Creating and sharing : teens' information practices in digital communities

Introduction In a connected world youth are participating in digital content creating communities. This paper introduces a description of teens' information practices in digital content creating and sharing communities. Method The research design was a constructivist grounded theory methodology. Seventeen interviews with eleven teens were collected and observation of their digital communities occurred over a two-year period. Analysis The data were analysed iteratively to describe teens' interactions with information through open and then focused coding. Emergent categories were shared with participants to confirm conceptual categories. Focused coding provided connections between conceptual categories resulting in the theory, which was also shared with participants for feedback. Results The paper posits a substantive theory of teens' information practices as they create and share content. It highlights that teens engage in the information actions of accessing, evaluating, and using information. They experienced information in five ways: participation, information, collaboration, process, and artefact. The intersection of enacting information actions and experiences of information resulted in five information practices: learning community, negotiating aesthetic, negotiating control, negotiating capacity, and representing knowledge. Conclusion This study contributes to our understanding of youth information actions, experiences, and practices. Further research into these communities might indicate what information practices are foundational to digital communities.

Antibodies mediate formation of neutrophil extracellular traps in the middle ear and facilitate secondary pneumococcal otitis media

Otitis media (OM) (a middle ear infection) is a common childhood illness that can leave some children with permanent hearing loss. OM can arise following infection with a variety of different pathogens, including a coinfection with influenza A virus (IAV) and Streptococcus pneumoniae (the pneumococcus). We and others have demonstrated that coinfection with IAV facilitates the replication of pneumococci in the middle ear. Specifically, we used a mouse model of OM to show that IAV facilitates the outgrowth of S. pneumoniae in the middle ear by inducing middle ear inflammation. Here, we seek to understand how the host inflammatory response facilitates bacterial outgrowth in the middle ear. Using B cell-deficient infant mice, we show that antibodies play a crucial role in facilitating pneumococcal replication. We subsequently show that this is due to antibody-dependent neutrophil extracellular trap (NET) formation in the middle ear, which, instead of clearing the infection, allows the bacteria to replicate. We further demonstrate the importance of these NETs as a potential therapeutic target through the transtympanic administration of a DNase, which effectively reduces the bacterial load in the middle ear. Taken together, these data provide novel insight into how pneumococci are able to replicate in the middle ear cavity and induce disease.

Geographic co-distribution of influenza virus subtypes H7N9 and H5N1 in humans, China

Human infection with a novel low pathogenicity influenza A(H7N9) virus in eastern China has recently raised global public health concerns (1). The geographic sources of infection have yet to be fully clarified, and confirmed human cases from 1 province have not been linked to those from other provinces. While some studies have identified epidemiologic characteristics of subtype H7N9 cases and clinical differences between these cases and cases of highly pathogenic influenza A(H5N1), another avian influenza affecting parts of China (2–4), the spatial epidemiology of human infection with influenza subtypes H7N9 and H5N1 in China has yet to be elucidated. To test the hypothesis of co-distribution of high-risk clusters of both types of infection, we used all available data on human cases in mainland China and investigated the geospatial epidemiologic features...

Experiments in autonomous underground guidance

This paper presents the results of an experimental program for evaluating sensors and sensing technologies in an underground mining applications. The objective of the experiments is to infer what combinations of sensors will provide reliable navigation systems for autonomous vehicles operating in a harsh underground environment. Results from a wide range of sensors are presented and analysed. Conclusions as to a best combination of sensors are drawn.

A Chlamydia trachomatis strain with a chemically generated amino acid substitution (P370L) in the cthtrA gene shows reduced elementary body production

Background Chlamydia (C.) trachomatis is the most prevalent bacterial sexually transmitted infection worldwide and the leading cause of preventable blindness. Genetic approaches to investigate C. trachomatis have been only recently developed due to the organism’s intracellular developmental cycle. HtrA is a critical stress response serine protease and chaperone for many bacteria and in C. trachomatis has been previously shown to be important for heat stress and the replicative phase of development using a chemical inhibitor of the CtHtrA activity. In this study, chemically-induced SNVs in the cthtrA gene that resulted in amino acid substitutions (A240V, G475E, and P370L) were identified and characterized. Methods SNVs were initially biochemically characterized in vitro using recombinant protein techniques to confirm a functional impact on proteolysis. The C. trachomatis strains containing the SNVs with marked reductions in proteolysis were investigated in cell culture to identify phenotypes that could be linked to CtHtrA function. Results The strain harboring the SNV with the most marked impact on proteolysis (cthtrAP370L) was detected to have a significant reduction in the production of infectious elementary bodies. Conclusions This provides genetic evidence that CtHtrA is critical for the C. trachomatis developmental cycle.

Influence of posture and frequency modes in total body water estimation using bioelectrical impedance spectroscopy in boys and adult males

The aim of the study was to examine differences in total body water (TBW) measured using single-frequency (SF) and multi-frequency (MF) modes of bioelectrical impedance spectroscopy (BIS) in children and adults measured in different postures using the deuterium (2H) dilution technique as the reference. Twenty-three boys and 26 adult males underwent assessment of TBW using the dilution technique and BIS measured in supine and standing positions using two frequencies of the SF mode (50 kHz and 100 kHz) and the MF mode. While TBW estimated from the MF mode was comparable, extra-cellular fluid (ECF) and intra-cellular fluid (ICF) values differed significantly (p < 0.01) between the different postures in both groups. In addition, while estimated TBW in adult males using the MF mode was significantly (p < 0.01) greater than the result from the dilution technique, TBW estimated using the SF mode and prediction equation was significantly (p < 0.01) lower in boys. Measurement posture may not affect estimation of TBW in boys and adult males, however, body fluid shifts may still occur. In addition, technical factors, including selection of prediction equation, may be important when TBW is estimated from measured impedance.

Fibre Transfer in Merino Ewes Mated with Damara, Merino or Dorper Rams in Central Western Queensland

Considerable concern has been expressed by the Australian wool industry regarding the contamination of the clip with coloured or kempy fibres from imported breeds of sheep. As part of the evaluation of imported sheep meat breeds in western Queensland, a study is examining fibre growth and transfer of fibres and the potential to cause physical contamination of Merino fleeces. The breeds of concern in this study are the Damara, a fat-tailed breed with a hairy, coloured fleece and the Dorper which has both pigmented fibres and a kempy fleece which is shed cyclically. Three groups of Merino 27 ewes were mated to Merino, Damara and Dorper rams respectively and fibre transfer to the Merino ewes during mating, from lambing to weaning and during grazing, assessed. Both a direct field method and a laboratory method (Hatcher 1995) are being used. Those measured by direct count were measured immediately after joining and 2, 4 and 8 weeks subsequently. and the other ewes were shorn and sampled and measured in the laboratory using the dark fibre detector. This paper presents preliminary findings of those ewes monitored by the direct field method. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

Kaunhiista kauhniiseen, satheesta satteeseen : Jälkitavuissa säilyneen h:n variaatiosta Pellossa vuoden 1995 aineiston valossa

Tutkielmassa tarkastellaan jälkitavuissa säilyneen, alun perin vokaalienvälisen h:n nykyedustusta Tornionlaakson Pellossa sosiolingvistisen teorian valossa. Keskeisenä tutkimusongelmana on variaation jasen muuttumisen suunnan selvittäminen, mitä tutkitaan sekä näennäis- että reaaliajallisen metodin turvin. Lisäksi pohditaan, millaiset kielensisäiset tekijät muutoksia ohjaavat. Reaaliaikaisen vertailun mahdollistavat Kirsi Kunnarin vuonna 1983 valmistuneen pro gradu -työn jälkitavujen h:ta koskevat tulokset Pellosta (informantit syntyneet vuosina 1898-1967). Pääpaino on kuitenkin näennäisajallisessa vertailussa; variaatiota tarkastellaan yksityiskohtaisesti erityisesti kielelliseltä kannalta, mikä on vaatinut perusteellista aineiston käsittelyä. Näennäisajallisessa tarkastelussa verrataankahden haastatellun ikäryhmän kieltä: nuorten (syntyneet vuosina 1986-1977) ja keski-ikäisten (syntyneet vuosina 1964-1945). Nuoria informantteja, joita on 14, on haastateltu pääosin pareittan. Vertailuryhmä, keski-ikäiset, koostuu heidän vanhem mistaan (7 informanttia). Nauhatunteja on yhteensä n. 13. Tulokset osoittavat, että toisin kuin muualla Peräpohjolassa, yleiskielen mukainen katovariantti (kou-luun) ei ole merkittävästi yleistynyt pellolaisten puhekielessä viimeisten neljän sukupolven aikana. Vokaalienvälisessä asemassa (koulu-h-un) h:ta ei nykypellolaisilla enää tapaa, ja ns. sisäheittoinenvariantti (koul-huun) on nuorten ryhmässä selvästi vähemmän suosiossa kuin keski-ikäisillä. Tornionjoki­laaksolainen, metateettinen h-variantti (kouh-luun) on yhä elinvoimainen: sen käyttö on nuorillakin lisääntynyt. Metateesi ei ole kuitenkaan kvantitatiivisesti juurikaan yleistynyt niissä fonotaktisissa ympäristöissä, joissa se aiheesta tehdyn väitöskirjan (1992) mukaan on ollut aiemmilla sukupolvilla harvinainen. Tätä saattaa osittain selittää tiettyjen puhekielisyyksien yleistyvä käyttö, mikä vaikuttaa eniten juuri näissä fonotaktisissa ympäristöissä siten, ettei metateesin toteutumiselle ole edellytyksiä. Pellon nykyisessä jälkitavujen h:n variaatiossa on osallisena vielä yksi variantti: assimiloitunut h (talhoon > talloon; toisheen > toisseen; kauphaan > kauppaan). Aiemmin tutkituilla sukupolvilla assimilaatiomuutos on ollut harvinainen, mutta nyt se on yleistynyt erityisesti nuorilla tytöillä. h:n assimilaatiossa syntyvät muodot lankeavat usein yhteen alueella jokseenkin fonemaattisena esiintyvän yleisgeminaation kanssa, osa muodoista muistuttaa erikoisgeminaatiota ja pieni osa yleiskielisiä muotoja. Tutkielmassa kyseenalaistetaan kielellisten seikkojen nojalla kyseisten muotojen tulkitseminen h:n assimilaatiosta johtuvaksi: assimiloituneiksi tulkituissa h-tapauksissa sekä konsonantin että sitä seuraavan vokaalin pituusdistribuutiot tukevat ajatusta, että ainakin yleisgeminaatiokonteksteissa assimilaatiomuodot ovat puhujan kannalta "mentaalista geminaatiota". Assimilaatiomuodot rinnastetaan tutkielmassa katomuotoihin sikäli, että niissäkin h on tasoittunut. Merkittävä ero on tavujen kvantiteettisuhteissa: assimilaatiomuodoissa ne säilyvät ennallaan (tal-hoon > tal-loon), katomuodoissa muuttuvat (ta-loon). h:n assimilaatiolla ja metateesilla epäillään aineistonperusteella olevan yhteisen tehtävän: sisäheittoisten talhoon, satheen -muotojen karttaminen tavujen kavantiteettisuhteita rikkomatta. Esitetyn hypoteesin mukaan syynä ovat suomen fonotaksille vieraat konsonantin + h:n yhtymät, jotka aikoinaan syntyivät murteeseen vokaalin heityttyä h:n edeltä.

Nutritional management for reproductive efficiency

Nutrition influences reproductive efficiency and the survival of lambs and weaners but the costs of supplementary feeding or maintaining low stocking rates are not justified by the resulting income from higher lamb weaning rates and reduced weaner mortality. The current practice of segmenting the ewe flock using ultrasound scanning to determine the number of foetuses still results in groups of ewes with a wide range of condition scores and with widely differing nutritional requirements. This report describes an approach to precision management of pregnant ewes and weaners that is based on the e-sheep platform of technologies and uses computer-directed drafting for nutritional management of individual animals and walk-through weighing to monitor changing nutritional status. It is estimated that the cost of feeding a thousand-ewe flock can be reduced from $14,000 for feeding all animals to $3300 for targeted feeding of 25% of ewes requiring additional nutrition and 20% of weaners at risk of dying. The cost of the targeted feeding strategy is more than justified by the value of additional 12-month-old animals, which is $9000. The e-sheep precision nutrition system is not attractive to industry at this stage because of the cost of the e-sheep infrastructure, the perceived complexity of the technology and the requirement for further research, but it is expected to be a commercial option within three years.

Studio portrait of Josef Molling with unidentified man; Heidelberg, Germany.

right: Joseph Molling sitting; left: unknown man standing

Studio portrait of Josef Molling with unidentified man; Heidelberg, Germany.

right: Joseph Molling sitting; left: unknown man standing

Studio portrait of Josef Molling's fraternity; Heidelberg, Germany.

Josef Molling is sitting on the left

Resin defect impacts on the value of graded recovery and evaluation of technologies for internal defect detection in slash pine logs.

The key outcome will be to identify a technology that is practical to use to scan logs identified by the modelling as suspect or marginal for sawing and to confirm their unsuitability for value adding sawing by internal scanning.

Studio portrait of Josef Molling's fraternity; Heidelberg, Germany.

Josef Molling is sitting on the left