853 research outputs found
Graph-Based Decoding Model for Functional Alignment of Unaligned fMRI Data
Aggregating multi-subject functional magnetic resonance imaging (fMRI) data
is indispensable for generating valid and general inferences from patterns
distributed across human brains. The disparities in anatomical structures and
functional topographies of human brains warrant aligning fMRI data across
subjects. However, the existing functional alignment methods cannot handle well
various kinds of fMRI datasets today, especially when they are not
temporally-aligned, i.e., some of the subjects probably lack the responses to
some stimuli, or different subjects might follow different sequences of
stimuli. In this paper, a cross-subject graph that depicts the
(dis)similarities between samples across subjects is used as a priori for
developing a more flexible framework that suits an assortment of fMRI datasets.
However, the high dimension of fMRI data and the use of multiple subjects makes
the crude framework time-consuming or unpractical. To address this issue, we
further regularize the framework, so that a novel feasible kernel-based
optimization, which permits nonlinear feature extraction, could be
theoretically developed. Specifically, a low-dimension assumption is imposed on
each new feature space to avoid overfitting caused by the
highspatial-low-temporal resolution of fMRI data. Experimental results on five
datasets suggest that the proposed method is not only superior to several
state-of-the-art methods on temporally-aligned fMRI data, but also suitable for
dealing `with temporally-unaligned fMRI data.Comment: 17 pages, 10 figures, Proceedings of the Association for the
Advancement of Artificial Intelligence (AAAI-20
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In vivo reprogramming of pancreatic acinar cells to three islet endocrine subtypes
Direct lineage conversion of adult cells is a promising approach for regenerative medicine. A major challenge of lineage conversion is to generate specific cell subtypes. The pancreatic islets contain three major hormone-secreting endocrine subtypes: insulin+ β-cells, glucagon+ α-cells, and somatostatin+ δ-cells. We previously reported that a combination of three transcription factors, Ngn3, Mafa, and Pdx1, directly reprograms pancreatic acinar cells to β-cells. We now show that acinar cells can be converted to δ-like and α-like cells by Ngn3 and Ngn3+Mafa respectively. Thus, three major islet endocrine subtypes can be derived by acinar reprogramming. Ngn3 promotes establishment of a generic endocrine state in acinar cells, and also promotes δ-specification in the absence of other factors. δ-specification is in turn suppressed by Mafa and Pdx1 during α- and β-cell induction. These studies identify a set of defined factors whose combinatorial actions reprogram acinar cells to distinct islet endocrine subtypes in vivo. DOI: http://dx.doi.org/10.7554/eLife.01846.00
Housing prices and household savings: evidence from urban China
Based on precautionary saving motives, this research develops a three-period life-cycle model to manifest the impact of housing prices on household savings in urban China. The theoretical model illustrates that the expected appreciation of housing prices at a household’s middle age leads to the increase in household savings at a household’s young age. Second, household savings at a household’s young age are positively associated with both expected educational and medical expenditures in a household’s middle age and pension expenditures at a household’s old age. Third, the expected housing prices crowd out educational and medical expenditures at a household’s middle age. With the panel data sets of China’s 31 provinces during 1996–2016, results suggest that the expected housing prices significantly interact with the current household savings. However, the influence of the expected housing prices on the current household savings is greater than that of the current household savings on the expected housing prices. Third, the expected expenditures of education, medical care and pension fuel up the current household savings. Meanwhile, the housing prices crowd out the expenditures of education, medical care and pension. Finally, data of the Urban Household Survey (UHS) over the period 2002–2007 show that the household head age has an effect of reverse U-shape on household savings. Accordingly, to prevent a housing bubble and promote household consumption, policy makers should curb housing price inflation by enacting appropriate countercyclical housing policies
The Reproducibility of Lists of Differentially Expressed Genes in Microarray Studies
Reproducibility is a fundamental requirement in scientific experiments and clinical contexts. Recent publications raise concerns about the reliability of microarray technology because of the apparent lack of agreement between lists of differentially expressed genes (DEGs). In this study we demonstrate that (1) such discordance may stem from ranking and selecting DEGs solely by statistical significance (P) derived from widely used simple t-tests; (2) when fold change (FC) is used as the ranking criterion, the lists become much more reproducible, especially when fewer genes are selected; and (3) the instability of short DEG lists based on P cutoffs is an expected mathematical consequence of the high variability of the t-values. We recommend the use of FC ranking plus a non-stringent P cutoff as a baseline practice in order to generate more reproducible DEG lists. The FC criterion enhances reproducibility while the P criterion balances sensitivity and specificity
Progress in molecular diagnosis and treatment of chronic mucocutaneous candidiasis
Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent or persistent infections with Candida of the skin, nails, and mucous membrane. It is a rare and severe disease resulting from autoimmune defects or immune dysregulations. Nonetheless, the diagnosis and treatment of CMC still pose significant challenges. Erroneous or delayed diagnoses remain prevalent, while the long-term utility of traditional antifungals often elicits adverse reactions and promotes the development of acquired resistance. Furthermore, disease relapse can occur during treatment with traditional antifungals. In this review, we delineate the advancements in molecular diagnostic and therapeutic approaches to CMC. Genetic and biomolecular analyses are increasingly employed as adjuncts to clinical manifestations and fungal examinations for accurate diagnosis. Simultaneously, a range of therapeutic interventions, including Janus kinase (JAK) inhibitors, hematopoietic stem cell transplantation (HSCT), cytokines therapy, novel antifungal agents, and histone deacetylase (HDAC) inhibitors, have been integrated into clinical practice. We aim to explore insights into early confirmation of CMC as well as novel therapeutic options for these patients
H-ensemble: An Information Theoretic Approach to Reliable Few-Shot Multi-Source-Free Transfer
Multi-source transfer learning is an effective solution to data scarcity by
utilizing multiple source tasks for the learning of the target task. However,
access to source data and model details is limited in the era of commercial
models, giving rise to the setting of multi-source-free (MSF) transfer learning
that aims to leverage source domain knowledge without such access. As a newly
defined problem paradigm, MSF transfer learning remains largely underexplored
and not clearly formulated. In this work, we adopt an information theoretic
perspective on it and propose a framework named H-ensemble, which dynamically
learns the optimal linear combination, or ensemble, of source models for the
target task, using a generalization of maximal correlation regression. The
ensemble weights are optimized by maximizing an information theoretic metric
for transferability. Compared to previous works, H-ensemble is characterized
by: 1) its adaptability to a novel and realistic MSF setting for few-shot
target tasks, 2) theoretical reliability, 3) a lightweight structure easy to
interpret and adapt. Our method is empirically validated by ablation studies,
along with extensive comparative analysis with other task ensemble and transfer
learning methods. We show that the H-ensemble can successfully learn the
optimal task ensemble, as well as outperform prior arts.Comment: AAAI 202
Ferritin light chain and squamous cell carcinoma antigen 1 are coreceptors for cellular attachment and entry of hepatitis B virus
Overexpression of squamous cell carcinoma antigen 1 (SCCA1) in hepatitis G2 (HepG2) and Chinese hamster ovary cells can increase hepatitis B virus (HBV) binding capacity by interacting with the preS1 domain of the HBV surface antigen. However, the magnitude of increase in binding capacity was higher by several orders in the former, indicating the existence of additional factor(s) produced by HepG2 cells, which facilitates HBV attachment. Ferritin light chain (FTL) was identified as the sole high hit candidate by screening human liver cDNA library using a bacterial two-hybrid system with either preS or SCCA1 as the bait. Subsequent in vitro protein–protein interaction assays confirmed the binding activity of FTL to both preS and SCCA1, as well as the formation of triple complex preS-FTL-SCCA1, and narrowed down the binding sites on FTL. In vitro overexpression of FTL could further enhance HBV attachment in both HepG2 and Chinese hamster ovary cells, which were already overexpressing SCCA1. Importantly, in vivo co-expression of human FTL and SCCA1 in mouse liver by means of tailvein hydrodynamic injection increased serum levels of HBV surface antigen transiently 24 hours post challenge with HBV-positive human sera, and a large amount of HBV core antigen-positive hepatocytes around blood vessels could be identified by immunohistochemical staining 48 hours post challenge. The data strongly suggest that FTL and SCCA1 may serve as coreceptors in HBV cellular attachment and virus entry into hepatocytes
Does graduate students' satisfaction with research laboratory affect their anxiety? Findings from a cross-sectional study at a Japanese university
This study investigates the relationship between graduate students' satisfaction with their research laboratories and their anxiety levels, using 2017 survey data from a Japanese university. Through correlation analysis and Structural Equation Modeling (SEM), this study examined how factors such as laboratory satisfaction, research outcome satisfaction, financial burden, and anxiety are interconnected. The findings reveal three key insights. First, graduate students report the highest levels of anxiety related to future prospects, employment, and economic conditions, and they are most likely to seek advice from parents or partners when experiencing anxiety. Second, satisfaction with the research laboratory significantly reduces anxiety, with the guidance methods of supervisors, interpersonal relationships, and research funding being the most influential factors. Satisfaction with research outcomes also plays a notable mediating role in this relationship. Third, seeking anxiety counseling is associated with increased anxiety levels, particularly when advice is sought from peers. These findings underscore the importance of the research laboratory environment in shaping graduate students' psychological wellbeing and provide a framework for understanding the mechanisms underlying anxiety development. This study highlights the need for universities to address laboratory dynamics and support systems to mitigate graduate student anxiety
Highway Value Iteration Networks
Value iteration networks (VINs) enable end-to-end learning for planning tasks
by employing a differentiable "planning module" that approximates the value
iteration algorithm. However, long-term planning remains a challenge because
training very deep VINs is difficult. To address this problem, we embed highway
value iteration -- a recent algorithm designed to facilitate long-term credit
assignment -- into the structure of VINs. This improvement augments the
"planning module" of the VIN with three additional components: 1) an "aggregate
gate," which constructs skip connections to improve information flow across
many layers; 2) an "exploration module," crafted to increase the diversity of
information and gradient flow in spatial dimensions; 3) a "filter gate"
designed to ensure safe exploration. The resulting novel highway VIN can be
trained effectively with hundreds of layers using standard backpropagation. In
long-term planning tasks requiring hundreds of planning steps, deep highway
VINs outperform both traditional VINs and several advanced, very deep NNs.Comment: ICML 202
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