Search results for "FREQUENCY"
showing 10 items of 2158 documents
A multi-centre study of candidate genes for wheeze and allergy: the International Study of Asthma and Allergies in Childhood Phase 2
2009
BACKGROUND: Common polymorphisms have been identified in genes suspected to play a role in asthma. We investigated their associations with wheeze and allergy in a case-control sample from Phase 2 of the International Study of Asthma and Allergies in Childhood. METHODS: We compared 1105 wheezing and 3137 non-wheezing children aged 8-12 years from 17 study centres in 13 countries. Genotyping of 55 candidate single nucleotide polymorphisms (SNPs) in 14 genes was performed using the Sequenom System. Logistic regression models were fitted separately for each centre and each SNP. A combined per allele odds ratio and measures of heterogeneity between centres were derived by random effects meta-ana…
Strategies and Techniques for Powering Wireless Sensor Nodes through Energy Harvesting and Wireless Power Transfer
2019
The continuous development of internet of things (IoT) infrastructure and applications is paving the way for advanced and innovative ideas and solutions, some of which are pushing the limits of state-of-the-art technology. The increasing demand for Wireless Sensor Nodes (WSNs) able to collect and transmit data through wireless communication channels, while often positioned in locations that are difficult to access, is driving research into innovative solutions involving energy harvesting (EH) and wireless power transfer (WPT) to eventually allow battery-free sensor nodes. Due to the pervasiveness of radio frequency (RF) energy, RF EH and WPT are key technologies with the potential to power …
Integration of distributed energy systems in micro-grid architecture for making a virtual power plant
2015
This paper presents a novel concept for increasing the penetration level of distributed renewable energy systems into the main electricity grid. When increasing the renewable energy penetration, it is important to implement the frequency based power delivery in distributed generators and work as traditional synchronous generators. This can be achieved by improving the power processing unit of each renewable generation units to work as active generators. But in existing grid architecture, the grid frequency is controlled as one common variable over the electricity grid. With such a method, it is difficult to use frequency based power sharing in small distributed generators and participate in…
Quantifying preferential trading in the e-MID interbank market
2015
Interbank markets allow credit institutions to exchange capital for purposes of liquidity management. These markets are among the most liquid markets in the financial system. However, liquidity of interbank markets dropped during the 2007-2008 financial crisis, and such a lack of liquidity influenced the entire economic system. In this paper, we analyze transaction data from the e-MID market which is the only electronic interbank market in the Euro Area and US, over a period of eleven years (1999-2009). We adapt a method developed to detect statistically validated links in a network, in order to reveal preferential trading in a directed network. Preferential trading between banks is detecte…
The Fit for Delivery study: rationale for the recommendations and test-retest reliability of a dietary score measuring adherence to 10 specific recom…
2012
Aiming at preventing excessive weight gain during pregnancy, 10 specific dietary recommendations are given to pregnant women in the intervention arm of the Norwegian Fit for Delivery (FFD) study. This paper presents the rationale and test-retest reliability of the food frequency questionnaire (FFQ) and a dietary score measuring adherence to the recommendations. The study is part of the ongoing FFD study, a randomised, controlled, intervention study in nulliparous pregnant women. A 43-item FFQ was developed for the FFD study. A dietary score was constructed from 10 subscales corresponding to the 10 dietary recommendations. Adding the subscales yielded a score from 0 to 10 with increasing sco…
Frequency dynamics of power systems with temporally distributed disturbances
2021
Abstract The frequency dynamics and stability of power systems is essentially affected by nature and characteristics of the disturbances occurring in the system. Conventionally, frequency transients are examined assuming a single disturbance applied at a given time. However, actual incidents in the power systems can be generally composed of a temporal sequence of events, and thus characterized by multiple power imbalances of different magnitudes and time offsets. The consideration of the effects of the temporal distribution of power imbalances is important for two main reasons: the impact on the frequency dynamics of the system in terms of frequency metrics such as minimum instantaneous fre…
HUMAN LEUKOCYTE ANTIGEN POLYMORPHISMS IN ITALIAN PRIMARY BILIARY CIRRHOSIS: A MULTICENTER STUDY OF 664 PATIENTS AND 1992 HEALTHY CONTROLS
2008
Genetic factors are critical in determining susceptibility to primary biliary cirrhosis (PBC), but there has not been a clear association with human leukocyte antigen (HLA) genes. We performed a multicenter case-control study and analyzed HLA class II DRB1 associations using a large cohort of 664 well-defined cases of PBC and 1992 controls of Italian ancestry. Importantly, healthy controls were rigorously matched not only by age and sex, but also for the geographical origin of the proband four grandparents (Northern, Central, and Southern Italy). After correction for multiple testing, DRB1*08 [odds ratio (OR), 3.3; 95% confidence interval (CI), 2.4-4.5] and DRB1*02 (OR 0.9; 95% CI 0.8-1.2) …
Genetic heterogeneity in ADHD: DAT1 gene only affects probands without CD
2008
Contains fulltext : 70183.pdf (Publisher’s version ) (Closed access) Previous studies have found heterogeneous association between DAT1-3'-UTR-VNTR and attention deficit hyperactivity disorder (ADHD). Various proportions of conduct disorder (CD) comorbidity in their ADHD samples may partially explain the observational discrepancies. Evidence for this comes from family and twin studies which found ADHD probands with CD (ADHD + CD) are genetically different from those without CD (ADHD - CD). Genotypes of 20 DAT1 markers were analyzed in 576 trios, consisting of 141 ADHD + CD and 435 ADHD - CD. In addition to the classical TDT test, a specific genetic heterogeneity test was performed to identi…
Neuroprotective Effects of Low Intensity and Low Frequency Electromagnetic �in vitro� Stimulation on Glial Cells
2020
Degenerative neurological diseases (senile dementia, Alzheimer`s disease, glaucoma), post-stroke sequelae are increasing as prevalence nowadays, in context of aging in general population, and there are strong evidences that astrocytes may play a significant role in neuroprotection. The study evaluates the effects of low intensity low frequency electromagnetic field (EMF) �in vitro� stimulation (195 mA, 7-8 Hz) on the glial cells, in different conditions, in order to identify the neuroprotective potential. Three cell lines were used for the study: the Clonetics (Lonza) line of normal human astrocytes, U87 glioblastoma tumor cells (ATCC) and L929 murine fibroblasts. The cell cultures were ex…
Design of Low-Cost Noise Measurement Sensor Network: Sensor Function Design
2010
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 applicatio…