Mechanisms of sensorineural cell damage, death and survival in the cochlea.

The majority of acquired hearing loss, including presbycusis, is caused by irreversible damage to the sensorineural tissues of the cochlea. This article reviews the intracellular mechanisms that contribute to sensorineural damage in the cochlea, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. These data have primarily been generated in hearing loss not directly related to age. However, there is evidence that similar mechanisms operate in presbycusis. Moreover, accumulation of damage from other causes can contribute to age-related hearing loss (ARHL). Potential therapeutic interventions to balance opposing but interconnected cell damage and survival pathways, such as antioxidants, anti-apoptotics, and pro-inflammatory cytokine inhibitors, are also discussed

Graph Theoretical Analysis of Network Centric Operations Using Multi-Layer Models

As the Department of Defense continues its transformations to a network centric force, evaluating DoD\u27s progression towards net-centricity remains a challenge. This research proposes to extend the Network Centric Operation Common Framework Version 2.0 (draft) with the metrics based in graph theory and, specifically addresses, among other metrics, the measurement of a net-centric force\u27s mission effectiveness. The research incorporates the importance of understanding network topology for evaluating an environment for net-centricity and using network characteristics to help commanders assess the effects of network changes on mission effectiveness. The multi-layered model of Network Centric Operations and interlayer mapping are introduced to address the interdependent contributions of people, systems, and processes to the success of net-centric operations. A layered network model was populated with data derived from the 2006 Joint Expeditionary Forces Experiment (JEFX). Both static and dynamic network analyses were performed to characterize the network structures and to demonstrate how the interlayer mapping allows networks changes at one layer affects the networks characteristics of other layers. Thirty four excursions were performed on a three-layer model of JEFX network centric operations and the network characteristics were measured using twelve graph-theoretical metrics

Altered White Matter Structure in Adults Following Early Monocular Enucleation

Visual deprivation from early monocular enucleation (the surgical removal of one eye) results in a number of long-term behavioural and morphological adaptations in the visual, auditory, and multisensory systems. This thesis aims to investigate how the loss of one eye early in life affects structural connectivity within the brain. A combination of diffusion tensor imaging and tractography was used to examine structural differences in 18 tracts throughout the brain of adult participants who had undergone early monocular enucleation compared to binocularly intact controls. We report significant structural changes to white matter in early monocular enucleation participants that extend beyond the primary visual pathway to include interhemispheric, auditory and multisensory tracts, as well as several long association fibres. Overall these results suggest that early monocular enucleation has long-term effects on white matter structure throughout the brain

The Role Of Folate In The Association Between Perinatal Air Pollution Exposure And Birth Outcomes In Lanzhou, China

Background: China’s rapid economic and industrial development over the past few decades has been accompanied by tremendous increases in air pollutant emissions and come at a serious cost to the environment and public health. Recent research has revealed an increased risk of adverse birth outcomes associated with perinatal air pollution exposure. Although the mechanisms by which air pollutants contribute to adverse birth outcomes have not yet been established, folate intake has been shown to counteract several of the hypothesized biological pathways. Hypothesis: Dietary folate intake and folic acid supplementation modify the association between perinatal air pollution exposure (PM10, NO2, SO2) and risk of preterm birth and low birth weight. Methods: A hospital-based cohort study in Lanzhou, China was conducted between 2010-2012. Demographic information and dietary intake during pregnancy were collected during an in-person interview near the time of delivery, and pregnancy outcomes and complications were abstracted from medical records. All 8,969 participants’ air pollutant exposures throughout pregnancy were calculated utilizing daily PM10, NO2, and SO2 levels from local air monitoring stations and inverse-distance weighting based on both residential and work addresses. Unconditional logistic regression modeling was used to examine the association between perinatal air pollution exposure and adverse birth outcomes and the role of folate as a potential effect modifier. Results: Mothers exposed to PM10 and SO2 levels above the Chinese NAAQS were at a higher unadjusted risk of adverse birth outcomes than mothers with exposure levels under the standards. Both folate supplementation and high dietary folate intake during pregnancy were significantly protective against both preterm birth and low birth weight without adjustment. Compared to women with air pollutant exposures below the China NAAQS who took folic acid supplements, mothers who did not supplement and had average PM10 and SO2 exposures during pregnancy above the NAAQS were at the highest risk of preterm birth and low birth weight. Women who supplemented with folic acid and were exposed to pollution above the NAAQS had the next highest observed risk, followed by women whose exposures were below the NAAQS but did not supplement. Similar results were observed for dietary folate intake. Mothers with low dietary folate intake and average PM10 and SO2 exposures above the China NAAQS were at the highest risk of both preterm birth and low birth weight, followed by mothers over the NAAQS with high dietary folate intake, and mothers under the NAAQS with low dietary folate intake. These trends were not observed for NO2. There was no significant interaction between folic acid supplementation or dietary folate intake and any of the air pollutant exposure variables in any of the models. Conclusion: Our findings support the hypothesis that perinatal exposure to PM10 and SO2 increases the risk of low birth weight and preterm birth. The highest observed risks of adverse birth outcomes were among women highly exposed to PM10 and SO2 with low dietary folate intake and who did not take folic acid supplements. These findings have important public health implications, as birth outcomes like birth weight and gestational age may be indicative of health outcomes later in life, and are relevant for future air pollution policies and standards as well as maternal nutrition recommendations

A New Hybrid Framework to Efficiently Model Lines of Sight to Gravitational Lenses

In strong gravitational lens systems, the light bending is usually dominated by one main galaxy, but may be affected by other mass along the line of sight (LOS). Shear and convergence can be used to approximate the contributions from less significant perturbers (e.g. those that are projected far from the lens or have a small mass), but higher order effects need to be included for objects that are closer or more massive. We develop a framework for multiplane lensing that can handle an arbitrary combination of tidal planes treated with shear and convergence and planes treated exactly (i.e., including higher order terms). This framework addresses all of the traditional lensing observables including image positions, fluxes, and time delays to facilitate lens modelling that includes the non-linear effects due to mass along the LOS. It balances accuracy (accounting for higher-order terms when necessary) with efficiency (compressing all other LOS effects into a set of matrices that can be calculated up front and cached for lens modelling). We identify a generalized multiplane mass sheet degeneracy, in which the effective shear and convergence are sums over the lensing planes with specific, redshift-dependent weighting factors.Comment: 13 pages, 2 figure

Optimal Mass Configurations for Lensing High-Redshift Galaxies

We investigate the gravitational lensing properties of lines of sight containing multiple cluster-scale halos, motivated by their ability to lens very high-redshift (z ~ 10) sources into detectability. We control for the total mass along the line of sight, isolating the effects of distributing the mass among multiple halos and of varying the physical properties of the halos. Our results show that multiple-halo lines of sight can increase the magnified source-plane region compared to the single cluster lenses typically targeted for lensing studies, and thus are generally better fields for detecting very high-redshift sources. The configurations that result in optimal lensing cross sections benefit from interactions between the lens potentials of the halos when they overlap somewhat on the sky, creating regions of high magnification in the source plane not present when the halos are considered individually. The effect of these interactions on the lensing cross section can even be comparable to changing the total mass of the lens from 10^15 M_sun to 3x10^15 M_sun. The gain in lensing cross section increases as the mass is split into more halos, provided that the lens potentials are projected close enough to interact with each other. A nonzero projected halo angular separation, equal halo mass ratio, and high projected halo concentration are the best mass configurations, whereas projected halo ellipticity, halo triaxiality, and the relative orientations of the halos are less important. Such high mass, multiple-halo lines of sight exist in the SDSS.Comment: Accepted for publication in ApJ; emulateapj format; 24 pages, 13 figures, 1 table; plots updated to reflect erratu

Dynamic 3D Zverse Models on the Web

ZVerse is a 3D printing company that is responsible for converting 2D objects into 3D objects. This company specializes in generating 3D collegiate products. Whenever a customer orders a 3D model, such as an alumni brick, it is often helpful to allow customers to see what the object looks like before the purchase. Unfortunately, previewing the brick at runtime is quite a challenging task. The purpose of our project is to create a shopping website that models the existing ZVerse company website and incorporates dynamic 3D rendering of the brick model with the user­input text. The project can be divided into two main sections. The first part is the development of the webpage that is built on top of a SQL database. From this web application, the user can purchase a product or a brick model while the admin user can upload one. We have carefully design the database to ensure that it met the specific requirements of our web application. For example, there are fields such as isStandard and isVisible that determines whether the brick should be displayed on the site. We also split the product into various school categories so that the user can easily search for the product within their chosen school. Likewise, we make our application as user ­friendly as possible. On the homepage, we give a short tutorial on how to navigate the website. For the custom brick object, we allows users to insert their text and move the text on top of the brick model. We also let them select various font styles. When a potential customer adds an item to the cart, he or she can easily update the quantity or view the inscription text on the shopping cart page. On the admin page, there are small previews of the model for the admin to view. The admin user also has the ability to edit both the title and price of the item. 2 The second part deals with integrating the brick models onto the webpage. We have to consider the directional lights and positions of the brick in x, y coordinates. The brick models comes in different shapes such as rectangular prism, a cube, or a flat plaque. Following our user­ friendly principal, we also enable the user to rotate and zoom on the object. In addition to the brick models itself, we also implement a text layer that aligns perfectly on top of each object. This text layer is made up of three horizontal lines of characters, based upon the value from the three text boxes on the brick display page. A user can input whatever text he or she likes in the textboxes, and the text will be displayed on the brick surface. This is one of the selling features of the webpage because users can now see the preview of the brick in 3D with the text in real time after the user types. Moving the text proves to be even more difficult as we have to make sure that moving the text does not move the underlying brick layer. Eventually, after numerous attempts, we are able to make the brick movable. Overall, the project is successful in implementing the core functionality. With just a few simple clicks on our website, the user is able to view a highly customized brick with text before purchase. In the future, we plan to employ more user customization to the individual brick model such as incorporating various font sizes for the text, allowing greater movement of the brick model, and a greater variety of products

Joint Strong and Weak Lensing Analysis of the Massive Cluster Field J0850+3604

We present a combined strong and weak lensing analysis of the J085007.6+360428 (J0850) field, which was selected by its high projected concentration of luminous red galaxies and contains the massive cluster Zwicky 1953. Using Subaru/Suprime-Cam $BVR_{c}I_{c}i^{\prime}z^{\prime}$ imaging and MMT/Hectospec spectroscopy, we first perform a weak lensing shear analysis to constrain the mass distribution in this field, including the cluster at $z = 0.3774$ and a smaller foreground halo at $z = 0.2713$. We then add a strong lensing constraint from a multiply-imaged galaxy in the imaging data with a photometric redshift of $z \approx 5.03$. Unlike previous cluster-scale lens analyses, our technique accounts for the full three-dimensional mass structure in the beam, including galaxies along the line of sight. In contrast with past cluster analyses that use only lensed image positions as constraints, we use the full surface brightness distribution of the images. This method predicts that the source galaxy crosses a lensing caustic such that one image is a highly-magnified "fold arc", which could be used to probe the source galaxy's structure at ultra-high spatial resolution ($< 30$ pc). We calculate the mass of the primary cluster to be $\mathrm{M_{vir}} = 2.93_{-0.65}^{+0.71} \times 10^{15}~\mathrm{M_{\odot}}$ with a concentration of $\mathrm{c_{vir}} = 3.46_{-0.59}^{+0.70}$, consistent with the mass-concentration relation of massive clusters at a similar redshift. The large mass of this cluster makes J0850 an excellent field for leveraging lensing magnification to search for high-redshift galaxies, competitive with and complementary to that of well-studied clusters such as the HST Frontier Fields.Comment: Accepted for publication in The Astrophysical Journal; 14 pages, 13 figures, 3 table