Microalgal blooms in the coastal waters of New South Wales, Australia

We investigated the frequency and causative taxa of observed microalgal blooms in New South Wales (NSW) coastal waters from 2000 to 2009 and compared these to an earlier bloom inventory from 1990 to 1999. The majority of recurrent blooms are harmless water discolourations caused by Noctiluca scintillans and Trichodesmium erythraeum. The recent reporting period witnessed the first blooms of Astrionellopsis glacialis, Guinardia sp., Skeletonema sp., cf. Heterocapsa sp., Dinophysis caudata, Prorocentrum dentatum, Prorocentrum rhathymum, Fibrocapsa japonica, Gymnodinium catenatum, Oscillaroria sp., and Anabaena circinalis. The frequency of blooms appears to have increased over time with a shift in maximum bloom activity from January (1990 to 1999) to October (2000 to 2009). Peak bloom years correspond with El Niño episodes, the most significant being 1997 to 1998 and 2002 to 2003. No significant difference was found between the causative species or spatial distribution of dominant taxa over two decades. Differences were observed in bloom type in estuaries with more 'potentially harmful to marine organisms' blooms during 1990 to 1999 and more 'harmless' blooms during 2000 to 2009. More 'unidentified' blooms were reported during 2000 to 2009 compared to 1990 to 1999, for both marine and estuarine waters. We emphasize that although algal bloom reports are ad hoc in their nature, they can contribute valuable baseline information, which may suggest causative relationships for evaluating trends in phytoplankton ecology

Erratum: A decadal decline in relative abundance and a shift in microphytoplankton composition at a long-term coastal station off southeast Australia

In this study, we examined 11 yr (1998-2009) of water samples collected from Port Hacking coastal monitoring station 8 km offshore from Sydney, Australia, to assess changes in the microphytoplankton in relation to climate-related trends in environmental variables. A total of 152 taxa (85 genera) were identified, with the small diatom Thalassiosira cf. partheneia and the tropical cyanobacterium Trichodesmium erythraeum being the dominant species over the past decade. Taxon richness showed a distinct seasonal pattern, peaking in the austral winter. Ordination analyses revealed significant seasonal and interannual trends in species composition, including a decadal decline in dinoflagellates relative to diatoms toward the present. This decadal shift in taxonomic composition was, in turn, significantly associated with declines in water temperatures over this time period. Total abundance varied by 12 orders of magnitude (8.5 X 10⁻⁸ to 7.4 X 10⁴ cells L⁻¹), with values separable into bloom and nonbloom regimes at an abundance threshold of 7.1 X 10⁻⁵ cells L⁻¹. Significant temporal declines in abundance were observed during both bloom and nonbloom regimes. Blooms occurred most consistently in March, September, and December.13 page(s

Exploration of the Chemistry and Biological Properties of Pyrimidine as a Privilege Pharmacophore in Therapeutics

The pyrimidine moiety is one of the most widespread heterocycles in biologically occurring compounds, such as nucleic acids components (uracil, thymine and cytosine) and vitamin B1. Due to its prebiotic nature to living cells in biodiversity, it is an highly privileged motif for the development of molecules of biological and pharmaceutical interest. This present work deals with the exploration of chemistry and medicinal diversity of pyrimidine which might pave way to long await discovery in therapeutic medicine for future drug design

Geoimaging of subsurface fabric in Awgbagba, Southwestern Nigeria using geomagnetic and geoelectrical techniques

The heterogeneous nature of the earth has given rise to variations experienced in the subsurface. Some parts are good for hydrological exploration while others are good for civil engineering activities. These variations experienced in the subsurface could not be detected except through geophysical survey and analysis. Integration of ground magnetic and Vertical Electrical Sounding (VES) techniques were carried out in Awgbagba to image the subsurface fabric with a view to mapping subsurface geological features, such as the weak and competent zones, to determine the overburden thickness, and suitability of Awgbagba for civil engineering and hydrogeological purposes. Ten ground magnetic traverses were established in W-E and N-S azimuths. Twenty VES points were randomly sounded for the study in order to cover the entire study area. The magnetic residual field anomaly values ranged from -1, 600 to 700 nT. The study area is grouped into low, average, and high magnetic zones. The depth to magnetic sources ranged from 8.1 to 48.9 m with a mean value of 17.4 m. Three planar feature orientations in the study area are in NE-SW, NW-SE, and SE-NW orientations. VES results showed 7 QH-curve type, 6 HA-curve type, 4 KH-curve type, 1 AA-curve type, 1 HK-curve type and 1 QQ-curve type respectively. The ratio of thin-to-thick overburden and fresh-to-fractured bedrock are 3:7 and 2:3 respectively. It is concluded that the study area cannot withstand high-rise building constructions. However, the mapped fracture zones in the study area would serve as promising zones for borehole development

The microbiome of the cosmopolitan diatom leptocylindrus reveals significant spatial and temporal variability

Copyright © 2018 Ajani, Kahlke, Siboni, Carney, Murray and Seymour. The ecological interactions between phytoplankton and marine bacteria have important implications for the productivity and biogeochemistry of ocean ecosystems. In this study we characterized the microbial assemblages associated with multiple isolates of the ecologically important diatom Leptocylindrus using amplicon sequencing of the 16S rRNA gene, to examine levels of conservation of the microbiome across closely related species or strains. We also assessed if the microbiome structure of a given diatom strain was dependent on the location from which it was isolated and if the microbiome of cultured isolates significantly changed overtime from the seawater in which they were isolated. The bacterial assemblages from 36 strains belonging to three species (Leptocylindrus danicus, Leptocylindrus convexus, and Leptocylindrus aporus) isolated from six locations spanning > 1000 km of south east Australian coastline over 1 year, were dominated by the Rhodobacteraceae (∼60%) and the Flavobacteriaceae (∼10%). Across all strains, only one 'core OTU' (Roseovarius sp.) was identified across all samples. We observed no significant differences in bacterial community composition between diatom species. Significant differences in microbiome structure were, however, observed between diatom strains collected at different sampling times and from differing locations, albeit these two factors were coupled. Moreover, while bacterial communities under domestication varied from the seawater in which they were isolated, they remained specific to the location/month of origin, i.e., different regions and time points harbored distinct bacterial communities. Our study delivers new knowledge in relation to diatom-bacterial associations, revealing that the location/time from which a diatom is isolated plays an important role in shaping its microbiome

Dietary Fortification of Sorghum-Ogi using Crayfish (Paranephrops planifrons) as Supplements in Infancy

Malnutrition in neonates is a concern in developing countries where there is deficiency in nourishing foods for young ones. The utilization of fresh crayfish (Paranephrops planifrons) in enhancing the nutrient value of commonly used sorghum grain weaning food for infancy was investigated. The study was carried out using a 10 – 50 wt% mixture of sorghum grain and crayfish in three categories of soaked sorghum grains with unroasted crayfish (Case A); de-hulled roasted sorghum grains with roasted crayfish (Case B) and de-hulled, un-roasted sorghum grain with un-roasted crayfish (Case C). The proximate analysis, functional and pasting properties in addition to taste panel evaluation of the batch composition were determined. The result indicated beneficial fat and protein contents of the blend with increase addition of crayfish with Case B and Case C preferred. The overall acceptability at 5% confidence level of organoleptic evaluation identified Case B with over 70% acceptance value, while the amylograph pasting analysis indicated that crayfish blend improved the stability of sorghum-ogi, hence it is beneficial as weaning food for infancy

Heterogeneous Catalytic Efficiency of Silica Sulfuric Acid towards the Synthesis of Substituted Pyrimidin-2 (1H)-One Derivatives

Pyrimidine template is a highly privileged motif for the development of molecules of biological and pharmaceutical interest due to its prebiotic nature to life. This present study deals with the synthesis of pyrimidin- 2(1H)-one derivative from chalcones by the action of silica supported sulfuric acid (SSA) or conventional refluxed in concentrated hydrochloric acid. The chemical structures were confirmed by analytical data and spectroscopic means such as UV, IR, mass spectra, 1H and 13C NMR. SSA was found to be efficient method for the quantitative transformation to pyrimidine frame work. It can be re-used after simple washing with chloroform thereby rendering this procedure more economical

Comparative Study of Microwave-assisted and Conventional Synthesis of 3-[1-(s-phenylimino) Ethyl]-2H-chromen-2-ones and Selected Hydrazone Derivatives

In this study, 3-acetylcoumarin 1, used as the essential precursor was synthesized by the reaction of salicyaldehyde with ethyl acetoacetate in the presence of a catalytic amount of piperidine in solvent-free medium. Schiff bases 2-9 were obtained by the condensation reaction of 3-acetylcoumarin, 1 with various aniline derivatives while reaction of 3-hydrazinoquinoxalin-2-one with four different 6-susbtituted 3-acetylcoumarins afforded the corresponding hydrazones 10-13. Both Schiff bases and hydrazone products were synthesized under microwave irradiation method and conventional synthetic strategy for comparative study. The microwave assisted reaction was remarkably successful and gave both Schiff bases and hydrazones in higher yields at shorter reaction time compared to conventional heating method. The characterization of the synthesized compounds were structurally confirmed by analytical data as well as spectroscopic means which involved 1H-and 13C-nmr, ir, UV-visible and mass spectra