Great Bay Nitrogen Non-Point Source Study

The Great Bay Estuary is 21 square miles of tidal waters located in southeastern New Hampshire. It is one of 28 “estuaries of national significance” established under the Environmental Protection Agency’s National Estuary Program. The estuary is experiencing the signs of eutrophication, specifically, low dissolved oxygen, macroalgae blooms, and declining eelgrass habitat (DES, 2012). Sixty-eight percent of the nitrogen that ends up in the Great Bay Estuary originates from sources spread across the watershed; the remainder derives from direct discharges of municipal wastewater treatment facilities (DES, 2010; PREP, 2013). In this report, these sources of nitrogen are called non-point sources and consist of atmospheric deposition, fertilizers, human waste disposed into septic systems, and animal waste. The purpose of this study is to determine how much nitrogen each non-point source type contributes to the estuary. The nitrogen loads from municipal wastewater treatment facilities have been reported elsewhere (DES, 2010; PREP, 2012; PREP, 2013) and, therefore, are not included in this study except to provide context. The intended use of this study is for planning purposes, and is not meant for regulatory allocations or specific reduction requirements. The results of the model may be useful for towns or watershed groups for prioritizing nitrogen reduction efforts or as a starting point for more detailed studies of non-point sources. However, more detailed inventories of non-point sources will be needed to track the effects of nitrogen reduction efforts in smaller areas. In addition, the model makes no conclusions about the benefits of nitrogen reductions to receiving waters or overall estuarine health

HexPak and GradPak: variable-pitch dual-head IFUs for the WIYN 3.5m Telescope Bench Spectrograph

We describe the design, construction, and expected performance of two new fiber integral field units (IFUs) --- HexPak and GradPak --- for the WIYN 3.5m Telescope Nasmyth focus and Bench Spectrograph. These are the first IFUs to provide formatted fiber integral field spectroscopy with simultaneous sampling of varying angular scales. HexPak and GradPak are in a single cable with a dual-head design, permitting easy switching between the two different IFU heads on the telescope without changing the spectrograph feed: the two heads feed a variable-width double-slit. Each IFU head is comprised of a fixed arrangement of fibers with a range of fiber diameters. The layout and diameters of the fibers within each array are scientifically-driven for observations of galaxies: HexPak is designed to observe face-on spiral or spheroidal galaxies while GradPak is optimized for edge-on studies of galaxy disks. HexPak is a hexagonal array of 2.9 arcsec fibers subtending a 40.9 arcsec diameter, with a high-resolution circular core of 0.94 arcsec fibers subtending 6 arcsec diameter. GradPak is a 39 by 55 arcsec rectangular array with rows of fibers of increasing diameter from angular scales of 1.9 arcsec to 5.6 arcsec across the array. The variable pitch of these IFU heads allows for adequate sampling of light profile gradients while maintaining the photon limit at different scales.Comment: 10 pages, 4 figures, presented at SPIE, Astronomical Telescopes and Instrumentation, 1 - 6 July 2012, Amsterdam, Netherland

Gating-by-tilt of mechanosensitive membrane channels

We propose an alternative mechanism for the gating of biological membrane channels in response to membrane tension that involves a change in the slope of the membrane near the channel. Under biological membrane tensions we show that the energy difference between the closed (tilted) and open (untilted) states can far exceed kBT and is comparable to what is available under simple ilational gating. Recent experiments demonstrate that membrane leaflet asymmetries (spontaneous curvature) can strong effect the gating of some channels. Such a phenomenon would be more easy to explain under gating-by-tilt, given its novel intrinsic sensitivity to such asymmetry.Comment: 10 pages, 2 figure

High-resolution Near-Infrared Images and Models of the Circumstellar Disk in HH 30

We present Hubble Space Telescope (HST) Near-Infrared Camera and Multi-object Spectrometer (NICMOS) observations of the reflection nebulosity associated with the T Tauri star HH 30. The images show the scattered light pattern characteristic of a highly inclined, optically thick disk with a prominent dustlane whose width decreases with increasing wavelength. The reflected nebulosity exhibits a lateral asymmetry in the upper lobe on the opposite side to that reported in previously published Wide Field Planetary Camera 2 (WFPC2) images. The radiation transfer model which most closely reproduces the data has a flared accretion disk with dust grains larger than standard interstellar medium grains by a factor of approximately 2.1. A single hotspot on the stellar surface provides the necessary asymmetry to fit the images and is consistent with previous modeling of the light curve and images. Photometric analysis results in an estimated extinction of Av>~80; however, since the photometry measures only scattered light rather than direct stellar flux, this a lower limit. The radiative transfer models require an extinction of Av = 7,900.Comment: Accepted for publication in Ap.

Patterns of Drug Use and Serum Sodium Concentrations in Older Hospitalized Patients : A Latent Class Analysis Approach

Peer reviewedPublisher PD

Artificial mirtron-mediated gene knockdown:Functional DMPK silencing in mammalian cells

Mirtrons are introns that form pre-miRNA hairpins after splicing to produce RNA interference (RNAi) effectors distinct from Drosha-dependent intronic miRNAs. Here we present a design algorithm for artificial mirtrons and demonstrate, for the first time, efficient gene knockdown of myotonic dystrophy protein kinase (DMPK) target sequences in Renilla luciferase 3' UTR and subsequently pathogenic DMPK mRNA, causative of Type I myotonic dystrophy, using artificial mirtrons cloned as eGFP introns. Deep sequencing of artificial mirtrons suggests that functional mature transcripts corresponding to the designed sequence were produced in high abundance. They were further shown to be splicing-dependent, Drosha-independent, and partially dependent on exportin-5, resulting in the precise generation of pre-miRNAs. In a murine myoblast line containing a pathogenic copy of human DMPK with more than 500 CUG repeats, the DMPK artificial mirtron corrected DM1-associated splicing abnormalities of the Serca-1 mRNA, demonstrating the therapeutic potential of mirtron-mediated RNAi. Thus, further development and exploitation of the unique properties of mirtrons will benefit future research and therapeutic RNAi applications as an alternative to conventional RNAi strategies

Constituting monetary conservatives via the 'savings habit': New Labour and the British housing market bubble

The ongoing world credit crunch might well kill off the most recent bubble dynamics in the British housing market by driving prices systematically downwards from their 2007 peak. Nonetheless, the experience of that bubble still warrants analytical attention. The Labour Government might not have been responsible for consciously creating it, but it has certainly grasped the opportunities the bubble has provided in an attempt to enforce a process of agential change at the heart of the British economy. The key issue in this respect is the way in which the Government has challenged the legitimacy of passive welfare receipts in favour of establishing a welfare system based on incorporating the individual into an active asset-holding society. The housing market has taken on new political significance as a means for individuals first to acquire assets and then to accumulate wealth on the back of asset ownership. The ensuing integration of the housing market into an increasingly reconfigured welfare system has permeated into the politics of everyday life. It has been consistent with individuals remaking their political subjectivities in line with preferences for the type of conservative monetary policies that typically keep house price bubbles inflated

Therapeutic strategies for spinal muscular atrophy: SMN and beyond

Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder characterized by loss of motor neurons and muscle atrophy, generally presenting in childhood. SMA is caused by low levels of the survival motor neuron protein (SMN) due to inactivating mutations in the encoding gene SMN1 A second duplicated gene, SMN2, produces very little but sufficient functional protein for survival. Therapeutic strategies to increase SMN are in clinical trials, and the first SMN2-directed antisense oligonucleotide (ASO) therapy has recently been licensed. However, several factors suggest that complementary strategies may be needed for the long-term maintenance of neuromuscular and other functions in SMA patients. Pre-clinical SMA models demonstrate that the requirement for SMN protein is highest when the structural connections of the neuromuscular system are being established, from late fetal life throughout infancy. Augmenting SMN may not address the slow neurodegenerative process underlying progressive functional decline beyond childhood in less severe types of SMA. Furthermore, individuals receiving SMN-based treatments may be vulnerable to delayed symptoms if rescue of the neuromuscular system is incomplete. Finally, a large number of older patients living with SMA do not fulfill the present criteria for inclusion in gene therapy and ASO clinical trials, and may not benefit from SMN-inducing treatments. Therefore, a comprehensive whole-lifespan approach to SMA therapy is required that includes both SMN-dependent and SMN-independent strategies that treat the CNS and periphery. Here, we review the range of non-SMN pathways implicated in SMA pathophysiology and discuss how various model systems can serve as valuable tools for SMA drug discovery