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The phreatic eruption is one of the volcanic eruption styles triggered by the rapid vaporization of heated fluids at shallow depth without the involvement of juvenile magma (e.g., Stix and deMoor [23]). 10.1186/s40623-021-01468-3 5 Kataoka KS, Tsunematsu K, Matsumoto T. Crisis hazard assessment for snow-related lahars from an unforeseen new vent eruption: the 2018 eruption of Kusatsu-Shirane volcano, Japan. Papers on the Kusatsu-Shirane volcano Kusatsu-Shirane volcano is an active dacite-andesite Quaternary volcano located in Gunma Prefecture, Central Japan. After the onset of the 2010 phreatic eruption of the Turrialba volcano, the underlying geothermal system changed as seen from the significant increase in the fumarole output at the Turrialba volcano. [Extracted from the article]

Direct sampling and analysis of fumarolic gas was conducted at Ebinokogen Ioyama volcano, Japan, between December 2015 and July 2020. Notable changes in the chemical composition of gases related to volcanic activity included a sharp increase in SO2 and H2 concentrations in May 2017 and March 2018. The analyses in March 2018 immediately preceded the April 2018 eruption at Ioyama volcano. The isotopic ratios of H2O in fumarolic gas revealed the process of formation. Up to 49% high-enthalpy magmatic vapor mixed with 51% of cold local meteoric water to generate coexisting vapor and liquid phases at 100–160 °C. Portions of the vapor and liquid phases were discharged as fumarolic gases and hot spring water, respectively. The CO2/SO2 ratio of the fumarolic gas was higher than that estimated for magmatic vapor due to SO2 hydrolysis during the formation of the vapor phase. When the flux of the magmatic vapor was high, effects of hydrolysis were small resulting in low CO2/SO2 ratios in fumarolic gases. The high apparent equilibrium temperature defined for reactions involving SO2, H2S, H2 and H2O, together with low CO2/SO2 and H2S /SO2 ratios were regarded to be precursor signals to the phreatic eruption at Ioyama volcano. The apparent equilibrium temperature increased rapidly in May 2017 and March 2018 suggesting an increased flux of magmatic vapor. Between September 2017 and January 2018, the apparent equilibrium temperature was low suggesting the suppression of magmatic vapor flux. During this period, magmatic eruptions took place at Shinmoedake volcano 5 km away from Ioyama volcano. We conclude that magma sealing and transport to Shinmoedake volcano occurred simultaneously in the magma chamber beneath Ioyama volcano. [ABSTRACT FROM AUTHOR]

Determination of H 2 S and SO 2 in fumarolic gases is necessary to predict volcanic activities. This study evaluated three gas sampling methods (CdS precipitation, Ag 2 S precipitation, and I 2 oxidation) using artificial fumarolic gases with known compositions. H 2 S was initially fixed as CdS(s) or Ag 2 S(s) in the sulfide precipitations and S(0) in the I 2 oxidation. On the other hand, SO 2 was collected as dissolved species (SO 3 2 − and SO 4 2 − ). The Ag 2 S precipitation, which did not allow HCl determination in fumarolic gases by forming AgCl(s), significantly underestimated H 2 S and SO 2 due to the entrained loss of analytes as a result of water vaporization during H 2 O 2 treatment. The I 2 oxidation, which required duplicate sampling for complete analysis of H 2 S and SO 2 , tended to overestimate SO 2 probably due to difficulties in separating S(0) particles from solutions. The CdS precipitation produced more satisfactory H 2 S and SO 2 recoveries than the other methods. Additionally, the effect of delayed sample treatment was assessed by comparing H 2 S-to-SO 2 molar ratios resulting from immediate and one-week-delayed treatments after gas collection. The delayed treatment significantly lowered the ratios in the CdS precipitation likely due to the susceptibility of CdS(s) to oxidation. In the meanwhile, such an effect was minimal in I 2 oxidation. Similar results were also observed in the field evaluation of fumarolic gases at Mt. Hakone. Along with detailed sampling and treatment procedures, the causes for unsatisfactory H 2 S and SO 2 recoveries were discussed in the context of the underlying reaction schemes as well as potential experimental artifacts. Thus, this study helps to select and further modify appropriate gas sampling methods to meet specific needs. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms involved in the formation of maars and their diatreme growth processes has been a subject of contention. While there is no direct evidence of the presence of diatremes beneath most of the young maars, their existence is inferred based on the amount and type of country rocks excavated at different depths and deposited as pyroclastic ejecta around their craters. Properly tracing fragmented country rocks in ejecta to interpret their depths of origin and thus the depths of phreatomagmatic explosions require good and detailed information on the substrate geology that is generally lacking at many maars. As an alternative, this paper explores the role of juvenile components in deposits of a maar for understanding the cratering and growth of diatremes during maar-forming eruptions. Based on field investigations, pyroclast distribution, componentry and grain morphology examinations this study reports on the eruptive mechanisms that led to the formation of the Barombi Mbo Maar (BMM), a polygenetic maar volcano in Cameroon. The BMM consists of three diatremes that formed during distinct eruptive events and coalesced to produce an “amalgamated maar–diatreme”. Two end-member types of eruption styles from the “dry” magmatic to the “wet” phreatomagmatic explosions governed the formation of the maar. In total, a minimum of ~ 0.0658 km 3 of magma (Dense Rock Equivalent corrected) was ejected based on calculation by applying interpolation techniques on digital elevation models obtained from SRTM30m data corrected by rock textural data collected from the field. The distribution of juvenile clasts throughout the stratigraphic sequence suggests a complex subsurface eruptive process, which originated probably within the uppermost part of the diatreme. From the distribution and morphology of juvenile clasts in the deposits, it is inferred that cratering and country rock excavation during the growth of each of the small diatremes developed mainly from shallow level explosions, sometimes with lateral and vertical variations in the position of the explosion loci. A prospective juvenile-based conceptual model is proposed for the formation of the BMM. The model suggests that, during maar-forming eruptions, explosions taking place at a deeper position might entrain extensive amount of lithics from the mostly lithic-dominated upper crater infill to deposit juvenile-poor (< 10 vol.%) tephra beds. Layers with a juvenile content of 10–60 vol.%, for example, might result from deep to shallow-seated explosions, with a common entrainment of lithics from the crater infill region, and with much of the remobilized tephra being transported to the ejecta ring sequence. In contrast, explosions occurring at shallower positions will produce mainly juvenile-rich beds (juvenile > 90 vol.%). [ABSTRACT FROM AUTHOR]

Rainwater characteristics can reveal emissions from various anthropogenic and natural sources into the atmosphere. The physico-chemical characteristics of 44 monthly rainfall events (collected between January and December 2012) from 4 weather stations (Bamenda, Ndop plain, Ndawara and Kumbo) in the Bamenda Highlands (BH) were investigated. The purpose was to determine the sources of chemical species, their seasonal inputs and suitability of the rainwater for drinking. The mean pH of 5 indicated the slightly acidic nature of the rainwater. Average total dissolved solids (TDS) were low (6.7 mg/L), characteristic of unpolluted atmospheric moisture/air. Major ion concentrations (mg/L) were low and in the order K + > Ca 2+ > Mg 2+ > Na + for cations and NO 3 −       ≫       HCO 3 −       >       SO 4 2 −       >       Cl −       >       PO 4 3 −       >       F − for anions. The average rainwater in the area was mixed Ca-Mg-SO 4 -Cl water type. The Cl – /Na + ratio (1.04) was comparable to that of seawater (1.16), an indication that Na + and Cl – originated mainly from marine (Atlantic Ocean) aerosols. High enrichments of Ca 2+ , Mg 2+ and SO 2– 4 to Na + ratios relative to seawater ratios (constituting 44% of the total ions) demonstrated their terrigenous origin, mainly from Saharan and Sahelian arid dusts. The K + /Na + ratio (2.24), which was similar to tropical vegetation ash (2.38), and NO 3 – was essentially from biomass burning. Light (< 100 mm) pre-monsoon and post-monsoon convective rains were enriched in major ions than the heavy (> 100 mm) monsoon rains, indicating a high contribution of major ions during the low convective showers. Despite the acidic nature, the TDS and major ion concentrations classified the rainwater as potable based on the WHO guidelines. [ABSTRACT FROM AUTHOR]

A classof dinuclear group 6 metal complexes [{M0(CO)5}2(μ-S,S′-EtL)] (M = Cr, Mo, W) with the asymmetrically bridged zwitterionicsulfur donor bis(N,N-diethylamino)carbeniumdithiocarboxylate(EtL) was prepared by photoreaction of [M0(CO)6] with EtL in hexane–CH2Cl2for Cr andMo or THF for W. The same structure in a syn–anticoordination mode was revealed by X-ray analyses forchromium(0) andtungsten(0) complexes, 1and 3, respectively, and speculated from various analyticaldata for the molybdenum(0) complex 2. The pertinent criteriafor the coordination mode are found to be the wavenumber of the asymmetricstretching vibration of the −CS2moiety in the solidstate and the ligand-based reduction potential in solution. Complexes 1and 3showed quasi-reversible reduction waves,which are assigned to a two-step, one-electron reduction process derivedfrom the bridging EtL. In a series of [Cr(CO)5L] complexes(L = monodentate ligand), the 13C NMR chemical shifts ofthe trans-to-L carbonyl group showed the order ofincreasing σ-donor/π-acceptor ratio of the ligands. Thesulfur donor ligands, including EtL and thione, are positioned inthe middle of this range. All complexes exhibited negative solvatochromism:the wavelength of the absorption maximum shifted to the blue sidein the range 500–600 nm with an increase in the Reichardt solventpolarity parameters ET(30), except forprotic solvents. Quantum chemical calculations by time-dependent densityfunctional theory–polarized continuum model were employed forunderstanding the excited states and solvatochromic properties ofcomplex 3. The calculated vertical excitation energiesin solution are consistent with the experimental data, suggestingthat the transition is a metal-to-ligand charge-transfer transition.In addition, UV–vis, NMR, and cyclic voltammetry data showedthat complex 3dissociates into two mononuclear speciesin polar solvents: [W(CO)5(EtL)] and [W(CO)5(solvent)]. [ABSTRACT FROM AUTHOR]

The chemical and isotopic compositions of volcanic gases at a borehole and a natural fumarole in the Owakudani geothermal area, Hakone volcano, Japan, have been repeatedly measured since 2001, when a seismic swarm occurred in the area. The CO/HO and CO/HS ratios were high in 2001. It increased in 2006 and again in 2008 when seismic swarms occurred beneath the geothermal area. The observed increases suggest the injection of CO- and SO-rich magmatic gas into the underlying hydrothermal reservoir, implying that the magmatic gas was episodically supplied to the hydrothermal system in 2006 and 2008. The earthquake swarms probably resulted from the injection of gas through the shallow crust accompanying the break of the sealing zone. [ABSTRACT FROM AUTHOR]

Abstract: Two distinctive magmatic fluids were recognized in the Tatun volcanic group (TVG), Taiwan. One is a relatively reduced fluid represented by the fumarolic gases at Hsiao-you-ken (HYK) geothermal field. Another is an oxidized fluid containing high concentrations of HCl represented by the fumarolic gases at Da-you-ken (DYK). An intermediate gas was recognized at Gung-tze-ping (GTP) and She-hung-ping (SHP). The fumarolic gases at HYK and GTP possess the features of so-called primary steam generated on mixing of magmatic gas and meteoric groundwater. The fumarolic gases at DYK are a simple mixture between magmatic gas and water vapor of meteoric origin. The CO2/H2O molar ratio of the magmatic component in the fumarolic gases at DYK was estimated to be 0.018, meanwhile it was estimated to be 0.027 for the fumarolic gases at HYK and GTP, suggesting the magma beneath DYK is depleted in volatiles relative to the magma beneath HYK and GTP. The estimated CO2/H2O ratio for the magmatic component is comparable to that of some active volcanoes in Japan, suggesting the enrichment of volatiles in the magmas beneath TVG. [Copyright &y& Elsevier]

Abstract: The chemical composition and temperature of lake water within Yugama Crater, Kusatsu-Shirane Volcano, Japan, have fluctuated markedly over the period 1966 to 2005. From 1966 to 1981, water temperature was relatively low, and Cl− and SO4 2− concentrations gradually decreased. These trends are explained by the growth of a sealing zone that formed between the region of hot rock surrounding the degassing magma and cool crust saturated with groundwater. The sealing zone acted to restrict the emission of magmatic volatiles. In 1982 and 1983, several steam-driven explosive eruptions occurred within Yugama Crater. Following the eruptions, lake temperature increased and SO4 2− and cation concentrations increased markedly, although no increase in Cl− was recorded. These changes are attributed to a breach of the sealing zone. The increased interaction of groundwater with the hot rock region surrounding the magma chamber, including the sealing zone, produced a cation- and sulfate-rich fluid that was transported to Yugama Lake. A large number of earthquakes occurred in the region of the volcano in 1990. At this time, Cl− concentrations in lake water increased rapidly, while water pH dropped. These changes are explained by the invasion of groundwater through the breached sealing zone. The invading water interacted with the inner region of hot rock close to the molten magma, and Cl stored in the hot rock was leached to the water as HCl. The HCl-enriched water was then transported to Yugama Lake, resulting in the observed increase in Cl− concentration and decrease in pH. The sequence of hot rock–water interaction followed by the extraction of HCl from hot rock recurred in 1996 to 2005, although the degree of the interaction was much smaller than the former sequence in 1982 to 1995, resulting in no occurrence of significant eruptions. [Copyright &y& Elsevier]

Abstract: Chemical and isotopic compositions were measured for volcanic gases discharged from the recently erupted Heisei-shinzan dome of Unzen volcano. The volcanic gases are largely mixed with the air, whose content ranges from 60 to 90%. Chemical and isotopic compositions of the gases are corrected for the air mixing accounting not only for the major air components but also for contribution of the atmospheric moisture and CO2. The variation of the corrected composition revealed that these gases are derived from various sources including; 1) the air circulating through the lava domes, 2) the local meteoric water at various degrees of evaporation and vapor loss, 3) the magmatic CO2 likely originated from a deep source, and 4) the gases discharged from the cooling lava dome. The gases discharged from the cooling lava dome are characterized by the oxygen and hydrogen isotopic composition typical of the subduction-type volcanoes but with high Cl content and high Cl/S and F/S ratios. In contrast, discharges of CO2 with the magmatic δ 13C values are not correlated with discharge of heat or acid gas species, suggesting the ascent of CO2-rich fluids from a deep source, possibly through the volcanic conduit. [Copyright &y& Elsevier]

Abstract: During the dome-forming eruption in 1991 to 1995 at Mt. Unzen, Japan high temperature volcanic gases were sampled from fumaroles located at the western basement of the dacitic lava dome. Comparing the composition of volcanic gas, the volatile in the pre-eruptive melt of magma and the groundmass of lava, we propose that the volatile in magma was liberated through three different gas separation steps. The first gas separation happened at depth deeper than 3.9 km. The liberated gas traveled along the conduit then discharged as the observed fumarolic gas. The second gas separation took place beneath the lava dome. The liberated gas was discharged on the top of lava dome. The third gas separation occurred near surface in a so called “open system degassing” process. The large variation in the CO2/H2O ratio of fumarolic gas could be explained by the variation of the bubble fraction in the pre-eruptive melt of magma chamber before the gas separations. The estimated bubble fraction in the melt was less than 1.7 vol.%. Such a low fraction of bubbles in the magma chamber of Mt. Unzen would be one of the reasons why the eruption was non-explosive. The fumarolic gas in the later stage of eruption was enriched in HCl and HF due to the effect of open system degassing of magma, although the gas contained CO2 and H2S with high concentrations. The CO2 and H2S would be derived from a vapor phase of hydrothermal system developed around the conduit. [Copyright &y& Elsevier]

An automatic observation buoy (AOB) was installed at Lake Nyos in March 2014. The temperature and electrical conductivity (EC) of lake water were continuously observed from March 10, 2014 to April 15, 2016. The thermocline and chemocline located deeper than −90 m subsided 15 m in the observation period due to the bottom water removal by the CO 2 degassing pipes. The velocity of subsidence was estimated quantitatively by correlating the time variation of EC obtained by AOB and the depth profile of EC. The velocity of subsidence was not constant, namely, it was fast in dry season and slow in rainy season. The time variation in the velocity of subsidence can be attributed to the seasonal variation of water flux in the degassing pipes. Considering the water balance in the deep part of lake, the flux of ground water supplied to lake was estimated to be 6.5*106 (m3/year), which is comparable to the recharge rate of ground water within the catchment area surrounding Lake Nyos. Abrupt drops in temperature and conductivity were observed at −120 m in January 2016, when the temperature at -4 m reached 21.8 °C as the lowest value. The abrupt drops are due to the sinking of surface cold water. • Lake Nyos; Limnic eruption; Automatic observation buoy; Lake water inventory; CO2 degassing pipe; Thermocline; Chemocline. [ABSTRACT FROM AUTHOR]

Definite increases in the components ratios of CO2/H2O, CO2/H2S, CO2/CH4 and He/CH4 were observed at the fumarolic gases from Owakudani geothermal area located at the center of Hakone volcanic caldera (Honshu Island, Japan), synchronized with the earthquake swarm in 2015. Such variations were due to the dominance of a magmatic component over a hydrothermal component, suggesting the earthquake swarm was produced by the injection of magmatic gases into the hydrothermal system. The CO2/H2O ratio of magmatic gas was estimated to be 0.0045 before the earthquake swarm, which increased up to 0.013 during the earthquake swarm, likely produced by the pressurization of magma as a result of magma sealing where the pressure increment in magma was estimated to be 3% to the lithostatic pressure. The H2O and CO2 concentration in magma were estimated to be 6.3 wt% and 20 wt ppm, respectively, assuming a temperature 900 °C and a rhyolitic composition. In May 2015, a few months prior to the earthquake swarm in May 2015, a sharp increase in the Ar/CO2 and N2/He ratios and a decrease in the isotopic ratio of H2O were observed at the fumarolic gas. The invasion of air into the hydrothermal system increased the Ar/CO2 and N2/He ratios. The decrease in the isotopic ratio of H2O was induced by partial condensation of H2O vapor. [ABSTRACT FROM AUTHOR]

This study reports the chemical and isotopic compositions of hot-spring waters and fumarolic gases sampled in the Jigokudani Valley of Tateyama Volcano (central Japan) in 2015 and 2016 to reveal the state of the underlying hydrothermal system. We discuss the cause of temporal variations in geochemical data in terms of temperature change in the hydrothermal system and clarify the relationship between hot-spring waters and fumarolic gases. The volcanic gas supplied from deep-seated magma was separated into liquid and vapor phases when it reached a shallow depth. Each phase formed the following three types of hot-spring water: (1) high anion concentrations and isotopic compositions similar to magmatic water, (2) lower isotopic compositions compared to type-1 waters and large variations in Cl−/SO42−, and (3) low Cl− and total anion concentrations. The formation of type-1 and type-2 hot springs was influenced by magmatic components such as HCl and SO2. We consider that type-1 hot springs are derived from the liquid phase while type-2 hot springs are derived from the vapor phase of the two-phase zone. The temporal variations in Cl−/SO42− are considered to result from temperature changes in the reservoir where liquid and vapor separated, as the HCl partitioning coefficient between the vapor and liquid phases is strongly dependent on temperature. Type-3 hot springs are derived from the vapor phase, which is depleted in HCl and SO2. We propose that the Cl− concentration of type-2 hot springs could be a measure of volcanic activity because it reflects the thermal state of the shallow two-phase zone where phreatic eruptions occur. [ABSTRACT FROM AUTHOR]

The distribution of trace metals in active stream sediments from the mineralized Lom Basin has been evaluated. Fifty-five bottom sediments were collected and the mineralogical composition of six pulverized samples determined by XRD. The fine fraction (< 150 µm) was subjected to total digestion (HClO4 + HF + HCl) and analyzed for trace metals using a combination of ICP-MS and AAS analytical methods. Results show that the mineralogy of stream sediments is dominated by quartz (39-86%), phyllosilicates (0-45%) and feldspars (0-27%). Mean concentrations of the analyzed metals are low (e.g. As = 99.40 µg/kg, Zn = 573.24 µg/kg, V = 963.14 µg/kg and Cr = 763.93 µg/kg). Iron and Mn have significant average concentrations of 28.325 and 442 mg/kg, respectively. Background and threshold values of the trace metals were computed statistically to determine geochemical anomalies of geologic or anthropogenic origin, particularly mining activity. Factor analysis, applied on normalized data, identified three associations: Ni-Cr-V-Co-As-Se-pH, Cu-Zn-Hg-Pb-Cd-Sc and Fe-Mn. The first association is controlled by source geology and the neutral pH, the second by sulphide mineralization and the last by chemical weathering of ferromagnesian minerals. Spatial analysis reveals similar distribution trends for Co-Cr-V-Ni and Cu-Zn-Pb-Sc reflecting the lithology and sulphide mineralization in the basin. Relatively high levels of As were concordant with reported gold occurrences in the area while Fe and Mn distribution are consistent with their source from the Fe-bearing metamorphic rocks. These findings provide baseline geochemical values for common and parallel geological domains in the eastern region of Cameroon. Although this study shows that the stream sediments are not polluted, the evaluation of metal composition in environmental samples from abandoned and active mine sites for comparison and environmental health risk assessment is highly recommended. [ABSTRACT FROM AUTHOR]

Magnetically guided cell delivery systems would be valuable to achieve effective macrophage-based cell therapy for colonic inflammatory diseases. In the current study, we developed a method for the efficient and simultaneous introduction of superparamagnetic iron oxide nanoparticles (SPIONs) and plasmid DNA (pDNA) into RAW264 murine macrophage-like cells using SPION-incorporated cationic liposome/pDNA complexes (magnetic lipoplexes). SPIONs and pDNA were introduced for magnetization and functionalization of the macrophages, respectively. We also evaluated the adhesive properties of magnetized RAW264 cells using magnetic lipoplexes in the murine colon under a magnetic field. Significant cellular association and gene expression without cytotoxicity were observed when magnetic cationic liposomes and pDNA were mixed at a weight ratio of 10:1, and SPION concentration and magnetic field exposure time was 0.1 mg/mL and 10 min, respectively. We also observed that cytokine production in magnetized RAW264 cells was similar to that in non-treated RAW264 cells, whereas nitric oxide production was significantly increased in magnetized RAW264 cells. Furthermore, magnetized RAW264 cells highly adhered to a Caco-2 cell monolayer and colon in mice, under a magnetic field. These results suggest that this magnetic cell delivery system can improve the colonic delivery of macrophages and its therapeutic efficacy against colonic inflammatory diseases. [ABSTRACT FROM AUTHOR]

Using a multidisciplinary approach to understand the subsurface processes behind the formation of maar‐diatreme volcanoes is of growing interest. While geophysical characterization can visualize the diatreme and the feeding dike system beneath the volcano at a reasonable scale, such data are rare and generally unavailable. Stratigraphic‐controlled sampling and geochemical analysis of pyroclasts within the ejecta ring can, however, provide substantial information on dike evolution and the influence of the magmatic plumbing system on the growth of these volcanoes. Such investigation is presented here for the Barombi Mbo Maar (BMM), a complex maar of the Cameroon Volcanic Line (CVL) composed of a pile of tephra units linked to multiple explosive phases that were grouped into three eruptive episodes. Major and trace element compositions of lavas collected from the different eruptive units indicate that the erupted magmas at BMM consist mainly of basalt, trachybasalt and basanite, with Oceanic Island Basalts (OIB) and high μ (μ = 238U/204Pb) (HIMU) signatures. Compositional modelling suggests that partial melting occurred at different degrees in the garnet‐to‐spinel transition zone from one episode to another. The repetition of eruptions with big gaps between them, the presence of another large adjacent old maar crater next to the 2.5 km crater of the BMM, and the overall similarity in geochemical compositions from one eruption to another suggest a deep high‐productive zone in the mantle beneath the BMM. The latter productive zone was capable of generating magma batches episodically to fuel several individual monogenetic eruptions at the same location. [ABSTRACT FROM AUTHOR]

Abstract A limnic eruption in 1986 at Lake Nyos in Cameroon was caused by sudden release of magmatic CO 2 dissolved in the lake water. For frequent measurements of CO 2 in the lake water, we developed a simple method of CO 2 monitoring using sound speed (SS) measurement. We measured the depth profile of sound speed at Lake Nyos in 2012, 2013, 2014, and 2015. Furthermore, in the 2014 and 2015 survey, we took movies of the underwater and the bottom of the lake using an underwater camera housed in a pressure-resistant container. The vertical change of transparency of water was checked by the visibility of reflectors set in front of the camera. A pressure sensor monitored the depth simultaneously. In both years, in addition to well-known red surface water, we discovered a cloudy layer near the upper chemocline around 100 m depth. The depth of chemocline is a good indicator of the change of total amount of CO 2 in Lake Nyos. Because the transparency can be detected by a simple optical sensor, we can now apply our low-cost monitoring tool to find the depth of chemocline for Lake Nyos. Highlights • Under-water camera system resistant to water pressure of 200 m was constructed. • Under-water movies of Lake Nyos were taken in 2014 and 2015 survey. • A script to quantify the brightness of the reflector in a movie was made and the transparency of lake water was evaluated. • We found a cloudy layer around the depth of the upper chemocline. [ABSTRACT FROM AUTHOR]

Describes the inner-salt structure of the compound, 2,2-dimorpholino-2-ethylium-1-dithioate in the crystal. Characteristics of the planes of carbenium and the thiocarboxylate moeities; Structure and reactivity of the compound; Bond lengths and angles.

We repeatedly measured isotopic compositions of noble gases and CO2 in volcanic gases sampled at six fumaroles around the Kusatsu-Shirane volcano (Japan) between 2014 and 2021 to detect variations reflecting recent volcanic activity. The synchronous increases in 3He/4He at some fumaroles suggest an increase in magmatic gas supply since 2018. The increase in magmatic gas supply is also supported by the temporal variations in 3He/CO2 ratios and carbon isotopic ratios of CO2. The 3He/40Ar* ratios (40Ar*: magmatic 40Ar) show significant increases in the period of high 3He/4He ratios. The temporal variation in 3He/40Ar* ratios may reflect changes in magma vesicularity. Therefore, the 3He/40Ar* ratio of fumarolic gases is a useful parameter to monitor the current state of degassing magma, which is essential for understanding the deep process of volcanic unrest and may contribute to identifying precursors of a future eruption. These results provide additional validation for the use of noble gas and carbon isotopic compositions of fumarolic gases for monitoring magmatic–hydrothermal systems. [ABSTRACT FROM AUTHOR]

The level of argyrophilic nucleolar organizer regions (AgNORs) and AgNOR-associated proteins (Ag-NOR proteins) varies with cell activity, including ribosomal biogenesis occurring in proliferating cells. Proteins associated with some AgNORs are detected by a specific silver staining. To investigate a possible relationship between apoptosis and the AgNORs or Ag-NOR proteins, we examined the changes of AgNORs and Ag-NOR proteins during apoptosis in a human salivary gland cell line, HSG cells, and a human oral squamous carcinoma cell line, SCC-25 cells. Apoptosis was induced by treatment of HSG and SCC-25 cells with okadaic acid. Proteins prepared from HSG and SCC-25 cells treated with varying concentrations of okadaic acid (OA) were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by transferring to transfer membranes and staining for Ag-NOR proteins by modified Western blot analysis. Four major bands (110 kDa, 43 kDa, 39kDa, and 37 kDa) were detected in the proteins obtained from the control cells. The level of the 110-kDa protein decreased in the proteins prepared from OA-induced apoptotic cells; however, the reaction intensity of the other three bands was changed in apoptotic cells. An additional band of an 80-kDa Ag-NOR protein appeared and increased in the apoptotic cells. Cellular fractionation of HSG cells and SCC-25 cells was done with or without apoptotic induction. An 80-kDa Ag-NOR protein was detected in the nuclear fraction prepared from the apoptotic cells, while the 110-kDa protein decreased in the nuclear fraction of these cells. The 110-kDa Ag-NOR protein may be nucleolin (C23) as deduced from its AgNOR staining features, including molecular weight. The 80-kDa protein may be the cleavage product of the 110-kDa protein. In the cell-free apoptotic system, in which intact nuclei of HSG cells were incubated with the cytosol fraction of apoptotic HSG and SCC-25 cells, the 80-kDa Ag-NOR protein was detected in nuclei incubated with the cytosol fraction of apoptotic cells, while the level of the 110-kDa protein decreased. The changes of Ag-NOR proteins in nuclei prepared from SCC-25 cells incubated with cytosol fractions prepared from HSG and SCC-25 cells were identical to those of the HSG cells. The alternation of AgNORs in apoptosis-induced HSG cells was also examined using double staining with Hoechst 33342 and silver nitrate. Hoechst staining revealed typical apoptotic nuclei, which exhibited highly fluorescent condensed chromatin in OA-treated HSG cells. Silver grains representing AgNORs were not detected in the cells undergoing apoptosis. The dual-imposition view confirmed that AgNORs, which are visible as dots in nucleoli in the control cells, disappeared from the apoptotic nuclei of HSG cells. Our results indicate that the 110-kDa nucleolar Ag-NOR protein is associated with apoptosis and is cleaved during apoptosis. [ABSTRACT FROM AUTHOR]

• Magnetic liposomes enable the efficient magnetization of mesenchymal stem cells. • Magnetized MSCs were much retained in mouse skeletal muscle under a magnetic field. • Magnetized MSCs showed high immunomodulatory effects on inflamed skeletal muscle. Sarcopenia, an age-related reduction in skeletal muscle mass and strength, is mainly caused by chronic inflammation. Because mesenchymal stem cells (MSCs) have the capacity to both promote myogenic cell differentiation and suppress inflammation, they are a promising candidate for sarcopenia treatment. In this study, to achieve the long-term retention of MSCs in skeletal muscle, we prepared magnetized MSCs using magnetic anionic liposome/atelocollagen complexes that we had previously developed, and evaluated their retention efficiency and immunomodulatory effects in mouse inflamed skeletal muscle. Mouse MSCs were efficiently magnetized by incubation with magnetic anionic liposome/atelocollagen complexes for 30 min under a magnetic field. The magnetized MSCs differentiated normally into osteoblasts and adipocytes. Additionally, non-magnetized MSCs and magnetized MSCs increased IL-6 and inducible nitric oxide synthase mRNA expression and decreased TNF-α and IL-1β mRNA expression in C2C12 mouse skeletal muscle myotubes through paracrine effects. Moreover, magnetized MSCs were significantly retained in cell culture plates and mouse skeletal muscle after their local injection in the presence of a magnetic field. Furthermore, magnetized MSCs significantly increased IL-6 and IL-10 mRNA expression and decreased TNF-α and IL-1β mRNA expression in inflamed skeletal muscle. These results suggest that magnetized MSCs may be useful for effective sarcopenia treatment. [ABSTRACT FROM AUTHOR]

Even though ca 1746 people and over 3000 cattle were killed in 1986 by sudden release of about 800 million m3 of CO 2 from Lake Nyos volcano in northwest Cameroon, the lake's formation history is not known. Here we report results of a lithostratigraphic and petrogenetic study of Nyos volcano that allows us to confirm its phreatomagmatic (maar) origin. Eruptive products are divided into 2 units, the phases of each of which are closely related in time. Unit A comprises 4 phases, the last (A-4) represents the cataclysmic phreatomagmatic formation of Nyos maar and may have been triggered by collapse of the vent system of the previous (A-1 to A-3) phases, and/or reactivation of basement faults. After a repose period, activity shifted NE of the maar to form Unit B products. The B-1 phase of this unit deposited the scoria now covering most of the Lake Nyos area. Unit B-2 constructed the Fon's cone. A small lava flow (Unit B-3) represents the latest phase of volcanic activity of Nyos volcano. Based on area-thickness estimation methods, a total of ca 0.8 km3 of eruptive material was produced from the volcano. Geochemical data suggest that magma of the 2 units probably formed by melting of the same garnet-bearing OIB-like asthenospheric mantle source, and evolved mainly by crustal contamination and fractional crystallization in independent magma batches that erupted without mixing. Our results provide a basis for advice on general hazard mitigation in the Lake Nyos area. • Eruptive products from Nyos (0.8 km3) are divided into 2 units, each of which are from different monogenetic volcanoes. • Magma of 2 units generated by melting of same garnet-bearing OIB-like mantle source and evolved independently without mixing. • The results including lithostratigraphy, geologic map, magma genesis of Nyos provide an important basis for risk management. [ABSTRACT FROM AUTHOR]

Abstract The most important part of geochemical studies of lavas along the Cameroon Volcanic Line (CVL) has so far focused on the southern and central segments of the line leaving behind the northern-most part of the CVL with few and incomplete data. This study presents the case of the Gawar, Zamay and Minawao volcanoes, for which, for the first time, petrological and geochemical data comprising major and trace elements, and Strontium-Neodymium-Lead isotopes have been used to investigate the mantle source and the genetic relation between the felsic and mafic lavas in these areas. Volcanics in the Gawar are mainly basanites while those from Minawao and Zamay are essentially trachytes. The Nb/Ta and Zr/Hf ratios are similar for both the mafic and felsic rocks suggesting a dominant evolution of the magma by fractional crystallization. Primitive-mantle normalized multi-element diagrams of the mafic lavas are comparable to those reported in other volcanoes along the CVL; characterized by the depletion of Heavy Rare Earth Elements (HREE) and enrichment of Light Rare Elements (LREE), indicative of an enrichment and the presence of garnet in the source. Modeled results for melting using primitive mantle normalized values of Sm/Yb vs La/Sm indicate a low degree (<2%) of partial melting of a source with less than 4% garnet. This is consistent with chondrite normalized REE patterns characterized by the fractionation of HREE relative LREE. Trace elements composition and isotope data preclude the significant role of the continental crust in the magmatism of the mafic rocks. However, during evolution to the felsic lavas, the role of the crust became more important. The ranges for 87Sr/86Sr (0.70356–0.70362), 143Nd/144Nd (0.512928–0.512931), 206Pb/204Pb (19.62–19.72), 207Pb/204Pb (15.65–15.68) and 208Pb/204Pb (39.31–39.45) isotopic composition for mafic samples (Gawar) are limited and fall within the range of mafic lavas studied along the CVL. The isotopic signatures and trace element characteristics are consistent with an asthenospheric origin, however with contribution from the sub-continental lithospheric Mantle (SCLM). The two sources have imparted characteristics of more than two mantle components involving the Depleted MORB-like mantle, HIMU and Enriched mantle (EM1). Highlights • Geochemical data and Sr-Nd-Pb isotopes have been used to explore the mantle source. • Similar Nb/Ta and Zr/Hf ratios suggest magma evolution by fractional crystallization. • Sm/Yb vs La/Sm graph show <2% partial melting of a source with ≈4% garnet. • The ranges for isotopic data of mafic samples are within the range of CVL lavas. • Isotopic and trace element data are consistent with an asthenospheric origin. [ABSTRACT FROM AUTHOR]

Abstract After the catastrophic release of CO 2 gas from Lake Nyos in 1986, much emphasis has been put on the urgency of adopting an efficient strategy for reducing CO 2 accumulation at depth, but the environmental impacts of the degassing activity have been mostly neglected. The degassing pipes are continuously releasing highly concentrated ferrous iron water to the surface of the lake. The lake surface, which once used to be a deep blue, has now changed into reddish brown, due to the formation of colloidal ferric iron. From December 2001 to January 2011, one degassing pipe transported 560 tons of iron as colloidal ferric iron per year, and after late 2011, three pipes have been transporting about 1100 tons per year. The degassing fountain contains highly concentrated calcium and magnesium other than iron resulting in enrichment of those substances. Although the colloidal ferric iron might have adverse effect on fish and/or other aqueous biota, the lake water remained safe for domestic water use. Highlights • Surface color of Lake Nyos changed into reddish brown by colloidal ferric iron uplifted through CO 2 degassing pipes. • 560 ton/year of ferric iron was scattered through one pipe during 2001 to 2011. • 1,100 ton/year of ferric iron was scattered over after the installation of three pipes in late 2011. • Highly concentrated colloidal ferric iron might have adverse effects on fish or other aqueous biota. • Environmental impact of the degassing process was not significant to affect human health for domestic water use. [ABSTRACT FROM AUTHOR]

Abstract Lake Nyos is a meromictic lake with strong stratification separated into 4 distinct layers; shallow, intermediate, transitional, and bottom layers. This article discusses enrichment of Fe2+ in the bottom water in January 2003 when the effect of artificial degassing that started in January 2001 on the chemical structure of the lake was still minimal. In the bottom layer (205.5–209.5 m), Fe2+ and HCO 3 − are the major dissolved species and their concentrations increase sharply toward the bottom. Enrichment of Fe2+ and HCO 3 − is most likely caused by anaerobic microbial reduction of Fe(OH) 3 precipitates at the water-sediment interface. The Fe(OH) 3 precipitates sank to the bottom after atmospheric oxidation of Fe2+ dispersed by the degassing pipe. Lateritic hematite may also participate in the reduction reaction. Production of Fe2+ and HCO 3 − significantly increases the alkalinity and electric conductivity of the bottom-most water and is responsible for a small rise of pH between 205 m and 209.5 m, the bottom. The other dissolved species, e.g., Na+, K+, Ca2+, Mg2+, SiO 2(aq) etc., result from the CO 2 -water-basalt interaction at low temperatures (25°∼30 °C) in the sub-lacustrine fluid reservoir that is believed to exist in the diatreme beneath the lake bottom, and they seep into the bottom layer. Highlights • High enrichment of Fe2+ and HCO3− in Lake Nyos bottom water. • This enrichment was caused by anaerobic microbial reduction of Fe(OH)3 at the water-sediment interface. [ABSTRACT FROM AUTHOR]

Abstract A combined study of major ions, δ18O, δD, 13C, 87Sr/86Sr isotopes, X-ray diffraction, scanning electron microscopy, and electron probe microanalyses on springs and spring mineral precipitates along the Cameroon Volcanic Line (CVL) was undertaken to understand water chemistry, and infer the type and origin of the precipitates. The waters are of evaporated Na + K Cl and non-evaporated Ca + Mg HCO 3 types, with the more mineralized (electrical conductivity-EC of 13130 μS/cm) Lobe spring inferred to result from interaction of circulating 49 °C waters with magmatic volatiles of the active Mt. Cameroon. Water mineralization in the other springs follows the order: Sabga A > Sabga B > Bambui B > Bambui A > Nyos Cave. But for the Nyos Cave spring, all other springs contain fluoride (up to 0.5–35.6 mg/l above WHO potable water upper limit). The Sabga spring contains arsenic (up to 1.3 mg/l above the WHO limits). The springs show low fractionation temperatures in the range of 19–43 ᵒC. The Lobe and Sabga A springs are precipitating dolomite (CaMg(CO 3) 2), while the Nyos Cave, Bambui A, Bambui B and Sabga B springs precipitate trona ((Na 3 H(CO 3) 2.H 2 O). Our data suggest a marine provenance for the carbonates, and point to a volcanic input for the Lobe, Nyos, Sabga A, and Bambui A springs. The latter springs are therefore proposed as proxies for monitoring volcanic activity for hazard mitigation along the CVL. [ABSTRACT FROM AUTHOR]

The hydrodynamic fragmentation that formed Lake Nyos in northwest Cameroon did not only make it the most unpopular lake in the world from a gas disaster perspective, it also opened a rare and formidable window through which much of the geology of Cameroon can be studied in a single locality. The Cambrian quartz monzonite cliff excavated by the maar-forming explosion and exposed in its northeastern shore is intruded by mafic dykes, two of which we dated. Even though close to one another, the dykes are different in composition. The alkaline dyke yields a slightly older (Carnian) K-Ar fedspar age of 231.1 ± 4.8 Ma, while the sub alkaline dyke yields an age of 224.8 ± 4.7 Ma (Norian). Based on radioisotopic age data available over the last 48 years (347 data) for the Cameroon Line magmatism comprising eruptives and volcano-plutonic complexes, the Nyos dykes are way older than the Cameroon Line, and even pre-date the Lower Cretaceous initiation of west Gondwana fragmentation in Equatorial Atlantic domain. They would therefore not have been directly linked to the formation of the Cameroon Line. Alternatively, they might be associated with the development of intra-continental rift systems in West Central Africa that pre-dated west Gondwana breakup to form the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Groundwater is used by 3 million inhabitants in the coastal urban city of Douala, Cameroon, but comprehensive data are too sparse for it to be managed in a sustainable manner. Hence this study aimed to (1) assess the potability of the groundwater; (2) evaluate the spatial variation of groundwater composition; and (3) assess the interaction and recharge mechanisms of different water bodies. Hydrogeochemical tools and methods revealed the following results in the Wouri and Nkappa formations of the Douala basin, which is beneath Douala city: 30% of water samples from hand-dug wells in the shallow Pleistocene alluvium aquifer were saline and highly mineralized. However, water from boreholes in the deeper (49–92 m depth) Palaeocene aquifer was saline-free, less mineralized and potable. Water in the shallow aquifer (0.5–22 m depth) was of Na+-K+-Cl−-NO3−type and not potable due to point source pollution, whereas Ca+-HCO3−unpolluted water dominates in the deeper aquifer. Water in the deep and shallow aquifers indicates the results of preferential flow pass and evaporative recharge, respectively. Possible hydrogeochemical processes include point source pollution, reverse ion exchange, remote recharge areas and mixing of waters with different chemical signatures.EDITOR D. Koutsoyiannis ASSOCIATE EDITOR M.D. Fidelibus [ABSTRACT FROM PUBLISHER]

This study clarifies the hydrothermal system of Jigokudani Valley near Mt. Tateyama volcano in Japan by using a combination of audio-frequency magnetotelluric (AMT) survey and hot-spring water analysis in order to assess the potential of future phreatic eruptions in the area. Repeated phreatic eruptions in the area about 40,000 years ago produced the current valley morphology, which is now an active solfatara field dotted with hot springs and fumaroles indicative of a well-developed hydrothermal system. The three-dimensional (3D) resistivity structure of the hydrothermal system was modeled by using the results of an AMT survey conducted at 25 locations across the valley in 2013–2014. The model suggests the presence of a near-surface highly conductive layer of < 50 m in thickness across the entire valley, which is interpreted as a cap rock layer. Immediately below the cap rock is a relatively resistive body interpreted as a gas reservoir. Field measurements of temperature, pH, and electrical conductivity (EC) were taken at various hot springs across the valley, and 12 samples of hot-spring waters were analyzed for major ion chemistry and H 2 O isotopic ratios. All hot-spring waters had low pH and could be categorized into three types on the basis of the Cl − /SO 4 2 − concentration ratio, with all falling largely on a mixing line between magmatic fluids and local meteoric water (LMW). The geochemical analysis suggests that the hydrothermal system includes a two-phase zone of vapor–liquid. A comparison of the resistivity structure and the geochemically inferred structure suggests that a hydrothermal reservoir is present at a depth of approximately 500 m, from which hot-spring water differentiates into the three observed types. The two-phase zone appears to be located immediately beneath the cap rock structure. These findings suggest that the hydrothermal system of Jigokudani Valley exhibits a number of factors that could trigger a future phreatic eruption. [ABSTRACT FROM AUTHOR]

Lake Nyos is located at the summit of a stratovolcano in the Oku Volcanic Group (OVG) along the Cameroon Volcanic Line. The sudden release of magmatic CO 2 trapped at the bottom of Lake Nyos in August 1986 caused historical casualties of 1750 people and over 3000 cattle. New geochemical data of volcanic rocks from the Nyos volcano and the first available data for volcanic rocks from other maar-bearing volcanoes (Lakes Elum, Wum and Oku) in the OVG are presented and compared. Lavas from the Nyos, Elum and Wum volcanoes show similarities in major and trace elements and Sr–Nd–Pb isotopes, suggestive of a similar mantle source. However, this source is slightly different from that of the Oku volcano. The samples from Lake Oku have lower alkali, higher TiO 2 and more depletion and enrichment in most incompatible trace elements than those from the Nyos, Elum and Wum volcanoes. These differences and those observed in the Sr–Nd–Pb results are consistent with a heterogeneous source for lavas in the OVG. Trace element compositions suggested the presence of garnet in the source (< 6% garnet) and modelled melting results indicate < 2% partial melting of the source material. Isotope data plot within the focal zone, extending towards enriched mantle 1 (EM1; e.g. Lakes Oku and Nyos samples). This indicates the involvement of at least three mantle components: depleted mid-ocean ridge basalt mantle, high-μ and EM1 components in the magmatism of the lavas studied. The contributions of these components in different proportions, originating from asthenospheric and subcontinental lithospheric mantle sources, can account for the observed variations in geochemical characteristics. The geochemical characteristics of the studied lavas indicate that the magma source need not necessarily have an abnormal CO 2 concentration to pose a potential threat. Degassing of an ordinary magma chamber and the migration of gas to the bottom of the lakes through cracks and faults can lead to the accumulation of CO 2 in lake bottoms. This is controlled by tectonic parameters (fractures and faults) that enhance degassing from the magma chamber to the lake bottom and physical parameters of the lake (e.g. size, depth, temperature and solubility) that control CO 2 stability. [ABSTRACT FROM AUTHOR]

Summary The shallow aquifer in the vicinity of Lake Nyos (Northwest, Cameroon) is one of the main water supply sources to meet the water needs of the inhabitants to be resettled after 1986s tragedy. Unfortunately, there is a lack of knowledge on the groundwater recharge and flow systems in the area. Multiple environmental tracers (δ 18 O, δD, Cl − , CFCs and SF 6 ) and a yearly record of rainfall, surface waters and groundwater were employed to characterize the recharge mechanism of the shallow groundwater seeping in the fractured rock of the Lake Nyos catchment (LNC). The δ 18 O–δD relationship of the rainfall events gave the Nyos Meteoric Water Line: δD = 8.28 δ 18 O + 11.87. Inland moisture vapor may have impacted the isotopic composition of original vapor masses from Gulf of Guinea prior to precipitation. Shallow groundwater in the LNC shows a similar trend of enrichment in 18 O and D as surface waters indicating a well-mixed aquifer. The proportions of surface waters and rainfall in the groundwater reservoir were 87% and 13%, respectively. The high annual recharge rate (941 mm/yr) and the seasonal variability in the isotopic signatures of groundwater indicate a renewable aquifer system. CFCs apparent ages-based piston flow model revealed a young age (average of 24 a.) of the groundwater in the LNC. SF 6 -based ages were biased young as compared to relatively younger than CFCs-based ages, implying an additional terrigenic production of SF 6 . The conceptual model for groundwater flow suggests that three main flow regimes, mainly controlled by the physical properties of the rock heterogeneities govern the movement of water in the aquifer. The piston flow model appears, however, to be the better model to explain the flow regime in the highly faulted and fissured area where recharge occurs (∼1200–1600 masl). The rapid circulation and the low solubility lead to low mineralization. In the middle-lower area where waters circulate more in the weathered layer, exponential mixing model dominates, yielding more mineralized water. Downward to the valley, with prevailing gentle slope, interaction between surface and recently infiltrated groundwater better explain the observed similarity in the isotopic compositions and the mineralization of water. [ABSTRACT FROM AUTHOR]

Since the catastrophic releases of CO2 in the 1980s, Lakes Nyos and Monoun in Cameroon experienced CO2 recharge at alarming rates of up to 80 mol/m² per yr. Total gas pressures reached 8.3 and 15.6 bar in Monoun (2003) and Nyos (2001), respectively, resulting in gas saturation levels up to 97%. These natural hazards are distinguished by the potential for mitigation to prevent future disasters. Controlled degassing was initiated at Nyos (2001) and Monoun (2003) amid speculation it could inadvertently destabilize the lakes and trigger another gas burst. Our measurements indicate that water column structure has not been compromised by the degassing and local stability is increasing in the zones of degassing. Furthermore, gas content has been reduced in the lakes ≈12-14%. However, as gas is removed, the pressure at pipe inlets is reduced, and the removal rate will decrease overtime. Based on 12 years of limnological measurements we developed a model of future removal rates and gas inventory, which predicts that in Monoun the current pipe will remove ≈30% of the gas remaining before the natural gas recharge balances the removal rate. In Nyos the single pipe will remove ≈25% of the gas remaining by 2015; this slow removal extends the present risk to local populations. More pipes and continued vigilance are required to reduce the risk of repeat disasters. Our model indicates that 75-99% of the gas remaining would be removed by 2010 with two pipes in Monoun and five pipes in Nyos, substantially reducing the risks. [ABSTRACT FROM AUTHOR]

To investigate the behavior of nuclear proteins in apoptotic cells, we examined the changes in nucleolin and proteins of the nucleolar organizing region during apoptosis in human osteoblastic cell lines, Saos-2 and MG63. Apoptosis was induced by treatment of these cells with okadaic acid. Proteins prepared from apoptotic cells were subjected to Western blot analysis and a modified Western blot method using silver nitrate. The anti-nucleolin antibody recognized the 110-kDa band and the staining intensity of this band decreased in the proteins prepared from the okadaic acid-treated apoptotic cells. The additional band of an 80-kDa was also detected in the proteins prepared from the apoptotic cells. Two major silver nitrate-stained bands, 110-kDa and 37-kDa, were detected among the proteins obtained from control cells. Like the Western blot analysis, the intensity of the 110-kDa silver nitrate-staining band decreased; an 80-kDa band appeared and its staining intensity increased in the lysate from the okadaic acid-treated cells. The signal intensity of the 37-kDa protein did not change in the sample from the apoptotic cells. In a cell-free apoptotic system, the 80-kDa protein was also detected and the amount of the 110-kDa protein decreased in the extract of Saos-2 cell nuclei incubated with apoptotic cytosol. The change in nucleolin in Saos-2 cells induced to undergo apoptosis was examined by an immunocytochemical procedure using the anti-nucleolin antibody and Hoechst 33342. Nucleolin was visible as dots in nucleoli in the control cells; however, it was not detected in the cells undergoing apoptosis. The dual-exposure view of Hoechst 33342 and anti-nucleolin staining cells confirmed that nucleolin had disappeared from the apoptotic nuclei of Saos-2. [Copyright &y& Elsevier]

Remote sampling of water from Yugama crater lake at Kusatsu-Shirane volcano, Japan, was performed using a drone. Despite the high altitude of over 2000 m above sea level, our simple method was successful in retrieving a 250 mL sample of lake water. The procedure presented here is easy for any researcher to follow who operates a drone without additional special apparatus. We compare the lake water sampled by drone with that sampled by hand at a site where regular samplings have previously been carried out. Chemical concentrations and stable isotope ratios are largely consistent between the two techniques. As the drone can fly automatically with the aid of navigation by Global Navigation Satellite System (GNSS), it is possible to repeatedly sample lake water from the same location, even when entry to Yugama crater lake is restricted due to the risk of eruption. [ABSTRACT FROM AUTHOR]