468 research outputs found
PERFORMANCE OF TIMBER BOARD MODELS FOR PREDICTION OF LOCAL BENDING STIFFNESS AND STRENGTH – WITH APPLICATION ON DOUGLAS FIR SAWN TIMBER
Efficient utilization of structural timber requires accurate methods for machine strength grading. One of the most accurate methods presented this far is based on data of local fiber orientation on board surfaces, obtained from laser scanning. In this paper, two potential improvements of this method are examined. The first one consists of replacing a model based on simple integration over cross sections of boards for calculation of local bending stiffness by a 3D solid finite element (FE) model from which local bending stiffness is derived. The second improvement concerns replacement of a simple model for the fiber orientation in the interior of board by a more advanced one taking location of pith and growth direction of knots into account. Application of the alternative models on a sample of more than 200 Douglas fir boards, size 40 mm X 100 mm X 3000 mm, cut from large logs, show that each of the evaluated model improvements contributes to improved grading accuracy. When local bending stiffness is calculated utilizing the herein suggested FE model in combination with the improved model of fiber orientation in the interior of boards, a coefficient of determination to bending strength as high as 0.76 is obtained. For comparison, a coefficient of determination of 0.71 is obtain using the simpler original models
Association of faecal elastase 1 with non-fasting triglycerides in type 2 diabetes.
AIMS: Intestinal absorption of esterified fatty acids depends on exocrine pancreatic function and influences plasma triglycerides levels. The aim was to investigate the association of reduced exocrine pancreatic function (low fecal elastase-1; FE1) with plasma triglycerides in type 2 diabetes and controls without diabetes. METHODS: FE1 (μg/g stool) and non-fasting plasma triglyceride measurements were undertaken in 544 type 2 diabetes patients (age: 63 ± 8 years) randomly selected from diabetes registers in Cambridgeshire (UK), and 544 matched controls (age, sex, practice) without diabetes. Linear regression models were fitted using FE1 as dependent and log-triglycerides as independent variable adjusting for sex, age, body mass index, alcohol consumption, serum lipase, HbA1c, and smoking. RESULTS: FE1 concentrations were lower (mean ± SD: 337 ± 204 vs. 437 ± 216 μg/g, p < 0.05) and plasma triglycerides were higher (geometric mean */: standard deviation factor: 2.2*/:1.9 vs. 1.6*/:1.8 mmol/l, p < 0.05) in type 2 diabetes compared to controls, respectively. Within the category of type 2 diabetes and controls separately, a 10% increase in plasma triglycerides was associated with 4.5 μg/g higher FE1 concentrations (p < 0.01) after adjusting for confounders. In contrast, in diabetes patients and controls with pathological FE1 (<100 μg/g), low FE1 levels were associated with high plasma triglycerides (significant only in controls). CONCLUSIONS: Non-fasting triglycerides were positively related to FE1 in both type 2 diabetes and controls suggesting that impairment of exocrine pancreas function is influencing plasma triglycerides. Marked loss of exocrine pancreatic function had the opposite effect, resulting in higher levels of plasma triglycerides.The analysis of the Cambridgeshire study was supported by an unrestricted grant from AstraZeneca, Sweden.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.pan.2016.03.01
Specified Species in Gingival Crevicular Fluid Predict Bacterial Diversity
BACKGROUND: Analysis of gingival crevicular fluid (GCF) samples may give information of unattached (planktonic) subgingival bacteria. Our study represents the first one targeting the identity of bacteria in GCF. METHODOLOGY/PRINCIPAL FINDINGS: We determined bacterial species diversity in GCF samples of a group of periodontitis patients and delineated contributing bacterial and host-associated factors. Subgingival paper point (PP) samples from the same sites were taken for comparison. After DNA extraction, 16S rRNA genes were PCR amplified and DNA-DNA hybridization was performed using a microarray for over 300 bacterial species or groups. Altogether 133 species from 41 genera and 8 phyla were detected with 9 to 62 and 18 to 64 species in GCF and PP samples, respectively, per patient. Projection to latent structures by means of partial least squares (PLS) was applied to the multivariate data analysis. PLS regression analysis showed that species of genera including Campylobacter, Selenomonas, Porphyromonas, Catonella, Tannerella, Dialister, Peptostreptococcus, Streptococcus and Eubacterium had significant positive correlations and the number of teeth with low-grade attachment loss a significant negative correlation to species diversity in GCF samples. OPLS/O2PLS discriminant analysis revealed significant positive correlations to GCF sample group membership for species of genera Campylobacter, Leptotrichia, Prevotella, Dialister, Tannerella, Haemophilus, Fusobacterium, Eubacterium, and Actinomyces. CONCLUSIONS/SIGNIFICANCE: Among a variety of detected species those traditionally classified as Gram-negative anaerobes growing in mature subgingival biofilms were the main predictors for species diversity in GCF samples as well as responsible for distinguishing GCF samples from PP samples. GCF bacteria may provide new prospects for studying dynamic properties of subgingival biofilms
A metabolomics based molecular pathway analysis for how the SGLT2-inhibitor dapagliflozin may slow kidney function decline in patients with diabetes
Aim: To investigate which metabolic pathways are targeted by the sodium-glucose co-transporter-2 inhibitor dapagliflozin to explore the molecular processes involved in its renal protective effects. Methods: An unbiased mass spectrometry plasma metabolomics assay was performed on baseline and follow-up (week 12) samples from the EFFECT II trial in patients with type 2 diabetes with non-alcoholic fatty liver disease receiving dapagliflozin 10 mg/day (n = 19) or placebo (n = 6). Transcriptomic signatures from tubular compartments were identified from kidney biopsies collected from patients with diabetic kidney disease (DKD) (n = 17) and healthy controls (n = 30) from the European Renal cDNA Biobank. Serum metabolites that significantly changed after 12 weeks of dapagliflozin were mapped to a metabolite-protein interaction network. These proteins were then linked with intra-renal transcripts that were associated with DKD or estimated glomerular filtration rate (eGFR). The impacted metabolites and their protein-coding transcripts were analysed for enriched pathways. Results: Of all measured (n = 812) metabolites, 108 changed (P < 0.05) during dapagliflozin treatment and 74 could be linked to 367 unique proteins/genes. Intra-renal mRNA expression analysis of the genes encoding the metabolite-associated proteins using kidney biopsies resulted in 105 genes that were significantly associated with eGFR in patients with DKD, and 135 genes that were differentially expressed between patients with DKD and controls. The combination of metabolites and transcripts identified four enriched pathways that were affected by dapagliflozin and associated with eGFR: glycine degradation (mitochondrial function), TCA cycle II (energy metabolism), L-carnitine biosynthesis (energy metabolism) and superpathway of citrulline metabolism (nitric oxide synthase and endothelial function). Conclusion: The observed molecular pathways targeted by dapagliflozin and associated with DKD suggest that modifying molecular processes related to energy metabolism, mitochondrial function and endothelial function may contribute to its renal protective effect.</p
Virulence and Pathogenicity Properties of Aggregatibacter actinomycetemcomitans
Aggregatibacter actinomycetemcomitans is a periodontal pathogen
colonizing the oral cavity of a large proportion of the human
population. It is equipped with several potent virulence factors that
can cause cell death and induce or evade inflammation. Because of the
large genetic diversity within the species, both harmless and highly
virulent genotypes of the bacterium have emerged. The oral condition and
age, as well as the geographic origin of the individual, influence the
risk to be colonized by a virulent genotype of the bacterium. In the
present review, the virulence and pathogenicity properties of A. actinomycetemcomitans will be addressed
Attentive Learning of Sequential Handwriting Movements: A Neural Network Model
Defense Advanced research Projects Agency and the Office of Naval Research (N00014-95-1-0409, N00014-92-J-1309); National Science Foundation (IRI-97-20333); National Institutes of Health (I-R29-DC02952-01)
Dynamical principles in neuroscience
Dynamical modeling of neural systems and brain functions has a history of success over the last half century. This includes, for example, the explanation and prediction of some features of neural rhythmic behaviors. Many interesting dynamical models of learning and memory based on physiological experiments have been suggested over the last two decades. Dynamical models even of consciousness now exist. Usually these models and results are based on traditional approaches and paradigms of nonlinear dynamics including dynamical chaos. Neural systems are, however, an unusual subject for nonlinear dynamics for several reasons: (i) Even the simplest neural network, with only a few neurons and synaptic connections, has an enormous number of variables and control parameters. These make neural systems adaptive and flexible, and are critical to their biological function. (ii) In contrast to traditional physical systems described by well-known basic principles, first principles governing the dynamics of neural systems are unknown. (iii) Many different neural systems exhibit similar dynamics despite having different architectures and different levels of complexity. (iv) The network architecture and connection strengths are usually not known in detail and therefore the dynamical analysis must, in some sense, be probabilistic. (v) Since nervous systems are able to organize behavior based on sensory inputs, the dynamical modeling of these systems has to explain the transformation of temporal information into combinatorial or combinatorial-temporal codes, and vice versa, for memory and recognition. In this review these problems are discussed in the context of addressing the stimulating questions: What can neuroscience learn from nonlinear dynamics, and what can nonlinear dynamics learn from neuroscience?This work was supported by NSF Grant No. NSF/EIA-0130708, and Grant No. PHY 0414174; NIH Grant No. 1 R01 NS50945 and Grant No. NS40110; MEC BFI2003-07276, and FundaciĂłn BBVA
Ins and Outs of Cerebellar Modules
The modular concept of cerebellar connections has been advocated in the lifetime work of Jan Voogd. In this concept, a cerebellar module is defined as the conglomerate of one or multiple and non-adjacent, parasagittally arranged zones of Purkinje cells, their specific projection to a well-defined region of the cerebellar nuclei, and the climbing fiber input to these zones by a well-defined region of the inferior olivary complex. The modular organization of these olivo-cortico-nuclear connections is further exemplified by matching reciprocal connections between inferior olive and cerebellar nuclei. Because the different regions of the cerebellar nuclei show highly specific output patterns, cerebellar modules have been suggested to constitute functional entities. This idea is strengthened by the observation that anatomically defined modules adhere to the distribution of chemical markers in the cerebellar cortex suggesting that modules not only differ in their input and output relations but also may differ in operational capabilities. Here, I will briefly review some recent data on the establishment of cerebellar modules in rats. Furthermore, some evidence will be shown suggesting that the other main afferent system (i.e., mossy fibers), at least to some extent, also adheres to the modular organization. Finally, using retrograde transneuronal tracing with rabies virus, some evidence will be provided that several cerebellar modules may be involved in the control of individual muscles
Cerebellar Zones: A Personal History
Cerebellar zones were there, of course, before anyone noticed them. Their history is that of young people, unhindered by preconceived ideas, who followed up their observations with available or new techniques. In the 1960s of the last century, the circumstances were fortunate because three groups, in Leiden, Lund, and Bristol, using different approaches, stumbled on the same zonal pattern in the cerebellum of the cat. In Leiden, the Häggqvist myelin stain divulged the compartments in the cerebellar white matter that channel the afferent and efferent connections of the zones. In Lund, the spino-olivocerebellar pathways activated from individual spinal funiculi revealed the zonal pattern. In Bristol, charting the axon reflex of olivocerebellar climbing fibers on the surface of the cerebellum resulted in a very similar zonal map. The history of the zones is one of accidents and purposeful pursuit. The technicians, librarians, animal caretakers, students, secretaries, and medical illustrators who made it possible remain unnamed, but their contributions certainly should be acknowledged
The SGLT2 Inhibitor Dapagliflozin Reduces Liver Fat but Does Not Affect Tissue Insulin Sensitivity: A Randomized, Double-Blind, Placebo-Controlled Study With 8-Week Treatment in Type 2 Diabetes Patients
OBJECTIVE The aim of this study was to investigate tissue-specific effects of dapagliflozin on insulin sensitivity and liver and body fat in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS This randomized, double-blind, parallel group, placebo-controlled study recruited 32 patients with type 2 diabetes. Enrolled patients were to have HbA(1c) 6.5-10.5% (48-91 mmol/mol) and >= 3 months of stable treatment with metformin, dipeptidyl peptidase 4 inhibitor, or their combination. Patients were randomized 1:1 to receive 10 mg dapagliflozin or placebo daily for 8 weeks. Before and after the intervention, tissue insulin sensitivity was measured using [F-18]-fluorodeoxyglucose and positron emission tomography during hyperinsulinemic-euglycemic clamp. Liver proton density fat fraction (PDFF) and adipose tissue volumes were assessed using MRI, and blood biomarkers were analyzed. RESULTS After 8 weeks, glycemic control was improved by dapagliflozin (placebo-corrected change in HbA(1c) -0.39%, P < 0.01), but whole-body glucose uptake was not increased (P = 0.90). Tissue-specific insulin-stimulated glucose uptake did not change in skeletal muscle, liver, myocardium, or white and brown adipose tissue, and endogenous glucose production remained unaffected. However, there were significant placebo-corrected decreases in liver PDFF (-3.74%, P < 0.01), liver volume (-0.10 L, P < 0.05), visceral adipose tissue volume (-0.35 L, P < 0.01), interleukin-6 (-1.87 pg/mL, P < 0.05), and N-terminal prohormone of brain natriuretic peptide (-96 ng/L, P = 0.03). CONCLUSIONS In this study, 8 weeks of treatment with dapagliflozin reduced liver PDFF and the volume of visceral adipose tissue in obese patients with type 2 diabetes. Although glycemic control was improved, no effect on tissue-level insulin sensitivity was observed
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