Narrative of an expedition to explore the river Zaire, usually called the Congo in South Africa, in 1816 /

Mode of access: Internet.

Comparative handbook of Congo languages; being a comparative grammar of the eight principal languages spoken along the banks of the Congo river from the west coast of Africa to Stanley Falls, a distance of 1300 miles, and of Swahili, the "lingua franca" of the country stretching thence to the east coast, with a comparative vocabulary giving 800 selected words from these languages, with their English equivalents, followed by appendices on six other dialects;

Mode of access: Internet.

Global compilation of benthic data sets I

Approaches to quantify the organic carbon accumulation on a global scale generally do not consider the small-scale variability of sedimentary and oceanographic boundary conditions along continental margins. In this study, we present a new approach to regionalize the total organic carbon (TOC) content in surface sediments (<5 cm sediment depth). It is based on a compilation of more than 5500 single measurements from various sources. Global TOC distribution was determined by the application of a combined qualitative and quantitative-geostatistical method. Overall, 33 benthic TOC-based provinces were defined and used to process the global distribution pattern of the TOC content in surface sediments in a 1°x1° grid resolution. Regional dependencies of data points within each single province are expressed by modeled semi-variograms. Measured and estimated TOC values show good correlation, emphasizing the reasonable applicability of the method. The accumulation of organic carbon in marine surface sediments is a key parameter in the control of mineralization processes and the material exchange between the sediment and the ocean water. Our approach will help to improve global budgets of nutrient and carbon cycles.

Organic carbon accumulation in the South Atlantic Ocean

A compilation of 1118 surface sediment samples from the South Atlantic was used to map modern seafloor distribution of organic carbon content in this ocean basin. Using new data on Holocene sedimentation rates, we estimated the annual organic carbon accumulation in the pelagic realm (>3000 m water depth) to be approximately 1.8*10**12 g C/year. In the sediments underlying the divergence zone in the Eastern Equatorial Atlantic (EEA), only small amounts of organic carbon accumulate in spite of the high surface water productivity observed in that area. This implies that in the Eastern Equatorial Atlantic, organic carbon accumulation is strongly reduced by efficient degradation of organic matter prior to its burial. During the Last Glacial Maximum (LGM), accumulation of organic carbon was higher than during the mid-Holocene along the continental margins of Africa and South America (Brazil) as well as in the equatorial region. In the Eastern Equatorial Atlantic in particular, large relative differences between LGM and mid-Holocene accumulation rates are found. This is probably to a great extent due to better preservation of organic matter related to changes in bottom water circulation and not just a result of strongly enhanced export productivity during the glacial period. On average, a two- to three-fold increase in organic carbon accumulation during the LGM compared to mid-Holocene conditions can be deduced from our cores. However, for the deep-sea sediments this cannot be solely attributed to a glacial productivity increase, as changes in South Atlantic deep-water circulation seem to result in better organic carbon preservation during the LGM.

G. bulloides dissolution index of surface sediments

The Atlantic is regarded as a huge carbonate depocenter due to an on average deep calcite lysocline. However, calculations and models that attribute the calcite lysocline to the critical undersaturation depth (hydrographic or chemical lysocline) and not to the depth at which significant calcium carbonate dissolution is observed (sedimentary calcite lysocline) strongly overestimate the preservation potential of calcareous deep-sea sediments. Significant calcium carbonate dissolution is expected to begin firstly below 5000 m in the deep Guinea and Angola Basin and below 4400 m in the Cape Basin. Our study that is based on different calcium carbonate dissolution stages of the planktic foraminifera Globigerina bulloides clearly shows that it starts between 400 and 1600 m shallower depending on the different hydrographic settings of the South Atlantic Ocean. In particular, coastal areas are severely affected by increased supply of organic matter and the resultant production of metabolic CO2 which seems to create microenvironments favorable for dissolution of calcite well above the hydrographic lysocline.

Clay mineralogy of South Atlantic surface sediments

Surface samples, mostly from abyssal sediments of the South Atlantic, from parts of the equatorial Atlantic, and of the Antarctic Ocean, were investigated for clay content and clay mineral composition. Maps of relative clay mineral content were compiled, which improve previous maps by showing more details, especially at high latitudes. Large-scale relations regarding the origin and transport paths of detrital clay are revealed. High smectite concentrations are observed in abyssal regions, primarily derived from southernmost South America and from minor sources in Southwest Africa. Near submarine volcanoes of the Antarctic Ocean (South Sandwich, Bouvet Island) smectite contents exhibit distinct maxima, which is ascribed to the weathering of altered basalts and volcanic glasses. The illite distribution can be subdivided into five major zones including two maxima revealing both South African and Antarctic sources. A particularly high amount of Mg- and Fe-rich illites are observed close to East Antarctica. They are derived from biotite-bearing crystalline rocks and transported to the west by the East Antarctic Coastal Current. Chiorite and well-crystallized dioctaedral illite are typical minerals enriched within the Subantarctic and Polarfrontal-Zone but of minor importance off East Antarctica. Kaolinite dominates the clay mineral assemblage at low latitudes, where the continental source rocks (West Africa, Brazil) are mainly affected by intensive chemical weathering. Surprisingly, a slight increase of kaolinite is observed in the Enderby Basin and near the Filchner-Ronne Ice shelf. The investigated area can be subdivided into ten, large-scale clay facies zones with characteristic possible source regions and transport paths. Clay mineral assemblages of the largest part of the South Atlantic, especially of the western basins are dominated by chlorite and illite derived from the Antarctic Peninsula and southernmost South America and supported by advection within the Circumantarctic Deep Water flow. In contrast, the East Antarctic provinces are relatively small. Assemblages of the eastern basins north of 30°S are strongly influenced by African sources, controlled by weathering regimes on land and by a complex interaction of wind, river and deep ocean transport. The strong gradient in clay mineral composition at the Brazilian slope indicate a relatively low contribution of tropically derived assemblages to the western basins.

Phenotypic Characterization According to The Feather Color of Indigenous Muscovy Ducks Bred in The Back Yard in Brazzaville, The Congo

Abstract.  In Congo, waterfowl genetic resources are constituted by native population of Muscovy ducks that play an important role in food security. The present study aimed to identify and to characterize strains bred in the back yard in the households in Brazzaville. A sample of 154 households drawn over seven districts of Brazzaville was enrolled in the survey. Adults ducks found in the households were identified, pictured by a key of determination and then compared by using the multi resolution analysis image method. The survey recorded 13 strains in which four were considered as newly since they have never been reported elsewhere. These strains received temporally the name of the districts where they have been identified for the first time Makelékélé 1 (0.34%, n=6), Makélékélé 2 (0.11%, n =2), Poto poto 1  (0.28%, n=5) and in Poto poto 2 (0.11%, n=2). Finally, the survey reported nine classical  strains such as  black plumage, duclair, white, tortora, sepia, chocolate, lavender, grey and canizie. The apparent wide variation in plumage colors is an indication that the duck populations have not been ‘purified’ through selective breeding. In the context of the valorization of poultry biodiversity, this work represents a step toward a better knowledge of the production abilities of local ducks breeds in Congo. Key words: Muscovy ducks, color feather, strains, Congo. Abstrak.  Sumber daya genetik unggas air di Kongo mencakup populasi itik lokal yang memegang peranan penting dalam ketahanan pangan. Penelitian ini bertujuan mengidentifikasi dan menggolongkan jenis itik yang dipelihara di pekarangan rumah di Brazzaville. Sampel penelitian menggunakan 154 responden rumah tangga yang tersebar di 7 wilayah Brazzaville. Itik dewasa diidentifikasi dari pekarangan, dan dibandingkan dengan metode Analisis Multi Resolusi. Survey mencatat 13 jenis peranakan, 4 diantaranya dianggap baru karena belum pernah dilaporkan di studi manapun. Jenis ini sementara dinamai sesuai distrik tempatnya pertama ditemukan, yaitu Makelékélé 1 (0,34%, n=6), Makélékélé 2 (0,11%, n =2), Poto poto 1  (0,28%, n=5) dan di Poto poto 2 (0,11%, n=2). Berdasarkan survei didapatkan sembilan jenis klasik yaitu bulu hitam, duclair, putih, tortora, sepia, coklat, lavender, abu-abu dan canizie. Banyaknya ragam warna bulu adalah indikasi bahwa populasi itik belum “dimurnikan” melalui seleksi. Dalam konteks penetapan nilai keanekaragaman hayati unggas, penelitian ini mewakili sebuah langkah menuju pengetahuan yang mendalam akan kemampuan produksi itik yang berkembang di Kongo. Kata kunci: itik Muscovy, warna bulu, strain, Kongo