694 research outputs found
DFDs:Evolutionary Status andA Cognitive Based Empirical Investigation of Level 0 DFD Clarity
The data flow diagram (DFD) has been a development, communication, and documentation technique in the systems analyst toolbox for almost two decades. Both surveys and expert opinion confirm that the data flow diagram is a popular and most preferred tool of its class structured analysis and design tools (Whitten,Bentley, & Ho, 1986, p.221). Recent surveys indicate as much as an 80% usage of DFDs (Jain & Purao, 1991; Martin, M., 1991, p.98). These surveys also indicate that of all the structured tools , the DFD is consistently used more than the others. Numerous authors attest to the DFD\u27s popularity (Vessey & Conger, 1994; Vessey, Jarvenpaa, & Tractinsky, 1992; France, 1992; Kung 1991; Abrahami 1993, Liu, 1993; Warren, Stott, & Norcio, 1991; Protsko, Sorenson, Tremblay, & Schaefer, 1991; Capron, 1986; Gore & Stubbe, 1988; Kendall & Kendall, 1988; Martin & McClure, 1985; Martin, M., 1991; Powers, Cheney, & Crow, 1990; Wetherbe, 1988; Whitten, Bentley, & Ho, 1986; Yourdon, 1989, etc)
Estuary environmental flows assessment methodology for Victoria
This report sets out a method to determine the environmental water requirements of estuaries in Victoria. The estuary environmental flows assessment method (EEFAM) is a standard methodology which can be applied consistently across Victorian estuaries.The primary objective of EEFAM is to define a flow regime to maintain or enhance the ecological health of an estuary. The method is used to inform Victorian water resource planning processes.The output of EEFAM is a recommended flow regime for estuaries. This recommendation is developed from the known dependence of the estuary’s flora, fauna, biogeochemical and geomorphological features on the flow regime. EEFAM is an evidence-based methodology. This bottom-up or ‘building block’ approach conforms to the asset-based approach of the Victorian River Health Strategy and regional river health strategies.EEFAM is based on and expands on FLOWS, the Victorian method for determining environmental water requirements in rivers. The list of tasks has been modified and re-ordered in EEFAM to reflect environmental and management issues specific to estuaries. EEFAM and FLOWS can be appliedsimultaneously to a river and its estuary as part of a whole-of-system approach to environmental flow requirements. Like the FLOWS method, EEFAM is modular, and additional components can be readily incorporated
The three dimensional microstructural network of elastin, collagen and cells in Achilles tendons
Similar to most biological tissues, the biomechanical and functional characteristics of the Achilles tendon are closely related to its composition and microstructure. It is commonly reported that type I collagen is the predominant component of tendons and is mainly responsible for the tissue's function. Although elastin has been found in varying proportions in other connective tissues, previous studies report that tendons contain very small quantities of elastin. However, the morphology of and the microstructural relationship among the elastic fibres, collagen and cells in tendon tissue have not been well examined. We hypothesize the elastic fibres, as another fibrillar component in the extracellular matrix, have a unique role in mechanical functions and microstructural arrangement in Achilles tendons. Using confocal and Second Harmonic Generation (SHG) imaging techniques, this study examined the 3-dimensional microstructure of the collagen, elastin and cells in the mid-portion of hydrated rabbit Achilles tendons. It has been shown that elastic fibres present a close connection with the tenocytes. The close relationship of the three components has been revealed as a distinct, integrated and complex microstructural network. Notably, a "spiral" structure within fibril bundles in Achilles tendons was observed in some samples in specialized regions. This study substantiates the hierarchical system of the spatial microstructure of tendon, including the mapping of collagen, elastin and tenocytes, with 3-dimensional confocal images
Violence, alcohol and symptoms of depression and in Cape Town's poorest communities: results of a community survey
Introduction
This paper summarises key findings from the first of three household surveys conducted in three high-violence areas in the Cape Town, investigating community membersâ experiences of alcohol use, their built environment, violence and symptoms of depression, together with their views on alcohol and other interventions.
Methods
A stratified random sample of 1500 dwellings, 1200 in Khayelitsha and 300 in Gugulethu and Nyanga (âGunyaâ) was selected using GIS address data for formal areas and aerial photography for informal areas. Fieldwork took place from July to November 2013. Responses to questions were summarized by area, gender, age and formal vs. informal settlement type.
Results
After substitution and data cleaning, 1213 Khayelitsha households and 286 Gunya households were included. In Gunya, 29% of respondents reported that they or their family members had been affected by at least one violent crime (murder, assault, domestic violence, rape) in the past year, compared with 12% in Khayelitsha. Using a CES-D-10 cut-off of 10, 44% of respondents were classified as depressed. More than half the respondents reported having experienced some form of alcohol nuisance. Respondents were supportive of alcohol interventions such as increased taxes and police regulation of outlets, particularly in Gunya (87%) and amongst female respondents (76%). Satisfaction with infrastructure such as street lighting and drainage was generally low.
Conclusions
The results describe the co-occurring burdens of alcohol and drug use, violence, depression and deprivation in our study populations
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High-precision 41K/39K measurements by MC-ICP-MS indicate terrestrial variability of δ41K
Potassium is a major component in continental crust, the fourth-most abundant cation in seawater, and a key element in biological processes. Until recently, difficulties with existing analytical techniques hindered our ability to identify natural isotopic variability of potassium isotopes in terrestrial materials. However, measurement precision has greatly improved, and a range of K isotopic compositions has now been demonstrated in natural samples. In this study, we present a new technique for high-precision measurement of K isotopic ratios using high-resolution, cold
plasma multi-collector mass spectrometry. We apply this technique to demonstrate natural variability in the ratio of 41K to 39K in a diverse group of geological and biological samples, including silicate and evaporite minerals, seawater, and plant and animal tissues. The total range in 41K/39K ratios is ca. 2.6â°, with a long-term external reproducibility of 0.17â° (2Ď, N=108). Seawater and seawater-derived evaporite minerals are systematically enriched in 41K compared to silicate minerals by ca. 0.6â°, a result consistent with recent findings (1, 2). Although our average bulk-
silicate Earth value (-0.54â°) is indistinguishable from previously published values, we find systematic δ41K variability in some high-temperature sample suites, particularly those with evidence for the presence of fluids. The δ41K values of biological samples span a range of ca. 1.2â° between terrestrial mammals, plants, and marine organisms. Implications of terrestrial K isotope variability for the atomic weight of K and K-based geochronology are discussed. Our results indicate that high-precision measurements of stable K isotopes, made using commercially available
mass spectrometers, can provide unique insights into the chemistry of potassium in geological and biological systems
Multi-scale environmental filters and niche partitioning govern the distributions of riparian vegetation guilds
Across landscapes, riparian plant communities assemble under varying levels of disturbance, environmental stress, and resource availability, leading to the development of distinct riparian life-history guilds over evolutionary timescales. Identifying the environmental filters that exert selective pressures on specific riparian vegetation guilds is a critical step in setting baseline expectations for how riparian vegetation may respond to environmental conditions anticipated under future global change scenarios. In this study, we ask: (1) What riparian plant guilds exist across the interior Columbia and upper Missouri River basins? (2) What environmental filters shape riparian guild distributions? (3) How does resource partitioning among guilds influence guild distributions and co-occurrence? Woody species composition was measured at 703 stream reaches and each species\u27 morphological and functional attributes were extracted from a database in four categories: (1) life form, (2) persistence and growth, (3) reproduction, and (4) resource use. We clustered species into guilds by morphological characteristics and attributes related to environmental tolerances, modeling these guilds\u27 distributions as a function of environmental filters-regional climate, watershed hydrogeomorphic characteristics, and stream channel form- and guild coexistence. We identified five guilds: (1) a tall, deeply rooted, long-lived, evergreen tree guild, (2) a xeric, disturbance tolerant shrub guild, (3) a hydrophytic, thicket-forming shrub guild, (4) a low-statured, shadetolerant, understory shrub guild, and (5) a flood tolerant, mesoriparian shrub guild. Guilds were most strongly discriminated by species\u27 rooting depth, canopy height and potential to resprout and grow following biomass-removing disturbance (e.g., flooding, fire). Hydro-climatic variables, including precipitation, watershed area, water table depth, and channel form attributes reflective of hydrologic regime, were predictors of guilds whose life history strategies had affinity or aversion to flooding, drought, and fluvial disturbance. Biotic interactions excluded guilds with divergent life history strategies and/or allowed for the co-occurrence of guilds that partition resources differently in the same environment. We conclude that the riparian guild framework provides insight into how disturbance and bioclimatic gradients shape riparian functional plant diversity across heterogeneous landscapes. Multiple environmental filters should be considered when the riparian response guild framework is to be used as a decisionsupport tool framework across large spatial extents. Copyright: Š 2015 Hough-Snee et al
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Photochemistry of ketones adsorbed on size/shape selective zeolites. A supramolecular approach to persistent carbon centered radicals
2H NMR, EPR, computational and product analyses of the photolysis of 2,4-diphenylpentan-3-one (DPP) adsorbed on MFI size/shape selective zeolites are consistent with supramolecular structural changes as a function of surface coverage that provide a novel method for the generation of persistent diffusing organic free radicals
Tracking Onslow: a community in transition. edition 5, October 2014
This is the fifth edition of Tracking Onslow and the first that is not the result of a visit to the town. In June 2014 we were told that the Shire would not be funding the flights, accommodation or printing for the edition and so the ECU crew looked for other ways to continue documenting the impact of Wheatstone and Macedon on Onslow.
Fortunately, our previous visits in July 2012, February 2013, July 2013 and February 2014 had filled our contact books with names and numbers and clued us in to issues that needed to be followed up.
After a phone around for updates it was clear that this is not the time to be letting go of the process of documenting the challenges facing the Onslow community.
We are very grateful to teacher James Trimble and his students, Amber and Taylor, for helping with the In Your Words section. Weâd also like to thank everyone who spoke to us by phone and sent us images.
We heard that there were concerns expressed earlier in the year about an image of the Anzac Memorial on our last cover and we would like to clarify that we did nothing to encourage the children to climb on it. We saw them there and snapped the picture. The photo is a true representation of something that happens in Onslow, and as such we reported it.
One of the key functions of journalism is operating as a âtown squareâ, where the opinions of different members of the community are aired. In this way a publication can help facilitate debate and understanding between different groups. We know that not everyone in Onslow agrees with each other, but we seek to allow everyone a space to speak through our pages.
Sometimes opinions are based on misunderstood facts and so some of the things people say may not be true. We canât vouch for the truth of what the people we spoke to said, but we have faithfully recorded it so that this edition is a true record of what was being said in and about Onslow in mid-late 2014.
We hope you enjoy reading it
Detection of atomic spin labels in a lipid bi-layer using a single-spin nanodiamond probe
Magnetic field fluctuations arising from fundamental spins are ubiquitous in
nanoscale biology, and are a rich source of information about the processes
that generate them. However, the ability to detect the few spins involved
without averaging over large ensembles has remained elusive. Here we
demonstrate the detection of gadolinium spin labels in an artificial cell
membrane under ambient conditions using a single-spin nanodiamond sensor.
Changes in the spin relaxation time of the sensor located in the lipid bilayer
were optically detected and found to be sensitive to near-individual proximal
gadolinium atomic labels. The detection of such small numbers of spins in a
model biological setting, with projected detection times of one second, opens a
new pathway for in-situ nanoscale detection of dynamical processes in biology.Comment: 16 pages, 4 figure
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