Tidal dynamics in the Gulf of Maine and New England Shelf : an application of FVCOM

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C12010, doi:10.1029/2011JC007054.The unstructured-grid, Finite-Volume Community Ocean Model (FVCOM) was used to simulate the tides in the Gulf of Maine (GoM) and New England Shelf (NES) for homogeneous and summer stratified conditions. FVCOM captures the near-resonant nature of the semidiurnal tide and energy flux in the GoM and the complex dynamics governing the tide in the NES. Stratification has limited impact on tidal elevation, but can significantly modify the tidal current profile. Internal tides are energetic in the stratified regions over steep bottom topography, but their contribution to the total tidal energy flux is only significant over the northeast flank of Georges Bank. The model suggests that the tidal flushing-induced eddy east of Monomoy Island is the dynamic basis for the locally observed phase lead of the M2 tide. The southward propagating tidal wave east of Cape Cod encounters the northeastward propagating tidal wave from the NES south of Nantucket Island, forming a zone of minimum sea level along a southeast-oriented line from Nantucket Island. These two waves are characterized by linear dynamics in which bottom friction and advection are negligible in the momentum balance, but their superposition leads to a strong nonlinear current interaction and large bottom stress in the zone of lowest sea elevation.This research is supported by the U.S. GLOBEC Northwest Atlantic/Georges Bank Program NSF (OCE-0234545, 0227679, 0606928, 0726851 and 0814505) to Changsheng Chen and Qixchun Xu and NSF grant (OCE-02-27679) and the WHOI Smith Chair to Robert Beardsley and Richard Limeburner. The tidal model-data comparison on Nantucket Sound/Shoals is partially the result of research sponsored by the MIT Sea Grant College Program, under NOAA grant NA06OAR4170019, MIT SG project 2006-R/RC-102, 2006-R/RC-103, 2006-R/RC-102, 2006-R/RC-107, 2008-R/RC-107), 2010-R/RC-116 and the NOAA NERACOOS Program for the UMASS team. C. Chen’s contribution is also supported by Shanghai Ocean University International Cooperation Program (A-2302-11-0003), the Program of Science and Technology Commission of Shanghai Municipality (09320503700), the Leading Academic Discipline Project of Shanghai Municipal Education Commission (project J50702), and Zhi jiang Scholar and 111 project funds of the State Key Laboratory for Estuarine and Coastal Research, East China Normal University (ECNU).2012-06-1

Arginine methylation expands the regulatory mechanisms and extends the genomic landscape under E2F control

E2F is a family of master transcription regulators involved in mediating diverse cell fates. Here, we show that residuespecific arginine methylation (meR) by PRMT5 enables E2F1 to regulate many genes at the level of alternative RNA splicing, rather than through its classical transcription-based mechanism. The p100/TSN tudor domain protein reads the meR mark on chromatin-bound E2F1, allowing snRNA components of the splicing machinery to assemble with E2F1. A large set of RNAs including spliced variants associate with E2F1 by virtue of the methyl mark. By focusing on the deSUMOylase SENP7 gene, which we identified as an E2F target gene, we establish that alternative splicing is functionally important for E2F1 activity. Our results reveal an unexpected consequence of arginine methylation, where reader-writer interplay widens the mechanism of control by E2F1, from transcription factor to regulator of alternative RNA splicing, thereby extending the genomic landscape under E2F1 control

Establishing a rodent stroke perfusion computed tomography model

Brain computed tomography perfusion imaging in acute stroke may help guide therapy. However, the perfusion thresholds defining potentially salvageable (penumbra) and irreversibly injured (infarct core) tissue require further validation. The aim of this study was to validate infarct core and penumbra perfusion thresholds in a rodent stroke model by developing and optimising perfusion computed tomography imaging, performing serial scanning and correlating scans with final histology. Stroke was induced in male Wistar rats (n=17) using the middle cerebral artery thread-occlusion method. Perfusion computed tomography scans were obtained immediately pre- and postocclusion, and every 30 min for 2.5 h. Histological changes of infarction were assessed after 24 h. High-quality maps of cerebral blood flow and cerebral blood volume were generated at multiple coronal planes after optimisation of contrast injection and scanning parameters. The prestroke absolute cerebral blood flow and cerebral blood volume values (mean±SD) were 158.2 ± 49.94 ml/min per 100 g and 5.6 ± 1.13 ml per 100 g, respectively. Cerebral blood flow was significantly lower in the infarct region of interest than the contralateral hemisphere region of interest at all time points, except the 0.5 h postocclusion time point. However, cerebral blood volume was only significantly lower in the infarct region of interest than the contralateral hemisphere region of interest at the 1 h and the 1.5 h time points (postocclusion). This study has demonstrated for the first time the feasibility of performing perfusion computed tomography in the most commonly used animal model of stroke. The model will allow definitive studies to determine optimal thresholds and the reliability of perfusion computed tomography measures for infarct core and penumbra

Arginine methylation expands the regulatory mechanisms and extends the genomic landscape under E2F control

E2F is a family of master transcription regulators involved in mediating diverse cell fates. Here, we show that residuespecific arginine methylation (meR) by PRMT5 enables E2F1 to regulate many genes at the level of alternative RNA splicing, rather than through its classical transcription-based mechanism. The p100/TSN tudor domain protein reads the meR mark on chromatin-bound E2F1, allowing snRNA components of the splicing machinery to assemble with E2F1. A large set of RNAs including spliced variants associate with E2F1 by virtue of the methyl mark. By focusing on the deSUMOylase SENP7 gene, which we identified as an E2F target gene, we establish that alternative splicing is functionally important for E2F1 activity. Our results reveal an unexpected consequence of arginine methylation, where reader-writer interplay widens the mechanism of control by E2F1, from transcription factor to regulator of alternative RNA splicing, thereby extending the genomic landscape under E2F1 control

Professionalizing a cottage industry: KTPs and design group development

This paper is an investigation of the factors that influence the growth of design groups when participating in Knowledge Transfer Partnerships (KTPs). There have been many published case studies which associate KTPs with successful innovation and the economic success of the client (eg Design Council, 2001), yet a systematic literature review of leading design and educational management journals found limited empirical evidence that shed light on the influence of KTPs on design group development