New insights into the supression of plant pathogenic fungus (Phytophthora cinnamomi) by compost leachates

Use of compost as a soil conditioner and low-grade fertiliser is gaining popularity worldwide (Epstein, 1997). Compost not only adds plant nutrients to the soil, but also improves physical properties of soil such as buffering capacity, cation exchange capacity and water holding capacity. In addition to these benefits, compost can also suppress plant diseases caused by Phytophthora cinnamomi (Hoitink et al., 1977), Pythium aphanidermatum (Mandelbaum and Hadar, 1990), Rhizoctonia solani and Sclerotium rolfoii (Gorodecki and Hadar, 1990). Irwin et al., (1995) reported that the diseases caused by P. cinnamomi are directly responsible for considerable economic losses in many horticultural, ornamental and forestry industries throughout Australia. Phytophthora spp. continue to be the focus of attention of many researchers due to the diversity of P. cinnamomi-host interactions and their potential economic impact on a wide range of industries. The practise of using methyl bromide and other chemicals for disinfection of soil is widespread (Trill as et al., 2002). However, the use of methyl bromide and other chemicals is phased out in the USA and Europe. The suppression of soil-borne plant fungus by composts produced from tree barks (Spencer et al., 1982) and municipal solid wastes is well documented (Trill as et al., 2002). Composts that suppress plant disease have been extensively described and are used in greenhouse production systems (Lazarovitis et aI, 2001). However, most studies have focused on compo sting different types of materials and their effect on fungal pathogens inhibition rather than compo sting conditions that may produce suppressive composts. An objective of this study was to investigate the role of moisture, aeration and compost maturity in enhancing the inhibition effect of compost on the plant pathogen P. cinnamomi. A further objective was to generate an increased understanding of the mechanism of growth inhibition

Erratum: What is the source? Identifying the cause of septic shock in a patient (Annals of the American Thoracic Society (2020) 17 (236-239) DOI: 10.1513/AnnalsATS.201907-562CC)

Copyright © 2020 by the American Thoracic Society. The authors would like to correct the author order in their article published in the February 2020 issue of AnnalsATS (1). The correct author order should be as follows: Nimrita Sidhu, Noor Ul-Ain Baloch, and Yonatan Greenstein. For the convenience of our readers, AnnalsATS is replacing the online version of the article with a corrected version; we apologize for the error

A multimedia visualization tool for solving mechanics dynamics problem

The objective of this research is to complement and enhanced traditional tutorial teaching and learning by incorporating multimedia technology. In this case study, the development of a PC base virtual experiment for mechanics dynamics problem involving the motion of a projectile that is taught in the second year of the mechanical engineering undergraduate course at University Tenaga Nasional (UNITEN) is described. The developed prototype tool was found to be effective in promoting learning and the outcome of this research revealed that multimedia approach enhanced user understanding of the underlying theory of engineering mechanics, promote interactivity as well as visualization and users are able to solve engineering problem such as motion of a projectile quickly and efficiently.The objective of this research is to complement and enhanced traditional tutorial teaching and learning by incorporating multimedia technology. In this case study, the development of a PC base virtual experiment for mechanics dynamics problem involving the motion of a projectile that is taught in the second year of the mechanical engineering undergraduate course at University Tenaga Nasional (UNITEN) is described. The developed prototype tool was found to be effective in promoting learning and the outcome of this research revealed that multimedia approach enhanced user understanding of the underlying theory of engineering mechanics, promote interactivity as well as visualization and users are able to solve engineering problem such as motion of a projectile quickly and efficiently

Arenibacter amylolyticus sp. nov., an amylase- producing bacterium of the family Flavobacteriaceae isolated from marine water in India

A novel Gram- stain- negative, curved rod- shaped, 0.5?0.7 ?m wide and 3.0?10.0 ?m long, non- motile bacterium, designated strain AK53T, was isolated from a 5 m depth water sample collected from the Bay of Bengal, Visakhapatnam, India. Colonies on marine agar were circular, small, dark orange, shiny, smooth, translucent, flat, with an entire margin. The major fatty acids included iso-C15:0, iso-C15: 0 3OH, anteiso- C15:0, iso-C15: 1 G, iso- C17: 0 3OH and summed feature 3 (C16:1 ?7c and/or C16:1 ?6c and/or iso-C15:0- 2OH). Polar lipids included phosphatidylethanolamine and five unidentified lipids. The DNA G+C content of the strain AK53T was found to be 40.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain AK53T was closely related to Arenibacter latericius KMM 426T and Arenibacter certesii KMM3941T (pair- wise sequence similarity of 99.17 and 98.89 %, respectively), forming a distinct branch within the genus Arenibacter and clustering with A. latericius. Strain AK53T shared average nucleotide identity (ANIb, based on BLAST) of 78.07 and 77.44 % with A. latericius JCM 13508T and A. certesii JCM 13507T, respectively. Based on the observed phenotypic, chemotaxonomic characteristics and phylogenetic analysis, strain AK53T is described in this study as representing a novel species in the genus Arenibacter, for which the name Arenibacter amylolyticus sp. nov. is proposed. The type strain of Arenibacter amylolyticus is AK53T (=MTCC 12004T= JCM 19206T=KCTC 62553T)

A two-species predator-prey model in an environment enriched by a biotic resource

Classical population growth models assume that the environmental carrying capacity is a fixed parameter, which is not often realistic. We propose a modified predator-prey model where the carrying capacity of the environment is dependent on the availability of a biotic resource. In this model both populations are able to consume the resource, thus altering the environment. Stability, bifurcation and numerical analyses are presented to illustrate the system's dynamical behaviour. Bistability occurs in certain parameter regions. This could describe the transition from a beneficial environment to a detrimental one. We examine special cases of the system and show that both permanence and extinction are possible. References J. Vandermeer. Seasonal isochronic forcing of Lotka Volterra equations. Prog. Theor. Phys., 96:13–28, 1996. doi:10.1143/PTP.96.13 S. Ikeda and T. Yokoi. Fish population dynamics under nutrient enrichment–-A case of the East Seto Inland Sea. Ecol. Model., 10:141–165, 1980. doi:10.1016/0304-3800(80)90057-5 S. P. Rogovchenko and Y. V. Rogovchenko. Effect of periodic environmental fluctuations on the Pearl–Verhulst model. Chaos, Solitons, Fractals, 39:1169–1181, 2009. doi:10.1016/j.chaos.2007.11.002 H. Safuan, I. N. Towers, Z. Jovanoski and H. S. Sidhu. A simple model for the total microbial biomass under occlusion of healthy human skin. In Chan, F., Marinova, D. and Anderssen, R.S. (eds) MODSIM2011, 19th International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand., 733–739, 2011. http://www.mssanz.org.au/modsim2011/AA/safuan.pdf P. Meyer and J. H. Ausubel. Carrying capacity: A model with logistically varying limits. Technol. Forecast. Soc., 61:209–214, 1999. doi:10.1016/S0040-1625(99)00022-0 R. Huzimura and T. Matsuyama. A mathematical model with a modified logistic approach for singly peaked population processes. Theor. Popul. Biol., 56:301–306, 1999. doi:10.1006/tpbi.1999.1426 J. H. M. Thornley and J. France. An open-ended logistic-based growth function. Ecol. Model., 184:257–261, 2005. doi:10.1016/j.ecolmodel.2004.10.007 J. H. M. Thornley, J. J. Shepherd and J. France. An open-ended logistic-based growth function: Analytical solutions and the power-law logistic model. Ecol. Model., 204:531–534, 2007. doi:10.1016/j.ecolmodel.2006.12.026 H. M. Safuan, I. N. Towers, Z. Jovanoski and H. S. Sidhu. Coupled logistic carrying capacity model. ANZIAM J, 53:C172–C184, 2012. http://journal.austms.org.au/ojs/index.php/ANZIAMJ/article/view/4972 P. H. Leslie and J. C. Gower. The properties of a stochastic model for the predator-prey type of interaction between two species. Biometrika, 47:219–234, 1960. doi:10.1093/biomet/47.3-4.219 B. Basener and D. S. Ross. Booming and crashing populations and Easter Island. SIAM J. Appl. Math., 65:684–701, 2005. doi:10.1137/S0036139903426952 D. Lacitignola and C. Tebaldi. Symmetry breaking effects on equilibria and time dependent regimes in adaptive Lotka–Volterra systems. Int. J. Bifurcat. Chaos, 13:375–392, 2003. doi:10.1142/S0218127403006595 F. Wang and G. Pang. Chaos and Hopf bifurcation of a hybrid ratio-dependent three species food chain. Chaos, Solitons, Fractals, 36:1366–1376, 2008. doi:10.1016/j.chaos.2006.09.005 R. Ball. Understanding critical behaviour through visualization: A walk around the pitchfork. Comput. Phys. Commun., 142:71–75, 2001. doi:10.1016/S0010-4655(01)00322-8 B. Ermentrout. XPP-Aut v. 6.00, 2011. http://www.math.pitt.edu/ bard/xpp/xpp.html R. Malka, E. Shochat and V. R. Kedar. Bistability and bacterial infections. PLOS ONE, 5:1–10, 2010. doi:10.1371/journal.pone.0010010 J. Elf, K. Nilsson, T. Tenson and M. Ehrenberg. Bistable bacterial growth rate in response to antibiotics with low membrane permeability. Phys. Rev. Lett., 97:258104, 2006. doi:10.1103/PhysRevLett.97.258104 D. Dubnau and R. Losick. Bistability in bacteria. Mol. Microbiol., 61:564–572, 2006. doi:10.1111/j.1365-2958.2006.05249.x M. Santillan. Bistable behavior in a model of the lac Operon in Escherichia coli with variable growth rate. Biophys. J., 94:2065–2081, 2008. doi:10.1529/biophysj.107.118026 M. Rosenzweig. Paradox of enrichment: destabilization of exploitation ecosystem in ecological time. Science, 171:385–387, 1971. doi:10.1126/science.171.3969.38

The thermal ignition problem in a cube

Steady state solutions for spontaneous thermal ignition in a unit cube are considered. For the unit sphere there are numerous solutions possible: these appear as ``wiggles'' in the bifurcation diagram. For the unit sphere this has been shown analytically. In contrast, for the unit cube analytic solutions are not possible and hence we must resort to numerical methods to determine the corresponding bifurcation diagram. Comparisons between the cube and the sphere are made

Combustion waves in a model with chain branching reaction and their stability

In this paper the travelling wave solutions in the adiabatic model with two-step chain branching reaction mechanism are investigated both numerically and analytically in the limit of equal diffusivity of reactant, radicals and heat. The properties of these solutions and their stability are investigated in detail. The behaviour of combustion waves are demonstrated to have similarities with the properties of nonadiabatic one-step combustion waves in that there is a residual amount of fuel left behind the travelling waves and the solutions can exhibit extinction. The difference between the nonadiabatic one-step and adiabatic two-step models is found in the behaviour of the combustion waves near the extinction condition. It is shown that the flame velocity drops down to zero and a standing combustion wave is formed as the extinction condition is reached. Prospects of further work are also discussed.Comment: pages 32, figures 2

Towards the probabilistic analysis of small bowel capsule endoscopy features to predict severity of duodenal histology in patients with villous atrophy

Small bowel capsule endoscopy (SBCE) can be complementary to histological assessment of celiac disease (CD) and serology negative villous atrophy (SNVA). Determining the severity of disease on SBCE using statistical machine learning methods can be useful in the follow up of patients. SBCE can play an additional role in differentiating between CD and SNVA. De-identified SBCEs of patients with CD and SNVA were included. Probabilistic analysis of features on SBCE were used to predict severity of duodenal histology and to distinguish between CD and SNVA. Patients with higher Marsh scores were more likely to have a positive SBCE and a continuous distribution of macroscopic features of disease than those with lower Marsh scores. The same pattern was also true for patients with CD when compared to patients with SNVA. The validation accuracy when predicting the severity of Marsh scores and when distinguishing between CD and SNVA was 69.1% in both cases. When the proportions of each SBCE class group within the dataset were included in the classification model, to distinguish between the two pathologies, the validation accuracy increased to 75.3%. The findings of this work suggest that by using features of CD and SNVA on SBCE, predictions can be made of the type of pathology and the severity of disease