Publications by authors named "P C Catling"

7 Publications

Using herbarium-derived DNAs to assemble a large-scale DNA barcode library for the vascular plants of Canada.

Appl Plant Sci 2017 Dec 22;5(12). Epub 2017 Dec 22.

Centre for Biodiversity Genomics, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.

Premise Of The Study: Constructing complete, accurate plant DNA barcode reference libraries can be logistically challenging for large-scale floras. Here we demonstrate the promise and challenges of using herbarium collections for building a DNA barcode reference library for the vascular plant flora of Canada.

Methods: Our study examined 20,816 specimens representing 5076 of 5190 vascular plant species in Canada (98%). For 98% of the specimens, at least one of the DNA barcode regions was recovered from the plastid loci and and from the nuclear ITS2 region. We used beta regression to quantify the effects of age, type of preservation, and taxonomic affiliation (family) on DNA sequence recovery.

Results: Specimen age and method of preservation had significant effects on sequence recovery for all markers, but influenced some families more (e.g., Boraginaceae) than others (e.g., Asteraceae).

Discussion: Our DNA barcode library represents an unparalleled resource for metagenomic and ecological genetic research working on temperate and arctic biomes. An observed decline in sequence recovery with specimen age may be associated with poor primer matches, intragenomic variation (for ITS2), or inhibitory secondary compounds in some taxa.
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http://dx.doi.org/10.3732/apps.1700079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749818PMC
December 2017

An attributable cost model for a telecare system using advanced community alarms.

J Telemed Telecare 2001 ;7(2):63-72

School of Science and Engineering, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, UK.

We have developed an attributable cost model for a city-based telecare scheme involving 11,618 community alarm users. The equipment was assumed to cost 500 Pounds-1000 Pounds per installation, compared with 175 Pounds for the current system. Because of the significant additional capital cost of the proposed system, it would be necessary to borrow to finance it. For example, if the home equipment cost 500 Pounds per unit, an additional 2.2 million Pounds would be required. Nonetheless, it would be possible to achieve a return on the investment after 10 years. The principal savings would arise from reduced hospital bed costs and reduced residential care. The model suggests that the financial benefits of the proposed system would occur in the ratio of 4% to the local authority housing department, 43% to the National Health Service and 53% to the residential care provider.
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http://dx.doi.org/10.1258/1357633011936174DOI Listing
May 2001

Limits to predator regulation of rabbits in Australia: evidence from predator-removal experiments.

Oecologia 1992 Jan;89(1):102-112

Division of Wildlife and Ecology, CSIRO, PO Box 84, 2602, Lyneham, ACT, Australia.

Predator-prey studies in semi-arid eastern Australia demonstrated that populations of rabbits (Oryctolagus cuniculus) could be regulated by predators. The functional, numerical and total responses of foxes (Vulpes vulpes) to rabbits and the numerical response of feral cats (Felis catus) to rabbits, are described. Measurement of the rabbit component of foxes' stomach contents indicates a Type III functional response. The size of the fox population in summer was dependent on the availability of rabbits over the immediately preceding rabbit breeding season but there appeared to be no density-dependent aggregation of young foxes in areas of surplus food. The total response of foxes, estimated using the short-term numerical response of dispersing foxes, was directly density-dependent for low rabbit densities and inversely density-dependent for high rabbit densities. Two states are possible with this form of total response: a state with low rabbit densities regulated by predators and a state with high rabbit densities which occurs when rabbits escape predator regulation. The boundary between regulation and non-regulation by predators was demonstrated by a predator-removal experiment. In the treated areas, predators were initially culled and rabbits increased to higher densities than in an untreated area where predators were always present. When predators were allowed back into the treated areas, rabbit populations continued to increase and did not decline to the density in the untreated area. This is the critical evidence for a two-state system. When predators were present, rabbits could be maintained at low densities which were in the density-dependent part of the total response curve for foxes. Exceptionally high rabbit recruitment, or artificially reduced predation, could result in rabbits escaping predator-regulation. Under these circumstances, rabbits could move into the inversely density-dependent region of the total response curve for foxes.
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http://dx.doi.org/10.1007/BF00319021DOI Listing
January 1992

Prolonged prey suppression by carnivores - predator-removal experiments.

Oecologia 1989 Mar;78(4):458-467

Division of Wildlife and Ecology, CSIRO, P.O. Box 84, 2606, Lyneham, Canberra, Australia.

The hypothesis that carnivores can significantly suppress prey populations after they collapse during drought was tested by predator-removal experiments. Low populations of rabbits (Oryctolagus cuniculus) responded with significantly accelerated growth where foxes (Vulpes vulpes) and feral cats (Felis catus) were continually shot. Experiments in years of good pasture and poor were confirmatory. After only 14 months, the rabbits were well on their way to another eruption whereas untreated populations had remained low for 2.5 yrs until a second drought. These studies confirm the impact of carnivores found for low populations of cyclical prey but there was no measurable effect of predator-removal on the population declines in our studies. They were due to aridity and poor pastures. The concept of Environmentally Modulated Predation is presented. Only after the intervention of a widespread environmental event is such limiting predation possible. Drought is also the cause in arid Australia for dingoes (Canis familiaris dingo) preying seqenntially on rodents, rabbits and red kangaroos, while wildfire was the cause in temperate forests. Such environmental intervention may be more widespread than usually considered, triggering some apparent predator-prey cycles. The major factors limiting rabbits in inland Australia are: adequacy of green herbage during breeding, food scarcity during average summers, critical shortages of food and its low quality (including moisture content) during 'crashes' in drought, followed by limiting predation. Contrasting life-histories are one cause for the ultimate escape of rabbit populations from limiting predation as rabbits can breed continuously but carnivores seasonally only. Patchy predation and alternate prey may also play a part.
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http://dx.doi.org/10.1007/BF00378734DOI Listing
March 1989

Effect of gonadectomy, season and the presence of female tammar wallabies (Macropus eugenii) on concentrations of testosterone, luteinizing hormone and follicle-stimulating hormone in the plasma of male tammar wallabies.

J Endocrinol 1980 Jul;86(1):25-33

Concentrations of FSH, LH and testosterone in plasma were measured in groups of adult male tammar wallabies before and after gonadectomy, and during the breeding and non-breeding seasons. Gonadectomy resulted in a rapid fall in plasma testosterone to undetectable levels by day 2, and significant increases in plasma LH and FSH levels. The concentrations of FSH, LH and testosterone did not change significantly between the non-breeding and breeding seasons in groups of male wallabies maintained in the absence of females. However, when male wallabies were associated with sexually mature females there were significant three- to fourfold increases in concentrations of LH and testosterone in plasma at the commencement of the breeding season. The observed increases in LH and testosterone were highly synchronized in the eight animals studied and occurred approximately 2 weeks before the synchronous onset of mating. Concentrations of FSH did not change significantly at this time.
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http://dx.doi.org/10.1677/joe.0.0860025DOI Listing
July 1980
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