scholarly journals Documenting at‐risk status of terrestrial ecosystems in temperate and tropical North America

2022 ◽  
Author(s):  
Patrick J. Comer ◽  
John C. Hak ◽  
Emily Seddon
Keyword(s):  
At Risk ◽  
North America ◽  
Terrestrial Ecosystems ◽  
Risk Status

Prevalence, awareness, characteristics, and health outcomes associated with COPD at-risk status among adults in Japan

2015 ◽  
Vol 16 (4) ◽  
pp. 501-512 ◽  
Author(s):  
Hisamitsu Omori ◽  
Daisuke Yoshimoto ◽  
Maya Kumar ◽  
Amir Goren
Keyword(s):  
At Risk ◽  
Health Outcomes ◽  
Risk Status

Modernisation of the Hymenoptera: ants, bees, wasps, and sawflies of the early Eocene Okanagan Highlands of western North America

2018 ◽  
Vol 150 (2) ◽  
pp. 205-257 ◽  
Author(s):  
S. B. Archibald ◽  
Alexandr P. Rasnitsyn ◽  
Denis J. Brothers ◽  
Rolf W. Mathewes
Keyword(s):  
North America ◽  
Terrestrial Ecosystems ◽  
Sensu Stricto ◽  
Late Eocene ◽  
Trophic Guilds ◽  
Early Eocene ◽  
Western North America ◽  
Family Level ◽  
Okanagan Highlands ◽  
Taphonomic Processes

AbstractMost major modern families of Hymenoptera were established in the Mesozoic, but the diversifications within ecologically key trophic guilds and lineages that significantly influence the character of modern terrestrial ecosystems – bees (Apiformes), ants (Formicidae), social Vespidae, parasitoids (Ichneumonidae), and phytophagous Tenthredinoidea – were previously known to occur mostly in the middle to late Eocene. We find these changes earlier, seen here in the early Eocene Okanagan Highlands fossil deposits of western North America. Some of these may have occurred even earlier, but have been obscured by taphonomic processes. We provide an overview of the Okanagan Highlands Hymenoptera to family level and in some cases below that, with a minimum of 25 named families and at least 30 when those tentatively assigned or distinct at family level, but not named are included. Some are poorly known as fossils (Trigonalidae, Siricidae, Peradeniidae, Monomachidae), and some represent the oldest confirmed occurrences (Trigonalidae, Pompilidae, Sphecidaesensu stricto, Peradeniidae, Monomachidae, and possibly Halictidae). Some taxa previously thought to be relictual or extinct by the end of the Cretaceous (Angarosphecidae, Archaeoscoliinae, some Diapriidae) are present and sometimes abundant in the early Eocene. Living relatives of some taxa are now present in different climate regimes or on different continents.

Coping styles and support sources of at-risk students

2000 ◽  
Vol 17 (2) ◽  
pp. 58-69 ◽  
Author(s):  
Sue Fischmann ◽  
John L. Cotterell
Keyword(s):  
At Risk ◽  
Family Support ◽  
School Environment ◽  
Professional Training ◽  
Comparison Group ◽  
Coping Styles ◽  
At Risk Students ◽  
Support Programs ◽  
Risk Status ◽  
School Counsellors

AbstractThis study compared perceptions of the school environment, coping and enacted support between Year 10 students identified as educationally at risk (n = 31) and a comparison group of students in the same year level (n = 97), at two periods in the school term. At-risk students perceived the school environment to show significantly less concern for students and used problem-focused coping less frequently than did comparison students. Regardless of risk status, girls used social support more frequently than boys did. At-risk girls accessed peer support more than family support ond also frequently contacted school counsellors to discuss problems. At-risk boys rarely sought support from anyone. Implications for school support programs are twofold. Teachers may need additional professional training in how to employ socially supportive practices. In addition, school counsellors may need to foster informal opportunities for social participation, in order to connect vulnerable boys to peers and adults.

scholarly journals Cretaceous vegetational change: a biomal perspective

1992 ◽  
Vol 6 ◽  
pp. 295-295
Author(s):  
Garland R. Upchurch
Keyword(s):  
Species Diversity ◽  
North America ◽  
Late Cretaceous ◽  
High Latitude ◽  
Deciduous Forest ◽  
Terrestrial Ecosystems ◽  
High Latitudes ◽  
Coastal Regions ◽  
Show Evidence ◽  
Angiosperm Pollen

The Cretaceous rise of flowering plants marked an important transition in the modernization of terrestrial ecosystems. Well documented is the diversification of angiosperm pollen during the mid-Cretaceous and the migration of angiosperms from low latitudes to middle and high latitudes during the Barremian to Cenomanian. Global compilations of “species” diversity indicate a rapid rise in angiosperm diversity during the Albian to Cenomanian. This rise parallels a decline in the species diversity of archaic pteridophytes and the gymnosperm orders Cycadales, Bennettitales, Ginkgoales, Czekanowskiales, and Caytoniales. Late Cretaceous floras show more gradual trends in species diversity than mid-Cretaceous floras.Megafloral reconstructions of vegetation and climate for North America and other continents indicate warm temperatures in coastal regions of middle to high latitudes. Cretaceous biomes, however, often cannot be compared closely with Recent biomes. During much of the Cretaceous, conifers and other gymnosperms shared dominance with angiosperms in tropical and subtropical vegetation, unlike the Recent. During the Late Cretaceous, tropical rainforest was areally restricted. The few known leaf megafloras from equatorial regions indicate subhumid, rather than rainforest, conditions. Desert and semi-desert were widespread at lower latitudes and are documented by the occurrence of evaporite minerals in China, Africa, Spain, Mexico, and South America. Mid-latitude vegetation consisted of open-canopy broadleaved and coniferous evergreen woodlands that existed under subhumid conditions and low seasonality. High-latitude vegetation of the Northern Hemisphere consisted of coniferous and broadleaved deciduous forest, rather than boreal forest and tundra. High-latitude vegetation from coastal regions of the Southern Hemisphere consisted of evergreen conifers and angiosperms. Rainforest conditions appear to have been largely restricted to polar latitudes.Data on relative abundance, though often incomplete, indicate that angiosperms became ecologically important in tropical to warm subtropical broadleaved evergreen forests and woodlands by the Cenomanian. However, their rise to dominance took longer in other biomes. Conifers formed an important component of many Late Cretaceous biomes, and the persistence of archaic gymnosperms was strongly influenced by climate. Deciduous Ginkgoales, Czekanowskiales, Bennettitales, and Caytoniales are rare to absent in Late Cretaceous megafloras from warm subtropical to tropical climates, but they persist in megafloras from cooler climates. Archaic conifers such as Frenelopsis occur in megafloras representing low-latitude desert and semi-desert, but they are generally absent in more humid assemblages. Within mid-latitude broadleaved and coniferous evergreen woodland from North America, conifers show evidence for co-dominance with angiosperms into the early Maastrichtian. However, this co-dominance appears to have ended by latest Maastrichtian, which implies that vegetational reorganization occurred during the last few million years of the Cretaceous in North America.

scholarly journals Recent global CO<sub>2</sub> flux inferred from atmospheric CO<sub>2</sub> observations and its regional analyses

2011 ◽  
Vol 8 (11) ◽  
pp. 3263-3281 ◽  
Author(s):  
F. Deng ◽  
J. M. Chen
Keyword(s):  
North America ◽  
Interannual Variability ◽  
Co2 Flux ◽  
Terrestrial Ecosystems ◽  
Co2 Concentration ◽  
Climate Variations ◽  
Concentration Data ◽  
Surface Exchange ◽  
The North ◽  
Annual Means

Abstract. The net surface exchange of CO2 for the years 2002–2007 is inferred from 12 181 atmospheric CO2 concentration data with a time-dependent Bayesian synthesis inversion scheme. Monthly CO2 fluxes are optimized for 30 regions of the North America and 20 regions for the rest of the globe. Although there have been many previous multiyear inversion studies, the reliability of atmospheric inversion techniques has not yet been systematically evaluated for quantifying regional interannual variability in the carbon cycle. In this study, the global interannual variability of the CO2 flux is found to be dominated by terrestrial ecosystems, particularly by tropical land, and the variations of regional terrestrial carbon fluxes are closely related to climate variations. These interannual variations are mostly caused by abnormal meteorological conditions in a few months in the year or part of a growing season and cannot be well represented using annual means, suggesting that we should pay attention to finer temporal climate variations in ecosystem modeling. We find that, excluding fossil fuel and biomass burning emissions, terrestrial ecosystems and oceans absorb an average of 3.63 ± 0.49 and 1.94 ± 0.41 Pg C yr−1, respectively. The terrestrial uptake is mainly in northern land while the tropical and southern lands contribute 0.62 ± 0.47, and 0.67 ± 0.34 Pg C yr−1 to the sink, respectively. In North America, terrestrial ecosystems absorb 0.89 ± 0.18 Pg C yr−1 on average with a strong flux density found in the south-east of the continent.

scholarly journals Personalized Assessment and Management of Women at Risk for Breast Cancer in North America

2015 ◽  
Vol 11 (2) ◽  
pp. 213-224 ◽  
Author(s):  
Sandhya Pruthi ◽  
Ruth Heisey ◽  
Therese Bevers
Keyword(s):  
Breast Cancer ◽  
At Risk ◽  
North America

scholarly journals Elk (Cervus elaphus) railway mortality in Ontario

2018 ◽  
Vol 96 (9) ◽  
pp. 1066-1070 ◽  
Author(s):  
J.N. Popp ◽  
J. Hamr ◽  
C. Chan ◽  
F.F. Mallory
Keyword(s):  
At Risk ◽  
North America ◽  
Cervus Elaphus ◽  
Snow Depth ◽  
Eastern North America ◽  
Baseline Information ◽  
Collision Mitigation

Wildlife railway research is highly underrepresented in science despite documented wildlife–train collision mortalities. Gathering baseline information is imperative to the development of effective train collision mitigation, especially for at-risk or small reintroduced populations such as elk (Cervus elaphus Linnaeus, 1758) in eastern North America. We tested our hypotheses that elk–train collision rates vary in relation to railway structure and weather by using a combination of radiotelemetry and railway mortality surveys. Elk were closer to the railway in winter than in any other season. Elk–train collision sites were significantly closer to the apex of bends in the railway than random locations along the railway, and collision rates were positively related to snow depth. Railways may be perceived by elk as easy travel corridors, and deep snow likely prohibits escape from oncoming trains. This study gathered important information about an under-studied aspect of wildlife–human conflicts and provides a basis for the investigation of other species that may be affected by railways.

The PRIME North America randomized double-blind clinical trial of olanzapine versus placebo in patients at risk of being prodromally symptomatic for psychosis

2003 ◽  
Vol 61 (1) ◽  
pp. 7-18 ◽  
Author(s):  
T.H McGlashan ◽  
R.B Zipursky ◽  
D Perkins ◽  
J Addington ◽  
T.J Miller ◽  
...  
Keyword(s):  
Clinical Trial ◽  
At Risk ◽  
North America ◽  
Double Blind ◽  
Double Blind Clinical Trial ◽  
Patients At Risk
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