Validity of the Crouter 2-Regression Model for Predicting Energy Expenditure: Transitions from Rest to Activity

The Crouter 2-regression model (15) is a new approach for predicting MET values. However, the Crouter 2-regression model may misclassify walking/jogging during transition periods (i.e. during the first and last minute of the activity) due to the high coefficient of variation resulting in an overestimation of MET values. Purpose: The purpose was to examine the Crouter 2-regression model for predicting MET values during transitions from rest to activity and back to rest. It was hypothesized that starting a walking bout partway through a minute will lead to a misclassification, due to the high coefficient of variation, and therefore over-predict MET values. Methods: Thirty participants (age, 28.2 ± 7.7 yrs; BMI, 24.6 ± 3.6 kg.m-2) volunteered to perform 15 minutes of supine rest followed immediately by 8 minutes of each of the following activities: one-on-one basketball, seated rest, over-ground walking, and seated rest. An ActiGraph GT1M was positioned on the right hip and a portable metabolic unit (Cosmed K4b2) was worn during all activities. The participants were randomly assigned to start the activity bouts at 0-s, 20-s or 40-s into the minute (according to the ActiGraph clock). Results: The Crouter 2-regression model under-predicted the total energy cost of basketball compared to the Cosmed K4b2 by an average of 12.8 MET·minutes (P \u3c 0.001) (15.9%). During walking, the Crouter 2-regression model over-predicted MET values compared to the Cosmed K4b2 during the transitional minutes in the 20-s and 40-s conditions by an average of 2.2 METs (P \u3c 0.001). However, it accurately predicted MET values during minutes 2-7 part of the bout. Conclusion: The energy cost of basketball was under-predicted by the Crouter 2-regression model. During the walk-to-rest and rest-to-walk transitions, the Crouter 2-regression model significantly over-predicted the MET values in the 20-s and 40-s conditions. This over-prediction was due to the high coefficient of variation and the oxygen deficit and debt. Despite these limitations, the Crouter 2-regression model still provided a closer estimate of MET values compared to the Cosmed K4b2 for basketball and walking compared to other commonly used single-regression equations for the ActiGraph. Supported by NIH Grant OIR21 CA122430-0

Impulse breakdown delay in liquid dielectrics

Theoretical images of streamers, revealing the mechanisms behind impulse breakdown in liquid dielectrics, are presented. Streamers lead to electrical breakdown by forming paths, capable of carrying large current amplitudes between electrodes. Breakdown delays and terminal currents are calculated for various electrode geometries (40 μm needle and 6.35 mm sphere) and gap distances (up to 10 mm). Modeling results indicate that the breakdown in needle-needle electrodes requires higher impulse voltage amplitudes than in needle-sphere electrodes for the same gap distances. Streamers in needle-sphere geometries are about 50% thicker than streamers propagating in needle-needle geometries under similar impulse voltage amplitudes.ABB Corporate Research Center (Vasteras, Sweden)IEEE Dielectrics and Electrical Insulation Society (Fellowship

Genomes of Gardnerella Strains Reveal an Abundance of Prophages within the Bladder Microbiome

Bacterial surveys of the vaginal and bladder human microbiota have revealed an abundance of many similar bacterial taxa. As the bladder was once thought to be sterile, the complex interactions between microbes within the bladder have yet to be characterized. To initiate this process, we have begun sequencing isolates, including the clinically relevant genus Gardnerella. Herein, we present the genomic sequences of four Gardnerella strains isolated from the bladders of women with symptoms of urgency urinary incontinence; these are the first Gardnerella genomes produced from this niche. Congruent to genomic characterization of Gardnerella isolates from the reproductive tract, isolates from the bladder reveal a large pangenome, as well as evidence of high frequency horizontal gene transfer. Prophage gene sequences were found to be abundant amongst the strains isolated from the bladder, as well as amongst publicly available Gardnerella genomes from the vagina and endometrium, motivating an in depth examination of these sequences. Amongst the 39 Gardnerella strains examined here, there were more than 400 annotated prophage gene sequences that we could cluster into 95 homologous groups; 49 of these groups were unique to a single strain. While many of these prophages exhibited no sequence similarity to any lytic phage genome, estimation of the rate of phage acquisition suggests both vertical and horizontal acquisition. Furthermore, bioinformatic evidence indicates that prophage acquisition is ongoing within both vaginal and bladder Gardnerella populations. The abundance of prophage sequences within the strains examined here suggests that phages could play an important role in the species’ evolutionary history and in its interactions within the complex communities found in the female urinary and reproductive tracts

Carbonyl reductase as a significant predictor of survival and lymph node metastasis in epithelial ovarian cancer

We have recently reported a novel function for carbonyl reductase (CR), namely, its ability to modulate the metastatic potential of malignant mouse cells. Because there are currently no data addressing a similar function for CR in human cancers, the aim of this study was to assess a correlation between survival and metastasis, and CR level in epithelial ovarian cancer. Using anti-CR antibody, immunohistochemical staining was performed on 73 epithelial ovarian cancers, 13 borderline malignant tumours, and 25 benign ovarian tumours for a total of 111 specimens. The combined rate for strongly and weakly positive reactions for CR was 32.0% for benign tumours, 38.5% for borderline malignant tumours, and 61.6% for ovarian cancers. The CR-positive rate was 35.7% (weakly positive alone) for ovarian cancers with retroperitoneal lymph node (RLN) metastasis and 67.8% for those without RLN metastasis (P< 0.05). The 5-year survival rate was 62.7% for the patients with CR-negative cancer and 86.1% for those with CR-positive cancer (P< 0.05). The present results indicate that decreased CR expression in epithelial ovarian cancer is associated with RLN metastasis and poor survival.© 2001 Cancer Research Campaignhttp://www.bjcancer.co

Spatiotemporally resolved imaging of streamer discharges in air generated in a wire-cylinder reactor with (sub)nanosecond voltage pulses

We use (sub)nanosecond high-voltage pulses to generate streamers in atmospheric-pressure air in a wire-cylinder reactor. We study the effect of reactor length, pulse duration, pulse amplitude, pulse polarity, and pulse rise time on the streamer development, specifically on the streamer distribution in the reactor to relate it to plasma-processing results. We use ICCD imaging with a fully automated setup that can image the streamers in the entire corona-plasma reactor. From the images, we calculate streamer lengths and velocities. We also develop a circuit simulation model of the reactor to support the analysis of the streamer development. The results show how the propagation of the high-voltage pulse through the reactor determines the streamer development. As the pulse travels through the reactor, it generates streamers and attenuates and disperses. At the end of the reactor, it reflects and adds to itself. The local voltage on the wire together with the voltage rise time determine the streamer velocities, and the pulse duration the consequent maximal streamer length