Carsey Perspectives: New Hampshire's Electricity Future

Over the past decade a number of factors have transformed global and national energy markets. Access to low-cost natural gas has been a significant part of this trend. Nationally, natural gas-fired power generation was expected to have exceeded coal-fired power generation for the first time in 2016,  and in New England about 50 percent of electricity is now generated from natural gas. With natural gas now such a large part of New England's energy mix, there is a concern that the demand for heating and electricity during cold periods will cause spikes in wholesale electricity prices and that demand may be greater than the available pipeline capacity to deliver natural gas. The region's utility industry has proposed the expansion of pipeline capacity to meet this seasonal increase in the demand for natural gas

Carsey Perspectives: New Hampshire\u27s Electricity Future; Cost, Reliability, and Risk

May 2017 update PointLogic Energy, a source for natural gas pipeline flow and capacity in the original report, has recently updated its models for calculating natural gas flow in the Tennessee Gas Pipeline in New England. This model update has resulted in significant changes to their previous estimates. Most importantly, data obtained from PointLogic Energy in December 2016 supported the finding that overall net gas flow in the “Tennessee Gas Pipeline: NY to MA” was from Massachusetts to New York from 2013–2016; their revised models indicate a net flow during the same period from New York to Massachusetts. To be conservative, we have removed analysis of natural gas pipeline flow and capacity from this report that relied on the original data obtained from PointLogic Energy. Instead, we use estimates of natural gas pipeline flow and capacity published in a 2014 ICF International report that was commissioned by ISO New England (Exhibit 2-3, pp. 12)a and information provided by the U.S. Energy Information Administration.b Please click here to read the previous version of this publication. In this perspectives brief, authors Cameron Wake, Matt Magnusson, Christine Foreman, and Fiona Wilson examine the cost of electrical power in New Hampshire and New England, the reliability of the electrical power system in terms of its ability to meet demand, and the risk New Hampshire ratepayers might face from various proposals to secure or increase the supply of electricity. They find evidence that near-term levels of demand and supply pose no threat to grid reliability, that current pipeline capacity is adequate, and that better contracting practices and other “soft-infrastructure” changes combined with the promotion of energy efficiency and renewable energy will have at least as large a return on investment as expanded pipeline capacity, without exposing ratepayers to higher electricity rates stemming from expensive infrastructure investments

Practical randomness amplification and privatisation with implementations on quantum computers

We present an end-to-end and practical randomness amplification and privatisation protocol based on Bell tests. This allows the building of device-independent random number generators which output (near-)perfectly unbiased and private numbers, even if using an uncharacterised quantum device potentially built by an adversary. Our generation rates are linear in the repetition rate of the quantum device and the classical randomness post-processing has quasi-linear complexity - making it efficient on a standard personal laptop. The statistical analysis is also tailored for real-world quantum devices. Our protocol is then showcased on several different quantum computers. Although not purposely built for the task, we show that quantum computers can run faithful Bell tests by adding minimal assumptions. In this semi-device-independent manner, our protocol generates (near-)perfectly unbiased and private random numbers on today's quantum computers.Comment: Important revisions and improvements to v1. inc. new sections, improvements to protocol itself and addition of full technical appendixes. 29+23 pages (15 figures and 2 tables

Hydrological characterisation of Ria de Aveiro, Portugal, in early summer

The hydrological features of Ria de Aveiro, a coastal lagoon on the northwest Atlantic coast of Portugal, were investigated in two sampling surveys carried out between 3/6 and 24/6/97 and between 29/6 and 7/7/97, respectively. There was a significant freshwater inflow into the lagoon during the first survey, especially in the first days, due to the recent rainfalls. Records concerning water level, salinity, temperature and current velocity were performed at several stations located along the four main channels of the lagoon. The type of tide at the mouth was determined and was observed that astronomical tide is the main forcing agent driving water circulation in Ria de Aveiro. The tide at the mouth is semidiurnal and the tidal wave propagation in the lagoon has the characteristics of a damped progressive wave. Typical estuarine longitudinal salinity and temperature gradients connected with the distance to the mouth were identified, whereas vertical and transverse gradients were found unimportant, except in the frontal zone between oceanic and fresh water masses. According to the results, even though Ria de Aveiro should be considered as vertically homogeneous, some channels may reveal characteristics of a partially mixed estuary, depending on the freshwater input.Les caractéristiques hydrologiques de la Ria de Aveiro, lagune côtière située au nord-ouest du Portugal, ont été étudiées au cours de deux campagnes effectuées entre le 3 et le 24 juin 1997 et entre le 29 juin et le 7 juillet 1997. Ces périodes suivent d'importants apports d'eau douce dus à des pluies survenues au début de la première campagne. Le niveau de l'eau, la salinité, la température ainsi que l'intensité et la direction du courant ont été enregistrés en plusieurs stations situées le long des quatre branches principales de la Ria de Aveiro. Les caractéristiques de la marée à l'embouchure de la Ria ont été mises en évidence. La circulation à l'intérieur de la lagune est principalement forcée par la marée astronomique de type semi-diurne. Les ondes de marée résultantes ont la caractéristique d'ondes progressives amorties. À l'exception de la zone frontale entre les eaux océaniques et douces, où il existe une certaine stratification verticale et transversale, les gradients de salinité et de température sont typiquement longitudinaux. Bien que la Ria d'Aveiro puisse être considérée comme étant verticalement homogène, certaines branches ont les caractéristiques d'un estuaire partiellement mélangé, variables avec les apports d'eau douce

Comparison of Mortality Following Hospitalisation for Isolated Head Injury in England and Wales, and Victoria, Australia

BACKGROUND: Traumatic brain injury (TBI) remains a leading cause of death and disability. The National Institute for Health and Clinical Excellence (NICE) guidelines recommend transfer of severe TBI cases to neurosurgical centres, irrespective of the need for neurosurgery. This observational study investigated the risk-adjusted mortality of isolated TBI admissions in England/Wales, and Victoria, Australia, and the impact of neurosurgical centre management on outcomes. METHODS: Isolated TBI admissions (>15 years, July 2005-June 2006) were extracted from the hospital discharge datasets for both jurisdictions. Severe isolated TBI (AIS severity >3) admissions were provided by the Trauma Audit and Research Network (TARN) and Victorian State Trauma Registry (VSTR) for England/Wales, and Victoria, respectively. Multivariable logistic regression was used to compare risk-adjusted mortality between jurisdictions. FINDINGS: Mortality was 12% (749/6256) in England/Wales and 9% (91/1048) in Victoria for isolated TBI admissions. Adjusted odds of death in England/Wales were higher compared to Victoria overall (OR 2.0, 95% CI: 1.6, 2.5), and for cases <65 years (OR 2.36, 95% CI: 1.51, 3.69). For severe TBI, mortality was 23% (133/575) for TARN and 20% (68/346) for VSTR, with 72% of TARN and 86% of VSTR cases managed at a neurosurgical centre. The adjusted mortality odds for severe TBI cases in TARN were higher compared to the VSTR (OR 1.45, 95% CI: 0.96, 2.19), but particularly for cases <65 years (OR 2.04, 95% CI: 1.07, 3.90). Neurosurgical centre management modified the effect overall (OR 1.12, 95% CI: 0.73, 1.74) and for cases <65 years (OR 1.53, 95% CI: 0.77, 3.03). CONCLUSION: The risk-adjusted odds of mortality for all isolated TBI admissions, and severe TBI cases, were higher in England/Wales when compared to Victoria. The lower percentage of cases managed at neurosurgical centres in England and Wales was an explanatory factor, supporting the changes made to the NICE guidelines

The discovery of WASP-151b, WASP-153b, WASP-156b: Insights on giant planet migration and the upper boundary of the Neptunian desert

To investigate the origin of the features discovered in the exoplanet population, the knowledge of exoplanets’ mass and radius with a good precision (≲10%) is essential. To achieve this purpose the discovery of transiting exoplanets around bright stars is of prime interest. In this paper, we report the discovery of three transiting exoplanets by the SuperWASP survey and the SOPHIE spectrograph with mass and radius determined with a precision better than 15%. WASP-151b and WASP-153b are two hot Saturns with masses, radii, densities and equilibrium temperatures of 0.31−0.03+0.04 MJ, 1.13−0.03+0.03 RJ,&nbsp;0.22−0.02+0.03 ρJ and 1290−10+20 K, and 0.39−0.02+0.02 MJ, 1.55−0.08+0.10 RJ,&nbsp;0.11−0.02+0.02 ρJ and 1700−40+40 K, respectively. Their host stars are early G type stars (with mag V ~ 13) and their orbital periods are 4.53 and 3.33 days, respectively. WASP-156b is a super-Neptune orbiting a K type star (mag V = 11.6). It has a mass of 0.128−0.009+0.010 MJ, a radius of 0.51−0.02+0.02 RJ, a density of 1.0−0.1+0.1 ρJ, an equilibrium temperature of&nbsp;970−20+30 K and an orbital period of 3.83 days. The radius of WASP-151b appears to be only slightly inflated, while WASP-153b presents a significant radius anomaly compared to a recently published model. WASP-156b, being one of the few well characterized super-Neptunes, will help to constrain the still debated formation of Neptune size planets and the transition between gas and ice giants. The estimates of the age of these three stars confirms an already observed tendency for some stars to have gyrochronological ages significantly lower than their isochronal ages. We propose that high eccentricity migration could partially explain this behavior for stars hosting a short period planet. Finally, these three planets also lie close to (WASP-151b and WASP-153b) or below (WASP-156b) the upper boundary of the Neptunian desert. Their characteristics support that the ultra-violet irradiation plays an important role in this depletion of planets observed in the exoplanet population

Health State Preference Weights for the Glasgow Outcome Scale Following Traumatic Brain Injury: A Systematic Review and Mapping Study

Background: Valid and relevant estimates of health state preference weights (HSPWs) for Glasgow Outcome Scale (GOS) categories are a key input of economic models evaluating treatments for traumatic brain injury (TBI). Objectives: To characterize existing HSPW estimates, and model the EuroQol five-dimensional questionnaire (EQ-5D) from the GOS, to inform parameterization of future economic models. Methods: A systematic review of HSPWs for GOS categories following TBI was conducted using a highly sensitive search strategy implemented in an extensive range of information sources between 1975 and 2016. A cross-sectional mapping study of GOS health states onto the three-level EQ-5D UK tariff index values was also performed in patients with significant TBI (head region Abbreviated Injury Scale score Z3) from the Victoria State Trauma Registry. A limited dependent variable mixture model was used to estimate the 12-month EQ-5D UK value set as a function of GOS category, age, and other explanatory variables. Results: Six unique HSPWs from five eligible studies were identified. All studies were at high risk of bias with limited applicability. The magnitude of HSPWs differed significantly between studies. Three class mixture models demonstrated excellent goodness of fit to the observed Victoria State Trauma Registry data. GOS category, age at injury, sex, comorbidity, and major extracranial injury all had significant independent effects on mean EQ-5D utility values. Conclusions: The few available HSPWs for GOS categories are challenged by potential biases and restricted generalizability. Mixture models are presented to provide HSPWs for GOS categories consistent with the National Institute for Health and Care Excellence reference cas

Ecological Modeling of the Supraglacial Ecosystem: A Process-based Perspective

Glacier and ice sheet surfaces are important microbe-dominated ecosystems that are changing rapidly due to climate change, with potentially significant impacts. A theoretical framework of the supraglacial (glacier surface) ecosystem is needed to enable its mathematical modeling, a necessary tool for understanding, quantifying and predicting present day and future ecosystem dynamics. Here, we review key biological processes occurring on glacier and ice sheet surfaces and present three frameworks for constructing process-based models of the surface ecosystem, using the largest supraglacial ecosystem on Earth—the Greenland ice sheet surface—as an important example. The models are based on organic carbon transformations, but vary in numerical complexity and in the level of detail of biological processes. This perspective is intended to guide future supraglacial ecosystem model development, field data collection for parameterization and validation purposes, and encourage inter-disciplinary collaboration between modelers and experimentalists