ABSTRACT
Gamma-ray emission from a narrow band at the galactic equator has previously been detected up to 30 GeV. We report evidence for a TeV gamma-ray signal from a region of the galactic plane by Milagro, a large-field-of-view water Cherenkov detector for extensive air showers. An excess with a significance of 4.5 standard deviations has been observed from the region of galactic longitude l E (40 degrees, 100 degrees) and latitude /b/ < 5 degrees. Under the assumption of a simple power law spectrum, with no cutoff in the EGRET-Milagro energy range, the measured integral flux is phi gamma(>3.5 TeV) = (6.4 +/- 1.4 +/- 2.1) x 10(-11) cm(-2) s(-1) sr(-1). This flux is consistent with an extrapolation of the EGRET spectrum between 1 and 30 GeV in this galactic region.
ABSTRACT
Milagrito, a detector sensitive to very high energy gamma rays, monitored the northern sky from 1997 February through 1998 May. With a large field of view and a high duty cycle, this instrument was well suited to perform a search for TeV gamma-ray bursts (GRBs). We report on a search made for TeV counterparts to GRBs observed by BATSE. BATSE detected 54 GRBs within the field of view of Milagrito during this period. An excess of events coincident in time and space with one of these bursts, GRB 970417a, was observed by Milagrito. The excess has a chance probability of 2.8x10-5 of being a fluctuation of the background. The probability for observing an excess at least this large from any of the 54 bursts is 1.5x10-3. No significant correlations were detected from the other bursts.
ABSTRACT
The Robotic Optical Transient Search Experiment (ROTSE) seeks to measure simultaneous and early afterglow optical emission from gamma-ray bursts (GRBs). A search for optical counterparts to six GRBs with localization errors of 1 deg2 or better produced no detections. The earliest limiting sensitivity is mROTSE>13.1 at 10.85 s (5 s exposure) after the gamma-ray rise, and the best limit is mROTSE>16.0 at 62 minutes (897 s exposure). These are the most stringent limits obtained for the GRB optical counterpart brightness in the first hour after the burst. Consideration of the gamma-ray fluence and peak flux for these bursts and for GRB 990123 indicates that there is not a strong positive correlation between optical flux and gamma-ray emission.
ABSTRACT
The Milagrito water Cerenkov detector near Los Alamos, New Mexico, was operated as a sky monitor at energies of a few TeV between 1997 February and 1998 May, including the period of the strong, long-lasting 1997 flare of Markarian 501. Milagrito served as a test run for the full Milagro detector. An event excess with a significance of 3.7 sigma from Markarian 501 was observed, in agreement with expectations.
ABSTRACT
Plasma observations at Jupiter show that the outer regions of the Jovian magnetosphere are remarkably similar to those of Earth. Bow-shock precursor electrons and ions were detected in the upstream solar wind, as at Earth. Plasma changes across the bow shock and properties of the magnetosheath electrons were much like those at Earth, indicating that similar processes are operating. A boundary layer populated by a varying mixture of solar wind and magnetospheric plasmas was found inside the magnetopause, again as at Earth. In the middle magnetosphere, large electron density excursions were detected with a 10-hour periodicity as planetary rotation carried the tilted plasma sheet past Ulysses. Deep in the magnetosphere, Ulysses crossed a region, tentatively described as magnetically connected to the Jovian polar cap on one end and to the interplanetary magnetic field on the other. In the inner magnetosphere and lo torus, where corotation plays a dominant role, measurements could not be made because of extreme background rates from penetrating radiation belt particles.
ABSTRACT
Folic acid oxidase from erythrocytes oxidatively cleaves folic acid at the C-9-N-10 bond to yield pterin-6-aldehyde and p-aminobenzoyl glutamic acid, with the concomitant generation of singlet oxygen. The emission from singlet oxygen is proportional to the enzyme activity. DABCO was used as a singlet oxygen emission enhancer to increase the sensitivity of the measurement. In general, pregnant women show high enzymatic activity, but the emission is strongly quenched by DABCO. This is contrary to normal and cancer cases in which an increase in the emission was observed. This effect is larger in cancer cases. These results are presented as a potential method for detecting physiological and pathological human conditions.
Subject(s)
Erythrocytes/enzymology , Neoplasms/enzymology , Peroxidases/blood , Female , Humans , Luminescent Measurements , Male , PregnancyABSTRACT
A relatively simple procedure for the measurement of urinary chemiluminescence is described and some of the variables affecting such measurements are examined. Normal urinary chemiluminescence is due to lipoperoxidation, presumably through the Haber-Weiss reaction, generating singlet oxygen as emitter. It was found that urinary chemiluminescence was higher in normal smokers than in normal non-smokers and very low in cancer patients. Oral distribution of ascorbic acid reduced urinary chemiluminescence of both normal smokers and non-smokers. Presumably, the spontaneous chemiluminescence in the urine could serve as a cancer marker.
Subject(s)
Neoplasms/diagnosis , Urine/analysis , Clinical Laboratory Techniques , Female , Humans , Lipid Peroxides/urine , Luminescent Measurements , Male , Reference ValuesABSTRACT
Prior to and after removal of the tonsils and adenoids at the ENT clinic in Lucerne, phoniatric and X-ray examinations were performed in 42 children with normal velo-pharyngeal closure. Prior to the operation the velo-pharyngeal closure took place against the adenoid tissue. The surface of contact and the inclinatation of the velum were dependent on the amount of hyperplastic adenoid tissue. The configuration and the mobility of the velum were more important for the post-operative velo-pharyngeal closure than the distance from the pharyngeal wall. 3 months following the operation the velum was reaching the posterior pharyngeal wall. A distinct Passavant ridge was only visible in cases having slight difficulties in the post-operative adaptation of the velo-pharyngeal closure.
