749 research outputs found
Some NASA contributions to human factors engineering: A survey
This survey presents the NASA contributions to the state of the art of human factors engineering, and indicates that these contributions have a variety of applications to nonaerospace activities. Emphasis is placed on contributions relative to man's sensory, motor, decisionmaking, and cognitive behavior and on applications that advance human factors technology
Carrier-induced ferromagnetism in n-type ZnMnAlO and ZnCoAlO thin films at room temperature
The realization of semiconductors that are ferromagnetic above room
temperature will potentially lead to a new generation of spintronic devices
with revolutionary electrical and optical properties. Transition temperatures
in doped ZnO are high but, particularly for Mn doping, the reported moments
have been small. We show that by careful control of both oxygen deficiency and
aluminium doping the ferromagnetic moments measured at room temperature in
n-type ZnMnO and ZnCoO are close to the ideal values of 5mB and 3mB
respectively. Furthermore a clear correlation between the magnetisation per
transition metal ion and the ratio of the number of carriers to the number of
transition metal donors was established as is expected for carrier induced
ferromagnetism for both the Mn and Co doped films. The dependence of the
magnetisation on carrier density is similar to that predicted for the
transition temperature for a dilute magnetic semiconductor in which the
exchange between the transition metal ions is through the free carriers.Comment: 14 pages pd
Using the Community of Practice model to shape approaches to Education for Sustainable Development across disciplines in a Technological University context: A Roundtable Podcast
This roundtable discussion podcast comprises eight colleagues engaged in reflective discussion of their shared experiences of being members of SDG Literacy.ie, a Community of Practice (CoP) first established in TU Dublin in 2020. This CoP focuses on and promotes the enhancement of Sustainability Literacy among student cohorts as one measure to be employed in strengthening Education for Sustainable Development (ESD) in line with the broader strategic aims of the university. Harvey et al. (2021) in a case-based paper which includes examination of the CoP discussed here conclude that teaching and learning innovation took place as a consequence of the resource-sharing, idea-generation and overall peer support that CoP members experience. The voices you will hear in this podcast discussion represent the inter-disciplinary SDG Literacy academic community who all share an interest in the sustainability domain and are acutely aware of SDG4.7 which focuses on ensuring all learners acquire the knowledge and skills for sustainable development by 2030. Discussion themes include (i) our shared understanding of ESD, (ii) how membership of SDGLiteracy.ie shaped our Teaching, Learning and Assessment (TLA) approaches in relation to ESD, Sustainability Literacy and Authentic Assessment, (iii) how membership of SDGLiteracy.ie shaped our broader personal and professional development (research, collaboration, output etc.) and (iv) our future plans in relation to ESD and the CoP model. The podcast transcript has been annotated through footnotes to direct the listener/reader to further reading on the various topics that emerge in the discussion
Do PGI integrated farms perform better? The case of the beef farms in Spain
European rural development policy is gaining in importance through one of its key instruments, the Protected Geographical Indications (PGI) system, which is designed to improve quality standards. Previous research has shown that PGI-certified beef farms tend to be more extensively managed operations that are better adapted to mountainous areas. This paper describes a comparative study of two production systems, one with PGI certification and one without, focusing on a number of economic variables. The results show a positive association between PGI production and profitability. In efficiency terms, non-certified farms show better pure technical efficiency scores, while PGI-certified holdings score higher on scale efficiency
Room temperature magneto-optics of ferromagnetic transition-metal doped ZnO thin films
Magneto-optic studies of ZnO doped with transition metals Co, Mn, V and Ti
indicate a significant magnetic circular dichroism (MCD) at the ZnO band edge
at room temperature, together with an associated dispersive Faraday rotation.
Similar spectra occur for each dopant which implies that the ferromagnetism is
an intrinsic property of the bulk ZnO lattice. At 10 K additional paramagnetic
contributions to the MCD are observed, but above about 150K, the magnitude of
the MCD signal is dominated by the ferromagnetism and is almost temperature
independent. The MCD at the ZnO band edge shows room temperature hysteretic
behaviour.Comment: 4 page
Tropical Herbivorous Phasmids, but Not Litter Snails, Alter Decomposition Rates By Modifying Litter Bacteria
Consumers can alter decomposition rates through both feces and selective feeding in many ecosystems, but these combined effects have seldom been examined in tropical ecosystems. Members of the detrital food web (litter-feeders or microbivores) should presumably have greater effects on decomposition than herbivores, members of the green food web. Using litterbag experiments within a field enclosure experiment, we determined the relative effects of common litter snails (Megalomastoma croceum) and herbivorous walking sticks (Lamponius portoricensis) on litter composition, decomposition rates, and microbes in a Puerto Rican rainforest, and whether consumer effects were altered by canopy cover presence. Although canopy presence did not alter consumers’ effects, focal organisms had unexpected influences on decomposition. Decomposition was not altered by litter snails, but herbivorous walking sticks reduced leaf decomposition by about 50% through reductions in high quality litter abundance and, consequently, lower bacterial richness and abundance. This relatively unexplored but potentially important link between tropical herbivores, detritus, and litter microbes in this forest demonstrates the need to consider autotrophic influences when examining rainforest ecosystem processes
A gene signature for post-infectious chronic fatigue syndrome
Background: At present, there are no clinically reliable disease markers for chronic fatigue syndrome. DNA chip microarray technology provides a method for examining the differential expression of mRNA from a large number of genes. Our hypothesis was that a gene expression signature, generated by microarray assays, could help identify genes which are dysregulated in patients with post-infectious CFS and so help identify biomarkers for the condition. Methods: Human genome-wide Affymetrix GeneChip arrays (39,000 transcripts derived from 33,000 gene sequences) were used to compare the levels of gene expression in the peripheral blood mononuclear cells of male patients with post-infectious chronic fatigue (n = 8) and male healthy control subjects (n = 7). Results: Patients and healthy subjects differed significantly in the level of expression of 366 genes. Analysis of the differentially expressed genes indicated functional implications in immune modulation, oxidative stress and apoptosis. Prototype biomarkers were identified on the basis of differential levels of gene expression and possible biological significance Conclusion: Differential expression of key genes identified in this study offer an insight into the possible mechanism of chronic fatigue following infection. The representative biomarkers identified in this research appear promising as potential biomarkers for diagnosis and treatment
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