Valuation of Rice Postharvest Losses in Sub-Saharan Africa and Its Mitigation Strategies

正Data on rice harvest and postharvest loss in Sub-Sahara Africa(SSA) is scanty making it difficult for stakeholders to appreciate the loss and set priority areas for loss reduction along the value chain. To address this problem, a protocol was developed and validated for postharvest loss(PHL) quantification in SSA. Quantitative losses at each segment were determined by field measurements.     

Fish assemblages of an African river floodplain: a test of alternative models of community structure

In the Oueme River, a lowland river in Benin, Africa, artificial ponds constructed in the floodplain (whedos) are colonised during the high‐water period by a presumably random sample of fishes from the river channel. As water slowly recedes from the floodplain, fishes are isolated in whedos until they are harvested near the end of the dry season. We surveyed fishes in whedos and adjacent main‐channel and floodplain habitats during two low‐water periods (2008 and 2009) and one falling‐water period (2010–2011) to evaluate the relevance of four alternative metacommunity models to these systems. In 2010–2011, we also measured a suite of physicochemical variables including dissolved oxygen, temperature, specific conductivity and per cent cover of aquatic vegetation. Whedos were covered with dense growth of aquatic vegetation, and dissolved oxygen concentrations were lower in whedos and a natural floodplain depression compared with the main channel. Multivariate analyses revealed that habitat types were distinct with regard to assemblage structure and abiotic conditions. Assemblages in whedos and natural floodplain depressions were differentiated from those of the river channel, with the floodplain habitats being dominated by piscivorous fishes that tolerate aquatic hypoxia. Dispersal, aquatic hypoxia and predation act in concert to shape local community structure. Patch dynamics, species sorting and mass effect models all were consistent with patterns in fish assemblage structure in this system. We conclude that the underlying mechanisms of drift, speciation, selection and dispersal ultimately may be more useful for explaining patterns in ecological communities than alternative metacommunity models.     

Residual effect after salmon oil supplementation on semen quality and serum levels of testosterone in dogs

The objective of present study was to evaluate the effects of oral supplementation of salmon oil on seminal parameters and testosterone serum levels in dogs, following also the residual effects for 60 days after treatment. Nine healthy male dogs with proven fertility, weighing between 10 and 36 kg, ageing from 2 to 11 years, of different breeds, fed diets supplemented with salmon oil at the manufacturer's recommended dosage. The parameters measured were sperm volume, motility, vigour, normal morphology and concentration, live/dead ratio, membrane viability by means of HOST test and serum testosterone levels. Evaluations occurred at baseline (D0), after 90 days of supplementation (D90) and at the end of the experiment, 60 days after supplementation cessation (D150). Results (mean ± SD) obtained at time D0, D90 and D150 were as follows: motility of 76.66% ± 13.7, 92.77 ± 4.41 and 93.0 ± 7.90 (p = .001); normal spermatozoa of 69.11% ± 24.90, 90.00% ± 5.15 and 80.66 ± 16.04 (p = .05); live/dead (%) from 64.44 ± 22.86 to 85.33 ± 8.41 (p = .001); and spermatozoa (%) with integral membrane in the membrane integrity (HOST) test ranging from 76.44 ± 20.74 to 91.22 ± 4.68 (p = .05). Serum levels of testosterone (ng/ml) increased from 5.50 ± 1.13 to 8.84 ± 1.13 at D90 (p = .003) and decreased after 2 months (D150) to 5.13 ± 1.13. In conclusion, a 90‐day supplementation with salmon oil had a positive influence on semen quality and serum testosterone levels. The supplementation of omegas 3 and 6 at the ratio of 10:1 for 90 days determined an increase in concentration and motility of the sperm, and these effects were maintained for 60 days, with the only exception of testosterone levels.     

Correlations between the biochemistry and mechanical states of a sea-urchin ligament: a mutable collagenous structure

Mutable collagenous tissues (MCTs) of echinoderms can be regarded as intelligent and dynamic biomaterials, due to their ability to reversibly change their mechanical properties in a short physiological time span. This mutability phenomenon is nervously mediated and involves secreted factors of the specialized 'juxtaligamental' cells, which, when released into the extracellular matrix (ECM), change the cohesive forces between collagen fibrils. MCTs exist in nature in several forms, including some associated with echinoderm autotomy mechanisms. Since the molecular mechanism of mutability is still incompletely understood, the aim of this work was to provide a detailed biochemical analysis of a typical mutable collagenous structure and to identify possible correlations between its biochemistry and mechanical states. A better understanding of the mutability phenomena is likely to provide a unique opportunity to develop new concepts that can be applied in the design of dynamic biomaterial for tissue regeneration, leading to new strategies in regenerative medicine. The MCT model used was the compass depressor ligament (CDL) of a sea urchin (Paracentrotus lividus), which was analyzed in different mechanical states, mimicking the mutability phenomenon. Spectroscopic techniques, namely Fourier transform infrared (FT-IR) and confocal Raman microscopy, were used to identify the specific molecular components that contribute to the CDL biochemical microenvironment and to investigate the possibility that remodelling/synthesis of new ECM components occurs during the mutability phenomenon by analogy with events during pregnancy in the uterine cervix of mammals (which also consists mainly of mechanically adaptable connective tissues). The results demonstrate that CDL ECM includes collagen with biochemical similarities to mammalian type I collagen, as well as sulphated glycosaminoglycans (GAGs). CDL mutability seems to involve a molecular rearrangement of the ECM, without synthesis of new ECM components. Although there were no significant biochemical differences between CDLs in the various mechanical states were observed. However, subtle adjustments in tissue hydration seemed to occur, particularly during stiffening.