2,438 research outputs found
Mafic alkaline metasomatism in the lithosphere underneath East Serbia: evidence from the study of xenoliths and the host alkali basalts
Effects of mafic alkaline metasomatism have been investigated by a combined study of the East Serbian mantle xenoliths and their host alkaline rocks. Fertile xenoliths and tiny mineral assemblages found in depleted xenoliths have been investigated. Fertile lithologies are represented by clinopyroxene (cpx)-rich lherzolite and spinel (sp)-rich olivine websterite containing Ti–Al-rich Cr-augite, Fe-rich olivine, Fe–Al-rich orthopyroxene and Al-rich spinel. Depleted xenoliths, which are the predominant lithology in the suite of East Serbian xenoliths, are harzburgite, cpx-poor lherzolite and rare Mg-rich dunite. They contain small-scale assemblages occurring as pocket-like, symplectitic or irregular, deformation-assisted accumulations of metasomatic phases, generally composed of Ti–Al- and incompatible element-rich Cr-diopside, Cr–Fe–Ti-rich spinel, altered glass, olivine, apatite, ilmenite, carbonate, feldspar, and a high-TiO2 (c. 11 wt%) phlogopite. The fertile xenoliths are too rich in Al, Ca and Fe to simply represent undepleted mantle. By contrast, their composition can be reproduced by the addition of 5–20 wt% of a basanitic melt to refractory mantle. However, textural relationships found in tiny mineral assemblages inside depleted xenoliths imply the following reaction: opx+sp1 (primary mantle Cr-spinel) ±phlogopite+Si-poor alkaline melt=Ti–Al-cpx+sp2 (metasomatic Ti-rich spinel)±ol±other minor phases. Inversion modelling, performed on the least contaminated and most isotopically uniform host basanites (87Sr/86Sr=c. 0.7031; 143Nd/144Nd=c. 0.5129), implies a source that was enriched in highly and moderately incompatible elements (c. 35–40× chondrite for U–Th–Nb–Ta, 2× chondrite for heavy rare earth elements (HREE), made up of clinopyroxene, carbonate (c. 5%), and traces of ilmenite (c. 1%) and apatite (c. 0.05%). A schematic model involves: first, percolation of CO2- and H2O-rich fluids and precipitation of metasomatic hydrous minerals; and, second, the subsequent breakdown of these hydrous minerals due to the further uplift of hot asthenospheric mantle. This model links intraplate alkaline magmatism to lithospheric mantle sources enriched by sublithospheric melts at some time in the past
WEFES - Web explorer of forest ecosystems services under climate change
PosterClimate change will change the dynamics of forest environmental services. All the change complexity involved is difficult to visualize under an easy and accessible information tool capable to integrate several services that forests can provide.
A preliminary Web-Explorer of Forest Ecosystems Services was developed for New Zealand where forest managers and the general public can observe what are the predictions of the different forest environmental services under current and future climate for each location in the territory. Carbon storage, soil erosion, biodiversity, nitrate leaching, water balance are the preliminary forest environmental services envisaged.
The tool uses a mix of programming languages and techniques (HTML, Javascript, PHP, and Ajax) as well as the GoogleMaps© application programming interface to interact with New Zealand online-stored geographical information to supply different models´ needs. A score system is calculated for the user reference where tradeoffs can be observed by changing the climate variables in the models.
The tool (see link below) is under development and expecting “expressions of interest” for further improvement but already enabled a good interaction between different scientific background as well as interest from private forest organizations.
Tool link: http://home.isa.utl.pt/~joaopalma/projects/tranzfor/wefesTRANZFOR - SCION - ISA/UTL - MORST - FFR - FCT/MCTE
Learning with multiple representations: An example of a revision lesson in mechanics
We describe an example of learning with multiple representations in an
A-level revision lesson on mechanics. The context of the problem involved the
motion of a ball thrown vertically upwards in air and studying how the
associated physical quantities changed during its flight. Different groups of
students were assigned to look at the ball's motion using various
representations: motion diagrams, vector diagrams, free-body diagrams, verbal
description, equations and graphs, drawn against time as well as against
displacement. Overall, feedback from students about the lesson was positive. We
further discuss the benefits of using computer simulation to support and extend
student learning.Comment: 10 pages, 5 figures, 2 tables http://iopscience.iop.org/0031-912
Analysis and Modeling of Two Flare Loops Observed by AIA and EIS
We analyze and model an M1.0 flare observed by SDO/AIA and Hinode/EIS to
investigate how flare loops are heated and evolve subsequently. The flare is
composed of two distinctive loop systems observed in EUV images. The UV 1600
\AA emission at the feet of these loops exhibits a rapid rise, followed by
enhanced emission in different EUV channels observed by AIA and EIS. Such
behavior is indicative of impulsive energy deposit and the subsequent response
in overlying coronal loops that evolve through different temperatures. Using
the method we recently developed, we infer empirical heating functions from the
rapid rise of the UV light curves for the two loop systems, respectively,
treating them as two big loops of cross-sectional area 5\arcsec by 5\arcsec,
and compute the plasma evolution in the loops using the EBTEL model (Klimchuk
et al. 2008). We compute the synthetic EUV light curves, which, with the
limitation of the model, reasonably agree with observed light curves obtained
in multiple AIA channels and EIS lines: they show the same evolution trend and
their magnitudes are comparable by within a factor of two. Furthermore, we also
compare the computed mean enthalpy flow velocity with the Doppler shift
measurements by EIS during the decay phase of the two loops. Our results
suggest that the two different loops with different heating functions as
inferred from their footpoint UV emission, combined with their different
lengths as measured from imaging observations, give rise to different coronal
plasma evolution patterns captured both in the model and observations.Comment: Accepted for publication in Ap
Supergravity loop contributions to brane world supersymmetry breaking
We compute the supergravity loop contributions to the visible sector scalar
masses in the simplest 5D `brane-world' model. Supersymmetry is assumed to be
broken away from the visible brane and the contributions are UV finite due to
5D locality. We perform the calculation with N = 1 supergraphs, using a
formulation of 5D supergravity in terms of N = 1 superfields. We compute
contributions to the 4D effective action that determine the visible scalar
masses, and we find that the mass-squared terms are negative.Comment: 12 pages, LaTeX 2
Integrating the promotion of physical activity within a smoking cessation programme: Findings from collaborative action research in UK Stop Smoking Services
Background: Within the framework of collaborative action research, the aim was to explore the feasibility of
developing and embedding physical activity promotion as a smoking cessation aid within UK 6/7-week National
Health Service (NHS) Stop Smoking Services.
Methods: In Phase 1 three initial cycles of collaborative action research (observation, reflection, planning,
implementation and re-evaluation), in an urban Stop Smoking Service, led to the development of an integrated
intervention in which physical activity was promoted as a cessation aid, with the support of a theoretically based
self-help guide, and self monitoring using pedometers. In Phase 2 advisors underwent training and offered the
intervention, and changes in physical activity promoting behaviour and beliefs were monitored. Also, changes in
clients’ stage of readiness to use physical activity as a cessation aid, physical activity beliefs and behaviour and
physical activity levels were assessed, among those who attended the clinic at 4-week post-quit. Qualitative data
were collected, in the form of clinic observation, informal interviews with advisors and field notes.
Results: The integrated intervention emerged through cycles of collaboration as something quite different to
previous practice. Based on field notes, there were many positive elements associated with the integrated
intervention in Phase 2. Self-reported advisors’ physical activity promoting behaviour increased as a result of
training and adapting to the intervention. There was a significant advancement in clients’ stage of readiness to use physical activity as a smoking cessation aid.
Conclusions: Collaboration with advisors was key in ensuring that a feasible intervention was developed as an aid to smoking cessation. There is scope to further develop tailored support to increasing physical activity and
smoking cessation, mediated through changes in perceptions about the benefits of, and confidence to do physical activity
Economic evaluation of a task-shifting intervention for common mental disorders in India
OBJECTIVE: To carry out an economic evaluation of a task-shifting intervention for the treatment of depressive and anxiety disorders in primary-care settings in Goa, India. METHODS: Cost-utility and cost-effectiveness analyses based on generalized linear models were performed within a trial set in 24 public and private primary-care facilities. Subjects were randomly assigned to an intervention or a control arm. Eligible subjects in the intervention arm were given psycho-education, case management, interpersonal psychotherapy and/or antidepressants by lay health workers. Subjects in the control arm were treated by physicians. The use of health-care resources, the disability of each subject and degree of psychiatric morbidity, as measured by the Revised Clinical Interview Schedule, were determined at 2, 6 and 12 months. FINDINGS: Complete data, from all three follow-ups, were collected from 1243 (75.4%) and 938 (81.7%) of the subjects enrolled in the study facilities from the public and private sectors, respectively. Within the public facilities, subjects in the intervention arm showed greater improvement in all the health outcomes investigated than those in the control arm. Time costs were also significantly lower in the intervention arm than in the control arm, whereas health system costs in the two arms were similar. Within the private facilities, however, the effectiveness and costs recorded in the two arms were similar. CONCLUSION: Within public primary-care facilities in Goa, the use of lay health workers in the care of subjects with common mental disorders was not only cost-effective but also cost-saving
In Their Own Words: Student Mental Health in Rural, Low Socioeconomic High Schools
The purpose of this research paper was to highlight the factors students and school staff identify as contributors to mental health issues students attending rural, low socioeconomic high schools experience and the specific mental health issues they witness most. A collective case study was conducted in four rural high schools, two in Kansas and two in West Virginia. Field work at each school involved observations, document collection, and semi-structured focus group interviews with students and school staff. The factors identified as contributors to poor student mental health were pressure, technology, home life, bullying, and stigma. Anxiety, stress, depression, lack of health coping, and suicidal comments emerged as the specific mental health struggles students deal with the most. Recommendations for practice include practical ways to address the identified contributors of poor student mental health in rural schools and strategies to normalize mental health in the rural school environment
Technical and Economic Evaluation of Macroalgae Cultivation for Fuel Production (Draft)
The potential of macroalgae as sources of renewable liquid and gaseous fuels is evaluated. A series of options for production of macroalgae feedstock is considered. Because of their high carbohydrate content, the fuel products for which macroalgae are most suitable are methane and ethanol. Fuel product costs were compared with projected fuel costs in the year 1995
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