Effects of algal turbidity on foraging and antipredator behaviour of the three-spined stickleback (Gasterosteus aculeatus)

The aim of this thesis was to examine how aquatic organisms, such as fish, behave in an altered environmental condition. Many species of fish use vision as their primary tool to gain information about their surrounding environment. The visual conditions of aquatic habitats are often altered as a result of anthropogenic disturbance, such as eutrophication that initiates algal turbidity. In general, turbidity reduces the visibility and can be hypothesized to have an influence on the behaviour of fish. I used the three-spined stickleback (Gasterosteus aculeatus) as a model species and conducted four studies in the laboratory to test how algal turbidity affects its behaviour. In this thesis, two major behavioural aspects are discussed. The first is antipredator behaviour. In study I, the combined effects of turbidity and shoot density on habitat choice (shelter vs open) behaviour was tested on a group of sticklebacks (20 fish) in the presence and absence of piscivorous perch (Perca fluviatilis). In study II, I examined the behavioural responses of feeding sticklebacks when they were exposed to the sudden appearance of an avian predator (the silhouette of a common tern, Sterna hirundo). The study was done in turbid and clear water using three different groups sizes (1, 3 and 6 fish). The second aspect is foraging behaviour. Study III & IV focused on the effects of algal turbidity on the foraging performance of sticklebacks. In study III, I conducted two separate experiments to examine the effects of turbidity on prey consumption and prey choice of sticklebacks. In this experiment turbidity levels and the proportion of large and small prey (Daphnia spp.) were manipulated. In study IV, I studied whether a group of six sticklebacks can distribute themselves according to food input at two feeding stations in a way that provided each fish with the same amount of food in clear and turbid water. I also observed whether the fish can follow changes in resource distribution between the foraging patches. My results indicate an overall influence of algal turbidity on the antipredator and foraging behaviour of sticklebacks. In the presence of a potential predator, the use of the sheltered habitat was more pronounced at higher turbidity. Besides this, sticklebacks reduced their activity levels with predator presence at higher turbidity and shoot density levels, suggesting a possible antipredator adaptation to avoid a predator. When exposed to a sudden appearance of an avian predator, sticklebacks showed a weaker antipredator response in turbid water, which suggests that turbidity degrades the risk assessment capabilities of sticklebacks. I found an effect of group size but not turbidity in the proportion of sticklebacks that fled to the shelter area, which indicates that sticklebacks are able to communicate among group members at the experimental turbidity levels. I found an overall negative effect of turbidity on food intake. Both turbidity and changes in the proportion of prey sizes played a significant role in a stickleback’s prey selection. At lower turbidity levels (clear <1 and 5 NTU) sticklebacks showed preferences for large prey, whereas in more turbid conditions and when the proportion of large to small prey increased sticklebacks became increasingly random in their prey selection. Finally, my results showed that groups of sticklebacks disperse themselves between feeding stations according to the reward ratios following the predictions of the ideal free distribution theory. However, they took a significantly longer time to reach the equilibrium distribution in turbid water than in clear water. In addition, they showed a slower response to changes in resource distribution in a turbid environment. These findings suggest that turbidity interferes with the information transfer among group foragers. It is important to understand that aquatic animals are often exposed to a degraded environment. The findings of this thesis suggest that algal turbidity negatively affects their behavioural performance. The results also shed light on the underlying behavioural strategies of sticklebacks in turbid conditions that might help them adapt to an altered environmental situation and increase their survival. In conclusion, I hold that although algal turbidity has detrimental effects on the antipredator and foraging behaviour of sticklebacks, their behavioural adjustment might help them adapt to a changing environment.

Cost-plus-loss analyses of forest inventory strategies based on kNN-assigned reference sample plot data

Abstract

Growth strategies of international companies in the emerging markets of South-East Europe

Työn tarkoituksena oli tutkia niitä tekijöitä jotka ovat vaikuttaneet kansainvälisten yritysten myynnin kasvuun Romaniassa, Bulgariassa, Serbiassa ja Sloveniassa. Tutkimusta varten haastateltiin neljää kansainvälisen yrityksen edustajaa sekä 16 kansainvälisen kaupan ammattilaista. Työn akateemisena viitekehyksenä käytettiin keskeisiä kansainvälisen liiketoiminnan teorioita sekä myynnin strategista viitekehystä. Johtopäätöksenä katsotaan, että menestyvillä yrityksillä on selvä kansainvälistymis-strategia, kansainvälinen organisaatio, konsultoiva myyntityyli ja resursseja investoida koulutukseen. Tarkastelun alla olevista maista etenkin Romaniasta ja Bulgarista löytyy liiketoiminta potentiaalia. Tutkimuksen johtopäätökset perustuvat laadullisiin ja määrällisiin tutkimusmenetelmiin ja ne on tarkoitettu palvemaan Tikkurila Oy:tä. Tutkimustuloksia on myös mahdollista soveltaa laajemmin samanlaisessa tutkimusympäristössä, kunhan tutkittavan liiketoimintaympäristön erityispiirteet ovat otetttu huomioon

The Effectiveness of Currency Hedging Strategies. Case: Imatra Boards Business Unit of Stora Enso Corp.

Tutkimus tarkastelee vaihtoehtoisia termiinisuojaustrategioita metsäteollisuuden alan tulosyksikössä. Jälkitestauksen tarkoituksena on arvioida vaihtoehtoisten strategioiden tuloksellisuutta suojata case-yrityksen kassavirtoja seuraavan kolmen arviointikriteerin avulla: yksittäisten vieraan valuutan määräisten kassavirtojen vaihtelu; koko vieraan valuutan määräisen kassavirran vaihtelu; suojausvoitot ja -tappiot. Tutkimuksen teoreettinen viitekehys tarkastelee yrityksen päätöksentekoa, valuuttariskien suojausprosessia sekä esittelee yrityksen vaihtoehtoisia suojausstrategioita. Tutkimuksen empiirinen aineisto pohjautuu case- yrityksen historiallisiin myyntilukuihin ja on kerätty yrityksen tietojärjestelmästä. Muu tutkimuksessa käytetty dataon kerätty eri tietokannoista. Tutkimuksen tulokset osoittavat, että suojaaminen vähentää kassavirtojen vaihtelua. Suojaamisen taloudelliset tulokset ovat kuitenkin erittäin riippuvaisia valitusta suojausstrategiasta, joka voi johtaa merkittäviin suojausvoittoihin, mutta yhtä hyvin myos merkittäviin tappioihin. Johdon näkemykset ja riskitoleranssi määrittelevät mitä strategiaa yrityksessä tullaan viime kädessä noudattamaan.

Magazine publishers and their online strategies

It seems as if magazine publishers have only haphazardly listed multiple goals for their websites, and have not carefully reflectedon how to achieve them. We present a framework for defining a magazine's onlinestrategy based on previous studies and on secondary data from the industry. We identify three steps in the strategy process. The first is to determine whether the magazine would actually benefit from online presence: although most magazines will never make money from their websites, a web presence may still be justified. The second step is to choose an optimal online strategy that matches the magazine's competitive strategy. Finally, we argue that magazine publishers should carefully consider to what extent they should allow their readers to be involvedin the web pages. This interactivity could be seen as a key factor in exploiting the unique nature of the Internet. It is our understanding that virtual communities could, at best, be a way of creating more value for a magazine's readers, advertisers and editors, alike. We formulate a typology of five different onlinebusiness concepts for magazines based on these three strategic steps.

Effects of winter feeding strategies with alternative feeds on the performance of mature suckler cows and their progeny

Selostus: Tasaruokinnan ja vaihtoehtoisten rehujen soveltuvuus emolehmien talvikauden ruokintaan

On Market Entry Strategies to France, Italy and Spain – The Finnish Information and Communication Technologies Sector

Tutkielman tavoitteena oli tarkastella markkinoillemenostrategian valitsemista Ranskan, Italian ja Espanjan Informaatio- ja kommunikaatioteknologioiden markkinoille (pääpainon ollessa Ranskassa). Tutkielman empiiristä osaa varten tehtiin sarja haastatteluja. Niistä saatuja tuloksia verrattiin kirjallisuudesta saatuihin tietoihin. Kirjallisuuden ja haastattelujen avulla pyrittiin tuomaan esille uutta tietoa joka voisi auttaa suomalaisyrityksiä heidän suunnitellessa markkinoillemenoa. Suomalaisten ICT-alan yritysten suurimmat ongelmat kohdemarkkinoille markkinoillemenoprosessissa johtuvat kulttuurieroista ja byrokratiasta. Markkinoillemenomuodon valinnassa haluttiinkin haastatteluissa painottaa paikallisten työntekijöiden ja kumppaneiden käyttöä. Lisäksi kaivattiin suomalaisyritysten välistä parempaa yhteistyötä.

International Growth Strategies of Small and Medium-Sized Enterprises in Infocom Sector

Tutkimuksen päätavoite on selvitää infocom-toimialan pk-yritysten kansainväliset kasvustrategiat. Aluksi on tarkasteltu kasvua edesauttaneita ja hidastaneita tekijöitä, jotka muodostavat pohjan kansainvälisen kasvun suunnittelulle. Näiden pohjalta on aikaisemmin esitettyihin teoriamalleihin ja yritysten kansainvälistymisen asteeseen yhdistettynä määritelty infocom-toimialan pk-yrityksten kansainväliset kasvustrategiavaihtoehdot. Tutkimuksen tarkasteluun on vaikuttanut born global-ilmiö, jonka pääpiirre on nopea kansainvälistyminen yrityksen aikaisessa kehitysvaiheessa. Työn empiirisessä osassa on havainnollistettu teoriassa käsiteltyjä kansainväliseen kasvuun liittyviä tekijöitä. Empiirisessä osassa on käytetty sekä kvantitatiivisia että kvalitatiivisia menetelmiä. Kvantitatiivinen survey tutkimus on pohjautunut aineistoon, joka on kerätty vuosina 1999-2000 Telecom Business Research Centerissä Lappeenrannassa. Kvalitatiivisessa case-tutkimuksessa on haastateltu infocom-toimialan pk-yrityksiä. Nopeasti kehittyvän infocom-toimialan pk-yrityksille kansainvälistyminen on haaste ja tärkein menestyksen edellytys. Pk-yritysten kasvuresurssit ovat rajalliset, mutta lisääntyvän verkostoitumisen myötä on yritysten välisestä yhteistyöstä saavutettu etuja, jotka ovat mahdollistaneet kansainvälisen kasvun. Markkinoiden muutosnopeus on suuri ja siksi strategisen suunnittelun aikaväli lyhenee. Kansainvälisiä kasvustrategioita muodostettaessa yritykset joutuvat samanaikaisesti turvautumaan useampaan eri kasvustrategiaan, joiden yhdistelmänä yritysten merkittävimmäksi kasvustrategiaksi muodostuvat hybridit kasvustrategiat.

Impact of Investment Strategies on Performance in Pulp and Paper Industry

The main objective of this study was to examine, what kind of investment strategies the leading European and North American pulp and paper industry companies (PPI) used in 1991-2003, and how the selected strategies affected their performance. The investment strategies were categorised in three classes including mergers and acquisitions, investments in new capacity and investments in existing capacity. The results showed that mergers and acquisitions represented the largest share of total investments in 1991-2003 followed by investments in existing capacity. PPI companies changed investment strategies over time by increasing the share of mergers and acquisitions, which decreased investments in new capacity especially among North American companies. According to the results, good asset quality and investments in new and existing capacity provided better profitability than often expensive acquisitions. Also the capacity decreases had a positive impact on profitability. Average asset quality and profitability were higher among European companies. The study concluded that in the long term the available value creating investment opportunities should limit capital expenditure levels, not the relation of capital expenditure to depreciation.

Growth Strategies in Pulp and Paper Industry: An Empirical Investigation on Profitability Effects

This study investigates whether there are differences in profitability of PPI companies based on the growth strategy they have chosen to follow. It is examined whether those companies following organic growth strategy are more profitable than those companies following acquisitive growth strategy. It is also investigated are ones larger than the others, or are ones growing faster than the others. Also, the factors affecting the profitability of acquisitive companies are further examined. The results showed that there actually are differences between the two groups. Organically grown companies were found to be more profitable, smaller and growing slower than acquisitive companies. When it comes to examining only acquisitive companies there could be found factors that better or worsen the profitability of companies. For example targets that the company has bought in developing markets were making them more profitable.

Merchandising Strategies and Retail Performance for Seasonal Fashion Products

This study presents mathematical methods for evaluation of retail performance with special regard to product sourcing strategies. Forecast accuracy, process lead time, offshore / local sourcing mix and up front / replenishment buying mix are defined as critical success factors in connection with sourcing seasonal products with a fashion content. As success measures, this research focuses on service level, lost sales, product substitute percentage, gross margin, gross margin return on inventory and mark down rate. The accuracy of demand forecast is found to be a fundamental success factor. Forecast accuracy depends on lead time. Lead times are traditionally long and buying decisions are made seven to eight months prior to the start of the selling season. Forecast errors cause stockouts and lost sales. Some of the products bought for the selling season will not be sold and have to be marked down and sold at clearance, causing loss of gross margin. Gross margin percentage is not the best tool for evaluating sourcing decisions and in the context of this study gross margin return on inventory, which combines profitability and assets management, is used. The findings of this research suggest that there are more profitable ways of sourcing products than buying them from low cost offshore sources. Mixing up front and inseason replenishment deliveries, especially when point of sale information is used for improving forecast accuracy, results in better retail performance. Quick Response and Vendor Managed Inventory strategies yield better results than traditional up front buying from offshore even if local purchase prices are higher. Increasing the number of selling seasons, slight over buying for the season in order to