Comparison of Transmittance and Reflectance Pulse Oximetry in Anesthetized Dogs

Objectives: The tongue is the standard site for placement of a pulse oximeter probe but is difficult to access during certain procedures such as dental and ophthalmic procedures and computerized tomography of the head. The aim of this study was to evaluate the performance of a new-generation reflectance pulse oximeter using the tail and tibia as sites for probe attachment.Materials and Methods: A total of 100 client-owned dogs that underwent anesthesia for various reasons were premedicated with butorphanol (n = 50; 0.2 mg/kg; group BUT) or butorphanol and dexmedetomidine (n = 50; 5 μg/kg; group DEX), administered intravenously. Anesthesia was induced with propofol and maintained with sevoflurane. A transmittance pulse oximeter probe was placed on the tongue and served as the reference standard. A reflectance probe was randomly placed on the tail base or the proximal tibia, and the position changed after testing. Signals from three consecutive measurements were obtained at each position. Failure was defined as “no signal,” “low signal,” or a pulse difference >10/min compared with the ECG heart rate. Data were analyzed using chi-square test, Wilcoxon matched-pair signed-rank test, and Bland-Altman analysis. P < 0.05 was considered significant.Results: In both groups (BUT and DEX), failure rate was higher when the tibia and tail were used as probe sites compared with the tongue. In both groups, the failure rate was higher for the tibia than for the tail. Dexmedetomidine-induced vasoconstriction increased failure rate at all probe positions.Clinical Significance: The tail base, but not the tibia, is an acceptable position for reflectance pulse oximeter probes in dogs. The tongue remains the probe site of choice, if accessible.

MethylToSNP: identifying SNPs in Illumina DNA methylation array data

Background Current array-based methods for the measurement of DNA methylation rely on the process of sodium bisulfite conversion to differentiate between methylated and unmethylated cytosine bases in DNA. In the absence of genotype data this process can lead to ambiguity in data interpretation when a sample has polymorphisms at a methylation probe site. A common way to minimize this problem is to exclude such potentially problematic sites, with some methods removing as much as 60% of array probes from consideration before data analysis. Results Here, we present an algorithm implemented in an R Bioconductor package, MethylToSNP, which detects a characteristic data pattern to infer sites likely to be confounded by polymorphisms. Additionally, the tool provides a stringent reliability score to allow thresholding on SNP predictions. We calibrated parameters and thresholds used by the algorithm on simulated and real methylation data sets. We illustrate findings using methylation data from YRI (Yoruba in Ibadan, Nigeria), CEPH (European descent) and KhoeSan (southern African) populations. Our polymorphism predictions made using MethylToSNP have been validated through SNP databases and bisulfite and genomic sequencing. Conclusions The benefits of this method are threefold. First, it prevents extensive data loss by considering only SNPs specific to the individuals in the study. Second, it offers the possibility to identify new polymorphisms in samples for which there is little known about the genetic landscape. Third, it identifies variants as they exist in functional regions of a genome, such as in CTCF (transcriptional repressor) sites and enhancers, that may be common alleles or personal mutations with potential to deleteriously affect genomic regulatory activities. We demonstrate that MethylToSNP is applicable to the Illumina 450K and Illumina 850K EPIC array data and is also backwards compatible to the 27K methylation arrays. Going forward, this kind of nuanced approach can increase the amount of information derived from precious data sets by considering samples of the project individually to enable more informed decisions about data cleaning.

A universal calibration function for determination of soil moisture with cosmic-ray neutrons

A cosmic-ray soil moisture probe is usually calibrated locally using soil samples collected within its support volume. But such calibration may be difficult or impractical, for example when soil contains stones, in presence of bedrock outcrops, in urban environments, or when the probe is used as a rover. Here we use the neutron transport code MCNPx with observed soil chemistries and pore water distribution to derive a universal calibration function to be used in such environments. Comparisons with independent soil moisture measurements at one cosmic-ray probe site and, separately, at thirty-five sites, show that the universal calibration function explains more than 75% of the total variation within each dataset, permitting accurate isolation of the soil moisture signal from the measured neutron signal.

Healing through ICT: Enhancing wellbeing in an Aboriginal community

Many Aboriginal Australians report a diminished sense of wellbeing in their everyday activities due to racism and separation from their traditional lands and culture. Our research sought to discover whether access and use of culturally appropriate Information and Communication Technology's (ICTs), could have an ameliorative benefit, enhancing participants’ sense of support and engagement with their culture. While multiple studies have shown that access and use of ICTs can provide real benefits in regards to empowerment, few studies have focused specifically on the well-being aspects. The research in this project was a Participatory Action Research (PAR) study with women and girls of the Gugu Badhun (an Aboriginal Australian language group) to explore ways to better support their familial and cultural activities associated with identity and group sustainability. The research was divided into three action-research cycles: group interviews and focus groups, use of a technology probe, and feedback from the participants. The technology probe was a web-based application with access limited to the women in the study. Use of the probe enabled the participants to mentally revisit scenes that had been highly significant to them and to reframe these incidents in ways that enhanced their feelings of wellbeing. The probe site allowed the women a platform to discuss concepts intrinsic to their lives, and how these ideas interlink and enmesh with each other, such as the importance of connection to country, and offline activities surrounding identity and sustainability as a group thereby enhancing their wellbeing.

Dynamics of Membrane Rafts, Talin, and Actin at Nascent and Mechanically Perturbed Focal Adhesions

A single endothelial cell was deformed at the apical surface by binding a functionalized nanoelectrode probe to a predetermined location on the surface of the cell. After identifying the point of contact, as recognized by the electronic signature of the nanoelectrode, and allowing binding to the cell of the fibronectin-functionalized tip, a focal adhesion site was induced at the probe site. The probe was displaced thereby applying a prescribed shear deformation to the surface of the cell. Locations of membrane rafts were identified by cholera toxin, and focal adhesion proteins were assessed using RFP-talin, and GFP-actin. Mechanical coupling and kinetics of assembly of these labeled proteins were measured using time-lapse fluorescent images taken under 60X with a multi-point confocal scanner. Raft marker GM1, Actin, and Talin were observed to sequentially accumulate at probe site with different kinetics not only upon probe contact but also upon deformation. Following deformation, later transient motion of rafts in the opposite direction of initial deformation was observed suggesting that rafts recoil. In conclusion, we report a novel nanoelectrode-based method for controlled manipulation of the cell surface and observed mechanical coupling of focal adhesions and cross-linked lipid rafts.

Impurity Centers in Oxides Investigated by γ-γ Perturbed Angular Correlation Spectroscopy and Ab Initio Calculations

In this chapter Perturbed Angular Correlation (PAC) experiments on binary oxides are described. These experiments provide local-scale fingerprints about the formation, identification, and lattice environment of defect complexes at the PAC probe site. The potential of the PAC observations in conjunction with ab initio calculations is shown. Measurements of the electric-field gradient at impurity sites using111Cd and181Ta probes are reviewed. Special attention is paid to oxides with the bixbyite structure. The case of In2O3is particularly analyzed. Results obtained with HfO2, in form of coarse grain or nano particles, are described. The potential results that can be obtained from Density Functional Theory ab initio calculations in doped systems are shown describing the main results observed in many impurity-host systems.