Brain radiomics can reflect the characteristics of brain pathophysiology. However, the value of T1-weighted images, quantitative susceptibility mapping, and R2* mapping in the diagnosis of ...Parkinson's disease (PD) was underestimated in previous studies. In this prospective study to establish a model for PD diagnosis based on brain imaging information, we collected high-resolution T1-weighted images, R2* mapping, and quantitative susceptibility imaging data from 171 patients with PD and 179 healthy controls recruited from August 2014 to August 2019. According to the inclusion time, 123 PD patients and 121 healthy controls were assigned to train the diagnostic model, while the remaining 106 subjects were assigned to the external validation dataset. We extracted 1408 radiomics features, and then used data-driven feature selection to identify informative features that were significant for discriminating patients with PD from normal controls on the training dataset. The informative features so identified were then used to construct a diagnostic model for PD. The constructed model contained 36 informative radiomics features, mainly representing abnormal subcortical iron distribution (especially in the substantia nigra), structural disorganization (e.g., in the inferior temporal, paracentral, precuneus, insula, and precentral gyri), and texture misalignment in the subcortical nuclei (e.g., caudate, globus pallidus, and thalamus). The predictive accuracy of the established model was 81.1 ± 8.0% in the training dataset. On the external validation dataset, the established model showed predictive accuracy of 78.5 ± 2.1%. In the tests of identifying early and drug-naïve PD patients from healthy controls, the accuracies of the model constructed on the same 36 informative features were 80.3 ± 7.1% and 79.1 ± 6.5%, respectively, while the accuracies were 80.4 ± 6.3% and 82.9 ± 5.8% for diagnosing middle-to-late PD and those receiving drug management, respectively. The accuracies for predicting tremor-dominant and non-tremor-dominant PD were 79.8 ± 6.9% and 79.1 ± 6.5%, respectively. In conclusion, the multiple-tissue-specific brain radiomics model constructed from magnetic resonance imaging has the ability to discriminate PD and exhibits the advantages for improving PD diagnosis.
Flexible-resource theories characterize working memory as a flexible resource that can store either a large number of lowquality representations or a small number of high-quality representations. In ...contrast, limited-item theories propose that the number of items that can be stored in working memory is strictly limited and cannot be increased by decreasing the quality of the representations. We tested these fundamentally different conceptualizations of working memory capacity by determining whether observers could trade quality for quantity in working memory when given incentives to do so. We found no evidence that observers could increase the number of representations by decreasing their quality in working memory, but observers could make such a trade-off at earlier processing stages. Our results show that the capacity limit of working memory is best characterized as a limit on the number of items that can be stored and not as a limit on a finely divisible resource that simultaneously determines the number and quality of the representations.
► We review most popular data-driven PM–FD methods with recent developments. ► Systematic comparison and analysis among these methods are given. ► All the methods are tested on TE process. ► Based on ...the simulations, some important concluding remarks are presented. ► The results provide a reference on performance of PM–FD for large scale processes.
This paper provides a comparison study on the basic data-driven methods for process monitoring and fault diagnosis (PM–FD). Based on the review of these methods and their recent developments, the original ideas, implementation conditions, off-line design and on-line computation algorithms as well as computation complexity are discussed in detail. In order to further compare their performance from the application viewpoint, an industrial benchmark of Tennessee Eastman (TE) process is utilized to illustrate the efficiencies of all the discussed methods. The study results are dedicated to provide a reference for achieving successful PM–FD on large scale industrial processes. Some important remarks are finally concluded in this paper.
It is widely believed that attention selects locations at an earlier stage than it selects nonspatial features, but this has been tested only under conditions of minimal competition. We found that, ...when competition was increased, color-based attention was able to influence the feedforward flow of information in humans within 100 ms of stimulus onset, even for stimuli presented at unattended locations. Thus, color-based attention can operate as early as, and independently from, spatial attention.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Metabotropic glutamate receptor 2 (mGlu2) is a known target for treating several central nervous system (CNS) disorders. To develop a viable positron emission tomography (PET) ligand for mGlu2, we ...identified new candidates 5a–i that are potent negative allosteric modulators (NAMs) of mGlu2. Among these candidates, 4-(2-fluoro-4-methoxyphenyl)-5-((1-methyl-1H-pyrazol-3-yl)methoxy)picolinamide (5i, also named as 11CMG2-1812) exhibited high potency, high subtype selectivity, and favorable lipophilicity. Compound 5i was labeled with positron-emitting carbon-11 (11C) to obtain 11C5i in high radiochemical yield and high molar activity by O-11Cmethylation of the phenol precursor 12 with 11CCH3I. In vitro autoradiography with 11C5i showed heterogeneous radioactive accumulation in the brain tissue sections, ranked in the order: cortex > striatum > hippocampus > cerebellum ≫ thalamus > pons. PET study of 11C5i indicated in vivo specific binding of mGlu2 in the rat brain. Based on the 11C5i scaffold, further optimization for new candidates is underway to identify a more suitable ligand for imaging mGlu2.
Evapotranspiration is a major component of the global water cycle and provides a critical nexus between terrestrial water, carbon and surface energy exchanges. Evapotranspiration is inherently ...difficult to measure and predict especially at large spatial scales. Remote sensing provides a cost‐effective method to estimate evapotranspiration at regional to global scales. In the past three decades a large number of studies on remote sensing based evapotranspiration estimation have emerged. This review summarizes the basic theories underpinning current remote sensing based evapotranspiration estimation methods. It also lays out the development history of these methods and compares their advantages and limitations. Several key directions for further study are identified and discussed, including identification of uncertainty sources in remote sensing evapotranspiration models, merging of different remote sensing methods, application of data assimilation and fusion techniques in producing robust evapotranspiration estimates, and utilization of multi‐source remote sensing data and latest sensor technologies. Further advances in the remote sensing of evapotranspiration will enhance capabilities for monitoring of the global water and energy cycles, including water availability and ecosystem responses and feedbacks to climate change and human impacts. WIREs Water 2016, 3:834–853. doi: 10.1002/wat2.1168
This article is categorized under:
Science of Water > Hydrological Processes
Science of Water > Methods
An improved understanding of etiological mechanisms in Parkinson's disease (PD) is urgently needed because the number of affected individuals is projected to increase rapidly as populations age. We ...present results from a blood-based methylome-wide association study of PD involving meta-analysis of 229 K CpG probes in 1,132 cases and 999 controls from two independent cohorts. We identify two previously unreported epigenome-wide significant associations with PD, including cg06690548 on chromosome 4. We demonstrate that cg06690548 hypermethylation in PD is associated with down-regulation of the SLC7A11 gene and show this is consistent with an environmental exposure, as opposed to medications or genetic factors with effects on DNA methylation or gene expression. These findings are notable because SLC7A11 codes for a cysteine-glutamate anti-porter regulating levels of the antioxidant glutathione, and it is a known target of the environmental neurotoxin β-methylamino-L-alanine (BMAA). Our study identifies the SLC7A11 gene as a plausible biological target in PD.
Urban vegetations are widely used as one of the mitigation approaches to combat the public health threat from air particulate matter (PM) pollution for urban residents. However, vegetation effect at ...the points of interest (e.g. leeward wall, windward wall, pedestrian-level) in street-canyon from different vegetation configurations on the air quality is still not well established. We, therefore, used the numerical simulation approach to evaluate vegetation effect (VE) for different vegetation configurations (VCs) (e.g. tree or tree-shrub plantings in two sides and either side of windward or leeward) with several tree species on the traffic-originated PM pollutants in a street-canyon under a perpendicular wind. The total VE varied from −4.0% to 20.6% while pedestrian-level VE from −3.5% to 15.4% depending on different VCs. Cypress species have better total VE varying from 3.5% to 11.5% and pedestrian-level VE from 4.8% to 10.9% than the other species for same VC due to its higher deposition velocity. For those only trees used cases, the best VEs (pedestrian-level VE: 3.3%–10.9%; total VE: 2.1%–11.5%) were found on the leeward side planting where is closer to the higher polluted domain and had less obstructions for wind movement. We found that two sides planting of enhanced tree-shrub configuration by Cypress in the street-canyon was an optimal strategy to improve the total VE by 19.3%–20.6% and pedestrian-level VE 14.1%–15.4%, as well as mitigate the highly concentrated PM in the street center. The VE for the leeward wall was significantly correlated with aerodynamic parameter (CdLAD) (P < 0.001) while VEs for the windward wall and pedestrian level with deposition parameter (LADvd) (P < 0.001). Clearly, street-canyon air quality can be improved by making good use of pressure loss coefficient of vegetation to alter pollutants distribution and selecting vegetation with high deposition velocity to filter more pollutants. Our research provides insights for urban planners and designers to develop the best management practices of urban forestry.
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•Vegetation effect (VE) on traffic PM depends on its configuration.•Vegetation planting design is more critical than the volume for PM reduction.•Positive vegetation effect on PM reduction for the perpendicular wind was found.•Leeward VE significantly correlated with aerodynamic parameter.•Windward and pedestrian VE significantly correlated with deposition parameter.
Summary Background Stroke is a leading cause of death and disability, especially in low-income and middle-income countries. We sought to quantify the importance of potentially modifiable risk factors ...for stroke in different regions of the world, and in key populations and primary pathological subtypes of stroke. Methods We completed a standardised international case-control study in 32 countries in Asia, America, Europe, Australia, the Middle East, and Africa. Cases were patients with acute first stroke (within 5 days of symptom onset and 72 h of hospital admission). Controls were hospital-based or community-based individuals with no history of stroke, and were matched with cases, recruited in a 1:1 ratio, for age and sex. All participants completed a clinical assessment and were requested to provide blood and urine samples. Odds ratios (OR) and their population attributable risks (PARs) were calculated, with 99% confidence intervals. Findings Between Jan 11, 2007, and Aug 8, 2015, 26 919 participants were recruited from 32 countries (13 447 cases 10 388 with ischaemic stroke and 3059 intracerebral haemorrhage and 13 472 controls). Previous history of hypertension or blood pressure of 140/90 mm Hg or higher (OR 2·98, 99% CI 2·72–3·28; PAR 47·9%, 99% CI 45·1–50·6), regular physical activity (0·60, 0·52–0·70; 35·8%, 27·7–44·7), apolipoprotein (Apo)B/ApoA1 ratio (1·84, 1·65–2·06 for highest vs lowest tertile; 26·8%, 22·2–31·9 for top two tertiles vs lowest tertile), diet (0·60, 0·53–0·67 for highest vs lowest tertile of modified Alternative Healthy Eating Index mAHEI; 23·2%, 18·2–28·9 for lowest two tertiles vs highest tertile of mAHEI), waist-to-hip ratio (1·44, 1·27–1·64 for highest vs lowest tertile; 18·6%, 13·3–25·3 for top two tertiles vs lowest), psychosocial factors (2·20, 1·78–2·72; 17·4%, 13·1–22·6), current smoking (1·67, 1·49–1·87; 12·4%, 10·2–14·9), cardiac causes (3·17, 2·68–3·75; 9·1%, 8·0–10·2), alcohol consumption (2·09, 1·64–2·67 for high or heavy episodic intake vs never or former drinker; 5·8%, 3·4–9·7 for current alcohol drinker vs never or former drinker), and diabetes mellitus (1·16, 1·05–1·30; 3·9%, 1·9–7·6) were associated with all stroke. Collectively, these risk factors accounted for 90·7% of the PAR for all stroke worldwide (91·5% for ischaemic stroke, 87·1% for intracerebral haemorrhage), and were consistent across regions (ranging from 82·7% in Africa to 97·4% in southeast Asia), sex (90·6% in men and in women), and age groups (92·2% in patients aged ≤55 years, 90·0% in patients aged >55 years). We observed regional variations in the importance of individual risk factors, which were related to variations in the magnitude of ORs (rather than direction, which we observed for diet) and differences in prevalence of risk factors among regions. Hypertension was more associated with intracerebral haemorrhage than with ischaemic stroke, whereas current smoking, diabetes, apolipoproteins, and cardiac causes were more associated with ischaemic stroke (p<0·0001). Interpretation Ten potentially modifiable risk factors are collectively associated with about 90% of the PAR of stroke in each major region of the world, among ethnic groups, in men and women, and in all ages. However, we found important regional variations in the relative importance of most individual risk factors for stroke, which could contribute to worldwide variations in frequency and case-mix of stroke. Our findings support developing both global and region-specific programmes to prevent stroke. Funding Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Health Research Board Ireland, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland (Sweden), AstraZeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MSD, Chest, Heart and Stroke Scotland, and The Stroke Association, with support from The UK Stroke Research Network.
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