A case study of transport of tropical marine boundary layer and lower tropospheric air masses to the northern midlatitude upper troposphere

Low-ozone (<20 ppbv) air masses were observed in the upper troposphere in northern midlatitudes over the eastern United States and the North Atlantic Ocean on several occasions in October 1997 during the NASA Subsonic Assessment, Ozone and Nitrogen Oxide Experiment (SONEX) mission. Three cases of low-ozone air masses were shown to have originated in the tropical Pacific marine boundary layer or lower troposphere and advected poleward along a warm conveyor belt during a synoptic-scale disturbance. The tropopause was elevated in the region with the low-ozone air mass. Stratospheric intrusions accompanied the disturbances. On the basis of storm track and stratospheric intrusion climatologies, such events appear to be more frequent from September through March than the rest of the year. Copyright 2000 by the American Geophysical Union

Paediatric chronic suppurative otitis media in the Free State Province: Clinical and audiological features

Background. Chronic suppurative otitis media (CSOM) is a chronic infection of the middle ear cleft. In sub-Saharan Africa >50% of cases occur in children <10 years of age.Objectives. To describe the otological, audiological and bacteriological findings in children with CSOM.Methods. We conducted a prospective study at the Ear, Nose and Throat (ENT) Clinic at Universitas Academic Hospital between August 2009 and December 2010. We included all children with CSOM over this period. Patients underwent ENT and paediatric examination, and were tested for HIV. Pus swabs were taken after an ear toilet for routine microbiology, fungal and Mycobacterium tuberculosis culture. We performed audiological testing after the otorrhoea had resolved.Results. Eighty-six children (113 ears) were included, with a median age of 4.6 years (range 1 - 12 years). The mean duration of otorrhoea was 161.7 weeks (range 4 - 572 weeks). Nine patients (10.5%) presented with coalescent mastoiditis and/or intracranial complications of CSOM. Of the 153 organisms identified, Gram-negative bacteria were present in 93 (82.3%) ears, with 94.8% of these being sensitive to quinolones. Only 1 case of tuberculous otitis media was identified. HIV infection was present in 54.6% of patients tested. There was a hearing loss in 44 (66.7%) of the tested affected ears.Conclusions. There was a long delay between the onset of symptoms and accessing ENT services. Most cases of CSOM were due to quinolone-sensitive Gram-negative aerobes. There was a high prevalence of cholesteatoma, hearing loss and other complications in children in this study

Mapping the Spread of Malaria Drug Resistance

Tim Anderson discusses a new study of molecular variation in alleles at the dihydropteroate synthase locus, which underlies resistance to sulfadoxine, in over 5,000 parasites from 50 locations

‘Don’t just travel’: thinking poetically on the way to professional knowledge

This paper describes how the medium of ‘found poetry’ is incorporated into a doctoral programme for nurses, educators and allied health and social care professionals at the start of their various doctoral journeys. It advocates a narrative practice approach to issues of researcher identity and reflexivity. ‘Finding’ the poems begins with the creation of collages as representational anchors for students to talk about themselves, their professional practice, their hopes and expectations of the doctoral experience, and their research ideas. (Re)presenting their transcribed talk as poetry involves culling and playing with words, phrases and segments, making changes in spacing, lines and rhythm to arrive at an evocative distillation (Butler-Kisber, 2002). This process enables each person to bring stories and/or fragments of experience into critical engagement with others. Poetic thinking functions pedagogically, helping students find a critical voice to enliven and hone their reflexive writing in relation to their doctoral experience and their research positioning. Arts-based methods of inquiry are an ongoing topic of interest in research communities. Found poetry is a useful starting point to explore creative means by which research participants can recount their stories, and equally, by which researchers can witness and disseminate what they have to tell.self funde

Tissue-engineered tracheal replacement in a child: a 4-year follow-up study

In 2010, a tissue-engineered trachea was transplanted into a 10-year-old child using a decellularized deceased donor trachea repopulated with the recipient's respiratory epithelium and mesenchymal stromal cells. We report the child's clinical progress, tracheal epithelialization and costs over the 4 years. A chronology of events was derived from clinical notes and costs determined using reference costs per procedure. Serial tracheoscopy images, lung function tests and anti-HLA blood samples were compared. Epithelial morphology and T cell, Ki67 and cleaved caspase 3 activity were examined. Computational fluid dynamic simulations determined flow, velocity and airway pressure drops. After the first year following transplantation, the number of interventions fell and the child is currently clinically well and continues in education. Endoscopy demonstrated a complete mucosal lining at 15 months, despite retention of a stent. Histocytology indicates a differentiated respiratory layer and no abnormal immune activity. Computational fluid dynamic analysis demonstrated increased velocity and pressure drops around a distal tracheal narrowing. Cross-sectional area analysis showed restriction of growth within an area of in-stent stenosis. This report demonstrates the long-term viability of a decellularized tissue-engineered trachea within a child. Further research is needed to develop bioengineered pediatric tracheal replacements with lower morbidity, better biomechanics and lower costs

Temporal drag: transdisciplinarity and the 'case' of psychosocial studies

Psychosocial studies is a putatively ‘new’ or emerging field concerned with the irreducible relation between psychic and social life. Genealogically, it attempts to re-suture a tentative relation between mind and social world, individual and mass, internality and externality, norm and subject, and the human and non-human, through gathering up and re-animating largely forgotten debates that have played out across a range of other disciplinary spaces. If, as I argue, the central tenets, concepts and questions for psychosocial studies emerge out of a re-appropriation of what have become anachronistic or ‘useless’ concepts in other fields – ‘the unconscious’, for instance, in the discipline of psychology – then we need to think about transdisciplinarity not just in spatial terms (that is, in terms of the movement across disciplinary borders) but also in temporal terms. This may involve engaging with theoretical ‘embarrassments’, one of which – the notion of ‘psychic reality’ – I explore here

Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

<p>Abstract</p> <p>Background</p> <p>Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (T_max range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques.</p> <p>Methods</p> <p>Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, <it>n</it> = 74) and control (CON, <it>n</it> = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5.</p> <p>Results</p> <p>Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (<it>p</it> < 0.001 <it>vs</it>. CON). Exercise-induced BM loss was 2.4 (1.2)% (<it>p</it> < 0.001). Pre- to post-stage BM gains were observed in 26% of UER along competition. Pre- and post-stage plasma osmolality remained within normal clinical reference range (280 to 303 mOsmol/kg) in the majority of UER (<it>p</it> > 0.05 <it>vs</it>. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in <it>n</it> = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (<it>p</it> < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (<it>p</it> < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON.</p> <p>Conclusion</p> <p>Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.</p

Left gaze bias in humans, rhesus monkeys and domestic dogs

While viewing faces, human adults often demonstrate a natural gaze bias towards the left visual field, that is, the right side of the viewee’s face is often inspected first and for longer periods. Using a preferential looking paradigm, we demonstrate that this bias is neither uniquely human nor limited to primates, and provide evidence to help elucidate its biological function within a broader social cognitive framework. We observed that 6-month-old infants showed a wider tendency for left gaze preference towards objects and faces of different species and orientation, while in adults the bias appears only towards upright human faces. Rhesus monkeys showed a left gaze bias towards upright human and monkey faces, but not towards inverted faces. Domestic dogs, however, only demonstrated a left gaze bias towards human faces, but not towards monkey or dog faces, nor to inanimate object images. Our findings suggest that face- and species-sensitive gaze asymmetry is more widespread in the animal kingdom than previously recognised, is not constrained by attentional or scanning bias, and could be shaped by experience to develop adaptive behavioural significance

The transcriptional response of Caenorhabditis elegans to ivermectin exposure identifies novel genes involved in the response to reduced food intake

We have examined the transcriptional response of Caenorhabditis elegans following exposure to the anthelmintic drug ivermectin (IVM) using whole genome microarrays and real-time QPCR. Our original aim was to identify candidate molecules involved in IVM metabolism and/or excretion. For this reason the IVM tolerant strain, DA1316, was used to minimise transcriptomic changes related to the phenotype of drug exposure. However, unlike equivalent work with benzimidazole drugs, very few of the induced genes were members of xenobiotic metabolising enzyme families. Instead, the transcriptional response was dominated by genes associated with fat mobilization and fatty acid metabolism including catalase, esterase, and fatty acid CoA synthetase genes. This is consistent with the reduction in pharyngeal pumping, and consequential reduction in food intake, upon exposure of DA1316 worms to IVM. Genes with the highest fold change in response to IVM exposure, cyp-37B1, mtl-1 and scl-2, were comparably up-regulated in response to short–term food withdrawal (4 hr) independent of IVM exposure, and GFP reporter constructs confirm their expression in tissues associated with fat storage (intestine and hypodermis). These experiments have serendipitously identified novel genes involved in an early response of C. elegans to reduced food intake and may provide insight into similar processes in higher organisms