Low density of top predators (seabirds and marine mammals) in the high Arctic pack ice

The at-sea distribution of top predators, seabirds and marine mammals, was determined in the high Arctic pack ice on board the icebreaker RV Polarstern in July to September 2014. In total, 1,620 transect counts were realised, lasting 30 min each. The five most numerous seabird species represented 74% of the total of 15,150 individuals registered: kittiwake Rissa tridactyla, fulmar Fulmarus glacialis, puffin Fratercula arctica, Ross’s gull Rhodostethia rosea, and little auk Alle alle. Eight cetacean species were tallied for a total of 330 individuals, mainly white-beaked dolphin Lagenorhynchus albirostris and fin whale Balaenoptera physalus. Five pinniped species were represented by a total of 55 individuals and the polar bear Ursus maritimus was represented by 12 individuals. Four main geographical zones were identified: from Tromsø to the outer marginal ice zone (OMIZ), the Arctic pack ice (close pack ice, CPI), the end of Lomonosov Ridge off Siberia, and the route off Siberia and northern Norway. Important differences were detected between zones, both in species composition and in individual abundance. Low numbers of species and high proportion of individuals for some of them can be considered to reflect very low biodiversity. Numbers encountered in zones 2 to 4 were very low in comparison with other European Arctic seas. The observed differences showed strong patterns

Inferring the Demographic History of African Farmers and Pygmy Hunter–Gatherers Using a Multilocus Resequencing Data Set

The transition from hunting and gathering to farming involved a major cultural innovation that has spread rapidly over most of the globe in the last ten millennia. In sub-Saharan Africa, hunter–gatherers have begun to shift toward an agriculture-based lifestyle over the last 5,000 years. Only a few populations still base their mode of subsistence on hunting and gathering. The Pygmies are considered to be the largest group of mobile hunter–gatherers of Africa. They dwell in equatorial rainforests and are characterized by their short mean stature. However, little is known about the chronology of the demographic events—size changes, population splits, and gene flow—ultimately giving rise to contemporary Pygmy (Western and Eastern) groups and neighboring agricultural populations. We studied the branching history of Pygmy hunter–gatherers and agricultural populations from Africa and estimated separation times and gene flow between these populations. We resequenced 24 independent noncoding regions across the genome, corresponding to a total of ∼33 kb per individual, in 236 samples from seven Pygmy and five agricultural populations dispersed over the African continent. We used simulation-based inference to identify the historical model best fitting our data. The model identified included the early divergence of the ancestors of Pygmy hunter–gatherers and farming populations ∼60,000 years ago, followed by a split of the Pygmies' ancestors into the Western and Eastern Pygmy groups ∼20,000 years ago. Our findings increase knowledge of the history of the peopling of the African continent in a region lacking archaeological data. An appreciation of the demographic and adaptive history of African populations with different modes of subsistence should improve our understanding of the influence of human lifestyles on genome diversity

Comparative analysis of co-processed starches prepared by three different methods

Co-processing is currently of interest in the generation of high-functionality excipients for tablet formulation. In the present study, comparative analysis of the powder and tableting properties of three co-processed starches prepared by three different methods was carried out. The co-processed excipients consisting of maize starch (90%), acacia gum (7.5%) and colloidal silicon dioxide (2.5%) were prepared by co-dispersion (SAS-CD), co-fusion (SAS-CF) and co-granulation (SAS-CG). Powder properties of each co-processed excipient were characterized by measuring particle size, flow indices, particle density, dilution potential and lubricant sensitivity ratio. Heckel and Walker models were used to evaluate the compaction behaviour of the three co-processed starches. Tablets were produced with paracetamol as the model drug by direct compression on an eccentric Tablet Press fitted with 12 mm flat-faced punches and compressed at 216 MPa. The tablets were stored at room temperature for 24 h prior to evaluation. The results revealed that co-granulated co-processed excipient (SAS-CG) gave relatively better properties in terms of flow, compressibility, dilution potential, deformation, disintegration, crushing strength and friability. This study has shown that the method of co-processing influences the powder and tableting properties of the co-processed excipient

Comparative analysis of co-processed starches prepared by three different methods

Co-processing is currently of interest in the generation of high-functionality excipients for tablet formulation. In the present study, comparative analysis of the powder and tableting properties of three co-processed starches prepared by three different methods was carried out. The co-processed excipients consisting of maize starch (90%), acacia gum (7.5%) and colloidal silicon dioxide (2.5%) were prepared by co-dispersion (SAS-CD), co-fusion (SAS-CF) and co-granulation (SAS-CG). Powder properties of each co-processed excipient were characterized by measuring particle size, flow indices, particle density, dilution potential and lubricant sensitivity ratio. Heckel and Walker models were used to evaluate the compaction behaviour of the three co-processed starches. Tablets were produced with paracetamol as the model drug by direct compression on an eccentric Tablet Press fitted with 12 mm flat-faced punches and compressed at 216 MPa. The tablets were stored at room temperature for 24 h prior to evaluation. The results revealed that co-granulated co-processed excipient (SAS-CG) gave relatively better properties in terms of flow, compressibility, dilution potential, deformation, disintegration, crushing strength and friability. This study has shown that the method of co-processing influences the powder and tableting properties of the co-processed excipient

Summer social structure of crabeater seal <i>Lobodon carcinophaga</i> in the Amundsen Sea, Antarctica

During the PS75 expedition of ice-breaking RV Polarstern in the Amundsen Sea, in February–March 2010, we studied the at-sea quantitative distribution of the “upper trophic levels,” seabirds and marine mammals. In the Amundsen Sea Embayment, 14,200 pinnipeds belonging to four species were recorded (2100 during 670 half-hour transect counts from the bridge and 12,100 during 50 h of helicopter flight). Crabeater seal Lobodon carcinophaga represented more than 97 % of the total. Two types of major aggregations of crabeaters were noted: on the one hand, very large groups hauled out on the pack ice, composed mainly of adults/bachelors and very few calves. On the other hand, swimming pods of calves were accompanied by one or two leading adults around icebergs. Our interpretation is that, after the beginning of the reproduction period with trios (cow, calf and future father) scattered on pack ice, such pods can be considered the last step of the breeding cycle

Mini-livestock breeding with indigenous species in the tropics

Mini-livestock encompasses small indigenous vertebrates and invertebrates which can be produced on a sustainable basis for food, animal feed and as a source of income. It includes bush rodents, guinea-pigs, frogs, giant snails, manure worms, insects and many other small species. Mini-livestock production is suitable for backyard family production and can contribute to increased food security. Extension and research are still lacking in many countries due to a traditional emphasis on large domestic animals and a lack of related training and education. However, whilst promoting mini-livestock it should be noted that some of these small animals can represent a serious threat as crop pests. Any zoonotic implications also need to be identified. Mini-livestock development is associated with the desirable long-term preservation of biodiversity. Given the need, awareness and increasing information now available on mini-livestock species it is time for increased investment in this form of sustainable production.SCOPUS: ar.jinfo:eu-repo/semantics/publishe