Search results for "stick"
showing 10 items of 58 documents
Cannibalism facilitates gigantism in a nine-spined stickleback (Pungitius pungitius) population
2016
Cannibalism is a taxonomically widespread phenomenon that can fundamentally affect the structure and stability of aquatic communities, including the emergence of a bimodal size distribution (“dwarfs” and “giants”) in fish populations. Emergence of giants could also be driven or facilitated by parasites that divert host resources from reproduction to growth. We studied the trophic ecology of giant nine-spined sticklebacks (Pungitius pungitius) in a Finnish pond to evaluate the hypotheses that gigantism in this population would be facilitated by cannibalism and/or parasitic infections by Schistocephalus pungitii cestode. Stomach content analyses revealed an initial ontogenetic dietary shift f…
Community structure affects trophic ontogeny in a predatory fish.
2016
While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. …
Large differences in catch per unit of effort between two minnow trap models
2013
Background: Little is known about variation in catch per unit of effort (CPUE) in stickleback fisheries, or the factors explaining this variation. We investigated how nine-spined stickleback (Pungitius pungitius) CPUE was influenced by trap model by comparing the CPUEs of two very similar minnow trap models fished side-by-side in a paired experimental design. Results: The galvanized trap type (mean CPUE = 1.31 fish h–1) out-fished the black trap type (mean CPUE = 0.20 fish h–1) consistently, and yielded on average 81% more fish. Conclusions: The results demonstrate that small differences in trap appearance can have large impacts on CPUE. This has implications for studies designed to investi…
Water temperature, not fish morph, determines parasite infections of sympatric Icelandic threespine sticklebacks (Gasterosteus aculeatus)
2013
Parasite communities of fishes are known to respond directly to the abiotic environment of the host, for example, to water quality and water temperature. Biotic factors are also important as they affect the exposure profile through heterogeneities in parasite distribution in the environment. Parasites in a particular environment may pose a strong selection on fish. For example, ecological differences in selection by parasites have been hypothesized to facilitate evolutionary differentiation of freshwater fish morphs specializing on different food types. However, as parasites may also respond directly to abiotic environment the parasite risk does not depend only on biotic features of the hos…
Study of lip hydration with application of photoprotective lipstick : influence of skin phototype, size of lips, age, sex and smoking habits
2009
Objectives: To study lip hydration levels when applying a lipstick sunscreen for 3 months and to evaluate the influence of size of lips, age, sex, smoking and skin phototype. Study design: The study group was formed by 140 volunteer subjects, one group consisting of 70 patients applying a commercial lipstick sunscreen three times a day and the other group of 70 controls in which no product was applied. The age range was 20-86 years. The influence in lip hydration levels of age, sex, phototype, size of the lips and smoking habits was studied using a Corneometer 825® (Courage and Khazaka Electronic GmbH, Cologne, Germany). Results: An increase in lip hydration was found between the basal (53.…
Determination of butyl methoxydibenzoylmethane, benzophenone-3, octyl dimethyl PABA and octyl methoxycinnamate in lipsticks.
2003
The complex composition of lipstick formulations usually needs the use of organic solvents for sample dissolution. A treatment based on dissolution of cosmetic samples in ethanol-water (70 : 30, v/v) by use of ultrasonic irradiation is proposed. A C(18) stationary phase and an isocratic mobile phase of ethanol:water:acetic acid (70 : 29.5 : 0.5, v/v/v) with a flow rate of 1 mL min(-1) and an injection volume of 20 microL is proposed for the high-pressure liquid chromatography (HPLC) determination of four UV-filters, and detection was carried out at 309 nm. The limit of the chromatographic detection was 7.0 microg mL(-1) for butyl methoxydibenzoylmethane, 1.5 microg mL(-1) for benzophenone-3…
A noodle, hockey stick, and spaghetti plate: a perspective on high‐resolution paleoclimatology
2010
The high-resolution reconstruction of hemispheric-scale temperature variation over the past-millennium benchmarks recent warming against more naturally driven climate episodes, such as the Little Ice Age and the Medieval Warm Period, thereby allowing assessment of the relative efficacies of natural and anthropogenic forcing factors. Icons of past temperature variability, as featured in the Intergovernmental Panel on Climate Change (IPCC) reports over nearly two decades, have changed from a schematic sketch in 1990, to a seemingly well-solved story in 2001, to more explicit recognition of significant uncertainties in 2007. In this article, we detail the beginning of the movement to reconstru…
Reforms and decentralization: friends or foes
2013
Systemic concerns about markets, capitalism and the role of the state in the economy are salient again. Relatively large-scale reforms of economic and social arrangements are seriously considered. Historical experience suggests that reforms of that kind are sometimes associated with important changes in institutional arrangements pertaining to political decentralization. To explore the relationship between economic reforms and decentralization, the paper argues that a reform has two dimensions. It is a process and it is a design. The organization of the paper is inspired by that distinction. For economists, it seems natural to reason in terms of design -- that is, to perceive reform as the …
Political Yardstick Competition and Corporate Governance in the European Union
2006
http://www.dur.ac.uk/john.ashworth/EPCS/Papers_and_Authors.php; The question whether regulatory competition in the area of company law could take place in the European Union (EU) in a way similar to the form it takes in the United States (the Delaware phenomenon) is topical because of some recent judgments of the European Court of Justice (Centros) and documents and projects produced by the European Commission. That question is typically discussed, however, as if voters did not count and as if competition among governments was exclusively based on the mobility of firms across jurisdictions. But intergovernmental competition can also take the form of yardstick, or relative performance, compe…
Decentralization as an incentive scheme when regional differences are large
2010
It has been suggested that large regional differences could be an obstacle to that part of the political accountability of office-holders which is based on yardstick competition among governments. The paper addresses that question and concludes that the obstacle is not too serious in general. The second part of the paper is devoted to the persistent economic underperformance of some regions in countries such as Germany, Italy and (with regard to regions overseas) France. How is it that the mechanism of yardstick competition induces a convergence of economic performance among European Union member countries, even those particularly poor initially, but fails to induce all the underperforming …