Search results for "laji"
showing 10 items of 410 documents
Spatiotemporal and gender-specific parasitism in two species of gobiid fish
2018
Parasitism is considered a major selective force in natural host populations. Infections can decrease host condition and vigour, and potentially influence, for example, host population dynamics and behavior such as mate choice. We studied parasite infections of two common marine fish species, the sand goby (Pomatoschistus minutus) and the common goby (Pomatoschistus microps), in the brackish water Northern Baltic Sea. We were particularly interested in the occurrence of parasite taxa located in central sensory organs, such as eyes, potentially affecting fish behavior and mate choice. We found that both fish species harbored parasite communities dominated by taxa transmitted to fish through …
Talent identification in soccer using a one-class support vector machine
2019
Abstract Identifying potential future elite athletes is important in many sporting events. The successful identification of potential future elite athletes at an early age would help to provide high-quality coaching and training environments in which to optimize their development. However, a large variety of different skills and qualities are needed to succeed in elite sports, making talent identification generally a complex and multifaceted problem. Due to the rarity of elite athletes, datasets are inherently imbalanced, making classical statistical inference difficult. Therefore, we approach talent identification as an anomaly detection problem. We trained a nonlinear one-class support ve…
Generalist invasion in a complex lake food web
2023
Invasive species constitute a threat not only to native populations but also to the structure and functioning of entire food webs. Despite being considered as a global problem, only a small number of studies have quantitatively predicted the food web-level consequences of invasions. Here, we use an allometric trophic network model parameterized using empirical data on species body masses and feeding interactions to predict the effects of a possible invasion of Amur sleeper (Perccottus glenii), on a well-studied lake ecosystem. We show that the modeled establishment of Amur sleeper decreased the biomasses o ftop predator fishes by about 10%–19%. These reductions were largely explained by inc…
Poison frog social behaviour under global change: potential impacts and future challenges
2022
AbstractThe current and cascading effects of global change challenges the interactions both between animal individuals (i.e. social and sexual behaviour) and the environment they inhabit. Amphibians are an ecologically diverse class with a wide range of social and sexual behaviours, making them a compelling model to understand the potential adaptations of animals faced with the effects of human-induced rapid environmental changes (HIREC). Poison frogs (Dendrobatoidea) are a particularly interesting system, as they display diverse social behaviours that are shaped by conspecific and environmental interactions, thus offering a tractable system to investigate how closely related species may re…
‘Strong and courageous’ but ‘constantly insecure’: dialogical self theory, intersecting identities, and Christian mixed martial arts
2021
Being a mixed martial arts fighter and a devout Christian seems to present an apparent contradiction that requires identity work to bring these identities into unity. We used Dialogical Self Theory and explored the autobiography of Ron ‘H2O’ Waterman, a professional fighter turned evangelist, to understand how the tensions between the different identities or I-positions were negotiated. We identified two I-positions, ‘Ron the Fighter’ and ‘Ron the Pater Familias’, which related differently to religion, sport, and masculinity. Importantly, the negotiations were not between MMA and faith, but between these two I-positions that served the different needs for self-enhancement and union with som…
Nutrition Knowledge Is Associated with Energy Availability and Carbohydrate Intake in Young Female Cross-Country Skiers
2021
The aim of this study was to provide information on energy availability (EA), macronutrient intake, nutritional periodization practices, and nutrition knowledge in young female cross-country skiers. A total of 19 skiers filled in weighted food and training logs before and during a training camp. Nutrition knowledge was assessed via a validated questionnaire. EA was optimal in 11% of athletes at home (mean 33.7 ± 9.6 kcal·kgFFM−1·d−1) and in 42% at camp (mean 40.3 ± 17.3 kcal·kgFFM−1·d−1). Most athletes (74%) failed to meet recommendations for carbohydrate intake at home (mean 5.0 ± 1.2 g·kg−1·d−1) and 63% failed to do so at camp (mean 7.1 ± 1.6 g·kg−1·d−1). The lower threshold of the pre-ex…
Impacts of piscicide-induced fish removal on resource use and trophic diversity of lake invertebrates
2022
Chemical eradication of non-native species has become a widely used method to mitigate the potential negative im- pacts of altered competitive or predatory dynamics on biodiversity and natural ecosystem processes. However, the re- sponses of non-target species can vary from rapid full recovery to delayed or absent recolonization, and little is known about the potential shifts in resource use and trophic diversity of native species following chemical treatments. We used a before-after-control-impact approach to study the effects of rotenone piscicide treatment on abundance and tro- phic niche of benthic invertebrates in three untreated and three treated lakes in central Norway, the latter gr…
Täpläravun (Pacifastacus leniusculus) vaikutus ahventen (Perca fluviatilis) loisyhteisöihin Päijänteellä
2010
Täplärapu (Pacifastacus leniusculus) on tulokaslaji Suomen vesistöissä. Sen on käyttäytymisellään ja ravinnonkäytöllään todettu vähentävän elinalueidensa eliöyhteisöjen monimuotoisuutta. Esimerkiksi Päijänteellä on havaittu joidenkin pohjaeläinten kuten kotiloiden tiheyksien olevan alhaisempia ravun elinalueilla kuin ravuttomilla alueilla. Pohjaselkärangattomat ovat välttämättömiä väli-isäntiä monelle kalan loiselle. Tässä tutkimuksessa selvitettiin, millaisia muutoksia täplärapu voi välillisesti aiheuttaa kalojen loisyhteisöissä muuttamalla pohjaeläinten runsautta. Päijänteeltä valittiin viisi toisistaan riippumatonta ravullista ja ravutonta aluetta. Jokaiselta alueelta pyydettiin mahdolli…
The effect of environmental fluctuations on the invasion success of bacterial invader Serratia marcescens
2017
Ilmastonmuutoksen on odotettu lisäävän ympäristöolosuhteissa tapahtuvien vaihteluiden määrää. Teorian mukaan nämä vaihtelut voisivat lisätä vieraslajien levittäytymistä uusille alueille, mikäli ne vaikuttavat ekologisiin ja evolutiivisiin prosesseihin, jotka tekevät lajeista menestyksekkäitä vieraslajeja sekä paikallisista eliöyhteisöistä ja ympäristöistä alttiimpia levittäytymiselle. Häiriöherkkien alueiden on oletettu olevan otollisia levittäytymiselle, minkä lisäksi vieraslajit ovat voineet valmiiksi sopeutua sietämään vaihtelevia olosuhteita alkuperäisalueellaan. Nopeasti vaihtelevissa ympäristöolosuhteissa luonnonvalinta voi suosia ominaisuuksia, kuten generalismia, joka auttaa eliöitä…