The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

Loach Sperm Cells Transfer Foreign DNA Expressed in Early Development

The transfer of plasmid pcDNA3-lacZ by electrotrasfected sperm cells into loach (Misgurnus fossilis L.) ova has been studied. The lacZ gene has been found to express in 3- to 5-day-old prelarvae.     

Substitution rates of organelle and nuclear genes in sharks: implicating metabolic rate (again)

Rates of nucleotide substitution for nuclear genes are thought to be governed primarily by the number of germ line replication events (the so-called "generation time" hypothesis). In contrast, rates of mitochondrial DNA evolution appear to be set primarily by DNA damage pathways of mutation mediated by mutagenic by-products of oxidative phosphorylation (the so-called "metabolic-rate" hypothesis). Comparison of synonymous substitution rates estimated for the mitochondrial cytochrome b gene and nuclear-encoded dlx, hsp70, and RAG-1 genes in mammals and sharks shows that rates of molecular evolution for sharks are approximately an order of magnitude slower than those for mammals for both nuclear and mitochondrial genes. In addition, there is significant positive covariation of substitution rate for mitochondrial and nuclear genes within sharks. These results, interpreted in light of the pervasiveness of DNA damage by mutagenic by-products of oxygen metabolism to both nuclear and mitochondrial genes and coupled with increasing evidence for cross-genome activity of DNA repair enzymes, suggest that molecular clocks for mitochondrial and nuclear genes may be set primarily by common mutational mechanisms.      

Survival Rate and Enzyme Activities ofLactobacillus acidophilusFollowing Frozen Storage

The ability of two strains of Lactobacillus acidophilus, CRL 640 and CRL 800, to survive and retain their biological activities under frozen storage was determined. Freezing and thawing, as well as frozen storage, damaged the cell membrane, rendering the microorganisms sensitive to sodium chloride and bile salts. Both lactic acid production and proteolytic activity were depressed after 21 days at -20 degreesC, whereas beta-galactosidase activity per cell unit was increased. Cell injury was partially overcome after repair in a salt-rich medium. Copyright 1998 Academic Press.     

Elemental distribution in striated muscle and the effects of hypertonicity: Electron probe analysis of cryo sections

A method of rapid freezing in supercooled Freon 22 (monochlorodifluoromethane) followed by cryoultramicrotomy is described and shown to yield ultrathin sections in which both the cellular ultrastructure and the distribution of diffusible ions across the cell membrane are preserved and intracellular compartmentalization of diffusabler ions can be quantitated. Quantitative electron probe analysis (Shuman, H., A.V. Somlyo, and A.P. Somlyo. 1976. Ultramicros. 1:317-339.) of freeze-dried ultrathin cryto sections was found to provide a valid measure of the composition of cells and cellular organelles and was used to determine the ionic composition of the in situ terminal cisternae of the sarcoplasmic reticulum (SR), the distribution of CI in skeletal muscle, and the effects of hypertonic solutions on the subcellular composition if striated muscle. There was no evidence of sequestered CI in the terminal cisternae of resting muscles, although calcium (66mmol/kg dry wt +/- 4.6 SE) was detected. The values of [C1](i) determined with small (50-100 nm) diameter probes over cytoplasm excluding organelles over nuclei or terminal cisternae were not significantly different. Mitochondria partially excluded C1, with a cytoplasmic/ mitochondrial Ci ratio of 2.4 +/- 0.88 SD. The elemental concentrations (mmol/kg dry wt +/- SD) of muscle fibers measured with 0.5-9-μm diameter electron probes in normal frog striated muscle were: P, 302 +/- 4.3; S, 189 +/- 2.9;C1, 24 +/- 1.1;K, 404 +/- 4.3, and Mg, 39 +/- 2.1. It is concluded that: (a) in normal muscle the "excess CI" measured with previous bulk chemical analyses and flux studies is not compartmentalized in the SR or in other cellular organelles, and (b) the cytoplasmic C1 in low [K](0) solutions exceeds that predicted by a passive electrochemical distribution. Hypertonic 2.2 X NaCl, 2.5 X sucrose, or 2.2 X Na isethionate produced: (a) swollen vacuoles, frequently paired, adjacent to the Z lines and containing significantly higher than cytoplasmic concentrations of Na and Cl or S (isethionate), but no detectable Ca, and (b) granules of Ca, Mg, and P = approximately (6 Ca + 1 Mg)/6P in the longitudinal SR. It is concluded that hypertonicity produces compartmentalized domains of extracellular solutes within the muscle fibers and translocates Ca into the longitudinal tubules.     

Cytoarchitectonics of ileocecal lymph nodes in newborn and sexually mature simians (pavian hamadrils)]

Cell composition of various components (cortical plateau, folliculi and cords) of ileocecal lymph nodes was studied in newborn, 1.5 and 2.5 months of age (2 animals) and in mature (3 animals) monkeys, Papio hamadryas. In histological sections obtained at the level of hilus of the lymph node cellular elements were counted by means of morphometric grid of Glagolev modifoed by S. B. Stefanov. The data obtained were statistically treated. Newborn and mature monkeys have their peculiar cytological profile in every structural component of the lymph node. The lymph nodes in the newborns contain much more reticular cells and young cellular forms (blast forms and large lymphocytes) than mature animals. In the newborns, the number of mitotically deviding cells in the cortical plateau and in folliculi is 6 times and in myelin cords 10 times as great as in mature monkeys. A much greater per cent of plasmatic cells in mature animals suggests their greater immunological activity. Age differences in cell composition of lymph nodes in young and mature monkeys seem to be connected with accumulation of cellular mass and growth of the node in young animals, as well as with general rearrangement of the organism as a whole (in particular with changes in nutrition, intensity of movement, hormonal background).     

The Impact of the West Africa Ebola Outbreak on Obstetric Health Care in Sierra Leone

Background

As Sierra Leone celebrates the end of the Ebola Virus Disease (EVD) outbreak, we can begin to fully grasp its impact on already weak health systems. The EVD outbreak in West Africa forced many hospitals to close down or reduce their activity, either to prevent nosocomial transmission or because of staff shortages. The aim of this study is to assess the potential impact of EVD on nationwide access to obstetric care in Sierra Leone.

Methods and Findings

Community health officers collected weekly data between January 2014—May 2015 on in-hospital deliveries and caesarean sections (C-sections) from all open facilities (public, private for-profit and private non-profit sectors) offering emergency obstetrics in Sierra Leone. This was compared to official data of EVD cases per district. Logistic and Poisson regression analyses were used to compute risk and rate estimates. Nationwide, the number of in-hospital deliveries and C-sections decreased by over 20% during the EVD outbreak. The decline occurred early on in the EVD outbreak and was mainly attributable to the closing of private not-for-profit hospitals rather than government facilities. Due to difficulties in collecting data in the midst of an epidemic, limitations of this study include some missing data points.

Conclusions

Both the number of in-hospital deliveries and C-sections substantially declined shortly after the onset of the EVD outbreak. Since access to emergency obstetric care, like C-sections, is associated with decreased maternal mortality, many women are likely to have died due to the reduced access to appropriate care during childbirth. Future research on indirect health effects of health system breakdown should ideally be nationwide and continue also into the recovery phase. It is also important to understand the mechanisms behind the deterioration so that important health services can be reestablished.     

Coupling between the BLUF and EAL domains in the blue light-regulated phosphodiesterase BlrP1

The first biochemical and structural characterization of the full-length active photoreceptor BlrP1 from Klebsiella pneumoniae was recently reported by Barends et al. [Nature 459:1015–1018, (2009)]. The light-regulated catalytic function of its C-terminal c-di-guanosine monophosphate phosphodiesterase, the EAL (Glu-Ala-Leu) domain, is activated by the N-terminal sensor of blue light using the flavin adenine dinucleotide (BLUF) domain. We performed molecular dynamics simulations on the dimeric BlrP1 protein in order to examine the coupling regions that are presumably involved in transmitting light-induced structural changes which occur in the BLUF domain to the EAL domain. According to the results of simulations and an analysis of the hydrogen bonding between the respective polypeptide chains, the region containing the site on the α3α4 loop of BLUF is responsible for communication between the photosensing and catalytic domains in the dimeric BlrP1 protein.