Effect of salt and temperature stresses on survival and infectivity of Heterorhabditis spp. IJs

Abstract Heterorhabditis is frequently found in coastal sandy soils where it may experience both high salinity and high temperatures. We tested the ability of infective juveniles (IJs) of three taxonomic groups of Heterorhabditis to infect insects in saline sand. We also tested whether salinity (sea water) affected the IJs' ability to tolerate elevated temperatures in aqueous suspension and in sand. IJs of all three taxonomic groups killed Galleria mellonella in saline sand (25.6% insects killed), but at a lower level than in non-saline sand (96.5% insects killed). Exposure of IJs in sand to high temperature reduced their ability to kill G. mellonella at 20 degrees C; heating IJs in saline sand reduced G. mellonella mortality to a lesser extent (25.6% at 20 degrees C, 18.3% at 39 degrees C) than heating in non-saline sand (96.5% at 20 degrees C, 17.5% at 39 degrees C). In aqueous suspension, IJs of the North-West European and Irish types of Heterorhabditis tolerated high temperature better in sea water (at least 95% survived 1 h at 39 C) than in distilled water (none survived 1 h at 38 degrees C). H. bacteriophora was more temperature tolerant: survival and subsequent infectivity of IJs was unaffected by temperature up to 39 degrees C in either medium. It was concluded that high salinity (sea water) reduces the ability of Heterorhabditis IJs to infect, but improves their tolerance of high temperature. Effets des chocs dus a la salinite et a la temperature sur la survie et l'infestivite des juveniles infestants d' Heterorhabditis spp. - Les Heterorhabditis sont frequemment rencontres dans les sols sableux cotiers ou ils peuvent etre soumis a des salinites et des temperatures elevees. Nous avons teste la capacite des juveniles infestants (IJs) de trois groupes taxinomiques d'Heterorhabditis a infester des insectes dans du sable sale. Nous avons aussi cherche a savoir si la salinite (eau de mer) affecte la capacite des IJs a tolerer des temperatures elevees, soit en suspension aqueuse, soit dans du sable. Les IJs des trois troupes taxinomiques tuent les Galleria mellonella dans le sable sale, mais a un taux plus faible que dans le sable non sale (25,6 contre 96,5% des insectes tues). L'exposition des IJs dans du sable a des temperatures elevees reduit leur capacite a tuer G. mellonella a 20 degrees C; le chauffage des IJs dans du sable sale reduit la mortalite des G. mellonella dans un moindre mesure (25,6 a 20 degrees C contre 18,3% a 39 degrees C) que dans du sable non sale (96,5% a 20 degrees C contre 17,5% a 39 degrees C). En suspension aqueuse, les IJs des types Europe du nord-ouest et d'Irlande tolerent mieux les temperatures elevees dans l'eau de mer (au moins 95% survivent 1 h a 39 degrees C) que dans l'eau distillee (aucune survie apres 1 h a 38 degrees C). H. bacteriophora montre la meilleure tolerance a la temperature: la survie et l'infestivite ulterieures des IJs ne sont pas affectees par la temperature jusqu'a 39 degrees C dans l'un et l'autre milieux. Il en est conclu que les salinites elevees (eau de mer) reduisent la capacite d'infestation des IJs d'Heterorhabditis, mais ameliorent leur tolerance aux temperatures elevees.

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Modification of Xanthan Gum for a High-Temperature and High-Salinity Reservoir

Polymers ◽

10.3390/polym13234212 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4212

Author(s):

Mohamed Said ◽

Bashirul Haq ◽

Dhafer Al Shehri ◽

Mohammad Mizanur Rahman ◽

Nasiru Salahu Muhammed ◽

...

Keyword(s):

High Temperature ◽

Oil Recovery ◽

Xanthan Gum ◽

Elevated Temperatures ◽

High Salinity ◽

Residual Oil ◽

Core Flooding ◽

Nacl Solution ◽

The Core ◽

Tertiary Oil Recovery

Tertiary oil recovery, commonly known as enhanced oil recovery (EOR), is performed when secondary recovery is no longer economically viable. Polymer flooding is one of the EOR methods that improves the viscosity of injected water and boosts oil recovery. Xanthan gum is a relatively cheap biopolymer and is suitable for oil recovery at limited temperatures and salinities. This work aims to modify xanthan gum to improve its viscosity for high-temperature and high-salinity reservoirs. The xanthan gum was reacted with acrylic acid in the presence of a catalyst in order to form xanthan acrylate. The chemical structure of the xanthan acrylate was verified by FT-IR and NMR analysis. The discovery hybrid rheometer (DHR) confirmed that the viscosity of the modified xanthan gum was improved at elevated temperatures, which was reflected in the core flood experiment. Two core flooding experiments were conducted using six-inch sandstone core plugs and Arabian light crude oil. The first formulation—the xanthan gum with 3% NaCl solution—recovered 14% of the residual oil from the core. In contrast, the modified xanthan gum with 3% NaCl solution recovered about 19% of the residual oil, which was 5% higher than the original xanthan gum. The xanthan gum acrylate is therefore more effective at boosting tertiary oil recovery in the sandstone core.

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A survey of entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae (Nematoda: Rhabditida) in the north-west of Iran

Nematology ◽

10.1163/156854108x398453 ◽

2009 ◽

Vol 11 (1) ◽

pp. 107-116 ◽

Cited By ~ 23

Author(s):

Naser Eivazian Kary ◽

Gholamreza Niknam ◽

Seyed Abolgasem Mohammadi ◽

Christine Griffin ◽

Mohammad Moghaddam

Keyword(s):

Entomopathogenic Nematodes ◽

Galleria Mellonella ◽

Heterorhabditis Bacteriophora ◽

Common Species ◽

Soil Samples ◽

Steinernema Carpocapsae ◽

Steinernema Feltiae ◽

North West ◽

The North ◽

First Time

AbstractDuring 2002-2004, a survey of entomopathogenic nematodes was conducted for the first time in Iran throughout the three provinces in the north-west of the country. Soil samples were tested for the presence of steinernematid and heterorhabditid nematodes by baiting with Galleria mellonella larvae. Of the 833 soil samples studied 27 were positive for entomopathogenic nematodes (3.2%), with 17 (2.0%) containing Heterorhabditis and ten (1.2%) Steinernema isolates. Morphological and molecular studies were carried out to characterise isolates. The Heterorhabditis isolates were identified as Heterorhabditis bacteriophora and Steinernema as Steinernema carpocapsae, S. bicornutum and S. feltiae. Heterorhabditis bacteriophora was the most common species, which was isolated from 17 sites across the three provinces. Steinernema feltiae was the most common species of Steinernema, which was isolated from eight sites but in only two provinces. Steinernema carpocapsae and S. bicornutum were each isolated from only one site. Steinernema spp. were isolated mainly from orchards and grasslands but Heterorhabditis was isolated mainly from grasslands and alfalfa fields.

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Considérations physiques sur le passage Nord-ouest; by the same. Communicated by the Right Hon. the Earl of Minto, G. C. B. F. R. S

Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London ◽

10.1098/rspl.1830.0300 ◽

1837 ◽

Vol 3 ◽

pp. 484-484

Keyword(s):

Sea Water ◽

Freezing Point ◽

Atmospheric Temperature ◽

North West ◽

The North ◽

The Mean ◽

Coppermine River ◽

The Right ◽

North Latitude

The author of this memoir, considering that the practicability of a North-west Arctic passage must depend on the mean summer atmospheric temperature of the most northern point of the continent of America being above that at which the congelation of sea water takes place, applies himself to the determination of these temperatures. The results of his calculations are given in a table, exhibiting the extreme and the mean temperatures of the atmosphere for each of the summer months, from May to September, at all degrees of latitude, from 60° to 80° inclusive. According to this table, the temperature of zero, which is about the freezing point of sea water, prevails, at 60° of latitude, on the 10th of May; at 61° lat. on the 20th of May; at 63°, on the 1 st of June; at 65°, on the 10th of June; at 67°, on the 20th of June; and at 71°, during the whole of the months of July and August. The author concludes that navigators can reach, without danger of being obstructed by ice, the latitude of 71° during these latter months: and that since the American continent does not probably extend beyond 70° north latitude a passage to the North-west is then open. He recommends, however, that instead of attempting it by the dangerous navigation of the polar sea, a coasting voyage between the continent and the numerous islands which exist in that ocean should be undertaken; or, what he thinks still more promising of success, an expedition by land for exploring the country intervening between the Coppermine River and Hudson’s Bay.

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XVIII.—Recent Oceanographical Investigations in the Faroe-Shetland Channel

Proceedings of the Royal Society of Edinburgh Section A Mathematical and Physical Sciences ◽

10.1017/s0080454100007500 ◽

1957 ◽

Vol 64 (3) ◽

pp. 239-289 ◽

Cited By ~ 1

Author(s):

John B. Tait

Keyword(s):

Cross Sections ◽

Large Scale ◽

Water Mass ◽

Sea Water ◽

Volume Transport ◽

Oceanic Water ◽

Arctic Water ◽

Norwegian Sea ◽

North West ◽

The North

SynopsisThe Faroe-Shetland Channel is the threshold from the north-eastern Atlantic Ocean to north-west European seas. Through it passes the main bulk of the oceanic water-mass which is the predominant influx, among several other water-masses, to these seas.The following research into the dynamics and general hydrography of the region is based on numerous observations of temperature and salinity, from surface to bottom, taken mainly on two vertical cross-sections of the Channel between the years 1927 and 1952 inclusive, excepting the war years 1940 to 1945.The research reveals very large scale seasonal and long-term variations in the northeastward volume-transport of oceanic water, suggests the existence on occasions of what appear to be horizontal tortional currents within the oceanic water-mass, and demonstrates (a) the intrusion of Gulf of Gibraltar (extra-Mediterranean) water into this mass over a period of years, (b) the formation of heavy oceanic water and (c) of a sub-oceanic watermass. The last-mentioned may sometimes almost entirely displace the bottom Norwegian Sea water-mass which normally underlies the oceanic mass.One or other, or both, of two types of Arctic water may also sometimes displace bottom Norwegian Sea water as the bottom water-mass of the region, the process, like that of the above-mentioned Gulf of Gibraltar water influx, waxing and waning over a term of years and thus exemplifying the phenomenon of marine climatic change.

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Loktanella agnita sp. nov. and Loktanella rosea sp. nov., from the north-west Pacific Ocean

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.63461-0 ◽

2005 ◽

Vol 55 (5) ◽

pp. 2203-2207 ◽

Cited By ~ 43

Author(s):

Elena P. Ivanova ◽

Natalia V. Zhukova ◽

Anatoly M. Lysenko ◽

Nataliya M. Gorshkova ◽

Alexander F. Sergeev ◽

...

Keyword(s):

Pacific Ocean ◽

Sea Water ◽

Sequence Similarity ◽

Carbon Sources ◽

Tween 80 ◽

Rrna Gene ◽

North West ◽

Temperature Range ◽

West Pacific Ocean ◽

The North

One whitish and four pinkish strains of Gram-negative, non-motile, aerobic bacteria were isolated from sea-water and sediment samples collected in Chazhma Bay (Sea of Japan, Pacific Ocean). Analysis of 16S rRNA gene sequences revealed that these strains belonged to the ‘Alphaproteobacteria’, having highest sequence similarity of about 94–97 % with species of the genus Loktanella. None of the strains degraded gelatin, casein, chitin, agar, DNA or starch and they had limited ability to utilize carbon sources. The four pinkish strains, Fg36T, Fg1, Fg116 and Fg117, degraded Tween 80. Sea-water strain R10SW5T grew at 3–6 % NaCl and a temperature range of 8–35 °C, whilst strains Fg36T, Fg1, Fg116 and Fg117 grew at NaCl concentrations of 1–12 % and a temperature range of 4–35 °C. Phosphatidylglycerol (58/79 %), diphosphatidylglycerol (11/6 %) and phosphatidylcholine (28/22 %) were the major phospholipids. The predominant fatty acids were 16 : 0 (12·2/8·6 %) and 18 : 1ω7 (76·6/68·4 %). The DNA G+C content of strain R10SW5T was 59·1 mol% and those of the four pinkish strains ranged from 60·5 to 61·8 mol%. Based on the results of phenotypic, genotypic, chemotaxonomic and phylogenetic investigation, two novel species, Loktanella agnita sp. nov. and Loktanella rosea sp. nov., are proposed. The type strains are R10SW5T (=KMM 3788T=CIP 107883T) and Fg36T (=KMM 6003T=CIP 107851T=LMG 22534T), respectively.

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ON SOUND SCATTERING IN THE UPPER LAYER AND ON THE SHELF OF THE NORTH-WEST PACIFIC OCEAN

10.35976/poi.2020.57.50.001 ◽

2020 ◽

Author(s):

В.А. Буланов ◽

И.В. Корсков ◽

А.В. Стороженко

Keyword(s):

Pacific Ocean ◽

Marine Environment ◽

Sea Water ◽

Peter The Great Bay ◽

Sound Scattering ◽

West Pacific ◽

North West ◽

Scattering Coefficients ◽

West Pacific Ocean ◽

The North

Представлены результаты исследований рассеяния звука в верхнем слое морской воды в северо-западной части Тихого океана. Измерения коэффициентов рассеяния звука проводились на различных частотах от 12 до 100 кГц на шельфе и в открытом океане. Исследования представляли интерес в связи с возможностью оперативно в процессе движения судна проводить мониторинг изменчивости структуры морской среды. Проведение долговременных исследований рассеяния звука на планктоне и других микронеоднородностях морской среды в бухте Витязь залива Петра Великого Японского моря с применением акустических донных систем позволило определить вариации рассеяния звука, связанного с наличием пузырьков и суточных вариаций планктона в толще моря. Показаны возможности и проведены оценки биомассы вдоль длинных трасс в различных морях северо-западной части Тихого океана на основе рассеяния звука. The results of studies of sound scattering in the upper layer of sea water in the North-Western Pacific Ocean are presented. Sound scattering coefficients were measured at various frequencies from 12 to 100 kHz on the shelf and in the open ocean. The research was of interest because it was possible to monitor the variability of the marine environment structure quickly during the ship’s movement. Long-term studies of sound scattering on plankton and other micro-heterogeneities of the marine environment in Vityaz Bay, Peter the Great Bay, Sea of Japan, using acoustic bottom systems, allowed us to determine variations in sound scattering associated with the presence of bubbles and diurnal variations of plankton in the sea column. The possibilities of biomass along long trails in various seas of the North-West Pacific Ocean based on sound scattering are shown and estimated.

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Lighten up the dark: metazoan parasites as indicators for the ecology of Antarctic crocodile icefish (Channichthyidae) from the north-west Antarctic Peninsula

PeerJ ◽

10.7717/peerj.4638 ◽

2018 ◽

Vol 6 ◽

pp. e4638 ◽

Cited By ~ 3

Author(s):

Thomas Kuhn ◽

Vera M.A. Zizka ◽

Julian Münster ◽

Regina Klapper ◽

Simonetta Mattiucci ◽

...

Keyword(s):

Antarctic Peninsula ◽

South Shetland Island ◽

Stomach Contents ◽

Biological Indicators ◽

Parasite Fauna ◽

Metazoan Parasites ◽

North West ◽

The North ◽

West Antarctic ◽

Taxonomic Groups

Due to its remote and isolated location, Antarctica is home to a unique diversity of species. The harsh conditions have shaped a primarily highly adapted endemic fauna. This includes the notothenioid family Channichthyidae. Their exceptional physiological adaptations have made this family of icefish the focus of many studies. However, studies on their ecology, especially on their parasite fauna, are comparatively rare. Parasites, directly linked to the food chain, can function as biological indicators and provide valuable information on host ecology (e.g., trophic interactions) even in remote habitats with limited accessibility, such as the Southern Ocean. In the present study, channichthyid fish (Champsocephalus gunnari: n = 25, Chaenodraco wilsoni: n = 33, Neopagetopsis ionah: n = 3, Pagetopsis macropterus: n = 4, Pseudochaenichthys georgianus: n = 15) were collected off South Shetland Island, Elephant Island, and the tip of the Antarctic Peninsula (CCAML statistical subarea 48.1). The parasite fauna consisted of 14 genera and 15 species, belonging to the six taxonomic groups including Digenea (four species), Nematoda (four), Cestoda (two), Acanthocephala (one), Hirudinea (three), and Copepoda (one). The stomach contents were less diverse with only Crustacea (Euphausiacea, Amphipoda) recovered from all examined fishes. Overall, 15 new parasite-host records could be established, and possibly a undescribed genotype or even species might exist among the nematodes.

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Isolation and characterisation of Heterorhabditis spp. (Nematoda: Heterorhabditidae) from Hungary, Estonia and Denmark

Nematology ◽

10.1163/156854199508199 ◽

1999 ◽

Vol 1 (3) ◽

pp. 321-332 ◽

Cited By ~ 9

Author(s):

Christine T. Griffin ◽

Ilona Dix ◽

Susan A. Joyce ◽

Ann M. Burnell ◽

Martin J. Downes

Keyword(s):

Entomopathogenic Nematode ◽

Single Site ◽

North Coast ◽

First Report ◽

North West ◽

The North ◽

Taxonomic Groups ◽

West European

Abstract Targeted surveys were conducted for the entomopathogenic nematode Heterorhabditis in areas of Denmark, Estonia and Hungary. Isolates were identified by IEF, PCR and cross-fertility tests as belonging to three distinct taxonomic groups: H. bacteriophora, the north-west European (NWE) type of H. megidis and the Irish type of Heterorhabditis. The Irish and NWE types of Heterorhabditis were both present in Denmark (at six and four sites, respectively), while only the NWE type was recovered in Estonia. H. bacteriophora was the dominant heterorhabditid identified in Hungary (ten sites), but the Irish type was also detected at two sites. This is the first report of the Irish type of Heterorhabditis on continental Europe. Co-occurrence of two Heterorhabditis types at a single site was noted in Denmark (Irish and NWE) and in Hungary (Irish and H. bacteriophora). Heterorhabditis was recovered at 38.5% of sites (n = 26) in Denmark (north coast of Sjaelland), 27.3% of the coastal sites (n = 22) in Estonia, and 32.6% of sites (n = 46) in Hungary. Isolation et caracterisation d'especes d'Heterorhabditis (Nematoda: Heterorhabditidae) originaires de Hongrie, d'Estonie et du Danemark - Des prospections ciblees ont ete effectuees dans certaines regions du Danemark, d'Estonie et de Hongrie pour rechercher les nematodes du genre Heterorhabditis. Les souches, identifiees par les methodes de concentration isoelectrique, de PCR et d'hybridation, appartiennent aux trois groupes taxinomiques d'Heterorhabditis : H. bacteriophora, le groupe de l'Europe du nord-ouest (NWE) de H. megidis et le groupe irlandais d'Heterorhabditis. Le groupe irlandais et le groupe NWE sont tous les deux presents au Danemark (dans six et quatre sites, respectivement), mais seul le dernier groupe a ete rencontre en Estonie. H. bacteriophora, present dans dix sites, est l'espece dominante d'Heterorhabditis en Hongrie, mais le groupe irlandais a ete egalement detecte dans deux sites. C'est la premiere fois que le groupe irlandais est rencontre en Europe continentale. La presence simultanee de deux types d'Heterorhabditis est signalee au Danemark (groupe irlandais et groupe NWE) et en Hongrie (groupe irlandais et H. bacteriophora). Des Heterorhabditis ont ete collectes sur 38.5% des 26 sites du Danemark (cote nord de Sjaelland), 27.3% des 22 sites du littoral estonien et 32.6% des 46 sites de Hongrie.

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NEW AQUEOUS POLYMER FOR HIGH-TEMPERATURE RESERVOIRS

Periódico Tchê Química ◽

10.52571/ptq.v15.n30.2018.383_periodico30_pgs_380_386.pdf ◽

2018 ◽

Vol 15 (30) ◽

pp. 380-386

Author(s):

Y. V. SAVINYKH ◽

L. D. LANG

Keyword(s):

High Temperature ◽

Oil Recovery ◽

High Salinity ◽

Sea Water ◽

Polymer Flooding ◽

Water Soluble ◽

Water Flooding ◽

Polymer Gel ◽

Sweep Efficiency ◽

Water Soluble Polymer

Polymer flooding is technologically simple and highly effective method of enhanced oil recovery. The method is based on adding a small amount of polymer in conventional water flooding of oil reservoirs. The increase in viscosity and the reduction of the mobility of injected water are to equalize the displacement front by slowing the moving of water in the highly permeable zones and restricting the formation of water finger. These factors help to increase the sweep efficiency and oil-water displacement efficiency during flooding. Polymer flooding has been used successfully in clastic and carbonate reservoirs, as well as in low-permeability reservoirs such as a fractured basement. However, most of the current polymer gel used for control water flows are decayed by a high content of ions Ca2+ and Mg2+ in formation water or in injected water. Similarly, polymer gels lose their stability at high reservoir temperature (above 70°C). Developing water-soluble polymer, which does not change their rheological properties under high salinity and high temperature (over 100°C), is very important when producing offshore, where sea water is commonly used for flooding (high salinity of 30-40 g/L).

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