The feasibility of milkfish (Chanos chanos) aquaculture in Solomon Islands

Fish is crucial to food and nutrition security in Solomon Islands, and demand is expected to increase due to a growing population. However, it is projected that current capture fisheries production will not meet this growing demand. Aquaculture has the potential to mitigate the capture fishery shortfall, and the Government of Solomon Islands is prioritizing aquaculture as a solution to meet future food and income needs. Aquaculture in Solomon Islands is still in early development. Mozambique tilapia (Oreochromis mossambicus) is farmed for household consumption, but its prolific reproductive rate and resulting slow growth limit its potential as a commercial aquaculture species. More productive fish species that are not indigenous to Solomon Islands but are successfully farmed overseas could be introduced; however, such a decision needs to take into account the potential ecological or social impacts. For land-based pond aquaculture, the only indigenous species that has been farmed extensively elsewhere is milkfish (Chanos chanos). This report presents a feasibility assessment for milkfish farming in Solomon Islands. It synthesizes the current knowledge about milkfish farming and presents results of a 4-year study on the potential for milkfish aquaculture in Solomon Islands

Malaria prevalence and morbidity among children reporting at health facilities in Nouakchott, Mauritania

Although malaria has become a serious public health problem in Mauritania since the late 1990s, few documented data on its epidemiology exist. The objective of this study was to assess the morbidity of clinical malaria among children in Nouakchott. Three hundred and one febrile children, consulting at three health facilities of Nouakchott, were screened for malaria in 2009(n = 216) and 2010(n = 85). Plasmodium species identification and parasite density were determined by microscopic examination of Giemsa-stained thin and thick films and confirmed by rapid diagnostic test and nested PCR. Of 301 febrile children, 105 (34.9%) were malaria-positive by nested PCR and 87 (28.9%) by microscopy. Plasmodium vivax represented 97.1% (102/105) and P. falciparum accounted for 2.9% (3/105) of positive cases. All positive children under five years old were infected with P. vivax. The highest numbers of malaria positives were found during or shortly after the rainy season and the lowest during the dry season. Fifty-four of 105 (51.4%) malaria cases, all with P. vivax, had never travelled outside Nouakchott. Individuals belonging to the Moors ethnic group represented 97.0% of P. vivax cases. Results of the present study indicate that malaria is endemic in Nouakchott and that P. vivax is the principal causative agent. Regular surveillance is required to monitor malaria prevalence and incidence, and further measures are needed to counter the possible spread of malaria in the country

Pkh1 and Pkh2 Differentially Phosphorylate and Activate Ypk1 and Ykr2 and Define Protein Kinase Modules Required for Maintenance of Cell Wall Integrity

Saccharomyces cerevisiae Pkh1 and Pkh2 are functionally redundant homologs of mammalian protein kinase, phosphoinositide-dependent protein kinase-1. They activate two closely related, functionally redundant enzymes, Ypk1 and Ykr2 (homologs of mammalian protein kinase, serum- and glucocorticoid-inducible protein kinase). We found that Ypk1 has a more prominent role than Ykr2 in mediating their shared essential function. Considerable evidence demonstrated that Pkh1 preferentially activates Ypk1, whereas Pkh2 preferentially activates Ykr2. Loss of Pkh1 (but not Pkh2) reduced Ypk1 activity; conversely, Pkh1 overexpression increased Ypk1 activity more than Pkh2 overexpression. Loss of Pkh2 reduced Ykr2 activity; correspondingly, Pkh2 overexpression increased Ykr2 activity more than Pkh1 overexpression. When overexpressed, a catalytically active C-terminal fragment (kinase domain) of Ypk1 was growth inhibitory; loss of Pkh1 (but not Pkh2) alleviated toxicity. Loss of Pkh2 (but not Pkh1) exacerbated the slow growth phenotype of a ypk1Δ strain. This Pkh1-Ypk1 and Pkh2-Ykr2 dichotomy is not absolute because all double mutants (pkh1Δ ypk1Δ, pkh2Δ ypk1Δ, pkh1Δ ykr2Δ, and pkh2Δ ykr2Δ) were viable. Compartmentation contributes to selectivity because Pkh1 and Ypk1 were located exclusively in the cytosol, whereas Pkh2 and Ykr2 entered the nucleus. At restrictive temperature, ypk1-1(ts) ykr2Δ cells lysed rapidly, but not in medium containing osmotic support. Dosage and extragenic suppressors were selected. Overexpression of Exg1 (major exoglucanase), or loss of Kex2 (endoprotease involved in Exg1 processing), rescued growth at high temperature. Viability was also maintained by PKC1 overexpression or an activated allele of the downstream protein kinase (BCK1-20). Conversely, absence of Mpk1 (distal mitogen-activated protein kinase of the PKC1 pathway) was lethal in ypk1-1(ts) ykr2Δ cells. Thus, Pkh1-Ypk1 and Pkh2-Ykr2 function in a novel pathway for cell wall integrity that acts in parallel with the Pkc1-dependent pathway