3,514 research outputs found

    Externalities revisited: the use of an environmental equity account

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    This exploratory paper attempts to restart a debate about the incorporation of environmental externalities into the cost structure of the organisation. A number approaches are considered; regulation together with all that would follow such as audit and policing; pollution permits, which probably can only be used with a sinking lid application; and other charging mechanisms such as making the private sector pay for public sector capital funding. The fourth alternative, the use of an environmental equity account, has not been widely considered in the literature. The paper proposes the use of an environmental equity account (after Boone and Rubenstein, 1997) with the express intent of generating a charge for environmental impact based on the cost of control. That is, the cost of implementing state of the art technology compared to that currently in use within the organisation, is used as a balance which may be either paid as a capital sum or carried as a balance sheet entry upon which dividend payments would have to be made. It is envisaged that both capital sums and dividend payments would go to an agency responsible for environmental remediation activity

    Targeting colorectal cancer with anti-epidermal growth factor receptor antibodies: focus on panitumumab

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    The tumor biology targeted therapies have improved outcomes in colorectal cancer (CRC). The epidermal growth factor receptor (EGFR) inhibitors represent one of these successful strategies. EGFR is frequently overexpressed in CRCs and associated with a malignant phenotype. Two EGFR inhibitors have shown efficacy in metastatic CRC, cetuximab and panitumumab. Cetuximab is a human–mouse chimeric monoclonal antibody that binds to the extracellular domain of the EGF-receptor. Similarly, panitumumab is a fully humanized monoclonal IgG2 antibody, directed against EGFR. Being fully humanized, panitumumab does not contain mouse protein reducing the risk of hypersensitivity. In a pivotal clinical trial, panitumumab was well tolerated and effective, demonstrating an objective response rate of 10% vs best supportive care (ORR = 0%; P < 0.0001). Panitumumab was approved for the treatment of mCRC by the FDA in 2006. Studies combining panitumumab with cytotoxic chemotherapy and other targeted therapies have been completed while others are ongoing to further evaluate the clinical utility of this agent. Recently it has been demonstrated that mutations in KRAS predict the efficacy of panitumumab and cetuximab, limiting their use to CRC patients with wild-type KRAS, and moving the clinical field towards personalized cancer care

    A Slowly Precessing Disk in the Nucleus of M31 as the Feeding Mechanism for a Central Starburst

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    We present a kinematic study of the nuclear stellar disk in M31 at infrared wavelengths using high spatial resolution integral field spectroscopy. The spatial resolution achieved, FWHM = 0."12 (0.45 pc at the distance of M31), has only previously been equaled in spectroscopic studies by space-based long-slit observations. Using adaptive optics-corrected integral field spectroscopy from the OSIRIS instrument at the W. M. Keck Observatory, we map the line-of-sight kinematics over the entire old stellar eccentric disk orbiting the supermassive black hole (SMBH) at a distance of r<4 pc. The peak velocity dispersion is 381+/-55 km/s , offset by 0.13 +/- 0.03 from the SMBH, consistent with previous high-resolution long-slit observations. There is a lack of near-infrared (NIR) emission at the position of the SMBH and young nuclear cluster, suggesting a spatial separation between the young and old stellar populations within the nucleus. We compare the observed kinematics with dynamical models from Peiris & Tremaine (2003). The best-fit disk orientation to the NIR flux is [θl\theta_l, θi\theta_i, θa\theta_a] = [-33 +/- 4∘^{\circ}, 44 +/- 2∘^{\circ}, -15 +/- 15∘^{\circ}], which is tilted with respect to both the larger-scale galactic disk and the best-fit orientation derived from optical observations. The precession rate of the old disk is ΩP\Omega_P = 0.0 +/- 3.9 km/s/pc, lower than the majority of previous observations. This slow precession rate suggests that stellar winds from the disk will collide and shock, driving rapid gas inflows and fueling an episodic central starburst as suggested in Chang et al. (2007).Comment: accepted by Ap

    Maximum black-hole spin from quasi-circular binary mergers

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    Black holes of mass M must have a spin angular momentum S below the Kerr limit chi = S/M^2 < 1, but whether astrophysical black holes can attain this limiting spin depends on their accretion history. Gas accretion from a thin disk limits the black-hole spin to chi_gas < 0.9980 +- 0.0002, as electromagnetic radiation from this disk with retrograde angular momentum is preferentially absorbed by the black hole. Extrapolation of numerical-relativity simulations of equal-mass binary black-hole mergers to maximum initial spins suggests these mergers yield a maximum spin chi_eq < 0.95. Here we show that for smaller mass ratios q = m/M << 1, the superradiant extraction of angular momentum from the larger black hole imposes a fundamental limit chi_lim < 0.9979 +- 0.0001 on the final black-hole spin even in the test-particle limit q -> 0 of binary black-hole mergers. The nearly equal values of chi_gas and chi_lim imply that measurement of supermassive black-hole spins cannot distinguish a black hole built by gas accretion from one assembled by the gravitational inspiral of a disk of compact stellar remnants. We also show how superradiant scattering alters the mass and spin predicted by models derived from extrapolating test-particle mergers to finite mass ratios.Comment: final version accepted in PRD, new Fig.4 and discussio

    Spectral and Spin Measurement of Two Small and Fast-Rotating Near-Earth Asteroids

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    In May 2012 two asteroids made near-miss "grazing" passes at distances of a few Earth-radii: 2012 KP24 passed at nine Earth-radii and 2012 KT42 at only three Earth-radii. The latter passed inside the orbital distance of geosynchronous satellites. From spectral and imaging measurements using NASA's 3-m Infrared Telescope Facility (IRTF), we deduce taxonomic, rotational, and physical properties. Their spectral characteristics are somewhat atypical among near-Earth asteroids: C-complex for 2012 KP24 and B-type for 2012 KT42, from which we interpret the albedos of both asteroids to be between 0.10 and 0.15 and effective diameters of 20+-2 and 6+-1 meters, respectively. Among B-type asteroids, the spectrum of 2012 KT42 is most similar to 3200 Phaethon and 4015 Wilson-Harrington. Not only are these among the smallest asteroids spectrally measured, we also find they are among the fastest-spinning: 2012 KP24 completes a rotation in 2.5008+-0.0006 minutes and 2012 KT42 rotates in 3.634+-0.001 minutes.Comment: 4 pages, 3 figures, accepted for publication in Icaru

    Only connect: addressing the emotional needs of Scotland's children and young people

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    A report on the SNAP (Scottish Needs Assessment Programme) Child and Adolescent Mental Health Phase Two survey. It describes a survey of a wide range of professionals working with children and young people in Scotland, and deals with professional perspectives on emotional, behavioural and psychological problems. Conclusions and recommendations are presented

    Comparison of opioid prescribing by dentists in the United States and England

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    Importance: The United States consumes most of the opioids worldwide despite representing a small portion of the world\u27s population. Dentists are one of the most frequent US prescribers of opioids despite data suggesting that nonopioid analgesics are similarly effective for oral pain. While oral health and dentist use are generally similar between the United States and England, it is unclear how opioid prescribing by dentists varies between the 2 countries. Objective: To compare opioid prescribing by dentists in the United States and England. Design, Setting, and Participants: Cross-sectional study of prescriptions for opioids dispensed from outpatient pharmacies and health care settings between January 1 and December 31, 2016, by dentists in the United States and England. Data were analyzed from October 2018 to January 2019. Exposures: Opioids prescribed by dentists. Main Outcomes and Measures: Proportion and prescribing rates of opioid prescriptions. Results: In 2016, the proportion of prescriptions written by US dentists that were for opioids was 37 times greater than the proportion written by English dentists. In all, 22.3% of US dental prescriptions were opioids (11.4 million prescriptions) compared with 0.6% of English dental prescriptions (28 082 prescriptions) (difference, 21.7%; 95% CI, 13.8%-32.1%; P \u3c .001). Dentists in the United States also had a higher number of opioid prescriptions per 1000 population (35.4 per 1000 US population [95% CI, 25.2-48.7 per 1000 population] vs 0.5 per 1000 England population [95% CI, 0.03-3.7 per 1000 population]) and number of opioid prescriptions per dentist (58.2 prescriptions per dentist [95% CI, 44.9-75.0 prescriptions per dentist] vs 1.2 prescriptions per dentist [95% CI, 0.2-5.6 prescriptions per dentist]). While the codeine derivative dihydrocodeine was the sole opioid prescribed by English dentists, US dentists prescribed a range of opioids containing hydrocodone (62.3%), codeine (23.2%), oxycodone (9.1%), and tramadol (4.8%). Dentists in the United States also prescribed long-acting opioids (0.06% of opioids prescribed by US dentists [6425 prescriptions]). Long-acting opioids were not prescribed by English dentists. Conclusions and Relevance: This study found that in 2016, dentists in the United States prescribed opioids with significantly greater frequency than their English counterparts. Opioids with a high potential for abuse, such as oxycodone, were frequently prescribed by US dentists but not prescribed in England. These results illustrate how 1 source of opioids differs substantially in the United States vs England. To reduce dental opioid prescribing in the United States, dentists could adopt measures similar to those used in England, including national guidelines for treating dental pain that emphasize prescribing opioids conservatively
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