Transforming provincial politics Evans, Bryan M; Smith, Charles W
Transforming provincial politics,
2014., 20150317, 2015, 2015-03-17, 2015-03-27, Letnik:
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eBook
Over the past thirty-five years, Canada's provinces and territories have undergone significant political changes. Abandoning mid-century Keynesian policies, governments of all political persuasions ...have turned to deregulation, tax reduction, and government downsizing as policy solutions for a wide range of social and economic issues.Transforming Provincial Politicsis the first province-by-province analysis of politics and political economy in more than a decade, and the first to directly examine the turn to neoliberal policies at the provincial and territorial level.
Featuring chapters written by experts in the politics of each province and territory,Transforming Provincial Politicsexamines how neoliberal policies have affected politics in each jurisdiction. A comprehensive and accessible analysis of the issues involved, this collection will be welcomed by scholars, instructors, and anyone interested in the state of provincial politics today.
Terrestrial ecosystems often vary dramatically in their responses to drought, but the reasons for this are unclear. With climate change forecasts for more frequent and extensive drought in the ...future, a more complete understanding of the mechanisms that determine differential ecosystem sensitivity to drought is needed. In 2012, the Central US experienced the fourth largest drought in a century, with a regional-scale 40 % reduction in growing season precipitation affecting ecosystems ranging from desert grassland to mesic tallgrass prairie. This provided an opportunity to assess ecosystem sensitivity to a drought of common magnitude in six native grasslands. We tested the prediction that drought sensitivity is inversely related to mean annual precipitation (MAP) by quantifying reductions in aboveground net primary production (ANPP). Long-term ANPP data available for each site (mean length = 16 years) were used as a baseline for calculating reductions in ANPP, and drought sensitivity was estimated as the reduction in ANPP per millimeter reduction in precipitation. Arid grasslands were the most sensitive to drought, but drought responses and sensitivity varied by more than twofold among the six grasslands, despite all sites experiencing 40 % reductions in growing season precipitation. Although drought sensitivity generally decreased with increasing MAP as predicted, there was evidence that the identity and traits of the dominant species, as well as plant functional diversity, influenced sensitivity. A more comprehensive understanding of the mechanisms leading to differences in drought sensitivity will require multi-site manipulative experiments designed to assess both biotic and abiotic determinants of ecosystem sensitivity.
We use observations from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, in orbit around Mercury, to investigate interplanetary coronal mass ejections ...(ICMEs) near 0.3 AU. MESSENGER is the first spacecraft since Helios 1 and 2 in the 1980s to make in situ measurements of the interplanetary medium at heliocentric distances < 0.5 AU. As such, it presents a unique opportunity for observing the innermost heliosphere. It also allows for observations of ICMEs well within 1 AU to study their evolution as they expand and propagate outward, interacting with the solar wind. We catalog ICME events observed by the MESSENGER Magnetometer between 2011 and 2014 and present statistical analyses of ICME properties at Mercury. In addition, using existing data sets of ICMEs at 1 AU, we investigate key ICME property changes from Mercury to 1 AU. We find good agreement with previous studies for the magnetic field strength dependence on distance, and we also find evidence that ICME deceleration continues past the orbit of Mercury. This paper describes the database of ICMEs from MESSENGER orbital observations around Mercury, which is publicly available through the supporting information (Table S1) associated with this manuscript and the Virtual Energetic Particle Observatory. Our ICME database will prove particularly useful for multipoint spacecraft studies of recent ICMEs, as well as for model validation of ICME properties.
Key Points
Comprehensive database of ICMEs from 3.5 years of MESSENGER Magnetometer observations at Mercury
Three lines of evidence for ICME speed decrease past Mercury's orbit to 1 AU
Magnetic field strength‐distance dependence established from Helios data confirmed with MESSENGER
Although galaxies, groups, and clusters contain ~10% of the baryons, many more reside in the photoionized and shocked-heated intergalactic medium (IGM) and in the circumgalactic medium (CGM). We ...update the baryon census in the (H I) Lyalpha forest and warm-hot IGM (WHIM) at 10 super(5-6) K traced by O VI lambda1032, 1038 absorption. From Enzo cosmological simulations of heating, cooling, and metal transport, we improve the H I and O VI baryon surveys using spatially averaged corrections for metallicity (Z/Z sub(middot in circle)) and ionization fractions (f sub(H I), f sub(O VI)). Statistically, the O VI correction product correlates with column density, (Z/Z sub(middot in circle))f sub(O VI) approximately (0.015)(N sub(O VI)/10 super(14) cm super(-2)) super(0.70), with an N sub(O VI)-weighted mean of 0.01, which doubles previous estimates of WHIM baryon content. We also update the Lyalpha forest contribution to baryon density out to z = 0.4, correcting for the (1 + z) super(3) increase in absorber density, the (1 + z) super(4.4) rise in photoionizing background, and cosmological proper length dl/dz. We find substantial baryon fractions in the photoionized Lyalpha forest (28% + or - 11%) and WHIM traced by O VI and broad-Lyalpha absorbers (25% + or - 8%). The collapsed phase (galaxies, groups, clusters, CGM) contains 18% + or - 4%, leaving an apparent baryon shortfall of 29% + or - 13%. Our simulations suggest that ~15% reside in hotter WHIM (T > or =, slanted 10 super(6) K). Additional baryons could be detected in weaker Lyalpha and O VI absorbers. Further progress requires higher-precision baryon surveys of weak absorbers, down to minimum column densities N sub(H I) > or =, slanted 10 super(12.0) cm super(-2), N sub(O VI) > or =, slanted 10 super(12.5) cm super(-2), N sub(O VII) > or =, slanted 10 super(14.5) cm super(-2), using high signal-to-noise data from high-resolution UV and X-ray spectrographs.
Abstract
We revisit the question of how the unstable scattering of interstellar pickup ions (PUIs) may drive turbulence in the outer solar wind and why the energy released into fluctuations by this ...scattering appears to be significantly less than the standard bispherical prediction. We suggest that energization of the newly picked-up ions by the ambient turbulence during the scattering process can result in a more spherical distribution of PUIs and reduce the generated fluctuation energy to a level consistent with the observations of turbulent intensities and core solar wind heating. This scenario implies the operation of a self-regulation mechanism that maintains the observed conditions of turbulence and heating in the PUI-dominated solar wind.
We use high-quality, medium-resolution Hubble Space Telescope/Cosmic Origins Spectrograph (HST/COS) observations of 82 UV-bright active galactic nuclei (AGNs) at redshifts zAGN < 0.85 to construct ...the largest survey of the low-redshift intergalactic medium (IGM) to date: 5138 individual extragalactic absorption lines in H i and 25 different metal-ion species grouped into 2611 distinct redshift systems at zabs < 0.75 covering total redshift pathlengths ?zH i = 21.7 and zO vi = 14.5. Our semi-automated line-finding and measurement technique renders the catalog as objectively defined as possible. We find substantial clustering of H i absorbers on scales of v = 50-300 km s-1 with no significant clustering at v gsim 1000 km s-1. Splitting the sample into strong and weak absorbers, we see that most of the clustering occurs in strong, NH i gsim 1013.5 cm-2, metal-bearing IGM systems.
Drought, defined as a marked deficiency of precipitation relative to normal, occurs as periods of below-average precipitation or complete failure of precipitation inputs, and can be limited to a ...single season or prolonged over multiple years. Grasslands are typically quite sensitive to drought, but there can be substantial variability in the magnitude of loss of ecosystem function. We hypothesized that differences in how drought occurs may contribute to this variability. In four native Great Plains grasslands (three C
4
- and one C
3
-dominated) spanning a ~ 500-mm precipitation gradient, we imposed drought for four consecutive years by (1) reducing each rainfall event by 66% during the growing season (chronic drought) or (2) completely excluding rainfall during a shorter portion of the growing season (intense drought). The drought treatments were similar in magnitude but differed in the following characteristics: event number, event size and length of dry periods. We observed consistent drought-induced reductions (28–37%) in aboveground net primary production (ANPP) only in the C
4
-dominated grasslands. In general, intense drought reduced ANPP more than chronic drought, with little evidence that drought duration altered this pattern. Conversely, belowground net primary production (BNPP) was reduced by drought in all grasslands (32–64%), with BNPP reductions greater in intense vs. chronic drought treatments in the most mesic grassland. We conclude that grassland productivity responses to drought did not strongly differ between these two types of drought, but when differences existed, intense drought consistently reduced function more than chronic drought.
Aging results in impaired neurogenesis in the two neurogenic niches of the adult mammalian brain, the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle. While ...significant work has characterized intrinsic cellular changes that contribute to this decline, it is increasingly apparent that the systemic environment also represents a critical driver of brain aging. Indeed, emerging studies utilizing the model of heterochronic parabiosis have revealed that immune-related molecular and cellular changes in the aging systemic environment negatively regulate adult neurogenesis. Interestingly, these studies have also demonstrated that age-related decline in neurogenesis can be ameliorated by exposure to the young systemic environment. While this burgeoning field of research is increasingly garnering interest, as yet, the precise mechanisms driving either the pro-aging effects of aged blood or the rejuvenating effects of young blood remain to be thoroughly defined. Here, we review how age-related changes in blood, blood-borne factors, and peripheral immune cells contribute to the age-related decline in adult neurogenesis in the mammalian brain, and posit both direct neural stem cell and indirect neurogenic niche-mediated mechanisms.
Phytoplankton production drives marine ecosystem trophic-structure and global fisheries yields. Phytoplankton biomass is particularly influential near coral reef islands and atolls that span the ...oligotrophic tropical oceans. The paradoxical enhancement in phytoplankton near an island-reef ecosystem--Island Mass Effect (IME)--was first documented 60 years ago, yet much remains unknown about the prevalence and drivers of this ecologically important phenomenon. Here we provide the first basin-scale investigation of IME. We show that IME is a near-ubiquitous feature among a majority (91%) of coral reef ecosystems surveyed, creating near-island 'hotspots' of phytoplankton biomass throughout the upper water column. Variations in IME strength are governed by geomorphic type (atoll vs island), bathymetric slope, reef area and local human impacts (for example, human-derived nutrient input). These ocean oases increase nearshore phytoplankton biomass by up to 86% over oceanic conditions, providing basal energetic resources to higher trophic levels that support subsistence-based human populations.
Objective Retrograde pedal access may allow the treatment of tibial occlusive lesions when standard endovascular techniques fail. We aimed to analyze the outcomes in patients with chronic limb ...ischemia (Rutherford class IV and V) who were not surgical candidates for a tibial bypass and had undergone an unsuccessful attempt at revascularization through an antegrade access. Methods During a 3-year period, a retrograde pedal access was selectively chosen when a popliteal or tibial lesion could not be crossed through an antegrade approach. Retrograde pedal access was performed under ultrasound guidance using a 4F micropuncture coaxial sheath. All interventions were performed in a sheathless fashion using a 0.014- or 0.018-inch “bareback” wire as support for a 2- or 2.5-mm balloon angioplasty catheter to cross and treat tibial chronic total occlusions that could not be treated through an antegrade approach. Routine anticoagulation and dual-antiplatelet therapy were used periprocedurally. Antegrade access was used to treat any lesion that required a stent placement after the retrograde wire was snared and brought through the antegrade guidecatheter. Patient indications and comorbidities were recorded. Outcomes analyzed were limb salvage rate, periprocedural complications, and mortality. Mean and standard deviations were calculated. The Kaplan-Meier method was used to calculate limb salvage rates. Results A review of the 681 lower extremity angiograms in which a patient had an intervention from July 2010 through December 2013 identified 13 patients (nine men) in whom a retrograde pedal access was performed (mean age, 71.4 ± 12.4 years). Among these, diabetes was present in 10 of 13 (77%) and chronic renal insufficiency (stages II-V) in nine (69%). Five (38%) had undergone contralateral amputation. Indications for a retrograde pedal revascularization were Rutherford chronic limb ischemia class IV in two (15%) and class V in 11 (85%). Technical success rate was 69% (nine of 13). A variety of popliteal (two of 13) and tibial (13 of 13) vessels were treated with angioplasty alone (10 of 13) or angioplasty/stent placement (three of 13) through a retrograde approach. The technical failures were due to inability to cross the occlusion(s). Periprocedurally, there was one myocardial infarction but no local complications, worsening renal insufficiency, or deaths. At a mean follow-up of 17.1 ± 10.3 months, the limb salvage rate was 77% (10 of 13). There was a high mortality rate of 23% (three of 13) on follow-up in this cohort, occurring at median 6 ± 4 months. Conclusions Retrograde pedal access for limb salvage in high-risk patients is feasible and safe, with acceptable limb salvage rates at intermediate follow-up. Appropriate candidates are those who have failed an antegrade intervention and are poor candidates for a tibial bypass. Future studies should test whether this mode of revascularization has favorable limb salvage rates in larger patient populations and seek to identify specific patient populations who will benefit from this technique.
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