This study investigates plug-in hybrid electric vehicles (PHEVs) as providers of regulating power in the form of primary, secondary and tertiary frequency control. Previous studies have shown that ...PHEVs could generate substantial profits while providing ancillary services. This study investigates under what conditions PHEVs can generate revenues using actual market data, i.e. prices and activations of regulating power, from Sweden and Germany from four months in 2008. PHEV market participation is modelled for individual vehicles in a fleet subject to a simulated movement pattern. Costs for infrastructure and vehicle-to-grid equipment are not included in the analysis. The simulation results indicate that maximum average profits generated on the German markets are in the range 30–80
€ per vehicle and month whereas the Swedish regulating power markets give no profit.
In addition, an analysis is performed to identify strengths, weaknesses, opportunities, and threats (SWOT) of PHEVs as regulating power providers. Based on the simulation results and the SWOT analysis, characteristics for an ideal regulating power market for PHEVs are presented.
In this paper we describe a method for retrospective estimation and correction of eddy current (EC)-induced distortions and subject movement in diffusion imaging. In addition a susceptibility-induced ...field can be supplied and will be incorporated into the calculations in a way that accurately reflects that the two fields (susceptibility- and EC-induced) behave differently in the presence of subject movement. The method is based on registering the individual volumes to a model free prediction of what each volume should look like, thereby enabling its use on high b-value data where the contrast is vastly different in different volumes. In addition we show that the linear EC-model commonly used is insufficient for the data used in the present paper (high spatial and angular resolution data acquired with Stejskal–Tanner gradients on a 3T Siemens Verio, a 3T Siemens Connectome Skyra or a 7T Siemens Magnetome scanner) and that a higher order model performs significantly better.
The method is already in extensive practical use and is used by four major projects (the WU-UMinn HCP, the MGH HCP, the UK Biobank and the Whitehall studies) to correct for distortions and subject movement.
•We present a new method for correction of eddy current-induced distortions and subject movement in diffusion data.•It is based on alignment to predictions based on a Gaussian process•The results indicate that one can achieve reliable corrections even for high b-value data (b=7000).•A comparison to correlation ratio based registration (eddy_correct) indicates that the new method is vastly superior.
Despite its great potential in studying brain anatomy and structure, diffusion magnetic resonance imaging (dMRI) is marred by artefacts more than any other commonly used MRI technique. In this paper ...we present a non-parametric framework for detecting and correcting dMRI outliers (signal loss) caused by subject motion.
Signal loss (dropout) affecting a whole slice, or a large connected region of a slice, is frequently observed in diffusion weighted images, leading to a set of unusable measurements. This is caused by bulk (subject or physiological) motion during the diffusion encoding part of the imaging sequence. We suggest a method to detect slices affected by signal loss and replace them by a non-parametric prediction, in order to minimise their impact on subsequent analysis. The outlier detection and replacement, as well as correction of other dMRI distortions (susceptibility-induced distortions, eddy currents (EC) and subject motion) are performed within a single framework, allowing the use of an integrated approach for distortion correction. Highly realistic simulations have been used to evaluate the method with respect to its ability to detect outliers (types 1 and 2 errors), the impact of outliers on retrospective correction of movement and distortion and the impact on estimation of commonly used diffusion tensor metrics, such as fractional anisotropy (FA) and mean diffusivity (MD). Data from a large imaging project studying older adults (the Whitehall Imaging sub-study) was used to demonstrate the utility of the method when applied to datasets with severe subject movement.
The results indicate high sensitivity and specificity for detecting outliers and that their deleterious effects on FA and MD can be almost completely corrected.
•We present a framework for correction of distortions, subject movement and signal dropout in diffusion weighted images.•It has been validated on realistic simulated data.•One can reliably correct for signal dropout as long as the affected slices constitute no more than 10% of the total.
Dealing with confounds is an essential step in large cohort studies to address problems such as unexplained variance and spurious correlations. UK Biobank is a powerful resource for studying ...associations between imaging and non-imaging measures such as lifestyle factors and health outcomes, in part because of the large subject numbers. However, the resulting high statistical power also raises the sensitivity to confound effects, which therefore have to be carefully considered. In this work we describe a set of possible confounds (including non-linear effects and interactions that researchers may wish to consider for their studies using such data). We include descriptions of how we can estimate the confounds, and study the extent to which each of these confounds affects the data, and the spurious correlations that may arise if they are not controlled. Finally, we discuss several issues that future studies should consider when dealing with confounds.
UK Biobank is a large-scale prospective epidemiological study with all data accessible to researchers worldwide. It is currently in the process of bringing back 100,000 of the original participants ...for brain, heart and body MRI, carotid ultrasound and low-dose bone/fat x-ray. The brain imaging component covers 6 modalities (T1, T2 FLAIR, susceptibility weighted MRI, Resting fMRI, Task fMRI and Diffusion MRI). Raw and processed data from the first 10,000 imaged subjects has recently been released for general research access. To help convert this data into useful summary information we have developed an automated processing and QC (Quality Control) pipeline that is available for use by other researchers. In this paper we describe the pipeline in detail, following a brief overview of UK Biobank brain imaging and the acquisition protocol. We also describe several quantitative investigations carried out as part of the development of both the imaging protocol and the processing pipeline.
It has been suggested that variation in brain structure correlates with the sizes of individuals' social networks. Whether variation in social network size causes variation in brain structure, ...however, is unknown. To address this question, we neuroimaged 23 monkeys that had been living in social groups set to different sizes. Subject comparison revealed that living in larger groups caused increases in gray matter in mid-superior temporal sulcus and rostral prefrontal cortex and increased coupling of activity in frontal and temporal cortex. Social network size, therefore, contributes to changes both in brain structure and function. The changes have potential implications for an animal's success in a social context; gray matter differences in similar areas were also correlated with each animal's dominance within its social network.
Long-term exposure to particulate matter (PM) in ambient air has been associated with cardiovascular mortality, but few studies have considered incident disease in relation to PM from different ...sources.
We aimed to study associations between long-term exposure to different types of PM and sources, and incident ischemic heart disease (IHD) and stroke in three Swedish cities.
Based on detailed emission databases, monitoring data, and high-resolution dispersion models, we calculated source contributions to PM with aerodynamic diameter
(
), PM with aerodynamic diameter
(
), and black carbon (BC) from road wear, traffic exhaust, residential heating, and other sources in Gothenburg, Stockholm, and Umeå. Registry data for participants from four cohorts were used to obtain incidence of IHD and stroke for first hospitalization or death. We constructed time windows of exposure for same-year, 1- to 5-y, and 6- to 10-y averages preceding incidence from annual averages at residential addresses. Risk estimates were based on random effects meta-analyses of cohort-specific Cox proportional hazard models.
We observed 5,166 and 3,119 incident IHD and stroke cases, respectively, in 114,758 participants. Overall, few consistent associations were observed between the different air pollution measures and IHD or stroke incidence. However, same-year levels of ambient locally emitted BC (range:
) were associated with a 4.0% higher risk of incident stroke per interquartile range (IQR),
95% confidence interval (CI): 0.04, 7.8. This association was primarily related to BC from traffic exhaust.
(range:
) and
(range:
) were not associated with stroke. Associations with incident IHD were observed only for
exposure from residential heating.
Few consistent associations were observed between different particulate components and IHD or stroke. However, long-term residential exposure to locally emitted BC from traffic exhaust was associated with stroke incidence. The comparatively low exposure levels may have contributed to the paucity of associations. https://doi.org/10.1289/EHP4757.
To estimate the incidence of pregnancy-associated breast cancer during different calendar periods and when pregnancy-associated breast cancer was diagnosed in relation to delivery.
This was a ...population-based cohort study using data from Swedish registers between 1963 and 2002, encompassing women aged 15-44 years at the date of breast cancer diagnosis. Outcome measures included incidence of pregnancy-associated breast cancer per 100,000 deliveries, the proportion of pregnancy-associated breast cancer among all breast cancers, and observed-to-expected rates.
Between 1963 and 2002, 1,161 cases of pregnancy-associated breast cancer among a total of 16,620 breast cancers were identified in women aged 15 to 44 years. The incidence of pregnancy-associated breast cancer increased from 16.0 to 37.4 per 100,000 deliveries comparing the first and last calendar periods under study. During pregnancy, the overall incidence was 2.4 per 100,000 deliveries; the incidence during the first and second year after delivery was 10.6 and 15.0 per 100,000 deliveries, respectively. Fewer pregnancy-associated breast cancers than expected were diagnosed during pregnancy and the first 6 months after delivery. Thereafter, there was no difference between observed compared with expected number of breast cancers.
The incidence of pregnancy-associated breast cancer increased during the study period, partly caused by a trend of postponement of childbearing to an older age. The present findings suggest that breast cancer is underdiagnosed during pregnancy and lactation.
III.
For centuries, domestic horses have represented an important means of transport and served as working and companion animals. Although their role in transportation is less important today, many horse ...breeds are still subject to intense selection based on their pattern of locomotion. A striking example of such a selected trait is the ability of a horse to perform additional gaits other than the common walk, trot and gallop. Those could be four‐beat ambling gaits, which are particularly smooth and comfortable for the rider, or pace, used mainly in racing. Gaited horse breeds occur around the globe, suggesting that gaitedness is an old trait, selected for in many breeds. A recent study discovered that a nonsense mutation in DMRT3 has a major impact on gaitedness in horses and is present at a high frequency in gaited breeds and in horses bred for harness racing. Here, we report a study of the worldwide distribution of this mutation. We genotyped 4396 horses representing 141 horse breeds for the DMRT3 stop mutation. More than half (2749) of these horses also were genotyped for a SNP situated 32 kb upstream of the DMRT3 nonsense mutation because these two SNPs are in very strong linkage disequilibrium. We show that the DMRT3 mutation is present in 68 of the 141 genotyped horse breeds at a frequency ranging from 1% to 100%. We also show that the mutation is not limited to a geographical area, but is found worldwide. The breeds with a high frequency of the stop mutation (>50%) are either classified as gaited or bred for harness racing.
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