247 research outputs found
A multivariate finite mixture latent trajectory model with application to dementia studies
Dementia patients exhibit considerable heterogeneity in individual trajectories of cognitive decline, with some patients showing rapid decline following diagnoses while others exhibiting slower decline or remaining stable for several years. Dementia studies often collect longitudinal measures of multiple neuropsychological tests aimed to measure patients’ decline across a number of cognitive domains. We propose a multivariate finite mixture latent trajectory model to identify distinct longitudinal patterns of cognitive decline simultaneously in multiple cognitive domains, each of which is measured by multiple neuropsychological tests. EM algorithm is used for parameter estimation and posterior probabilities are used to predict latent class membership. We present results of a simulation study demonstrating adequate performance of our proposed approach and apply our model to the Uniform Data Set from the National Alzheimer's Coordinating Center to identify cognitive decline patterns among dementia patients
The Micro-Changes of Fly Ash in the Utilization of “Dip in One Acid Twice/Unite Two Kinds of Alkalis”
Determined the new technology of element leaching in fly ash’s utilization---- “dip in one acid twice/unite two kinds of alkalis” through comparison tests, the technique consist of four phases: acid leaching、alkali dissolution, calcination and second acid leaching, the maximum fine utilization rates of silicon, aluminum, iron are respectively 97.07%, 86.67%, 96.54%, the total utilization rate is 100%. Analyzed the micro-changes of fly ash in the utilization process by X-ray diffraction and scanning electron microscope, the results show that: (1)there are mineral changes exist in acid leaching process, and some amorphous active substance is dissolved, it destroy the surface structure of fly ash, conducive to the conduct of following response; (2)after alkali leaching, most of the amorphous SiO2 is dissolved, crystalline SiO2 (quartz) has not changed; (3)after calcination with sodium carbonate, all the mine phases are transformed into nepheline and a small amount of pyroxene which are layer (film) structure , except a small amount of residual quartz crystal;(4)after the second acid leaching, the fly ash is transformed into silica II which mainly constitute by the amorphous SiO2.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー
VulDeePecker: A Deep Learning-Based System for Vulnerability Detection
The automatic detection of software vulnerabilities is an important research
problem. However, existing solutions to this problem rely on human experts to
define features and often miss many vulnerabilities (i.e., incurring high false
negative rate). In this paper, we initiate the study of using deep
learning-based vulnerability detection to relieve human experts from the
tedious and subjective task of manually defining features. Since deep learning
is motivated to deal with problems that are very different from the problem of
vulnerability detection, we need some guiding principles for applying deep
learning to vulnerability detection. In particular, we need to find
representations of software programs that are suitable for deep learning. For
this purpose, we propose using code gadgets to represent programs and then
transform them into vectors, where a code gadget is a number of (not
necessarily consecutive) lines of code that are semantically related to each
other. This leads to the design and implementation of a deep learning-based
vulnerability detection system, called Vulnerability Deep Pecker
(VulDeePecker). In order to evaluate VulDeePecker, we present the first
vulnerability dataset for deep learning approaches. Experimental results show
that VulDeePecker can achieve much fewer false negatives (with reasonable false
positives) than other approaches. We further apply VulDeePecker to 3 software
products (namely Xen, Seamonkey, and Libav) and detect 4 vulnerabilities, which
are not reported in the National Vulnerability Database but were "silently"
patched by the vendors when releasing later versions of these products; in
contrast, these vulnerabilities are almost entirely missed by the other
vulnerability detection systems we experimented with
Evolutionary and regulatory pattern analysis of soybean Ca2+ ATPases for abiotic stress tolerance
P2-type Ca2+ ATPases are responsible for cellular Ca2+ transport, which plays an important role in plant development and tolerance to biotic and abiotic stresses. However, the role of P2-type Ca2+ ATPases in stress response and stomatal regulation is still elusive in soybean. In this study, a total of 12 P2-type Ca2+ ATPases genes (GmACAs and GmECAs) were identified from the genome of Glycine max. We analyzed the evolutionary relationship, conserved motif, functional domain, gene structure and location, and promoter elements of the family. Chlorophyll fluorescence imaging analysis showed that vegetable soybean leaves are damaged to different extents under salt, drought, cold, and shade stresses. Real-time quantitative PCR (RT-qPCR) analysis demonstrated that most of the GmACAs and GmECAs are up-regulated after drought, cold, and NaCl treatment, but are down-regulated after shading stress. Microscopic observation showed that different stresses caused significant stomatal closure. Spatial location and temporal expression analysis suggested that GmACA8, GmACA9, GmACA10, GmACA12, GmACA13, and GmACA11 might promote stomatal closure under drought, cold, and salt stress. GmECA1 might regulate stomatal closure in shading stress. GmACA1 and GmECA3 might have a negative function on cold stress. The results laid an important foundation for further study on the function of P2-type Ca2+ ATPase genes GmACAs and GmECAs for breeding abiotic stress-tolerant vegetable soybean
Glassy carbon electrode modified with 7,7,8,8-tetracyanoquinodimethane and graphene oxide triggered a synergistic effect: low-potential amperometric detection of reduced glutathione.
A sensitive electrochemical sensor based on the synergistic effect of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and graphene oxide (GO) for low-potential amperometric detection of reduced glutathione (GSH) in pH 7.2 phosphate buffer solution (PBS) has been reported. This is the first time that the combination of GO and TCNQ have been successfully employed to construct an electrochemical sensor for the detection of glutathione. The surface of the glassy carbon electrode (GCE) was modified by a drop casting using TCNQ and GO. Cyclic voltammetric measurements showed that TCNQ and GO triggered a synergistic effect and exhibited an unexpected electrocatalytic activity towards GSH oxidation, compared to GCE modified with only GO, TCNQ or TCNQ/electrochemically reduced GO. Three oxidation waves for GSH were found at −0.05, 0.1 and 0.5 V, respectively. Amperometric techniques were employed to detect GSH sensitively using a GCE modified with TCNQ/GO at −0.05 V. The electrochemical sensor showed a wide linear range from 0.25 to 124.3 μM and 124.3 μM to 1.67 mM with a limit of detection of 0.15 μM. The electroanalytical sensor was successfully applied towards the detection of GSH in an eye drop solution
Association of Hypercholesterolemia with Alzheimer’s Disease Pathology and Cerebral Amyloid Angiopathy
Background:
Animal studies have shown that diet-induced hypercholesterolemia (HC) increases amyloid-β (Aβ) accumulation and accelerates Alzheimer’s disease (AD) pathology. However, the association of HC with AD in human studies has not been consistently established.
Objective:
We aimed to investigate the relationship between HC and risk of AD neuropathology in a large national sample with autopsies.
Methods:
This study used neuropathological and clinical data from 3,508 subjects from the National Alzheimer’s Coordinating Center (NACC) who underwent autopsies from 2005 to 2017. Demographic and clinical characteristics, as well as neuropathological outcomes were compared between subjects with and without HC. Associations between HC and AD neuropathology were examined by multivariate ordinal logistic regressions adjusting for potential confounders.
Results:
HC was not associated with any AD neuropathology in a model only adjusting for demographic variables. However, HC was significantly associated with higher CERAD neuritic and diffuse plaque burden, higher Braak stage, and more severe cerebral amyloid angiopathy when analyzed in a multivariate model controlling for comorbidities. Additional adjusting for cerebrovascular conditions did not diminish these associations. The association between HC and increased risk of neuritic plaques weakened but remained significant even after controlling for ApoE genotype.
Conclusion:
This study suggested that HC was associated with increased severity of AD pathology, which could only be partially accounted for by ApoE genotype. The associations were not mediated by cerebrovascular conditions
Association between sleep duration and quality with rapid kidney function decline and development of chronic kidney diseases in adults with normal kidney function: The China health and retirement longitudinal study
Research have shown that sleep is associated with renal function. However, the potential effects of sleep duration or quality on kidney function in middle-aged and older Chinese adults with normal kidney function has rarely been studied. Our study aimed to investigate the association of sleep and kidney function in middle-aged and older Chinese adults. Four thousand and eighty six participants with an eGFR ≥60 ml/min/1.73 m2 at baseline were enrolled between 2011 and 2015 from the China Health and Retirement Longitudinal Study. Survey questionnaire data were collected from conducted interviews in the 2011. The eGFR was estimated from serum creatinine and/or cystatin C using the Chronic Kidney Disease Epidemiology Collaboration equations (CKD-EPI). The primary outcome was defined as rapid kidney function decline. Secondary outcome was defined as rapid kidney function decline with clinical eGFR of <60 ml/min/1.73 m2 at the exit visit. The associations between sleep duration, sleep quality and renal function decline or chronic kidney disease (CKD) were assessed based with logistic regression model. Our results showed that 244 (6.0%) participants developed rapid decline in kidney function, while 102 (2.5%) developed CKD. In addition, participants who had 3–7 days of poor sleep quality per week had higher risks of CKD development (OR 1.86, 95% CI 1.24–2.80). However, compared with those who had 6–8 h of night-time sleep, no significantly higher risks of rapid decline in kidney function was found among those who had <6 h or >8 h of night time sleep after adjustments for demographic, clinical, or psychosocial covariates. Furthermore, daytime nap did not present significant risk in both rapid eGFR decline or CKD development. In conclusion, sleep quality was significantly associated with the development of CKD in middle-aged and older Chinese adults with normal kidney function
MicroRNA and Putative Target Discoveries in Chrysanthemum Polyploidy Breeding
MicroRNAs (miRNAs), around 22 nucleotides (nt) in length, are a class of endogenous and noncoding RNA molecule that play an essential role in plant development, either by suppressing the transcription of target genes at a transcriptional level or inhibiting translation at a posttranscriptional level. To understand the roles of miRNAs and their target genes in chrysanthemum polyploidy breeding, three sRNA libraries of normal and abnormal embryos after hybridization were performed by RNA-Seq. As a result, a total of 170 miRNAs were identified and there are 41 special miRNAs in cross of paternal chromosome doubling, such as miR169b, miR440, and miR528-5p. miR164c and miR159a were highly expressed in a normal embryo at 18 days after pollination, suggesting the regulatory role at the late stage of embryonic development. miR172c was only detected in the normal embryo at 18 days after pollination, which means that miR172c mainly mediates gene expression in postembryonic development and these genes may promote embryo maturation. Other miRNAs, including miR414, miR2661, and miR5021, may regulate the genes participated in pathways of auxin response and energy metabolism; then they regulate the complex embryonic development together
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