223 research outputs found
Increase in testosterone levels is related to a lower risk of conversion of prediabetes to manifest diabetes in prediabetic males
Background: Testosterone plays an important role in the regulation of glucose metabolism. While earlier studies have shown that it has a protective effect in males, unfavorable effects of testosterone on glucose metabolism have been reported in females; however, whether there is a sex-specific relationship between testosterone and glucose metabolism in patients with prediabetes has not been investigated in detail hitherto.
Methods: This cross-sectional analysis investigated 423 males and 287 females with diagnosed prediabetes. Detailed assessment of their metabolic profiles was performed, including a 2âh oral glucose tolerance test (OGTT), HbA1c levels, calculation of insulin resistance with homeostatic model assessment for insulin resistance (HOMA-IR), assessment of lipid metabolism, anthropometric parameters and the fatty liver index (FLI). By using Spearman's correlation test, we investigated the sex-specific relationship between testosterone and metabolism in the prediabetic individuals.
Results: In the present study, prediabetic females (mean age 58.6 years, confidence interval [CI: 57.6 y; 59.5 y]) were characterized by lower fasting plasma glucose levels (104.2 mg/dl [CI: 103.0 mg/dl; 105.4 mg/dl] vs. 106.9 mg/dl [CI: 106.0 mg/dl; 107.8 mg/dl]) and a lower FLI (49.5 [CI: 45.7; 53.2] vs. 58.8 [CI: 55.8; 61.8]), but presented with a higher risk of developing manifest type 2 diabetes in the next 10 years (FINDRISK score: 17.6 [CI: 17.1; 18.1] vs. 16.1 [CI: 15.7; 16.5]) when compared to prediabetic males (mean age: 58.04 years [CI: 57.0 y; 59.1 y]). Testosterone was negatively related to insulin resistance (HOMA-IR: Spearman's Ï: -0.33, p < 0.01), 2âh stimulated glucose levels during the OGTT (Ï = -0.18, p < 0.01), HbA1c levels (Ï = -0.13, p < 0.05), FLI and BMI in prediabetic males; however, no relationship between testosterone and metabolic parameters could be found in prediabetic females.
Conclusion: The increase of testosterone levels in males was related to a more favorable glucose metabolism, including lower HbA1c, lower stimulated glucose levels and higher insulin sensitivity; however, in prediabetic females, testosterone was not related to glucose metabolism
Impact Factor: outdated artefact or stepping-stone to journal certification?
A review of Garfield's journal impact factor and its specific implementation
as the Thomson Reuters Impact Factor reveals several weaknesses in this
commonly-used indicator of journal standing. Key limitations include the
mismatch between citing and cited documents, the deceptive display of three
decimals that belies the real precision, and the absence of confidence
intervals. These are minor issues that are easily amended and should be
corrected, but more substantive improvements are needed. There are indications
that the scientific community seeks and needs better certification of journal
procedures to improve the quality of published science. Comprehensive
certification of editorial and review procedures could help ensure adequate
procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table
A Virtual Agent as Vocabulary Trainer: Iconic Gestures Help to Improve Learnersâ Memory Performance
An important and often laborious task in foreign language acquisition is vocabulary learning. Research has repeatedly demonstrated that performing iconic gestures together with novel words has a beneficial effect on learning performance. Can these findings be transferred onto virtual agents applied in gesture-supported vocabulary training? We present a study investigating whether iconic gestures performed by a virtual agent and imitated by learners have an impact on verbal memory for words in a foreign language. In a within-subject design we compared participantsâ memory performance achieved with the help of a virtual agent and those achieved with the help of a human trainer regarding both short-term learning effects and long-term decay effects. The overall results demonstrate improved memory scores when participants learned with a virtual agent. Especially high performers could profit from gesture-supported training with a virtual agent
Automated protein resonance assignments of magic angle spinning solid-state NMR spectra of ÎČ1 immunoglobulin binding domain of protein G (GB1)
Magic-angle spinning solid-state NMR (MAS SSNMR) represents a fast developing experimental technique with great potential to provide structural and dynamics information for proteins not amenable to other methods. However, few automated analysis tools are currently available for MAS SSNMR. We present a methodology for automating protein resonance assignments of MAS SSNMR spectral data and its application to experimental peak lists of the ÎČ1 immunoglobulin binding domain of protein G (GB1) derived from a uniformly 13C- and 15N-labeled sample. This application to the 56 amino acid GB1 produced an overall 84.1% assignment of the N, CO, CA, and CB resonances with no errors using peak lists from NCACX 3D, CANcoCA 3D, and CANCOCX 4D experiments. This proof of concept demonstrates the tractability of this problem
Magnetic resonance imaging in children: common problems and possible solutions for lung and airways imaging
Pediatric chest MRI is challenging. High-resolution
scans of the lungs and airways are compromised by long imaging
times, low lung proton density and motion. Low signal
is a problem of normal lung. Lung abnormalities commonly
cause increased signal intenstities. Among the most important
factors for a successful MRI is patient cooperation, so the long
acquisition times make patient preparation crucial. Children
usually have problems with long breath-holds and with the
concept of quiet breathing. Young children are even more
challenging because of higher cardiac and respiratory rates
giving motion blurring. For these reasons, CT has often been
preferred over MRI for chest pediatric imaging. Despite its
drawbacks, MRI also has advantages over CT, which justifies
its further development and clinical use. The most important
advantage is the absence of ionizing radiation, which allows
frequent scanning for short- and long-term follow-up studie
Probabilistic Interaction Network of Evidence Algorithm and its Application to Complete Labeling of Peak Lists from Protein NMR Spectroscopy
The process of assigning a finite set of tags or labels to a collection of observations, subject to side conditions, is notable for its computational complexity. This labeling paradigm is of theoretical and practical relevance to a wide range of biological applications, including the analysis of data from DNA microarrays, metabolomics experiments, and biomolecular nuclear magnetic resonance (NMR) spectroscopy. We present a novel algorithm, called Probabilistic Interaction Network of Evidence (PINE), that achieves robust, unsupervised probabilistic labeling of data. The computational core of PINE uses estimates of evidence derived from empirical distributions of previously observed data, along with consistency measures, to drive a fictitious system M with Hamiltonian H to a quasi-stationary state that produces probabilistic label assignments for relevant subsets of the data. We demonstrate the successful application of PINE to a key task in protein NMR spectroscopy: that of converting peak lists extracted from various NMR experiments into assignments associated with probabilities for their correctness. This application, called PINE-NMR, is available from a freely accessible computer server (http://pine.nmrfam.wisc.edu). The PINE-NMR server accepts as input the sequence of the protein plus user-specified combinations of data corresponding to an extensive list of NMR experiments; it provides as output a probabilistic assignment of NMR signals (chemical shifts) to sequence-specific backbone and aliphatic side chain atoms plus a probabilistic determination of the protein secondary structure. PINE-NMR can accommodate prior information about assignments or stable isotope labeling schemes. As part of the analysis, PINE-NMR identifies, verifies, and rectifies problems related to chemical shift referencing or erroneous input data. PINE-NMR achieves robust and consistent results that have been shown to be effective in subsequent steps of NMR structure determination
Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study
Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p<0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p<0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved
CASA: An Efficient Automated Assignment of Protein Mainchain NMR Data Using an Ordered Tree Search Algorithm
Rapid analysis of protein structure, interaction, and dynamics requires fast and automated assignments of 3D protein backbone triple-resonance NMR spectra. We introduce a new depth-first ordered tree search method of automated assignment, CASA, which uses hand-edited peak-pick lists of a flexible number of triple resonance experiments. The computer program was tested on 13 artificially simulated peak lists for proteins up to 723 residues, as well as on the experimental data for four proteins. Under reasonable tolerances, it generated assignments that correspond to the ones reported in the literature within a few minutes of CPU time. The program was also tested on the proteins analyzed by other methods, with both simulated and experimental peaklists, and it could generate good assignments in all relevant cases. The robustness was further tested under various situations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43050/1/10858_2005_Article_4079.pd
Climate vs. topography â spatial patterns of plant species diversity and endemism on a high-elevation island
Climate and topography are among the most fundamental drivers of plant diversity. Here, we
assessed the importance of climate and topography in explaining diversity patterns of species richness,
endemic richness and endemicity on the landscape scale of an oceanic island and evaluated the
independent contribution of climatic and topographic variables to spatial diversity patterns.
2. We constructed a presence/absence matrix of perennial endemic and native vascular plant species
(including subspecies) in 890 plots on the environmentally very heterogeneous island of La Palma,
Canary Islands. Species richness, endemic richness and endemicity were recorded, interpolated and
related to climate (i.e. variables describing temperature, precipitation, variability and climatic rarity)
and topography (i.e. topographic complexity, solar radiation, geologic age, slope and aspect). We
used multimodel inference, spatial autoregressive models, variance partitioning and linear regression
kriging as statistical methods.
3. Species richness is best explained by both climatic and topographic variables. Topographic
variables (esp. topographic complexity and solar radiation) explain endemic richness, and climatic
variables (esp. elevation/temperature and rainfall seasonality) explain endemicity. Spatial patterns of
species richness, endemic richness and endemicity were in part geographically decoupled from each
other.
4. Synthesis. We identified several topography-dependent processes ranging from evolutionary processes
(micro-refugia, in situ speciation, pre-adaptation to rupicolous conditions, dispersal limitations)
to human-induced influences (introduced herbivores, fire, land use) that possibly shape the
endemic richness pattern of La Palma. In contrast, climate mainly drives endemicity, which is connected
to ecological speciation and specialization to local conditions. We highlight the importance
of incorporating climatic variability into future studies of plant species diversity and endemism. The
spatial incongruence in hot spots of species richness, endemic richness and endemicity emphasizes
the need for an integrated conservation approach acknowledging different diversity measures to protect
the complete spectrum of diversity. High-elevation islands such as La Palma are highly suitable
to study drivers of diversity and endemism, as they offer environmental gradients of continental
magnitude on the landscape scale of a single climatic mini-continent and a large array of in situspeciated
endemics
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