958 resultados para MANU BIOSPHERE RESERVE
Resumo:
Terrestrial ecosystems, occupying more than 25% of the Earth's surface, can serve as
`biological valves' in regulating the anthropogenic emissions of atmospheric aerosol
particles and greenhouse gases (GHGs) as responses to their surrounding environments.
While the signicance of quantifying the exchange rates of GHGs and atmospheric
aerosol particles between the terrestrial biosphere and the atmosphere is
hardly questioned in many scientic elds, the progress in improving model predictability,
data interpretation or the combination of the two remains impeded by
the lack of precise framework elucidating their dynamic transport processes over a
wide range of spatiotemporal scales. The diculty in developing prognostic modeling
tools to quantify the source or sink strength of these atmospheric substances
can be further magnied by the fact that the climate system is also sensitive to the
feedback from terrestrial ecosystems forming the so-called `feedback cycle'. Hence,
the emergent need is to reduce uncertainties when assessing this complex and dynamic
feedback cycle that is necessary to support the decisions of mitigation and
adaptation policies associated with human activities (e.g., anthropogenic emission
controls and land use managements) under current and future climate regimes.
With the goal to improve the predictions for the biosphere-atmosphere exchange
of biologically active gases and atmospheric aerosol particles, the main focus of this
dissertation is on revising and up-scaling the biotic and abiotic transport processes
from leaf to canopy scales. The validity of previous modeling studies in determining
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the exchange rate of gases and particles is evaluated with detailed descriptions of their
limitations. Mechanistic-based modeling approaches along with empirical studies
across dierent scales are employed to rene the mathematical descriptions of surface
conductance responsible for gas and particle exchanges as commonly adopted by all
operational models. Specically, how variation in horizontal leaf area density within
the vegetated medium, leaf size and leaf microroughness impact the aerodynamic attributes
and thereby the ultrane particle collection eciency at the leaf/branch scale
is explored using wind tunnel experiments with interpretations by a porous media
model and a scaling analysis. A multi-layered and size-resolved second-order closure
model combined with particle
uxes and concentration measurements within and
above a forest is used to explore the particle transport processes within the canopy
sub-layer and the partitioning of particle deposition onto canopy medium and forest
oor. For gases, a modeling framework accounting for the leaf-level boundary layer
eects on the stomatal pathway for gas exchange is proposed and combined with sap
ux measurements in a wind tunnel to assess how leaf-level transpiration varies with
increasing wind speed. How exogenous environmental conditions and endogenous
soil-root-stem-leaf hydraulic and eco-physiological properties impact the above- and
below-ground water dynamics in the soil-plant system and shape plant responses
to droughts is assessed by a porous media model that accommodates the transient
water
ow within the plant vascular system and is coupled with the aforementioned
leaf-level gas exchange model and soil-root interaction model. It should be noted
that tackling all aspects of potential issues causing uncertainties in forecasting the
feedback cycle between terrestrial ecosystem and the climate is unrealistic in a single
dissertation but further research questions and opportunities based on the foundation
derived from this dissertation are also brie
y discussed.
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Marca tip. en port.
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Ocean acidification is receiving increasing attention because of its potential to affect marine ecosystems. Rare CO2 vents offer a unique opportunity to investigate the response of benthic ecosystems to acidification. However, the benthic habitats investigated so far are mainly found at very shallow water (less than or equal to 5 m depth) and therefore are not representative of the broad range of continental shelf habitats. Here, we show that a decrease from pH 8.1 to 7.9 observed in a CO2 vent system at 40 m depth leads to a dramatic shift in highly diverse and structurally complex habitats. Forests of the kelp Laminaria rodriguezii usually found at larger depths (greater than 65 m) replace the otherwise dominant habitats (i.e. coralligenous outcrops and rhodolith beds), which are mainly characterized by calcifying organisms. Only the aragonite-calcifying algae are able to survive in acidified waters, while high-magnesium-calcite organisms are almost completely absent. Although a long-term survey of the venting area would be necessary to fully understand the effects of the variability of pH and other carbonate parameters over the structure and functioning of the investigated mesophotic habitats, our results suggest that in addition of significant changes at species level, moderate ocean acidification may entail major shifts in the distribution and dominance of key benthic ecosystems at regional scale, which could have broad ecological and socio-economic implications.
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Humanity has emerged as a major force in the operation of the biosphere. The focus is shifting from the environment as externality to the biosphere as precondition for social justice, economic development, and sustainability. In this article, we exemplify the intertwined nature of social-ecological systems and emphasize that they operate within, and as embedded parts of the biosphere and as such coevolve with and depend on it. We regard social-ecological systems as complex adaptive systems and use a social-ecological resilience approach as a lens to address and understand their dynamics. We raise the challenge of stewardship of development in concert with the biosphere for people in diverse contexts and places as critical for long-term sustainability and dignity in human relations. Biosphere stewardship is essential, in the globalized world of interactions with the Earth system, to sustain and enhance our life-supporting environment for human well-being and future human development on Earth, hence, the need to reconnect development to the biosphere foundation and the need for a biosphere-based sustainability science.
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Penetration of fractional flow reserve (FFR) in clinical practice varies extensively, and the applicability of results from randomized trials is understudied. We describe the extent to which the information gained from routine FFR affects patient management strategy and clinical outcome. METHODS AND RESULTS: Nonselected patients undergoing coronary angiography, in which at least 1 lesion was interrogated by FFR, were prospectively enrolled in a multicenter registry. FFR-driven change in management strategy (medical therapy, revascularization, or additional stress imaging) was assessed per-lesion and per-patient, and the agreement between final and initial strategies was recorded. Cardiovascular death, myocardial infarction, or unplanned revascularization (MACE) at 1 year was recorded. A total of 1293 lesions were evaluated in 918 patients (mean FFR, 0.81±0.1). Management plan changed in 406 patients (44.2%) and 584 lesions (45.2%). One-year MACE was 6.9%; patients in whom all lesions were deferred had a lower MACE rate (5.3%) than those with at least 1 lesion revascularized (7.3%) or left untreated despite FFR≤0.80 (13.6%; log-rank P=0.014). At the lesion level, deferral of those with an FFR≤0.80 was associated with a 3.1-fold increase in the hazard of cardiovascular death/myocardial infarction/target lesion revascularization (P=0.012). Independent predictors of target lesion revascularization in the deferred lesions were proximal location of the lesion, B2/C type and FFR. CONCLUSIONS: Routine FFR assessment of coronary lesions safely changes management strategy in almost half of the cases. Also, it accurately identifies patients and lesions with a low likelihood of events, in which revascularization can be safely deferred, as opposed to those at high risk when ischemic lesions are left untreated, thus confirming results from randomized trials.
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The California sea otter population is gradually expanding in size and geographic range and is consequently invading new feeding grounds, including bays and estuaries that are home to extensive populations of bivalve prey. One such area is the Elkhorn Slough, where otters have apparently established a spring and summer communal feeding and resting area. In anticipation of future otter foraging in the slough, an extensive baseline database on bivalve densities, size distributions, biomasses, and burrow depths has been established for three potential bivalve prey species, Saxidomus nuttalli, Tresus nutallii, and Zirphaea pilsbryi. In 1986, the Elkhorn Slough otters were foraging predominately at two areas immediately east and west of the Highway 1 bridge (Skipper's and the PG&E Outfall). Extensive subtidal populations of Saxidomus nuttalli and Tresus nuttallii occur in these areas. Shell records collected at these study areas indicated that sea otters were foraging selectively on Saxidomus over Tresus. The reason for this apparent preference was not clear. At the Skipper's study site, 51% of the shell record was composed of Saxidomus, yet this species accounted for only 16% of the in situ biomass, and only 39% of the available clams. Tresus represented 49% of the shell record at Skipper's, yet this species accounted for 84% of the in situ biomass and 61% of the available clams. There was no difference in mean burrow depth between the two species at this site so availability does not explain the disparity in consumption. At the PG&E Outfall, Saxidomus represents 66% of the in situ biomass and 81% of the available clams, while Tresus accounts for 34% of the in situ biomass and 19% of the available clams. Saxidomus accounts for 96% of the shell record at this site vs. 4% for Tresus, again indicating that the otters were preying on Saxidomus out of proportion to their density or biomass. High densities and biomasses of a third species, Zirphaea pilsbryi, occur in areas where sea otters were observed to be foraging, yet no cast-off Zirphaea shells were found. Although it is possible this species was not represented in the shell record because the otters were simply chewing up the shells, it is more likely this species is avoided by sea otters. There were relatively few sea otters in the Elkhorn Slough in 1986 compared to the previous two years. This, coupled with high bivalve densities, precluded any quantitative comparison of bivalve densities before and after the 1986 sea otter occupation. Qualitative observations made during the course of this study, and quantitative observations from previous studies indicate that, after 3 years, sea otters are not yet significantly affecting bivalve densities in the Elkhorn Slough.
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"*GPO:2008--339-126/80035."
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Introduction: Few data is available about the hydration status of active adolescents in free living conditions. Cell dehydration may be prevalent in healthy, free-living children at school and they could be in a state of chronic voluntary dehydration. Objective: This study aims to describe hydration status assessed by Free Water Reserve (FWR) in adolescents. Method: Two hundred participants (118 girls), aged 13-18 years completed the study. Urinary volume (ml/d) and urinary osmolality (mosm/kg) were measured by one 24h urinary collection, and coefficient of creatinine was used to validate completeness of urine collections. FWR (measured urine volume minus the obligatory urine volume) was used for characterization of hydration status. Positive values of FWR indicate euhydration, negative values the risk of hypo-hydration. Results: Median urinary volume excretion was 1100.0 ml/d for boys and 1025.0 ml/d for girls (p=0.923). Mean urinary osmolality was 715.7±172.3 mosm/kg for boys and 597.42±193.1 mosm/kg for girls (p=0.247). Median FWR (ml/24h) was positive in both sex groups (173.2 ml/d in boys and 373.2 ml/d in girls); however, 40.2% of boys and 31.4% of girls (p=0.195) were at risk of hypo-hydration status. Conclusions: In this sample of adolescents approximately one third was classified as at risk of hypo-hydration status. Preventive measures to increase the level of total water intake should be considered.
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The purpose of this project is to develop a three-dimensional block model for a garnet deposit in the Alder Gulch, Madison County, Montana. Garnets occur in pre-Cambrian metamorphic Red Wash gneiss and similar rocks in the vicinity. This project seeks to model the percentage of garnet in a deposit called the Section 25 deposit using the Surpac software. Data available for this work are drillhole, trench and grab sample data obtained from previous exploration of the deposit. The creation of the block model involves validating the data, creating composites of assayed garnet percentages and conducting basic statistics on composites using Surpac statistical tools. Variogram analysis will be conducted on composites to quantify the continuity of the garnet mineralization. A three-dimensional block model will be created and filled with estimates of garnet percentage using different methods of reserve estimation and the results compared.
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Marca tip. en port. y en x7v (Edit 16, U59)
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The primary aim of this study was to compare rating of perceived exertion (RPE) values measuring repetitions in reserve (RIR) at particular intensities of 1 repetition maximum (RM) in experienced (ES) and novice squatters (NS). Furthermore, this investigation compared average velocity between ES and NS at the same intensities. Twenty-nine individuals (24.0 ± 3.4 years) performed a 1RM squat followed by a single repetition with loads corresponding to 60, 75, and 90% of 1RM and an 8-repetition set at 70% 1RM. Average velocity was recorded at 60, 75, and 90% 1RM and on the first and last repetitions of the 8-repetition set. Subjects reported an RPE value that corresponded to an RIR value (RPE-10 = 0-RIR, RPE-9 = 1-RIR, and so forth). Subjects were assigned to one of the 2 groups: (a) ES (n = 15, training age: 5.2 ± 3.5 years) and (b) NS (n = 14, training age: 0.4 ± 0.6 years). The mean of the average velocities for ES was slower (p ≤ 0.05) than NS at 100% and 90% 1RM. However, there were no differences (p > 0.05) between groups at 60, 75%, or for the first and eighth repetitions at 70% 1RM. In addition, ES recorded greater RPE at 1RM than NS (p = 0.023). In ES, there was a strong inverse relationship between average velocity and RPE at all percentages (r = −0.88, p < 0.001), and a strong inverse correlation in NS between average velocity and RPE at all intensities (r = −0.77, p = 0.001). Our findings demonstrate an inverse relationship between average velocity and RPE/RIR. Experienced squatter group exhibited slower average velocity and higher RPE at 1RM than NS, signaling greater efficiency at high intensities. The RIR-based RPE scale is a practical method to regulate daily training load and provide feedback during a 1RM test.
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This activity book is a fun way to reinforce and enrich every student’s ACE Basin experience ... to instill a stronger awareness and respect for environmentalism and conservation, to broaden their knowledge of this area where they co-exist with a diversity of other life forms, and to encourage them to enjoy the adventure and discovery within Coastal South Carolina. These pages can also be used as coloring pages.
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Studies that combine both the ecological responses of marine species and protection measures with movement patterns and habitat use are of major importance in order to better understand the performance of marine protected areas (MPA) and how species respond to their implementation. However, few studies have assessed MPA performance by relating local individual movement patterns and the observed reserve effects. In this study, we combined acoustic telemetry with abundance estimates to study the early effects of a recently established small coastal MPA on the local populations of white seabream. The results show that even small, recently established coastal MPAs can increase the abundance and biomass of commercial fish species, provided that target species have small home ranges and exhibit high site fidelity.