Search results for "lämpötila"

Keväinen lämpeneminen ja jääpeitteen alaiset veden liikkeet Päijänteen Ristinselällä 2006

2007

Effects of temperature and feeding regime on compensatory growth of rainbow trout, Oncorhynchus mykiss

2006

Automated water quality monitoring of humic lakes by using the optical properties of water

2016

Automated water quality monitoring (AWQM) is becoming increasingly common in lakes worldwide. The history of AWQM is relatively short and standard calibration procedures for the measured variables are largely yet to be established. The use of optical AWQM sensors, developed in oceanic environments, raises new questions on the diverse effects which humic compounds may have on the automated optical measurements in inlands waters. The focus of this thesis was to characterize the effects of coloured dissolved organic matter (CDOM) on optical in situ measurements of organic matter (OM) and chlorophyll (Chl) in lakes with varying humic content, and to use AWQM data as a part of traditional monito…

Variation in Hsp70 levels after cold shock: Signs of evolutionary responses to thermal selection among Leptinotarsa decemlineata populations

2012

Individuals of widely spread species are expected to show local adaption in temperature tolerance as they encounter a range of thermal conditions. We tracked thermal adaptations of the Colorado potato beetle (Leptinotarsa decemlineata) that invaded Europe within the last 100 years. It has occupied various conditions although, like the majority of invasive species, it lost a measurable amount of neutral genetic variation due to bottleneck effect when it invaded Europe. We exposed diapausing beetles originated from three different latitudes (54°N, 59°N, 60°N) to cold shock (−5°C, 1.5 hrs) in order to test if beetles from the northern populations express differential levels of cold-induced and…

Temperature effects explain continental scale distribution of cyanobacterial toxins

2018

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect…

The effect of temperature on cercariae production of two Rhipidocotyle trematodes parasitizing freshwater mussel, Anodonta anatina.

2013

Two bucephalid trematodes, Rhipidocotyle campanula and R. fennica are known to infect the duck mussel, Anodonta anatina. The infection will lead to decrease growth, reproduction and survival of A. anatina. Given the important role of temperature on cercariae production, a vital component of the parasite’s transmission and life cycle success, the effect of temperature on cercariae production of two Rhipidocotyle sp. in their molluscan host, Anodonta anatina, was investigated. Mussels were collected from the Rivers, Haajaistenjoki and Kuusaankoski, marked and allocated to three temperature treatments—high, intermediate and low. Between May 31-October 28, 2011, clams were individually monitore…

Termodynaaminen tasapainotila ja lämpöopin pääsäännöt lukio-opetuksessa

2009

Tässä tutkielmassa perehdyttiin lukiolaisten käsityksiin termodynaamisesta tasapainotilasta sekä lämpöopin ensimmäisestä ja toisesta pääsäännöstä. Tasapainotilan käsite on fysiikan tietorakenteen hierarkiassa korkealla, mutta tästä huolimatta nuorten käsityksiä siihen liittyen on tutkittu vain vähän. Ensimmäisen ja toisen pääsäännön ymmärtäminen sekä niiden soveltaminen on havaittu aiempien tutkimusten mukaan ongelmalliseksi vielä korkeakoulutasollakin. Tutkimus suoritettiin oppikirja-analyysin ja oppilaskyselyn avulla. Oppikirja-analyysiss ä tutkittiin kahta Suomen lukioissa käytettävää oppikirjaa, Tammen kustantamaa Fysiikka-kirjaa sekä WSOY:n kustantamaa Physica-kirjaa. Analyysin tavoitt…

The “Seili-index” For The Prediction of Chlorophyll-α Levels In The Archipelago Sea of The Northern Baltic Sea, Southwest Finland

2021

AbstractTo build a forecasting tool for the state of eutrophication in the Archipelago Sea, we fitted a Generalized Additive Mixed Model (GAMM) to marine environmental monitoring data, which were collected over the years 2011–2019 by an automated profiling buoy at the Seili ODAS-station. The resulting “Seili-index” can be used to predict the chlorophyll-α (chl-a) concentration in the seawater a number of days ahead by using the temperature forecast as a covariate. An array of test predictions with two separate models on the 2019 data set showed that the index is adept at predicting the amount of chl-a especially in the upper water layer. The visualization with 10 days of chl-a level predict…

Divergent temperature-specific metabolic and feeding rates of native and invasive crayfish

2022

Temperature is one of the most important factors governing the activity of ectothermic species, and it plays an important but less studied role in the manifestation of invasive species impacts. In this study, we investigated temperature-specific feeding and metabolic rates of invasive and native crayfish, and evaluated how temperature regulates their ecological impacts at present and in future according to different climatic scenarios by bioenergetics modelling. We conducted a series of maximum food consumption experiments and measured the metabolic rates of cold-adapted native noble crayfish (Astacus astacus) and invasive signal crayfish (Pacifastacus leniusculus) originally from a warmer …

Studies of transition-edge sensor physics : thermal models and noise

2011

This thesis focuses on studying the noise in transition-edge sensors (TES). More specifically, the aim is to find an explanation for the observed excess noise that is limiting their performance and has been troubling the TES field in recent years. Several theories have been put forth but a definitive answer is still missing. In the early stages of this thesis work a novel theory was presented for the noise in a special TES geometry. In our theory the excess noise is caused by correlated fluctuations of superconductivity at the phase boundary between normal and superconducting states. Data from more recent experiments does not give solid support for the theory and in this thesis the validity…