WHO OWNS THE WATER? A CASE STUDY OF EL PASO DEL NORTE

This paper, first, reviews the report filed by the Western Water Policy Review Advisory Commission since it touches on all the major issues associated with water rights and uses in the Upper Rio Grande Basin, defined as that part of the river from the San Luis Valley in Colorado to Fort Quitman, Texas. Second, the paper reviews historical developments over water use and water rights and briefly discusses the major characteristics of El Paso del Norte that do and will have an impact on water supply and consumption. Then the paper reviews the positions of the major stakeholders in the Basin, paying particular attention to their legal arguments. Finally, the paper attempts to describe the possible alternative outcomes of the continuing struggle over water.Water rights--Rio Grande Valley, Water supply--Management --Texas--Lower Rio Grande Valley, Water supply--Management--Mexico--Rio Grande Valley, Resource /Energy Economics and Policy,

Magnetic resonance imaging plaque hemorrhage for risk stratification in carotid artery disease with moderate risk under current medical therapy

Background and Purpose—Magnetic resonance imaging (MRI)–defined carotid plaque hemorrhage (MRIPH) can predict recurrent cerebrovascular ischemic events in severe symptomatic carotid stenosis. It is less clear whether MRIPH can improve risk stratification despite optimized medical secondary prevention in those with moderate risk. Methods—One-hundred fifty-one symptomatic patients with 30% to 99% carotid artery stenosis (median age: 77, 60.5% men) clinically deemed to not benefit from endarterectomy were prospectively recruited to undergo MRI and clinical follow-up (mean, 22 months). The clinical carotid artery risk score could be evaluated in 88 patients. MRIPH+ve was defined as plaque intensity >150% that of adjacent muscle. Survival analyses were performed with recurrent infarction (stroke or diffusion-positive cerebral ischemia) as the main end point. Results—Fifty-five participants showed MRIPH+ve; 47 had low, 36 intermediate, and 5 high carotid artery risk scores. Cox regression showed MRIPH as a strong predictor of future infarction (hazard ratio, 5.2; 95% confidence interval, 1.64–16.34; P=0.005, corrected for degree of stenosis), also in the subgroup with 50% to 69% stenosis (hazard ratio, 4.1; 95% confidence interval, 1–16.8; P=0.049). The absolute risk of future infarction was 31.7% at 3 years in MRIPH+ve versus 1.8% in patients without (P<0.002). MRIPH increased cumulative risk difference of future infarction by 47.1% at 3 years in those with intermediate carotid artery risk score (P=0.004). Conclusions—The study confirms MRIPH to be a powerful risk marker in symptomatic carotid stenosis with added value over current risk scores. For patients undergoing current secondary prevention medication with clinically uncertain benefit from recanalization, that is, those with moderate degree stenosis and intermediate carotid artery risk scores, MRIPH offers additional risk stratification

Limits from the Hubble Space Telescope on a Point Source in SN 1987A

We observed supernova 1987A (SN 1987A) with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) in 1999 September, and again with the Advanced Camera for Surveys (ACS) on the HST in 2003 November. No point source is observed in the remnant. We obtain a limiting flux of F_opt < 1.6 x 10^{-14} ergs/s/cm^2 in the wavelength range 2900-9650 Angstroms for any continuum emitter at the center of the supernova remnant (SNR). It is likely that the SNR contains opaque dust that absorbs UV and optical emission, resulting in an attenuation of ~35% due to dust absorption in the SNR. Taking into account dust absorption in the remnant, we find a limit of L_opt < 8 x 10^{33} ergs/s. We compare this upper bound with empirical evidence from point sources in other supernova remnants, and with theoretical models for possible compact sources. Bright young pulsars such as Kes 75 or the Crab pulsar are excluded by optical and X-ray limits on SN 1987A. Of the young pulsars known to be associated with SNRs, those with ages < 5000 years are all too bright in X-rays to be compatible with the limits on SN 1987A. Examining theoretical models for accretion onto a compact object, we find that spherical accretion onto a neutron star is firmly ruled out, and that spherical accretion onto a black hole is possible only if there is a larger amount of dust absorption in the remnant than predicted. In the case of thin-disk accretion, our flux limit requires a small disk, no larger than 10^{10} cm, with an accretion rate no more than 0.3 times the Eddington accretion rate. Possible ways to hide a surviving compact object include the removal of all surrounding material at early times by a photon-driven wind, a small accretion disk, or very high levels of dust absorption in the remnant.Comment: 40 pages, 5 figures. AAStex. Accepted, ApJ 04/28/200

Remote Ischaemic Conditioning after Stroke Trial (RECAST): a pilot randomised placebo controlled phase II trial in acute ischaemic stroke (ISRCTN 86672015)

Background:Repeated episodes of limb ischaemia and reperfusion (remote ischaemic conditioning, RIC) may improve outcome after acute stroke.Methods:We performed a pilot blinded placebo-controlled trial in patients with acute ischaemic stroke, randomised 1:1 to receive four cycles of RIC within 24 hours of ictus. The primary outcome was tolerability and feasibility. Secondary outcomes included safety, clinical efficacy (day 90), putative biomarkers (pre- and post intervention, day 4) and exploratory haemodynamic measures.Findings:Twenty-six patients (13 RIC, 13 sham) were recruited 15.8 hours (SD 6.2) post onset, age 76·2 years (10.5), blood pressure 159/83mmHg (25/11) and NIHSS 5 [IQR 3.75-9.25]. RIC was well tolerated with 49/52 cycles completed in full. Three patients experienced vascular events in the sham group: two ischaemic strokes and two myocardial infarcts versus none in the RIC group (p=0·076, log-rank test). Compared to sham, there was a significant decrease in day 90 NIHSS in the RIC group, median NIHSS 1 [0.5-5] versus 3 [2-9.5], p=0.04; RIC augmented plasma heat shock protein (HSP) 27 (

Sequence-specific cleavage of RNA by Type II restriction enzymes

The ability of 223 Type II restriction endonucleases to hydrolyze RNA–DNA heteroduplex oligonucleotide substrates was assessed. Despite the significant topological and sequence asymmetry introduced when one strand of a DNA duplex is substituted by RNA we find that six restriction enzymes (AvaII, AvrII, BanI, HaeIII, HinfI and TaqI), exclusively of the Type IIP class that recognize palindromic or interrupted-palindromic DNA sequences, catalyze robust and specific cleavage of both RNA and DNA strands of such a substrate. Time-course analyses indicate that some endonucleases hydrolyze phosphodiester bonds in both strands simultaneously whereas others appear to catalyze sequential reactions in which either the DNA or RNA product accumulates more rapidly. Such strand-specific variation in cleavage susceptibility is both significant (up to orders of magnitude difference) and somewhat sequence dependent, notably in relation to the presence or absence of uracil residues in the RNA strand. Hybridization to DNA oligonucleotides that contain endonuclease recognition sites can be used to achieve targeted hydrolysis of extended RNA substrates produced by in vitro transcription. The ability to ‘restrict’ an RNA–DNA hybrid, albeit with a limited number of restriction endonucleases, provides a method whereby individual RNA molecules can be targeted for site-specific cleavage in vitro