823 research outputs found
Utility of the hypertriglyceridemic waist phenotype in the cardiometabolic risk assessment of youth stratified by body mass index
Background: It is unclear whether the Hypertriglyceridemic Waist Phenotype can be used to identify those at most risk of cardiometabolic disorders.
Objectives: The utility of the Hypertriglyceridemic Waist Phenotype (HTWP) as a useful predictor of cardiometabolic risk in youth stratified by body mass index (BMI) was assessed.
Methods: Three hundred and eighty seven children (12-17.5 years) were used within this cross-sectional study. Participants were classified as normal weight or overweight/obese according to the IOTF criteria. The HTWP phenotype was defined as having a waist circumference ≥ 90th percentile for age and gender with concomitant triglyceride concentrations ≥ 1.24 mmol/L. Cardiometabolic risk profiles were compared using MANCOVA.
Results: Normal weight participants with the HTWP had significantly higher levels of C-reactive protein 2.6 ± 0.4 vs. 1.6 ± 0.3 mg/L (P < 0.05) and cardiometabolic risk scores (1.3 ± 0.3 vs. -0.7 ± 0.2 and 2.1 ± 0.4 vs. -0.5 ± 0.2; both P < 0.05) compared to those of a normal weight without the HTWP. Overweight/obese participants with the HTWP had significantly higher C-reactive protein levels (3.5 ± 0.6 vs. 2.6 ± 0.5; P < 0.05) as well as both cardiometabolic risk scores (1.6 ± 0.6 vs. 0.9 ± 0.2 and 2.2 ± 0.6 vs. 0.8 ± 0.2; both P < 0.001) when compared to overweight/obese participants without the HTWP.
Conclusions:
The HTWP may serve as a simple and clinically useful approach to identify youth at increased cardiometabolic risk
Photoswitchable diacylglycerols enable optical control of protein kinase C.
Increased levels of the second messenger lipid diacylglycerol (DAG) induce downstream signaling events including the translocation of C1-domain-containing proteins toward the plasma membrane. Here, we introduce three light-sensitive DAGs, termed PhoDAGs, which feature a photoswitchable acyl chain. The PhoDAGs are inactive in the dark and promote the translocation of proteins that feature C1 domains toward the plasma membrane upon a flash of UV-A light. This effect is quickly reversed after the termination of photostimulation or by irradiation with blue light, permitting the generation of oscillation patterns. Both protein kinase C and Munc13 can thus be put under optical control. PhoDAGs control vesicle release in excitable cells, such as mouse pancreatic islets and hippocampal neurons, and modulate synaptic transmission in Caenorhabditis elegans. As such, the PhoDAGs afford an unprecedented degree of spatiotemporal control and are broadly applicable tools to study DAG signaling
Machine-learning of atomic-scale properties based on physical principles
We briefly summarize the kernel regression approach, as used recently in
materials modelling, to fitting functions, particularly potential energy
surfaces, and highlight how the linear algebra framework can be used to both
predict and train from linear functionals of the potential energy, such as the
total energy and atomic forces. We then give a detailed account of the Smooth
Overlap of Atomic Positions (SOAP) representation and kernel, showing how it
arises from an abstract representation of smooth atomic densities, and how it
is related to several popular density-based representations of atomic
structure. We also discuss recent generalisations that allow fine control of
correlations between different atomic species, prediction and fitting of
tensorial properties, and also how to construct structural kernels---applicable
to comparing entire molecules or periodic systems---that go beyond an additive
combination of local environments
Artificial Neural Network Inference (ANNI): A Study on Gene-Gene Interaction for Biomarkers in Childhood Sarcomas
Objective: To model the potential interaction between previously identified biomarkers in children sarcomas using artificial neural network inference (ANNI).
Method: To concisely demonstrate the biological interactions between correlated genes in an interaction network map, only 2 types of sarcomas in the children small round blue cell tumors (SRBCTs) dataset are discussed in this paper. A backpropagation neural network was used to model the potential interaction between genes. The prediction weights and signal directions were used to model the strengths of the interaction signals and the direction of the interaction link between genes. The ANN model was validated using Monte Carlo cross-validation to minimize the risk of over-fitting and to optimize generalization ability of the model.
Results: Strong connection links on certain genes (TNNT1 and FNDC5 in rhabdomyosarcoma (RMS); FCGRT and OLFM1 in Ewing’s sarcoma (EWS)) suggested their potency as central hubs in the interconnection of genes with different functionalities. The results showed that the RMS patients in this dataset are likely to be congenital and at low risk of cardiomyopathy development. The EWS patients are likely to be complicated by EWS-FLI fusion and deficiency in various signaling pathways, including Wnt, Fas/Rho and intracellular oxygen.
Conclusions: The ANN network inference approach and the examination of identified genes in the published literature within the context of the disease highlights the substantial influence of certain genes in sarcomas
Discrete population balance models of random agglomeration and cleavage in polymer pyrolysis
The processes of random agglomeration and cleavage (both of which are important for the development of new models of polymer combustion, but are also applicable in a wide range of fields including atmospheric physics, radiation modelling and astrophysics) are analysed using population balance methods. The evolution of a discrete distribution of particles is considered within this framework, resulting in a set of ordinary differential equations for the individual particle concentrations. Exact solutions for these equations are derived, together with moment generating functions. Application of the discrete Laplace transform (analogous to the Z-transform) is found to be effective in these problems, providing both exact solutions for particle concentrations and moment generating functions. The combined agglomeration-cleavage problem is also considered. Unfortunately, it has been impossible to find an exact solution for the full problem, but a stable steady state has been identified and computed
Cell Cycle- and Cancer-Associated Gene Networks Activated by Dsg2: Evidence of Cystatin A Deregulation and a Potential Role in Cell-Cell Adhesion
This work was supported by grants from
the National Institutes of Health (Mahoney,
R01AR056067; Riobo, RO1 GM088256). The
funders had no role in study design, data collection
and analysis, decision to publish, or preparation of
the manuscript
Cerebellar Integrity in the Amyotrophic Lateral Sclerosis - Frontotemporal Dementia Continuum
Amyotrophic lateral sclerosis (ALS) and behavioural variant frontotemporal dementia (bvFTD) are multisystem neurodegenerative disorders that manifest overlapping cognitive, neuropsychiatric and motor features. The cerebellum has long been known to be crucial for intact motor function although emerging evidence over the past decade has attributed cognitive and neuropsychiatric processes to this structure. The current study set out i) to establish the integrity of cerebellar subregions in the amyotrophic lateral sclerosis-behavioural variant frontotemporal dementia spectrum (ALS-bvFTD) and ii) determine whether specific cerebellar atrophy regions are associated with cognitive, neuropsychiatric and motor symptoms in the patients. Seventy-eight patients diagnosed with ALS, ALS-bvFTD, behavioural variant frontotemporal dementia (bvFTD), most without C9ORF72 gene abnormalities, and healthy controls were investigated. Participants underwent cognitive, neuropsychiatric and functional evaluation as well as structural imaging using voxel-based morphometry (VBM) to examine the grey matter subregions of the cerebellar lobules, vermis and crus. VBM analyses revealed: i) significant grey matter atrophy in the cerebellum across the whole ALS-bvFTD continuum; ii) atrophy predominantly of the superior cerebellum and crus in bvFTD patients, atrophy of the inferior cerebellum and vermis in ALS patients, while ALS-bvFTD patients had both patterns of atrophy. Post-hoc covariance analyses revealed that cognitive and neuropsychiatric symptoms were particularly associated with atrophy of the crus and superior lobule, while motor symptoms were more associated with atrophy of the inferior lobules. Taken together, these findings indicate an important role of the cerebellum in the ALS-bvFTD disease spectrum, with all three clinical phenotypes demonstrating specific patterns of subregional atrophy that associated with different symptomology
Satisfaction with care as a quality-of-life predictor for stroke patients and their caregivers
Purpose: We sought to identify indicators associated with the quality of life (QoL) of stroke patients and caregivers. Methods: The cross-sectional study was conducted at nine Dutch stroke service facilities involving 251 stroke patients and their caregivers. We used the EuroQol (EQ-5D) and Satisfaction with Stroke Care questionnaires, and included the variables (1) disability at hospital admission, (2) length of hospital stay, (3) demographic data, and (4) caregivers' relationship with stroke patients. The Actor-Partner (patient-caregiver) Interdependence Model (APIM) was used to examine dependence between patients' and caregivers' QoL scores through dyad membership. Results: Patients' age was significantly related to their QoL, and caregivers' age and educational level were significantly related to their QoL. Patients' disability on hospital admission and length of stay were associated with patients' QoL, and their disability on admission was related to caregivers' QoL. No relationship was found between length of stay and caregivers' QoL. Satisfaction with care was associated with both patients' and caregivers' QoL. Conclusions: The APIM distinguished the different roles of patients and caregivers while acknowledging the interdependence of their QoL scores. Satisfaction with care was identified as important indicator of stroke patients' and caregivers' QoL
The influence of hydrological regimes on sex ratios and spatial segregation of the sexes in two dioecious riparian shrub species in northern Sweden
River management practices have altered the hydrological regimes of many rivers and also altered the availability of regeneration niches for riparian species. We investigated the impact of changed hydrological regimes on the sex ratios and the Spatial Segregation of the Sexes (SSS) in the dioecious species Salix myrsinifolia Salisb.–phylicifolia L. and S. lapponum L. by studying the free-flowing Vindel River and the regulated Ume River in northern Sweden. We surveyed sex ratios of these species in 12 river reaches on the Vindel River and in 17 reaches on the Ume River. In addition, we surveyed the sex and location above mean river stage of 1,002 individuals across both river systems to investigate the SSS of both species. Cuttings were collected from male and female individuals of S. myrsinifolia–phylicifolia from both rivers and subjected to four different water table regimes in a greenhouse experiment to investigate growth response between the sexes. We found an M/F sex ratio in both river systems similar to the regional norm of 0.62 for S. myrsinifolia–phylicifolia and of 0.42 for S. lapponum. We found no evidence of SSS in either the free-flowing Vindel River or the regulated Ume River. In the greenhouse experiment, hydrological regime had a significant effect on shoot and root dry weight and on root length. Significantly higher shoot dry weights were found in females than in males and significantly different shoot and root dry weights were found between cuttings taken from the two rivers. We concluded that changed hydrological regimes are likely to alter dimensions of the regeneration niche and therefore to influence sex ratios and SSS at an early successional stage, making it difficult to find clear spatial patterns once these species reach maturity and can be sexed
Swimming with Predators and Pesticides: How Environmental Stressors Affect the Thermal Physiology of Tadpoles
To forecast biological responses to changing environments, we need to understand how a species’s physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4uC higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5uC, while exposure to the herbicide marginally lowered Topt by 0.4uC. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5uC higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.Peer reviewe
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