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51.

Dementia is one of the leading causes of severe cognitive decline, it induces memory loss and impairs the daily life of millions of people worldwide. In this work, we consider the classification of dementia using magnetic resonance (MR) imaging and clinical data with machine learning models. We adapt univariate feature selection in the MR data pre-processing step as a filter-based feature selection. Bagged decision trees are also implemented to estimate the important features for achieving good classification accuracy. Several ensemble learning-based machine learning approaches, namely gradient boosting (GB), extreme gradient boost (XGB), voting-based, and random forest (RF) classifiers, are considered for the diagnosis of dementia. Moreover, we propose voting-based classifiers that train on an ensemble of numerous basic machine learning models, such as the extra trees classifier, RF, GB, and XGB. The implementation of a voting-based approach is one of the important contributions, and the performance of different classifiers are evaluated in terms of precision, accuracy, recall, and F1 score. Moreover, the receiver operating characteristic curve (ROC) and area under the ROC curve (AUC) are used as metrics for comparing these classifiers. Experimental results show that the voting-based classifiers often perform better compared to the RF, GB, and XGB in terms of precision, recall, and accuracy, thereby indicating the promise of differentiating dementia from imaging and clinical data.

  相似文献   
52.
The rituals of riparian communities are frequently linked to the flow regimes of their river. These dependencies need to be identified, quantified and communicated to policy makers who manage river flows. This paper describes the first attempt to explicitly evaluate the flows required to maintain the cultural and spiritual activities in the upper Ganga River basin. Riparian dwellers and visitors were interviewed and the responses analyzed to obtain an overview of the needs and motivations for cultural flows. The approach enhances the overall concept of environmental flow assessment, especially in river basins where spiritual values ascribed to rivers are high.  相似文献   
53.
The water resources of the Koshi Basin (87,311 km2) are largely untapped, and while proposals for their development exist, their impacts on current and future water demand are not quantified. The current study is the first to evaluate the impacts of 11 proposed development projects for hydropower generation and water storage. We find that 29,733 GWh of hydropower could be generated annually and 8382 million m3 of water could be stored. This could satisfy unmet demand in the current (660 million m3) basin situation and in future scenarios – i.e. population, agricultural and industrial growth – that are projected to have 920, 970 and 1003 million m3 of unmet demand, respectively, by 2050.  相似文献   
54.
Chalcopyrite copper indium aluminum diselenide (CuIn0.81Al0.19Se2) compound is prepared by direct reaction of high purity elemental copper, indium, aluminum and selenium in their stoichiometric proportion. Structural and compositional characterizations of pulverized material confirm the formation of a single phase, polycrystalline nature. CuInAlSe2 (CIAS) thin films are deposited on organically cleaned soda lime glass substrates using flash evaporation technique by varying the substrate temperatures in the range from 423 K to 573 K. Influence of substrate temperature observed by X-ray diffraction (XRD), scanning electron microscope (SEM), optical and electrical measurement. CIAS Films grown at different substrate temperatures are polycrystalline in nature, exhibiting a chalcopyrite structure with lattice parameters a = ∼0.576 nm and c = ∼1.151 nm. The crystallinity in the films increases with increasing substrate temperature up to 473 K, and tend to degrade at higher substrate temperatures. Optical band gap is in the range of 1.20 eV–1.38 eV and the absorption coefficient is close to 105 cm−1. Electrical characterization reveals p-type conductivity and the structural, morphological and optical properties indicate potential use of CIAS thin films as an absorber layer for thin film solar cell applications.  相似文献   
55.
The preform of human mitochondrial uracil-DNA glycosylase (UNG1) contains 35 N-terminal residues required for mitochondrial targeting. We have examined processing of human UNG1 expressed in insect cells and processing in vitro by human mitochondrial extracts . In insect cells we detected a major processed form lacking 29 of the 35 unique N-terminal residues (UNG1Delta29, 31 kDa) and two minor forms lacking the 75 and 77 N-terminal residues, respectively (UNG1Delta75 and UNG1Delta77, 26 kDa). Purified UNG1Delta29 was effectively cleaved in vitro to a fully active 26 kDa form by human mitochondrial extracts. Furthermore, endogenous forms of 31 and 26 kDa were also observed in HeLa mitochondrial extracts. The sequences at the cleavage sites, as identified by peptide sequencing, were compatible with the known specificity of mitochondrial processing peptidase (MPP). However, in vitro cleavage of UNG1Delta29 by mitochondrial extracts did not require divalent cations and was stimulated by EDTA, indicating the involvement of a processing peptidase distinct from MPP at the second site. Interestingly, while UNG1Delta29 generally has the typical properties reported for other uracil-DNA glycosylases, it is not inhibited by apurinic/apyrimidinic sites. Our results indicate that the preform of human mitochondrial uracil-DNA glycosylase is processed to distinctly different forms lacking 29 or 75/77 N-terminal residues, respectively.  相似文献   
56.
A series of novel zinc oxide (ZnO) containing bioactive glass compositions in SiO2-Na2O-CaO-P2O5 system and composite with hydroxyapatite (HAp) nano-particles were developed and applied as coating on Ti-6Al-4V substrates. The bioactive glasses and their composites were also processed to yield dense scaffolds, porous scaffolds and porous bone filler materials. The coating materials and the coatings were characterized and evaluated by different in vitro techniques to establish their superior mechanical properties. The cytotoxicity test of the coating material, porous and dense scaffolds and coated specimens showed non-cytotoxicity, biocompatibility and promising in vitro bioactivity for all tested samples. The dissolution behaviour studies of the bioactive glasses and the composites in simulated body fluid showed promising in vitro release pattern and bioactivity for all tested samples. Addition of nanosized HAp improves mechanical properties of the bioactive glass coating without affecting the in vitro bioactivity.  相似文献   
57.
In this paper we obtain a fundamental result to find the exact wirelength of 1-fault hamiltonian graphs into wheels and fans. Using this result we compute the exact wirelength of circulant graphs, generalized Petersen graphs, augmented cubes, crossed cubes, M?bius cubes, locally twisted cubes, twisted cubes, twisted n-cubes, generalized twisted cubes, hierarchical cubic networks, alternating group graphs, arrangement graphs and tori into wheels and fans. In addition, we find the exact wirelength of hypercubes, folded hypercubes, shuffle cubes, cube connected cycles, cyclic-cubes, wrapped butterfly networks and star graphs into fans.  相似文献   
58.
Methane Emission from Rice Fields at Cuttack, India   总被引:1,自引:0,他引:1  
Methane (CH4) emission from rice fields at Cuttack (State of Orissa, eastern India) has been recorded using an automatic measurement system (closed chamber method) from 1995–1998. Experiments were laid out to test the impact of water regime, organic amendment, inorganic amendment and rice cultivars. Organic amendments in conjunction with chemical N (urea) effected higher CH4 flux over that of chemical N alone. Application of Sesbania, Azolla and compost resulted in 132, 65 and 68 kg CH4 ha–1 in the wet season of 1996 when pure urea application resulted in 42 kg CH4 ha–1. Intermittent irrigation reduced emissions by 15% as compared to continuous flooding in the dry season of 1996. In the wet season of 1995, four cultivars were tested under rainfed conditions resulting in a range of emissions from 20 to 44 kg CH4 ha–1. Application of nitrification inhibitor dicyandiamide (DCD) inhibited while Nimin stimulated CH4 flux from flooded rice compared to that of urea N alone. Wide variation in CH4 production and oxidation potentials was observed in rice soils tested. Methane oxidation decreased with soil depth, fertilizer-N and nitrification inhibitors while organic amendment stimulated it. The results indicate that CH4 emission from the representative rainfed ecosystem at the experimental site averaged to 32 kg CH4 ha–1 yr–1.  相似文献   
59.
60.
To investigate the hypothesis that embryologic abnormalities in the venous valves may be associated with abnormal cardiac development, we examined the right atrial morphologic characteristics in 20 hearts with underdevelopment of the right heart and 17 normal hearts. In the study group, 16 (80%) of the patients had significantly enlarged eustachian valves, one (5%) was slightly enlarged, and three (15%) were smaller than expected. Five (25%) had cor triatriatum dexter. In comparison, eustachian valves in the control specimens were prominent in only one (6%), normal in five (29%), and almost absent in eight (47%). The thebesian valve was also more prominent in the study cohort when compared with controls (p < 0.05). No other morphologic features of the right atrium analyzed in this study differed from those found in normal specimens. We speculate that failure of the venous valves to regress appropriately may create abnormalities in fetal circulation that predispose the fetus to maldevelopment of the right heart structures.  相似文献   
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