Fates of disappearing individuals in fluctuating populations of Microtus townsendii

1976 ◽  
Vol 54 (9) ◽  
pp. 1507-1518 ◽  
Author(s):  
Ray Hilborn ◽  
Charles J. Krebs
Keyword(s):  
Natural Populations ◽  
Physical Factors ◽  
Summer Drought ◽  
Factors Associated ◽  
University Of British Columbia ◽  
Live Trapping ◽  
Fluctuating Populations ◽  
The University ◽  
Second Period ◽  
Microtus Townsendii

Fates of disappearing individuals were determined for two natural populations of Microtus townsendii by livetrapping of evacuated areas and marginal habitat, and by marking individuals with radioactive tags to locate carcasses. Two hundred and nineteen out of the 454 individuals that disappeared were radioactively tagged during this 3-year study conducted in the University of British Columbia Research Forest near Haney, B.C. Only 30 radioactive tags were recovered on the live-trapping areas. Most disappearances in this vole population must have been caused by dispersal or predation.Most disappearance from increase and peak populations was due to dispersal. Two summer periods of declining numbers were observed; during one such period many individuals' remains were found on the study areas, but during the other period of declining numbers few remains were found. There was no increase in dispersal rate as measured by the above techniques during either decline period. It is concluded that during the first brief period of declining numbers individuals were dying in their nests from physical factors associated with a severe summer drought and during the second period of declining numbers individuals were either moving long distances without going into traps or being taken by predators.

scholarly journals Some aspects of reproduction in the vole Microtus townsendii

1979 ◽  
Vol 57 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Judith L. Anderson ◽  
Rudy Boonstra
Keyword(s):  
British Columbia ◽  
Litter Size ◽  
Forest Litter ◽  
Detailed Account ◽  
Population Fluctuations ◽  
Reproductive Parameters ◽  
University Of British Columbia ◽  
Significant Difference ◽  
The University ◽  
Microtus Townsendii

Changes in various reproductive parameters have pronounced effects on microtine population fluctuations. This study presents a detailed account of reproduction in Microtus townsendii. Populations in two areas were studied. On Westham Island, litter size, estimated by autopsy, was correlated positively with weight. There was no significant difference in litter size between primiparous and multiparous females. Females pregnant in spring had more embryos than those pregnant in summer or fall. Breeding was concentrated in spring and summer, with most females continuously pregnant.In the University of British Columbia Research Forest, litter size at recruitment was found to be unrelated to parity, size, or LAP genotype of the mother. While the size of consecutive litters (determined by autopsy) was significantly repeatable within an individual mother, recruitment litter size was not. Autopsy litter size, as at Westham Island, was largest in spring, but recruitment litter size was largest in autumn. Entire litters were lost most often during winter and summer. Overnight trapping may be responsible for loss of some litters at or just before parturition. Litters born in traps were usually unsuccessful, but otherwise mothers of totally unsuccessful litters seemed to avoid traps. Neither parity nor LAP genotype was related to the loss of entire litters.

scholarly journals Evaluation and Lessons Learned from a Campus as a Living Lab Program to Promote Sustainable Practices

2021 ◽  
Vol 13 (4) ◽  
pp. 1739
Author(s):  
Paul Save ◽  
Belgin Terim Cavka ◽  
Thomas Froese
Keyword(s):  
Learning Curve ◽  
Business Process ◽  
Lessons Learned ◽  
Process Models ◽  
Sustainable Practices ◽  
Business Process Models ◽  
District Energy ◽  
University Of British Columbia ◽  
Living Lab ◽  
The University

Any group that creates challenging goals also requires a strategy to achieve them and a process to review and improve this strategy over time. The University of British Columbia (UBC) set ambitious campus sustainability goals, including a reduction in its greenhouse gas emissions to 33% below the 2007 level by 2015, and 100% by 2050 (UBC, 2006). The University pursued these goals through a number of specific projects (such as major district energy upgrade and a bioenergy facility) and, more generally, through a “Campus as a Living Lab” (CLL) initiative to marry industry, campus operations, and research to drive innovative solutions. The CLL program has achieved significant successes while also demonstrating many opportunities for improvements and lessons learned. The aim of this study was to examine the UBC CLL program, to identify and formalize its operations, to extract key transferable characteristics, and to propose replicable processes that other universities and municipalities can follow to expand their sustainable practices in similar ways. There was a learning curve with implementing a CLL program at UBC; thus, the goal of this study was to potentially shorten this learning curve for others. The research involved an ethnographic approach in which researchers participated in the CLL process, conducted qualitative analysis, and captured the processes through a series of business process models. The research findings are shared in two parts: 1. generalized lessons learned through key transferrable characteristics; 2. a series of generic organizational charts and business process models (BPMs) culminated with learned strategies through defined processes that illustrate what was required to create a CLL program at UBC. A generalized future improvement plan for UBC CLL programs is defined, generic BPMs about CLL projects are evaluated, and the level of engagement of multiple stakeholders through phases of project life cycle given in the conclusion for future use of other Living Lab organizations.

scholarly journals POS0486 FACTORS ASSOCIATED WITH CHRONOTROPIC RESPONSE IN PEOPLE WITH RHEUMATOID ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 475.2-476
Author(s):  
A. Osailan
Keyword(s):  
Rheumatoid Arthritis ◽  
Risk Factors ◽  
Cardiorespiratory Fitness ◽  
Inflammatory Markers ◽  
Exercise Intolerance ◽  
Cvd Risk Factors ◽  
Cvd Risk ◽  
Chronotropic Response ◽  
Factors Associated ◽  
The University

Background:People with rheumatoid arthritis (RA) are at high risk for cardiovascular diseases (CVD) and CVD mortality. Reduced Chronotropic response (CR), which produces exercise intolerance, is known as a contributing factor to CVD and mortality. Studies have shown that people with RA have reduced CR. However, knowledge about the factors associated with CR in people with RA is limited.Objectives:To explore the factors associated with CR including CVD risk factors, inflammatory markers and cardiorespiratory fitness (VO2 peak).Methods:106 people with RA completed a treadmill exercise tolerance test while heart rate (HR) was monitored via 12 leads ECG. CR was defined as the percentage of [(achieved peak HR minus resting HR) divided by (age-predicted maximum HR minus resting HR)]. Serological CVD risk factors and inflammatory markers including lipids profile, markers of insulin resistance and sensitivity (HOMA, QUICKi), high sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), fibrinogen and white blood cells (WBC) were examined via a fasted blood sample. VO2 peak was assessed via breath-by-breath gas analysis.Results:34% had reduced CR based on the cut-off value (≤ 80%) and the average CR was 86.2 ± 21%. Body mass index (r=-0.33, p=.001), HOMA (r=-0.26, p=.009), hsCRP (r=-0.23, p=.02), ESR (r=-0.21, p=.04), fibrinogen (r=-0.2, p=.05), WBC (r=-0.21, p=.04) were inversely associated with CR, whereas, high density lipoprotein (HDL) (r=0.43, p<.001), QUICKi (r=0.31, p=.002), and VO2 peak (r=0.4, p<.001) were positively associated with CR. When all the variables were entered into a stepwise linear regression, HDL (p<.001) and VO2 peak (p=.009) were independently associated with CR.Conclusion:The current findings suggest that CR in RA was associated with many CVD risk factors, inflammatory markers, and cardiorespiratory fitness. Among all the varibales, HDL and cardiorespiratory fitness were moderately and independently associated with CR. Future studies should investigate the effect of improving these associated variables on CR in people with RA via exercise training programes.Acknowledgements:Thanks to physical activity in Rheumatoid arthritis research team and Research department in Dudley Hospital. Sincere appreciation and gratitude to Dr Jet Veldhuizen van Zanten, Prof. Joan Duda, and Prof. George Kitas from the University of Birmingham and Prof. George Metsios from the University of Wolverhampton.Disclosure of Interests:None declared

Critical thinking or common sense?

2016 ◽  
Vol 179 (7) ◽  
pp. i-ii
Author(s):  
Vicki Adams
Keyword(s):  
British Columbia ◽  
Critical Thinking ◽  
Common Sense ◽  
Animal Science ◽  
University Of British Columbia ◽  
The University

Vicki Adams grew up in Vancouver, Canada, and graduated with a degree in animal science from the University of British Columbia before being accepted into vet school in Saskatchewan. Her animal science background has given her the population perspective that is so important in epidemiology and she now runs her own consulting company, Vet Epi

scholarly journals Peripartum and neonatal factors associated with the persistence of neonatal brachial plexus palsy at 1 year: a review of 382 cases

2016 ◽  
Vol 17 (5) ◽  
pp. 618-624 ◽  
Author(s):  
Thomas J. Wilson ◽  
Kate W. C. Chang ◽  
Suneet P. Chauhan ◽  
Lynda J. S. Yang
Keyword(s):  
Brachial Plexus ◽  
Prediction Algorithm ◽  
University Of Michigan ◽  
Brachial Plexus Palsy ◽  
Factors Associated ◽  
Neonatal Brachial Plexus Palsy ◽  
Active Range Of Motion ◽  
Wide Range ◽  
Nerve Surgery ◽  
The University

OBJECTIVE Neonatal brachial plexus palsy (NBPP) occurs due to the stretching of the nerves of the brachial plexus before, during, or after delivery. NBPP can resolve spontaneously or become persistent. To determine if nerve surgery is indicated, predicting recovery is necessary but difficult. Historical attempts explored the association of recovery with only clinical and electrodiagnostic examinations. However, no data exist regarding the neonatal and peripartum factors associated with NBPP persistence. METHODS This retrospective cohort study involved all NBPP patients at the University of Michigan between 2005 and 2015. Peripartum and neonatal factors were assessed for their association with persistent NBPP at 1 year, as defined as the presence of musculoskeletal contractures or an active range of motion that deviated from normal by > 10° (shoulder, elbow, hand, and finger ranges of motion were recorded). Standard statistical methods were used. RESULTS Of 382 children with NBPP, 85% had persistent NBPP at 1 year. A wide range of neonatal and peripartum factors was explored. We found that cephalic presentation, induction or augmentation of labor, birth weight > 9 lbs, and the presence of Horner syndrome all significantly increased the odds of persistence at 1 year, while cesarean delivery and Narakas Grade I to II injury significantly reduced the odds of persistence. CONCLUSIONS Peripartum/neonatal factors were identified that significantly altered the odds of having persistent NBPP at 1 year. Combining these peripartum/neonatal factors with previously published clinical examination findings associated with persistence should allow the development of a prediction algorithm. The implementation of this algorithm may allow the earlier recognition of those cases likely to persist and thus enable earlier intervention, which may improve surgical outcomes.

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