2,692 research outputs found

    Tender Places: The Claypans Diaries, Part 1 and 2

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    Tender Places is a creative research project engaging the settler body in reflexive dialogue with theory in and through place, to explore moral responsibilities of settler descended peoples in the time of ecological breakdown. The entanglement of severance and extraction with ecological and social violence poses a provocation to settler descended peoples. Working with the Ilparpa Claypans, a site of personal significance on the outskirts of Alice Springs in the Northern Territory, my creative research uses Deborah Bird Rose’s provocation of “Taking Notice,” sensual language and presencing the co-existence of love and violence in order to mobilise the body in the act of physical translation of ideas with/in place through walking, writing and digital photography. The research acknowledges and activates trans-local relationships through the creation and sending of postcards that document, translate and disseminate field notes to and through an international network of artist peers. The postcard is presented as a queering material medium; an appropriated artefact of outsider privilege, a public/ private artwork for an audience of one, and a material item that crosses political and geographical borders to link places and people through space and time. My paper locates this practice of (trans)local place-based inquiry into ecological crisis within broader decolonising, feminist and creative inquiries into the Anthropocene. Postcards and other creative research artefacts will be shared to demonstrate the methodology in action, and I reflect on the decolonising potential of reflexive and embodied engagement with place in relation to settler identity

    Ecotoxicological Risk Assessment: Developments in PNEC Estimation

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    Ecotoxicological risk assessment must be undertaken before a chemical can be deemed safe for application. The assessment is based on three components: hazard assess- ment, exposure assessment and risk characterisation. The latter is a combination of the former two. One standard approach is based on the deterministic comparison of exposure concentration estimates to the concentration of the toxicant below which adverse effects are unlikely to occur to the potentially exposed ecological assemblage. This concentration is known as the ‘predicted no effect concentration’ (PNEC). At the level of hazard assessment we are concerned with, there is a requirement that procedures be straightforward and efficient, as well as being transparent. The PNEC is in general currently determined using either a fixed assessment factor applied to a summary statistic of observed laboratory derived toxicity data, or as a percentile of a distribution over the ecological community sensitivity. Often it is the situation that a hazard assessment will be based on substantially small samples of data. In this thesis we evaluate proposals for determining a PNEC according to reg- ulatory guidance and scientific literature. In particular, we explore these methods under the context of alternative probabilistic models. We also focus on the deter- mination of conservative probabilistic estimators, which may be appropriate for this level of risk assessment. Additionally, we also discuss the detection of species non- exchangeability, a concept which is recognised by scientists and risk assessors, yet typically discounted in practice. A proposal on incorporating knowledge of a non-exchangeable species for probabilistic estimators is discussed and evaluated. The final topic of research examines a generalised deterministic estimator proposed in a recent European Food Safety Agency report. In particular, we analyse the ro- bustness and analytical properties of some cases of this estimator which (at least) maintains the expected level of protection currently attributed. Proposals made within this thesis, many of which extend upon what is currently scientifically accepted, satisfy the requirements of being tractably straightforward to apply and are scientifically defensible. This will appeal to end users and increase the chances of gaining regulatory acceptance. All developments are fully illustrated with real-life examples

    Nimbus-7 ERB Solar Analysis Tape (ESAT) user's guide

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    Seven years and five months of Nimbus-7 Earth Radiation Budget (ERB) solar data are available on a single ERB Solar Analysis Tape (ESAT). The period covered is November 16, 1978 through March 31, 1986. The Nimbus-7 satellite performs approximately 14 orbits per day and the ERB solar telescope observes the sun once per orbit as the satellite crosses the southern terminator. The solar data were carefully calibrated and screened. Orbital and daily mean values are given for the total solar irradiance plus other spectral intervals (10 solar channels in all). In addition, selected solar activity indicators are included on the ESAT. The ESAT User's Guide is an update of the previous ESAT User's Guide (NASA TM 86143) and includes more detailed information on the solar data calibration, screening procedures, updated solar data plots, and applications to solar variability. Details of the tape format, including source code to access ESAT, are included

    Engaged in Research/Achieving Balance: A Case Example of Teaching Research to Masters of Social Work Students

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    This article considers the use of participatory action research and Photovoice as a tool for engaging graduate level social work students in research education. Photovoice is an investigative tool that assists people in critically reflecting on the everyday social and political realities of their lives, enriching their understanding of their communities and the issues pertinent to them, while at the same time, giving them a voice from which to educate others on these issues. In the context of a group assignment, 26 social work students, enrolled in an introductory graduate research course, were asked to reflect upon the question, “What does balance look like for you in the MSW program?” Thirty-two photographs with captions were submitted and analyzed by class members for relevant themes. Balance was described as existing along a continuum from balanced to unbalanced and was comprised of four major themes: connection, nurturance, keeping perspective, and disengagement. Although this teaching strategy was not formally assessed, preliminary impressions are that students benefited from participating in the Photovoice activity

    High speed video capture for mobile phone cameras

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    We consider an electromechanical model for the operation of a voice coil motor in a mobile phone camera, with the aim of optimizing how a lens can be moved to a desired focusing motion. Although a methodology is developed for optimizing lens shift, there is some concern about the experimentally-determined model parameters that are at our disposal. Central to the model is the value of the estimated magnetic force constant, Kf: its value determines how far it is actually possible to move lens, but it appears that, from the value given, it would not be possible to shift the lens through the displacements desired. Furthermore, earlier experiments have also estimated the value of the back EMF constant, Kg , to be roughly five times greater than Kf, even though we present two theoretical arguments that show that Kf = Kg: a conclusion supported by readily-available manufacturers’ data

    Controlling gene expression in mycobacteria with anhydrotetracycline and Tet repressor

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    Gene expression systems that allow the regulation of bacterial genes during an infection are valuable molecular tools but are lacking for mycobacterial pathogens. We report the development of mycobacterial gene regulation systems that allow controlling gene expression in fast and slow-growing mycobacteria, including Mycobacterium tuberculosis, using anhydrotetracycline (ATc) as inducer. The systems are based on the Escherichia coli Tn10-derived tet regulatory system and consist of a strong tet operator (tetO)-containing mycobacterial promoter, expression cassettes for the repressor TetR and the chemical inducer ATc. These systems allow gene regulation over two orders of magnitude in Mycobacterium smegmatis and M.tuberculosis. TetR-controlled gene expression was inducer concentration-dependent and maximal with ATc concentrations at least 10- and 20-fold below the minimal inhibitory concentration for M.smegmatis and M.tuberculosis, respectively. Using the essential mycobacterial gene ftsZ, we showed that these expression systems can be used to construct conditional knockouts and to analyze the function of essential mycobacterial genes. Finally, we demonstrated that these systems allow gene regulation in M.tuberculosis within the macrophage phagosome

    Rapid Generation Advance in Chickpea for Accelerated Breeding Gain in Ethiopia: : What Speed Breeding Imply?

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    አህፅሮት  ሽምብራ በሀገራችን በተለያዩ ስነ-ምህዳራትና የአዘማመር ስርዓት ውስጥ የሚመረት ሰብል ነው፡፡ የሰብሉ የመድረሻ ተለያይነት በዓለም ላይ ከ80 አስከ 180 ቀናት ይደርሳል፡፡ እያደገ ያለውን ህዝብና የተለያዩ ፍላጎቶችን ለመመለስ የሰብል ማሻሻያ ስርዓቱ ጊዜን በቆጠበ ሁኔታ መከወን የሚያስችሉ ዘዴዎችን መጠቀሙ አንዱ የችግሩ መፍቻ መንገድ ነው፡፡ በዚህ ጥናት ላይ የሰብሉን ማሻሻያ ለማፍጠን እንዴት በርካታ ትውልዶቸን በአንድ ዓመት ማግኘት እንደሚቻል ቀርቧል፡፡ አስር የሚሆኑ ምርት ላይ ያሉ የሽምብራ ዝርያዎችን ከሌሎች ዘጠኝ በዘመናዊ ላብራቶሪ ልየታ ድርቅን የሚቋቋም ባህሪ ያላቸውን ቤተሰቦቸ በማዳቀል ሂደት ወደ 46 ግንኙነቶችን መፍጠር የተቻለበትንና ትውልዶችን ማፍጠንንና ማግኘትን በትኩረት ተከናውኗል፡፡ ዓላማውም ድርቅን የሚቋቋሙና ምርታማ ትውልዶችን ፍተሻ ማድረግ ሲሆን ይህንንም ባጭር ጊዜ ውስጥ ለመከወን አዲስ የነጠላ ዘር ትውልድ ማሻገሪያ ስርዓትን ከቀድሞ ደራሽ እምቡጦች ጋር በማቀናጀት አራት ትውልዶችን በዓመት ማግኘት የተቻለበትን ሁኔታ ማረጋገጥ ተችሏል፡፡ ይህ ትውልዶችን የማስኬድ ሁኔታ በአንድ አመት ጊዜ ውስጥ በወረርና የደብረዘይት ማእከላት የሙከራ ማሳዎችን በመጠቀም የተሰራ ጥናት ሲሆን በውጤቱም ቀድሞ ደራሽ እምቡጦችን ለማግኘት ከ80-85 ቀናት ብቻ የፈጀ ነበር፡፡ ትውልዶቹ የመካከለኛ መድረሻ ጊዜ ያለው ውስጥ የሚመደቡ ሲሆን በዚህ ስሌት የዝርያ መልቀቂያ ጊዜውን ከተለመደው 10-12 ዓመታት 50 በመቶ በመቀነስ የአማራጭ ቴክኖሎጂ አቅርቦትና ምርታማነት እንዲሁም አዋጭነት ላይ ከፍተኛ አስተዋፅዖ ያለው ውጤት አመላክቷል፡፡ ይህ ቴክኒክ በቶሎ የመድረሻ ዕድሜ ያላቸው ላይ ተፅዕኖው አስከ ስድስት ትውልድ በዓመት ማስገኘት እንደሚያስችል የተሰላ ሲሆን በቀላሉ የሚለመድ፣ በጥቂት የመዋዕለ ነዋይ፣ ፋሲሊቲና ክህሎት በትሮፒካል ንፍቀ-ክበብ ውስጥ አገልግሎት ላይ ሊውል የሚችልና ቴክኖሎጂ ለቀቃን ብሎም መተካካትን የሚያፋጥን፤ በዚህም ረገድ የምርታማነት እመርታን የሚያስገኝ የተሻሻለ ዘዴ እንደሆነ መገንዘብ ተችሏል፡፡ Abstract Chickpea (Cicer arietinum L.) is grown in a wide range of environments and cropping systems and its maturity ranges from 80 to 180 days. Time-saving breeding is key to responding to the dynamics of demands and environmental changes. The study employed the Single Seed Descent (SSD) technique in advancing the generation, supported by the independent observation of chickpea seed germination and seedling establishment in the seed lab. The filial generation nursery was derived from 46 initial crosses with the aim of enhancing drought and yield response of otherwise commercial 10 cultivars. Between 5 December 2017 and 20 December 2018 we were able to obtain four rounds of working chickpea seeds (F2-F5) using two research locations. The average time required to obtain early matured pods varied from 80 to 85 days. Harvesting four generations in an annual cycle enables a saving of at least 50% time in variety release, which has the potential to double the rate of genetic gain and variety replacement. As long as measures are taken to reduce risk associated with extreme weather events or animal damage, this low-cost rapid cycling approach could be adapted for large-scale breeding programs to fast track the development of more productive varieties
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