Energetic solar particle fluxes out to 3 AU during the 7 May 1978 flare event

Simultaneous solar proton flux measurements on IMP 7 and by the world wide neutron monitor network during the May 7, 1978 flare event led to conclusions that in the energy range from 50 MeV to 10 GeV: (1) the propagation of the flare particles in the interplanetary magnetic field (IMF) between the Sun and the Earth was nearly scatter free; and (2) therefore, the intensity time (IT) profiles of the solar proton fluxes observed at Earth for about one hour after onset represent the solar injection profiles even to energies as low as 50 MeV. Observations of the IMF at Helios A indicate that the IMF was undisturbed between the Sun and Helios A at the time of the May 7, 1978 flare event; and, therefore, the solar particle propagation was also scatter free from the Sun to Helios A

Brunnian links are determined by their complements

If L_1 and L_2 are two Brunnian links with all pairwise linking numbers 0, then we show that L_1 and L_2 are equivalent if and only if they have homeomorphic complements. In particular, this holds for all Brunnian links with at least three components. If L_1 is a Brunnian link with all pairwise linking numbers 0, and the complement of L_2 is homeomorphic to the complement of L_1, then we show that L_2 may be obtained from L_1 by a sequence of twists around unknotted components. Finally, we show that for any positive integer n, an algorithm for detecting an n-component unlink leads immediately to an algorithm for detecting an unlink of any number of components. This algorithmic generalization is conceptually simple, but probably computationally impractical.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol1/agt-1-7.abs.htm

Extended γ‐ray emission in solar flares

During the solar flare events on 11 and 15 June 1991, COMPTEL measured extended emission in the neutron capture line for about 5 hours after the impulsive phase. The time profiles can be described by a double exponential decay with decay constants on the order of 10 min for the fast and 200 min for the slow component. Within the statistical uncertainty both flares show the same long‐term behaviour. The spectrum during the extended phase is significantly harder than during the impulsive phase and pions are not produced in significant numbers before the beginning of the extended emission. Our results with the measurements of others allow us to rule out long‐term trapping of particles in non‐turbulent loops to explain the extended emission of these two flares and our data favour models based on continued acceleration

Some characteristics of the solar flare event of February 16, 1984

In the morning of February 16, 1984 a solar cosmic ray event (GLE) was recorded by the world wide network of neutron monitors (NM). The counting rate vs. time profile of the Goose Bay NM (geog. lat. = 53.3 deg. N, deog. long. = 299.6 deg E) where the increase is expressed as percent of the counting rate of an equatorial sea level NM is presented. The Goose Bay NM was observed to have the maximum response to the solar particles. Its counting rate vs. time profile exhibits a rapid increase to maximum, has a large amplitude (approx. 170%) and decays rapidly to background in approx. 90 min. In Fig. 1 we also show the counting rate vs. time profile for the Tixie Bay NM (71.6 deg, 128.9 deg) which recorded an increase of only a few percent. Since the NMs at Goose Bay and Tixie Bay have asymptotic viewing directions approx. 180 deg apart in longitude, the anisotropy of the solar particle flux at Earth from these stations

Between the Devil and the cross:Religion, slavery, and the making of the Anlo-Ewe

The idea that mission Christianity played a pivotal role in the creation of modern African ethnic identities has become paradigmatic. Yet, the actual cultural and social processes that facilitated the widespread reception of specific ethnic identities have been under-researched. Suggesting that historians have overemphasised the role of Christian schooling and theology in ethnic identity formation, this article examines how the Anlo people of south-eastern Ghana came, over the twentieth century, to recognise themselves as part of the larger Ewe ethnic group. Although Christian missionaries were the first to conceive of 'Ewe' as a broad ethnic identity, a corpus of non-Christian ritual practices pioneered by inland Ewe slave women were crucial to many Anlos' embrace of Eweness

Epidemiology and Clinical Significance of Nontuberculous Mycobacteria in Patients Negative for Human Immunodeficiency Virus in Switzerland

Over the last decades, the rate of isolation of tubercle bacilli has declined in the developed countries, while the incidence of infection with nontuberculous mycobacteria (NTM) has increased. In a retrospective study, we analyzed all cases of patients negative for human immunodeficiency virus (HIV) and from whom NTM were isolated in the Zurich area of Switzerland from 1983 to 1988. During the 6-year study period, 513 patients infected with NTM were identified, 34 of whom had clinically significant disease. The presentation of mycobacteriosis was found to be lung disease in 23 cases, soft-tissue disease in 10 cases, and disseminated disease in one case. The highest attack rate of pulmonary mycobacteriosis was 0.49% and was found in the group of patients 41-50 years old. During the 6-year period, the incidence of tuberculosis declined from 16.2 to 13.2 per 100,000 population, while the incidence of mycobacteriosis increased from 0.4 to 0.9 per 100,000 population. Clinically nonsignificant NTM isolates were found more frequently in patients with chronic lung diseases (P < .01) and especially in patients with a history of tuberculosis (P < .001

X- and gamma-ray observations of the 15 November 1991 Solar Flare

This work expands the current understanding of the 15 November 1991 Solar Flare. The flare was a well observed event in radio to gamma-rays and is the first flare to be extensively studied with the benefit of detailed soft and hard X-ray images. In this work, we add data from all four instruments on the Compton Gamma Ray Observatory. Using these data we determined that the accelerated electron spectrum above 170 keV is best fit with a power law with a spectral index of −4.6, while the accelerated proton spectrum above 0.6 MeV is fit with a power law of spectral index −4.5. From this we computed lower limits for the energy content of these particles of∼1023 ergs (electrons) and ∼1027 ergs (ions above 0.6 MeV). These particles do not have enough energy to produce the white-light emission observed from this event. We computed a time constant of 26+20−15 s for the 2.223 MeV neutron capture line, which is consistent at the 2σ level with the lowest values of ∼70 s found for other flares. The mechanism for this short capture time may be better understood after analyses of high energy EGRET data that show potential evidence for pion emission near ∼100 MeV

COMPTEL gamma ray and neutron measurements of solar flares

COMPTEL on the Compton Gamma Ray Observatory has measured the flux of x‐rays and neutrons from several solar flares. These data have also been used to image the Sun in both forms of radiation. Unusually intense flares occurred during June 1991 yielding data sets that offer some new insight into of how energetic protons and electrons are accelerated and behave in the solar environment. We summarize here some of the essential features in the solar flare data as obtained by COMPTEL during June 1991

COMPTEL solar flare observations

COMPTEL as part of a solar target of opportunity campaign observed the sun during the period of high solar activity from 7-15 Jun. 1991. Major flares were observed on 9 and 11 Jun. Although both flares were large GOES events (greater than or = X10), they were not extraordinary in terms of gamma-ray emission. Only the decay phase of the 15 Jun. flare was observed by COMPTEL. We report the preliminary analysis of data from these flares, including the first spectroscopic measurement of solar flare neutrons. The deuterium formation line at 2.223 MeV was present in both events and for at least the 9 Jun. event, was comparable to the flux in the nuclear line region of 4-8 MeV, consistent with Solar-Maximum Mission (SSM) Observations. A clear neutron signal was present in the flare of 9 Jun. with the spectrum extending up to 80 MeV and consistent in time with the emission of gamma-rays, confirming the utility of COMPTEL in measuring the solar neutron flux at low energies. The neutron flux below 100 MeV appears to be lower than that of the 3 Jun. 1982 flare by more than an order of magnitude. The neutron signal of the 11 Jun. event is under study. Severe dead time effects resulting from the intense thermal x-rays require significant corrections to the measured flux which increase the magnitude of the associated systematic uncertainties