Can a supernova be located by its neutrinos?

A future core-collapse supernova in our Galaxy will be detected by several neutrino detectors around the world. The neutrinos escape from the supernova core over several seconds from the time of collapse, unlike the electromagnetic radiation, emitted from the envelope, which is delayed by a time of order hours. In addition, the electromagnetic radiation can be obscured by dust in the intervening interstellar space. The question therefore arises whether a supernova can be located by its neutrinos alone. The early warning of a supernova and its location might allow greatly improved astronomical observations. The theme of the present work is a careful and realistic assessment of this question, taking into account the statistical significance of the various neutrino signals. Not surprisingly, neutrino-electron forward scattering leads to a good determination of the supernova direction, even in the presence of the large and nearly isotropic background from other reactions. Even with the most pessimistic background assumptions, SuperKamiokande (SK) and the Sudbury Neutrino Observatory (SNO) can restrict the supernova direction to be within circles of radius $5^\circ$ and $20^\circ$, respectively. Other reactions with more events but weaker angular dependence are much less useful for locating the supernova. Finally, there is the oft-discussed possibility of triangulation, i.e., determination of the supernova direction based on an arrival time delay between different detectors. Given the expected statistics we show that, contrary to previous estimates, this technique does not allow a good determination of the supernova direction.Comment: 11 pages including 2 figures. Revised version corrects typos, adds some brief comment

Fluorimetric assay of ergotamine

Studies on the fluorescence properties of ergotamine in water at various pH values, and in several organic solvents are described. An assay procedure for ergotamine, based on its intense fluorescence in ethanol, is presented. Extraction of ergotamine into benzene from basic aqueous solution is followed by transfer of the extract to ethanol for fluorescence determination. The plot of fluorescence intensity vs. concentration is linear up to 5 μg ml-1, and the assay has a limit of detection of 0.002 μg ml-1. Reproducibility data at the 2.5-μg ml-1 level are given

Finding mammals using far-infrared thermal imaging

We examined the utility of far-infrared thermal imaging devices to detect and census mammals in the field. We used a Thermovision 210 to survey individuals, nests, or burrows of red squirrels (Tamiasciurus hudsonicus), arctic ground squirrels (Spermophilus parryii), snowshoe hares (Lepus americanus), and meadow jumping mice (Zapus hudsonius). Using far-infrared thermal imaging, we successfully detected free-ranging red squirrels, snowshoe hares, and meadow jumping mice. Thermal imaging also was highly successful in deter- mining activity at nests or burrows of Arctic ground squirrels. Far-infrared thermal imaging, however, was not useful in detecting active nests of red squirrels. These differences are largely attributable to variation among species in the insulative property of nests or fur. We review some of the limitations of far-infrared thermal imaging and conclude that it may provide a useful tool for certain ecological field studies

Buccal absorption of ergotamine

The rate of disappearance of ergotamine from the mouth after buccal administration has been studied in seven subjects. Allowance has been made for non-absorptive losses of the drug due to experimental technique. The absorption of ergotamine across the buccal mucosa appears to be a passive process, pH-dependent but independent of ergotamine concentration or the simultaneous presence of caffeine. Because of the low solubility of ergotamine at the pH of saliva, it is unlikely that therapeutically useful amounts of the drug would have absorbed across the buccal mucosa even after the drug had been in the mouth for five minutes

The effect of certain drugs on the plasma protein binding of phenytoin

Summary: Most of the phenytoin in plasma is protein bound. Anti‐convulsants are often prescribed in combination and it is important to know if other anticonvulsants displace phenytoin from its plasma‐protein binding sites. If this happened, the biological effect of phenytoin could be altered without much change in its total concentration in plasma. The binding of phenytoin to serum albumin and plasma protein in vitro has been studied by ultrafiltration techniques and equilibrium dialysis at a variety of temperatures and in the presence of “therapeutic” concentrations of other anticonvulsants and aspirin. Equilibrium dialysis and ultrafiltration yielded comparable results. Phenytoin binding de‐creased with increasing temperature (92% bound at 3 °C, 80% bound at 37 °C). With the possible exception of sulthiame, the other anticonvulsants tested (phenobarbitone, ethosuximide, diazepam and carbamazepine), and also aspirin, did not displace phenytoin from its plasma protein binding sites. These findings may be helpful in interpreting plasma phenytoin concentrations when other anticonvulsants are prescribed simultaneously

The renal handling of diphenylhydantoin and 5-(p-hydroxyphenyl)-5-phenylhydantoin

The renal clearances of diphenylhydantoin (DPH) and its major metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin (HPPH) have been measured in groups of 16 and 14 ambulant epileptic patients, respectively. All patients had normal renal function (creatinine clearances, 83 to 148 ml per minute), and were taking oral diphenylhydantoin sodium in doses of 300 to 500 mg per day. DPH clearance (3 to 23 ml per minute, depending on urine flow rate) was considerably less than that expected for inulin, and it seems probable that DPH undergoes net resorption in its passage through the kidney. HPPH clearance (76 to 420 ml per minute depending on urine flow rate) exceeded expected inulin clearance if urine flow rates were sufficiently high, allowing the suggestion that net secretion of HPPH occurs during its passage through the nephron. Although the clearances of both compounds increase with urine flow rate, it is concluded that neither oliguria nor polyuria would be likely to greatly influence plasma DPH concentration in the short term, making dosage adjustment in these two circumstances unnecessary, at least as a matter of urgency

Effects of foraging waterfowl in winter flooded rice fields on weed stress and residue decomposition

This study quantifies the agronomic benefits of foraging waterfowl in winter flooded rice fields in the Sacramento Valley of California (US). Fifteen winter flooded rice fields along a 105 km long transect, each with five pairs of waterfowl exclosures and control plots were used to measure residue decomposition in spring, and weed biomass and grain yield at harvest. Experimental exclusion of waterfowl resulted in a significant increase in remaining residue from 1014 to 1233 kg ha¿1 across the transect. At seven sites with high waterfowl activity, remaining residue increased from 836 to 1549 kg ha¿1 when waterfowl were excluded from the plot. Grassy weed biomass increased from 44 to 91 kg ha¿1 over the whole transect in absence of waterfowl. At seven sites with high waterfowl activity the grassy weed biomass more than doubled in the absence of waterfowl from 89 to 204 kg ha¿1. No significant yield effect could be detected. Winter flooding rice fields resulted in mutual benefits for waterfowl and agriculture that could be of particular significance in organic farming systems

Effects of foraging waterfowl in winter flooded rice fields on weed stress and residue decomposition

This study quantifies the agronomic benefits of foraging waterfowl in winter flooded rice fields in the Sacramento Valley of California (US). Fifteen winter flooded rice fields along a 105 km long transect, each with five pairs of waterfowl exclosures and control plots were used to measure residue decomposition in spring, and weed biomass and grain yield at harvest. Experimental exclusion of waterfowl resulted in a significant increase in remaining residue from 1014 to 1233 kg ha¿1 across the transect. At seven sites with high waterfowl activity, remaining residue increased from 836 to 1549 kg ha¿1 when waterfowl were excluded from the plot. Grassy weed biomass increased from 44 to 91 kg ha¿1 over the whole transect in absence of waterfowl. At seven sites with high waterfowl activity the grassy weed biomass more than doubled in the absence of waterfowl from 89 to 204 kg ha¿1. No significant yield effect could be detected. Winter flooding rice fields resulted in mutual benefits for waterfowl and agriculture that could be of particular significance in organic farming systems