Measurement of exchangeable cations in saline soils

The measurement of exchangeable cations in saline soils is limited by the difficulty in accurately separating soluble cations from exchangeable cations. A method is examined for saline soils in which exchangeable cations are calculated as the total extractable cations minus the concentration of soil solution (soluble) cations. In addition, a further two standard methods were investigated, one which assumes the total soil extractable cations are exchangeable, the other utilises a pretreatment to remove soluble salts prior to measurement of the remaining (exchangeable) cations. After equilibration with a range of sodium adsorption ratio (SAR) solutions at various ionic strengths, the exchangeable cation concentrations of two soils (Dermosol and Vertosol) were determined by these methods and compared to known values. The assumption that exchangeable cations can be estimated as the total soil extractable cations, although valid at low ionic strength, resulted in an overestimation of exchangeable Na and Ca concentrations at higher ionic strengths due to the presence of soluble salts. Pretreatment with ethanol and glycerol was found to effectively remove soluble salts thus allowing the accurate measurement of the effective cation exchange capacity (ECEC), however, dilution associated with the pretreatment process decreased concentrations of exchangeable Ca while simultaneously increasing exchangeable Na. Using the proposed method, good correlations were found between known and measured concentrations of exchangeable Na (Dermosol: y=0.873x and Vertosol: y=0.960x) and Ca (Dermosol: y=0.906x, and Vertosol: y=1.05x). Therefore, for soils with an ionic strength of approximately 50 mM (ECse 4 dS m-1) or greater (in which exchangeable cation concentrations are overestimated by assuming the total soil cations are exchangeable), concentrations can be calculated as difference between total extractable cations and soluble cations.

Measurement and modelling of controlled beach groundwater levels under wave action

New laboratory scale experimental data are presented on the forcing of beach groundwater levels by wave run-up. The experimental setup simulates a coastal barrier dividing the ocean from a relatively constant back beach water level, conditions approximating a closed off lagoon system or beach aquifer. The data are critically compared to an advanced numerical model for simulating wave and beach groundwater interaction in the coastal zone, and provide the first experimental verification of such a model. Overall model-data comparisons are good, but some systematic discrepancies are apparent, and reasons for these are discussed.

The effects of substrate water availability on the isolation and growth of fungi

The work reported in this thesis was carried out to contribute to the knowledge of the effects of substrate water availability or water activity (a ) on fungal growth parameters and its implications in the preparationw of materials susceptible to biodeterioration. Fungi were isolated from soils of different ecological sites at a range of substrate aw levels controlled by sodium chloride (NaCl). Three groups of fungi were isolated : firstly, those isolated only at high a (aw about 0.997).secondly, those isolated at high and decreasing aw (aw 0.997 to 0.85) and finally, those isolated at only decreased aw (aw O.95 to 0.80). From these isolations, test fungi were selected to study the effects of pH, temperature, exo-enzyme production and biocide efficacy at decreased aw levels, with glycerol and NaCl as a controlling solutes. The linear extension rates of the fungi increased at all test pH values near optimum a of growth. Test fungi of the Aspergillus glaucus group were found to be most resistant to low aw. Growth and survival of vegetative and fruiting bodies at elevated temperatures were enhanced with the addition of a controlling solutes. A. flavus, A. fumigatus displayed high heat resistance and A. amstelodami, A. versicolor and Penicillium citrinum displayed low heat resistance at high aw levels and vice versa at low aw levels. Amylase, lipase and protease activities were studied at lowered aw , using modifications of the test tube method of Raute11a and Cowling. Amylase and protease production in most xerophilic fungi ceased around 0.80 aw , but lipase production in some xerophilic fungi, including A. glatlcus fungi, was up to and including 0.70 aw with g1ycero1.

Gas hydrate investigation at the Amsterdam mud volcano

We investigated gas hydrate in situ inventories as well as the composition and principal transport mechanisms of fluids expelled at the Amsterdam mud volcano (AMV; 2,025 m water depth) in the Eastern Mediterranean Sea. Pressure coring (the only technique preventing hydrates from decomposition during recovery) was used for the quantification of light hydrocarbons in near-surface deposits. The cores (up to 2.5 m in length) were retrieved with an autoclave piston corer, and served for analyses of gas quantities and compositions, and pore-water chemistry. For comparison, gravity cores from sites at the summit and beyond the AMV were analyzed. A prevalence of thermogenic light hydrocarbons was inferred from average C1/C2+ ratios <35 and d13C-CH4 values of -50.6 per mil. Gas venting from the seafloor indicated methane oversaturation, and volumetric gas-sediment ratios of up to 17.0 in pressure cores taken from the center demonstrated hydrate presence at the time of sampling. Relative enrichments in ethane, propane, and iso-butane in gas released from pressure cores, and from an intact hydrate piece compared to venting gas suggest incipient crystallization of hydrate structure II (sII). Nonetheless, the co-existence of sI hydrate can not be excluded from our dataset. Hydrates fill up to 16.7% of pore volume within the sediment interval between the base of the sulfate zone and the maximum sampling depth at the summit. The concave-down shapes of pore-water concentration profiles recorded in the center indicate the influence of upward-directed advection of low-salinity fluids/fluidized mud. Furthermore, the SO42- and Ba2+ pore-water profiles in the central part of the AMV demonstrate that sulfate reduction driven by the anaerobic oxidation of methane is complete at depths between 30 cm and 70 cm below seafloor. Our results indicate that methane oversaturation, high hydrostatic pressure, and elevated pore-water activity caused by low salinity promote fixing of considerable proportions of light hydrocarbons in shallow hydrates even at the summit of the AMV, and possibly also of other MVs in the region. Depending on their crystallographic structure, however, hydrates will already decompose and release hydrocarbon masses if sediment temperatures exceed ca. 19.3°C and 21.0°C, respectively. Based on observations from other mud volcanoes, the common occurrence of such temperatures induced by heat flux from below into the immediate subsurface appears likely for the AMV.

Water-, pH- and temperature relations of germination for the extreme xerophiles Xeromyces bisporus (FRR 0025), Aspergillus penicillioides (JH06THJ), and Eurtotium halophilicum (FRR 2471)

Water activity, temperature and pH are determinants for biotic activity of cellular systems, biosphere function and, indeed, for all life processes. This study was carried out at high concentrations of glycerol, which concurrently reduces water activity and acts as a stress protectant, to characterize the biophysical capabilities of the most extremely xerophilic organisms known. These were the fungal xerophiles: Xeromyces bisporus (FRR 0025), Aspergillus penicillioides (JH06THJ) and Eurotium halophilicum (FRR 2471). High-glycerol spores were produced and germination was determined using 38 media in the 0.995–0.637 water activity range, 33 media in the 2.80–9.80 pH range and 10 incubation temperatures, from 2 to 50°C. Water activity was modified by supplementing media with glycerol+sucrose, glycerol+NaCl and glycerol+NaCl+sucrose which are known to be biologically permissive for X. bisporus, A. penicillioides and E. halophilicum respectively. The windows and rates for spore germination were quantified for water activity, pH and temperature; symmetry/asymmetry of the germination profiles were then determined in relation to supra- and sub-optimal conditions; and pH- and temperature optima for extreme xerophilicity were quantified. The windows for spore germination were ~1 to 0.637 water activity, pH 2.80–9.80 and > 10 and < 44°C, depending on strain. Germination profiles in relation to water activity and temperature were asymmetrical because conditions known to entropically disorder cellular macromolecules, i.e. supra-optimal water activity and high temperatures, were severely inhibitory. Implications of these processes were considered in relation to the in-situ ecology of extreme conditions and environments; the study also raises a number of unanswered questions which suggest the need for new lines of experimentation.

Understanding and validating accelerometry as a measure of physical activity in children with intellectual disabilities

Background Physical activity in children with intellectual disabilities is a neglected area of study, which is most apparent in relation to physical activity measurement research. Although objective measures, specifically accelerometers, are widely used in research involving children with intellectual disabilities, existing research is based on measurement methods and data interpretation techniques generalised from typically developing children. However, due to physiological and biomechanical differences between these populations, questions have been raised in the existing literature on the validity of generalising data interpretation techniques from typically developing children to children with intellectual disabilities. Therefore, there is a need to conduct population-specific measurement research for children with intellectual disabilities and develop valid methods to interpret accelerometer data, which will increase our understanding of physical activity in this population. Methods Study 1: A systematic review was initially conducted to increase the knowledge base on how accelerometers were used within existing physical activity research involving children with intellectual disabilities and to identify important areas for future research. A systematic search strategy was used to identify relevant articles which used accelerometry-based monitors to quantify activity levels in ambulatory children with intellectual disabilities. Based on best practice guidelines, a novel form was developed to extract data based on 17 research components of accelerometer use. Accelerometer use in relation to best practice guidelines was calculated using percentage scores on a study-by-study and component-by-component basis. Study 2: To investigate the effect of data interpretation methods on the estimation of physical activity intensity in children with intellectual disabilities, a secondary data analysis was conducted. Nine existing sets of child-specific ActiGraph intensity cut points were applied to accelerometer data collected from 10 children with intellectual disabilities during an activity session. Four one-way repeated measures ANOVAs were used to examine differences in estimated time spent in sedentary, moderate, vigorous, and moderate to vigorous intensity activity. Post-hoc pairwise comparisons with Bonferroni adjustments were additionally used to identify where significant differences occurred. Study 3: The feasibility on a laboratory-based calibration protocol developed for typically developing children was investigated in children with intellectual disabilities. Specifically, the feasibility of activities, measurements, and recruitment was investigated. Five children with intellectual disabilities and five typically developing children participated in 14 treadmill-based and free-living activities. In addition, resting energy expenditure was measured and a treadmill-based graded exercise test was used to assess cardiorespiratory fitness. Breath-by-breath respiratory gas exchange and accelerometry were continually measured during all activities. Feasibility was assessed using observations, activity completion rates, and respiratory data. Study 4: Thirty-six children with intellectual disabilities participated in a semi-structured school-based physical activity session to calibrate accelerometry for the estimation of physical activity intensity. Participants wore a hip-mounted ActiGraph wGT3X+ accelerometer, with direct observation (SOFIT) used as the criterion measure. Receiver operating characteristic curve analyses were conducted to determine the optimal accelerometer cut points for sedentary, moderate, and vigorous intensity physical activity. Study 5: To cross-validate the calibrated cut points and compare classification accuracy with existing cut points developed in typically developing children, a sub-sample of 14 children with intellectual disabilities who participated in the school-based sessions, as described in Study 4, were included in this study. To examine the validity, classification agreement was investigated between the criterion measure of SOFIT and each set of cut points using sensitivity, specificity, total agreement, and Cohen’s kappa scores. Results Study 1: Ten full text articles were included in this review. The percentage of review criteria met ranged from 12%−47%. Various methods of accelerometer use were reported, with most use decisions not based on population-specific research. A lack of measurement research, specifically the calibration/validation of accelerometers for children with intellectual disabilities, is limiting the ability of researchers to make appropriate and valid accelerometer use decisions. Study 2: The choice of cut points had significant and clinically meaningful effects on the estimation of physical activity intensity and sedentary behaviour. For the 71-minute session, estimations for time spent in each intensity between cut points ranged from: sedentary = 9.50 (± 4.97) to 31.90 (± 6.77) minutes; moderate = 8.10 (± 4.07) to 40.40 (± 5.74) minutes; vigorous = 0.00 (± .00) to 17.40 (± 6.54) minutes; and moderate to vigorous = 8.80 (± 4.64) to 46.50 (± 6.02) minutes. Study 3: All typically developing participants and one participant with intellectual disabilities completed the protocol. No participant met the maximal criteria for the graded exercise test or attained a steady state during the resting measurements. Limitations were identified with the usability of respiratory gas exchange equipment and the validity of measurements. The school-based recruitment strategy was not effective, with a participation rate of 6%. Therefore, a laboratory-based calibration protocol was not feasible for children with intellectual disabilities. Study 4: The optimal vertical axis cut points (cpm) were ≤ 507 (sedentary), 1008−2300 (moderate), and ≥ 2301 (vigorous). Sensitivity scores ranged from 81−88%, specificity 81−85%, and AUC .87−.94. The optimal vector magnitude cut points (cpm) were ≤ 1863 (sedentary), ≥ 2610 (moderate) and ≥ 4215 (vigorous). Sensitivity scores ranged from 80−86%, specificity 77−82%, and AUC .86−.92. Therefore, the vertical axis cut points provide a higher level of accuracy in comparison to the vector magnitude cut points. Study 5: Substantial to excellent classification agreement was found for the calibrated cut points. The calibrated sedentary cut point (ĸ =.66) provided comparable classification agreement with existing cut points (ĸ =.55−.67). However, the existing moderate and vigorous cut points demonstrated low sensitivity (0.33−33.33% and 1.33−53.00%, respectively) and disproportionately high specificity (75.44−.98.12% and 94.61−100.00%, respectively), indicating that cut points developed in typically developing children are too high to accurately classify physical activity intensity in children with intellectual disabilities. Conclusions The studies reported in this thesis are the first to calibrate and validate accelerometry for the estimation of physical activity intensity in children with intellectual disabilities. In comparison with typically developing children, children with intellectual disabilities require lower cut points for the classification of moderate and vigorous intensity activity. Therefore, generalising existing cut points to children with intellectual disabilities will underestimate physical activity and introduce systematic measurement error, which could be a contributing factor to the low levels of physical activity reported for children with intellectual disabilities in previous research.

The study of correlation between sea surface temperature (SST) by using the NOAA-AVHRR data and compare this data with temperature measurement in the Caspian Sea

The changes in time and location of surface temperature from a water body has an important effect on climate activities, marine biology, sea currents, salinity and other characteristics of the seas and lakes water. Traditional measurement of temperature is costly and time consumer due to its dispersion and instability. In recent years the use of satellite technology and remote sensing sciences for data acquiring and parameter and lysis of climatology and oceanography is well developed. In this research we used the NOAA’s Satellite images from its AVHRR system to compare the field surface temperature data with the satellite images information. Ten satellite images were used in this project. These images were calibrated with the field data at the exact time of satellite pass above the area. The result was a significant relation between surface temperatures from satellite data with the field work. As the relative error less than %40 between these two data is acceptable, therefore in our observation the maximum error is %21.2 that can be considered it as acceptable. In all stations the result of satellite measurements is usually less than field data that cores ponds with the global result too. As this sea has a vast latitude, therefore the different in the temperature is natural. But we know this factor is not the only cause for surface currents. The information of all satellites were images extracted by ERDAS software, and the “Surfer” software is used to plot the isotherm lines.

Effect of the cation on the interactions between alkyl methyl imidazolium chloride ionic liquids and water

A systematic study of the interactions between water and alkyl methyl imidazolium chloride ionic liquids at 298.2 K, based on activity coefficients estimated from water activity measurements in the entire solubility range, is presented. The results show that the activity coefficients of water in the studied ILs are controlled by the hydrophilicity of the cation and the cation-anion interaction. To achieve a deeper understanding on the interactions between water and the ILs, COSMO-RS and FTIR spectroscopy were also applied. COSMO-RS was used to predict the activity coefficient of water in the studied ionic liquids along with the excess enthalpies, suggesting the formation of complexes between three molecules of water and one IL molecule. On the basis of quantum-chemical calculations, it is found that cation-anion interaction plays an important role upon the ability of the IL anion to interact with water. The changes in the peak positions/band areas of OH vibrational modes of water as a function of IL concentration were investigated, and the impact of the cation on the hydrogen-bonding network of water is identified and discussed.

Interactions of pyridinium, pyrrolidinium or piperidinium based ionic liquids with water: measurements and COSMO-RS modelling

Looking for a better knowledge concerning water and ionic liquids (ILs) interactions, a systematic study of the activity coefficients of water in pyridinium, pyrrolidinium and piperidinium-based ILs at 298.2 K is here presented based on water activity measurements. Additionally, the study of the structural effects of the pyridinium-based cation is also pursued. The results show that non-aromatic ILs are interacting more with water than aromatic ones, and among the ortho, meta and para isomers of 1-butyl-methylpyridinium chloride, the ortho position confers a more hydrophilic character to that specific IL. The physicalchemistry of the solutions was interpreted based on dissociation constants, natural bond orbitals and excess enthalpies providing a sound basis for the interpretation of the experimental observations. These results show that hydrogen bonding controls the behavior of these systems, being the anion-water one of the most relevant interactions, but modulated by the anionecation interactions.

Water sorption-induced crystallization, structural relaxations and strength analysis of relaxation times in amorphous lactose/whey protein systems

Water sorption-induced crystallization, α-relaxations and relaxation times of freeze-dried lactose/whey protein isolate (WPI) systems were studied using dynamic dewpoint isotherms (DDI) method and dielectric analysis (DEA), respectively. The fractional water sorption behavior of lactose/WPI mixtures shown at aw ≤ 0.44 and the critical aw for water sorption-related crystallization (aw(cr)) of lactose were strongly affected by protein content based on DDI data. DEA results showed that the α-relaxation temperatures of amorphous lactose at various relaxation times were affected by the presence of water and WPI. The α-relaxation-derived strength parameter (S) of amorphous lactose decreased with aw up to 0.44 aw but the presence of WPI increased S. The linear relationship for aw(cr) and S for lactose/WPI mixtures was also established with R2 > 0.98. Therefore, DDI offers another structural investigation of water sorption-related crystallization as governed by aw(cr), and S may be used to describe real time effects of structural relaxations in noncrystalline multicomponent solids.

Calibration and validation of wearable monitors

Background Wearable monitors are increasingly being used to objectively monitor physical activity in research studies within the field of exercise science. Calibration and validation of these devices are vital to obtaining accurate data. This article is aimed primarily at the physical activity measurement specialist, although the end user who is conducting studies with these devices also may benefit from knowing about this topic. Best Practices Initially, wearable physical activity monitors should undergo unit calibration to ensure interinstrument reliability. The next step is to simultaneously collect both raw signal data (e.g., acceleration) from the wearable monitors and rates of energy expenditure, so that algorithms can be developed to convert the direct signals into energy expenditure. This process should use multiple wearable monitors and a large and diverse subject group and should include a wide range of physical activities commonly performed in daily life (from sedentary to vigorous). Future Directions New methods of calibration now use "pattern recognition" approaches to train the algorithms on various activities, and they provide estimates of energy expenditure that are much better than those previously available with the single-regression approach. Once a method of predicting energy expenditure has been established, the next step is to examine its predictive accuracy by cross-validating it in other populations. In this article, we attempt to summarize the best practices for calibration and validation of wearable physical activity monitors. Finally, we conclude with some ideas for future research ideas that will move the field of physical activity measurement forward.

High-temperature, low-H₂O silicic magmas of the Yellowstone Hotspot: an experimental study of Rhyolite from the Bruneau-Jarbidge eruptive center, Central Snake River Plain, USA

The phase relations have been investigated experimentally at 200 and 500 MPa as a function of water activity for one of the least evolved (Indian Batt Rhyolite) and of a more evolved rhyolite composition (Cougar Point Tuff XV) from the 12·8-8·1 Ma Bruneau-Jarbidge eruptive center of the Yellowstone hotspot. Particular priority was given to accurate determination of the water content of the quenched glasses using infrared spectroscopic techniques. Comparison of the composition of natural and experimentally synthesized phases confirms that high temperatures (>900°C) and extremely low melt water contents (<1·5 wt % H₂O) are required to reproduce the natural mineral assemblages. In melts containing 0·5-1·5 wt % H₂O, the liquidus phase is clinopyroxene (excluding Fe-Ti oxides, which are strongly dependent on fO₂), and the liquidus temperature of the more evolved Cougar Point Tuff sample (BJR; 940-1000°C) is at least 30°C lower than that of the Indian Batt Rhyolite lava sample (IBR2; 970-1030°C). For the composition BJR, the comparison of the compositions of the natural and experimental glasses indicates a pre-eruptive temperature of at least 900°C. The composition of clinopyroxene and pigeonite pairs can be reproduced only for water contents below 1·5 wt % H₂O at 900°C, or lower water contents if the temperature is higher. For the composition IBR2, a minimum temperature of 920°C is necessary to reproduce the main phases at 200 and 500 MPa. At 200 MPa, the pre-eruptive water content of the melt is constrained in the range 0·7-1·3 wt % at 950°C and 0·3-1·0 wt % at 1000°C. At 500 MPa, the pre-eruptive temperatures are slightly higher (by 30-50°C) for the same ranges of water concentration. The experimental results are used to explore possible proxies to constrain the depth of magma storage. The crystallization sequence of tectosilicates is strongly dependent on pressure between 200 and 500 MPa. In addition, the normative Qtz-Ab-Or contents of glasses quenched from melts coexisting with quartz, sanidine and plagioclase depend on pressure and melt water content, assuming that the normative Qtz and Ab/Or content of such melts is mainly dependent on pressure and water activity, respectively. The combination of results from the phase equilibria and from the composition of glasses indicates that the depth of magma storage for the IBR2 and BJR compositions may be in the range 300-400 MPa (13 km) and 200-300 MPa (10 km), respectively.

Impact of the Australian litter re-use practice on Salmonella in the broiler farming environment

This study has examined the dynamics (in terms of levels and serovar diversity) of Salmonella in the "dual litter environment" that occurs within a single shed as a result of a management practice common in Australia. The study also looked at the physical parameters of the litter (pH, moisture content, water activity and litter temperature) as a means of understanding the Salmonella dynamics in these litter environments. The Australian practice results in the brooder end of the shed having new litter each cycle while the grow-out end has re-used litter (a "dual litter environment"). Two farms that adopted this partial litter re-use practice were studied over one full broiler cycle each. Litter was sampled weekly for the levels (and serovars) of Salmonella during a farming cycle. There was a trend for lower levels of Salmonella (and a lower Salmonella serovar) diversity in the re-used litter environment as compared with the new litter environment. Of the physical parameters examined, it would appear that the lower water activity associated with the re-used litter may contribute to the Salmonella dynamics in the dual environment.

Magmatic evolution of topaz-bearing granite stocks within the Wiborg rapakivi granite batholith

This study brings new insights into the magmatic evolution of natural F-enriched peraluminous granitic systems. The Artjärvi, Sääskjärvi and Kymi granite stocks within the 1.64 Ga Wiborg rapakivi granite batholith have been investigated by petrographic, geochemical, experimental and melt inclusion methods. These stocks represent late-stage leucocratic and weakly peraluminous intrusive phases typical of rapakivi granites worldwide. The Artjärvi and Sääskjärvi stocks are multiphase intrusions in which the most evolved phase is topaz granite. The Kymi stock contains topaz throughout and has a well-developed zoned structure, from the rim to the center: stockscheider pegmatite equigranular topaz granite porphyritic topaz granite. Geochemically the topaz granites are enriched in F, Li, Be, Ga, Rb, Sn and Nb and depleted in Mg, Fe, Ti, Ba, Sr, Zr and Eu. The anomalous geochemistry and mineralogy of the topaz granites are essentially magmatic in origin; postmagmatic reactions have only slightly modified the compositions. The Kymi equigranular topaz granite shows the most evolved character, and the topaz granites at Artjärvi and Sääskjärvi resemble the less evolved porphyritic topaz granite of the Kymi stock. Stockscheiders are found at the roof contacts of the Artjärvi and Kymi stocks. The stockscheider at Artjärvi is composed of biotite-rich schlieren and pegmatite layers parallel to the contact. The schlieren layering is considered to have formed by velocity-gradient sorting mechanism parallel to the flow, which led to the accumulation of mafic minerals along the upper contact of the topaz granite. Cooling and contraction of the topaz granite formed fractures parallel to the roof contact and residual pegmatite magmas were injected along the fractures and formed the pegmatite layers. The zoned structure of the Kymi stock is the result of intrusion of highly evolved residual melt from deeper parts of the magma chamber along the fractured contact between the porphyritic granite crystal mush and country rock. The equigranular topaz granite and marginal pegmatite (stockscheider) crystallized from this evolved melt. Phase relations of the Kymi equigranular topaz granite have been investigated utilizing crystallization experiments at 100 to 500 MPa as a function of water activity and F content. Fluorite and topaz can crystallize as liquidus phases in F-rich peraluminous systems, but the F content of the melt should exceed 2.5 - 3.0 wt % to facilitate crystallization of topaz. In peraluminous F-bearing melts containing more than 1 wt % F, topaz and muscovite are expected to be the first F-bearing phases to crystallize at high pressure, whereas fluorite and topaz should crystallize first at low pressure. Overall, the saturation of fluorite and topaz follows the reaction: CaAl2Si2O8 (plagioclase) + 2[AlF3]melt = CaF2 (fluorite) + 2Al2SiO4F2 (topaz). The obtained partition coefficient for F between biotite and glass D(F)Bt/glass is 1.89 to 0.80 (average 1.29) and can be used as an empirical fluormeter to determine the F content of coexisting melts. In order to study the magmatic evolution of the Kymi stock, crystallized melt inclusions in quartz and topaz grains in the porphyritic and the equigranular topaz granites and the marginal pegmatite were rehomogenized and analyzed. The homogenization conditions for the melt inclusions from the granites were 700 °C, 300 MPa, and 24 h, and for melt inclusions from the pegmatite, 700 °C, 100 MPa, and 24/96 h. The majority of the melt inclusions is chemically similar to the bulk rocks (excluding H2O content), but a few melt inclusions in the equigranular granite show clearly higher F and low K2O contents (on average 11.6 wt % F, 0.65 wt % K2O). The melt inclusion compositions indicate coexistence of two melt fractions, a prevailing peraluminous and a very volatile-rich, possibly peralkaline. Combined petrological, experimental and melt inclusion studies of the Kymi equigranular topaz granite indicate that plagioclase was the liquidus phase at nearly water-saturated (fluid-saturated) conditions and that the F content of the melt was at least 2 wt %. The early crystallization of biotite and the presence of muscovite in crystallization experiments at 200 MPa contrasts with the late-stage crystallization of biotite and the absence of muscovite in the equigranular granite, indicating that crystallization pressure may have been lower than 200 MPa for the granite.

Interruptions of (CG)n sequences by GG, TG and CA need not prevent B to Z transition in solution

Oligonucleotides containing alternating purines-pyrimidines with AT base pairs have been shown to exist in the Z-form preferably in solid state. We report that oligodeoxyribonucleotides with GG, TG and CA interruptions in their alternating CG sequences can undergo B to Z transition in solution in the absence of any chemical modification or topological constraint. The sequences, d(CGCGCGGCGCGC) and d(CGTGCGCACG) have been synthesised and shown to adopt Z- conformation in presence of millimolar concentrations of Ni2+ under low water activity conditions. Significance of GG, TG and CA interruptions in the B to Z transition is discussed.