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Your search keyword '"Jukka Ihalainen"' showing total 5 results
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5 results on '"Jukka Ihalainen"'

1. Circulating N-Acetylaspartate does not track brain NAA concentrations, cognitive function or features of small vessel disease in humans

Author

Eleni Rebelos, Giuseppe Daniele, Beatrice Campi, Alessandro Saba, Kalle Koskensalo, Jukka Ihalainen, Ekaterina Saukko, Pirjo Nuutila, Walter H. Backes, Jacobus F. A. Jansen, Pieter C. Dagnelie, Sebastian Köhler, Bastiaan E. de Galan, Thomas T. van Sloten, Coen D. A. Stehouwer, and Ele Ferrannini

Subjects
Medicine, Science
Abstract

Abstract N-acetylaspartate (NAA) is the second most abundant metabolite in the human brain; although it is assumed to be a proxy for a neuronal marker, its function is not fully elucidated. NAA is also detectable in plasma, but its relation to cerebral NAA levels, cognitive performance, or features of cerebral disease has not been investigated. To study whether circulating NAA tracks cerebral NAA levels, and whether circulating NAA correlates with cognitive function and features of cerebral small vessel disease (SVD). Two datasets were analyzed. In dataset 1, structural MRI was acquired in 533 subjects to assess four features of cerebral SVD. Cognitive function was evaluated with standardized test scores (N = 824). In dataset 2, brain 1H-MRS from the occipital region was acquired (N = 49). In all subjects, fasting circulating NAA was measured with mass spectrometry. Dataset 1: in univariate and adjusted for confounders models, we found no correlation between circulating NAA and the examined features of cerebral SVD. In univariate analysis, circulating NAA levels were associated inversely with the speed in information processing and the executive function score, however these associations were lost after accounting for confounders. In line with the negative findings of dataset 1, in dataset 2 there was no correlation between circulating and central NAA or total NAA levels. This study indicates that circulating NAA levels do not reflect central (occipital) NAA levels, cognitive function, or cerebral small vessel disease in man.

Published
2022
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3. Design of Networked Low-Cost Wireless Noise Measurement Sensor

Author

Ilkka KIVELÄ, Chao GAO, Jari LUOMALA, Jukka IHALAINEN, and Ismo HAKALA

Subjects
lcsh:Technology (General), lcsh:T1-995, Environmental monitoring, Continuous noise measurement, Sensor node design
Abstract

Environmental noise is considered as one of the big issues in environmental pollutions. Typical noise sources like traffic can have great influence on wellbeing and healthy. In this paper, we report the sensor function design and implementation of a wireless sensor network application for measuring environmental acoustic noise. The sensing system is built on Atmega128 and CC2420 platform. The protocol stack is based on CiNet stack with a global synchronization scheme and supports multi-hop communications. Strict filtering function specified by ITU-R 468 (namely A-weighting) is followed. Both the indoor and outdoor test results were compared with a standard sound level meter and showed a less than ± 2.1 dB mean differences in both short-term and long-term measurement. Power consumption has been measured that a single AA-type battery can sustain the application. Comparing to the traditional noise measurement method, the designed wireless sensor network solution is much lower in cost.

Published
2011

4. CiNetStrain - Wireless Strain Gauge Network - Calibration and Reliability Measurements

Author

Ismo Hakala, Timo Hongell, and Jukka Ihalainen

Subjects
Reliability (semiconductor), Strain (chemistry), business.industry, Computer science, ComputingMilieux_PERSONALCOMPUTING, Electronic engineering, Calibration, Wireless, Energy consumption, business, Wireless sensor network, Strain gauge, ComputingMethodologies_COMPUTERGRAPHICS
Abstract

Wireless sensor networks can be extended to include numerous different sensing devices. Strain gauges are the most common nondestructive sensing elements for measuring surface strain. This paper discusses the design, for the wireless CiNet network, of a strain gauge measurement system, which would make strain measurements more flexible while opening new targets of application in addition to those that traditional wired strain measuring systems can offer. The calibration and validation of the wireless strain measurements as well as energy consumption issues are also brought under observation.

Published
2013

5. Design of Low-Cost Noise Measurement Sensor Network: Sensor Function Design

Author

Jukka Ihalainen, Ismo Hakala, Ilkka Kivela, Chao Gao, and Jari Luomala

Subjects
Protocol stack, Frequency response, Noise, Key distribution in wireless sensor networks, Engineering, Noise measurement, business.industry, Mobile wireless sensor network, Electronic engineering, business, Wireless sensor network, Synchronization
Abstract

In this paper, we report the sensor function design and implementation of a wireless sensor network application for measuring environmental acoustic noise. The system is built on ATmega128 and CC2420 platform. The protocol stack is based on CiNet stack with a global synchronization scheme and supports multi-hop communications. Strict filtering function specified by ITU-R 468 (namely A-weighting) is followed. Both the indoor and outdoor test results were compared with standard sound level meters (CESVA SC-20c and Pulsar94) and showed a less than ±2dB error in both short-term and longterm measurement. Power consumption has been measured that a single AA-type battery can sustain the application. Comparing to the traditional noise measurement method, our wireless sensor network solution is much lower in cost, able to offer real-time data with sensed data timely coherent, and requests least attention after deployment.

Published
2010

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