536 research outputs found
Design investigation of cylindrical structures other than honeycomb Final report, 1 Jun. - 30 Nov. 1965
Lightweight, double walled cylindrical structure design investigatio
Supplementary report to the final report of the coral reef expert group: S4. Model to inform the design of a Reef Integrated Monitoring and Reporting Program
[Extract] This project developed a model to inform coral reef monitoring and management under the Reef 2050 Integrated Monitoring and Reporting Program (RIMReP) and the Reef 2050 Long-Term Sustainability Plan (Reef 2050 Plan). The model combines spatial statistical analyses with a mechanistic understanding of coral community dynamics. The purpose of the model is to analyse coral status and trend, and to guide the design of a coral monitoring program that most effectively captures these dynamics in space and time. This model uses per cent cover of hard corals and benthic composition as key indicators of reef state. Input variables include environmental data (e.g. temperature, salinity, sediment covers) and disturbance history (e.g. tropical cyclones, bleaching, water quality and outbreaks of the crown-of-thorns starfish). The model is calibrated against 20 years of in situ coral monitoring data and remotely sensed observations (1996-2015). A dual classification of all Great Barrier Reef (Reef) reefs was established based on (i) their benthic community composition and (ii) their coral cover trajectory over the 1996-2015 period, as a potential tool to stratify the future reef monitoring design. Both classifications, along with model outputs of coral cover, are available as a set of spatial layers (0.01 degree resolution).An accessible copy of this report is not yet available from this repository, please contact [email protected] for more information
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Effects of a Mindfulness-Based Intervention on Distress, Weight Gain, and Glucose Control for Pregnant Low-Income Women: A Quasi-Experimental Trial Using the ORBIT Model.
BackgroundStress can lead to excessive weight gain. Mindfulness-based stress reduction that incorporates mindful eating shows promise for reducing stress, overeating, and improving glucose control. No interventions have tested mindfulness training with a focus on healthy eating and weight gain during pregnancy, a period of common excessive weight gain. Here, we test the effectiveness of such an intervention, the Mindful Moms Training (MMT), on perceived stress, eating behaviors, and gestational weight gain in a high-risk sample of low income women with overweight/obesity.MethodWe conducted a quasi-experimental study assigning 115 pregnant women to MMT for 8 weeks and comparing them to 105 sociodemographically and weight equivalent pregnant women receiving treatment as usual. Our main outcomes included weight gain (primary outcome), perceived stress, and depression.ResultsWomen in MMT showed significant reductions in perceived stress (β = - 0.16) and depressive symptoms (β = - 0.21) compared to the treatment as usual (TAU) control group. Consistent with national norms, the majority of women (68%) gained excessive weight according to Institute of Medicine weight-gain categories, regardless of group. Slightly more women in the MMT group gained below the recommendation. Among secondary outcomes, women in MMT reported increased physical activity (β = 0.26) and had lower glucose post-oral glucose tolerance test (β = - 0.23), being 66% less likely to have impaired glucose tolerance, compared to the TAU group.ConclusionA short-term intervention led to significant improvements in stress, and showed promise for preventing glucose intolerance. However, the majority of women gained excessive weight. A longer more intensive intervention may be needed for this high-risk population. Clinical Trials.gov #NCT01307683
Iterated Binomial Sums and their Associated Iterated Integrals
We consider finite iterated generalized harmonic sums weighted by the
binomial in numerators and denominators. A large class of these
functions emerges in the calculation of massive Feynman diagrams with local
operator insertions starting at 3-loop order in the coupling constant and
extends the classes of the nested harmonic, generalized harmonic and cyclotomic
sums. The binomially weighted sums are associated by the Mellin transform to
iterated integrals over square-root valued alphabets. The values of the sums
for and the iterated integrals at lead to new
constants, extending the set of special numbers given by the multiple zeta
values, the cyclotomic zeta values and special constants which emerge in the
limit of generalized harmonic sums. We develop
algorithms to obtain the Mellin representations of these sums in a systematic
way. They are of importance for the derivation of the asymptotic expansion of
these sums and their analytic continuation to . The
associated convolution relations are derived for real parameters and can
therefore be used in a wider context, as e.g. for multi-scale processes. We
also derive algorithms to transform iterated integrals over root-valued
alphabets into binomial sums. Using generating functions we study a few aspects
of infinite (inverse) binomial sums.Comment: 62 pages Latex, 1 style fil
The Ulysses fast latitude scans: COSPIN/KET results
International audienceUlysses, launched in October 1990, began its second out-of-ecliptic orbit in December 1997, and its second fast latitude scan in September 2000. In contrast to the first fast latitude scan in 1994/1995, during the second fast latitude scan solar activity was close to maximum. The solar magnetic field reversed its polarity around July 2000. While the first latitude scan mainly gave a snapshot of the spatial distribution of galactic cosmic rays, the second one is dominated by temporal variations. Solar particle increases are observed at all heliographic latitudes, including events that produce >250 MeV protons and 50 MeV electrons. Using observations from the University of Chicago's instrument on board IMP8 at Earth, we find that most solar particle events are observed at both high and low latitudes, indicating either acceleration of these particles over a broad latitude range or an efficient latitudinal transport. The latter is supported by "quiet time" variations in the MeV electron background, if interpreted as Jovian electrons. No latitudinal gradient was found for >106 MeV galactic cosmic ray protons, during the solar maximum fast latitude scan. The electron to proton ratio remains constant and has practically the same value as in the previous solar maximum. Both results indicate that drift is of minor importance. It was expected that, with the reversal of the solar magnetic field and in the declining phase of the solar cycle, this ratio should increase. This was, however, not observed, probably because the transition to the new magnetic cycle was not completely terminated within the heliosphere, as indicated by the Ulysses magnetic field and solar wind measurements. We argue that the new A<0-solar magnetic modulation epoch will establish itself once both polar coronal holes have developed
Species distribution models of tropical deep-sea snappers
Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and for predicting future distributions of deep-sea snappers.Céline Gomez, Ashley J. Williams, Simon J. Nicol, Camille Mellin, Kim L. Loeun, Corey J. A. Bradsha
Buoyant Venus station mission feasibility study for 1972 and 1973 launch opportunities. Volume 3 - Configuration definition. Part 2 - Appendixes Final report
Buoyant Venus station mission study for 1972 - 1973 launch period - backup data including atmospheric models, heat shield requirements, etc
Multi-scale marine biodiversity patterns inferred efficiently from habitat image processing
Cost-effective proxies of biodiversity and species abundance, applicable across a range of spatial scales, are needed for setting conservation priorities and planning action. We outline a rapid, efficient, and low-cost measure of spectral signal from digital habitat images that, being an effective proxy for habitat complexity, correlates with species diversity and requires little image processing or interpretation. We validated this method for coral reefs of the Great Barrier Reef (GBR), Australia, across a range of spatial scales (1 m to 10 km), using digital photographs of benthic communities at the transect scale and high-resolution Landsat satellite images at the reef scale. We calculated an index of image-derived spatial heterogeneity, the mean information gain (MIG), for each scale and related it to univariate (species richness and total abundance summed across species) and multivariate (species abundance matrix) measures of fish community structure, using two techniques that account for the hierarchical structure of the data: hierarchical (mixed-effect) linear models and distance-based partial redundancy analysis. Over the length and breadth of the GBR, MIG alone explained up to 29% of deviance in fish species richness, 33% in total fish abundance, and 25% in fish community structure at multiple scales, thus demonstrating the possibility of easily and rapidly exploiting spatial information contained in digital images to complement existing methods for inferring diversity and abundance patterns among fish communities. Thus, the spectral signal of unprocessed remotely sensed images provides an efficient and low-cost way to optimize the design of surveys used in conservation planning. In data-sparse situations, this simple approach also offers a viable method for rapid assessment of potential local biodiversity, particularly where there is little local capacity in terms of skills or resources for mounting in-depth biodiversity surveys.Camille Mellin, Lael Parrott, Serge Andréfouët, Corey J. A. Bradshaw, M. Aaron MacNeil, and M. Julian Cale
A Comprehensive View of the 2006 December 13 CME: From the Sun to Interplanetary Space
The biggest halo coronal mass ejection (CME) since the Halloween storm in
2003, which occurred on 2006 December 13, is studied in terms of its solar
source and heliospheric consequences. The CME is accompanied by an X3.4 flare,
EUV dimmings and coronal waves. It generated significant space weather effects
such as an interplanetary shock, radio bursts, major solar energetic particle
(SEP) events, and a magnetic cloud (MC) detected by a fleet of spacecraft
including STEREO, ACE, Wind and Ulysses. Reconstruction of the MC with the
Grad-Shafranov (GS) method yields an axis orientation oblique to the flare
ribbons. Observations of the SEP intensities and anisotropies show that the
particles can be trapped, deflected and reaccelerated by the large-scale
transient structures. The CME-driven shock is observed at both the Earth and
Ulysses when they are separated by 74 in latitude and 117
in longitude, the largest shock extent ever detected. The ejecta seems missed
at Ulysses. The shock arrival time at Ulysses is well predicted by an MHD model
which can propagate the 1 AU data outward. The CME/shock is tracked remarkably
well from the Sun all the way to Ulysses by coronagraph images, type II
frequency drift, in situ measurements and the MHD model. These results reveal a
technique which combines MHD propagation of the solar wind and type II
emissions to predict the shock arrival time at the Earth, a significant advance
for space weather forecasting especially when in situ data are available from
the Solar Orbiter and Sentinels.Comment: 26 pages, 10 figures. 2008, ApJ, in pres
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