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Quantifying temporal changes in Tornionjoki river ice breakup dates and spring temperatures in Lapland since 1802

Journal of Geographical Sciences 2013年第6期23卷 1069-1079页

作者： Samuli HELAMA Jianmin JIANG Johanna KORHONEN Jari HOLOPAINEN mauri timonen Finnish Forest Research Institute Rovaniemi Northern Unit 96300 Finland Training Centre of China Meteorological Administration Beijing 100081 China Finnish Environment Institute Helsinki P.O. Box 140 00251 Finland Department of Geosciences and Geography University of Helsinki Helsinki P.O. Box 64 00014 Finland

Cryophenological records （i.e. observational series of freeze and breakup dates of ice） are of great importance when assessing the environmental variations in cold regions. Here we employed the extraordinarily long observational records of river ice breakup dates and air temperatures in northern Fennoscandia to examine their interrelations since 1802. Historical observations, along with modern data, comprise the informational setting for this analysis carried out using t-test. Temperature history of April-May season was used as cli- matic counterpart for the breakup timings. Both records （temperature and breakup） showed seven sub-periods during which their local means were distinctly different relative to preced- ing and subsequent sub-periods. The starting and ending years of these sub-periods oc- curred in temporal agreement. The main findings of this study are summarized as follows：（1） the synchrony between the temperature and river ice breakup records ruled out the possibility that the changes would have occurred due to quality of the historical series （i.e. inhomoge- neity problems often linked to historical time-series）; （2） the studied records agreed to show lower spring temperatures and later river ice breakups during the 19th century, in comparison to the 20th century conditions, evidencing the prevalence of cooler spring temperatures in the study region, in agreement with the concept of the Little Ice Age （1570-1900） climate in North-West Europe; （3） the most recent sub-period demonstrate the highest spring tem- peratures with concomitantly earliest river ice breakups, showing the relative warmth of the current springtime climate in the study region in the context of the past two centuries; （4） the effects of anthropogenic changes in the river environment （e.g. construction and demolition of dams） during the 20th century should be considered for non-climatic variations in the breakup records; （5） this study emphasizes the importance of multi-centurial （i.e. historical） cryo- phenological information fo

关键词： climatic change historical climatology Lapland Little Ice Age phenology

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Beyond successful and active ageing

Beyond successful and active ageing

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作者： timonen Virpi

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Collaborative Consumption as a Source of Market Disruption

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Management Studies 2019年第1期7卷 33-41页

作者： Petteri Repo Paivi timonen University of Helsinki HelsinkiFinland

The concept of collaborative consumption has been developed in consumer studies to define new consumption opportunities which are facilitated by information systems.Accordingly,novel services such as the ridesharing service Uber,for transport,and the hospitality-brokering service Airbnb,for accommodation,successfully employ collaboration in consumption and provide consumers with novel types of access to services.Yet while the identification of this new characteristic of consumption is of great merit,less attention has been paid in consumer studies to how it challenges existing market arrangements.It is against this background that this article examines collaborative consumption as a source of market disruption.The article applies the concept to the empirical case of a pilot scheme in collaborative public transport(Kutsuplus),which essentially consisted of a taxi-like bus service in Helsinki,Finland.It argues that collaborative consumption may tend to contribute premium rather than standard quality in public services,which is apt to disrupt both public and private service markets.The analysis further affirms that the concept of collaborative consumption is well suited to the assessment of novel services and their disruptive characteristics.

关键词： collaborative consumption consumer studies market disruption public and private services transport

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Sustainable Futures： Comparing Methodologies for Analyzing Citizen Visions in Europe

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Journal of Sociology Study 2017年第5期7卷 246-262页

作者： Petteri Repo Kaisa Matschoss Paivi timonen University of Helsinki Finland

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Stimulating brain tissue with bright light alters functional connectivity in brain at the resting state

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World Journal of Neuroscience 2012年第2期2卷 81-90页

作者： Tuomo Starck Juuso Nissila Antti Aunio Ahmed Abou-Elseoud Jukka Remes Juha Nikkinen Markku timonen Timo Takala Osmo Tervonen Vesa Kiviniemi Department of Diagnostic Radiology Oulu University HospitalOuluFinland Department of Diagnostic Radiology University of OuluOuluFinland Valkee Ltd. OulunsaloFinland Department of Biology University of OuluOuluFinland Institute of Health Sciences(General Practise) University of OuluOuluFinland Department of Electrical and Information Engineering University of OuluOuluFinland Oulu Deaconess Institute OuluFinland

Light is considered to modulate human brain function only via the retinal pathway, a way of thinking that we aimed to challenge in the present study. Literature provides evidence of inherent phototransduction for instance in the rat brain and there are potentially photosensitive opsin proteins like melanopsin and panopsin in the human brain too. In order to investigate a short term response, functional connectivity changes of the brain were studied in the resting state with functional magnetic resonance imaging during bright light stimulus via the ear canal. Lateral visual and sensorimotor networks showed increased functional connectivity in the light stimulus group compared to sham controls. The lateral visual network demonstrated slowly increasing functional connectivity on average and the same temporal characteristic was shared by diverse cerebellar brain regions. Hypothetical phototransduction signal pathways leading to responses in brain function are discussed as well as some observed effects and their possible link to the findings. Findings from this study together with the plausible photoreceptor candidates suggest that the brain possesses photosensitive properties, which will have interesting implications for the modulation of brain function and understanding the basic physiology of the brain.

关键词： fMRI Resting State Functional Connectivity Light Opsin

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