An Updated Review of Tetrodotoxin and Its Peculiarities

Tetrodotoxin (TTX) is a crystalline, weakly basic, colorless organic substance and is one of the most potent marine toxins known. Although TTX was first isolated from pufferfish, it has been found in numerous other marine organisms and a few terrestrial species. Moreover, tetrodotoxication is still an important health problem today, as TTX has no known antidote. TTX poisonings were most commonly reported from Japan, Thailand, and China, but today the risk of TTX poisoning is spreading around the world. Recent studies have shown that TTX-containing fish are being found in other regions of the Pacific and in the Indian Ocean, as well as the Mediterranean Sea. This review aims to summarize pertinent information available to date on the structure, origin, distribution, mechanism of action of TTX and analytical methods used for the detection of TTX, as well as on TTX-containing organisms, symptoms of TTX poisoning, and incidence worldwide.

Estimating organic carbon in soils from Gulyantsi Municipality, Pleven District

The aim of the present study is to evaluate soil organic carbon in Gulyantsi Municipality, Pleven District. The case study area of “Ulpia Eskus” Reserve was chosen for the research. The composition of soil organic substance of Arenosols + Fluvisols is distinguished by the use of a chemical analysis and the application of the Turin method. The results show a prevalence of humic acids over fulvic acids in the sampled soil profile. Keywords: soil organic carbon, soil horizons, excavations.

SST Image Processing for Mesoscale Patterns Identification

Understanding the marine environment dynamics to accordingly design computational predictive tools, represents a factor of paramount relevance to implement suitable policy plans. In this framework, mesoscale marine events are important to study and understand since human related activities, such as commercial fishery, strongly depend on this type of phenomena. Indeed, the dynamics of water masses affect the local habitats due to nutrient and organic substance transport, interfering with the fauna and flora development processes. Mesoscale events can be classified based on the presence of specific hydrodynamics features, such as water filaments, counter-currents or meanders originating from upwelling wind action stress. In this paper, a novel method to study these phenomena is proposed, based on the analysis of Sea Surface Temperature imagery captured by satellite missions (METOP, MODIS Terra/Aqua). Dedicated algorithms are presented, with the goal to detect and identify different observed scenarios based on the extraction and analysis of discriminating quantitative features. Promising results returned by the application of the proposed method to data captured within the maritime region in front of the southwestern Iberian coasts are presented.

Technical evaluation of ultrafiltration unit in Siwalanpaji’s water treatment plant, PDAM Sidoarjo

Raw water with high turbidity requires pretreatment on its ultrafiltration unit to prevent fouling. Based on that, it is necessary to evaluate the ultrafiltration unit’s quality, quantity, and operation in Siwalanpanji’s WTP. The evaluation method compares the design criteria, technical specification, and ultrafiltration with the conventional to see the existing condition. The results of ultrafiltration turbidity and organic substance efficiency removal are about 53% and 18%, it’s not more good than conventional unit efficiency removal, which has 89% for turbidities removal and 37% for organic substance removal. Moreover, the quality of the production water fulfils the standards of Indonesia Health Minister No. 492 of 2010, except for the value of organic substances, which is in this analysis it around 13.69 mg/L meanwhile, in standard, it must not be more than 10 mg/L. Evaluation of the operating performance of each treatment unit related to the membrane unit at the WTP in Siwalanpanji has fulfilled the criteria design. However, using an ultrafiltration unit results in treated water quality is equivalent to a conventional treatment unit. So from this evaluation, it is found that there is a need for recommendations pretreatment, which is better for raw water to treat before ultrafiltration.

ORGANIC SUBSTANCE IN THE SOILS OF TRANSPORTATION AND RECREATION ZONES OF YAKUTSK

The content of organic matter in the Yakutsk city soils of the recreational zones (squares, park of culture and rest, floodplain meadow) and transport zones (lawns along major transport routes) was studied. It is shown that the urban soils of Yakutsk under green spaces are characterized by low potential fertility. They are poor in humus and are moderately supplied with alkaline hydrolysable nitrogen.

30 years of IRMM-1027 reference materials for fissile material accountancy and control: development, production and characterisation

The IRMM-1027 Large-sized dried (LSD) spikes are certified reference materials applied to measure the uranium and plutonium content of dissolved fuel solutions using isotope dilution mass spectrometry. High quality starting metals of uranium and plutonium are dissolved to produce a stock solution, which is dispensed into individual vials and dried down. The present spikes are mixtures of typically 50 mg 20% enriched U and 2 mg enriched 239Pu as dried nitrates, conditioned in an organic substance for stability. Each vial of an IRMM-1027 LSD spike comes with certified masses of uranium (235U and 238U) and 239Pu and isotopic composition with associated uncertainty. This article will discuss major developments since the production of the first batch of LSD spikes and will reflect on the current preparation and certification approaches.

An Evaluation of the Possible Uses of CNT in Flow Conditions for Removing Humic Substances from Water

This study concerns an evaluation of humic substance removal during an adsorption process on three sorbents: two consisting of carbon nanotubes embedded on a polymer (polypropylene and polyethylene) and granulated active carbon as a reference. The results that were obtained show a significantly lower organic substance removal effectiveness in the case of sorbents containing carbon nanotubes, with an insignificantly lower unit effectiveness (mg/g) of the nanosorbents during first two hours of adsorption. Unfortunately, nanosorbents only allow removing substances with a low molecular weight and high aromaticity, which significantly reduces the possibility of its use in technical conditions for naturally occurring water and the sorption capacity nanotubes were significantly lower in comparison to the GAC.

SIGNIFICANCE OF SOIL FERTILITY INDICATORS FOR MONITORING

The need to search for integral indicators of soil fertility for monitoring based on the control of the synthesis of total biomass (the organic substance underlying the law of soil fertility) and crop productivity using modern information (primarily unmanned technologies) is justified in order to obtain detailed information on soil fertility occupied by crops. At the same time, it is important to develop methods for monitoring the balance of organic matter of the soil, reflecting its mineralization, humification and other types of its transformation.