2,203 research outputs found
Federated Learning with Diffusion Models for Privacy-Sensitive Vision Tasks
Diffusion models have shown great potential for vision-related tasks,
particularly for image generation. However, their training is typically
conducted in a centralized manner, relying on data collected from publicly
available sources. This approach may not be feasible or practical in many
domains, such as the medical field, which involves privacy concerns over data
collection. Despite the challenges associated with privacy-sensitive data, such
domains could still benefit from valuable vision services provided by diffusion
models. Federated learning (FL) plays a crucial role in enabling decentralized
model training without compromising data privacy. Instead of collecting data,
an FL system gathers model parameters, effectively safeguarding the private
data of different parties involved. This makes FL systems vital for managing
decentralized learning tasks, especially in scenarios where privacy-sensitive
data is distributed across a network of clients. Nonetheless, FL presents its
own set of challenges due to its distributed nature and privacy-preserving
properties. Therefore, in this study, we explore the FL strategy to train
diffusion models, paving the way for the development of federated diffusion
models. We conduct experiments on various FL scenarios, and our findings
demonstrate that federated diffusion models have great potential to deliver
vision services to privacy-sensitive domains
Modelling the Transition from Secondary to Tertiary Mathematics Education: Teacher and Lecturer Perspectives
The transition from school to tertiary study of mathematics is rightly coming under increasing scrutiny in research. This paper employs Tallâs model of the three worlds of mathematical thinking to examine key variables in teaching and learning as they relate to this transition. One key variable in the transition is clearly the teacher/lecturer and we consider the perspectives of both teachers and lecturers on teaching related matters relevant to upper secondary and first year tertiary calculus students. While this paper deals with a small part of the data from the project, which aims to model the transition, the results provide evidence of similarities and differences in the thinking of teachers and lecturers about the transition process. They also show that each group lacks a clear understanding of the issues involved in the transition from the otherâs perspective, and there is a great
need for improved communication between the two sectors
CT analysis of thoracolumbar body composition for estimating whole-body composition
Background
To evaluate the correlation between single- and multi-slice cross-sectional thoracolumbar and whole-body compositions.
Methods
We retrospectively included patients who underwent whole-body PETâCT scans from January 2016 to December 2019 at multiple institutions. A priori-developed, deep learning-based commercially available 3D U-Net segmentation provided whole-body 3D reference volumes and 2D areas of muscle, visceral fat, and subcutaneous fat at the upper, middle, and lower endplate of the individual T1âL5 vertebrae. In the derivation set, we analyzed the Pearson correlation coefficients of single-slice and multi-slice averaged 2D areas (waist and T12âL1) with the reference values. We then built prediction models using the top three correlated levels and tested the models in the validation set.
Results
The derivation and validation datasets included 203 (mean age 58.2years; 101 men) and 239 patients (mean age 57.8years; 80 men). The coefficients were distributed bimodally, with the first peak at T4 (coefficient, 0.78) and the second peak at L2-3 (coefficient 0.90). The top three correlations in the abdominal scan range were found for multi-slice waist averaging (0.92) and single-slice L3 and L2 (0.90, each), while those in the chest scan range were multi-slice T12âL1 averaging (0.89), single-slice L1 (0.89), and T12 (0.86). The model performance at the top three levels for estimating whole-body composition was similar in the derivation and validation datasets.
Conclusions
Single-slice L2â3 (abdominal CT range) and L1 (chest CT range) analysis best correlated with whole-body composition around 0.90 (coefficient). Multi-slice waist averaging provided a slightly higher correlation of 0.92.Key points
In single-slice analysis, the L2â3 and L1 levels had the closest correlations with whole-body composition.
Multi-slice waist averaging (0.92; correlation) showed a better correlation than the L2â3 single-slice analysis (0.90) in the abdomen.
Multi-slice T12âL1 averaging (0.89) provided a comparable correlation to the L1 level in the chest (0.89).This work was supported by the Korea Medical Device Development Fund grant funded by the Korean government (the Ministry of Science and ICT, the Ministry of Trade Industry and Energy, the Ministry of Health & Welfare, Republic of Korea, the Ministry of Food and Drug Safety) (Project Number: 202011A03). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Detection of an intermediate during the unfolding process of the dimeric ketosteroid isomerase
AbstractFailure to detect the intermediate in spite of its existence often leads to the conclusion that two-state transition in the unfolding process of the protein can be justified. In contrast to the previous equilibrium unfolding experiment fitted to a two-state model by circular dichroism and fluorescence spectroscopies, an equilibrium unfolding intermediate of a dimeric ketosteroid isomerase (KSI) could be detected by small angle X-ray scattering (SAXS) and analytical ultracentrifugation. The sizes of KSI were determined to be 18.7Ă
in 0M urea, 17.3Ă
in 5.2M urea, and 25.1Ă
in 7M urea by SAXS. The size of KSI in 5.2M urea was significantly decreased compared with those in 0M and 7M urea, suggesting the existence of a compact intermediate. Sedimentation velocity as obtained by ultracentrifugation confirmed that KSI in 5.2M urea is distinctly different from native and fully-unfolded forms. The sizes measured by pulse field gradient nuclear magnetic resonance (NMR) spectroscopy were consistent with those obtained by SAXS. Discrepancy of equilibrium unfolding studies between size measurement methods and optical spectroscopies might be due to the failure in detecting the intermediate by optical spectroscopic methods. Further characterization of the intermediate using 1H NMR spectroscopy and Kratky plot supported the existence of a partially-folded form of KSI which is distinct from those of native and fully-unfolded KSIs. Taken together, our results suggest that the formation of a compact intermediate should precede the association of monomers prior to the dimerization process during the folding of KSI
Mechanistic insights into non-immunosuppressive immunophilin ligands as potential antimalarial therapeutics
Identification of a novel mutation in a patient with pseudohypoparathyroidism type Ia
Pseudohypoparathyroidism type Ia (PHP Ia) is a disorder characterized by multiform hormonal resistance including parathyroid hormone (PTH) resistance and Albright hereditary osteodystrophy (AHO). It is caused by heterozygous inactivating mutations within the Gs alpha-encoding GNAS exons. A 9-year-old boy presented with clinical and laboratory abnormalities including hypocalcemia, hyperphosphatemia, PTH resistance, multihormone resistance and AHO (round face, short stature, obesity, brachydactyly and osteoma cutis) which were typical of PHP Ia. He had a history of repeated convulsive episodes that started from the age of 2 months. A cranial computed tomography scan showed bilateral calcifications in the basal ganglia and his intelligence quotient testing indicated mild mental retardation. Family history revealed that the patient's maternal relatives, including his grandmother and 2 of his mother's siblings, had features suggestive of AHO. Sequencing of the GNAS gene of the patient identified a heterozygous nonsense mutation within exon 11 (c.637 C>T). The C>T transversion results in an amino acid substitution from Gln to stop codon at codon 213 (p.Gln213*). To our knowledge, this is a novel mutation in GNAS
Prevalence of Dietary Supplement Use in Korean Children and Adolescents: Insights from Korea National Health and Nutrition Examination Survey 2007-2009
The purpose of this study was to estimate the prevalence of dietary supplement (DS) use in Korean children and adolescents and to examine the related factors associated with DS use from the 4th Korea National Health and Nutrition Examination Survey. Total 6,131 participants aged between 2 and 18 yr were included in the analysis. We estimated the prevalence of DS use mainly from the DS questionnaire data of the Nutrition Survey. Reported supplements were classified according to the Health Functional Food Code. We also assessed the relationship between DS use and anthropometry, socioeconomic factors, health behaviors, and chronic diseases. Approximately 34% of Korean children and adolescent was taking DS. Younger age (P = 0.003), higher household income (P < 0.001), presence of chronic diseases (P = 0.05), regular meal consumption (P = 0.002), frequent snack consumption (P = 0.001), and normal body mass index rather than overweight (P = 0.10) or obesity (P = 0.03) were associated with the DS use after adjustment for related factors. Vitamin/mineral supplements (343.5/103 persons) were the most commonly taken DS in Korean children and adolescents, followed by Omega-3 (28.8), ginseng (18.3), colostrums (14.1) and chlorella/spirulina (10.0). In conclusion, DS use is common as much as in 34% of Korean children and adolescents and is associated with age, household income level, chronic diseases, meal regularity, and obesity status
Sucrose preferentially promotes expression of OsWRKY7 and OsPR10a to enhance defense response to blast fungus in rice
Sucrose controls various developmental and metabolic processes in plants. It also functions as a signaling molecule in the synthesis of carbohydrates, storage proteins, and anthocyanins, as well as in floral induction and defense response. We found that sucrose preferentially induced OsWRKY7, whereas other sugars (such as mannitol, glucose, fructose, galactose, and maltose) did not have the same effect. A hexokinase inhibitor mannoheptulose did not block the effect of sucrose, which is consequently thought to function directly. MG132 inhibited sucrose induction, suggesting that a repressor upstream of OsWRKY7 is degraded by the 26S proteasome pathway. The 3-kb promoter sequence of OsWRKY7 was preferentially induced by sucrose in the luciferase system. Knockout mutants of OsWRKY7 were more sensitive to the rice blast fungus Magnaporthe oryzae, whereas the overexpression of OsWRKY7 enhanced the resistance, indicating that this gene is a positive regulator in the plant defense against this pathogen. The luciferase activity driven by the OsPR10a promoter was induced by OsWRKY7 and this transcription factor bound to the promoter region of OsPR10a, suggesting that OsWRKY7 directly controls the expression of OsPR10a. We conclude that sucrose promotes the transcript level of OsWRKY7, thereby increasing the expression of OsPR10a for the defense response in rice
Feeling superior or deprived? Attitudes and underlying mentalities of residents towards Mainland Chinese tourists
The exponential increase in the number of Mainland Chinese tourists (MCTs) and their sudden influx to popular destinations worldwide have resulted in increasingly frequent media reports on their behaviours and encounters with hosts. However, the academic literature has inadequately analysed resident attitudes towards this surging and, in a few destinations, dominant group. The current study addresses this gap by examining the attitudes and mentalities of Hong Kong (HK) residents towards MCTs and revealing their underlying psychological mechanism. A total of 39 semi-structured interviews demonstrate that unfavourable attitudes towards MCTs have exceeded neutral or positive attitudes. Moreover, HK residents share two intertwined mentalities â sense of superiority and feeling of deprivation. Findings are discussed under the social identity meta-theoretical framework, and a cyclic psychological mechanism of âsocial categorisationâsocial identityâsocial comparisonâ is identified underlying resident attitude and community mentality formation
Methylsulfonylmethane Suppresses Breast Cancer Growth by Down-Regulating STAT3 and STAT5b Pathways
Breast cancer is the most aggressive form of all cancers, with high incidence and mortality rates. The purpose of the present study was to investigate the molecular mechanism by which methylsulfonylmethane (MSM) inhibits breast cancer growth in mice xenografts. MSM is an organic sulfur-containing natural compound without any toxicity. In this study, we demonstrated that MSM substantially decreased the viability of human breast cancer cells in a dose-dependent manner. MSM also suppressed the phosphorylation of STAT3, STAT5b, expression of IGF-1R, HIF-1Îą, VEGF, BrK, and p-IGF-1R and inhibited triple-negative receptor expression in receptor-positive cell lines. Moreover, MSM decreased the DNA-binding activities of STAT5b and STAT3, to the target gene promoters in MDA-MB 231 or co-transfected COS-7 cells. We confirmed that MSM significantly decreased the relative luciferase activities indicating crosstalk between STAT5b/IGF-1R, STAT5b/HSP90Îą, and STAT3/VEGF. To confirm these findings in vivo, xenografts were established in Balb/c athymic nude mice with MDA-MB 231 cells and MSM was administered for 30 days. Concurring to our in vitro analysis, these xenografts showed decreased expression of STAT3, STAT5b, IGF-1R and VEGF. Through in vitro and in vivo analysis, we confirmed that MSM can effectively regulate multiple targets including STAT3/VEGF and STAT5b/IGF-1R. These are the major molecules involved in tumor development, progression, and metastasis. Thus, we strongly recommend the use of MSM as a trial drug for treating all types of breast cancers including triple-negative cancers
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