Body-size comparisons of alpine- and forest-wintering woodland caribou herds in the Yukon

1999 ◽  
Vol 77 (7) ◽  
pp. 1017-1024 ◽  
Author(s):  
Gerald W Kuzyk ◽  
Michael M Dehn ◽  
Richard S Farnell
Keyword(s):  
Rangifer Tarandus ◽  
Body Proportions ◽  
Woodland Caribou ◽  
Physical Measurements ◽  
Alpine Zone ◽  
Selective Forces ◽  
The Difference ◽  
And Migration ◽  
Southwest Part ◽  
Body Condition Scores

Information from radiotelemetry studies has shown that woodland caribou (Rangifer tarandus caribou) living in the snow-shadow region of the southwest part of the Yukon spend part of the winter in the subalpine and alpine zones. Other woodland caribou living in areas with high snowfall in central and eastern Yukon have traditional winter ranges in forested lowlands. We theorize that selective forces exerted by the wintering environments will have induced differences in caribou body characteristics, and we test the hypothesis that woodland caribou that winter in the alpine zone are phenotypically different from those wintering in forested environments. We compared five physical measurements from 382 female woodland caribou in 11 Yukon herds. Our results indicate a significant (14 cm) difference in shoulder height between forest- and alpine-wintering groups, but provide no support for the hypothesis that the difference is due to snow depth. There were no significant differences in other body measurements or in body proportions. It is also unlikely that the difference in shoulder height is due to winter nutrition, since body condition scores did not differ between forest- and alpine-wintering groups. We discuss seasonal nutrition, predation, and migration as alternative explanations for our results.

scholarly journals Using caribou knowledge in expanding the Wabakimi protected area

Rangifer ◽  
1998 ◽  
Vol 18 (5) ◽  
pp. 183 ◽  
Author(s):  
Peter N. Duinker ◽  
Ted R. Armstrong ◽  
Bruce T. Hyer ◽  
Bruce Petersen
Keyword(s):  
Protected Area ◽  
Rangifer Tarandus ◽  
Initial Assessment ◽  
Final Report ◽  
Second Phase ◽  
Woodland Caribou ◽  
The Government ◽  
Level Scale ◽  
And Migration ◽  
Full Consensus

When Wabakimi Wilderness Park was created in 1983, conservation of woodland caribou (Rangifer tarandus caribou) was one of the primary considerations. Twelve years later, in April 1995, the Government of Ontario announced that the Park, measuring some 155 000 ha, was to be expanded into a ca. 890 000 ha protected area. This was done following 2.5 yr of deliberations of the Wabakimi Park Boundary Committee. The Committee tried to reach consensus on an expanded protected area by examining a variety of options in terms of criteria related to a range of key values, one of which was woodland caribou. The analysis procedure involved dividing the 1.25-million-ha study area into more than sixty "assessment units". These were defined primarily on the basis of approximate sub-watershed boundaries. Each assessment unit was ranked on a five-level scale with respect to goodness for each value, including seasonal caribou habitat. High-value habitats for wintering, calving, and migration dominated the assessment of habitat importance for caribou.The initial assessment phase included six park expansion concepts ranging in size from just over 200 000 ha to about 1 million ha. One of the concepts (about 750 000 ha), was based specifically on the caribou value. In the second phase, four refined options were examined, ranging from just under 600 000 to roughly a million ha. Two additional options were added to the four and submitted to the Ontario Ministry of Natural Resources for consideration. The Committee was, in the end, unable to reach full consensus on which of the final options to recommend. However, upon consideration of the Committee's final report and other input, the Ontario Government announced in April 1995 the more than five-fold expansion. The new protected area contains about 475 000 ha of high-value caribou habitat. Caribou were a key value in determining both the ultimate size and configuration of the expansion.

scholarly journals Intranasal delivery of mitochondria for treatment of Parkinson’s Disease model rats lesioned with 6-hydroxydopamine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jui-Chih Chang ◽  
Yi-Chun Chao ◽  
Huei-Shin Chang ◽  
Yu-Ling Wu ◽  
Hui-Ju Chang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Olfactory Bulb ◽  
Disease Model ◽  
Intranasal Delivery ◽  
The Difference ◽  
And Migration ◽  
6 Hydroxydopamine ◽  
Locomotor Behaviors ◽  
Migratory Stream

AbstractThe feasibility of delivering mitochondria intranasally so as to bypass the blood–brain barrier in treating Parkinson's disease (PD), was evaluated in unilaterally 6-OHDA-lesioned rats. Intranasal infusion of allogeneic mitochondria conjugated with Pep-1 (P-Mito) or unconjugated (Mito) was performed once a week on the ipsilateral sides of lesioned brains for three months. A significant improvement of rotational and locomotor behaviors in PD rats was observed in both mitochondrial groups, compared to sham or Pep-1-only groups. Dopaminergic (DA) neuron survival and recovery > 60% occurred in lesions of the substantia nigra (SN) and striatum in Mito and P-Mito rats. The treatment effect was stronger in the P-Mito group than the Mito group, but the difference was insignificant. This recovery was associated with restoration of mitochondrial function and attenuation of oxidative damage in lesioned SN. Notably, P-Mito suppressed plasma levels of inflammatory cytokines. Mitochondria penetrated the accessory olfactory bulb and doublecortin-positive neurons of the rostral migratory stream (RMS) on the ipsilateral sides of lesions and were expressed in striatal, but not SN DA neurons, of both cerebral hemispheres, evidently via commissural fibers. This study shows promise for intranasal delivery of mitochondria, confirming mitochondrial internalization and migration via RMS neurons in the olfactory bulb for PD therapy.

scholarly journals Conserving woodland caribou habitat while maintaining timber yield: a graph theory approach

2016 ◽  
Vol 46 (7) ◽  
pp. 914-923 ◽  
Author(s):  
Jonathan L.W. Ruppert ◽  
Marie-Josée Fortin ◽  
Eldon A. Gunn ◽  
David L. Martell
Keyword(s):  
Graph Theory ◽  
Rangifer Tarandus ◽  
High Volume ◽  
Timber Harvesting ◽  
Optimization Approach ◽  
Theory Approach ◽  
Heuristic Procedure ◽  
Woodland Caribou ◽  
Old Growth ◽  
Old Growth Forest

The fragmentation and loss of old-growth forest has led to the decline of many forest-dwelling species that depend on old-growth forest as habitat. Emblematic of this issue in many areas of the managed boreal forest in Canada is the threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). We develop a methodology to help determine when and how timber can be harvested to best satisfy both industrial timber supply and woodland caribou habitat requirements. To start, we use least-cost paths based on graph theory to determine the configuration of woodland caribou preferred habitat patches. We then developed a heuristic procedure to schedule timber harvesting based on a trade-off between merchantable wood volume and the remaining amount of habitat and its connectivity during a planning cycle. Our heuristic can attain 84% of the potential woodland caribou habitat that would be available in the absence of harvesting at the end of a 100 year planning horizon. Interestingly, this is more than that which is attained by the current plan (50%) and a harvesting plan that targets high volume stands (32%). Our results indicate that our heuristic procedure (i.e., an ecologically tuned optimization approach) may better direct industrial activities to improve old-growth habitat while maintaining specified timber production levels.

The Synthesis and Migration of Nuclear Proteins during Mitosis and differentiation of Cells in Rats

1965 ◽  
Vol s3-106 (75) ◽  
pp. 229-240
Author(s):  
R. T. SIMS
Keyword(s):  
Granular Cell ◽  
Nuclear Proteins ◽  
Photographic Emulsion ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Cell Layers ◽  
The Difference ◽  
Mitotic Figures ◽  
And Migration ◽  
Silver Grains

Hooded rats were given an intraperitoneal injection of 3H-tyrosine, and killed in pairs 10 min, 30 min, 12 h, 36 h, 7 days, and 30 days later. A piece of skin with white growing hair, and the tongue, were taken from each animal and radioautographs were prepared. Silver grains were counted over whole nuclei and whole mitotic figures of the germinal cells and whole nuclei of differentiating cells of both tissues. It was found that the interphase nuclei have significantly more silver grains over them than the chromosomes at all stages of mitosis and there are virtually no grains over metaphase, anaphase, and early telophase chromosomes in both tissues of all the animals killed up to 36 h after the injection. The difference between the grain counts over the interphase nuclei and the chromosomes of dividing cells is at least 20-fold at 30 min in the hair matrix, at least 5-fold at 30 min in the tongue and at 36 h in both tissues. It was established that the differences observed between the radioactivities of the nuclei and chromosomes of mitotic figures are real from estimates of: the radioactivity of the cell cytoplasm, volumes of the metaphase chromosomes and interphase nuclei within 1µ of the photographic emulsion, and the volumes of cytoplasm separating the photographic emulsion and these structures. No protein synthesis was demonstrable in the chromosomes during metaphase, anaphase, and early telophase. Nuclear proteins leave the chromosomes during prophase and prometaphase and return to the nucleus during late telophase. The cells in the matrix and upper bulb of the growing hair follicle and those in the germinal, prickle, and granular cell layers of the tongue are in different functional states; 30 min after injection of 3H-tyrosine they have different amounts of it in their nuclear proteins. It is suggested that the amount incorporated into each nucleus is related to the rate at which proteins are being synthesized by the cell.

If You Build It, Will They Come? Caribou Habitat Restoration for Pipeline Projects

2014 ◽  
Author(s):  
Brian Coupal ◽  
Paula Bentham
Keyword(s):  
Habitat Management ◽  
Habitat Restoration ◽  
Rangifer Tarandus ◽  
Local Population ◽  
Landscape Fragmentation ◽  
Lessons Learned ◽  
Woodland Caribou ◽  
Recovery Strategy ◽  
Control Programs ◽  
Northeastern Alberta

The federal Recovery Strategy for the Woodland Caribou (Rangifer tarandus caribou), Boreal Population in Canada, identifies coordinated actions to reclaim woodland caribou habitat as a key step to meeting current and future caribou population objectives. Actions include restoring industrial landscape features such as roads, seismic lines, pipelines, cut-lines, and cleared areas in an effort to reduce landscape fragmentation and the changes in caribou population dynamics associated with changing predator-prey dynamics in highly fragmented landscapes. Reliance on habitat restoration as a recovery action within the federal Recovery Strategy is high, identifying 65% undisturbed habitat in a caribou range as the threshold to providing a 60% chance that a local population will be self-sustaining. In alignment with the federal Recovery Strategy, Alberta’s Provincial Woodland Caribou Policy identifies habitat restoration as a critical component of long-term caribou habitat management. Habitat restoration initiatives of Alberta’s historical industrial footprint within caribou ranges began in 2001 and have largely focused on linear corridors, including pipelines. Initiatives include revegetation treatments, access control programs and studies, and restricting the growth of plant species that are favourable to moose and deer, the primary prey for wolves. Habitat restoration for pipelines also includes pre-construction planning to reduce disturbance and create line-of-sight breaks, and construction techniques that promote natural vegetation recovery. Lessons learned from habitat restoration programs implemented on pipeline projects in northeastern Alberta will be shared as an opportunity to improve common understanding of restoration techniques, the barriers to implementation, and potential outcomes.

scholarly journals Putting the environmental impact assessment process into practice for woodland caribou in the Alberta Oil Sands Region

Rangifer ◽  
2005 ◽  
Vol 25 (4) ◽  
pp. 89
Author(s):  
Paula R. Bentham
Keyword(s):  
Oil Sands ◽  
Rangifer Tarandus ◽  
Assessment Process ◽  
Mitigation Measures ◽  
Primary Role ◽  
Woodland Caribou ◽  
The Government ◽  
Current Operating ◽  
Impact Predictions

Since 1985, woodland caribou (Rangifer tarandus caribou) have been designated as a threatened species in Alberta. Populations studied since the 1970s have been stable or declining, with no population increases documented. Resource expansion into previously undeveloped areas and associated increases in access have been implicated as possible causes for the declines. To facilitate development on caribou ranges, while ensuring the integrity and supply of caribou habitat, standing committees have been formed. The primary role of the committees is to act as advisory bodies to the government and to search for effective and efficient industrial operating guidelines. Recent research has been conducted on the responses of woodland caribou ecotypes to increased human and predator access. Based on this research, operating guidelines have been refined and implemented through Caribou Protection Plans. I discuss how the current operating guidelines are put into practice and linked to the Environmental Assessment process within the Oil Sands Region of Alberta. In particular, I discuss the origination of impact predictions, specific mitigation measures to reduce impacts and monitoring.

Fascioloides magna (Trematoda) in woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador

1988 ◽  
Vol 66 (2) ◽  
pp. 475-479 ◽  
Author(s):  
Murray W. Lankester ◽  
Stu Luttich
Keyword(s):  
Rangifer Tarandus ◽  
Age Groups ◽  
Liver Weight ◽  
Rangifer Tarandus Caribou ◽  
Woodland Caribou ◽  
Intensity Of Infection ◽  
Fascioloides Magna ◽  
The Mean ◽  
George River ◽  
Liver Flukes

Fifty-eight percent of woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador, were infected with up to 110 giant American liver flukes (Fascioloides magna). The prevalence and intensity of infection did not differ between 2 sampling years or between sexes. Prevalence tended to increase with age while intensity did not differ among age groups. Liver weight increased with intensity of infection but condition, as measured by the mean depth of back fat, did not differ between infected and uninfected animals. Caribou must be considered a suitable host of F. magna since the growth and maturation of the parasite and lesions produced in Rangifer resemble those in deer and wapiti.

scholarly journals Mechanics of cortical folding: stress, growth and stability

2018 ◽  
Vol 373 (1759) ◽  
pp. 20170321 ◽  
Author(s):  
K. E. Garcia ◽  
C. D. Kroenke ◽  
P. V. Bayly
Keyword(s):  
Cortical Development ◽  
Experimental Studies ◽  
Temporal Patterns ◽  
Cortical Plate ◽  
Cortical Folding ◽  
Mechanical Instability ◽  
Outer Cortex ◽  
Physical Measurements ◽  
Spatio Temporal ◽  
And Migration

Cortical folding, or gyrification, coincides with several important developmental processes. The folded shape of the human brain allows the cerebral cortex, the thin outer layer of neurons and their associated projections, to attain a large surface area relative to brain volume. Abnormal cortical folding has been associated with severe neurological, cognitive and behavioural disorders, such as epilepsy, autism and schizophrenia. However, despite decades of study, the mechanical forces that lead to cortical folding remain incompletely understood. Leading hypotheses have focused on the roles of (i) tangential growth of the outer cortex, (ii) spatio-temporal patterns in the birth and migration of neurons, and (iii) internal tension in axons. Recent experimental studies have illuminated not only the fundamental cellular and molecular processes underlying cortical development, but also the stress state, mechanical properties and spatio-temporal patterns of growth in the developing brain. The combination of mathematical modelling and physical measurements has allowed researchers to evaluate hypothesized mechanisms of folding, to determine whether each is consistent with physical laws. This review summarizes what physical scientists have learned from models and recent experimental observations, in the context of recent neurobiological discoveries regarding cortical development. Here, we highlight evidence of a combined mechanism, in which spatio-temporal patterns bias the locations of primary folds (i), but tangential growth of the cortical plate induces mechanical instability (ii) to propagate primary and higher-order folds. This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.

Sign in / Sign up

Export Citation Format

Share Document