Middle Ear Biomechanics In Chinchilla Model Of Acute Otitis Media

Acute otitis media (AOM) is a rapid onset of infection in the middle ear and the most frequently diagnosed disease in pediatric population. Conductive hearing loss is the most prevalent outcome of AOM because pathological changes in the infected middle reduce mobility of the tympanic membrane (TM). Mechanisms of TM mobility loss associated with AOM are not well understood. We hypothesize that middle ear pressure (MEP), middle ear effusion (MEE), and structural changes of ossicular adhesions and ear soft tissues are the main factors contributing to the loss of TM mobility in AOM ears and their effects vary during the course of the disease. In this dissertation, a chinchilla AOM model was produced by transbullar injection of Haemophilus influenzae. Changes of MEP, MEE, and ossicular adhesions were characterized at day 4 (4D) and day 8 (8D) post inoculation. These time points represent relatively early and later phases of AOM. Microstructural changes of the TM, round window membrane (RWM), and stapedial annular ligament (SAL) in the early and later phases of AOM were investigated by histology. Hearing loss in both AOM phases was evaluated by auditory brainstem response (ABR). TM mobility at the umbo and middle ear energy absorbance (EA) were measured in 4D and 8D AOM ears. In each group, the vibration of the umbo and EA was measured at three experimental stages: unopened, pressure-released, and effusion-removed ears. The effects of MEP and MEE and middle ear structural changes were quantified in each group by comparing the TM mobility or EA at one stage with that of the previous stage. Our findings show that the factors affecting TM mobility change with the disease time course. The MEP was the dominant contributor to reduction of TM mobility in 4D AOM ears, but showed little effect in 8D ears when MEE filled the tympanic cavity. MEE was the primary factor affecting TM mobility loss in 8D ears, but affected the 4D ears only at high frequencies. After the release of MEP and removal of MEE, residual loss of TM mobility was seen mainly at low frequencies in both 4D and 8D ears, and was associated with ossicular adhesions. The effects of MEP and MEE on EA were similar to those on TM mobility. Residual loss of EA seems was more likely associated with mechanical property changes of TM. Our findings demonstrate that MEP, MEE, together with middle ear structural changes, contribute to TM mobility loss in the chinchilla AOM ears. Their effects on TM movement at early and later phases of the disease were quantified. This study provides useful experimental data for understanding the mechanism of conductive hearing loss in AOM

Orphan Nuclear Receptor Nur77 Inhibits Cardiac Hypertrophic Response to Beta-Adrenergic Stimulation.

The orphan nuclear receptor Nur77 plays critical roles in cardiovascular diseases, and its expression is markedly induced in the heart after beta-adrenergic receptor (β-AR) activation. However, the functional significance of Nur77 in β-AR signaling in the heart remains unclear. By using Northern blot, Western blot, and immunofluorescent staining assays, we showed that Nur77 expression was markedly upregulated in cardiomyocytes in response to multiple hypertrophic stimuli, including isoproterenol (ISO), phenylephrine (PE), and endothelin-1 (ET-1). In a time- and dose-dependent manner, ISO increases Nur77 expression in the nuclei of cardiomyocytes. Overexpression of Nur77 markedly inhibited ISO-induced cardiac hypertrophy by inducing nuclear translocation of Nur77 in cardiomyocytes. Furthermore, cardiac overexpression of Nur77 by intramyocardial injection of Ad-Nur77 substantially inhibited cardiac hypertrophy and ameliorated cardiac dysfunction after chronic infusion of ISO in mice. Mechanistically, we demonstrated that Nur77 functionally interacts with NFATc3 and GATA4 and inhibits their transcriptional activities, which are critical for the development of cardiac hypertrophy. These results demonstrate for the first time that Nur77 is a novel negative regulator for the β-AR-induced cardiac hypertrophy through inhibiting the NFATc3 and GATA4 transcriptional pathways. Targeting Nur77 may represent a potentially novel therapeutic strategy for preventing cardiac hypertrophy and heart failure

PVDF-Based Piezoelectric Microphone for Sound Detection Inside the Cochlea: Toward Totally Implantable Cochlear Implants

We report the fabrication and characterization of a prototype polyvinylidene fluoride polymer-based implantable microphone for detecting sound inside gerbil and human cochleae. With the current configuration and amplification, the signal-to-noise ratios were sufficiently high for normally occurring sound pressures and frequencies (ear canal pressures >50–60 dB SPL and 0.1–10 kHz), though 10 to 20 dB poorer than for some hearing aid microphones. These results demonstrate the feasibility of the prototype devices as implantable microphones for the development of totally implantable cochlear implants. For patients, this will improve sound reception by utilizing the outer ear and will improve the use of cochlear implants

Intermittent Deep Tillage on Improving Soil Physical Properties and Crop Performance in an Intensive Cropping System

Soil management practices are important parts of sustainable agriculture. Improving tillage practice is important for alleviating soil degradation and promoting sustainable grain production. A four year field experiment was conducted to examine the effects of deep tillage (DT), incorporated into the minimum tillage (MT), on soil physical properties and crop performance. The field experiments included continuous rotary tillage (RT), continuous DT, and intermittent DT every three years, every two years, and every other year, into RT. The results showed that the introduction of DT into continuous RT reduced the soil bulk density of the 20–30 cm soil layer by 5.6% and reduced nutrient stratification rates by 20–30%, which favored more uniformly distributed soil nutrients in the top soil layer. The root growth for treatments with DT in the deep soil layers (1–1.5 m) was significantly improved, which resulted in a higher soil water depletion. Under deficit irrigation scheduling, the improved root growth and soil water uptake in the deep soil layer improved crop growth and grain production. Overall, a 10.5% increase in yield and 18.3% increase in water productivity were observed when intermittent DT was introduced during the four years. The effects of DT could be maintained for two continuous years. Therefore, it was suggested that after two or three years of RT, DT should be applied to improve soil physical properties and ensure high grain production

Intermittent Deep Tillage on Improving Soil Physical Properties and Crop Performance in an Intensive Cropping System

Soil management practices are important parts of sustainable agriculture. Improving tillage practice is important for alleviating soil degradation and promoting sustainable grain production. A four year field experiment was conducted to examine the effects of deep tillage (DT), incorporated into the minimum tillage (MT), on soil physical properties and crop performance. The field experiments included continuous rotary tillage (RT), continuous DT, and intermittent DT every three years, every two years, and every other year, into RT. The results showed that the introduction of DT into continuous RT reduced the soil bulk density of the 20–30 cm soil layer by 5.6% and reduced nutrient stratification rates by 20–30%, which favored more uniformly distributed soil nutrients in the top soil layer. The root growth for treatments with DT in the deep soil layers (1–1.5 m) was significantly improved, which resulted in a higher soil water depletion. Under deficit irrigation scheduling, the improved root growth and soil water uptake in the deep soil layer improved crop growth and grain production. Overall, a 10.5% increase in yield and 18.3% increase in water productivity were observed when intermittent DT was introduced during the four years. The effects of DT could be maintained for two continuous years. Therefore, it was suggested that after two or three years of RT, DT should be applied to improve soil physical properties and ensure high grain production

An Ecological, Power Lean, Comprehensive Marketing Evaluation System Based on DEMATEL–CRITIC and VIKOR: A Case Study of Power Users in Northeast China

The reduction of carbon emissions in the power industry will play a vital role in global decarbonization. The power industry has three main strategies to achieve this reduction in emissions: to implement lean marketing strategies that effectively target users of power and encourage them to adopt decarbonizing technologies and services; to optimize the efficiency of these users of power; and to improve the efficiency of renewable energy sources. This paper establishes a comprehensive evaluation system of indexed data from power industry customers for the development of lean marketing strategies. This system evaluates indexes derived from customer data on renewable energy sources, carbon emissions, energy efficiency, and customer credit. It adopts the DEMATEL–CRITIC combination weight assignment and VIKOR method for system evaluation and conducts simulation experiments on customer data in a region of Northeastern China to give an example of how this method could be applied in practice to lean marketing. The results show that the evaluation system proposed in this paper can govern the lean marketing decision-making of power sales enterprises

On-site Composting for Biocontainment and Safe Disposal of Infectious Animal Carcasses and Manure in the Event of a Bioterrorism Attack

The purpose of this project is to develop composting methods that can be applied on farms or at other sites to ensure the biocontainment of infected poultry or livestock carcasses and their manure in the event of a bioterrorism attack employing foreign animal disease viruses. The methods developed in this project will be efficient at destroying viruses and degrading carcasses to earth-like material. Methods will also be developed to detect and identify volatile organic compounds contained in off-gases produced during composting. An assessment will then be made of the key chemical categories and specific compounds in the gases released. Studies on the gases released and on the breakdown of animal DNA will aim to determine whether this information could be used to predict the overall safety of the compost for disposal on land. Standards will also be developed to determine virus survival under defined composting conditions.This is an abstract of a poster presented at the CRTI Summer Symposium, 13–15 June 2006, Gatineau, QC.</p

Supp File intracochlear microphone2 - Supplemental material for PVDF-Based Piezoelectric Microphone for Sound Detection Inside the Cochlea: Toward Totally Implantable Cochlear Implants

<p>Supplemental material, Supp File intracochlear microphone2 for PVDF-Based Piezoelectric Microphone for Sound Detection Inside the Cochlea: Toward Totally Implantable Cochlear Implants by Steve Park, Xiying Guan, Youngwan Kim, Francis (Pete) X. Creighton, Eric Wei, Ioannis(John) Kymissis, Hideko Heidi Nakajima and Elizabeth S. Olson in Trends in Hearing</p