The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Conversion Discriminative Analysis on Mild Cognitive Impairment Using Multiple Cortical Features from MR Images

Neuroimaging measurements derived from magnetic resonance imaging provide important information required for detecting changes related to the progression of mild cognitive impairment (MCI). Cortical features and changes play a crucial role in revealing unique anatomical patterns of brain regions, and further differentiate MCI patients from normal states. Four cortical features, namely, gray matter volume, cortical thickness, surface area, and mean curvature, were explored for discriminative analysis among three groups including the stable MCI (sMCI), the converted MCI (cMCI), and the normal control (NC) groups. In this study, 158 subjects (72 NC, 46 sMCI, and 40 cMCI) were selected from the Alzheimer's Disease Neuroimaging Initiative. A sparse-constrained regression model based on the l2-1-norm was introduced to reduce the feature dimensionality and retrieve essential features for the discrimination of the three groups by using a support vector machine (SVM). An optimized strategy of feature addition based on the weight of each feature was adopted for the SVM classifier in order to achieve the best classification performance. The baseline cortical features combined with the longitudinal measurements for 2 years of follow-up data yielded prominent classification results. In particular, the cortical thickness produced a classification with 98.84% accuracy, 97.5% sensitivity, and 100% specificity for the sMCI–cMCI comparison; 92.37% accuracy, 84.78% sensitivity, and 97.22% specificity for the cMCI–NC comparison; and 93.75% accuracy, 92.5% sensitivity, and 94.44% specificity for the sMCI–NC comparison. The best performances obtained by the SVM classifier using the essential features were 5–40% more than those using all of the retained features. The feasibility of the cortical features for the recognition of anatomical patterns was certified; thus, the proposed method has the potential to improve the clinical diagnosis of sub-types of MCI and predict the risk of its conversion to Alzheimer's disease

Quantitative 18F-AV1451 Brain Tau PET Imaging in Cognitively Normal Older Adults, Mild Cognitive Impairment, and Alzheimer's Disease Patients

Recent developments of tau Positron Emission Tomography (PET) allows assessment of regional neurofibrillary tangles (NFTs) deposition in human brain. Among the tau PET molecular probes, 18F-AV1451 is characterized by high selectivity for pathologic tau aggregates over amyloid plaques, limited non-specific binding in white and gray matter, and confined off-target binding. The objectives of the study are (1) to quantitatively characterize regional brain tau deposition measured by 18F-AV1451 PET in cognitively normal older adults (CN), mild cognitive impairment (MCI), and AD participants; (2) to evaluate the correlations between cerebrospinal fluid (CSF) biomarkers or Mini-Mental State Examination (MMSE) and 18F-AV1451 PET standardized uptake value ratio (SUVR); and (3) to evaluate the partial volume effects on 18F-AV1451 brain uptake.Methods: The study included total 115 participants (CN = 49, MCI = 58, and AD = 8) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Preprocessed 18F-AV1451 PET images, structural MRIs, and demographic and clinical assessments were downloaded from the ADNI database. A reblurred Van Cittertiteration method was used for voxelwise partial volume correction (PVC) on PET images. Structural MRIs were used for PET spatial normalization and region of interest (ROI) definition in standard space. The parametric images of 18F-AV1451 SUVR relative to cerebellum were calculated. The ROI SUVR measurements from PVC and non-PVC SUVR images were compared. The correlation between ROI 18F-AV1451 SUVR and the measurements of MMSE, CSF total tau (t-tau), and phosphorylated tau (p-tau) were also assessed.Results:18F-AV1451 prominently specific binding was found in the amygdala, entorhinal cortex, parahippocampus, fusiform, posterior cingulate, temporal, parietal, and frontal brain regions. Most regional SUVRs showed significantly higher uptake of 18F-AV1451 in AD than MCI and CN participants. SUVRs of small regions like amygdala, entorhinal cortex and parahippocampus were statistically improved by PVC in all groups (p < 0.01). Although there was an increasing tendency of 18F-AV-1451 SUVRs in MCI group compared with CN group, no significant difference of 18F-AV1451 deposition was found between CN and MCI brains with or without PVC (p > 0.05). Declined MMSE score was observed with increasing 18F-AV1451 binding in amygdala, entorhinal cortex, parahippocampus, and fusiform. CSF p-tau was positively correlated with 18F-AV1451 deposition. PVC improved the results of 18F-AV-1451 tau deposition and correlation studies in small brain regions.Conclusion: The typical deposition of 18F-AV1451 tau PET imaging in AD brain was found in amygdala, entorhinal cortex, fusiform and parahippocampus, and these regions were strongly associated with cognitive impairment and CSF biomarkers. Although more deposition was observed in MCI group, the 18F-AV-1451 PET imaging could not differentiate the MCI patients from CN population. More tau deposition related to decreased MMSE score and increased level of CSF p-tau, especially in ROIs of amygdala, entorhinal cortex and parahippocampus. PVC did improve the results of tau deposition and correlation studies in small brain regions and suggest to be routinely used in 18F-AV1451 tau PET quantification

Glued versus stapled anastomosis of the colon: An experimental study to determine comparative resistance to intraluminal pressure

This study compared the resistance of glued versus stapled anastomosis of the colon to intraluminal pressures at different times during healing. Forty seven female domestic pigs, mean weight of 30.7 kg, were used. Maximum physiological luminal pressures, i.e. the pressure resisted by a catheter inserted into the intestinal lumen via a puncture without it being released and without injury to the surrounding intestinal wall, was performed in 5 control animals. The remaining 42 animals were divided into 3 groups of 14 animals each based on time from anastomosis construction. Each group was divided into 2 subgroups with stapled or glued anastomoses. Intraluminal pressure was measured on the first, third, and fifth day post-surgery. The maximum pressures resisted by anastomoses were significantly higher than the physiological pressures in all groups. At all time points, stapled anastomoses resisted higher intraluminal pressures than glued ones. However, glued anastomoses resisted pressures significantly higher than physiological pressure. As healing advanced, glued anastomoses neared the resistance to intraluminal pressures of stapled anastomoses. Healing with absorbable synthetic glue was as good as with staples. Glued anastomoses resisted pressures that were statistically significantly higher than physiological intraluminal colon pressures but lower than stapled ones

Hluchy: Solving Information Privacy by Agent Architecture

Abstract: In this paper we propose how to solve information privacy using agent architecture. We focus mainly on security protection from the system itself as well as a different security view on distributed services and protection of data passed to those services. Our proposed architecture brings other difficulties with securing data but we try to overcome them. In addition, we describe possible applications of the architecture and securing private data in those applications

Glued versus stapled anastomosis of the colon: An experimental study to determine comparative resistance to intraluminal pressure

Background: This study compared the resistance of glued versus stapled anastomosis of the colon to intraluminal pressures at different times during healing. Methods: Forty seven female domestic pigs, mean weight of 30.7 kg, were used. Maximum physiological luminal pressures, i.e. the pressure resisted by a catheter inserted into the intestinal lumen via a puncture without it being released and without injury to the surrounding intestinal wall, was performed in 5 control animals. The remaining 42 animals were divided into 3 groups of 14 animals each based on time from anastomosis construction. Each group was divided into 2 subgroups with stapled or glued anastomoses. Intraluminal pressure was measured on the first, third, and fifth day post-surgery. Results: The maximum pressures resisted by anastomoses were significantly higher than the physiological pressures in all groups. At all time points, stapled anastomoses resisted higher intraluminal pressures than glued ones. However, glued anastomoses resisted pressures significantly higher than physiological pressure. As healing advanced, glued anastomoses neared the resistance to intraluminal pressures of stapled anastomoses. Conclusion: Healing with absorbable synthetic glue was as good as with staples. Glued anastomoses resisted pressures that were statistically significantly higher than physiological intraluminal colon pressures but lower than stapled ones

Assessment process of concept for mining and its impact on the region

Raw materials policy of the Slovak republic is currently in stage of the stagnation due to complex conception and outdated data (not updated from 2003). Nowadays there is an effort of the state to develop a completely new concept of the raw material policy using best available techniques in the given field. Paper is based on the study case of assessment of regional impacts of mining and processing the gold ore to public finance derived from real contitions of the Slovak republic region. Results achieved originates from the models for the assessment of the project of mining as well as from the model of environmental and social impact assessment. The main aim of the contribution is to increase the effectiveness in raw materials using with regard to environmental and social impact of the assessed region which could be implemented to the raw materials policy on the national level