A Coloring Algorithm for Disambiguating Graph and Map Drawings

Drawings of non-planar graphs always result in edge crossings. When there are many edges crossing at small angles, it is often difficult to follow these edges, because of the multiple visual paths resulted from the crossings that slow down eye movements. In this paper we propose an algorithm that disambiguates the edges with automatic selection of distinctive colors. Our proposed algorithm computes a near optimal color assignment of a dual collision graph, using a novel branch-and-bound procedure applied to a space decomposition of the color gamut. We give examples demonstrating the effectiveness of this approach in clarifying drawings of real world graphs and maps

Unraveling the secrets of rhizobacteria signaling in rhizosphere

Signaling among rhizobacteria and other soil microorganisms is an important mechanism to ensure a successful symbiotic relationship with their phytobionts. Quorum-sensing involves signaling molecules that provide essential networks for communication in the rhizosphere. These signaling molecules relay inter-and-intra-species information that coordinates and controls behavior in mixed communities, and the expression of these signaling molecules changes in response to the chemical cues. The diverse signaling molecules released in the rhizospheric zone affect the structural and physical heterogeneity of the soil and the quantity and identity of rhizobacteria. In general, rhizospheric signaling mechanisms can be categorized into three major types (i) plant to microorganisms signaling through low molecular weight molecules secreted by plants; (ii) interspecies and intraspecies microbial signaling, chiefly through quorum-sensing molecules; and (iii) microorganisms to plant signaling by microbially produced compounds. This review presents knowledge on the signaling molecules of the rhizosphere based on the above three mechanisms. The chemical nature of root exudates and their roles in attracting metabolically active rhizobacteria; the chemical properties of autoinducers secreted by rhizobacteria and their functions in intra- and inter-species interactions, including biofilm formation in the rhizosphere; and influence of quorum sensing on the root architecture, plant defense and biotic and abiotic stress responses, and gene expression are examined. The review provides a thorough understanding of rhizobacteria signaling and will help to develop novel strategies for agriculture, such as the novel use of plant growth-promoting rhizobacteria to enhance crops growth and quorum quenching technique to fight against plant pathogens

Residual pollutants in treated pulp paper mill wastewater and their phytotoxicity and cytotoxicity in Allium cepa

Discharged pulp and paper mill wastewater (PPMW) were collected near M/s K. R. pulp and papers Limited, Shahjahanpur, India. Chemical analysis of the wastewater showed high BOD (3653-4180 mg L-1) and COD (17890-19100 mg L-1) values from two different sampling sites. The levels of total phenol were in the range of 389-432 mg L-1, nitrogen (125-234 mg L-1), sulfate (1926-2098 mg L-1), chloride (3.12-5.43 mg L-1) and lignin (38950-39000 mg L-1) along with various heavy metals (Fe, 87-79; Zn, 34-22; Cu, 3.28-2.57; Cd, 1.90- 0.36; Ni, 6-5, and Pb, 41.23-36.54 mg L-1); these were above the permissible limit as recommended by the CPCB and the USEPA. The BOD/COD ratio was 20% concentration of PPMW, α-amylase production was inhibited and chromosomal segregation at metaphase and anaphase during cell division was disturbed which resulted in c-mitosis, sticky chromosomes, and laggard chromosomes. In addition, SEM of the root of A. cepa showed fissures and fractured tissues of the root cap, probably due to the inhibition of auxins that were responsible for root cap formation. The findings indicated A. cepa as a good test model for examining the DNA damage and cytotoxicity by PPMW; and the discharged effluent should be treated at the tertiary stage for environmental protection

Sir John Cornforth AC CBE FRS: his biosynthetic work

Sir John Cornforth’s work on the stereochemistry of enzyme reactions involved in the biosynthesis of squalene and cholesterol and in the formation and metabolism of a chiral methyl group in acetyl co-enzyme A, is reviewed

Integrating phytoremediation into treatment of pulp and paper industry wastewater: Field observations of native plants for the detoxification of metals and their potential as part of a multidisciplinary strategy

This work aimed to explore the use of native herbs for the removal of heavy metals from pulp and paper industry wastewater, with the view of applying them as part of a multidisciplinary approach for detoxification. Results showed that after in-situ phytoremediation by the native herbs, the heavy metal, and metalloid contents in the wastewater were reduced by almost 60%. Heavy metal analysis of the plant tissues revealed that Fe accumulation was highest in all the tested plants. In general, the bioconcentration factor (BCF) was higher than one (>1) for all the metals except for Cd, suggesting most of the metals were concentrated in the plant tissues. In particular, As was concentrated significantly in Momordica doica and Cannabis sativa with elevated BCF of 269.46 and 131.20, respectively. High translocation factor (>1) was observed in P. hysterophorus and Tribulus terrestris for Cr (5.63) and Cd (7.53), respectively. Results showed most of the native plants examined in this study had hyperaccumulating tendency. Transmission electron microscope analysis of plant root tissues showed abundant metal depositions in the root cell wall, cytoplasm, and vacuole as strong evidence of the in-situ phytoremediation capability of these plants. Antioxidants activities of the plants such as superoxide dismutase, catalase, hydrogen peroxidase, peroxidase, and ascorbate peroxidase production were also noted to be higher than the control. These results support the use of native plants as a novel green process that can be integrated into the multidisciplinary treatment of hazardous industrial wastewater in the polluted sites

Degradation and detoxification of leather tannery effluent by a newly developed bacterial consortium GS-TE1310 for environmental safety

The untreated/partially treated effluent discharged from leather tanning industries is heavily polluting our water and soil resources. Hence, the adequate treatment/detoxification of tannery effluent (TE) is required before its safe disposal into the environment. In the present study, an effective degradation of real TE was attained by a newly developed bacterial consortium GS-TE1310 within 120 h with 76.12, 85.32, 71.89, 48.59, 78.81, 69.53, 71.22, and 88.70 % reduction in pollution parameters such as COD, BOD, TDS, phosphate, sulphate, nitrate, Cr, and phenol, respectively. The HP-LC, FT-IR, and GC–MS study showed that most of the organic contaminants identified in the untreated TE were completely mineralized/degraded into new degradation products in the treated TE by the newly developed bacterial consortium GS-TE1310 at 7 pH, 0.5 % glucose and ammonium chloride, 120 rpm, and 20 mL inoculum volume. Further, the bacterially treated TE was used for the phytotoxicity evaluation using Phaseolus aureus L as a terrestrial model organism. Results revealed that the toxicity of bacterially treated TE was significantly reduced, allowing the 70 % germination of seeds, and thus, confirmed the detoxification of leather TE. Overall, the newly developed bacterial consortium GS-TE1310 demonstrated a remarkable potential to efficiently treat/detoxify leather TE for environmental safety

Distillery wastewater detoxification and management through phytoremediation employing Ricinus communis L.

This study aimed to assess the phytoremediation potential of Ricinus communis L. for heavy metals remediation via rhizospheric bacterial activities for distillery wastewater detoxification and management. Results revealed that distillery wastewater contained high levels of metals and other physico-chemical pollution parameters that could cause environmental pollution and aquatic toxicity. The identified bacterium produced several plant growth-promoting compounds including siderophores, ligninolytic enzymes, and indole acetic acid that resulted in nutrient enhancement and improved mineralization of metals in the plants during stress conditions. The bioconcentration factor (BCF) of all the metals examined were > 1, which showed that these metals are accumulating in the root, shoot, and leaves of Ricinus communis L. Most of the metals are stabilised in the roots but Pb, Cd and Zn were translocated more to the shoots (TC>1). The ability of Ricinus communis L. to grow in metals- containing distillery wastewater and reduce heavy metals and organic contaminants suggests that it can be used to provide an effective treatment of distillery wastewater. The use of Ricinus communis L. is an eco-friendly tool for the reduction of organometallic contamination and protecting agricultural land

Microbial community dynamics and their relationships with organic and metal pollutants of sugarcane molasses-based distillery wastewater sludge

Distillery sludge is a major source of aquatic pollution, but little is known about their microbial community and their association with the organic and metal pollutants. Sugarcane molasses-based distillery is an important industry in India, although the waste is usually treated prior to disposal, the treatment is often inadequate. The adverse effects of the organic and metal pollutants in sugarcane molasses-based distillery sludge on the microbial biodiversity and abundance in the disposal site have not been elucidated. This study aims to address this gap of knowledge. Samples were collected from the discharge point, 1 and 2 km downstream (D1, D2, and D3, respectively) of a sugarcane distillery in Uttar Pradesh, India, and their physico-chemical properties characterised. Using QIIME, taxonomic assignment for the V3 and V4 hypervariable regions of 16S rRNA was performed. The phyla Proteobacteria (28-39%), Firmicutes (20-28%), Bacteriodetes (9-10%), Actinobacteria (5-10%), Tenericutes (1-9%) and Patescibacteria (2%) were the predominant bacteria in all three sites. Euryechaeota, were detected in sites D1 and D2 (1-2%) but absent in D3. Spirochaetes (5%), Sinergistetes (2%) and Cloacimonetes (1%) were only detected in samples from site D1. Shannon, Simpson, Chao1, and Observed-species indices indicated that site D1 (10.18, 0.0013, 36706.55 and 45653.84, respectively) has higher bacterial diversity and richness than D2 (6.66, 0.0001, 25987.71 and 49655.89, respectively) and D3 (8.31, 0.002, 30345.53 and 30654.88, respectively), suggesting the organic and metal pollutants provided the stressors to favour the survival of microbial community that can biodegrade and detoxify them in the distillery sludge. This study confirmed that the treatment of the distillery waste was not sufficiently effective and provided new metagenomic information on its impact on the surrounding microbial community. It also offered new insights into potential bioremediation candidates

The association of food ingredients in breakfast cereal products and fumonisins production: risks identification and predictions

Breakfast processed products are remarkably at risk of fungal contamination. This research surveyed the fumonisins concentration in different breakfast products, and carried out in-vitro experiments measuring fumonisins content in different substrates inoculated with Fusarium verticillioides. The pipeline started with the identification of combinations of ingredients for 58 breakfast products. Twenty-three core ingredients, seven nutritional components and production types were analyzed using a Pearson correlation, k-means clustering and principal component analysis to show that no single factor is responsible for high fumonisins detection in processed cereals products. Consequently, decision tree regression was used as a means of determining and visualizing complex logical interactions between the same factors. We clustered the association of ingredients in low, medium, and high risk of fumonisin detection. The analysis showed that high fumonisins concentration is associated with those products that have high maize concentrations coupled especially with high sodium or rice. In a in-vitro experiment, different media were prepared by mixing the ingredients in the proportion found in the first survey and by measuring fumonisins production by Fusarium verticillioides. Results showed that: 1) fumonisins production by F. verticillioides is boosted by the synergistic effect of maize and highly ready carbohydrate content such as white flour; 2) a combination of maize >26%(w/w), rice >2.5%(w/w), NaCl >2.2%(w/w) led to high fumonisins production, while mono-ingredient products were more protective against fumonisins production. The observations in the in-vitro experiments appeared to align with the decision tree model that an increase in ingredient complexity can lead to fumonisins production by Fusarium. However, more research is urgently needed to develop the area of predictive mycology based on the association of processing, ingredients, fungal development, and mycotoxins production

Visual Similarity Perception of Directed Acyclic Graphs: A Study on Influencing Factors

While visual comparison of directed acyclic graphs (DAGs) is commonly encountered in various disciplines (e.g., finance, biology), knowledge about humans' perception of graph similarity is currently quite limited. By graph similarity perception we mean how humans perceive commonalities and differences in graphs and herewith come to a similarity judgment. As a step toward filling this gap the study reported in this paper strives to identify factors which influence the similarity perception of DAGs. In particular, we conducted a card-sorting study employing a qualitative and quantitative analysis approach to identify 1) groups of DAGs that are perceived as similar by the participants and 2) the reasons behind their choice of groups. Our results suggest that similarity is mainly influenced by the number of levels, the number of nodes on a level, and the overall shape of the graph.Comment: Graph Drawing 2017 - arXiv Version; Keywords: Graphs, Perception, Similarity, Comparison, Visualizatio