Sigmoid neural transfer function realized by percolation.

An experiment using the phenomenon of percolation has been conducted to demonstrate the implementation of neural functionality (summing and sigmoid transfer). A simple analog approximation to digital percolation is implemented. The device consists of a piece of amorphous silicon with stochastic bit-stream optical inputs, in which a current percolating from one end to the other defines the neuron output, also in the form of a stochastic bit stream.

Seroprevalence of HIV infection among patients with pulmonary tuberculosis in Yaounde-Cameroun.

To determine the seroprevalence of infection with the human immunodeficiency virus (HIV) in pulmonary tuberculosis patients, we conducted an HIV serosurvey in 162 inpatients with pulmonary tuberculosis, in Yaoundé Cameroon. HIV seroprevalence in hospitalized pulmonary tuberculosis patients was found to be 9.9% as compared to the seroprevalence rate of 2.

[Yellow fever epidemic in the extreme North of Cameroon in 1990: first yellow fever virus isolation in Cameroon].

Some two years ago, suspicious cases of yellow fever (YF) were reported in northern Cameroon. A deadly epidemic broke out during the second half of the rainy season (from 15 September to 22 December 1990) with 180 known cases, of which 125 died. The real figures could have been between 5000 and 20,000 cases with between 500 and 1000 deaths.

[Variola or a severe case of varicella? A case of human variola due to monkeypox virus in a child from the Cameroon].

Human monkeypox was suspected on clinical grounds in a seven years old child in Cameroon. The diagnosis was confirmed at the Center for Disease Control (CDC) in Atlanta, USA. This condition is rare.