The author researched the following ten languages during his stay in Cameroun from September, 1990 up to February, 1991: Kaka, Makaa, Eton, Ewondo, Bulu, Bafia, Yambasa, Bassa, Douala, Dschang. Generally speaking, their linguistic features can be stated as below: 1) Some of these languages have implosive stops and some have double-articulated stops such as kp and gb. 2) Some of them have seven vowels (i, e, ε, a, _??_, o, u) and others have a central vowel (_??_) besides them. Some have nasalized vowels. 3) Many of them have closed syllables as well as open syllables. 4) Some of them have a phenomenon such that a high-toned syllable becomes middle-toned when it stands immediately after a high-toned syllable. 5) Some languages have very few noun classes. 6) For modification, some languages use a construction made of an adjectival noun followed by ‘of’+a concrete noun. 7) The infinitive prefixes in many languages are not those originating in *ku. 8) Some languages use personal pronouns in some cases instead of original subject prefixes. 9) The object prefixes are not used in many of them. 10) Some languages use verb stems seemingly extended by *ag (+ *a) as well as those with the ending *a. 11) The verbs are tonally divided into two groups in all of them. Their mutual linguistic differences seem to be very large and almost all of them seem to have changed very much from Proto-Bantu although they are spoken near the so-called Bantu homeland.
As a new approach to discovering physiologically active natural compounds, possible medicinal plants used by wild chimpanzees have been studied. Physiological and biological activity tests of three such plants, Vernonia amygdalina, Aspilia mossambicensis, and Ficus exasperata, indicated that they contain a variety of active compounds. Particularly, the activities of V. amygdalina were remarkable, and hence further chemical studies were conducted. In the search for compounds of biological and physiological significance, in particular the bitter principles were investigated. Four known sesquiterpene lactones, vernodalin (1), vernolide (2), hydroxyvernolide (3) and vernodalol (4) were identified, and their anti-tumor and anti-bacterial activities were found. Furthermore, three bitter steroid glucosides and a related non-bitter glucoside, vernonioside A1 (5), A2 (6), A3 (7) and B1 (8) were isolated as new compounds. The significance of the use of V. amygdalina by chimpanzees for the control of parasite related disease and avenues for future research on this topic are discussed.
An eruption began on September 20, 1991, at 1:30 a.m. (LT) from a fissure with the strike of N30°E at about 15km NE from the summit caldera of Nyamuragira after two years and a month's dormancy. A swarm of earthquakes for three days preceded the eruption by one week. The swarm activity gradually declined up to the eruption with changing the waveform of seismogram as lower frequency content. The beginning time of the eruption was clearly recognized by the appearence of continuous tremor on seismograph at BLG station located at 40km south from the eruption site. Lava fountain activity was continuing at the northern end of fissure and produced new cone and two lava flows. The new cone grew up 60-70m high with basal dimension of 400m×300m during a week. The lava flow extended about 6-7km in a NE direction along and over the old 1958, 1967 and 1980 lava flows. This activity was still vigorous on September 30 when we were compeled to leave from this region by a riot in Zaire. The new cone was called Mikombe (meant many bats). Total volume ejected by this eruption will reach the same order of previous ones judging from the out put rate for the first week. We can, therefore, conclude that this eruption lies on the continuation of the recent high active stage of this volcano which has begun from 1976 eruption. After that seven flank eruptions including new one took place on this volcano during 15 years. This occurrence frequency is 2-3 times higher than the previous period from 1900 to 1976.
We have studied on endemic diseases mainly in Kenya. This report contains seven research subjects. 1) Geopathology in western Kenya: during the period 1979-1986, 4, 342 cases out of 25, 343 cases of surgical pathology specimens were diagnosed as malignant neoplasm. Incidence of each disease was as follows: uterus cancer (21%), skin cancer (15%), malignant lymphoma (15%), soft tissue tumor (7%), tumor with unknown primary site (5%), esophageal carcinoma (4%), tumor unclassified (3%), eye tumor (3%), breast cancer (3%), liver cancer (3%), and ovarian carcinoma (2%). Kaposi's sarcoma, Burkitt's lymphoma, fibrosarcoma, penile cancer, and retinoblastoma showed a characteristic feature of ethnical and geographical distribution. 2) Kaposi's sarcoma is classified into at least four forms; classical, endemic, epidemic, and posttransplantation forms. Endemic Kaposi's sarcoma in Africa manifested long clinical duration, nodular cutaneous appearance, and granulomatous and fibrosarcomatous histological findings which were quite different from other three forms. 3) Hemangioma of granulation tissue type showing histologically atypical capillary proliferation of the upper respiratory tract of Kenyan patients were studied. 4) Epstein-Barr virus and tumor: comparative pathological study between Burkitt's lymphoma in African children and nasopharyngeal carcinoma of adult patients in southern China is in progress. 5) Seroepidemiology of Hepatitis B surface antigen (HBsAg) revealed that Kenya is one of the most prevalent areas of Hepatitis B Virus in the world. 6) Liver diseases in the tropics: parenchymal regenerative change was prominent in chronic viral hepatitis, while parenchymal necrosis and degeneration of the liver were characteristic in toxemia of pregnancy, yellow fever, and aflatoxicosis. 7) Postmortems in Kenya: more than 80% of autopsy cases in Kenya were non-cancer diseases. On the contrary, 70% of autopsy cases in Japan (Akita Prefecture) were cancer diseases. These results suggest that environmental factors and human ecology exert and influence upon endemic disease manifestations. (Research Permit, Republic of Kenya: No. OP. 13/001/8c224/12)