Effect of variation in tillage on weeds and groundnut establishment and yield in Rahad project, Sudan

Four tillage systems were compared under groundnut (Arachis hypogaea L.). These systems included: minimum tillage, disc plough and disc harrow, two disc harrows, and one disc harrow. Various weed data, emergence data and yield were used as parameters for comparison.

The number of weeds, weed ground cover, crop emergence rate index (ERI) and crop percent emergence (PE) were not affected by the different tillage systems. Yield data showed no significant difference for the two seasons of the experiment. The ridge-formation operation seemed to cancel any differences between tillage treatments. From these results, it appears that minimum tillage could be adopted as a practice for groundnut in the Rahad Agricultural Project.     

Domestic Sewage and Oil Spills in Streams: Effects on Edaphic Invertebrates in Flooded Forest, Manaus, Amazonas, Brazil

The influence of the aquatic environment on the terrestrial environment in areas subject to natural seasonal flooding has been little studied; especially lacking are studies that include anthropogenic impacts on these areas. Soil samples (including a superficial layer of litter) were collected between September 2000 and May 2001 on the banks of three streams in Manaus, Amazonas, Brazil in four seasons of the year, as determined by the flood pulse of the Rio Negro. The objectives of this study were to verify how an oil spill and urban sewage affect the abundance and richness of edaphic invertebrates on the stream banks and if these forms of pollution also influence the effect of the flood pulse on the natural community. Our results suggest reductions in the abundance and richness of edaphic invertebrates in the impacted areas and changes in the composition of edaphic invertebrate communities show a disturbance gradient from the banks of the unimpacted stream (Cristalino) to the banks of the stream that was impacted by the oil spill (Cururu), with more similar patterns occurring in impacted streams. The streams also showed effects of the flood pulse. Acarina, Entomobryidae, Formicidae, Staphylinidae and Carabidae were the only taxa that occurred in all three of the areas studied and in all of the sampling periods.     

The relationship between fruit size and cell division and enlargement in cultivated and wild persimmons

Summary

To determine the anatomical basis for differences in fruit size in Japanese persimmon (Diospyros kaki Thunb.), the number and sizes of parenchymal cells were measured in four astringent cultivars and in wild D. lotus over a single season in Japan. Fruit weight at harvest correlated with the final number of parenchymal cells (r = 0.95*) and their size (r = 0.92*). There was also a correlation between fruit diameter and the number of cell layers at full bloom (r = 0.93*), which increased 1.7 – 1.9-fold during fruit development.The duration of cell division and the sizes of the cells at full bloom were similar among the cultivars, whereas mean parenchymal cell lengths increased by 7.7-, 6.7-, 5.4-, 5.0- and 3.8-fold from full bloom to harvest in ‘Otanenashi’ (average fruit diameter = 96 mm), ‘Hiratanenashi’ (77 mm), ‘Saijo’ (54 mm), ‘Tsurunoko’ (44 mm), and D. lotus (20 mm), respectively. The final size of tannin cells was larger in ‘Otanenashi’ and ‘Hiratanenashi’ than in the other cultivars, including the wild species.These results indicate that the size of fruit at harvest was determined by the number of cells at full bloom, and their expansion during fruit development.     

Impacts of land use and topography on the cooling effect of green areas on surrounding urban areas

Few studies have examined the influence of land use and terrain on the cooling effect of green areas on surrounding urban areas. We investigated the spatial distribution of the cooling effect of green areas on surrounding urban areas in Heiwa Park, Nagoya, central Japan, by applying surface temperature (T_s) information obtained from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image data. The cooling effect was found to extend in many directions into the urban areas. The spatial distribution of T_s showed that commercial areas interrupted the flow of park cooling, whereas other types of urban areas expanded park cooling more effectively. We hypothesise that this was the result of differences in geometric and thermal properties and anthropogenic heat release between commercial and other areas. The spatial distribution of T_s also reflected the effects of topography on park cooling. The green area at our study site was located on a hill, and the downward slope and valley terrain inside the park increased the cooling effect towards the surrounding urban areas. To improve the thermal environment of urban areas and the comfort levels of residents, effective utilisation of the cooling effect of green areas should be incorporated into urban designs that consider the effects of land use and topography.     

Haloarchaea as Cell Factories to Produce Bioplastics

Plastic pollution is a worldwide concern causing the death of animals (mainly aquatic fauna) and environmental deterioration. Plastic recycling is, in most cases, difficult or even impossible. For this reason, new research lines are emerging to identify highly biodegradable bioplastics or plastic formulations that are more environmentally friendly than current ones. In this context, microbes, capable of synthesizing bioplastics, were revealed to be good models to design strategies in which microorganisms can be used as cell factories. Recently, special interest has been paid to haloarchaea due to the capability of some species to produce significant concentrations of polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), and polyhydroxyvalerate (PHV) when growing under a specific nutritional status. The growth of those microorganisms at the pilot or industrial scale offers several advantages compared to that of other microbes that are bioplastic producers. This review summarizes the state of the art of bioplastic production and the most recent findings regarding the production of bioplastics by halophilic microorganisms with special emphasis on haloarchaea. Some protocols to produce/analyze bioplastics are highlighted here to shed light on the potential use of haloarchaea at the industrial scale to produce valuable products, thus minimizing environmental pollution by plastics made from petroleum.     

Mining Indonesian Microbial Biodiversity for Novel Natural Compounds by a Combined Genome Mining and Molecular Networking Approach

Indonesia is one of the most biodiverse countries in the world and a promising resource for novel natural compound producers. Actinomycetes produce about two thirds of all clinically used antibiotics. Thus, exploiting Indonesia’s microbial diversity for actinomycetes may lead to the discovery of novel antibiotics. A total of 422 actinomycete strains were isolated from three different unique areas in Indonesia and tested for their antimicrobial activity. Nine potent bioactive strains were prioritized for further drug screening approaches. The nine strains were cultivated in different solid and liquid media, and a combination of genome mining analysis and mass spectrometry (MS)-based molecular networking was employed to identify potential novel compounds. By correlating secondary metabolite gene cluster data with MS-based molecular networking results, we identified several gene cluster-encoded biosynthetic products from the nine strains, including naphthyridinomycin, amicetin, echinomycin, tirandamycin, antimycin, and desferrioxamine B. Moreover, 16 putative ion clusters and numerous gene clusters were detected that could not be associated with any known compound, indicating that the strains can produce novel secondary metabolites. Our results demonstrate that sampling of actinomycetes from unique and biodiversity-rich habitats, such as Indonesia, along with a combination of gene cluster networking and molecular networking approaches, accelerates natural product identification.     

Immunocytochemical component of endocrine cells in pancreatic islets of horses

The endocrine cell components in the pancreatic islets of the following 4 pancreatic regions of the horse were investigated by immunohistochemical methods: lobus pancreatis sinister (left lobe); lobus pancreatis dexter (right lobe); and 2 regions of Corpus pancreatis (body), the duodenal lobe which lies along the cranial duodenal flexure and descending duodenum, and the intermediate lobe which is situated around the portal vein. The islets in the left and intermediate lobes contained a central mass of glucagon cells surrounded by insulin cells, a few somatostatin cells and sporadic pancreatic polypeptide (PP) cells. On the other hand, the islets in the duodenal lobe were small in size compared with the other 3 regions, and were predominant in insulin and pancreatic polypeptide (PP) cells, but almost lacked in glucagon cells. These findings suggested that the duodenal lobe was derived from the ventral pancreatic primordium, and the left and intermediate lobes were originated from the dorsal pancreatic primordium. In the right lobe, the composition and distribution of the islet cells were almost the same as those in the left and intermediate lobes, but there were several lobules containing numerous PP cells as seen in the duodenal lobe.     

Relationship between soil neutral sugar composition and the amount of labile soil organic matter in Andisol treated with bark compost or leaf litter

 The effect of short-term bark compost (Ba) and leaf litter (Li) applications on the labile soil organic matter (SOM) status was investigated. The SOM status studied in this paper includes soil microbial biomass, soil available N, hot water extractable C (HwC) and N (HwN) and soil neutral sugar-C composition. The soil microbial biomass C (MBC) and N (MBN), soil available N, HwC and HwN increased upon application of Ba and Li. No quantitative relationship was observed between application of organic material and MBC, MBN or soil available N. A positive linear correlation was observed between MBN and HwC but not between MBN and soil available N. Among the various soil neutral sugar C, xylose C (Xyl) content in Ba plots showed a remarkable increase but mannose C (Man) did not differ among Fer (fertilizer), Ba or Li plots. Soil neutral sugar C had a positive linear correlation with soil available N, MBN and HwC. The proportion of MBN : TN is positively correlated with the Xyl/Man ratio. The increase in the proportion of MBN in SOM seems to occur with the increase of SOM derived from plant debris. Received: 20 October 1997     

Inhibitory effects of edible marine algae extracts on degranulation of RBL-2H3 cells and mouse eosinophils

Inhibitory effects on degranulation of rat basophilic leukemia (RBL-2H3) cells and mouse eosinophils by marine algae extracts were examined. More than 50% of the degranulation of RBL-2H3 cells was inhibited by water extracts of Ecklonia cava and Chrysymenia wrightii at a concentration of 100 μg/mL. More than 50% of the degranulation of RBL-2H3 cells was inhibited by methanol extracts of Petalonia binghamiae, Scytosiphon lomentaria, Undaria pinnatifida, Porphyra dentata, Codium fragile and Ulva japonica at a concentration of 200 μg/mL. Most inhibitory substances in the methanol extracts were partitioned into ethyl acetate and hexane layers. The ethyl acetate-partitioned layer of methanol extract of Petalonia binghamiae had higher inhibitory effects than the hexane-partitioned layer on the degranulation of RBL-2H3 cells. By contrast, the hexanepartitioned layer of the same extract had a higher inhibitory effect than the ethyl acetate-partitioned layer on the degranulation of mouse eosinophils. The ethyl acetate-partitioned layer of methanol extract of Petalonia binghamiae was further separated into eight fractions by silica gel column chromatography. Most inhibited the degranulation of RBL-2H3 cells, but not that of mouse eosinophils significantly. These results suggest methanol extract of Petalonia binghamiae contains materials that inhibit the degranulation of basophils and eosinophils differentially.     

Molecular and Evolutionary Analysis of the Hd6 Photoperiod Sensitivity Gene Within Genus Oryza

Heading date determines rice’s adaptation to its area and cropping season. We analyzed the molecular evolution of the Hd6 quantitative trait locus for photoperiod sensitivity in a total of 20 cultivated varieties and wild rice species and found 74 polymorphic sites within its coding region (1,002 bp), of which five were nonsynonymous substitutions. Thus, natural mutations and modifications of the coding region of Hd6 within the genus Oryza have been suppressed during its evolution; this is supported by low Ka (≤0.003) and Ka/Ks (≤0.576) values between species, indicating purifying selection for a protein-coding gene. A nonsynonymous substitution detected in the japonica variety “Nipponbare” (a premature stop codon and nonfunctional allele) was found within only some local Japanese japonica varieties, which suggests that this point mutation happened recently, probably after the introduction of Chinese rice to Japan, and is likely involved in rice adaptation to high latitudes. Phylogenetic analysis and genome divergence using the entire Hd6 genomic region confirmed the current taxonomic sections of Oryza and supported the hypothesis of independent domestication of indica and japonica rice.