Browsing Biology by Title
Now showing items 133-152 of 228
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Natural Selection, Variation, Adaptation, and Evolution: a Primer of Interrelated Concepts
(2010-11)Natural selection is an elegantly simple concept but one that can manifest in complex ways. I review how the basic model of single-trait viability selection has been extended to more complex forms of selection on multiple ... -
Non-linear genetic isolation by distance: implications for dispersal estimation in anadromous and marine fish populations
(2007)Indirect genetic approaches such as those based on the association between genetic and geographic distance (isolation by distance, IBD) may provide one of the best means of estimating dispersal in marine systems. We ... -
Non-Occurrence of Free-Living Paramoeba-Invadens in Water and Sediments of Halifax Harbour Nova Scotia Canada
(1989)Seawater and sediment samples from various sites in or near Halifax Harbour were cultured for Paramoeba as were tissues of the natural sea urchin host Stronglyocentrotus droebachiensis sampled from Halifax Harbour. An ... -
Nonbreeding-Season Drivers of Population Dynamics in Seasonal Migrants: Conservation Parallels Across Taxa
(2009-12)For seasonal migrants, logistical constraints have often limited conservation efforts to improving survival and reproduction during the breeding season only. Yet, mounting empirical evidence suggests that events occurring ... -
A note on the Aristotelian origin of Popper's demarcation criterion together with its application to Atlantic Canada's fisheries
(2012-03-26)It has not always been realised that Karl Popper's demarcation criterion, the criterion he uses to distinguish an empirical science from its 'metaphysical' complement involves an interpretation of the classical theory of ... -
Nucleotide sequence of 5S rDNA and localization of the ribosomal RNA genes to metaphase chromosomes of the Tilapiine cichlid fish, Oreochromis niloticus
(2000-10)In this study, we report the cloning and nucleotide sequence of PCR-generated 5S rDNA from the Tilapiine cichlid fish, Oreochromis niloticus. Two types of 5S rDNA were detected that differed by insertions and/or deletions ... -
Nucleotide sequence, genomic organization and evolution of a major repetitive DNA family in tilapia (Oreochromis mossambicus/hornorum )
(1989)A highly repetitive DNA sequence from tilapia (Oreochromis mossambicus/hornorum ) has been cloned and sequenced. It is a tandemly arrayed sequence of 237 bp and constitutes 7% of the fish genome. The copy number of the ... -
The Oaks Experiments on Organic Management of Turf: Final Industry Report
(Edmonds Landscape and Construction Services Limited, Halifax, Nova Scotia, Canada., 1996-10-30)The Oaks experiments were designed to address practical questions about organic management of turfs (lawns, sports fields etc.), notably: (i) How do we use organic fertilizers and soil-building amendments on turf for maximum ... -
Observations on a mixed farm during the transition to biological husbandry
(2011-01-19)Tunwath is a mixed farm (laying hens-grains) located in the Annapolis Valley, Nova Scotia, in a cool humid temperate zone. It includes about 2100 laying hens, 35 hectares of field crops and additional garden, pasture, hay ... -
Observer Effects and Avian-Call-Count Survey Quality: Rare-Species Biases and Overconfidence
(2012-01)Wildlife monitoring surveys are prone to nondetection errors and false positives. To determine factors that affect the incidence of these errors, we built an Internet-based survey that simulated avian point counts, and ... -
On-farm measurements of pH, electrical conductivity and nitrate in soil extracts for monitoring coupling and decoupling of nutrient cycles
(Biological Agriculture & Horticulture, 1993) -
Otolith elemental composition and adult tagging reveal spawning site fidelity and estuarine dependency in rainbow smelt
(2008)Observations of homing and straying in marine organisms based on traditional Eulerian approaches may fail to resolve dispersal kernels or be unable to differentiate homing from invariant local residency, The roles of ... -
Overestimating Fish Counts by Non-Instantaneous Visual Censuses: Consequences for Population and Community Descriptions
(2010-07)Background: Increasingly, underwater visual censuses (UVC) are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into ... -
Oxygen transport in egg masses of the amphibians Rana sylvatica and Ambystoma maculatum: Convection, diffusion and oxygen production by algae
(1994)Many amphibians lay their eggs in gelatinous masses up to 10-20 cm in diameter, posing problems for diffusive oxygen delivery. Oxygen may also be provided by water convection between eggs or by oxygen production by endogenous ... -
Pacific Salmon in Hot Water: Applying Aerobic Scope Models and Biotelemetry to Predict the Success of Spawning Migrations
(University of Chicago Press, P.O. Box 37005 Chicago IL 60637 USA, [mailto:help@press.uchicago.edu], [URL:http://www.journals.uchicago.edu/], 2008-12)Concern over global climate change is widespread, but quantifying relationships between temperature change and animal fitness has been a challenge for scientists. Our approach to this challenge was to study migratory ... -
Patch Dynamics of a Phytophagous Mite Population Effect of Number of Subpopulations
(1991)I conducted a field test of the hypothesis that the dynamics of a predator-prey interaction should be affected by the number of interacting subpopulations within an assemblage. I used a "successful" biological control ... -
Phylogenomic analysis of natural selection pressure in Streptococcus genomes
(2007-08)Background: In comparative analyses of bacterial pathogens, it has been common practice to discriminate between two types of genes: (i) those shared by pathogens and their non-pathogenic relatives (core genes), and (ii) ... -
Physical and biological factors influencing mussel (Mytilus trossulus, M. edulis) settlement on a wave-exposed rocky shore
(1996)Settlement rates of mussels Mytilus trossulus and M. edulis on artificial collectors (aquarium filter wool) and natural substrata were measured in tidepools and on emergent rock in recently ice-scoured and non-scoured ... -
Polar Bear Diets and Arctic Marine Food Webs: Insights from Fatty Acid Analysis
(2008-11)We used quantitative fatty acid signature analysis (QFASA) to examine the diets of 1738 individual polar bears (Ursus maritimus) sampled across the Canadian Arctic over a 30-year span. Polar bear foraging varied over ... -
Pollen limitation of plant reproduction: Ecological and evolutionary causes and consequences
(2004-09)Determining whether seed production is pollen limited has been an area of intensive empirical study over the last two decades. Yet current evidence does not allow satisfactory assessment of the causes or consequences of ...