T-wave alternans found in preventricular tachyarrhythmias in CCU patients using a wavelet transform-based methodology

Ventricular tachyarrhythmias are potentially lethal cardiac pathologies and the commonest cause of sudden cardiac death. Efforts to predict the onset of such events are based on feature extraction from the surface ECG. T-wave alternans (TWAs) are considered a marker of abnormal ventricular function that may be associated with ventricular tachycardia (VT) and ventricular fibrillation. A novel TWA detection algorithm utilizing the continuous wavelet transform is described in this paper. Simulated ECGs containing artificial TWA were used to test the algorithm that achieved a sensitivity of 91.40% and a specificity of 94.00%. The algorithm was subsequently used to analyze the ECGs of eight patients prior to the onset of VT. Of these, the algorithm indicated that five patients exhibited TWA prior to the onset of the tachyarrhythmic events, while the remaining three patients did not exhibit identifiable TWA. Healthy individuals were also studied in which one short TWA episode was detected by the algorithm. However, closer visual inspection of the data revealed this to be a likely false positive result.      

The Receptor AT1 Appears to Be Important for the Maintenance of Bone Mass and AT2 Receptor Function in Periodontal Bone Loss Appears to Be Regulated by AT1 Receptor

A large number of experimental studies has demonstrated that angiotensin II (Ang II) is involved in key events of the inflammatory process. This study aimed to evaluate the role of Ang II type 1 (AT1) and Ang II type 2 (AT2) receptors on periodontitis. Methods: Experimental periodontitis was induced by placing a 5.0 nylon thread ligature around the second upper left molar of AT1 mice, no-ligature or ligature (AT1-NL and AT1-L), AT2 (AT2-NL or AT2-L) and wild type (WT-NL or L). Alveolar bone loss was scanned using Micro-CT. Cytokines, peptides and enzymes were analyzed from gingival tissues by Elisa and RT-PCR. Results: The blockade of AT1 receptor resulted in bone loss, even in healthy animals. Ang II receptor blockades did not prevent linear bone loss. Ang II and Ang 1-7 levels were significantly increased in the AT2-L (p < 0.01) group compared to AT2-NL and AT1-L. The genic expression of the Mas receptor was significantly increased in WT-L and AT2-L compared to (WT-NL and AT2-NL, respectively) and in AT1-L. Conclusions: Our data suggest that the receptor AT1 appears to be important for the maintenance of bone mass. AT2 receptor molecular function in periodontitis appears to be regulated by AT1.     

Wavelet Transform Analysis of Open Channel Wake Flows

Wavelet transform analysis offers a new approach to signal processing through its ability to decompose signals in both time and frequency. As such, it is more suited to nonstationary and intermittent signals than traditional Fourier analysis. The first part of this paper provides an introduction to the theory and signal processing properties of both continuous and discrete wavelet transform analysis. An account is then given of the application of wavelet transform analysis to a variety of experimental open channel wake flows. Feature location is undertaken using a continuous wavelet transform, and both turbulent statistical analysis and thresholding of the turbulent signal components are undertaken using a discrete wavelet transform.     

Developmental and individual differences in the use of the control-of-variables strategy.

48 6th and 8th graders were given 2 successive presentations of a standard Piagetian control-of-variables (COV) task. Between the 2 presentations, Ss in 4 conditions took part in an activity designed to elicit the COV strategy or to serve as a control. In a 2nd session, Ss were administered a different task requiring use of the COV strategy, a task requiring use of a different formal operations scheme (proportionality), and a measure of field independence. For older Ss, strategy use increased equally from the 1st to the 2nd presentation in all 4 conditions; for the younger Ss, strategy use increased only for 2 conditions containing a set of intervening probe questions. At both ages, "spontaneous" (i.e., 1st presentation) COV strategy users outperformed their "latent" (2nd presentation only) peers on all 3 Session 2 tasks. Latent strategy users outperformed strategy-absent Ss on the COV transfer task and on the proportionality task. Data clarify the distinction between spontaneous and latent levels of availability of a formal operations strategy. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An AI-based Approach for Improved Sign Language Recognition using Multiple Videos

Multimedia Tools and Applications - People with hearing and speaking disabilities face significant hurdles in communication. The knowledge of sign language can help mitigate these hurdles, but most...     

Sintering Time Dependent Supersolidus Liquid Phase Sintering Behaviour of a Metal Injection Molded Nickel-Base Superalloy

Metallurgical and Materials Transactions A - Supersolidus Liquid Phase Sintering of a high refractory metal Ni-based superalloy revealed that the liquid fraction and associated grain growth...     

AT1 and AT2 Receptor Knockout Changed Osteonectin and Bone Density in Mice in Periodontal Inflammation Experimental Model

Background: The aim of this study was to evaluate the role of AT1 and AT2 receptors in a periodontal inflammation experimental model. Methods: Periodontal inflammation was induced by LPS/Porphyromonas gingivalis. Maxillae, femur, and vertebra were scanned using Micro-CT. Maxillae were analyzed histopathologically, immunohistochemically, and by RT-PCR. Results: The vertebra showed decreased BMD in AT1 H compared with WT H (p < 0.05). The femur showed increased Tb.Sp for AT1 H and AT2 H, p < 0.01 and p < 0.05, respectively. The Tb.N was decreased in the vertebra (WT H-AT1 H: p < 0.05; WT H-AT2 H: p < 0.05) and in the femur (WT H-AT1 H: p < 0.01; WT H-AT2 H: p < 0.05). AT1 PD increased linear bone loss (p < 0.05) and decreased osteoblast cells (p < 0.05). RANKL immunostaining was intense for AT1 PD and WT PD (p < 0.001). OPG was intense in the WT H, WT PD, and AT2 PD when compared to AT1 PD (p < 0.001). AT1 PD showed weak immunostaining for osteocalcin compared with WT H, WT PD, and AT2 PD (p < 0.001). AT1 H showed significantly stronger immunostaining for osteonectin in fibroblasts compared to AT2 H (p < 0.01). Conclusion: AT1 receptor knockout changed bone density, the quality and number of bone trabeculae, decreased the number of osteoblast cells, and increased osteonectin in fibroblasts.     

Halonitromethane formation potentials in drinking waters

Halonitromethanes (HNMs) are highly cyto- and genotoxic nitrogenous disinfection by-products (DBPs) that have been detected in some water distribution systems. In this study, a systematic investigation was conducted to examine the formation potential of HNMs in drinking waters under different oxidation conditions. Formation potential tests of samples obtained from various drinking water sources showed that ozonation-chlorination produced the highest HNM yields followed by in the order of chlorination, ozonation-chloramination, and chloramination. Similar or higher HNM yields were observed in the treated waters (i.e., after conventional water treatment) than in the raw waters, indicating that hydrophilic natural organic matter (NOM) components that are not effectively removed by conventional treatment processes are likely the main precursors of HNMs. This was further confirmed by examining HNM formation potentials of NOM fractions obtained with resin fractionation. Hydrophilic NOM fractions (HPI) showed significantly higher HNM yields than hydrophobic (HPO) and transphilic (TPH) fractions. The correlation analysis of HNM formation potentials during ozonation-chlorination with various water quality parameters showed the best correlation between the HNM yields and the ratio of dissolved organic carbon to dissolved organic nitrogen concentrations in the water samples tested.     

Structural and magnetotransport properties in Co/nonmagnetic films

Four types of thin films were prepared by sequentially depositing ultrathin Co layers and nonmagnetic layers, including an insulator Al₂O₃, a semiconductor ZnO, a semimetal C, and a normal metal Cu on glass substrates. The zero-field-cooled and field-cooled measurements and transmission electron microscopy studies confirmed that the films consist of Co particles dispersed in the matrix. All films show negative magnetoresistance at room temperature except those with C. The films with the ZnO spacer exhibit the largest magnetoresistance, which makes the system a candidate for useful spintronic devices. The magnetic circular dichroism data show that ZnO electrons are partially spin-polarized, which may account for the large magnetoresistance of granular films.     

Abdominal sacral colpoperineopexy: a new approach for correction of posterior compartment defects and perineal descent associated with vaginal vault prolapse

OBJECTIVE: Our purpose was to assess a modification of abdominal sacral colpopexy in 19 patients. STUDY DESIGN: The rectovaginal space was dissected to the superior aspect of the posterior vaginal fascia still contiguous with the perineal body. Mersilene (Ethicon, Somerville, N.J.) mesh was sutured to this fascia and along the entire posterior vaginal wall. Patients with vault prolapse, perineal descent, and associated rectoceles or enteroceles are reported. Outcome measures included bowel symptoms and pelvic organ prolapse staging. Defecography was performed in three patients. Wilcoxon signed rank analysis was used for comparison of prolapse measures. RESULTS: Mean follow-up was 11 weeks. Bowel symptoms improved in 8 of 11 women. No subjects had greater than stage II prolapse postoperatively and median improvement in stage was 3 (range 2 to 4). The mean decrease in the genital hiatus measurement was 3.13 +/- 1.25 (range 2 to 6) cm. Postoperative defecography documented correction of rectoceles and enteroceles and improvement in perineal descent with straining. CONCLUSIONS: Abdominal sacral colpoperineopexy is effective surgery for vaginal vault prolapse associated with perineal descent and posterior vaginal defects.