526 research outputs found
The Effect of Increasing Aboriginal Educational Attainment on the Labour Force, Output and the Fiscal Balance
Investing in disadvantaged young people is one of the rare public policies with no equity-efficiency tradeoff. Based on the methodology developed in Sharpe, Arsenault and Lapointe (2007), we estimate the effect of increasing the educational attainment level of Aboriginal Canadians on labour market outcome and output up to 2026. We build on these projection to estimate the potential effect of eliminating educational and social gaps between Aboriginal and non-Aboriginal people on government spending and government revenues using population and economic projections to 2026.Aboriginal, Education, Canada, Forecast of economic growth, Equity and efficiency.
Ecology and Life History of the Raccoon (Procyon lotor hirtus Nelson and Goldman) in the Northern Part of its Range
A study of the ecology and life history of the northern raccoon Procyon lotor hirtus Nelson and Goldman, 193C) was conducted ir. southwestern Manitoba between June, 1967, and August, 1969. Information concerning growth, development, reproduction and population characteristics was gathered from carcasses of 293 raccoons of juvenile, yearling, and adult age. Seasonal activities and home ranges were determined by marking 81 mobile raccoons and 13 nestlings, and by recaptures of 27 of these. Movements of 11 raccoons were monitored electronically, A total 1,109 scats and 298 stomachs and colons were analyzed for food content and to determine seasonal requirements of nutrition. Eighty-six dens were investigated to determine seasonal needs for protection. Body weights were compared with ages of 351 raccoons collected at various seasons, and with winter mortality. Winter denning activities were compared with ambient temperatures and with den quality to determine the effects of the winter environment on survival. Recent changes in the ecology of the aspen parklands, mortality factors, and limiting factors were investigated to determine the present status of raccoons in the northern part of their range.
Three age classes of raccoons were described, based on eye lens weight. Juveniles became yearlings at nine months when eye lens weight was 85 mg. Yearlings became adults at 15 months, when eye lens weight was 114 mg. Mating took place from late February to June, with the peak in activity in March; the peak of parturition occurred in May. However, 13.6 of the yearlings and 36.5 and 4 over winter and yearling mortality rate was high, possibly 60. Mean life span was 1.3 years and turnover rate was 7.4 years.
The major limiting environmental factors were lack of food and denning sites in winter. These have been replaced in large part by stored grain, vacant farmsteads, and scrub p51es which have greatly increased in number since the 1940s, due to changes in agriculture and economic policies. Raccoons have become established in Manitoba and are presently increasing in the northern part of the aspen parklands
Effect of hydrocarbon presence and properties on the magnetic signature of the reservoir sediments of the Catcher Area Development (CAD) region, UK North Sea
This paper presents a detailed study investigating the effect of hydrocarbon presence on magnetic mineral diagenesis in sediments from the Catcher Area Development (CAD) region, UK North Sea, between 1,000 and 1,500 m (True Vertical Depth Sub-Sea). Magnetic analysis of core samples from hydrocarbon fields of the region and nearby dry-well sandstones (background) was carried out to determine if their signatures can serve as a proxy for understanding petroleum reservoir systems. From the background samples, nanometric and micron-sized magnetite, hematite and titano-iron oxides, were identified. Hydrocarbon presence in the reservoir sediments was found to diminish the iron-oxide signature and favour the precipitation of hexagonal pyrrhotite, siderite and potentially vivianite, lepidocrocite, greigite and paramagnetic iron sulphides. Hexagonal pyrrhotite was found at the oil-water transition zones. This relationship is possibly related to biodegradation at this interface. Siderite was found in increased abundance at shallower depths within the reservoir, which we attribute to hydrocarbon vertical migration and biodegradation. The interbedded shales also experienced significant magnetic mineral diagenesis that depended on its proximity to the hydrocarbon plume. These findings suggest that mineral magnetism can be applied to the identification of oil-water transition zones, reserve estimation, production planning and the determination of hydrocarbon migration pathways. It also suggests that mineral magnetic methods can be used to estimate the timing of hydrocarbon migration
Observation and simulation of solid sedimentary flux: examples from northwest Africa
The sedimentary archive preserved at passive margins provides important clues about the evolution of continental topography. For example, histories of African uplift, erosion, and deposition of clastic sedimentary rock provide information about mantle convection. Furthermore, relating histories of uplift and erosion from regions where sediment is generated to measurements of efflux is important for understanding basin evolution and the distribution of natural resources. We focus on constraining Mesozoic to Recent solid sedimentary flux to northwest Africa's passive margin, which today is fed by rivers draining dynamically supported topography. Histories of sedimentary flux are calculated by mapping stratigraphy using seismic reflection and well data courtesy of Tullow Oil Plc and TGS. Stratigraphic ages, conversion from two‐way time to depth and compaction, are parameterized using biostratigraphic and check‐shot records from exploration, International Ocean Discovery Program and Deep Sea Drilling Project wells. Results indicate that Late Cretaceous to Oligocene (∼100–23 Ma) sedimentary flux decreased gradually. A slight increase in Neogene sedimentary flux is observed, which is concomitant with a change from carbonate to clastic sedimentation. Pliocene to Recent (∼5–0 Ma) flux increased by an order of magnitude. This history of sedimentary flux and facies change is similar to histories observed at other African deltas. To constrain sources of sedimentary flux, 14,700 longitudinal river profiles were inverted to calculate a history of continental uplift. These results were used to parameterize a simple “source‐to‐sink” model of fluvial erosion and sedimentary efflux. Results suggest that increased clastic flux to Africa's deltas from ∼30 Ma was driven by denudation induced by dynamic support
Observation and Simulation of Solid Sedimentary Flux: Examples From Northwest Africa
The sedimentary archive preserved at passive margins provides important clues about the evolution of continental topography. For example, histories of African uplift, erosion, and deposition of clastic sedimentary rock provide information about mantle convection. Furthermore, relating histories of uplift and erosion from regions where sediment is generated to measurements of efflux is important for understanding basin evolution and the distribution of natural resources. We focus on constraining Mesozoic to Recent solid sedimentary flux to northwest Africa's passive margin, which today is fed by rivers draining dynamically supported topography. Histories of sedimentary flux are calculated by mapping stratigraphy using seismic reflection and well data courtesy of Tullow Oil Plc and TGS. Stratigraphic ages, conversion from two-way time to depth and compaction, are parameterized using biostratigraphic and check-shot records from exploration, International Ocean Discovery Program and Deep Sea Drilling Project wells. Results indicate that Late Cretaceous to Oligocene (∼100–23 Ma) sedimentary flux decreased gradually. A slight increase in Neogene sedimentary flux is observed, which is concomitant with a change from carbonate to clastic sedimentation. Pliocene to Recent (∼5–0 Ma) flux increased by an order of magnitude. This history of sedimentary flux and facies change is similar to histories observed at other African deltas. To constrain sources of sedimentary flux, 14,700 longitudinal river profiles were inverted to calculate a history of continental uplift. These results were used to parameterize a simple “source-to-sink” model of fluvial erosion and sedimentary efflux. Results suggest that increased clastic flux to Africa's deltas from ∼30 Ma was driven by denudation induced by dynamic support
Germ cell differentiation in the marmoset (Callithrix jacchus) during fetal and neonatal life closely parallels that in the human
Gliese 581g as a scaled-up version of Earth: atmospheric circulation simulations
We use three-dimensional simulations to study the atmospheric circulation on
the first Earth-sized exoplanet discovered in the habitable zone of an M star.
We treat Gliese 581g as a scaled-up version of Earth by considering increased
values for the exoplanetary radius and surface gravity, while retaining
terrestrial values for parameters which are unconstrained by current
observations. We examine the long-term, global temperature and wind maps near
the surface of the exoplanet --- the climate. The specific locations for
habitability on Gliese 581g depend on whether the exoplanet is tidally-locked
and how fast radiative cooling occurs on a global scale. Independent of whether
the existence of Gliese 581g is confirmed, our study highlights the use of
general circulation models to quantify the atmospheric circulation on
potentially habitable, Earth-sized exoplanets, which will be the prime targets
of exoplanet discovery and characterization campaigns in the next decade.Comment: Accepted by MNRAS. 15 pages, 13 figures. Sample movies of simulations
are available at http://www.phys.ethz.ch/~kheng/fms
A novel method for the isolation of subpopulations of rat adipose stem cells with different proliferation and osteogenic differentiation potentials
Bone marrow has been the elected cell source of studies published so far concerning bone and cartilage tissue-engineering approaches. Recent studies indicate that adipose tissue presents significant advantages over bone marrow as a cell source for tissue engineering. Most of these
studies report the use of adipose stem cells (ASCs) isolated by a method based on the enzymatic digestion of the adipose tissue and on the ability of stem cells to adhere to a cell culture plastic surface. Using this method, a heterogeneous population was obtained containing different cell types that have been shown to compromise the proliferation and differentiation potential of the
stem cells. This paper reports the development and optimization of a new isolation method that
enables purified cell populations to be obtained that exhibit higher osteogenic differentiation
and/or proliferation potential. This method is based on the use of immunomagnetic beads coated
with specific antibodies and it is compared with other methods described in the literature for
the selection of stem cell populations, e.g. methods based on a gradient solution and enzymatic
digestion. The results showed that the isolation method based on immunomagnetic beads allows
distinct subpopulations of rat ASCs to be isolated, showing different stem cells marker expressions
and different osteogenic differentiation potentials. Therefore, this method can be used to study
niches in ASC populations and/or also allow adipose tissue to be used as a stem cell source in a more efficient manner, increasing the potential of this cell source in future clinical applications.T. Rada thanks the EU Marie Curie Actions Alea Jacta Est for a PhD fellowship. This work was partially supported by the European Union-funded STREP Project HIPPOCRATES (Grant
No. NMP3-CT-2003-505758) and was carried out under the scope of the European NoE EXPERTISSUES (Grant No. NMP3-CT-2004-500283)
Recommended from our members
Was the cold European winter 2009-2010 modified by anthropogenic climate change? An attribution study
An attribution study has been performed to investigate the degree to which the unusually cold European winter 2009-2010 was modified by anthropogenic climate change. Two different methods have been included for the attribution: one based on a large HadGEM3-A ensemble and one based on a statistical surrogate method. Both methods are evaluated by comparing simulated winter temperature means, trends, standard deviations, skewness, return periods, and 5 % quantiles with observations. While the surrogate method performs well, HadGEM3-A in general underestimates the trend in winter by a factor of 2/3. It has a mean cold bias dominated by the mountainous regions and also underestimates the cold 5 % quantile in many regions of Europe. Both methods show that the probability of experiencing a winter as cold as 2009-2010 has been reduced by approximately a factor of two due to anthropogenic changes. The method based on HadGEM3-A ensembles gives somewhat larger changes than the surrogate method because of differences in the definition of the unperturbed climate. The results are based on two diagnostics: the coldest day in winter and the largest continuous area with temperatures colder than twice the local standard deviation. The results are not sensitive to the choice of bias correction except in the mountainous regions. Previous results regarding the behavior of the measures of the changed probability have been extended. The counter-intuitive behavior for heavy-tailed distributions is found to hold for a range of measures and for events that become more rare in a changed climate
- …