CD14 Deficiency Impacts Glucose Homeostasis in Mice through Altered Adrenal Tone

The toll-like receptors comprise one of the most conserved components of the innate immune system, signaling the presence of molecules of microbial origin. It has been proposed that signaling through TLR4, which requires CD14 to recognize bacterial lipopolysaccharide (LPS), may generate low-grade inflammation and thereby affect insulin sensitivity and glucose metabolism. To examine the long-term influence of partial innate immune signaling disruption on glucose homeostasis, we analyzed knockout mice deficient in CD14 backcrossed into the diabetes-prone C57BL6 background at 6 or 12 months of age. CD14-ko mice, fed either normal or high-fat diets, displayed significant glucose intolerance compared to wild type controls. They also displayed elevated norepinephrine urinary excretion and increased adrenal medullary volume, as well as an enhanced norepinephrine secretory response to insulin-induced hypoglycemia. These results point out a previously unappreciated crosstalk between innate immune- and sympathoadrenal- systems, which exerts a major long-term effect on glucose homeostasis

An Estimate of Avian Mortality at Communication Towers in the United States and Canada

Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action

Data-Driven Modulation Filter Design Under Adverse Acoustic Conditions And Using Phonetic And Syllabic Units

Constructing speech feature extraction methods that are robust to many types of corrupting acoustic environments remains a daunting task and it is instructive to investigate which properties of the speech carry the discriminative information for recognition under a variety of conditions. In this paper we describe results for generating RASTA-style modulation filters under a number of acoustic environments. We utilize Linear Discriminant Analysis in a manner previously described by van Vuuren and Hermansky to automatically generate discriminant filters for speech with artificially added background noise and reverberation. We also generate the filters using both phonetic and syllabic classification targets. Trends in the responses of the discriminant filters lend support to feature extraction design decisions employed by RASTA-PLP and Modulation-filtered Spectrogram features. Further, tests with added reverberation corroborate views on the perceptual stability of syllabic rates. 1. INTR..

On Data-Derived Temporal Processing In Speech Feature Extraction

Temporal processing and filtering in speech feature extraction are commonly used to aid in performance and robustness in automatic speech recognition. Among the techniques successfully employed are RASTA filtering, delta calculation, and cepstral mean subtraction. The work here explores the use of temporal filter design using LDA to further enhance performance using a few preprocessing configurations. In addition to RASTA filtering, we apply the filters to modulation-spectral features and cepstra while making sure that the assumptions of LDA are observed. We additionally test the use of filters that have been trained in different reverberation conditions, noting from previous work that the presence of reverberation alters the preferred frequency range of the derived filters. Our tests indicate a consistent advantage in phone classification. Word recognition tests, in contrast, reveal that the LDA filters often do not improve upon the existing filters previously used. They can also be m..