of mutual support organisations. A population drawn from such an organisation may usefully complement other MS research populations provided that the likely biases in each are understood.The study was funded by Action for Research into Multiple Sclerosis

Perceptions of the singing voice.

This study takes a multi-disciplinary approach to examine the layers of meaning given to vocal timbre when singers talk about their voices. Three different approaches are taken for the Phase I exploration; semi-structured interviews with solo, choral, amateur and professional singers, questionnaires for school students and singing teachers featuring recordings of different vocal genres and diaries of the vocal experiences of professional singers. Three aspects of vocal identity are discussed: reflection and construction of the voice and expression using the voice. A taxonomy of vocal development is created. The classification of metaphors describing vocal timbre provides a framework for discussion leading to Phase II. The concepts of space and movement are identified within the diary data of the professional singers. Phase II focuses on data collected during the preparation of a specific recording task. The sample consists of 22 amateur solo singers, aged between 11 and 65 years from a variety of backgrounds and musical experience. Diary and interview discourse are classified and the importance of acoustic responses in the narratives of the more experienced singers is noted. The reactions of singers to hearing the recording made of them singing highlight the differences between internally and externally perceived vocal timbres. Features indicate a tendency for the internally perceived timbre to be lower, richer and more mature than the sound heard externally. The different use of metaphor illustrates the levels of vocal perception taking place. The prominence of space and metaphor concepts is found in the discourse of more experienced performers in both Phase I and Phase II. This study has implications for singers and teachers of singing. It offers a framework of metaphorical descriptions to facilitate the shared understanding of terms referring to vocal timbres and it suggests that the aural mismatch of sound and the role of auditory memory are important subjects for further investigation

Reactive oxygen species initiate luminal but not basal cell death in cultured human mammary alveolar structures: a potential regulator of involution

Post-lactational involution of the mammary gland is initiated within days of weaning. Clearing of cells occurs by apoptosis of the milk-secreting luminal cells in the alveoli and through stromal tissue remodeling to return the gland almost completely to its pre-pregnant state. The pathways that specifically target involution of the luminal cells in the alveoli but not the basal and ductal cells are poorly understood. In this study we show in cultured human mammary alveolar structures that the involution process is initiated by fresh media withdrawal, and is characterized by cellular oxidative stress, expression of activated macrophage marker CD68 and finally complete clearing of the luminal but not basal epithelial layer. This process can be simulated by ectopic addition of reactive oxygen species (ROS) in cultures without media withdrawal. Cells isolated from post-involution alveoli were enriched for the CD49f+ mammary stem cell (MaSC) phenotype and were able to reproduce a complete alveolar structure in subcultures without any significant loss in viability. We propose that the ROS produced by accumulated milk breakdown post-weaning may be the mechanism underlying the selective involution of secretory alveolar luminal cells, and that our culture model represents an useful means to investigate this and other mechanisms further

The TOMCAT global chemical transport model v1.6: description of chemical mechanism and model evaluation

This paper documents the tropospheric chemical mechanism scheme used in the TOMCAT 3-D chemical transport model. The current scheme includes a more detailed representation of hydrocarbon chemistry than previously included in the model, with the inclusion of the emission and oxidation of ethene, propene, butane, toluene and monoterpenes. The model is evaluated against a range of surface, balloon, aircraft and satellite measurements. The model is generally able to capture the main spatial and seasonal features of high and low concentrations of carbon monoxide (CO), ozone (O3), volatile organic compounds (VOCs) and reactive nitrogen. However, model biases are found in some species, some of which are common to chemistry models and some that are specific to TOMCAT and warrant further investigation. The most notable of these biases are (1) a negative bias in Northern Hemisphere (NH) winter and spring CO and a positive bias in Southern Hemisphere (SH) CO throughout the year, (2) a positive bias in NH O3 in summer and a negative bias at high latitudes during SH winter and (3) a negative bias in NH winter C2 and C3 alkanes and alkenes. TOMCAT global mean tropospheric hydroxyl radical (OH) concentrations are higher than estimates inferred from observations of methyl chloroform but similar to, or lower than, multi-model mean concentrations reported in recent model intercomparison studies. TOMCAT shows peak OH concentrations in the tropical lower troposphere, unlike other models which show peak concentrations in the tropical upper troposphere. This is likely to affect the lifetime and transport of important trace gases and warrants further investigation

Fostering the next generation of reviewers in New Zealand ecology

Conservation Biolog